In Vivo Measures of Shear Wave Speed as a Predictor of Tendon Elasticity and Strength

The purpose of this study was to assess the potential for ultrasound shear wave elastography (SWE) to measure tissue elasticity and ultimate stress in both intact and healing tendons. The lateral gastrocnemius (Achilles) tendons of 41 New Zealand white rabbits were surgically severed and repaired with growth factor coated sutures. SWE imaging was used to measure shear wave speed (SWS) in both the medial and lateral tendons pre-surgery, and at 2 and 4 wk post-surgery. Rabbits were euthanized at 4 wk, and both medial and lateral tendons underwent mechanical testing to failure. SWS significantly (p < 0.001) decreased an average of 17% between the intact and post-surgical state across all tendons. SWS was significantly (p < 0.001) correlated with both the tendon elastic modulus (r = 0.52) and ultimate stress (r = 0.58). Thus, ultrasound SWE is a potentially promising non-invasive technology for quantitatively assessing the mechanical integrity of pre-operative and post-operative tendons.     

腔内修复术治疗破裂性腹主动脉瘤的疗效及技巧探讨

目的观察腔内修复术(EVAR)治疗破裂性腹主动脉瘤(RAAA)的疗效,并探讨手术经验与技巧。方法 2009年1月—2013年12月收治的RAAA患者12例,均于全身麻醉后行EVAR,经一侧股动脉穿刺置管造影,沿肾动脉下方通过输送器植入支架。结果 12例患者中,8例(66.67%)植入分叉型人工血管内支架,4例(33.33%)植入直型支架;平均手术时间(170.35±15.34)min,平均出血量和输血量分别为(92.55±8.67)m L和(301.58±16.39)m L。术中无死亡病例,术后2例(16.67%)死亡;主要并发症为心律失常、肺部感染、肾功能损害等,并发症总发生率58.33%;1例(10.00%)患者于术后26个月出现Ⅰa型内漏,再次行栓塞治疗。结论 EVAR是RAAA的有效救治方式,术前血管造影检查对保证手术效果至关重要。     

Worldwide Distribution of Four SNPs in X‐Ray and Repair and Cross‐Complementing Group 1 (XRCC1)

Purpose

X‐ray repair cross‐complementing group 1 (XRCC1) repairs single‐strand breaks in DNA. Several reports have shown the association of single nucleotide polymorphisms (SNPs) (Arg194Trp, Pro206Pro, Arg280His, Arg399Gln) in XRCC1 to diseases. Limited population data are available regarding SNPs in XRCC1, especially in African populations. In this study, genotype distributions of four SNPs in worldwide populations were examined and compared with those reported previously.

Materials and Methods

Four SNPs (Arg194Trp, Pro206Pro, Arg280His, Arg399Gln) in XRCC1 from genomic DNA samples of 10 populations were evaluated by using polymerase chain reaction followed by restriction fragment length polymorphism analysis.

Results

The frequency of the minor allele corresponding to the Trp allele of XRCC1Arg194Trp was higher in Asian populations than in African and Caucasian populations. As for XRCC1Pro206Pro, Africans showed higher minor allele frequencies than did Asian populations, except for Tamils and Sinhalese. XRCC1 Arg280His frequencies were similar among Africans and Caucasians but differed among Asian populations. Similarly, lower mutant XRCC1 Arg399Gln frequencies were observed in Africans.

Conclusions

This study is the first to show the existence of a certain genetic heterogeneity in the worldwide distribution of four SNPs in XRCC1.     

Surface-displayed glyceraldehyde 3-phosphate dehydrogenase and galectin from Dirofilaria immitis enhance the activation of the fibrinolytic system of the host

Cardiopulmonary dirofilariosis is a cosmopolitan disease caused by Dirofilaria immitis, a filaroid parasite whose adult worms live for years in the vascular system of its host. Previous studies have shown that D. immitis can use their excretory/secretory (ES) and surface antigens to enhance fibrinolysis, which could limit the formation of clots in its surrounding environment. Moreover, several isoforms of the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and galectin (GAL) were identified in both antigenic extracts as plasminogen-binding proteins. The aim of this work is to study the interaction of the GAPDH and GAL of D. immitis with the fibrinolytic system of the host. This study includes the cloning, sequencing and expression of the recombinant forms of the GAPDH and GAL of D. immitis (rDiGAPDH and rDiGAL) and the analysis of their capacity as plasminogen-binding proteins. The results indicate that rDiGAPDH and rDiGAL are able to bind plasminogen and stimulate plasmin generation by tissue plasminogen activator (tPA). This interaction needs the involvement of lysine residues, many of which are located externally in both proteins as have been shown by the molecular modeling of their secondary structures. In addition, we show that rDiGAPDH and rDiGAL enhance the expression of the urokinase-type plasminogen activator (uPA) on canine endothelial cells in culture and that both proteins are expressed on the surface of D. immitis in close contact with the blood of the host. These data suggest that D. immitis could use the associated surface GAPDH and GAL as physiological plasminogen receptors to shift the fibrinolytic balance towards the generation of plasmin, which might constitute a survival mechanism to avoid the clot formation in its intravascular habitat.     

Choc cardiogénique sur bicuspidie aortique sténosante traité par remplacement valvulaire aortique percutané en urgence

Transcatheter aortic valve implantation is a therapeutic option for high-risk patients with severe aortic valve stenosis and with cardiac symptoms. This procedure requires the preliminary evaluation by a “heart team” and presents some contraindications. We report the case of a 58-year-old man with severe bicuspid aortic valve stenosis and cardiogenic shock. In spite of contraindications and because of the failure of balloon aortic valvuloplasty, transcatheter aortic valve implantation was performed in emergency.     

Wound repair during arm regeneration in the red starfish Echinaster sepositus

Starfish can regenerate entire arms following their loss by both autotomic and traumatic amputation. Although the overall regenerative process has been studied several times in different asteroid species, there is still a considerable gap of knowledge as far as the detailed aspects of the repair phase at tissue and cellular level are concerned, particularly in post‐traumatic regeneration. The present work is focused on the arm regeneration model in the Mediterranean red starfish Echinaster sepositus; to describe the early cellular mechanisms of arm regeneration following traumatic amputation, different microscopy techniques were employed. In E. sepositus, the repair phase was characterized by prompt wound healing by a syncytial network of phagocytes and re‐epithelialisation followed by a localized subepidermal oedematous area formation. Scattered and apparently undifferentiated cells, intermixed with numerous phagocytes, were frequently found in the wound area during these first stages of regeneration and extensive dedifferentiation phenomena were seen at the level of the stump, particularly in the muscle bundles. A true localized blastema did not form. Our results confirm that regeneration in asteroids mainly relies on morphallactic processes, consisting in extensive rearrangement of the existing tissues which contribute to the new tissues through cell dedifferentiation, redifferentiation, and/or migration.     

Endovascular Approach to Acute Hemorrhage in Locally Advanced Breast Cancer

We report a case of a woman with recurrent axillary fungating breast cancer who developed catastrophic hemorrhage from tumor erosion of her axillary artery. This was treated successfully with endovascular placement of a covered arterial stent. We discuss the suitability of endovascular therapy for patients with advanced malignancy given its lower morbidity in this population with decreased life expectancy.     

Teaching facial fracture repair: A novel method of surgical skills training using three-dimensional biomodels

BACKGROUND:

The facial fracture biomodel is a three-dimensional physical prototype of an actual facial fracture. The biomodel can be used as a novel teaching tool to facilitate technical skills training in fracture reduction and fixation, but more importantly, can help develop diagnostic and management competence.

OBJECTIVE:

To introduce the ‘facial fracture biomodel’ as a teaching aid, and to provide preliminary evidence of its effectiveness in teaching residents the principles of panfacial fracture repair.

METHODS:

Computer three-dimensional image processing and rapid prototyping were used to generate an accurate physical model of a panfacial fracture, mounted in a silicon ‘soft tissue’ base. Senior plastic surgery residents in their third, fourth and fifth years of training across Canada were invited to participate in a workshop using this biomodel to simulate panfacial fracture repair. A short didactic presentation outlining the ‘patient’s’ clinical and radiological findings, and key principles of fracture repair, was given by a consultant plastic surgeon before the exercise. The residents completed a pre- and postbiomodel questionnaire soliciting information regarding background, diagnosis and management, and feedback.

RESULTS:

A total of 29 residents completed both pre- and postbiomodel questionnaires. Statistically significant results were found in the following areas: diagnosis of all fracture patterns (P=8.2×10⁻⁷ [t test]), choice of incisions for adequate exposure (P=0.04 [t test]) and identifying sequence of repair (P=0.019 [χ² test]). Subjective evaluation of workshop effectiveness revealed a statistically significant increase in ‘comfort level’ only among third year trainees. Overall, positive feedback was reported among all participants.

CONCLUSIONS:

Biomodelling is a promising ancillary teaching aid that can assist in teaching residents technical skills, as well as how to assess and plan surgical repair.