Ca2+ wave activity was monitored in the longitudinal (LM) layer of isolated murine caecum and proximal colon at 35 °C with fluo‐4 AM and an iCCD camera. Both intracellular (within LM cells) and intercellular (also spreading from cell to cell) Ca2+ waves were observed. Intracellular Ca2+ waves were associated with a lack of muscle movement whereas intercellular Ca2+ waves, which were five times more intense than intracellular waves, were often associated with localized contractions. Several intracellular Ca2+ waves were present at the same time in individual LM cells. Waves in adjacent LM cells were not coordinated and were unaffected by TTX (1 μM) but were blocked by IP3 receptor antagonists xestospongin‐C (Xe‐C; 2 μM) or 2‐aminoethyl diphenylborate (2‐APB; 25 μM), and by ryanodine (10 μM). Caffeine (5 mm) restored wave activity following blockade with Xe‐C. NiCl2 (1 mm) blocked intracellular Ca2+ waves, and nicardipine (2 μM) reduced their frequency and intensity, but did not affect their velocity, suggesting the sarcoplasmic reticulum may be fuelled by extracellular Ca2+ entry. Intercellular Ca2+ waves often occurred in bursts and propagated rapidly across sizeable regions of the LM layer and were blocked by heptanol (0.5 mm). Intercellular Ca2+ waves were dependent upon neural activity, external Ca2+ entry through L‐type Ca2+ channels, and amplification via calcium‐induced calcium release (CICR). In conclusion, intracellular Ca2+ waves, which may reduce muscle excitability, are confined to individual LM cells. They depend upon Ca2+ release from internal Ca2+ stores and are likely to be fuelled by extracellular Ca2+ entry. Intercellular Ca2+ waves, which are likely to underlie smooth muscle tone, mixing and propulsion, depend upon neural activity, muscle action potential propagation and amplification by CICR.
We investigated the involvement of muscle tone and circular muscle (CM) contraction in peristalsis in isolated guinea‐pig small intestine. A segment of jejunum (≈13 cm) was mounted into a three chambered partitioned bath. Peristaltic waves were initiated in the oral chamber eitherby: (1) infusing fluid into the oral end of the jejunum; the ejected fluid was diverted via a cannula from reaching the intermediate and anal chambers, or by (2) intraluminal balloon distension of the empty oral segment. Tension of the circular muscle was measured in all three chambers. Peristaltic waves elicited by fluid infusion were evoked at an abrupt threshold. In contrast, peristaltic waves elicited by distension could be graded in amplitude according to stimulus intensity. Peristaltic waves evoked in an empty intestine exhibited similar propagation velocities to peristaltic waves associated with fluid propulsion. Nifedipine (200‐400 nM) added to the intermediate chamber to block muscle contraction did not prevent peristaltic waves elicited by either stimulus from propagating into the anal chamber, although their amplitude was attenuated. Nifedipine to the site of stimulation (oral chamber) abolished peristaltic waves generated by either stimulus. Tetrodotoxin (1‐2 μM), or a low Ca2+‐high Mg2+ solution to the intermediate chamber abolished the propagation of peristalsis from the oral to anal chambers. In conclusion, graded peristaltic waves can occur in an empty intestine. Therefore peristalsis is not necessarily an ‘all‐or‐none’ phenomenon. Peristalsis depends on the spread of nervous activity along the bowel, rather than the reactivation of neural circuits caused by displacement of fluid in the lumen. However, local muscle tone and contraction are important for the initiation and maintenance of peristaltic propagation.
BACKGROUND: Direct Socket for transfemoral (DS-TF) prosthetic user is a novel method of fabricating a laminated interface on to the residual limb but requires different training, production method and service model than what most prosthetists are familiar with. This method and model may improve patient satisfaction by enabling interface fabrication and delivery in one visit. OBJECTIVES: Document patient satisfaction regarding DS-TF interface versus the prosthetic users’ previous socket in terms of interface function and the clinic service model. METHODOLOGY: In this longitudinal study (from July 2018 to April 2020), the DS-TF was implemented in six prosthetic clinics across the United States. Certified prosthetists (CP) and assistants were trained using a standard protocol. 47 prosthetic users participated, both those in need of a new socket and those without need. Two modules from the Orthotics and Prosthetics Users’ Survey (OPUS), involving questions related to satisfaction with the Device and Services, was used to evaluate each DS-TF user outcome vs. baseline. The only part of the prosthesis that was replaced was the interface, except in 2 cases. FINDINGS: Each DS-TF interface was fabricated, fit and delivered in a single clinic visit. At 6-months follow-up, 38 users reported an average of 29.8% increase in satisfaction with their new interface compared with original, and a 14.8% increase in satisfaction with the services they received from the clinic in providing of the new prosthesis vs. their original prosthesis. The main outcome increases were between baseline (initial fitting) and 6-week follow-up and remained consistent after 6 months. This improvement was consistent irrespective if the user needed a new socket for clinical reasons or not. CONCLUSION: This study shows that after a standardized training and implementation, the DS-TF fabrication process including a new interface improves the user’s satisfaction with their prosthetic device and services. Layman's Abstract The connection between an amputee’s remaining limb and their prosthesis is called the interface and is the most critical part in a prosthetic system for the user satisfaction, comfort and mobility. Interfaces commonly consist of two parts; a flexible “liner” rolled onto the limb, which then goes into a hard socket custom-made by the prosthetist. The assembled interface then provides a secure connection between the users remaining limb and the prosthesis. Historically the prosthetist’s fabrication and fitting procedure required many hours of time and multiple visits to the prosthetic clinic before the interface was delivered to the user. Direct Socket for above knee prosthetic users is a new method of fabricating laminated sockets directly on the residual limb that enables fabrication and delivery in a single visit. However, Direct Socket require different training and methods than what most prosthetists are familiar with. This new procedure was implemented in six different prosthetic clinics across the United States. Seven CP’s were trained, each in their clinic and the method was tested on 38 users for a period of 6 months. The users filled in questionnaires about their experience and satisfaction using their existing socket, as well as their satisfaction of using their new socket. Overall, the Direct Socket prosthetic users reported after the 6-months follow-up significantly greater (29.8%) satisfaction with their new socket compared to their previous socket. They also reported 14.8% increase in satisfaction with the services they obtained from the clinic when receiving the new socket, compared to their satisfaction with receiving their original socket. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/34672/26933 How To Cite: Marable W.R, Smith C, Sigurjónsson B.Þ, Atlason I.F, Johannesson G.A. Transfemoral socket fabrication method using direct casting: outcomes regarding patient satisfaction with device and services. Canadian Prosthetics & Orthotics Journal. 2020;Volume 3, Issue 2, No.6. https://doi.org/10.33137/cpoj.v3i2.34672 Corresponding Author: G. Anton Johannesson, PhDTeamOlmed, Kistagången 12, 164 40 Kista, Stockholm, Sweden.E-mail: ajohannesson@teamolmed.seORCID: https://orcid.org/0000-0001-8729-458X
BACKGROUND: Amputation at the transfemoral (TF) level reduces the rate of successful prosthetic fitting, functional outcome, and quality of life (QoL) compared with transtibial amputation. The TF socket interface is considered the most critical part of the prosthesis, but socket discomfort is still the most common user complaint. Direct Socket for transfemoral prosthesis users is a novel interface fabrication process where the socket is shaped and laminated directly on the residual limb and delivered in a single visit. OBJECTIVE(S): The aim of this study was to investigate if prosthetic users' quality of life (QoL), comfort, and mobility with a Direct Socket TF interface were comparable to their experience with their previous prostheses. METHODOLOGY: The pre/post design prospective cohort study included 47 subjects. From this cohort, 36 subjects completed the 6-months follow-up (mean age 58 years, 27 males). Outcomes at baseline included EQ-5D-5L®, PLUS-M™, CLASS, ABC, AMPPRO, and TUG. At 6-weeks and 6-months, subjects repeated all measures. Seven Certified Prosthetist (CP) investigators performed observations and data collection at six different sites (from July 2018 to April 2020). FINDINGS: Results showed significant improvement in all outcome measures for the 36 subjects that completed both 6-weeks and 6-months follow-ups. CLASS sub-scales showed significantly improved stability, suspension, comfort, and socket appearance. Improvement in K-Level and less use of assistive devices were observed with the AMPPRO instrument, indicating improved user mobility and performance. QoL was also increased, as measured in Quality-Adjusted-Life-Years (QALY) from the EQ-5D-5L. CONCLUSION: Evidence from the findings demonstrate that the Direct Socket TF system and procedure can be a good alternative to the traditional method of prosthetic interface delivery. Layman's Abstract After lower limb amputation, the goal for most people is to regain mobility and independence and return to normal daily activities. Typically, people with transfemoral amputation are less likely to receive a prosthesis or fully use a prosthesis as compared to people with transtibial amputation. Moreover, their quality of life is also lower. The Direct Socket TF method is a new way of fabricating a prosthetic socket for users with above-knee amputation, enabling fabrication directly onto the residual limb and delivery of the socket in a single visit. In this study, we wanted to understand how the effect of Direct Socket TF on prosthetic 'user's quality of life, health, mobility level, and balance would compare to their previous prosthesis. This new Direct Socket TF procedure was implemented in six different prosthetic clinics across the United States and used by 36 prosthetic users for six months. Our first article on this study describes increased user satisfaction with their new interface and the single visit service model. This second article on the same clinical investigation documents the significant improvement in outcomes compared to their original interface in terms of quality of life, confidence, mobility, comfort, stability, and activity level. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/36065/27923 Direct Socket TF – Summary (YouTube): https://www.youtube.com/watch?v=-fvVFqjgxjo How To Cite: Walker J, Marable W.R, Smith C, Sigurjónsson B.Þ, Atlason I.F, Johannesson G.A. Clinical outcome of transfemoral direct socket interface (part 2). Canadian Prosthetics & Orthotics Journal. 2021;Volume 4, Issue 1, No.6. https://doi.org/10.33137/cpoj.v4i1.36065 Corresponding Author: Anton Johannesson, PhDTeamOlmed, Kistagången 12, 164 40 Kista, Stockholm, Sweden.E-mail: ajohannesson@teamolmed.seORCID: https://orcid.org/0000-0001-8729-458X
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