Long-Term Tissue Preservation at Ambient Temperature for Post-Mass Fatality Incident DNA-Based Victim Identification.

In a mass fatality incident (MFI), effective preservation of tissue samples is the cornerstone for downstream DNA-based identification of victims. This is commonly achieved through freezing of tissue samples excised from bodies/fragmented remains which may be buried or stored in refrigerated containers. This may, however, not be possible depending on the nature of the MFI; in particular, during armed conflict/war where extended periods of electrical outages would be expected. The present study compared the effectiveness of long-term tissue preservation at ambient temperatures using two commercial products (non-iodized kitchen salt and a 40% alcoholic beverage) against a chemical preservative (Allprotect™ Tissue Reagent (Qiagen, Germantown, MD, USA)) and freezing at -20 °C. Bovine muscle tissue, used as a proxy for human tissue, was treated with the four preservation methods and sampled at six different time-points over a 24-month period. All four methods were able to preserve the bovine tissue, generally yielding STR-PCR (Short Tandem Repeat-Polymerase Chain Reaction) amplicons > 200 bp in size even at the end of 24 months. Gel electrophoresis, however, indicated that salt was more effective in preserving DNA integrity with high-molecular-weight DNA clearly visible as compared to the low-molecular-weight DNA smears observed in the other methods. This study also proposes a simple process for the rapid and low-cost preservation of tissue samples for long-term storage at ambient temperatures in support of post-incident victim identification efforts.

Long-Term Results of the Linear Incision Technique With Tissue Reduction Versus Tissue Preservation for Inserting Bone-Anchored Hearing Implants: The Ongoing Optimization in Bone Implant Surgery.

OBJECTIVE: To compare the long-term outcomes of the linear incision technique with tissue reduction (LIT-TR) and the linear incision technique with tissue preservation (LIT-TP) for inserting bone-anchored hearing implants (BAHIs). STUDY DESIGN: Single-center retrospective cohort study. SETTING: Large general teaching hospital. PATIENTS: A total of 231 adult patients were included between August 2005 and October 2020, with a minimum follow-up time of 6 months. INTERVENTION: The test group received a BAHI using the LIT-TP (N = 147). The control group underwent surgery using the LIT-TR (N = 84). MAIN OUTCOME MEASURES: Soft tissue reactions, skin thickening, postoperative complications (e.g., wound dehiscence), and implant loss were compared between the test and control group. Furthermore, Cochlear Bone Anchored Solutions AB (Mölnlycke, Sweden) and Oticon Medical AB (Askim, Sweden) implants/abutments within the LIT-TP cohort were compared. Validated questionnaires were used to quantify patients' health-related quality of life (HRQoL). RESULTS: Significantly more cases with wound dehiscence and adverse soft tissue reactions (Holgers ≥2) were observed in the LIT-TR cohort (p < 0.001). However, the LIT-TP cohort showed significantly more cases with skin thickening (requiring treatment) within the first 2 years after implantation. There were no differences in implant loss rates, overall soft tissue reactions (Holgers >1), and overall HRQoL between the two patient groups. Significant improvement in the patients' HRQoL after implementation of a BAHI was found in both techniques. The Ponto Wide implant/abutment showed less frequent skin thickening (requiring treatment) and fewer soft tissue reactions compared with the BIA400 implant/abutment. CONCLUSION: This large-scale study demonstrates that the LIT-TP shows excellent long-term outcomes, including a low incidence of implant failure.

The Neuropeptide α-Melanocyte-Stimulating Hormone Prevents Persistent Corneal Edema following Injury.

Corneal endothelial cells (CEnCs) regulate corneal hydration and maintain tissue transparency through their barrier and pump function. However, these cells exhibit limited regenerative capacity following injury. Currently, corneal transplantation is the only established therapy for restoring endothelial function, and there are no pharmacologic interventions available for restoring endothelial function. This study investigated the efficacy of the neuropeptide α-melanocyte-stimulating hormone (α-MSH) in promoting endothelial regeneration during the critical window between ocular injury and the onset of endothelial decompensation using an established murine model of injury using transcorneal freezing. Local administration of α-MSH following injury prevented corneal edema and opacity, reduced leukocyte infiltration, and limited CEnC apoptosis while promoting their proliferation. These results suggest that α-MSH has a proregenerative and cytoprotective function on CEnCs and shows promise as a therapy for the prevention and management of corneal endothelial dysfunction.

Anatomical and Clinical Education in Physical and Occupational Therapy: Influence of Integration and Soft Preservation / Educación Anatómica y Clínica en Terapia Física y Ocupacional: Influencia de la Integración y la Preservación Blanda

SUMMARY: Anatomy and clinical skills are taught separately to physical and occupational therapy students. Formaldehyde is the primary chemical used to embalm donors which creates a challenge in integrating clinical skills into the anatomy curriculum. This study aimed to evaluate the integration of clinical skills into anatomical education using Imperial College London- Soft Preservation (ICL-SP) and formaldehyde embalming through the evaluation of student perceived learning and confidence. Students were invited to complete a survey after dissecting an ICL-SP and formaldehyde embalmed donors and perform clinical tests. It was easier to dissect and identify neurovascular structures on ICL-SP donors compared to formaldehyde. Clinical tests, like measuring range of motion and ligament tests were also more realistic on ICL-SP donors. The integration of clinical skills in the anatomical curriculum increased student perceived understanding of associated anatomy (p < 0.001), gave better understanding of how anatomy is important to their professions (p < 0.001) and increased motivation to learn anatomy (p < 0.001). The integration of clinical skills into anatomical education can facilitate student learning with higher confidence performing clinical skills and is complemented by the utilization of the new ICL-SP methodology instead of the traditional formaldehyde preservation.

Las habilidades anatómicas y clínicas se enseñan por separado a los estudiantes de terapia física y ocupacional. El formaldehído es el químico principal que se usa para embalsamar a los donantes, lo que crea un desafío para integrar las habilidades clínicas en el plan de estudios de anatomía. Este estudio tuvo como objetivo evaluar la integración de habilidades clínicas en la educación anatómica utilizando Imperial College London-Soft Preservation (ICL-SP) y embalsamamiento de formaldehído a través de la evaluación del aprendizaje y la confianza percibidos por los estudiantes. Se invitó a los estudiantes a completar una encuesta después de diseccionar un ICL-SP y donantes embalsamados formolizados y realizar pruebas clínicas. Fue más fácil diseccionar e identificar estructuras neurovasculares en donantes ICL-SP en comparación con los fijados en formaldehído. Las pruebas clínicas, como la medición del rango de movimiento y las pruebas de ligamentos, también fueron más realistas en los donantes de ICL-SP. La integración de habilidades clínicas en el plan de estudios anatómico aumentó la comprensión percibida por los estudiantes de anatomía asociada (p < 0,001), dio una mejor comprensión de cómo la anatomía es importante para sus profesiones (p < 0,001) y aumentó la motivación para aprender anatomía (p < 0,001). La integración de las habilidades clínicas en la educación anatómica puede facilitar el aprendizaje de los estudiantes con mayor confianza en el desempeño de las habilidades clínicas y se complementa con la utilización de la nueva metodología ICL-SP en lugar de la conservación tradicional con formaldehído.

Conservation of Organs (Heart, Brain and Kidney) of Canine by Cold-Temperature Silicone Plastination in an Animal Anatomy Laboratory in Ecuador / Conservación de Órganos (Corazón, Encéfalo y Riñón) de Canino Mediante la Técnica de Plastinación en Silicona al Frío Realizada en Laboratorio de Anatomía Animal en Ecuador

SUMMARY: For the purposes of teaching anatomy, the use of cadaver preparations is considered the most efficient way of ensuring that students retain knowledge. Nevertheless, in Ecuador the use of animal specimens in universities must comply with the internationally accepted principles of replacement, reduction and refinement (3Rs). Plastination is an alternative technique which allows organs to be conserved in the long term and complies with the 3Rs. The object of the present work was to use cold-temperature silicone plastination with Biodur® products to obtain long-lasting, easy-to-handle canine organs for use as tools for the teaching of animal anatomy. Six canine cadavers were obtained from local animal protection charities. The hearts, brains and kidneys of the cadavers were dissected and fixed with formaldehyde 10 %. They were then dehydrated with acetone at -20 °C. The specimens were impregnated with Biodur® S10:S3 (-20 °C) and finally cured with Biodur® S6. We plastinated six hearts, twelve kidneys, four brains and one encephalic slice of canine. The application of cold-temperature plastination to canine organs followed the parameters established for the conventional protocol, enabling us to obtain organs of brilliant appearance, free of odours, in which the anatomical form was preserved. Thus the technique helped us to comply with the 3Rs, as we obtained easy-to-handle teaching models to replace fresh or formaldehyde-fixed samples for the teaching-learning of the canine anatomy.

En la enseñanza de la Anatomía, el uso de preparaciones cadavéricas se considera el método que permite a los estudiantes retener el conocimiento de una forma más eficiente. No obstante, en Ecuador, el uso de especímenes animales en las universidades se debe realizar bajo el principio internacional de reemplazo, reducción y refinamiento (3Rs). La técnica de plastinación es una técnica alternativa que permite preservar órganos a largo plazo y que se adapta al principio de las 3Rs. El objetivo del trabajo fue utilizar la técnica de plastinación en silicona al frío con productos Biodur® para obtener órganos caninos duraderos y manejables útiles como herramienta para la enseñanza de la anatomía animal. Se obtuvieron seis cadáveres de caninos de fundaciones locales para la protección animal. Se realizaron disecciones de corazones, cerebros y riñones de los cadáveres caninos. Los órganos se fijaron con formalina al 10 %. A continuación, se llevó a cabo la deshidratación con acetona a -20 °C. Los especímenes fueron impregnados con S10:S3 Biodur® (-20 °C) y al final fueron curados con Biodur® S6. Se lograron plastinar seis corazones, doce riñones, cinco encéfalos y un tallo encefálico de canino. La técnica de plastinación al frío utilizada para obtener órganos de canino conservó los parámetros empleados en el protocolo convencional y permitió obtener órganos que presentaron aspecto brillante, ausencia de olores y mantuvieron la forma anatómica. Por lo que, la técnica facilitó cumplir con el principio de las 3Rs al obtenerse modelos didácticos fáciles de manipular que pueden reemplazar muestras frescas o formolizadas en el proceso de enseñanza-aprendizaje de la anatomía del canino.

A Novel Tissue Preservation and Transport Solution as a Substitute for Formalin.

Formalin, a common laboratory fixative, is a type 1 carcinogen; a biohazard with risks, environmental, disposal, and legal costs; and a chemical modifier of protein epitopes in tissues. A less-toxic tissue preservation method is therefore badly needed. We have developed a novel tissue preservation medium, Amber, composed of low-potassium dextran glucose, 10% honey, and 1% coconut oil. This study investigates Amber as compared with formalin with respect to the following aspects: (1) histologic preservation, (2) epitope integrity with immunohistochemistry (IHC) and immunofluorescence (IF), and (3) integrity of tissue RNA. Rat and human lung, liver, kidney, and heart tissues were collected and stored for 24 hours at 4 °C in Amber or formalin. The tissues were evaluated with hematoxylin and eosin; IHC: thyroid transcription factor, muscle-specific actin, hepatocyte-specific antigen, and common acute lymphoblastic leukemia antigen; and IF: VE-cadherin, vimentin, and muscle-specific actin. RNA quality upon extraction was also assessed. Amber demonstrated superior and/or noninferior performance in rat and human tissue evaluation with respect to standard techniques of histology, IHC, IF, and extracted RNA quality. Amber maintains high-quality morphology without compromising the ability to perform IHC and nucleic acid extraction. As such, Amber could be a safer and superior substitute to formalin for clinical tissue preservation for contemporary pathological examination.

Cardiac Transplantation: Physiology and Natural History of the Transplanted Heart.

Heart transplantation (HT) is one of the prodigious achievements in modern medicine and remains the cornerstone in the treatment of patients with advanced heart failure. Advances in surgical techniques, immunosuppression, organ preservation, infection control, and allograft surveillance have improved short- and long-term outcomes thereby contributing to greater clinical success of HT. However, prolonged allograft and patient survival following HT are still largely restricted by the development of late complications, including allograft rejection, infection, cardiac allograft vasculopathy (CAV), and malignancy. The introduction of mTOR inhibitors early after HT has demonstrated multiple protective effects against CAV progression, renal dysfunction, and tumorigenesis. Therefore, several HT programs increasingly use mTOR inhibitors with partial or complete withdrawal of calcineurin inhibitor (CNI) in stable HT patients to reduce complications risk and improve long-term outcomes. Furthermore, despite a substantial improvement in exercise capacity and health-related quality of life after HT as compared to advanced heart failure patients, most HT recipients remain with a 30% to 50% lower peak oxygen consumption (Vo 2 ) than that of age-matched healthy subjects. Several factors, including alterations in central hemodynamics, HT-related complications and alterations in the musculoskeletal system, and peripheral physiological abnormalities, presumably contribute to the reduced exercise capacity following HT. Cardiac denervation and subsequent loss of sympathetic and parasympathetic regulation are responsible for various physiological alterations in the cardiovascular system, which contributes to restricted exercise tolerance. Restoration of cardiac innervation may improve exercise capacity and quality of life, but the reinnervation process is only partial even several years after HT. Multiple studies have shown that aerobic and strengthening exercise interventions improve exercise capacity by increasing maximal heart rate, chronotropic response, and peak Vo 2 after HT. Novel exercise modalities, such as high-intensity interval training (HIT), have been proven as safe and effective for further improvement in exercise capacity, including among de novo HT recipients. Further developments have recently emerged, including donor heart preservation techniques, noninvasive CAV and rejection surveillance methods, and improvements in immunosuppressive therapies, all aiming at increasing donor availability and improving late survival after HT. © 2023 American Physiological Society. Compr Physiol 13:4719-4765, 2023.

Clinical efficacy of soft-tissue augmentation on tissue preservation at immediate implant sites: A randomized controlled trial.

AIM: This randomized controlled trial aimed to investigate the efficacy of soft-tissue augmentation (STA) with a subepithelial connective tissue graft (SCTG) or an acellular dermal matrix (ADM) on reducing tissue alterations at an immediate implant site. MATERIALS AND METHODS: This trial had three groups: (i) immediate implant with SCTG (ICT group); (ii) immediate implant with ADM (IAD group); (iii) immediate implant without STA (control group). Forty-six patients were randomly assigned to each group. Implants were placed at the maxillary anterior or premolar areas and restored after the 6-month visit. Clinical outcomes, including buccal soft-tissue contour, peri-implant mucosal level, soft-tissue thickness and keratinized tissue width, were measured at baseline and at 3-, 6- and 12-month follow-up visits. Radiographic bone levels were measured at baseline and at 6- and 12-month follow-up visits. Patient-reported outcomes were also collected. RESULTS: STA procedures increased peri-implant mucosal thickness and maintained buccal soft-tissue contours. Compared to the control group, STA groups did not prevent peri-implant mucosal recession or interproximal bone resorption. Generally, no significant differences in clinical outcomes were detected between the ICT and IAD groups. Most patients were highly satisfied with the immediate implant procedure and outcomes without significant differences between groups. CONCLUSIONS: STA at immediate implant sites enhanced soft-tissue thickness and maintained soft-tissue contours but did not prevent peri-implant mucosal recession or interproximal bone resorption. Long-term follow-up should be performed since these results were reported for only up to 1 year.

Investigation of the effects of subacromial bursal tissue preservation and microfracture procedure on healing after rotator cuff repair in a rat model.

INTRODUCTION: The aim of this study is to compare the preservation of bursal tissue and microfracture techniques and to examine the effectiveness of the combination of the two methods in rotator cuff tear healing in the rat shoulder. HYPOTHESIS: Bursal tissue preservation combined with microfracture is more effective in the rotator cuff repair. MATERIALS AND METHODS: Twenty-three male Sprague-Dawley rats were randomly divided into two groups. The bursal tissue was preserved in group 1 (n=11) and excised in group 2 (n=12). Groups were categorized into subgroups as L (left) and R (right) based on the shoulder side receiving microfracture (L received microfracture, R did not). Histopathological examination was performed using modified Bonar Score System. RESULTS: Cell morphology grades of group 1 were lower than group 2 (p<0.05). In terms of collagen measurements, the grade of group 1L (bursa preservation+microfracture) was lower than groups 1R, 2L, and 2R, and the grade of group 1R was lower than groups 2L and 2R. Cellularity grades of group 2 were higher than group 1 (p<0.05). Extracellular matrix grades of group 1 were lower than group 2 (p<0.05). The overall grades were lower in group 1 than in group 2 (p<0.05). DISCUSSION: Combined treatment of bursal tissue preservation and microfracture was the most efficient method as determined by healing findings in histopathological specimens. Preservation of bursal tissue was a more effective option in tendon healing than performing only microfracture. LEVEL OF PROOF: II, animal research.

Nanowarming and ice-free cryopreservation of large sized, intact porcine articular cartilage.

Successful organ or tissue long-term preservation would revolutionize biomedicine. Cartilage cryopreservation enables prolonged shelf life of articular cartilage, posing the prospect to broaden the implementation of promising osteochondral allograft (OCA) transplantation for cartilage repair. However, cryopreserved large sized cartilage cannot be successfully warmed with the conventional convection warming approach due to its limited warming rate, blocking its clinical potential. Here, we develope a nanowarming and ice-free cryopreservation method for large sized, intact articular cartilage preservation. Our method achieves a heating rate of 76.8 °C min-1, over one order of magnitude higher than convection warming (4.8 °C min-1). Using systematic cell and tissue level tests, we demonstrate the superior performance of our method in preserving large cartilage. A depth-dependent preservation manner is also observed and recapitulated through magnetic resonance imaging and computational modeling. Finally, we show that the delivery of nanoparticles to the OCA bone side could be a feasible direction for further optimization of our method. This study pioneers the application of nanowarming and ice-free cryopreservation for large articular cartilage and provides valuable insights for future technique development, paving the way for clinical applications of cryopreserved cartilage.

Variability in the Processing of Fresh Osteochondral Allografts.

The indications for fresh osteochondral allograft continue to increase. As a result, variations in graft processing and preservation methods have emerged. An understanding of these techniques is important when evaluating the optimal protocol for processing fresh osteochondral allografts prior to surgical implantation. The aim of this study is to review the literature and understand various tissue processing protocols of four leading tissue banks in the United States. Donor procurement, serological and microbiological testing, and storage procedures were compared among companies of interest. Similarities between the major tissue banks include donor screening, aseptic processing, and testing for microorganisms. Variability exists between these companies with relation to choice of storage media, antibiotic usage, storage temperature, and graft expiration dates. Potential exists for increased chondrocyte viability and lengthened time-to-expiration of the graft through a protocol of delicate tissue handling, proper choice of storage medium, adding hormones and growth factors like insulin growth factor-1 (IGF-1) to serum-free nutrient media, and storing these grafts closer to physiologic temperatures.

Exceptional soft tissue preservation reveals a cnidarian affinity for a Cambrian phosphatic tubicolous enigma.

Exoskeletal dwelling tubes are widespread among extant animals and early fossil assemblages. Exceptional fossils from the Cambrian reveal independent origins of tube dwelling by several clades including cnidarians, lophophorates, annelids, scalidophorans, panarthropods and ambulacrarians. However, most fossil tubes lack preservation of soft parts, making it difficult to understand their affinities and evolutionary significance. Gangtoucunia aspera (Wulongqing Formation, Cambrian Stage 4) was an annulated, gradually expanding phosphatic tube, with occasional attachments of multiple, smaller juveniles and has previously been interpreted as the dwelling tube of a 'worm' (e.g. a scalidophoran), lophophorate or problematicum. Here, we report the first soft tissues from Gangtoucunia that reveal a smooth body with circumoral tentacles and a blind, spacious gut that is partitioned by septa. This is consistent with cnidarian polyps and phylogenetic analysis resolves Gangtoucunia as a total group medusozoan. The tube of Gangtoucunia is phenotypically similar to problematic annulated tubular fossils (e.g. Sphenothallus, Byronia, hyolithelminths), which have been compared to both cnidarians and annelids, and are among the oldest assemblages of skeletal fossils. The cnidarian characters of G. aspera suggest that these early tubular taxa are best interpreted as cnidarians rather than sessile bilaterians in the absence of contrary soft tissue evidence.

Preserving the Phosphoproteome of Clinical Biopsies Using a Quick-Freeze Collection Device.

There is growing interest in proteomic analyses of tissue biopsies to reveal pathophysiology and identify biomarkers. The current gold standard for collecting tissue biopsies for preserving the proteome and post-translational modifications is flash freezing in liquid nitrogen (LN2). However, in many clinical settings, this is not an option due to unavailability of LN2 nor trained personnel for rapid biospecimen processing. To address this need, we developed a proof-of-concept quick-freeze prototype device to rapidly freeze biospecimens at the point-of-care to preserve the phosphoproteome without the need for LN2. Our objectives were to develop the device, demonstrate the ease of use, confirm the ability to ship through existing cold chain logistics, and evaluate the cooling performance (i.e., cool a tissue sample to <0°C in <60 seconds, below -8°C in <120 seconds, and maintain temperature <0°C for >60 minutes) in the context of preserving the proteome in a tissue biospecimen. To demonstrate feasibility, the performance of the prototype was benchmarked against flash freezing in LN2 using a murine melanoma patient-derived xenograft model subjected to total body irradiation to elicit phosphosignaling in the DNA damage response network. Tumors were harvested and quadrisected, with two parts of the tumor being snap frozen in LN2, and the remaining two parts being rapidly cooled in the prototype quick-freeze biospecimen containers. Phosphoproteins were profiled by liquid chromatography tandem mass spectrometry and quantified by targeted multiple reaction monitoring MS. Overall, the phosphoproteome was equivalent in biospecimens processed using the quick-freeze containers to those using the LN2 gold standard, although the measurements of a subset of phosphopeptides in the device-frozen specimens were more variable than LN2-frozen specimens. The prototype device forms the framework for development of a commercial device that will improve tissue biopsy preservation for measurement of important phosphosignaling molecules.

Biostratinomic alterations of an Edmontosaurus "mummy" reveal a pathway for soft tissue preservation without invoking "exceptional conditions".

Removal or protection from biostratinomic agents of decomposition, such as predators and scavengers, is widely seen as a requirement for high-quality preservation of soft tissues in the fossil record. In this context, extremely rapid burial is an oft-cited mechanism for shielding remains from degradation, but not all fossils fit nicely into this paradigm. Dinosaurian mummies in particular seemingly require two mutually exclusive taphonomic processes to preserve under that framework: desiccation and rapid burial. Here we present a recently prepared Edmontosaurus mummy that reveals an alternate fossilization pathway for resistant soft tissues (e.g., skin and nails). While the skin on this specimen is well-preserved in three dimensions and contains biomarkers, it is deflated and marked by the first documented examples of injuries consistent with carnivore activity on dinosaurian soft tissue during the perimortem interval. Incomplete scavenging of the carcass provided a route for the gases, fluids, and microbes associated with decomposition to escape, allowing more durable soft tissues to persist through the weeks to months required for desiccation prior to entombment and fossilization. This pathway is consistent with actualistic observations and explains why dinosaurian skin, while rare, is more commonly preserved than expected if extreme circumstances were required for its preservation. More broadly, our assumptions guide specimen collection and research, and the presence of soft tissues and biomolecules in fossils that demonstrably were not rapidly buried, such as this mummy, suggests that such types of evidence may be substantially more common than previously assumed.

Preservation of donor corneal epithelium in McCarey-Kaufman medium.

Purpose: To evaluate the role of McCarey-Kaufman (MK) medium in maintaining the integrity of donor corneal epithelium. Methods: Nineteen corneal buttons were harvested and stored in MK media at 2°C-8°C for four days. Serial photographs were done every day till the 3rd day, and images were then analyzed with ImageJ software (LOCI, University of Wisconsin, USA). The area of exposure and epithelial defect (ED) was calculated every day for each corneal button. Results: The average age of the donors was 56.5 ± 22.7 years and mean time from death to preservation of the corneal buttons was 7.7 ± 3.1 hours. The average corneal area was 145.6 ± 18.8 mm2. The total mean area of exposure was 3.6 ± 4.8, 7.2 ± 9.2, and 9.0 ± 11.9 mm2, and ED was 1.7 ± 4.6, 2.8 ± 5.3, and 3.3 ± 5.9 mm2 on days 1, 2, and 3, respectively. The percentage of increase in the area of exposure and ED in MK media was 3.71% and 1.1% from day 1 to day 3, respectively. Six out of 19 corneal buttons (31.57%) were utilized for keratoplasties, of which two were utilized in house and four were distributed outside. Of the two utilized corneas, none had epithelial defect on postoperative day 1. Rest 13 corneas were either used for training and research purposes, stored in glycerol media, or discarded. Conclusion: Since the percentage change in area of exposure/ED is not much at the end of day 3, corneas stored in MK media can be safely used even after three days of storage. Hence, MK medium serves as an excellent medium in maintaining the integrity of donor corneal epithelium.

Adipocere formation in biofilms as a first step in soft tissue preservation.

The preservation of soft tissue in the fossil record is mostly due to the replacement of organic structures by minerals (e.g. calcite, aragonite or apatite) called pseudomorphs. In rare cases soft tissues were preserved by pyrite. We assume that adipocere, as the shaping component, might be a preliminary stage in the pyritisation of soft tissues under anaerobic conditions. Using high-performance liquid chromatography coupled to ultraviolet and mass spectrometric detection (HPLC-UV/MS) and confocal Raman spectroscopy (CRS) we were able to demonstrate the transformation of the hepatopancreas (digestive gland) of the crayfish Cambarellus diminutus [Hobbs 1945] into adipocere within only 9 days, just inside a biofilm. Microorganisms (bacteria and fungi) which were responsible for the biofilm (Sphaerotilus [Kutzig 1833] and Pluteus [Fries 1857]) and maybe the adipocere formation (Clostridium [Prazmowski 1880]) were detected by 16S rRNA gene amplicon sequencing. Furthermore, micro-computed tomography (µ-CT) analyses revealed a precipitation of calcite and further showed that in animals with biofilm formation calcite precipitates in finer grained crystals than in individuals without biofilm formation, and that the precipitates were denser and replicated the structures of the cuticles better than the coarse precipitates.

Exceptional soft-tissue preservation of Jurassic Vampyronassa rhodanica provides new insights on the evolution and palaeoecology of vampyroteuthids.

Although soft tissues of coleoid cephalopods record key evolutionary adaptations, they are rarely preserved in the fossil record. This prevents meaningful comparative analyses between extant and fossil forms, as well as the development of a relative timescale for morphological innovations. However, unique 3-D soft tissue preservation of Vampyronassa rhodanica (Vampyromorpha) from the Jurassic Lagerstätte of La Voulte-sur-Rhône (Ardèche, France) provides unparalleled opportunities for the observation of these tissues in the oldest likely relative of extant Vampyroteuthis infernalis. Synchrotron X-ray microtomography and reconstruction of V. rhodanica allowed, for the first time, a high-resolution re-examination of external and internal morphology, and comparison with other fossil and extant species, including V. infernalis. The new data obtained demonstrate that some key V. infernalis characters, such as its unique type of sucker attachment, were already present in Jurassic taxa. Nonetheless, compared with the extant form, which is considered to be an opportunistic detritivore and zooplanktivore, many characters in V. rhodanica indicate a pelagic predatory lifestyle. The contrast in trophic niches between the two taxa is consistent with the hypothesis that these forms diversified in continental shelf environments prior to the appearance of adaptations in the Oligocene leading to their modern deep-sea mode of life.

Development and Characterization of a Nonelectronic Versatile Oxygenating Perfusion System for Tissue Preservation.

Oxygenated machine perfusion of human organs has been shown to improve both preservation quality and time duration when compared to the current gold standard: static cold storage. However, existing machine perfusion devices designed for preservation and transportation of transplantable organs are too complicated and organ-specific to merit use as a solution for all organs. This work presents a novel, portable, and nonelectronic device potentially capable of delivering oxygenated machine perfusion to a variety of organs. An innovative pneumatic circuit system regulates a compressed oxygen source that cyclically inflates and deflates silicone tubes, which function as both the oxygenator and perfusion pump. Different combinations of silicone tubes in single or parallel configurations, with lengths ranging from 1.5 to 15.2 m, were evaluated at varying oxygen pressures from 27.6 to 110.3 kPa. The silicone tubes in parallel configurations produced higher peak perfusion pressures (70% increase), mean flow rates (102% increase), and oxygenation rates (268% increase) than the single silicone tubes that had equivalent total lengths. While pumping against a vascular resistance element that mimicked a kidney, the device achieved perfusion pressures (8.4-131.6 mmHg), flow rates (2.0-40.2 mL min-1), and oxygenation rates (up to 388 µmol min-1) that are consistent with values used in previous kidney preservation studies. The nonelectronic device achieved those perfusion parameters using 4.4 L min-1 of oxygen to operate. These results demonstrate that oxygenated machine perfusion can be successfully achieved without any electronic components.

Preservation of Adrenoceptor and Endothelin Receptor Mediated Vasoconstriction and of Endothelium-Dependent Relaxation after Cold Storage of Explanted Blood Vessels for ex vivo Analyses.

INTRODUCTION: Adrenoceptor and endothelin (ET) receptor-mediated vasoconstriction as well as endothelium-dependent vasodilation of human saphenous veins were compared before and after 20 h of cold storage. METHODS: Contractile responses to potassium chloride (KCl), norepinephrine (NE), and ET-1 as well as vasodilator responses to acetylcholine (ACh) were evaluated. RESULTS: Storage in HEPES-supplemented Dulbecco's modified Eagle's medium (HDMEM) diminished KCl induced contractile forces to 71% (p = 0.002) and NE induced contractions to 80% (p = 0.037), in contrast to HEPES-supplemented Krebs-Henseleit solution (HKH) and TiProtec solution. KCl-normalized NE contractions were not affected by storage. NE EC50 values were slightly lower (7.1E-8 vs. 7.5E-8, p = 0.019) after storage in HKH, with no changes after storage in the other solutions. Endothelium-dependent responses to ACh were not affected by storage. ET-1 induced contractions were attenuated after storage in HDMEM (77%, p = 0.002), HKH (75%, p = 0.020), and TiProtec (73%, p = 0.010) with no changes in normalized constrictions. ET-1 EC50 values were not affected by storage. CONCLUSION: Loss of contractility after storage in HDMEM may reflect the lower content of dextrose. There was no specific attenuation of adrenoceptor, ET-receptor, or ACh receptor mediated signal transduction after storage in any of the media. HKH or TiProtec are equally suitable cold storage solutions for ex vivo measurements.

Comparación de resultados entre soluciones con y sin formol como medios de fijación y conservación en corazones de Gallus gallus domesticus / Comparison of results between solutions with and without formaldehyde as means of fixation and conservation in Gallus gallus domesticus hearts

RESUMEN: La solución de formol es utilizada en las Escuelas de medicina como medio de fijación y conservación de cadáveres para el estudio de la Anatomía, a la que están expuestos estudiantes, técnicos y personal docente; es alergénica e irritante a las mucosas, y reconocida carcinogénica en humanos por International Agency for Research on Cancer (2006). El objetivo del presente estudio fue comparar resultados cuantitativos y cualitativos entre corazones de Gallus gallus domesticus, luego de aplicarles soluciones con y sin formol. Se formaron dos grupos al azar, a uno se le aplicó solución de formol al 10 %, y al otro solución libre de formol. Se realizaron medidas antropométricas, organolépticas, y de fotografía (Pretest, durante y Postest). Se elaboró base datos en Microsoft Excel (2019), y su procesamiento en SPSS Statistics 2017 Versión 25. Para variables cuantitativas se aplicó la prueba de Shapiro-Wilk, y t-Student pareada. Para variables cualitativas el test Alfa de Cronbach, Chi cuadrado (X2) y los correspondientes coeficientes de asociación (D de Somers y Tau b de Kendal). Los resultados obtenidos de las variables peso, largo, y altura presentaron diferencia estadística significativa (p-valor <0,05), siendo diferente para el ancho y grosor de la pared del ventrículo izquierdo. Las variables color y consistencia presentaron diferencias significativa (p-valor <0,05). El olor irritante a las mucosas estuvo presente durante todo el estudio con la solución con formol. A la inspección, ninguno de los dos grupos presento colonización - descomposición. Se concluye que, los órganos en experimentación que se les aplicó solución libre de formol, presentaron mejores resultados con respecto a los que se les aplico formol al 10 %.

SUMMARY: The formaldehyde solution is used in medical schools as a means of fixing and preserving corpses for the study of Anatomy, to which students, technicians and teaching personnel are exposed; it is allergenic and irritant to the mucosa, and recognized as a human carcinogen by the International Agency for Research on Cancer (2006). The objective of the present study was to compare quantitative and qualitative results between Gallus gallus domesticus hearts, after applying solutions with and without formaldehyde. Two groups were formed at random, to one a 10 % formaldehyde solution was applied, and to the other formaldehyde- free solution. Anthropometric, organoleptic, and photographic measurements were carried out (Pretest, during and Posttest). A database was prepared in Microsoft Excel (2019), and its processing in SPSS Statistics 2017 Version 25. For quantitative variables, the Shapiro-Wilk test and t-Student paired were applied. For qualitative variables the Cronbach's Alpha test, Chi square (X2) and the corresponding association coefficients (Somers D and Kendal's Tau b). The results obtained from the variables weight, length, and height presented a statistically significant difference (p-value <0.05), being different for the width and thickness of the left ventricular wall. The variables color and consistency showed significant differences (p-value <0.05). The irritating smell to the mucous membranes was present throughout the study with the formaldehyde solution. Upon inspection, neither group showed colonization - decomposition. It is concluded that the organs in experimentation that were applied formaldehyde-free solution presented better results compared to those that were applied 10 % formaldehyde.