Cell cycle arrest, apoptosis and p53 expression in nickel(II) acetate- treated Chinese hamster ovary cells

Nickel(II) compounds are known human and animal carcinogens. In this study, the effects of nickel(II) acetate on cell cycle, apoptosis and p53 expression were investigated in order to unveil the elements of early cellular responses to the metal. Chinese hamster ovary (CHO) cells were grown for 72 h in Ham's F-12 medium containing 0, 40, 80, 160, 240, 320, 480 or 640 microM nickel(II) acetate. DNA fragmentation, representative of apoptosis, was examined by agarose gel electrophoresis. The distribution of cells among various phases of cell cycle was determined by DNA flow cytometry. Expression of p53 protein was measured by the Western blotting technique. DNA fragmentation was detectable in cells treated with > or = 160 microM nickel(II) and its intensity increased with increasing nickel(II) concentration. The proportion of cells at S phase declined in a nickel(II) concentration- dependent manner. The decline was accompanied by an increase of cell proportion in G2/M phase and the increase became statistically significant in cells exposed to at least 480 microM nickel(II). Expression of p53 protein was not different from that in the control among samples treated with < or = 480 microM nickel(II). However, an extra fraction that migrated close to the p53 protein fraction was detected in cells treated with 640 microM nickel(II). Our findings suggest that nickel(II) modulates cellular response through effectors involved in both G2/M arrest and apoptosis regulatory pathways. The proportion of cells arrested at G2/M phase or undergoing apoptosis depends directly on nickel(II) concentration. High concentration of nickel(II) appears to up-regulate protein(s) other than the common form of p53 protein.      

N-(4-乙氧羰基-4-取代丁酰基)-N-取代甘氨酸的合成

本文报道9个估计具有血管紧张素转化酶抑制活性的N-(4-乙氧羰基-4-取代丁酰基)-N-取代甘氨酸及其相应叔丁酯的合成和鉴定。药理初试结果,化合物Ⅶ₇和Ⅶ₉显示明显降压活性。     

Waterloo Vision and Mobility Study: Normal gait characteristics during dark and light adaptation in individuals with age-related maculopathy

The purpose of this study was to evaluate the gait responses of individuals with low vision compared to those of normal-visioned individuals when their vision is challenged by extreme levels of light. Twenty subjects with age-related maculopathy (ARM) and 20 subjects with normal vision first walked along a flat, unobstructed path immediately after the ambient light level was changed from low (5 lux) to high (2500 lux). The procedure was repeated after the light was reduced from the high to the low level. Muscle activity, temporal and kinematic variables, and ground reaction forces were used to detect gait characteristics because of ambient light level changes. Data suggested that ARM subjects walked slower and with more caution than normal subjects but that these differences were not related to ambient light level. Head angle, an estimate of gaze direction, was lower for ARM subjects during high light, but the gaze direction for both groups was low during low light. Among these ARM subjects, extreme levels of ambient light did not affect gait; subjects made adaptations that were reasonable to encourage safe ambulation, despite the direction of light change. Normal-visioned individuals in this study experienced more difficulty in low light than high light situations.     

AUDIT OF PATIENT ACCEPTANCE OF NASAL SURGERY AS A DAY CASE PROCEDURE

SUMMARY A greater emphasis on day case surgery within the health service is seen as a method of improving efficiency and reducing expenditure. We interviewed 90 consecutive patients undergoing nasal surgery who had been preoperatively assessed as being fit for day case surgery. They were randomised into three groups regarding the duration of postoperative nasal packing. All patients stayed overnight following surgery and were interviewed prior to discharge. Some 52% of the overall sample would be happy to have nasal surgery performed as a day case. If the nasal pack was removed after two hours, this figure rose to 67%. This difference in patient acceptance did not attain statistical significance overall, but there was a significant difference in those undergoing submucosal resection. There was no difference in the age, sex distribution or type of surgery performed between each group. The audit commission quotes patient satisfaction with day case surgery at 80%. Nasal surgery was not examined in their report, but was included as one of a set of procedures suitable for consideration. Although day case nasal surgery may be safe, further research regarding patient acceptance is required.     

The athlete’s heart: Is this an entity in paediatrics?

A case report of a boy who demonstrates features of an athlete's heart, associated with dilatation of the coronary artery, is presented. The importance of distinguishing this benign condition from pathologic causes such as cardiomyopathy, and risk of sudden death in these athletes is discussed.