Buccal mucosal graft urethroplasty in male cats with traumatic complete urethral rupture

OBJECTIVE To evaluate the feasibility of buccal mucosal graft urethroplasty for repairing complete urethral rupture in cats. ANIMALS 15 male domestic shorthair cats with traumatic complete urethral rupture. PROCEDURES In each cat, a section of buccal mucosa was harvested, sutured, and formed into a tubule by use of an 8F indwelling catheter as support. This tubular graft was connected to both ruptured ends of the urethra to renew the urinary passage. The catheter was left in place until the absence of leakage was confirmed by positive contrast retrograde urethrography. After spontaneous urination was confirmed, cats were discharged from the hospital. Six months later, urethrography was repeated and owners were asked to score their cats’ urinary function and quality of life. RESULTS 13 cats recovered well following surgery, with no complications in the oral cavity or surgical site and no signs of difficulty or discomfort when urinating. Urethrography 2 weeks and 6 months after surgery revealed no stricture or leakage in the abdominal cavity. The 2 remaining cats developed a urethral stricture and underwent second surgery with a successful outcome. At the 6-month follow-up, 14 cats had only mild urinary signs, and 1 cat had incontinency. Owners indicated they were delighted (n = 14) or pleased (1) with their cats’ quality of life. CLINICAL RELEVANCE Buccal mucosa was found to be a good source of graft tissue for performance of urethroplasty in male cats, yielding satisfactory outcomes with few postoperative complications. The described technique may be suitable for severe and complicated cases of urethral rupture in male cats.

A Novel Model for Encephalomyosynangiosis Surgery after Middle Cerebral Artery Occlusion-Induced Stroke in Mice

Background and Purpose: No effective treatment is available for most patients who suffer ischemic stroke. Development of novel treatment options is imperative. The brain attempts to self-heal after ischemic stroke via various mechanism mediated by restored blood circulation in affected region of brain but this process is limited by inadequate angiogenesis or neoangiogenesis. Encephalomyosynangiosis (EMS) is a neurosurgical procedure that achieves angiogenesis with low morbidity in patients with moyamoya disease, reducing risk of stroke. However, EMS, surgery has never been studied as an therapeutic option after ischemic stroke. Here we described a novel procedure and feasibility data for EMS after ischemic stroke in mice. Methods: A 60 mins of middle cerebral artery occlusion (MCAo) was used to induce ischemic stroke in mice. After 3-4 hours of MCAo onset/sham, EMS was performed. Mortality of EMS, MCAo and. MCAo+EMS mice was recorded up to 21 days after surgery. Graft tissue viability was measured using a nicotinamide adenine dinucleotide reduced tetrazolium reductase assay. Results: EMS surgery after ischemic stroke does not increase mortality compared to stroke alone. Graft muscle tissue remained viable 21 days after surgery. Conclusions: This novel protocol is effective and well-tolerated, may serve as novel platform for new angiogenesis and thus recovery after ischemic stroke. If successful in mice, EMS can a very feasible and novel treatment option for ischemic stroke in humans.

Heterogeneity and neurovascular integration of intraportally transplanted islets revealed by 3-D mouse liver histology

Background: Intraportal islet transplantation has been clinically applied for treatment of unstable type 1 diabetes. However, in the liver, systematic assessment of the dispersed islet grafts and the graft-hepatic integration remains difficult, even in animal models. This is due to the lack of global and in-depth analyses of the transplanted islets and their microenvironment. Here, we apply 3-dimensional (3-D) mouse liver histology to investigate the islet graft microstructure, vasculature, and innervation. Methods: Streptozotocin-induced diabetic mice were used in syngeneic intraportal islet transplantation to achieve euglycemia. Optically cleared livers were prepared to enable 3-D morphological and quantitative analyses of the engrafted islets. Results: 3-D image data reveal the clot- and plaque-like islet grafts in the liver: the former are derived from islet emboli and associated with ischemia, whereas the latter (minority) resemble the plaques on the walls of portal vessels (e.g., at the bifurcation) with mild, if any, peri-graft tissue damage. Three weeks after transplantation, both types of grafts are revascularized, yet significantly more lymphatics are associated with the plaque- than clot-like grafts. Regarding the islet reinnervation, both types of grafts connect to the peri-portal nerve plexus and develop peri- and intra-graft innervation. Specifically, the sympathetic axons and varicosities contact the α-cells, highlighting the graft-host neural integration. Conclusion/interpretation: We present the heterogeneity of the intraportally transplanted islets and the graft-host neurovascular integration in mice. Our work provides the technical and morphological foundation for future high-definitional 3-D tissue and cellular analyses of human islet grafts in the liver.

Vitrification of particulated articular cartilage via calculated protocols

Preserving viable articular cartilage is a promising approach to address the shortage of graft tissue and enable the clinical repair of articular cartilage defects in articulating joints, such as the knee, ankle, and hip. In this study, we developed two 2-step, dual-temperature, multicryoprotectant loading protocols to cryopreserve particulated articular cartilage (cubes ~1 mm3 in size) using a mathematical approach, and we experimentally measured chondrocyte viability, metabolic activity, cell migration, and matrix productivity after implementing the designed loading protocols, vitrification, and warming. We demonstrated that porcine and human articular cartilage cubes can be successfully vitrified and rewarmed, maintaining high cell viability and excellent cellular function. The vitrified particulated articular cartilage was stored for a period of 6 months with no significant deterioration in chondrocyte viability and functionality. Our approach enables high-quality long-term storage of viable articular cartilage that can alleviate the shortage of grafts for use in clinically repairing articular cartilage defects.

Type IV pilus retraction enables sustained bacteremia and plays a key role in the outcome of meningococcal sepsis in a humanized mouse model

Neisseria meningitidis (the meningococcus) remains a major cause of bacterial meningitis and fatal sepsis. This commensal bacterium of the human nasopharynx can cause invasive diseases when it leaves its niche and reaches the bloodstream. Blood-borne meningococci have the ability to adhere to human endothelial cells and rapidly colonize microvessels. This crucial step enables dissemination into tissues and promotes deregulated inflammation and coagulation, leading to extensive necrotic purpura in the most severe cases. Adhesion to blood vessels relies on type IV pili (TFP). These long filamentous structures are highly dynamic as they can rapidly elongate and retract by the antagonistic action of two ATPases, PilF and PilT. However, the consequences of TFP dynamics on the pathophysiology and the outcome of meningococcal sepsis in vivo have been poorly studied. Here, we show that human graft microvessels are replicative niches for meningococci, that seed the bloodstream and promote sustained bacteremia and lethality in a humanized mouse model. Intriguingly, although pilus-retraction deficient N. meningitidis strain (ΔpilT) efficiently colonizes human graft tissue, this mutant did not promote sustained bacteremia nor induce mouse lethality. This effect was not due to a decreased inflammatory response, nor defects in bacterial clearance by the innate immune system. Rather, TFP-retraction was necessary to promote the release of TFP-dependent contacts between bacteria and, in turn, the detachment from colonized microvessels. The resulting sustained bacteremia was directly correlated with lethality. Altogether, these results demonstrate that pilus retraction plays a key role in the occurrence and outcome of meningococcal sepsis by supporting sustained bacteremia. These findings open new perspectives on the role of circulating bacteria in the pathological alterations leading to lethal sepsis.

Autologous Neurosensory Retinal Transplantation: A Report of Three Cases

Purpose: To present the anatomical and functional outcomes of autologous surgical transplantation of a free neurosensory retinal graft in three cases of recurrent and chronic full thickness macular hole (MH). Method: A retrospective case series, reporting the profile, preoperative presentation, surgical technique, and postoperative outcome of three consecutive eyes of three patients who had autologous retina transplantation (ART) surgery for recurrent and chronic MHs, and had a minimum of six months follow-up. The technique involved excision of a free neurosensory graft after laser demarcation of the harvest site. The graft was slid under perfluorocarbon liquid (PFCL) into the MH. A five-day tamponade with PFCL was used to secure the graft within the MH and then exchanged with air. Results: The patients were one female and two males aged 60, 44, and 67 years, respectively. All eyes had a successful surgery. Postoperative vision improved from 6/36 to 6/18 in patient 1 and remained the same as a preoperative vision in the other two eyes. No eye lost vision postoperatively. The main complication of surgery was the occurrence of retinal and vitreous hemorrhage in one eye (this did not appear to jeopardize the outcome) and retraction of graft tissue in two eyes. Conclusion: ART appears to be a safe and effective treatment for difficult MHs. Our results are comparable to previous studies. Short-term use of PFCL can be useful to secure the graft within the MH. Methods of improving visual function should be the focus of further research in this promising area.

10 Graft Infections

Ligament reconstructions are one of the most frequently performed orthopaedic procedures. Postoperative graft infection, although a rare complication, is one of the most serious complications of ligament reconstructions. Graft infections represent a uniquely challenging situation with the goal of maintaining joint stability while eradicating the infectious process. Intra-articular infections occur following 0.05 to 1.9% of anterior cruciate ligament (ACL) reconstructions and 0.5% of posterior cruciate ligament (PCL) reconstructions, and gram-positive bacteria are typically responsible for infection. Patients typically present with signs and symptoms of septic arthritis during the acute (<2 weeks) period postoperatively, but graft infections have been reported for up to 15 months after ACL reconstructions. Risks for infection following ACL reconstruction include hamstring autograft usage, prior knee surgery, and hemarthrosis. Graft infections typically require multiple surgical debridements and prolonged antibiotic management, adding to the overall healthcare cost. Non-operative and operative measures that preserve the graft tissue have been successful, but removal of the graft and subsequent reimplantation are sometimes necessary. Additionally, the situation of intraoperative graft contamination during ACL reconstruction is discussed and whether a contaminated graft can be safely implanted. This chapter reviews multiple aspects of graft infections including demographics, risk factors, diagnosis, management, complications, and prevention.

Circulating miRNA in Patients Undergoing Total Pancreatectomy and Islet Autotransplantation

Circulating microRNAs (miRNAs) can be biomarkers for diagnosis and progression of several pathophysiological conditions. In a cohort undergoing total pancreatectomy with islet autotransplantation (TPIAT) from the multicenter Prospective Observational Study of TPIAT (POST), we investigated associations between a panel of circulating miRNAs (hsa-miR-375, hsa-miR-29b-3p, hsa-miR-148a-3p, hsa-miR-216a-5p, hsa-miR-320d, hsa-miR-200c, hsa-miR-125b, hsa-miR-7-5p, hsa-miR-221-3p, hsa-miR-122-5p) and patient, disease and islet-isolation characteristics. Plasma samples ( n = 139) were collected before TPIAT and miRNA levels were measured by RTPCR. Disease duration, prior surgery, and pre-surgical diabetes were not associated with circulating miRNAs. Levels of hsa-miR-29b-3p ( P = 0.03), hsa-miR-148a-3p ( P = 0.04) and hsa-miR-221-3p ( P = 0.01) were lower in those with genetic risk factors. Levels of hsa-miR-148a-3p ( P = 0.04) and hsa-miR-7-5p ( P = 0.04) were elevated in toxic/metabolic disease. Participants with exocrine insufficiency had lower hsa-miR-29b-3p, hsa-miR-148a-3p, hsa-miR-320d, hsa-miR-221-3p ( P < 0.01) and hsa-miR-375, hsa-miR-200c-3p, and hsa-miR-125b-5p ( P < 0.05). Four miRNAs were associated with fasting C-peptide before TPIAT (hsa-miR-29b-3p, r = 0.18; hsa-miR-148a-3p, r = 0.21; hsa-miR-320d, r = 0.19; and hsa-miR-221-3p, r = 0.21; all P < 0.05), while hsa-miR-29b-3p was inversely associated with post-isolation islet equivalents/kg and islet number/kg ( r = −0.20, P = 0.02). Also, hsa-miR-200c ( r = 0.18, P = 0.03) and hsa-miR-221-3p ( r = 0.19, P = 0.03) were associated with islet graft tissue volume. Further investigation is needed to determine the predictive potential of these miRNAs for assessing islet autotransplant outcomes.

An in vitro grafting method to quantify mechanical forces of adhering tissues

AbstractsGrafting is an indispensable agricultural technology for propagating useful tree varieties and obtaining beneficial traits of two varieties/species—as stock and scion—at the same time. Recent studies of molecular events during grafting have revealed dynamic physiological and transcriptomic changes. Strategies focused on specific grafting steps are needed to further associate each physiological and molecular event with those steps. In this study, we developed a method to investigate the tissue adhesion event, an early grafting step, by improving an artificial in vitro grafting system in which two pieces of 1.5-mm thick Nicotiana benthamiana cut stem sections were combined and cultured on medium. We prepared a silicone sheet containing five special cutouts for adhesion of cut stem slices. We quantitatively measured the adhesive force at these grafting interfaces using a force gauge and found that graft adhesion started 2 days after grafting, with the adhesive force gradually increasing over time. After confirming the positive effect of auxin on grafting by this method, we tested the effect of cellulase treatment and observed significant enhancement of graft tissue adhesion. Compared with the addition of auxin or cellulase individually, the adhesive force was stronger when both auxin and cellulase were added simultaneously. The in vitro grafting method developed in this study is thus useful for examining the process of graft adhesion.