MEASUREMENTS OF INTERFACE PRESSURE BETWEEN BODY SITES AND THE SURFACES OF FOUR SPECIALISED AIR MATTRESSES

SUMMARY Four specialised air mattresses had interface pressure measured under six body sites prone to pressure sores in 10 subjects, supine and sitting. The mattresses were the Clinirest (SSI) and FirstStep (KCI) continuous airflow mattress overlays, and Airwave (Pegasus) and Nimbus (Huntleigh) alternating pressure air mattresses. On the mattress overlays, average supine interface pressures were 2.33 kPa (scapula), 4.15 kPa (elbow), 1.94 kPa (sacrum) and 2.79 kPa (buttock), although they were higher at the occiput (7.97 kPa) and heel (11.7 kPa). The alternating pressure air mattresses had an average minimum interface pressure close to zero for three sites, rising to 4.28 kPa under the heel. Average maximum interface pressures were 8.61 kPa (occiput), 5.21 kPa (scapula), 4.90 (elbow), 4.85 kPa (sacrum), 4.61 kPa (buttock) and 13.2 kPa (heel). No accepted scientific method exists for comparing the two types of mattress. Our data suggest a clinical benefit at the occiput and heel (supine) in using an alternating pressure air mattress and a benefit in using a continuous airflow mattress overlay at other sites.     

A humanised tissue‐engineered bone model allows species‐specific breast cancer‐related bone metastasis in vivo

Bone metastases frequently occur in the advanced stages of breast cancer. At this stage, the disease is deemed incurable. To date, the mechanisms of breast cancer‐related metastasis to bone are poorly understood. This may be attributed to the lack of appropriate animal models to investigate the complex cancer cell–bone interactions. In this study, two established tissue‐engineered bone constructs (TEBCs) were applied to a breast cancer‐related metastasis model. A cylindrical medical‐grade polycaprolactone‐tricalcium phosphate scaffold produced by fused deposition modelling (scaffold 1) was compared with a tubular calcium phosphate‐coated polycaprolactone scaffold fabricated by solution electrospinning (scaffold 2) for their potential to generate ectopic humanised bone in NOD/SCID mice. While scaffold 1 was found not suitable to generate a sufficient amount of ectopic bone tissue due to poor ectopic integration, scaffold 2 showed excellent integration into the host tissue, leading to bone formation. To mimic breast cancer cell colonisation to the bone, MDA‐MB‐231, SUM1315, and MDA‐MB‐231BO breast cancer cells were cultured in polyethylene glycol‐based hydrogels and implanted adjacent to the TEBCs. Histological analysis indicated that the breast cancer cells induced an osteoclastic reaction in the TEBCs, demonstrating analogies to breast cancer‐related bone metastasis seen in patients.     

004 65岁以上收缩功能正常的心衰者的临床特点

众所周知,充血性心衰(CHF)为老年人较为常见的临床综合征之一.迄今关于左室收缩功能正常的CHF老人的相关临床特点远未清楚,本文特此进行了大样本分析. 对象与方法 4842例老年人,男1922例,女2920例,年龄66～103岁.尔后人均随访1年.旨在分析老年CHF年发病率,以及左室收缩功能正常的CHF老人相关临床特点. 结果随访期内,罹发1次或以上CHF者共425例次(8.8%/年).与未患发CHF老人相比,CHF老人平均年龄更大(79±6岁:77±5岁,P＜0.001),女性居多,尤以高龄女性更多,如85岁以上的高龄女性CHF年发病率约较65～69岁女性高2倍(14%∶6.6%,P＜0.001),AMI史、房颤、高血压、糖尿病、慢性阻塞型肺病、吸烟者均多,血脂及血肌酐亦高.多变量分析表明,罹患CHF与下列因素有关:老年尤其是高龄[年龄每增加5岁的患病奇数率(OR)女性1.2,男性1.1],AMI史(OR7.3),房颤者(OR3.0),糖尿病(OR2.1),肾功能不全(血肌酐≥1.5mg/dl的OR2.0),慢性阻塞肺病(仅老年女性的OR为1.8),以及左房、左室内径增大(内径每递增1cm的OR为2.0),和左室重量增加、左室收缩末期室壁张力增高、早期跨心房血流增多.超声心动图检测结果显示,CHF老人中,左室收缩功能正常者达55%,而仅有左室舒张功能不全,且左室收缩功能正常或轻度减退者高达80%.其中女性左室收缩功能正常者尤较男性多见(67%∶42%,P＜0.001),表现为单纯左室舒张功能不良.而在左室收缩功能正常的CHF老人,常伴有左室内径较小、左室收缩末期室壁张力较低、左室重量较轻、左室收缩末期室壁厚度增加,而左室射血分数正常或仅轻度降低. 讨论以上结果提示,在老年人群中,CHF年发病率相对较高,且随年龄而增加,多数左室收缩功能正常,仅有左室舒张功能障碍,尤其是在高龄女性,亦即高龄女性左室舒张功能不全性CHF更为常见.对此,临床上更应拟出合理的防范措施,来正确诊治老年CHF综合征. (袁志敏摘)