Construction and in vivo evaluation of a dual layered collagenous scaffold with a radial pore structure for repair of the diaphragm

In each organ the extracellular matrix has a specific architecture and composition, adapted to the functional needs of that organ. As cells are known to respond to matrix organization, biomaterials that take into account the specific architecture of the tissues to be regenerated may have an advantage in regenerative medicine. In this study we focussed on the diaphragm, an organ essential for breathing, and consisting of radial oriented skeletal muscle fibres diverging from a central tendon plate. To mimic this structure dual layered collagenous scaffolds were constructed with a radial pore orientation, prepared by inward out freezing, and reinforced by a layer of compressed collagen. Similar scaffolds with a random round pore structure were taken as controls. Scaffolds were first mildly crosslinked by formaldehyde vapour fixation for initial stabilization (13% and 17% crosslinking for the radial and control scaffolds, respectively), and further crosslinked using aqueous 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (38% and 37% crosslinking, respectively). Scaffolds were implanted into a surgically created diaphragm defect in rats and explanted after 12 weeks. Macroscopically, integration of the radial scaffolds with the surrounding diaphragm was better compared with the controls. Cells had infiltrated further into the centre of the scaffolds (P = 0.029) and there was a tendency of blood vessels to migrate deeper into the radial scaffolds (P = 0.057, compared with controls). Elongated cells (SMA-positive) were aligned with the radial structures. In conclusion, collagenous scaffolds with a stable radial pore structure can be constructed which facilitate cellular in-growth and alignment in vivo.     

甲状腺疾病手术消毒前超声定位的临床应用

目的 探讨手术消毒前超声定位在甲状腺疾病的手术治疗中的临床实用价值.方法 对80例甲状腺多发结节患者,于手术消毒前由术者行超声定位,观测病灶个数、病灶于上下极分布情况以及距后包膜的距离;并对病灶手术切除率、手术探查时间、声嘶、低钙并发症发生率进行统计,与未行超声定位的80例甲状腺多发结节患者进行对照.结果 80例患者术中按超声所观测数据确定的位置均能迅速找到病灶,病灶切除率为93.75％(75/80),多发性结节患者能缩短探查时间,结节距离后包膜5 mm以上者无需费时显露保护喉返神经,仅70.00％(56/80)显露喉返神经.未使用超声定位组对5 mm以下位置非表浅结节,均只能留作随访,病灶切除率76.25％(61/80),对临床可疑恶性、探查无法触及者,仅能做大范围切除活检(同侧叶次全切除),喉返神经显露达92.50％(74/80).在手术探查时间、病灶切除率和喉返神经显露率方面两组间的差异有统计学意义(P＜0.01).两组中除1例因癌结节位于喉返神经入喉处术后出现声音略低外,均未发生严重并发症.结论 甲状腺疾病麻醉后消毒前超声定位,有助于了解甲状腺病灶的数量及与周围组织的三维关系,有利于术中迅速找到并准确切除病灶,是一种既能提高手术精确性、提高病灶切除率,又能降低手术难度的实用性很强的方法.     

The effect of orientation on prehension movement time

We explored the relationship between hand orientation and movement time. Three groups of participants (n = 8 per group) were asked to grasp an object rotated in one of the following planes: (1) coronal; (2) sagittal; (3) horizontal. In the coronal plane, the rotational requirements directly mapped onto the neuromuscular demands associated with a single joint-level degree of freedom movement. A simple lawful relationship was found between the extent of rotation (pronation or supination) and duration. Reach-to-grasp movements to objects rotated in the sagittal and horizontal plane produced different movement patterns. These patterns increased the muscle level degrees of freedom recruited (higher neuromuscular demands) and movement duration increased correspondingly though not in a simple manner. The results of the present study show unambiguously that object orientation influences the duration of reach-to-grasp movements.     

Development of visual texture segregation during the first year of life: a high-density electrophysiological study

There are important developmental changes occurring during infancy in visual cortical structures that underlie higher-order perceptual abilities. Using high-density electrophysiological recording techniques, the present study aimed to examine the development of visual mechanisms, during the first year of life, associated with texture segregation. Forty-two normal full term infants were tested at 1, 3, 6 or 12 months of age. Visual-evoked potentials to low-level stimuli varying in orientation (oriVEP) and higher-level textured stimuli (texVEP) were recorded from 128 scalp electrodes. Difference potentials were obtained to extract the VEP component associated specifically with texture segregation (tsVEP). Results show a clear developmental pattern regarding amplitude, latency and scalp distribution of tsVEP, which appears at around 3 months but does not reach maturity by 12 months of age. A reduction in latency is particularly evident between 3 and 6 months, whereas amplitude shows a gradual increase with a marked increment between 3 and 6 months for low-level orientation stimuli and between 6 and 12 months for higher-level textured stimuli. These developmental patterns are attributed to neural maturational processes such as myelination and synaptogenesis. The differential developmental rates can be explained by delayed maturational processes of brain regions involved in more complex visual processing.     

卫生监督的价值取向与违法打击的行政责任伦理问题初探

作者初步介绍卫生监督部门的价值取向与行政责任伦理关系,表明培养卫生监督员的责任伦理观念,加强卫生行政部门的责任伦理制度建设,是推动卫生监督行政责任伦理实现的主要途径。     

术前超声定位在微型腹腔镜甲状腺切除术中的临床应用

目的:探讨术前超声定位在微型腹腔镜甲状腺切除术前后的可行性和临床实用价值。方法:对30例甲状腺结节患者,测量结节与气管内侧缘的距离、与前包膜的距离、与上下极平面的距离;并对手术的结节切除率、手术时间、术中出血量、住院时间进行分析。结果:29例患者于腔镜术中按超声所测数据确定的位置均能迅速找到结节,结节切除率97.2%,除1例发生一过性声音嘶哑外,无一例发生严重并发症。结论:术前超声检查有助于了解甲状腺结节及其周围情况,术前测量定位数据有利于微型腹腔镜甲状腺切除术中迅速找到并切除结节,是一种安全可行和预防并发症发生的有效途径。     

Tweed技术在安氏Ⅱ类1分类错畸形拔牙矫治中的疗效观察

目的:探讨Tweed-Merrifield技术治疗安氏Ⅱ类1分类错的临床效果。方法:取自太和医院口腔正畸科2009年以来诊治的50例安氏Ⅱ类1分类错患者,通过对患者的临床检查、模型分析、头影测量分析、Tweed分析之后拔除上颌两个第一前磨牙、下颌两个第二前磨牙,采用Tweed-Merrifield固定矫治技术,观察矫治前后软硬组织及侧貌的变化。结果:治疗结束后48例患者双侧上下牙列排列整齐,覆覆盖正常,双侧磨牙关系中性,侧貌改善,患者本人及家长对矫治效果满意。结论:方丝弓是一种有效的矫治安氏Ⅱ类1分类错的固定矫治器,在治疗中应用Tweed技术时应掌握好力的使用及支抗的控制。