scholarly journals Evaluation of Treatment for Volumetric Muscle Loss in a Porcine Tibia Segmental Bone Defect Model

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Nicklaus Diggins ◽  
Seungyup Sun ◽  
Benjamin T. Corona ◽  
Aamir Tucker ◽  
Alex Brinker ◽  
...  

Background and Hypothesis: Injury to soft tissue with volumetric muscle loss (VML) concomitant to segmental bone defects (SBDs) can be difficult to treat. One potential option is skeletal muscle autograft (SMA). We hypothesize the maximal torque measured in vivo and Radiographic Union Scale for Tibial Fractures (RUST) scores will be increased in the VML+SBD+SMA group compared to the VML+SBD group, but will be decreased compared to SBD alone. Experimental Design or Project Methods: 18 male, Yucatan minipigs aged 1821 months were randomized into 3 groups: VML+SBD+SMA, VML+SBD, and SBD. This study is still ongoing with 12 pigs having had the surgery performed to date. In vivo muscle testing was performed prior to surgery in both hindlimbs to assess baseline strength. RUST scores and in vivo muscle testing was/will be performed at 1, 2, and 3 months post-injury. All procedures were conducted following approved IACUC protocol. Results: Muscle testing results demonstrate no significant difference between control and operative limbs pre-surgery (T-tests, p= 0.673, 0.824, and 0.739 for VML+SBD+SMA, VML+SBD and SBD groups, respectively), or between the 3 different groups pre- or post-surgery (2-way ANOVA, p=0.788). The average RUST score for each treatment group at 2 months was 6.8±2.2, 7.7 7.7±1.1, and 8.6 8.6±0.4 for VML+SBD+SMA (n=2), VML+SBD (n=5), and SBD (n=3) groups, respectively. Conclusion and Potential Impact: The lack of difference amongst groups on pre-operative muscle testing and a difference post-operatively between control and operative legs post-operatively help to validate this study. Preliminary results demonstrate a reduced RUST score for the VML+SBD+SMA group; however, this along with the lack of difference found in muscle testing results postoperatively may be an artifact due to small sample size and/or timing. Development of a model for VML and SBD will allow for testing of therapies for treat clinical problems.

2021 ◽  
Author(s):  
Gianna Spitta ◽  
Lena Fliedner ◽  
Tobias Gleich ◽  
Tristan Zindler ◽  
Miriam Sebold ◽  
...  

The association between blunted dopaminergic neurotransmission and alcohol use disorder (AUD) is well-known. In particular, the impairment of postsynaptic dopamine 2 and 3 receptors (DRD2/3) in the ventral and dorsal striatum during the development and maintenance of alcohol addiction has been investigated in several positron emission tomography (PET) studies. However, it is unclear whether these changes are the result of adaptation or genetic predisposition. Here we investigated the association between DRD2/ankyrin repeat and kinase domain-containing 1 (ANKK1) TaqIA allele (rs1800497) status and striatal DRD2/3 availability measured by 18F-fallypride PET in 13 AUD patients and 17 sex-matched healthy controls. Age and smoking status were included as covariates. Contrary to our expectations, TaqIA allele status was not associated with striatal DRD2/3 availability in either group and there was no significant difference between groups, possibly due to the relatively small sample size (N=30). Nonetheless, this is the first in vivo study investigating the relationship between dopamine receptor availability and genetic factors in AUD. The pitfalls of assessing such relationships in a relatively small sample are discussed.


Author(s):  
Conly L. Rieder ◽  
S. Bowser ◽  
R. Nowogrodzki ◽  
K. Ross ◽  
G. Sluder

Eggs have long been a favorite material for studying the mechanism of karyokinesis in-vivo and in-vitro. They can be obtained in great numbers and, when fertilized, divide synchronously over many cell cycles. However, they are not considered to be a practical system for ultrastructural studies on the mitotic apparatus (MA) for several reasons, the most obvious of which is that sectioning them is a formidable task: over 1000 ultra-thin sections need to be cut from a single 80-100 μm diameter egg and of these sections only a small percentage will contain the area or structure of interest. Thus it is difficult and time consuming to obtain reliable ultrastructural data concerning the MA of eggs; and when it is obtained it is necessarily based on a small sample size.We have recently developed a procedure which will facilitate many studies concerned with the ultrastructure of the MA in eggs. It is based on the availability of biological HVEM's and on the observation that 0.25 μm thick serial sections can be screened at high resolution for content (after mounting on slot grids and staining with uranyl and lead) by phase contrast light microscopy (LM; Figs 1-2).


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Abhishek Kumar ◽  
Minati Choudhury ◽  
Sakshi Dhingra Batra ◽  
Kriti Sikri ◽  
Anushree Gupta

Abstract Objective Endothelin-1 plays an important role in the pathogenesis of severe pulmonary hypertension. The + 139 ‘A’, adenine insertion variant in 5′UTR of edn1 gene has been reported to be associated with increased expression of Endothelin-1 in vitro. The aim of present study was to explore the association of this variant with the circulating levels of Endothelin-1 in vivo using archived DNA and plasma samples from 38 paediatric congenital heart disease (cyanotic and acyanotic) patients with severe pulmonary hypertension. Results The plasma Endothelin-1 levels were highly varied ranging from 1.63 to75.16 pg/ml. The + 139 ‘A’ insertion variant in 5′UTR of edn1 was seen in 8 out of 38 cases with only one acyanotic sample demonstrating homozygosity of inserted ‘A’ allele at + 139 site (4A/4A genotype). The plasma Endothelin-1 levels in children with homozygous variant 3A/3A genotype were comparable in cyanotic and acyanotic groups. Lone 4A/4A acyanotic sample had ET-1 levels similar to the median value of ET-1 associated with 3A/3A genotype and was absent in cyanotic group presumably due to deleterious higher ET-1 levels. The discussed observations, limited by the small sample size, are suggestive of homozygous adenine insertion variant posing a risk in cyanotic babies with Severe Pulmonary Hypertension.


2020 ◽  
Vol 2 (Supplement_3) ◽  
pp. ii14-ii14
Author(s):  
Takaaki Beppu ◽  
Yuichi Sato ◽  
Toshiaki Sasaki ◽  
Kazunori Terasaki ◽  
Kuniaki Ogasawara

Abstract Background: The aim was to clarify whether positron emission tomography with 11C-methyl-L-methionine (met-PET) is useful to decide on discontinuation of TMZ-adjuvant therapy in patients with residual diffuse astrocytic tumor. Methods: Subjects were 44 patients with residual tumor comprising 17 with IDH1-mutant diffuse astrocytoma (DA), 13 with IDH1-mutant anaplastic astrocytoma (AA), and 14 with IDH1-wild glioblastoma (GB). All patients received TMZ-adjuvant chemotherapy (median, 12 courses), and whether to discontinue or continue TMZ-adjuvant chemotherapy was decided on the basis of the tumor-to-normal ratio in standardized uptake value from met-PET (T/N); patients with T/N < 1.6 immediately discontinued TMZ, and patients with T/N > 1.6 were either to continued or discontinued TMZ. Progression-free survival (PFS) was compared between patients with T/N > 1.6 and T/N < 1.6 in each tumor type. Median observation period was 434 days after met-PET scanning. Results: The number of patient who underwent recurrence was 10 in DA, 7 in AA, and 11 in GB. All patients showing T/N > 1.6 underwent tumor recurrence. PFS was significantly longer in patients with T/N < 1.6 than T/N > 1.6 in DA and AA (p < 0.01 in both types), but was no significant difference between 2 groups in GB (p = 0.06). Sixteen of 17 patients (94%) in DA and AA showed recurrence from residual tumor, whereas 4 of 11 patients (36%) in GB showed recurrent tumor at remote regions which were different from residual tumor. Conclusions: The present study suggested that met-PET is beneficial to decide to discontinue adjuvant chemotherapy with TMZ in patients with residual tumors of DA and AA, but not useful for patients with GB. Reasons for unsuccessful results in GB might have been small sample size, failure of establishing the cut off value in T/N, recurrences at remote regions where not be assessed by met-PET.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S799-S800
Author(s):  
Nerea Irusta ◽  
Ana Vega ◽  
Yoichiro Natori ◽  
Lilian M Abbo ◽  
Lilian M Abbo ◽  
...  

Abstract Background In-vitro studies have shown synergistic bactericidal activity with daptomycin (DAP) plus β-lactam antimicrobials against vancomycin resistant enterococci (VRE). There is a paucity of data regarding clinical outcomes with this combination in VRE bloodstream infections (BSI). The purpose of this study was to assess the efficacy of DAP plus a β-lactam with in-vitro activity vs. other therapies for treatment of VRE BSI. Methods IRB-approved, single-center, retrospective study of patients with VRE BSI from 01/2018-09/2019. Patients were excluded if < 18 years old, pregnant, or incarcerated. The primary outcome was time-to-microbiological clearance. Secondary outcomes included infection-related mortality, 30-day all-cause mortality, and incidence of recurrent BSI within 30 days of index culture. Targeted DAP doses were ≥ 8mg/kg and based on MIC. Factors associated with significance for outcomes, via univariate analysis, were evaluated with multivariable logistic regression (MLR), removed in a backward-step approach. Results A total of 85 patients were included, 23 of which received DAP plus a β-lactam. The comparator arm included linezolid or DAP monotherapy. Patients with combination therapy had significantly higher Charlson Comorbidity Index (CCI) (p=0.013) and numerically higher Pitt Bacteremia scores (PBS) (p=0.087) (Table 1). There was no difference seen in the primary outcome (Table 2). Secondary outcomes are provided in Table 2. The presence of polymicrobial infection and higher PBS were significantly associated with infection-related mortality (p=0.008 and p=0.005, respectively) by MLR. A Mann Whitney U test indicated that presence of infection-related mortality was greater for patients with higher MICS (U=20.5, p=0.06). The presence of an underlying source may be related to recurrence of BSI (p=0.075). Table 1: Patient Characteristics Table 2. Primary and Secondary Outcomes Conclusion We did not find a significant difference in time-to-microbiological clearance, although patients treated with DAP and a β-lactam had higher CCI and PBS. These results are limited by retrospective design, small sample size, and potential selection bias. Prospective randomized studies are needed to further validate these findings. Disclosures All Authors: No reported disclosures


2021 ◽  
Vol 8 ◽  
pp. 205435812110293
Author(s):  
Danielle E. Fox ◽  
Robert R. Quinn ◽  
Paul E. Ronksley ◽  
Tyrone G. Harrison ◽  
Hude Quan ◽  
...  

Background: Simultaneous kidney-pancreas transplantation (SPK) has benefits for patients with kidney failure and type I diabetes mellitus, but is associated with greater perioperative risk compared with kidney-alone transplantation. Postoperative care settings for SPK recipients vary across Canada and may have implications for patient outcomes and hospital resource use. Objective: To compare outcomes following SPK transplantation between patients receiving postoperative care in the intensive care unit (ICU) compared with the ward. Design: Retrospective cohort study using administrative health data. Setting: In Alberta, the 2 transplant centers (Calgary and Edmonton) have different protocols for routine postoperative care of SPK recipients. In Edmonton, SPK recipients are routinely transferred to the ICU, whereas in Calgary, SPK recipients are transferred to the ward. Patients: 129 adult SPK recipients (2002-2019). Measurements: Data from the Canadian Institute for Health Information Discharge Abstract Database (CIHI-DAD) were used to identify SPK recipients (procedure codes) and the outcomes of inpatient mortality, length of initial hospital stay (LOS), and the occurrence of 16 different patient safety indicators (PSIs). Methods: We followed SPK recipients from the admission date of their transplant hospitalization until the first of hospital discharge or death. Unadjusted quantile regression was used to determine differences in LOS, and age- and sex-adjusted marginal probabilities were used to determine differences in PSIs between centers. Results: There were no perioperative deaths and no major differences in the demographic characteristics between the centers. The majority of the SPK transplants were performed in Edmonton (n = 82, 64%). All SPK recipients in Edmonton were admitted to the ICU postoperatively, compared with only 11% in Calgary. There was no statistically significant difference in the LOS or probability of a PSI between the 2 centers (LOS for Edmonton vs Calgary:16 vs 13 days, P = .12; PSIs for Edmonton vs Calgary: 60%, 95% confidence interval [CI] = 0.50-0.71 vs 44%, 95% CI = 0.29-0.59, P = .08). Limitations: This study was conducted using administrative data and is limited by variable availability. The small sample size limited precision of estimated differences between type of postoperative care. Conclusions: Following SPK transplantation, we found no difference in inpatient outcomes for recipients who received routine postoperative ICU care compared with ward care. Further research using larger data sets and interventional study designs is needed to better understand the implications of postoperative care settings on patient outcomes and health care resource utilization.


Author(s):  
Li Wang ◽  
Yiwen Zhang ◽  
Jiajun Zhong ◽  
Yuan Zhang ◽  
Shuisheng Zhou ◽  
...  

Objective: The efficacy of mesenchymal stem cell (MSC) therapy in acetaminophen-induced liver injury has been investigated in animal experiments, but individual studies with a small sample size cannot be used to draw a clear conclusion. Therefore, we conducted a systematic review and meta-analysis of preclinical studies to explore the potential of using MSCs in acetaminophen-induced liver injury. Methods: Eight databases were searched for studies reporting the effects of MSCs on acetaminophen hepatoxicity. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were used. SYRCLE’s risk of bias tool for animal studies was applied to assess the methodological quality. A meta-analysis was performed by using RevMan 5.4 and STATA/SE 16.0 software. Results: Eleven studies involving 159 animals were included according to PRISMA statement guidelines. Significant associations were found for MSCs with the levels of alanine transaminase (ALT) (standardized mean difference (SMD) − 2.58, p < 0.0001), aspartate aminotransferase (AST) (SMD − 1.75, p = 0.001), glutathione (GSH) (SMD 3.7, p < 0.0001), superoxide dismutase (SOD) (SMD 1.86, p = 0.022), interleukin 10 (IL-10) (SMD 5.14, p = 0.0002) and tumor necrosis factor-α (TNF-α) (SMD − 4.48, p = 0.011) compared with those in the control group. The subgroup analysis showed that the tissue source of MSCs significantly affected the therapeutic efficacy (p < 0.05). Conclusion: Our meta-analysis results demonstrate that MSCs could be a potential treatment for acetaminophen-related liver injury.


2021 ◽  
Author(s):  
Yasamin A. Jodat ◽  
Ting Zhang ◽  
Ziad Al Tanoury ◽  
Tom Kamperman ◽  
Kun Shi ◽  
...  

Abstract Engineering of biomimetic tissue implants provides an opportunity for repairing volumetric muscle loss (VML), beyond a tissue’s innate repair capacity. Here, we present thick, suturable, and pre-vascularized 3D muscle implants containing human induced pluripotent stem cell-derived myogenic precursor cells (hiPSC-MPCs), which can differentiate into skeletal muscle cells while maintaining a self-renewing pool. The formation of contractile myotubes and millimeter-long fibers from hiPSC-MPCs is achieved in chemically, mechanically, and structurally tailored extracellular matrix-based hydrogels, which can serve as scaffolds to ultimately organize the linear fusion of myoblasts. Embedded multi-material bioprinting is used to deposit complex patterns of perfusable vasculatures and aligned hiPSC-MPC channels within an endomysium-like supporting gel to recapitulate muscle architectural integrity in a facile yet highly rapid manner. Moreover, we demonstrate successful graft-host integration and de novo muscle formation upon in vivo implantation of pre-vascularized constructs within a VML model. This work pioneers the engineering of large pre-vascularized hiPSC-derived muscle tissues toward next generation VML regenerative therapies.


2019 ◽  
Vol 10 (7) ◽  
pp. 871-874 ◽  
Author(s):  
Jeffrey C. Wang ◽  
S. Tim Yoon ◽  
Darrel S. Brodke ◽  
Jong-Beom Park ◽  
Patrick Hsieh ◽  
...  

Study Design: Classification development. Objectives: The aim of our study was to develop a 3-tier classification for the levels of evidence for osteobiologics and provide a description of the principles by which osteobiologics can be evaluated. BOnE (Bone Osteobiologics and Evidence) classification evaluates each osteobiologic based on the available evidence, and if the published evidence is based on clinical, in vivo or in vitro studies. Methods: The process of establishing the BOnE classification included 5 face-to-face meetings and 2 web calls among members of the AOSpine Knowledge Forum Degenerative. Results: The 3 levels of evidence were determined based on the type of data on osteobiologics: level A for human studies, level B for animal studies, and level C for in vitro studies, with level A being the highest level of evidence. Each level was organized into 4 subgroups (eg, A1, A2, A3, and A4). Conclusions: The use and the variety of osteobiologics for spine fusion has dramatically increased over the past few decades; however, literature on their effectiveness is inconclusive. Several prior systematic reviews developed by AOSpine Knowledge Forum Degenerative reported low level of evidence primarily due to the high risk of bias, small sample size, lack of control groups, and limited patient-reported outcomes. BOnE classification will provide a universal platform for research studies and journal publications to classify a new or an existing product and will allow for creating decision-making algorithms for surgical planning.


2020 ◽  
Vol 4 (9) ◽  
pp. 2731-2743
Author(s):  
Yang Gao ◽  
Tianxu Zhang ◽  
Junyao Zhu ◽  
Dexuan Xiao ◽  
Mei Zhang ◽  
...  

The challenges associated with muscle degenerative diseases and volumetric muscle loss (VML) emphasizes the prospects of muscle tissue regeneration.


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