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1.
Cornea ; 41(4): 470-477, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35244627

RESUMO

PURPOSE: The aim of this study was to explore the optimal method of small-incision lenticule extraction (SMILE)-derived lenticules, subjected to long-term preservation using glycerol, under a range of temperatures, and using an array of dehydration agents. METHODS: In total, 108 myopic lenticules were collected from patients undergoing the SMILE procedure. Fresh lenticules served as a control group for this study, whereas all other lenticules were separated into 8 groups, which were preserved at 4 different temperatures (room temperature [RT], 4, -20, and -80°C) with or without silica gel in anhydrous glycerol. Evaluated parameters included thickness, transmittance, hematoxylin and eosin staining, transmission electron microscopy, and immunohistochemistry analyses. RESULTS: After a 3-month preservation period, lenticular thickness in these different groups was significantly increased, particularly for samples stored at RT. The mean percentage transmittance of lenticules stored at -80°C with or without silica gel was closest to that of fresh lenticules. Hematoxylin and eosin staining revealed sparsely arranged collagen fibers that were more scattered in preserved lenticules relative to fresh lenticules, particularly in RT samples. Transmission electron microscopy revealed that the fibril bundles densities in lenticules stored at RT were significantly less than those stored at other temperatures. Immunohistochemistry analyses revealed reductions in or loss of CD45 and human leukocyte antigens in all preserved lenticules relative to control samples. CONCLUSIONS: Of the tested approaches, the preservation of SMILE-derived lenticules over a 3-month period was optimal at -80°C with or without silica gel in anhydrous glycerol.


Assuntos
Substância Própria/efeitos dos fármacos , Cirurgia da Córnea a Laser/métodos , Crioprotetores/farmacologia , Dessecação/métodos , Glicerol/farmacologia , Miopia/cirurgia , Temperatura , Adulto , Substância Própria/fisiologia , Antígenos HLA/metabolismo , Antígenos HLA-DR/metabolismo , Humanos , Antígenos Comuns de Leucócito/metabolismo , Microscopia Eletrônica de Transmissão , Preservação de Tecido/métodos , Coleta de Tecidos e Órgãos
2.
Clin Exp Dent Res ; 8(1): 9-19, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35018724

RESUMO

OBJECTIVES: To investigate if the application of the granulation tissue preservation technique (GTPT) in regenerative therapy of infrabony periodontal defects results in more clinical attachment level (CAL) gain and more radiographic bone gain (RBG) than the conventional resective approach 12 months after surgery. MATERIALS AND METHODS: Forty patients exhibiting at least one infrabony defect with a probing pocket depth (PPD) ≥6 mm and a radiographic infrabony component (INFRAX-ray ) ≥3 mm were randomly treated with the GTPT (test group) or the double-flap approach with resection of the defect-filling granulation tissue (control group). Enamel matrix derivatives were applied in both groups. Clinical and radiographic parameters were recorded at baseline (t0), 6 months (t1), and 12 months (t2) after surgery. The primary outcome variable was CAL gain between t0 and t2. RESULTS: When all patients were considered, ΔCALt0-t2 did not differ significantly between the two groups (p = .160). Significant PPD reduction (test group: 4.38 ± 1.36 mm; control group: 4.06 ± 2.38 mm), CAL gain (test group: 3.75 ± 1.24 mm; control group: 2.88 ± 2.09 mm), and RBG (test group: 3.06 ± 1.74 mm; control group: 3.27 ± 2.19 mm) were achieved at t2 in both groups. Using multivariate linear regression, PPDt0 and group were identified as variables with the greatest influence on ΔCALt0-t2 . PPDt0 and INFRAX-ray were identified as variables with the greatest influence on RBGt0-t2 . Patients with a defect angle >22° showed significantly more CAL gain in the test group (t0-t1: 3.08 ± 1.38 mm; t0-t2: 3.62 ± 0.96 mm) than in the control group (t0-t1: 1.77 ± 1.54 mm; t0-t2: 2.18 ± 1.83 mm). CONCLUSIONS: Regarding all patients, the study failed to show significant differences between the test and control groups. However, the GTPT appears to lead to more CAL gain in noncontaining infrabony defects.


Assuntos
Procedimentos Cirúrgicos Bucais , Tuberculina , Regeneração Tecidual Guiada Periodontal/métodos , Humanos , Preservação de Tecido
3.
World Neurosurg ; 161: e61-e74, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35032716

RESUMO

BACKGROUND: Glioblastoma (GB) is an aggressive tumor showing extensive intertumoral and intratumoral heterogeneity. Several possible reasons contribute to the historical inability to develop effective therapeutic strategies for treatment of GB. One such challenge is the inability to consistently procure high-quality biologically preserved specimens for use in molecular research and patient-derived xenograft model development. No scientifically derived standardized method exists for intraoperative tissue collection specifically designed with the fragility of RNA in mind. METHODS: In this investigation, we set out to characterize matched specimens from 6 GB patients comparing the traditional handling and collection processes of intraoperative tissue used in most neurosurgical operating rooms versus an automated resection, collection, and biological preservation system (APS) which captures, preserves, and biologically maintains tissue in a prescribed and controlled microenvironment. Matched specimens were processed in parallel at various time points and temperatures, evaluating viability, RNA and protein concentrations, and isolation of GB cell lines. RESULTS: We found that APS-derived GB slices stored in an APS modified medium remained viable and maintained high-quality RNA and protein concentration for up to 24 hours. CONCLUSIONS: Our results showed that primary GB cell cultures derived in this manner had improved growth over widely used collection and preservation methods. By implementing an automated intraoperative system, we also eliminated inconsistencies in methodology of tissue collection, handling and biological preservation, establishing a repeatable and standardized practice that does not require additional staff or a laboratory technician to manage it.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/cirurgia , Glioblastoma/patologia , Glioblastoma/cirurgia , Humanos , Projetos Piloto , Preservação Biológica , RNA , Preservação de Tecido/métodos , Microambiente Tumoral
4.
Burns ; 48(2): 390-395, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34670715

RESUMO

INTRODUCTION: Glycerol-preserved skin allograft (GPA) plays a vital role, especially in the management of burns injury. Where it is utilized as temporary wound closure, the considerably cost-effective, simpler handling and storage of GPA makes it preferable in almost all clinical indications. The GPA was first introduced to the Hospital Universiti Sains Malaysia in 2001. The supply was imported from Euro Skin Bank, Beverwijk, The Netherlands. In the year 2013, our center had started maintaining an in-house glycerolized skin bank. METHOD: We preserved donor skin grafts from patients who underwent plastic surgery-related procedures in 85% glycerol and stored them at +2 °C to +10 °C. Cost estimation of the GPA per cm2 was calculated to analyze the effectiveness of its preservation technique. RESULTS: The cost of GPA from our skin bank is estimated to be almost 90% reduction in cost as compared to the supply from Euro Skin Bank. CONCLUSION: The selective and strategic use of the GPA in major burn patients assure effective advantages in the treatment of burns. The clinical significance of skin allograft usage is very high. The cost-effectiveness of maintaining an in-house skin bank made it possible for various centers for skin allograft usage.


Assuntos
Queimaduras , Glicerol , Queimaduras/cirurgia , Análise Custo-Benefício , Humanos , Pele , Transplante de Pele/métodos , Preservação de Tecido/métodos
5.
Geobiology ; 20(3): 377-398, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34747129

RESUMO

Determining how soft tissues are preserved and persist through geologic time are continuing challenge because decay begins immediately after senescence while diagenetic transformations generally progress over days to millions of years. However, in recent years, carbonate concretions containing partially-to-fully decayed macroorganisms have proven to be remarkable windows into the diagenetic continuum revealing insights into the fossilization process. This is because most concretions are the result of biologically induced mineral precipitation caused by the localized decay of organic matter, which oftentimes preserves a greater biological signal relative to their host sediment. Here we present a comparative lipid biomarker study investigating processes associated with soft-tissue preservation within Holocene-age carbonate concretions that have encapsulated modern capelin (Mallotus villosus). We focus on samples collected from two depositional settings that have produced highly contrasting preservation end-members: (1) Kangerlussuaq, Greenland: a marine environment, which, due to isostatic rebound, has exposed strata containing concretions exhibiting exceptional soft-tissue preservation (6-7 kya), and (2) Greens Creek, Ottawa, Canada: a paleo brackish-to-freshwater marine excursion containing concretions exhibiting skeletal remains (~11 kya). Lipid biomarker analysis reveals endogenous capelin tissues and productive waters at Kangerlussuaq that are in sharp contrast to Greens Creek concretions, which lack appreciable capelin and environmental signals. Comparable distributions of bacterial fatty acids and statistical analyses suggest soft-tissue preservation within concretions is agnostic to specific heterotrophic decay communities. We, therefore, interpret preservation within carbonate concretions may represent a race between microbially induced authigenic precipitation and decay. Namely, factors resulting in exceptional preservation within concretions likely include: (1) organic matter input, (2) rate of decay, (3) carbonate saturation, (4) porewater velocity, and (5) rate of authigenic (carbonate) precipitation resulting in arrested decay/bacterial respiration due to cementing pore spaces limiting the diffusion of electron acceptors into the decay foci.


Assuntos
Carbonatos , Geologia , Bactérias , Carbonatos/análise , Lipídeos , Minerais/análise , Preservação de Tecido
6.
Microsurgery ; 42(3): 265-270, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33580739

RESUMO

The thigh region is often site of soft tissue tumors development. Leiomyosarcoma, in particular, is a malignant tumor that, if not promptly treated, presents a growth rate that often results in large masses. The safest treatment in these cases is margin-free extensive surgical resection. This leads to rather large defects that in a delicate region, such as the medial thigh, implies a series of possible complications from the lymphatic point of view. In this region run major lymphatic vessels, appointed to drain the whole leg. Now that one is aware of this issue, the best solution is trying to obtain an efficient reconstruction and preventing the development of postoperative lymphedema and lymphocele. Here, we present a case of great saphenous vein leiomyosarcoma resection in the right medial thigh reconstructed by means of two superficial circumflex iliac artery perforator (SCIP) flaps with lymphatic tissue preservation, combined with preventive lymphovenous anastomosis (LVA). A 67-years-old woman presented a 22 × 16 cm soft tissue defect after the surgical excision. To fill the defect, we resorted to a larger SCIP flap island, supplied by both the superficial and deep branches of the superficial circumflex iliac artery anastomosed in perforator-to-perforator fashion, and to a smaller SCIP flap island supplied only by the superficial branch. Before surgery, the lymphatic vessels running in the flaps area were identified with indocyanine green lymphography and were carefully preserved during the harvest procedure. They were then transferred with the surrounding tissue and orientated in order to match the lymphatic flow direction, providing further fluid drainage. To boost the lymphatic drainage, an LVA was also performed at the superior-edge-of-the-knee incision point joining a functioning lymphatic vessel to a nearby reflux-free vein. The postoperative course was uneventful and at 7 months follow-up, the patient showed good cosmetic and functional outcomes with no swelling and no signs of tumor relapse. This report provides a series of technical insights and adds further evidence to support the efficacy of this procedure for management of soft tissue defects in the medial thigh region.


Assuntos
Vasos Linfáticos , Retalho Perfurante , Procedimentos Cirúrgicos Reconstrutivos , Idoso , Anastomose Cirúrgica , Feminino , Humanos , Artéria Ilíaca/cirurgia , Vasos Linfáticos/cirurgia , Recidiva Local de Neoplasia/cirurgia , Retalho Perfurante/irrigação sanguínea , Procedimentos Cirúrgicos Reconstrutivos/métodos , Coxa da Perna/cirurgia , Preservação de Tecido
7.
J Orthop Surg (Hong Kong) ; 29(3): 23094990211061249, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34893002

RESUMO

PURPOSE: We have previously described anterior cruciate ligament reconstruction with a rounded rectangular femoral tunnel created using a rounded rectangular dilator designed to enable a more anatomical and wider tendon-bone junction. However, the influence of remnant tissue preservation on the creation of the rounded rectangular femoral tunnel is not clear. This study aimed to evaluate the influence of remnant tissue preservation on the creation of the rounded rectangular femoral tunnel. METHODS: A total of 198 patients who underwent primary anterior cruciate ligament reconstruction with a rounded rectangular femoral tunnel were evaluated retrospectively. Patients were categorized into a remnant preservation group (group P) and a non-preservation group (group N). Computed tomography images taken 1 week postoperatively were analyzed. The location of the rounded rectangular femoral tunnel evaluated using the quadrant method, its rotation angle, and the graft bending angle were compared between the two groups. The differences and the variance in femoral tunnel assessment were compared using the two-sample t-test and Levene's test. RESULTS: Although there was no significant difference in the location of femoral tunnel for the deep/shallow direction along the Blumensaat's line (difference, p = .326; variances, p = .970), the tunnel was significantly lower in group P than in group N, with no variances (difference, p = .001; variances, p = .326). There were no significant differences and no variances in the tunnel rotation angle and the graft bending angle (difference, p = .727 and 0.514, respectively; variances, p = .827 and .445, respectively). Blow out of the posterior wall of the medial aspect of the femoral lateral condyle was an intraoperative complication that occurred in one case in group N. CONCLUSION: The remnant preservation approach creates a lower femoral tunnel compared to the non-preservation technique. However, a rounded rectangular femoral tunnel can be created safely and is reproducible with remnant tissue preservation.


Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior/métodos , Fêmur/cirurgia , Humanos , Estudos Retrospectivos , Preservação de Tecido
8.
Reprod Biol ; 21(4): 100575, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34808453

RESUMO

Cryopreservation and transplantation of ovarian tissue are proposed methods for the restoration of endocrine function and reproductive potential. Therefore, this study aimed to evaluate the effects of vitrification and xenotransplantation on follicle viability, activation, stromal cell integrity, vascularization, and micronuclei formation. Bovine fetal ovaries were fragmented and assigned to the following groups: Fresh control (FC), ovarian fragments immediately fixed; Vitrified control (VC), ovarian fragments vitrified; Vitrified xenotransplanted (VX), ovarian fragments vitrified and xenotransplanted; and Fresh xenotransplanted (FX), ovarian fragments xenotransplanted. Ovarian fragments were grafted in female BALB/c mice and recovered after 14 days. Follicular viability was preserved (P > 0.05) in VC group. The rate of developing follicles was greater (P < 0.05) in the FX group compared to other groups. Follicular density was higher (P < 0.05) in the VC group than the FC, VX, and FX groups. A decrease (P < 0.05) of stromal cell density was recorded after vitrification (VC vs. FX). Blood vessel density decreased in VC, VX, and FX groups compared with the FC group, and blood vessel density was correlated with follicular viability (positively; P = 0.07) and developing follicles (negatively; P < 0.001). Both vitrification and xenotransplantation groups (VC, VX, and FX) had a greater (P < 0.05) number of cells with one MN compared to the FC group. In summary, our findings showed that both vitrification and xenotransplantation modified blood vessel, follicular and stromal cell densities, follicular viability and activation, and micronuclei formation in ovarian tissue.


Assuntos
Criopreservação/veterinária , Ovário/fisiologia , Preservação de Tecido/veterinária , Transplante Heterólogo/veterinária , Animais , Bovinos , Feminino , Feto , Camundongos , Camundongos Endogâmicos BALB C , Gravidez , Preservação de Tecido/métodos , Vitrificação
9.
Biomed Pharmacother ; 143: 112237, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34649361

RESUMO

Intestinal transplantation has become an established therapeutic option that provides improved quality of life to patients with end-stage intestinal failure when total parenteral nutrition fails. Whereas this challenging life-saving intervention has shown exceptional growth over the past decade, illustrating the evolution of this complex and technical procedure from its preclinical origin in the mid-20th century to become a routine clinical practice today with several recent innovations, its success is hampered by multiple hurdles including technical challenges such as surgical manipulation during intestinal graft procurement, graft preservation and reperfusion damage, resulting in poor graft quality, graft rejection, post-operative infectious complications, and ultimately negatively impacting long-term recipient survival. Therefore, strategies to improve current intestinal transplantation protocol may have a significant impact on post-transplant outcomes. Carbon monoxide (CO), previously considered solely as a toxic gas, has recently been shown to be a physiological signaling molecule at low physiological concentrations with therapeutic potentials that could overcome some of the challenges in intestinal transplantation. This review discusses recent knowledge about CO in intestinal transplantation, the underlying molecular mechanisms of protection during intestinal graft procurement, preservation, transplantation and post-transplant periods. A section of the review also discusses clinical translation of CO and its challenges in the field of solid organ transplantation.


Assuntos
Monóxido de Carbono/uso terapêutico , Isquemia Fria , Intestinos/transplante , Soluções para Preservação de Órgãos/uso terapêutico , Transplante de Órgãos , Traumatismo por Reperfusão/prevenção & controle , Preservação de Tecido , Animais , Monóxido de Carbono/efeitos adversos , Monóxido de Carbono/metabolismo , Isquemia Fria/efeitos adversos , Difusão de Inovações , Sobrevivência de Enxerto , Humanos , Intestinos/metabolismo , Intestinos/patologia , Soluções para Preservação de Órgãos/efeitos adversos , Soluções para Preservação de Órgãos/metabolismo , Transplante de Órgãos/efeitos adversos , Segurança do Paciente , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Medição de Risco , Fatores de Risco , Resultado do Tratamento
10.
Am J Physiol Lung Cell Mol Physiol ; 321(6): L1023-L1035, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34643087

RESUMO

Precision-cut lung slices (PCLS) are used as ex vivo model of the lung to fill the gap between in vitro and in vivo experiments. To allow optimal utilization of PCLS, possibilities to prolong slice viability via cold storage using optimized storage solutions were evaluated. Rat PCLS were cold stored in DMEM/F-12 or two different preservation solutions for up to 28 days at 4°C. After rewarming in DMEM/F-12, metabolic activity, live/dead staining, and mitochondrial membrane potential was assessed to analyze overall tissue viability. Single-cell suspensions were prepared and proportions of CD45+, EpCAM+, CD31+, and CD90+ cells were analyzed. As functional parameters, TNF-α expression was analyzed to detect inflammatory activity and bronchoconstriction was evaluated after acetylcholine stimulus. After 14 days of cold storage, viability and mitochondrial membrane potential were significantly better preserved after storage in solution 1 (potassium chloride rich) and solution 2 (potassium- and lactobionate-rich analog) compared with DMEM/F-12. Analysis of cell populations revealed efficient preservation of EpCAM+, CD31+, and CD90+ cells. Proportion of CD45+ cells decreased during cold storage but was better preserved by both modified solutions than by DMEM/F-12. PCLS stored in solution 1 responded substantially longer to inflammatory stimulation than those stored in DMEM/F-12 or solution 2. Analysis of bronchoconstriction revealed total loss of function after 14 days of storage in DMEM/F-12 but, in contrast, a good response in PCLS stored in the optimized solutions. An improved base solution with a high potassium chloride concentration optimizes cold storage of PCLS and allows shipment between laboratories and stockpiling of tissue samples.


Assuntos
Temperatura Baixa , Criopreservação/métodos , Pulmão/fisiologia , Potencial da Membrana Mitocondrial , Soluções para Preservação de Órgãos/química , Preservação de Tecido/métodos , Sobrevivência de Tecidos , Animais , Masculino , Ratos , Ratos Wistar
11.
Placenta ; 115: 115-120, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34600275

RESUMO

INTRODUCTION: To investigate the role of placental extracellular vesicles (EVs), especially in pathological pregnancy, the use of freshly isolated EVs is often limited due to the sporadic and unpredictable availability of placental samples. Therefore, it is important to understand and use optimised storage conditions for placental EVs. In this study, we investigated different conditions for the short-term storage of placental micro- and nano-EVs and examined their biological activity. METHODS: Placental EVs were collected from first trimester placentae. EVs were suspended in PBS and aliquoted, and then stored for up to 14 days at room temperature, 4 °C or -20 °C. Total protein and DNA levels were measured at various time points. The ability of stored placental EVs to alter endothelial cell activation was quantified by monocyte adhesion assays. RESULTS: There was no difference in the concentration of placental micro- or nano-EVs between each time point, when stored at either room temperature or 4 °C. However, there was a significant loss of placental EVs after storage at -20 °C. There was no difference in protein or DNA levels of placental EVs when stored at either room temperature or 4 °C. Biological activity of placental EVs was retained for up to 14 days at either room temperature or 4 °C measured by monocyte adhesion assays. DISCUSSION: We have shown that placental micro- and nano-EVs are stable and retain biological activities following storage in PBS or media for 14 days at either room temperature or 4 °C.


Assuntos
Vesículas Extracelulares/fisiologia , Placenta/ultraestrutura , Preservação de Tecido/métodos , Micropartículas Derivadas de Células/fisiologia , Feminino , Idade Gestacional , Humanos , Gravidez , Temperatura , Fatores de Tempo
12.
Pathol Int ; 71(11): 725-740, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34614280

RESUMO

Clinical cancer genomic testing based on next-generation sequencing can help select genotype-matched therapy and provide diagnostic and prognostic information. Pathological tissue from malignant tumors obtained during routine practice are frequently used for genomic testing. This article is aimed to standardize the proper handling of pathological specimens in practice for genomic medicine based on the findings established in "Guidelines on the handling of pathological tissue samples for genomic medicine (in Japanese)" published by The Japanese Society of Pathology (JSP) in 2018. The two-part practical guidelines are based on empirical data analyses; Part 1 describes the standard preanalytic operating procedures for tissue collection, processing, and storage of formalin-fixed paraffin-embedded (FFPE) samples, while Part 2 describes the assessment and selection of FFPE samples appropriate for genomic testing, typically conducted by a pathologist. The guidelines recommend that FFPE sample blocks be used within 3 years from preparation, and the tumor content should be ≥30% (minimum 20%). The empirical data were obtained from clinical studies performed by the JSP in collaboration with leading Japanese cancer genome research projects. The Japanese Ministry of Health, Labour, and Welfare (MHLW) recommended to comply with the JSP practical guidelines in implementing cancer genomic testing under the national health insurance system in over 200 MHLW-designated core and cooperative cancer genome medicine hospitals in Japan.


Assuntos
Testes Genéticos/normas , Genômica/normas , Neoplasias/genética , Neoplasias/patologia , Manejo de Espécimes/normas , Testes Genéticos/métodos , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Japão , Manejo de Espécimes/métodos , Preservação de Tecido/métodos , Preservação de Tecido/normas
13.
Hum Brain Mapp ; 42(18): 5956-5972, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34541735

RESUMO

Formalin fixation has been shown to substantially reduce T2 estimates, primarily driven by the presence of fixative in tissue. Prior to scanning, post-mortem samples are often placed into a fluid that has more favourable imaging properties. This study investigates whether there is evidence for a change in T2 in regions close to the tissue surface due to fixative outflux into this surrounding fluid. Furthermore, we investigate whether a simulated spatial map of fixative concentration can be used as a confound regressor to reduce T2 inhomogeneity. To achieve this, T2 maps and diffusion tensor estimates were obtained in 14 whole, formalin-fixed post-mortem brains placed in Fluorinert approximately 48 hr prior to scanning. Seven brains were fixed with 10% formalin and seven brains were fixed with 10% neutral buffered formalin (NBF). Fixative outflux was modelled using a proposed kinetic tensor (KT) model, which incorporates voxelwise diffusion tensor estimates to account for diffusion anisotropy and tissue-specific diffusion coefficients. Brains fixed with 10% NBF revealed a spatial T2 pattern consistent with modelled fixative outflux. Confound regression of fixative concentration reduced T2 inhomogeneity across both white and grey matter, with the greatest reduction attributed to the KT model versus simpler models of fixative outflux. No such effect was observed in brains fixed with 10% formalin. Correlations between the transverse relaxation rate R2 and ferritin/myelin proteolipid protein (PLP) histology lead to an increased similarity for the relationship between R2 and PLP for the two fixative types after KT correction.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Imagem de Tensor de Difusão/métodos , Modelos Teóricos , Preservação de Tecido , Diagnóstico , Fixadores , Formaldeído , Humanos
14.
Artigo em Inglês | MEDLINE | ID: mdl-34547079

RESUMO

Conventional crestal and intrasulcular incisions followed by full-thickness flap reflection may inevitably induce surgical trauma, resulting in facial contour reduction, mucosal recession, and interdental papilla loss. Flapless implant surgery is the most conservative approach; however, it might create undetectable bone fenestration/dehiscence and subsequent complications. The present clinical study introduces a modified and minimally invasive approach, the palatal access flap (PAF), for placing implants in the esthetic zone. Preliminary data of 15 consecutive cases demonstrated clinically negligible soft tissue contour changes when pre- and postoperative 3D model scans were compared. The PAF technique could be a surgical solution, especially for patients with a high esthetic risk, to maintain facial and interproximal tissue contours for the implant site and adjacent teeth.


Assuntos
Implantes Dentários para Um Único Dente , Implantes Dentários , Implantação Dentária Endo-Óssea , Estética Dentária , Humanos , Estudos Retrospectivos , Preservação de Tecido
15.
Commun Biol ; 4(1): 1118, 2021 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-34552201

RESUMO

Low-temperature biopreservation and 3D tissue engineering present two differing routes towards eventual on-demand access to transplantable biologics, but recent advances in both fields present critical new opportunities for crossover between them. In this work, we demonstrate sub-zero centigrade preservation and revival of autonomously beating three-dimensional human induced pluripotent stem cell (hiPSC)-derived cardiac microtissues via isochoric supercooling, without the use of chemical cryoprotectants. We show that these tissues can cease autonomous beating during preservation and resume it after warming, that the supercooling process does not affect sarcomere structural integrity, and that the tissues maintain responsiveness to drug exposure following revival. Our work suggests both that functional three dimensional (3D) engineered tissues may provide an excellent high-content, low-risk testbed to study complex tissue biopreservation in a genetically human context, and that isochoric supercooling may provide a robust method for preserving and reviving engineered tissues themselves.


Assuntos
Temperatura Baixa , Coração/fisiologia , Preservação de Tecido/métodos , Humanos
16.
Nat Biomed Eng ; 5(8): 793-804, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34426675

RESUMO

The three classical core technologies for the preservation of live mammalian biospecimens-slow freezing, vitrification and hypothermic storage-limit the biomedical applications of biospecimens. In this Review, we summarize the principles and procedures of these three technologies, highlight how their limitations are being addressed via the combination of microfabrication and nanofabrication, materials science and thermal-fluid engineering and discuss the remaining challenges.


Assuntos
Manejo de Espécimes/métodos , Preservação de Tecido/métodos , Animais , Congelamento , Humanos , Hidrogéis/química , Magnetismo , Nanotecnologia , Temperatura , Vitrificação
17.
Int J Legal Med ; 135(6): 2581-2594, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34401961

RESUMO

Bone taphonomy is a widely investigated topic; however, few data are available concerning marine bone taphonomy, especially on remains recovered from great depths and with short post-mortem intervals. To date, few studies have evaluated the bony changes which occur in seawater compared to samples with different post-mortem histories, and none through a comparative analysis of different approaches. To this purpose, this pilot study aims to examine the influence of seawater on bone preservation compared to other depositional contexts by multiple perspectives. Forty-nine human bone samples (femurs or tibiae) recovered from different environments (sea water, fresh water, outdoor, burial in coffin) were compared by macroscopic, microscopic and bone densitometric approaches. In order to investigate organic and inorganic components, undecalcified and decalcified histology of thin sections was performed. The analyses revealed a well-preserved bone tissue both macroscopically (92%) and microscopically (97% and 95% for undecalcified and decalcified sections). No significant differences were detected from radiological densitometric investigations (BMD = 1.6 g/cm2 ± 0.1), except between old and young individuals (p value < 0.001). Differences were observed for body decomposition and few scavenged samples (3/15). However, even if slight variations were observed, no relation was recorded with the depositional contexts. We found a similar bone preservation in the four environments at the time of recovery, both macroscopically and microscopically, but also with radiological densitometric investigations. Our observations enriched the literature on bone taphonomy, providing data on bone tissue preservation in the early post-mortem period from a multidisciplinary perspective, paving the way for further studies on the topic.


Assuntos
Densidade Óssea , Osso e Ossos/fisiologia , Água do Mar , Preservação de Tecido , Adolescente , Adulto , Restos Mortais/fisiologia , Sepultamento , Feminino , Água Doce , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Mudanças Depois da Morte , Solo , Adulto Jovem
18.
Cryobiology ; 103: 123-128, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34454959

RESUMO

We evaluated the effect of open and closed systems used for ovarian tissue vitrification on the microbiological load and preservation of preantral follicles (PAFs) in the red-rumped agoutis. The ovaries from eight females were recovered and fragmented, with four cortexes fragments immediately fixed and evaluated (fresh group). The other fragments were processed for the solid-surface vitrification method (SSV) or an ovarian tissue cryosystem (OTC) using fetal calf serum, ethylene glycol, and sucrose as cryoprotectants, stored for two weeks, and rewarmed. Subsequently, fragments were subjected to a 24-h in vitro culture and assessed for microbiological load, PAF morphology, and DNA integrity. There was no fungal contamination; however, the vitrified samples from two individuals showed bacterial contamination of 79 200 colony forming units per milliliter (CFU)/mL for SSV and 3120 CFU/mL for OTC. From those samples, a total of eight different types of bacterial colonies were isolated and identified as coagulase-negative Staphylococci and Gram-positive bacilli. Regarding PAF morphology, both systems provided adequate preservation, with values higher than 70% normal follicles observed before and after culture. The TUNEL assay revealed that both SSV (52.39%) and OTC (41.67%) could preserve DNA integrity after vitrification and after 24 h of culture. In summary, both open and closed systems were equally efficient in preserving agouti ovarian tissues, especially concerning the preantral follicle morphology and DNA integrity; however, the OTC seems to provide a less adequate environment for bacterial proliferation.


Assuntos
Dasyproctidae , Vitrificação , Animais , Criopreservação/métodos , Crioprotetores/farmacologia , Feminino , Humanos , Folículo Ovariano , Preservação de Tecido
19.
PLoS One ; 16(8): e0255363, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34347814

RESUMO

The standard histological processing procedure, which produces excellent staining of sections for most tissues, fails to yield satisfactory results in adult mouse orbits or eyeballs. Here, we show that a protocol using tissue block staining and domestic adhesive tapes resulted in qualified integral serial cryo-sections of whole orbits or eyeballs, and the fine structures were well preserved. The histological processing protocol comprises paraformaldehyde fixation, ethylenediaminetetraacetic acid decalcification, tissue block staining with hematoxylin and eosin, embedding, adhesive tape aided sectioning, and water-soluble mounting. This protocol was proved to be the best in comparison with seven other related existing histological traditional or non-traditional processing methods, according to the staining slice quality. We observed a hundred percent success rate in sectioning, collection, and mounting with this method. The reproducibility tested on qualified section success rates and slice quality scores confirmed that the technique is reliable. The feasibility of the method to detect target molecules in orbits was verified by successful trial tests on block immunostaining and adhesive tape-aided sectioning. Application of this protocol in joints, brains, and so on,-the challenging integral sectioning tissues, also generated high-quality histological staining sections.


Assuntos
Olho/anatomia & histologia , Órbita/anatomia & histologia , Preservação de Tecido/instrumentação , Animais , Criopreservação , Estudos de Viabilidade , Feminino , Camundongos , Microtomia , Coloração e Rotulagem , Fita Cirúrgica , Inclusão do Tecido , Fixação de Tecidos , Preservação de Tecido/métodos
20.
Exp Eye Res ; 211: 108720, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34389315

RESUMO

The transplantation of expansions of limbal epithelial stem cells (LESC) remains one of the most efficient therapies for the treatment of limbal stem cell deficiency (LSCD) to date. However, the available donor corneas are scarce, and the corneas conserved for long time, under hypothermic conditions (after 7 days) or in culture (more than 28 days), are usually discarded due to poor viability of the endothelial cells. To establish an objective criterion for the utilisation or discarding of corneas as a source of LESC, we characterized, by immunohistochemistry analysis, donor corneas conserved in different conditions and for different periods of time. We also studied the potency of LESCs isolated from these corneas and maintained in culture up to 3 cell passages. We hoped that the study of markers of LESCs present in both the corneoscleral histological sections and the cell cultures would show the adequacy of the methods used for cell isolation and how fit the LESC enrichment of the obtained cell populations to be expanded was. Thus, the expressions of markers of the cells residing in the human limbal and corneal epithelium (cytokeratin CK15 and CK12, vimentin, Collagen VII, p63α, ABCG2, Ki67, Integrin ß4, ZO1, and melan A) were analysed in sections of corneoscleral tissues conserved in hypothermic conditions for 2-9 days with post-mortem time (pmt) < 8 h or for 1 day with pmt > 16 h, and in sclerocorneal rims maintained in an organ culture medium for 29 days. Cell populations isolated from donor corneoscleral tissues were also assessed based on these markers to verify the adequacy of isolation methods and the potential of expanding LESCs from these tissues. Positivity for several putative stem cell markers such as CK15 and p63α was detected in all corneoscleral tissues, although a decrease was recorded in the ones conserved for longer times. The barrier function and the ability to adhere to the extracellular matrix were maintained in all the analysed tissues. In limbal epithelial cell cultures, a simultaneous decrease in the melan A melanocyte marker and the putative stem cell markers was detected, suggesting a close relationship between the melanocytes and the limbal stem cells of the niche. Holoclones stained with putative stem cell markers were obtained from long-term, hypothermic, stored sclerocorneal rims. The results showed that the remaining sclerocorneal rims after corneal transplantation, which were conserved under hypothermic conditions for up to 7 days and would have been discarded at a first glance, still maintained their potential as a source of LESC cultures.


Assuntos
Córnea/citologia , Epitélio Corneano/citologia , Limbo da Córnea/citologia , Técnicas de Cultura de Órgãos/métodos , Células-Tronco/citologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Separação Celular , Células Cultivadas , Colágeno/metabolismo , Córnea/metabolismo , Epitélio Corneano/metabolismo , Humanos , Queratinas/metabolismo , Limbo da Córnea/metabolismo , Pessoa de Meia-Idade , Células-Tronco/metabolismo , Fatores de Tempo , Doadores de Tecidos , Preservação de Tecido/métodos , Vimentina/metabolismo
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