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The worldwide pandemic outbreak due to severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has created unprecedented challenges for public health services. Lombardy, region of the Northern Italy, has been the first area in the Western world whose organs and tissues procurement programs have had to face the virus pandemic emergency. We retrospectively collected and analyzed data about cardiovascular tissues (CT) in 2019 and in 2020. We aimed to describe the rapid evolution of SARS-CoV-2 regulation laws for tissue donor’s selection and harvesting from February 2020 until January 2021. As expected the number of CT donors in 2020 was significantly lower than those of 2019 (66 vs. 99, p value 0.02). The total number of CT collected from donors have been 254 in 2019 and 206 in 2020 (p 0.28). Femoral arteries were the most required vascular tissues (55.5% in 2019 and 40% in 2020). Fifty-five and forty-eight pulmonary valves were implanted in 2019 and 2020, respectively. No differences were found for the types of CT requests between the 2 years. The median age of receivers of vascular tissues was 69.6 ± 14.6 years in the 2019 and 63.3 ± 14.9 years in 2020 (p

Purpose The purpose of this study was to report trends in the prevalence of early graft failure after endothelial keratoplasty in the United States. Methods Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK) graft volumes were collected from records maintained by 6 major eye banks in the United States from January 1, 2013, to December 31, 2018. The prevalence and presumed cause of early graft failures (defined as a graft with persistent edema or regrafted within 8 weeks after keratoplasty) each year were sourced from surgeon-reported adverse events. Failed graft cases from the 3 eye banks were compared with nonfailures at the donor and recipient levels to perform subset analysis of factors associated with early graft failure. Results A total of 51,887 endothelial keratoplasty tissues were distributed during the study period; 72% were DSAEK grafts. The total number of early graft failures reported was 168 of 14,284 (1.18%) for DMEK and 322 of 37,603 (0.86%) for DSAEK. Early DMEK failures decreased from 2013 (7.69%) to 2018 (0.68%). In generalized linear mixed model analyses adjusting for donor tissue characteristics, recipient age, and diagnosis, an association of borderline significance was found between higher donor age and early failure [odds ratio (95% confidence interval): 1.03 (1.00-1.05); unit change of 1 yr] and DSAEK [odds ratio 1.02 (1.00-1.04); unit of change 1 yr] cases. Conclusions The proportion of early graft failures in DMEK decreased over time and was comparable with failure rates in DSAEK at the end of the study period. The surgical learning curve might have played a role.

The use of bulk nanobubbles in biomedicine is increasing in recent years, which is attributable to the array of therapeutic and diagnostic tools promised by developing bulk nanobubble technologies. From cancer drug delivery and ultrasound contrast enhancement to malaria detection and the diagnosis of acute donor tissue rejection, the potential applications of bulk nanobubbles are broad and diverse. Developing these technologies to the point of clinical use may significantly impact the quality of patient care. This review compiles and summarizes a representative collection of the current applications, fabrication techniques, and characterization methods of bulk nanobubbles in biomedicine. Current state-of-the-art generation methods are not designed to create nanobubbles of high concentration and low polydispersity, both characteristics of which are important for several bulk nanobubble applications. To date, microfluidics has not been widely considered as a tool for generating nanobubbles, even though the small-scale precision and real-time control offered by microfluidics may overcome the challenges mentioned above. We suggest possible uses of microfluidics for improving the quality of bulk nanobubble populations and propose ways of leveraging existing microfluidic technologies, such as organ-on-a-chip platforms, to expand the experimental toolbox of researchers working to develop biomedical nanobubbles.

Endothelial keratoplasty has revolutionized the treatment of corneal endothelial dysfunction and lowered the threshold for treatment by providing rapid visual rehabilitation and setting a high standard for safety and efficacy. Over time, endothelial keratoplasty techniques have evolved toward the use of thinner tissue to optimize visual outcomes; refinements have facilitated donor tissue preparation, handling, and attachment; and adaptations have expanded utilization in eyes with challenging ocular anatomy. Despite early concerns about graft longevity, emerging 10-year endothelial cell loss and graft survival data have been encouraging. A shortage of human donor corneas restricts utilization in many areas of the world and is driving a search for keratoplasty alternatives. Further work is needed to expand the donor supply, minimize impediments to adoption, optimize graft survival, and improve refractive predictability.

Purpose To describe the risk factors, management, and outcome of delayed Descemet membrane (DM) detachment after penetrating keratoplasty (PK) for keratoconus. Methods We report 7 eyes from 6 cases and combine these data with 7 previous case reports identified by a search of PubMed. Results DM detachment occurred at a median of 25 years (range, 7-33 years) after PK. One individual had bilateral detachments. There was typically a mild ocular discomfort accompanied in some cases by a rapid onset of visual blur. Cases were often treated for allograft rejection before a DM detachment was suspected and confirmed by optical coherence tomography. Detachments were limited to the donor tissue in 11 eyes, but a DM break was identified at the time of onset in only 4 eyes. Thinning of the host corneal rim with ectasia was reported in 8 eyes (57%). In 3 eyes, the detachment resolved spontaneously, but in 2 eyes, a detachment was still present at 12 months. Gas tamponade to reattach the DM was performed in 9 eyes and was effective in 4 eyes. Five eyes underwent a repeat PK or endothelial keratoplasty. Histology showed fibroblastic proliferation on the stromal surface of the folded DM. Conclusions The cause for DM detachment many years after PK is unknown, although progressive thinning of the host cornea and secondary graft ectasia may be implicated. Gas tamponade can be effective, but a repeat keratoplasty might be necessary. DM detachment should be included in the differential diagnosis for late-onset corneal edema after PK.

In recent decades, cell biology has made rapid progress. Cell isolation and cultivation techniques, supported by modern laboratory procedures and experimental capabilities, provide a wide range of opportunities for in vitro research to study physiological and pathophysiological processes in health and disease. They can also be used very efficiently for the analysis of biomaterials. Before a new biomaterial is ready for implantation into tissues and widespread use in clinical practice, it must be extensively tested. Experimental cell models, which are a suitable testing ground and the first line of empirical exploration of new biomaterials, must contain suitable cells that form the basis of biomaterial testing. To isolate a stable and suitable cell culture, many steps are required. The first and one of the most important steps is the collection of donor tissue, usually during a surgical procedure. Thus, the collection is the foundation for the success of cell isolation. This article explains the sources and neurosurgical procedures for obtaining brain tissue samples for cell isolation techniques, which are essential for biomaterial testing procedures.

This article highlights the need for skin donations to treat burn wounds. South Africa has an exceptionally high number of burn wound victims per annum. The ideal way to treat burn wounds is to transplant skin from another part of the patient’s body to the affected areas (autografts). Unfortunately, this is not always possible or feasible and in those cases skin from cadavers (allografts) should be used, but this can only be done if the deceased has indicated a wish during his or her lifetime that tissue be donated for transplantation use after death. If the deceased has not indicated his or her wish to be a tissue donor, family members could be asked to consent to a donation. The article looks at the legal requirements in South Africa for a valid skin donation as well as the requirements should skin be imported owing to a lack of enough tissue donors in the country. This position is contrasted to the position in the United Kingdom with a view to establishing whether South Africa can learn from another jurisdiction concerning the procurement of skin for transplantation. The possible reasons that people do not donate skin are also touched upon.

Extremely thin sclera often necessitates abortion of scleral buckle procedures. In patients in whom a scleral buckle is desired, previous techniques have included the use of cyanoacrylate glue and continuing with surgery or placing donor tissue over the areas of thin sclera, but this can delay surgery. This was a retrospective review of three patients with thin sclera encountered during scleral buckling procedures. All patients had Tutoplast Pericardial Graft placed over the areas of thin sclera which allowed the scleral buckle to be sutured onto the Tutoplast rather than the thin sclera. Tutoplast Pericardial Graft is a useful adjunct in scleral buckle procedures with extremely thin sclera, and a scleral buckle can be safely placed over it and lead to successful retinal reattachment.

Purpose: This study investigated the clinical outcomes achieved with a newly developed donor inserter (NS Endo-Inserter [NSI], HOYA Co., Ltd., Tokyo, Japan) for Descemet’s stripping automated endothelial keratoplasty (DSAEK) in Japanese eyes with bullous keratopathy secondary to argon laser iridotomy (BK-ALI). The NSI device utilizes pressure flow to push the DSAEK donor tissue into the anterior chamber. Methods: Six eyes of 6 patients (1 male, 5 females; mean age, 78.5 years) with BK-ALI were enrolled. Donor tissue was pushed into the anterior chamber using the NSI. Intraoperative complications, graft dislocation, and iatrogenic primary graft failure were recorded for all eyes. Six-month postoperative central donor endothelial cell densities (ECD) were measured prospectively and compared with preoperative values, along with 6-month best corrected visual acuity (BCVA). Results: In all cases, donor loading onto the NSI spatula and donor insertion into the anterior chamber using the NSI was smooth and successful; no intraoperative complications were noted. There were no cases of graft dislocation or IPGF. Postoperative ECD was 2,187.2 cells/mm2 (mean loss, 14.8%) and mean BCVA increased from 0.27 decimal to 0.8 at 6 months. Conclusion: In this small preliminary case series, clinical outcomes for patients with BK-ALI undergoing DSAEK using the NSI were comparable or better than those achieved with conventional DSAEK insertion techniques.

We report a new technique to replace a manufactured poly(methyl methacrylate) (PMMA) ring with a biologic stromal ring fashioned from human corneal donor tissue in eyes with stromal melting above the PMMA ring. The biologic stromal ring is prepared using manual or femtosecond laser trephination of a donor cornea to obtain a 360-degree ring that is denuded and adjusted to match the PMMA ring being replaced. The biologic ring is attached to the PMMA ring. The PMMA ring is pushed and retrieved from the other side, which installs the biologic ring in place. Six biologic stromal rings were implanted successfully in 5 eyes of 5 patients with previous stromal melting; no complications were reported up to 6 months postoperatively. The biologic stromal ring stopped and healed the melting, prevented further ring complications, and preserved the therapeutic refractive effect of the previously implanted PMMA ring.

The Peters’s Anomaly (PA) is an infrequent congenital anomaly of a cornea and anterior segment of eye. The rarity of this pathology and difficulty bound to inspection of newborns generate a situation when more or less certain clinical approaches to maintaining this anomaly remain obscure for most of children’s ophthalmologists. Purpose. To study clinical implications and to estimate results of surgical treatment in children with PA. Material and methods. Under observation from 1996 for 2016 on examination and treatment there were 51 children with the PA different forms, aged from 3 months up to 10 years: 1 group – mesodermal – 20 people (37%), 2 – group the ectodermal 31 child (63%). Surgical treatment – penetrating keratoplasty (PKP) was carried out at 43 patients (69 eyes) aged from 8 up to 36 months. At other children (8 people) surgery was contraindicative because of serious somatic and eye pathology. Clinical-functional and ophthalmologic examination at all was conducted in the conditions of medication sleep. PKP carried out by a traditional technique, as donor material used a fresh cadaver cornea with prescription of a fence from death moment before operation no more than 48 hours. The biological result of surgery was estimated by a moment method (or Kaplana-Maier’s method) by means of which calculated so-called survival of a graft. Functional result – at children to 3-x years estimated approximately: on tracking of the child toys from a certain distance and method of a preferable look, at children of advanced age according to Sivtsev-Golovin’s table. Postoperative observation proceeded from 3 months to 15 years. The corneal disks removed during surgery were exposed to a histological research. Results. Within the first year after PKP a transparence of the replaced cornea remained in 1 group on 29 eyes (90%), in 2 group – at 21 patients of 26 eyes (67%). In 2 years after surgery the transparent donor cornea at children in 1 group remained at 17 patients (20 eyes, 62%); in – the second at 15 patients of 18 eyes (54%). In 5 years after surgery – at patients of 1 group a transparence of the replaced donor tissue was kept by 17 eyes (53%), in the second only 12 of 31 executed surgery (39%). In 10 years transparent were 53% and 31% of corneas, respectively. In 15 years after surgery a transparence was kept in 1 group of 15 eyes (46%), in 2 – on 9 (22%). Visual acuity (0,3 and above) was observed at 8 of 13 children (61%) after surgery about one year at children of advanced age only in 27% of cases, even at tr ansparent engraftment of a graft. Conclusion. The keratoplasty at PA at children of early age is the only chance to save the child from a blindness and disability on vision.

Our objectives were to identify barriers to the organ donation registration process in Ontario; and to determine the acceptability of using the emergency department (ED) waiting room to provide knowledge and offer opportunities for organ and tissue donor registration.We conducted a paper based in-person survey over nine days in March and April 2017. The survey instrument was created in English using existing literature and expert opinion, pilot tested and then translated into French. Data was collected from patients and visitors in an urban academic Canadian tertiary care ED waiting room. All adults in the waiting room were approached to participate during study periods. We excluded patients who were too ill and required immediate treatment.The number of attempted surveys was 324; 67 individuals (20.7%) declined participation. A total of 257 surveys were distributed and five were returned blank. This gave us a response rate of 77.8% with 252 completed surveys. The median age group was 51-60 years old with 55.9% female. Forty-six percent reported their religion as Christian and 34.1% did not declare a religious affiliation. 44.1% were already registered donors. Most participants agreed or were neutral that the ED waiting room was an acceptable place to provide information on donation, and for registration as an organ and tissue donor (83.3% and 82.1%, respectively).Individuals waiting in the ED are generally supportive of using the waiting room for distributing information regarding organ and tissue donation, and to allow donor registration.L’étude avait pour objectifs : 1) de relever les obstacles au processus d'inscription du don d'organes en Ontario; 2) de déterminer l'acceptabilité sociale de l'utilisation de la salle d'attente du service des urgences (SU) comme lieu de diffusion de l'information sur les dons de matériel biologique, et d'inscription de donneurs d'organes et de tissus.Une enquête a été menée en personne, au moyen d'un questionnaire sur papier, durant 9 jours, en mars et en avril 2017. L'instrument d'enquête a d'abord été élaboré en anglais à l'aide de la documentation existante et de l'avis d'experts, puis soumis à un essai pilote avant d’être traduit en français. La collecte de données s'est faite parmi les patients et les personnes qui les accompagnaient dans une salle d'attente d'un SU d'enseignement, de soins tertiaires, situé en milieu urbain, au Canada. Tous les adultes présents dans la salle d'attente ont été invités à participer à l’étude durant la période en question. Ont été exclus les patients qui étaient trop malades ou dont l’état nécessitait des soins immédiats.Il y a eu 324 demandes d'enquête et 67 personnes (20,7%) ont refusé de participer. Sur un total de 257 questionnaires remis, 5 ont été rendus vierges, ce qui a porté à 77,8% (252 questionnaires remplis) le taux de réponse. L’âge médian était de 51–60 ans, et 55,9% des répondants étaient des femmes. Quarante-six pour cent des participants se sont déclarés chrétiens et 34,1% n'ont rien indiqué quant à leur appartenance religieuse; par ailleurs, 44,1% étaient déjà des donneurs inscrits. La plupart des répondants se sont montrés favorables ou neutres à l’égard de l'utilisation de la salle d'attente du SU comme lieu de diffusion de l'information sur les dons de matériel biologique, ou d'inscription de donneurs d'organes et de tissus (83,3% et 82,1%, respectivement).Dans l'ensemble, les personnes interrogées au SU se sont montrées favorables à l'utilisation de la salle d'attente comme lieu de diffusion de l'information sur les dons d'organes et de tissus, et d'inscription de donneurs.

Background Split-thickness skin grafts (STSGs) are commonly used in the reconstruction of skin defects induced by trauma or burns. Although STSGs are used to successfully treat various wound types, donor site wounds can be challenging, and complications often develop. Therefore, optimal donor site dressings are required. In this study, we introduce an evidence base for patterns in how the discharge amount decreases over time, with the goal of providing insights into the selection of dressing materials. Methods Twenty patients with burns who received STSGs harvested from the thigh between January 2016 to April 2017 were prospectively reviewed. A donor site dressing with foam was changed daily. The weight of the foam dressing was measured before and after placement on the donor site. The wound area was calculated using Visi-Trak. The mean weight of the discharge amount per unit area (g/10 cm2) was calculated. Results The mean weight of the discharge amount per unit area (g/10 cm2) decreased from 3.84 to 2.02 (P

Aim: To study the five-year endothelial cell loss in patients having undergone penetrating keratoplasty (PKP) and who received corneal donor tissue from international eye banks. Methods: This retrospective clinical study reviewed outcomes in 41 patients who underwent PKP at a tertiary eye center from February 2008 to July 2011. Standard PKP surgical technique was used for all patients, and graft tissue was supplied in all cases by eye banks in the United States of America. At five years after surgery, measurements were taken of endothelial cell density (ECD), coefficient of variation, hexagonality, donor’s age, recipient’s age, Death-to-preservation (DP), and preservation time (PT). Results: The recipients and donors median age was 30.0 years (24.0–35.5 years) and 59.0 years (53.0–61.0 years) respectively; the median DP and PT were 8.0hours.(6.0–10.0hours) and 10.0 days (9.0–11.5 days) respectively. At baseline, the ECD was 2398(2325–2525). At five years after surgery, all of the grafts were found to have survived; the median ECD was 1035 cell/mm2 (693–1346 cell/mm2); the mean coefficient of variation was 35.2 ± 9.8%; and the mean hexagonality was 63.7 ± 24.3%. The overall ECD loss was 56% (95% CI: 50–62%); the ECD loss was 51.3% and 61.2% in corneas from donors younger and older than 60 years respectively (p = 0.056); likewise, the ECD loss was 52.6% and 61.0% in corneas with PT shorter and longer than 10 days respectively (p = 0.289). Although the difference in both cases was not statistically significant, it was clinically important (about 10%). Conclusion: The ECD after five years in patients undergoing internationally-transported corneal tissue grafts incurred 56% loss; the donor’s age and the PT were positively associated with ECD loss. Keywords: Penetrating keratoplasty, Corneal endothelial cell loss, Corneal endothelial polymegathism, Corneal endothelial pleomorphism

Purpose: To study the trends in collection, storage and utilization of donor corneas in eye banks in India. Methods: The data was collected from 12 eye banks in India that collected more than 1000 corneas per year. The retrospective analysis of the parameters like characteristics of the donor and the host, storage media used, number of eyes collected, number of eyes utilized, causes of non-utilization of the tissue and the procedures performed was done. Results: A total of 20,564 eyes were collected by the 12 eye banks during the year 2013–2014. Voluntary eye donation (VED), and hospital cornea retrieval program (HCRP) contributed to 59.6% and 40.4% of tissue procurement respectively. Whole globe enucleation (52.3%) was more commonly performed as compared to in-situ excision of the donor corneas. The most commonly used storage media at all eye banks was McCarey-Kaufman (MK) media (83.3%). The utilization rate of the donor eyes was 50.5%. The most frequent indication for corneal transplantation was infection (active infection - 33.13%, healed infection - 10.78%) followed by Pseudophakic bullous keratopathy (PBK) (13.57%). Full thickness keratoplasty (optical penetrating keratoplasty - 47.23%, therapeutic penetrating keratoplasty - 31.74%) was performed most often followed by endothelial keratoplasty (12.41%) in the developing country. Conclusion: VED still contributes to majority of the donor tissue retrieval in India. The majority of the eye banks still utilize whole globe enucleation technique and store tissues in MK media. Trends from previous years showed a change towards HCRP, in-situ excision technique and preservation in the long-term storage media.

Purpose: To describe a simple technique of sinsky hook assisted roll preparation (SHARP) for Descemet membrane endothelial keratoplasty (DMEK) donor preparation. Methods: This experimental study was conducted at National Eye Bank, India with 40 optical grade human donor corneoscleral tissues found not suitable for surgery. 25 tissues were initially used to standardize the technique and remaining 15 for establishing the final technique. Donor corneal tissues were initially placed on a sterile Teflon block partially filled with tissue culture media. Initially, a partial thickness trephination was done followed by sinsky assisted 360° separation of the Descemet membrane (DM) from the underlying stroma (2 mm from the edge). The separation was further extended by 3–4 mm from the edge for 4–5 clock hours followed by bimanual peeling of the DM. This was followed by central 8 mm trephination. The primary outcome measures were a complete success (8 mm roll without peripheral edge tears) and partial success (8 mm roll with peripheral edge tears). Results: DMEK roll was successfully peeled in 86.6% tissues (n = 13/15). Complete success was obtained in 66.6% tissues while partial success was obtained in 20% tissues. The median age of donor tissue was 45 years. The donor age of tissues, from which DMEK roll could not be obtained (2/12) was 15 days and 18 years. Conclusion: SHARP is a simple technique of DMEK that does not require any sophisticated instruments. Keywords: DMEK, Endothelial keratoplasty, Keratoplasty

Purpose of Review: The ocular surface is a potential site of ocular involvement by SARS-CoV-2 infection. We performed a review of the literature to understand the pathogenesis of SARS-CoV-2 disease manifestations on the ocular surface as well as to elucidate emerging treatment patterns and practice changes during the COVID-19 pandemic. Recent Findings: The ocular manifestations of SARS-CoV-2 are likely limited to a mild and transient conjunctivitis. Other manifestations have not been validated in larger cohorts. Ocular surface tissue should be considered potentially infectious due to the presence of host receptors on surface tissues. The availability of donor tissue in lower-middle income countries has been greatly impacted by the pandemic and would benefit from further investigation into transmissibility through donor tissue. Summary: Transmission of SARS-CoV-2 through the ocular surface has yet to be confirmed. The most common ocular manifestation is a mild conjunctivitis. Ocular surface surgeons face specific challenges in the use of donor tissues and aerosolizing procedures and have adapted practice patterns accordingly.

Introduction. The purpose of this case report was to show the clinical long-term stability of a successful two-step root coverage procedure. A combination of two single techniques was used to treat an isolated deep-wide defect. Case Presentation. A 28-year-old female patient was referred in order to treat a single recession defect at #22. Due to her fear of dental procedures and a poor economic situation, the team developed an alternative solution. They used a modified apically repositioned flap (MARF) to increase the donor area and then a laterally positioned flap (LPF) to treat the root defect. Clinical evaluation at the three-year follow-up revealed complete resolution of the defect, a gain in clinical attachment, excellent esthetic results, and minor morbidity to the patient. Conclusion. The combination of the MARF and the LPF procedures was able to successfully treat a single deep recession defect with some advantages over traditional techniques such as simplicity, ideal color match of tissues, and the absence of palatal donor tissue.

Mesenchymal stem cells (MSCs) are of great interest for their use in cell-based therapies due to their multipotent differentiation and immunomodulatory capacities. In consequence of limited numbers following their isolation from the donor tissue, MSCs require extensive expansion performed in traditional 2D cell culture setups to reach adequate amounts for therapeutic use. However, prolonged culture of MSCs in vitro has been shown to decrease their differentiation potential and alter their immunomodulatory properties. For that reason, preservation of these physiological characteristics of MSCs throughout their in vitro culture is essential for improving the efficiency of therapeutic and in vitro modeling applications. With this objective in mind, many studies already investigated certain parameters for enhancing current standard MSC culture protocols with regard to the effects of specific culture media components or culture conditions. Although there is a lot of diversity in the final therapeutic uses of the cells, the primary stage of standard isolation and expansion is imperative. Therefore, we want to review on approaches for optimizing standard MSC culture protocols during this essential primary step of in vitro expansion. The reviewed studies investigate and suggest improvements focused on culture media components (amino acids, ascorbic acid, glucose level, growth factors, lipids, platelet lysate, trace elements, serum, and xenogeneic components) as well as culture conditions and processes (hypoxia, cell seeding, and dissociation during passaging), in order to preserve the MSC phenotype and functionality during the primary phase of in vitro culture.

Purpose In patients with corneal melt, pretreatment crosslinking (CXL) of donor tissue prior to placement of Boston keratoprosthesis (K-Pro I) decreases graft failure. We report a case of corneal sparing in a phthisical eye following penetrating keratoplasty (PKP) with pretreatment CXL of the donor cornea. Observations A 69-year-old female with a history of familial aniridia and bilateral K-Pro I placement. Her clinical course was complicated by recurrent corneal melt and hypotony in the left eye, resulting in extraction of the K-Pro I and successive PKP with pretreatment CXL of the donor cornea. She subsequently developed phthisis of the globe with notable retention of corneal structure. At 8 years, she maintains corneal contour without recurrence of keratolysis or extension of phthisis. Conclusions and importance This is the first reported case of corneal sparing in a phthisical eye with a history of PKP, suggesting a protective role of pretreatment CXL of donor tissue against keratolysis and phthisis.

PURPOSE To evaluate the effects of femtosecond laser-assisted keratoplasty using a liquid patient interface (L-PI) as opposed to an applanated interface (A-PI) on graft quality and functionality markers. METHODS Pressure measurements during femtosecond laser-assisted trephination were performed using two groups of 10 porcine eyes. Trephination was performed either in an L-PI or in an A-PI setting. Pressure sensor needles placed intravitreally continuously recorded intraocular pressure during trephination. Twenty paired human donor eyes were used to test the morphological quality of donor tissue after trephination in L-PI and A-PI settings. Optical coherence tomography (OCT) scans were performed before and after trephination. Images were processed using ImageJ and pixel2 . RESULTS During trephination, pressure measurements with an L-PI were significantly lower than with an A-PI (p = 0.0121). Mean pressure during trephination was 78.1 mmHg ± 37.6 mmHg with L-PI and 188.6 mmHg ± 17.7 mmHg with A-PI. Trephination in A-PI produced a significantly larger increase (p

The objective of this article is to share how our institution implemented the use of organ donors for surgical education following organ recovery. Despite technological advances, realistic surgical simulation models are lacking, leaving little opportunity to practice a procedure prior to performance on a living patient. Utilization of organ donors following organ donation offers an opportunity for life-like surgical simulation. We developed a pathway to use organ donor tissue in the post-recovery period for robotic simulation. We obtained support from our local Institutional Review Board, Ethics Committee, and organ procurement organization to create a "knowledge donor" program. Our knowledge donation program provided learners hands-on experience with a novel procedure and also provided organ donors another opportunity to express their altruism. We found that the process was well accepted by donor families and learners. We implemented a knowledge donation program at our hospital that provides valuable surgical experience. We discuss future directions for knowledge donation at our institution.

We review studies on tissue transplantation experiments for various species: one piece of the donor tissue is excised and transplanted into a slit in the host tissue, then observe the behavior of this grafted tissue. Although we have known the results of some transplantation experiments, there are many more possible experiments with unknown results. We develop a penalty function-based method that uses the known experimental results to infer the unknown experimental results. Similar experiments without similar results get penalized and correspond to smaller probability. This method can provide the most probable results of a group of experiments or the probability of a specific result for each experiment. This method is also generalized to other situations. Besides, we solve a problem: how to design experiments so that such a method can be applied most efficiently.

Background: Fresh osteochondral allograft transplant (OCA) has good outcomes in the knee. However, donor tissue for patellar OCA is limited. Outcomes after nonorthotopic OCA of the patella using more readily available femoral condylar allograft (FCA) tissue have not been previously reported. Purpose: To assess short-term magnetic resonance imaging (MRI) and minimum 2-year clinical outcomes of nonorthotopic patellar OCA using an FCA donor. Study Design: Case series; Level of evidence, 4. Methods: A prospective institutional cartilage registry was reviewed to identify patients treated with patellar OCA using an FCA donor between August 2009 and June 2016. OCA plugs were obtained from the FCA at its trochlear-condylar junction and implanted into the recipient patellar lesion. Early postoperative MRI scans were graded by a blinded musculoskeletal radiologist using the Osteochondral Allograft MRI Scoring System (OCAMRISS). International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC), Knee Outcomes Survey–Activities of Daily Living (KOS-ADL), and pain visual analog scale (VAS) scores were collected preoperatively and at minimum 2 years postoperatively, and outcomes were compared using the paired t test. Results: A total of 25 patients were included for clinical outcome analysis and 20 patients for MRI analysis. MRI scans obtained at a mean of 11.4 months (range, 6-22 months) postoperatively showed a mean total OCAMRISS score of 9.0 (range, 7-11); mean bone, cartilage, and ancillary subscores were 2.6, 3.7, and 2.6, respectively. At the latest follow-up (mean, 46.5 months; range, 24-85 months), postoperative improvements were noted in IKDC (from 45.0 to 66.2; P = .0002), KOS-ADL (from 64.3 to 80.4; P = .0012), and VAS (from 5.1 to 3.4; P = .001) scores, with IKDC and KOS-ADL scores above the corresponding previously reported minimal clinically important difference. Conclusion: In this study, patellar OCA using nonorthotopic FCA led to significant short-term improvements in pain and patient-reported outcomes. The majority of nonorthotopic patellar grafts demonstrated full osseous incorporation and good restoration of the articular surface on MRI at short-term follow-up.

One of the leading trends in the modern tissue engineering is the development of new effective methods of decellularization aimed at the removal of cellular components from a donor tissue, reducing its immunogenicity and the risk of rejection. Supercritical CO2 (scCO2)-assisted processing has been proposed to improve the outcome of decellularization, reduce contamination and time costs. The resulting products can serve as personalized tools for tissue-engineering therapy of various somatic pathologies. However, the decellularization of heterogeneous 3D structures, such as the aortic root, requires optimization of the parameters, including preconditioning medium composition, the type of co-solvent, values of pressure and temperature inside the scCO2 reactor, etc. In our work, using an ovine aortic root model, we performed a comparative analysis of the effectiveness of decellularization approaches based on various combinations of these parameters. The protocols were based on the combinations of treatments in alkaline, ethanol or detergent solutions with scCO2-assisted processing at different modes. Histological analysis demonstrated favorable effects of the preconditioning in a detergent solution. Following processing in scCO2 medium provided a high decellularization degree, reduced cytotoxicity, and increased ultimate tensile strength and Young&rsquo, s modulus of the aortic valve leaflets, while the integrity of the extracellular matrix was preserved.

Purpose This study compares the quality of donor corneal tissue stored in Optisol-GS and Cornea Cold. Methods Seventeen pairs of donor corneas were obtained from an eye bank. One of each pair was stored in Cornea Cold or Optisol-GS. Endothelial cell loss (ECL), central corneal thickness (CCT), and endothelial cell density (ECD) were measured at 7 and 21 days of storage. Qualitative metrics were evaluated by using a slit lamp. Results At days 7 and 21, there were no observed differences in qualitative corneal health of the samples. There were no statistical differences in the mean ECL at 7 and 21 days between the 2 groups (P = 0.07 and P = 0.50, respectively). At 7 days, the mean CCT was 644 ± 52 μm in the Cornea Cold group and 591 ± 64 μm in the Optisol-GS group (P = 0.001). At 21 days, CCT was 714 ± 55 μm in the Cornea Cold group and 708 ± 58 μm in the Optisol-GS group (P = 0.70). The mean ECD was not statistically different between the groups (P = 0.56 at 7 days and P = 0.14 at 21 days). Conclusions Storage of corneal donor tissue in the Optisol-GS and Cornea Cold storage media resulted in statistically comparable ECL and ECD for up to 21 days. CCT was higher in Cornea Cold at 7 days, but this discrepancy disappeared at 21 days.

Background Deceased organ donors represent an untapped source of therapeutic bone marrow (BM) that can be recovered in 3–5 times the volume of that obtained from living donors, tested for quality, cryopreserved, and banked indefinitely for future on-demand use. A challenge for a future BM banking system will be to manage the prolonged ischemia times that are inevitable when bones procured at geographically-dispersed locations are shipped to distant facilities for processing. Our objectives were to: (a) quantify, under realistic field conditions, the relationship between ischemia time and the quality of hematopoietic stem and progenitor cells (HSPCs) derived from deceased-donor BM; (b) identify ischemia-time boundaries beyond which HSPC quality is adversely affected; (c) investigate whole-body cooling as a strategy for preserving cell quality; and (d) investigate processing experience as a variable affecting quality. Methods Seventy-five bones from 62 donors were analyzed for CD34+ viability following their exposure to various periods of warm-ischemia time (WIT), cold-ischemia time (CIT), and body-cooling time (BCT). Regression models were developed to quantify the independent associations of WIT, CIT, and BCT, with the viability and function of recovered HSPCs. Results Results demonstrate that under “real-world” scenarios: (a) combinations of warm- and cold-ischemia times favorable to the recovery of high-quality HSPCs are achievable (e.g., CD34+ cell viabilities in the range of 80–90% were commonly observed); (b) body cooling prior to bone recovery is detrimental to cell viability (e.g., CD34+ viability with, vs. > 89% without body cooling); (c) vertebral bodies (VBs) are a superior source of HSPCs compared to ilia (IL) (e.g., %CD34+ viability > 80% when VBs were the source, vs. Conclusions Our models can be used by an emerging BM banking system to formulate ischemia-time tolerance limits and data-driven HSPC quality-acceptance standards.

One of the leading trends in the modern tissue engineering is the development of new effective methods of decellularization aimed at the removal of cellular components from donor tissue reducing its immunogenicity and the risk of rejection. Supercritical CO2 (scCO2) extraction can significantly improve the outcome of decellularization, reduce contamination and time costs. The resulting products can serve as personalized tools for tissue-engineering therapy of various somatic pathologies. However, decellularization of complex 3D structures, such as the aortic root, requires optimization of the parameters, including preconditioning medium composition, type of co-solvent, values of pressure and temperature insight the scCO2 reactor, etc. In our work, using an ovine aortic root model, we performed a comparative analysis of the efficiency of decellularization using approaches based on various combinations of these parameters. The protocols were based on combinations of treatment in alkaline, ethanol or detergent solutions with scCO2 extraction at different modes. Based on a histological analysis, we have selected an optimal protocol for the decellularization of ovine aortic root employing preconditioning in a detergent solution. The positive effects of scCO2 on the decellularization extent, cytotoxicity and histoarchitecture of the tissue were demonstrated.

Induced pluripotent stem cells (iPSC)‐based therapies have been hailed as the future of regenerative medicine because of their potential to provide treatment options for most degenerative diseases. A key promise of iPSC‐based therapies is the possibility of an autologous transplant that may engraft better in the longer‐term due to its compatibility with the patient's immune system. Despite over a decade of research, clinical translation of autologous iPSC‐based therapies has been slow—partly due to a lacking pre‐defined regulatory path. Here, we outline regulatory considerations for developing an autologous iPSC‐based product and challenges associated with the clinical manufacturing of autologous iPSCs and their derivatives. These challenges include donor tissue source, reprogramming methods, heterogeneity of differentiated cells, controls for the manufacturing process, and preclinical considerations. A robust manufacturing process with appropriate quality controls and well‐informed, prospectively designed preclinical studies provide a path toward successful approval of autologous iPSC‐based therapies., Regulatory considerations for developing a phase I investigational new drug application for an autologous induced pluripotent stem cells‐based therapy.

Recent research in the field of positive psychology has concentrated efforts towards understanding positive prosocial emotional experiences in relation to prosocial behavior. Elevation is one of these emotions that has been described as a powerful and positive mood state that can be experienced by witnessing social moral acts (Haidt, 2000) and has recently been linked to increases in prosocial behavior (Freeman, Aquino, M Landis, Sherman, Piedmont, Kirkhart, Rapp, & Bike, 2009; Schnall, Roper, &Fessler, 2010). This study investigated the emotion elevation in relation to decision-making for the prosocial health behavior of becoming an organ and tissue donor. The study was experimental and compared decision making for becoming an organ and tissue donor across experimental and control groups. Participants were randomized to one of the three conditions (elevation, mirth, and neutral state) to see if elevation versus control conditions influenced attitudes and behaviors in regards to organ and tissue donation decision-making, and stress management before and after watching a brief video clip. The methodology was also novel in that an online video induction of elevation has not been previously investigated. It was hypothesized that elevation would lead to increased readiness to become an organ and tissue donor, as well as endorsement of greater Pros, SelfEfficacy, engagement, and stress management. Results indicated that participants in the elevation condition reported significantly higher ratings of state elevation compared to positive and neutral control groups supporting that elevation can be induced with an online video protocol. Post-test results indicated that state elevation was not predictive of group differences on decisional balance, self-efficacy, stage, engagement, actual registration for organ and tissue donation, and stress management. As predicted, women reported significantly greater trait elevation than men and trait elevation was significantly related to stage for organ and tissue donation. Questions remain as to the utility of moral elevation state to impact prosocial behaviors. Limitations are discussed and suggestions for future research include utilizing online video induction of moral elevation to better understand the behavioral antecedents of this emotion in naturalistic settings.

Corneal injury is a known risk for deployed troops worldwide. To the authors’ knowledge, there has been no reported use of gamma-irradiated corneas in the setting of severe corneal trauma. Our report highlights the case of a 36-year-old active duty solider who sustained bilateral penetrating ocular trauma from a nearby ordnance explosion. We propose that ocular surgeons should consider utilizing gamma-irradiated corneas in (1) a situation where the corneal tissue is so damaged that it would be challenging to accomplish an adequate repair while providing the opportunity for future visual rehabilitation and (2) remote and/or deployed environments where storage of fresh donor tissue is limited. The long shelf life of gamma-irradiated corneas reduces the need for specialized storage equipment and the need for continuous resupply, both potentially leading to significant cost savings for the Military Health System.

The approach to nasal reconstruction is based on the nature of the defect and the donor tissue. The Rintala flap, first described by Rintala and Asko-Slejavaara, is a surgical technique used to close midline nasal defects. It is a simple, one-stage procedure and is most effective for defects ranging from 1.5 to 2.5 centimeters. In addition, the Rintala flap is an excellent tissue match and maintains the natural contour of the nose. Other flaps employed in nasal defect closure include the paramedian forehead flap and the Rieger flap. The authors discuss the Rintala flap technique and utility with comparison to alternative flaps used for nasal reconstruction.

Purpose To assess the effect of donor tissue diameter in Descemet Membrane Endothelial Keratoplasty (DMEK) on postoperative endothelial cell density (ECD) mainly in Fuchs Endothelial Corneal Dystrophy (FECD) patients. Methods Retrospective review of 693 consecutive DMEK surgeries from the prospective Cologne DMEK database performed between 07/2011 and 07/2016 at the Department of Ophthalmology, University of Cologne. Eight- versus ten-millimetre large donor DMEK grafts of two different surgeons using identical surgical techniques were compared. Results A total of 693 consecutive DMEK surgeries were included. Two groups (8 versus 10 mm DMEK graft diameter) were compared: 23% of eyes received 8-mm grafts (group 1, n = 160) and 77% 10-mm grafts (group 2, n = 533). Mean preoperative ECD (±SD) of donor tissue was 2736 ± 224 cells/mm2 in group 1 and 2714 ± 232 in group 2. Group 1 showed a mean ECD of 1740 ± 439 cells/mm2 (mean ± SD; n = 67) 12 months after DMEK compared to 1664 ± 404 cells/mm2 (mean ± SD; n = 344) in group 2. The difference between the 6- and 12-month ECD of both groups was not significant (p = 0.675; p = 0.161). Total decrease in ECD 6- and 12-months postoperatively was 38 ± 14 (n = 128) and 36 ± 16% in group 1 (n = 66) versus 37 ± 15% (n = 398) and 38 ± 15% in group 2 (n = 342; p = 0.414; p = 0.198, respectively). Conclusion Our data suggest that postoperative central endothelial cell density is not significantly associated with DMEK graft diameters in the range of 8-10 mm in cases with healthy peripheral host endothelium (such as FECD).

Purpose: To report a modified surgical technique called the “donor tissue holding technique for Descemet’s membrane endothelial keratoplasty (DMEK)” using a newly developed 25-gauge graft manipulator. Methods: Six consecutive patients exhibiting endothelial dysfunction were enrolled and treated by DMEK. In brief, after insertion of a DMEK donor into the anterior chamber, the edge of the roll was grasped using a graft manipulator and this grasp was maintained throughout the centering and opening of the roll (holding technique). The following parameters were evaluated in comparison to the previous 10 consecutive DMEK cases in which the no touch technique was used: time of graft unfolding, incidence of intra-/postoperative complications, and best spectacle-corrected visual acuity (BCVA) and endothelial cell density (ECD) 6 months after the procedure. Results: In both technique groups, neither intra- nor postoperative complications were noted in any case. No differences were observed between the two groups in postoperative BCVA (p = 0.88). Also, no differences were observed between the two groups in postoperative ECD (holding technique group: 2,108.3 cells/mm2, no touch technique group: 1,491.7 cells/mm2) (p = 0.08) Most notably, the time of graft unfolding prior to filling with air was significantly reduced in the holding technique group (305.5 s) compared to that of the no touch technique group (1,310.0 s; p = 0.01). Conclusions: This donor tissue holding technique enabled rapid and safe DMEK in a reproducible manner, even in Asian eyes with shallow anterior chambers with high vitreous pressure.

Free gingival graft is one of the technique used for root coverage so as to increase the inadequate keratinized tissue. The donor tissue is most frequently taken from the palate and generally the donor site is not covered or protected. Platelet rich fibrin is one of the good option for the wound coverage of donor site after free gingival graft so as to reduce the pain perception to patient and faster wound healing. The case report includes two cases with gingival recession, treated on the same day with free gingival graft with the use of platelet rich fibrin in the donor site in case 1 and without platelet rich fibrin in case 2 respectively which were compared for pain perception and wound healing postoperatively at 24 hours, 3 days, 5 days, 7 days and 14 days. There was less pain perception and discomfort in the donor site with the use of platelet rich fibrin and enhanced healing compared to donor site without platelet rich fibrin. Keywords: Donor site; free gingival graft; platelet rich fibrin.

Ahmedbeyli, Cavid/0000-0002-4699-0041 WOS:000456712300010 PubMed: 29725851 ObjectivesThe aim of this study was to evaluate acellular dermal matrix graft (ADM) combination with laterally positioned flap (LPF) and to compare the results with LPF alone in terms of root coverage, esthetics, and patient perspectives in gingival recessions.Materials and methodsTwenty-two patients with localized Miller Class I/II recessions 3mm with gingival thickness (GT)

Xenogeneic bone substitute materials are widely used in oral implantology. Prior to their clinical use, purification of the former bone tissue has to be conducted to ensure the removal of immunogenic components and pathogens. Different physicochemical methods are applied for purification of the donor tissue, and temperature treatment is one of these methods. Differences in these methods and especially the application of different temperatures for purification may lead to different material characteristics, which may influence the tissue reactions to these materials and the related (bone) healing process. However, little is known about the different material characteristics and their influences on the healing process. Thus, the aim of this mini-review is to summarize the preparation processes and the related material characteristics, safety aspects, tissue reactions, resorbability and preclinical and clinical data of two widely used xenogeneic bone substitutes that mainly differ in the temperature treatment: sintered (cerabone®) and non-sintered (Bio-Oss®) bovine-bone materials. Based on the summarized data from the literature, a connection between the material-induced tissue reactions and the consequences for the healing processes are presented with the aim of translation into their clinical application.

Most Canadians believe organ donation is the right thing to do, but motivating them to register as donors may require a particular turn of phrase, according to researchers from the University of British Columbia (UBC) Many organ and tissue donor agencies advertise how few people are registered as donors, hoping to encourage registration by demonstrating need, said Rishad Habib, a PhD candidate in marketing and consumer studies at UBC However, creating the perception that "nobody is doing something" can easily backfire "You automatically reduce how important it is," Habib said Campaigns that emphasize broad social support for organ donation can also backfire by leading people to believe that others are already helping, diffusing any personal responsibility to register, Habib said

OBJECTIVE The objective of this study is to reduce donor tissue wastage. AIM The aim of this study is to determine, in the case of the Abbott Architect rHTLV I/II assay, whether a signal/cut-off (S/CO) ratio higher than the manufacturer's recommendation of 1·0 could be applied to diagnose significant HTLV-1 seroreactivity. BACKGROUND The detection of human T cell leukaemia virus type 1 (HTLV-1) infection is primarily based on serology often utilising random access platforms. Although current assays have high sensitivity and specificity, in low-prevalence regions, significant numbers of false-positive reactions occur. A comprehensive follow-up is difficult within the time frame of organ donation. This can lead to donor tissue wastage. METHODS A retrospective analysis of 12 250 samples previously tested on the Abbott Architect rHTLV I/II platform and further tested by confirmatory serology/molecular detection to determine the sensitivity and positive predictive value in the S/CO ratio range was conducted. RESULTS Where the sample S/CO ratio was >20 (n = 498), HTLV infection was confirmed in all but eight subjects. All of these eight had indeterminate confirmatory results, and none were found to be uninfected. Conversely, in the samples within the S/CO ratio range 1-4 (n = 271), no subject was subsequently found to be HTLV-infected although HTLV infection could not be excluded in all cases, primarily due to lack of follow-up samples (n = 60/271). CONCLUSIONS Samples with an S/CO ratio of

Purpose: To compare the safety, efficacy, and clinical outcomes of simple limbal epithelial transplantation (SLET) with conjunctival-limbal autologous transplantation (CLAU) in severe unilateral ocular chemical burns. Materials and Methods: Twenty patients of unilateral chronic ocular burns with more than 270° limbal stem cell deficiency and a healthy fellow eye were divided into two groups – ten patients of Group A underwent SLET while ten patients of Group B were operated for CLAU. Patients were followed up for 6 months and assessed for a stable epithelialized ocular surface, extent of reduction in vascularization and forniceal reconstruction, improvement in corneal clarity and visual acuity. Results: A stable epithelialized corneal surface was obtained in all patients, with a significant reduction in the mean clock hours of vascularization in both the groups (P < 0.001). The mean symblepharon score showed a statistically significant reduction from 1.80 ± 1.14 to 0.30 ± 0.63 in Group A and 1.70 ± 1.06 to 0.15 ± 0.24 in Group B at 6 months. Corneal clarity, as well as best-corrected visual acuity, showed a statistically significant improvement in both the groups. Conclusion: Both the procedures, SLET and CLAU, were equally effective in achieving a stable ocular surface, forniceal reconstruction, and regression of corneal vascularization. The requirement of minimal donor tissue in SLET makes it a preferred option over CLAU in cases of uniocular chronic ocular burns.

Objective To evaluate early in vivo corneal wound healing findings after Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK) by using in vivo confocal microscopy. Method A total of 15 eyes of 15 patients were included. In vivo confocal microscopy (Confoscan 4, Fortune Technologies, Italy) was performed from 4 to 7 weeks after DSAEK. Measurements were scanned from the corneal endothelium to the corneal surface with a Navis® software (NIDEK, Multi-Instrument Diagnostic System, Japan). Results Donor-receptor interface was found in an average of 114 ± 12.4 microns. Corneal stromal folds were observed from 111.1 ± 3.5 microns from the endothelium to 286 ± 94 microns (mean 175 ± 90.5 microns of the corneal stroma). Keratocites were activated in the donor tissue from 12 ± 1.4 microns from the endothelium to 105 ± 38.2 microns (mean 93 ± 36.9 microns of the corneal stroma). Conclusions Donor keratocites are activated up to 7 weeks after DSAEK. Several corneal folds are present in proximity to the donor-receptor interface after DSAEK. Further evaluation of these findings is justified to determine its clinical significance.

Organoids are complex three-dimensional in vitro organ-like model systems. Human organoids, which are derived from human pluripotent stem cells or primary human donor tissue, have been used to address fundamental questions about human development, stem cell biology and organ regeneration. Focus has now shifted towards implementation of organoids for biological discovery and advancing existing systems to more faithfully recapitulate the native organ. This work has highlighted significant unknowns in human biology and has invigorated new exploration into the cellular makeup of human organs during development and in the adult – work that is crucial for providing appropriate benchmarks for organoid systems. In this Review, we discuss efforts to characterize human organ cellular complexity and attempts to make organoid models more realistic through co-culture, transplantation and bioengineering approaches., Summary: This Review discusses the advances in human organoid technologies to improve organoid complexity, through co-culture, transplantation and bioengineering approaches.

BackgroundOptimizing the collagenase G (ColG):collagenase H (ColH) ratio is a key strategy for achieving tailored donor-tissue specific islet isolation. Collagen V (Col V) and collagen III (Col III) are crucial target matrices of ColG and ColH, respectively. We herein investigated the relevance between the expression of target matrices in pancreatic tissues and influence of ColG:ColH ratio on islet isolation outcome.MethodsIslet isolation was performed in Lewis and SD rats using different ColG:ColH ratios (5:1, 1:1 and 1:5; n = 7/group). The composition of Col III and Col V was examined using immunohistochemical staining, real-time polymerase chain reaction (PCR), Western blotting and mass spectrometry. Chain types in collagen I (Col I) were also assessed using mass spectrometry.ResultsNo beneficial effects were observed by increasing the ColG amount, irrespective of the rat strain. In contrast, the islet yield in Lewis rats was considerably increased by high amounts of ColH but decreased in SD rats, suggesting that Lewis pancreas contains more Col III than SD pancreas. Neither immunohistochemical nor real-time PCR showed correlation with isolation outcome. However, Western blotting revealed that Lewis contained considerably higher amount of Col III than SD (p = 0.10). Likewise, Col-I(α1)/Col-III(α1) and Col-I(α2)/Col-III(α1) were significantly lower in Lewis than in SD rats (p = 0.007, respectively). Furthermore, the isolation outcome was considerably correlated with the composition of homotrimeric Col I.ConclusionsThe Col III expression and the composition of homotrimeric Col I in pancreatic tissues determined using mass analyses appeared useful for optimizing the ColG:ColH ratio in islet isolation.