An intersegmental reflex between the copulatory swimmerets of the male squat lobster,Galathea strigosa

The structure of the sexually modified 1st 2 pairs of swimmerets of the male squat lobster Galathea strigosa are described, and a reflex involving these swimmerets is characterised. The endopodite of the 1st swimmeret forms a partially rolled lamina which hooks around the “bottle brush” end of the endopodite of the 2nd swimmeret. Mechanical stimulation of a sensitive region on the endopodite of each 1st swimmeret causes retraction of both 2nd swimmerets, inducing the “bottle brush” to push up within the endopodite of the 1st swimmeret. The reflex is thought to be involved in sperm transfer during copulation. Neural information travels between the 1st and 2nd swimmerets in the interganglionic connective ipsilateral to the stimulus.     

Intraoperative Biomechanical Registration of the Liver: Does the Heterogeneity of the Liver Matter?

Background: Preoperative images such as computed tomography scans or magnetic resonance imaging contain lots of valuable information that are not easily available for surgeons during an operation. To help the clinicians better target the structures of interest during an intervention, many registration methods that align preoperative images onto the intraoperative view of the organs have been developed. For important organ deformation, biomechanically-based registration has proven to be a method of choice.Method: Using an existing biomechanically-based registration algorithm for laparoscopic liver surgery we investigate in this paper the influence of the heterogeneity of the liver on the registration result.Results: No statistical difference in the results was found between the registration performed with the homogeneous model and the one carried out with the heterogeneous model.Conclusion: As the use of an heterogeneous model does not improve significantly the registration result and increase the computation time we recommend to perform the type of registration task described in the paper with a simplified homogeneous model.     

Glycocalyx damage biomarkers in healthy controls,abdominal surgery,and sepsis: a scoping review

Abstract

Objective

Despite wide interest in glycocalyx biomarkers, their values in healthy individuals, patients after abdominal surgery, and septic patients have been poorly understood.     

A multiparametric approach to discriminate the impacts of different degrees of invasiveness of surgical procedures in sheep

Traumatic situations in animals induce responses including pain, expressed through behavioural and physiological pathways such as inflammation, oxidative stress, hypothalamic–pituitary–adrenal (HPA) axis and autonomic nervous system. As some of these systems can also be activated during excitement and situations with a positive valence, their use as a means to assess pain response is difficult. We explored (i) how these five aforementioned pathways change in sheep exposed to various degrees of invasiveness of surgical procedures despite a therapeutic regimen and (ii) whether a multiparametric analysis that combines information from these five pathways enhances the discrimination between these situations, and estimates the relative importance of these pathways in the response. We used 24 adult sheep split into four treatments: Control (C; no fasting, no anaesthesia, no surgery), Sham (S; fasting, anaesthesia, no surgery), Rumen Canulation (R; fasting, anaesthesia, rumen cannulation) and Rumen–Duodenal–Ileum cannulation (RDI; fasting, anaesthesia, cannulation of the rumen, duodenum and ileum). Sheep’ responses were measured for 5 days after surgery. When considering each behavioural or physiological pathway independently, discrimination between treatments was acceptable, its sensitivity (Se) ranging from 0% to 100%, and its specificity (Sp) ranging from 62% to 100%. The multiparametric analysis gathering information from the five pathways enhanced the effectiveness of discrimination between treatments (Se, 50% to 100%; Sp, 82% to 100%), and gave additional information on the relative contribution of each pathway to the global sheep response. Sheep global response was higher when exposed to a surgery, and increased with the surgery invasiveness. This response relied mostly on inflammation (absolute correlation for haptoglobin, 0.89), HPA (cortisol, 0.85) and behaviour (antalgic postures, 0.85). The multiparametric approach seems to be a promising tool to discriminate between different degrees of invasiveness of surgical procedures.     

Effects of femoral component placement on the balancing of a total knee at surgery

Misalignment and soft-tissue imbalance in total knee arthroplasty (TKA) can cause discomfort, pain, inadequate motion and instability that may require revision surgery. Balancing can be defined as equal collateral ligament tensions or equal medial and lateral compartmental forces during the flexion range. Our goal was to study the effects on balancing of linear femoral component misplacements (proximal, distal, anterior, posterior); and different component rotations in mechanical alignment compared to kinematic alignment throughout the flexion path. A test rig was constructed such that the position of a standard femoral component could be adjusted to simulate the linear and rotational positions. With the knee in neutral reference values of the collateral tensions were adjusted to give anatomic contact force patterns, measured with an instrumented tibial trial. The deviations in the forces for each femoral component position were then determined. Compartmental forces were significantly influenced by 2 mm linear errors in the femoral component placement. However, the errors were least for a distal error, equivalent to undercutting the distal femur. The largest errors mainly increase the lateral condyle force, occurred for proximal and posterior component errors. There were only small contact force differences between kinematic and mechanical alignment. Based on these results, surgeons should avoid overcutting the distal femur and undercutting the posterior femur. However, the 2–3 degrees varus slope of the joint line as in kinematic alignment did not have much effect on balancing, so mechanical or kinematic alignment were equivalent.     

微创后入路治疗肩胛骨骨折的临床研究

目的:探讨微创后入路手术治疗肩胛骨骨折的临床疗效。方法:选取2009年6月~2014年1月在我院接受后路内固定手术治疗的40例肩胛骨骨折,治疗组20例,行微创后入路内固定术,对照组20例,行Judet入路内固定术。比较两组间手术时间、术中出血量、切口总长度及术后肩关节功能Constant评分。结果:40例患者均获随访,随访时间12~36个月,平均16.5个月。治疗组手术时间、术中出血量、切口总长度均优于对照组(均P0.05),术后6个月肩关节功能:治疗组优15例,良3例,可1例,差1例,优良率90%,对照组优14例,良2例,可3例,差1例,优良率80%。两组优良率比较,差异有统计学意义(P0.05)。两组均无感染、骨折延迟愈合或不愈合。对照组1例发生肩胛上神经卡压。结论:微创后入路手术操作简单,创伤小,恢复快,是一种安全有效的肩胛骨骨折手术入路。     

Decreased Bioenergetic Health Index in monocytes isolated from the pericardial fluid and blood of post-operative cardiac surgery patients

Monitoring the bioenergetics of leucocytes is now emerging as an important approach in translational research to detect mitochondrial dysfunction in blood or other patient samples. Using the mitochondrial stress test, which involves the sequential addition of mitochondrial inhibitors to adherent leucocytes, we have calculated a single value, the Bioenergetic Health Index (BHI), which represents the mitochondrial function in cells isolated from patients. In the present report, we assess the BHI of monocytes isolated from the post-operative blood and post-operative pericardial fluid (PO-PCF) from patients undergoing cardiac surgery. Analysis of the bioenergetics of monocytes isolated from patients’ PO-PCF revealed a profound decrease in mitochondrial function compared with monocytes isolated from their blood or from healthy controls. Further, patient blood monocytes showed no significant difference in the individual energetic parameters from the mitochondrial stress test but, when integrated into the BHI evaluation, there was a significant decrease in BHI compared with healthy control monocytes. These data support the utility of BHI measurements in integrating the individual parameters from the mitochondrial stress test into a single value. Supporting our previous finding that the PO-PCF is pro-oxidant, we found that exposure of rat cardiomyocytes to PO-PCF caused a significant loss of mitochondrial membrane potential and increased reactive oxygen species (ROS). These findings support the hypothesis that integrated measures of bioenergetic health could have prognostic and diagnostic value in translational bioenergetics.     

A novel in vivo Cerenkov luminescence image‐guided surgery on primary and metastatic colorectal cancer

Intraoperative Cerenkov luminescence imaging (CLI) can effectively improve the performance of tumor surgery. Nevertheless, the existing approaches are still unsatisfying to the clinical demands of open surgery. This study develops a novel intraoperative in vivo CLI approach to investigate the potential and value of Cerenkov luminescence (CL) image‐guided surgery. A system characterized with high sensitivity (19.61 kBq mL^{?1 18}F‐FDG) and desirable spatial resolution (88.34 μm) is developed. CL image‐guided surgery is performed on colorectal cancer (CRC) models of mice and swine. Tumor surgery is guided by the static CL images, and the resection quality is evaluated quantitatively and contrasted with other imaging modalities exemplified by bioluminescence imaging (BLI). The in vivo results demonstrated the effectiveness of the proposed intraoperative CLI approach for removing primary and metastatic CRC. Safety of performing in vivo CL image‐guided surgery is verified as well through radiation measurements of related staffs. Overall, the developed intraoperative in vivo CLI approach can efficiently improve the cancer treatment.     

An integrated haptic-enabled virtual reality system for orthognathic surgery planning

Conventional Orthognathic surgery (OGS) planning involves cephalometric analyses and dental casts to be mounted on an articulator. Dental segments are subsequently identified, cut and repositioned to allow the fabrication of intraoral wafers that guide the positioning of the osteotomy bone segments. This conventional planning introduces many inaccuracies that affect the post-surgery outcomes. Although computer technologies have advanced computational tools for OGS planning, they have failed in providing a practical solution. Many focuses only on some specific stages of the planning process, and their ability to transfer preoperative planning data to the operating room is limited. This paper proposes a new integrated haptic-enabled virtual reality (VR) system for OGS planning. The system incorporates CAD tools and haptics to facilitate a complete planning process and is able to automatically generate preoperative plans. A clinical pre-diagnosis is also provided automatically by the system based on the patient’s digital data. A functional evaluation based on a real patient case study demonstrates that the proposed virtual OGS planning method is feasible and more effective than the traditional approach at increasing the intuitiveness and reducing errors and planning times.