Abstracts of the Cell Therapy Transplant Canada 2023 Annual Conference.

On behalf of Cell Therapy Transplant Canada (CTTC), we are pleased to present the Abstracts of the CTTC 2023 Annual Conference. The conference was held in-person, 31 May-2 June 2023, in Halifax, Nova Scotia at the Westin Nova Scotian hotel. Poster authors presented their work during a lively and engaging welcome reception on Thursday, 1 June, and oral abstract authors were featured during the oral abstract session in the afternoon of Friday, 2 June 2023. Twenty-three (23) abstracts were selected for presentation as posters and four (4) as oral presentations. Abstracts were submitted within four categories: (1) Basic/Translational Sciences, (2) Clinical Trials/Observations, (3) Laboratory/Quality, and (4) Pharmacy/Nursing/Other Transplant Support. The top four (4) oral abstracts and top four (4) poster abstracts were selected to receive an award. All of these were marked as "Award Recipient" within the relevant category. We congratulate all the presenters on their research and contributions to the field.

Abstracts of the Cell Therapy Transplant Canada 2022 Annual Conference.

On behalf of Cell Therapy Transplant Canada (CTTC), we are pleased to present the Abstracts of the CTTC 2022 Annual Conference. The conference was held in-person 15-18 June 2022, in Niagara Falls, Ontario. Poster authors presented their work during a lively and engaging welcome reception on Thursday, 16 June, and oral abstract authors were featured during the oral abstract session in the afternoon on Friday, 17 June 2022. Thirty-three (33) abstracts were selected for presentation as posters and six (6) as oral presentations. The top abstracts in each of four (4) categories, (1) Basic/Translational sciences, (2) Clinical Trials/Observations, (3) Laboratory/Quality, and (4) Pharmacy/Nursing/Other Transplant Support, received awards for both the oral and poster presentations. All of these were marked as "Award Recipient" with the relevant category. We congratulate all the presenters on their research and contribution to the field.

Characterization of ABH-subtype donor-specific antibodies in ABO-A-incompatible kidney transplantation.

ABO-incompatible (ABOi) transplantation requires preemptive antibody reduction; however, the relationship between antibody-mediated rejection (AMR) and ABO-antibodies, quantified by hemagglutination (HA), is inconsistent, possibly reflecting variable graft resistance to AMR or HA assay limitations. Using an ABH-glycan microarray, we quantified ABO-A antigen-subtype (A-subtype)-specific IgM and IgG in 53 ABO-O recipients of ABO-A kidneys, before and after antibody removal (therapeutic plasma exchange [TPE] or ABO-A-trisaccharide immunoadsorption [IA]) and 1-year posttransplant. IgM binding to all A-subtypes correlated highly (R2  ≥ .90) and A-subtype antibody specificities was reduced equally by IA versus TPE. IgG binding to the A-subtypes (II-IV) expressed in kidney correlated poorly (.27 ≤ R2  ≤ .69). Reduction of IgG specific to A-subtype-II was equivalent for IA and TPE, whereas IgG specific to A-subtypes-III/IV was not as greatly reduced by IA (p < .005). One-year posttransplant, IgG specific to A-II remained the most reduced antibody. Immunostaining revealed only A-II on vascular endothelium but A-subtypes II-III/IV on tubular epithelium. These results show that ABO-A-trisaccharide is sufficient for IgM binding to all A-subtypes; this is true for IgG binding to A-II, but not subtypes-III/IV, which exhibits varying degrees of specificity. We identify A-II as the major, but importantly not the sole, antigen relevant to treatment and immune modulation in adult ABO-A-incompatible kidney transplantation.

Mass Spectrometric Lipid Profiles of Picosecond Infrared Laser-Generated Tissue Aerosols Discriminate Different Brain Tissues.

BACKGROUND AND OBJECTIVES: A picosecond infrared laser (PIRL) has recently been demonstrated to cut biological tissue without scar formation based on the minimal destructive action on the surrounding cells. During cutting with PIRL, the irradiated tissue is ablated by a cold vaporization process termed desorption by impulsive vibrational excitation. In the resulting aerosol, all molecules are dissolved in small droplets and even labile biomolecules like proteins remain intact after ablation. It is hypothesized that these properties enable the PIRL in combination with mass spectrometry as an intelligent laser scalpel for guided surgery. In this study, it was tested if PIRL-generated tissue aerosols are applicable for direct analysis with mass spectrometry, and if the acquired mass spectra can be used to discriminate different brain areas. MATERIALS AND METHODS: Brain tissues were irradiated with PIRL. The aerosols were collected and directly infused into a mass spectrometer via electrospray ionization without any sample preparation or lipid extraction. RESULTS: The laser produced clear cuts with no marks of burning. Lipids from five different classes were identified in the mass spectra of all samples. By principal component analysis the different brain areas were clearly distinguishable from each other. CONCLUSIONS: The results demonstrate the potential for real-time analysis of lipids with a PIRL-based laser scalpel, coupled to a mass spectrometer, for the discrimination of tissues during surgeries. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Sampling of Tissues with Laser Ablation for Proteomics: Comparison of Picosecond Infrared Laser and Microsecond Infrared Laser.

It was recently shown that sampling of tissues with a picosecond infrared laser (PIRL) for analysis with bottom-up proteomics is advantageous compared to mechanical homogenization. Because the cold ablation of tissues with PIRL irradiation is soft, proteins remain intact and even enzymatic activities are detectable in PIRL homogenates. In contrast, it was observed that irradiation of tissues with a microsecond infrared laser (MIRL) heats the tissue, thereby causing significant damage. In this study, we investigated the question if sampling of tissues with a MIRL for analysis of their proteomes via bottom-up proteomics is possible and how the results are different from sampling of tissues with a PIRL. Comparison of the proteomes of the MIRL and PIRL tissue homogenates showed that the yield of proteins identified by bottom-up proteomics was larger in PIRL homogenates of liver tissue, whereas the yield was higher in MIRL homogenates of muscle tissue, which has a significantly higher content of connective tissue than liver tissue. In the PIRL homogenate of renal tissue, enzymatic activities were detectable, whereas in the corresponding MIRL homogenate, enzymatic activities were absent. In conclusion, MIRL and PIRL pulses are suited for sampling tissues for bottom-up proteomics. If it is important for bottom-up proteomic investigations to inactivate enzymatic activities already in the tissue before its ablation, MIRL tissue sampling is an option, because the proteins in the tissues are denatured and inactivated by the heating of the tissue during irradiation with MIRL irradiation prior to the ablation of the tissue. This heating effect is absent during irradiation of tissue with a PIRL; therefore, sampling of tissues with a PIRL is a choice for purifying enzymes, because their activities are maintained.

Towards OCT-Navigated Tissue Ablation with a Picosecond Infrared Laser (PIRL) and Mass-Spectrometric Analysis.

Medical lasers are commonly used in interventions to ablate tumor tissue. Recently, the picosecond infrared laser has been introduced, which greatly decreases damaging of surrounding healthy tissue. Further, its ablation plume contains intact biomolecules which can be collected and analyzed by mass spectrometry. This allows for a specific chracterization of the tissue. For a precise treatment, however, a suitable guidance is needed. Further, spatial information is required if the tissue is to be characterized at different parts in the ablated area. Therefore, we propose a system which employs optical coherence tomography as the guiding imaging modality. We describe a prototypical system which provides automatic ablation of areas defined in the image data. For this purpose, we use a calibration with a robot which drives the laser fiber and collects the arising plume. We demonstrate our system on porcine tissue samples.

Picosecond Infrared Laser (PIRL) Application in Stapes Surgery-First Experience in Human Temporal Bones.

OBJECTIVE: Using a contact-free laser technique for stapedotomy reduces the risk of mechanical damage of the stapes footplate. However, the risk of inner ear dysfunction due to thermal, acoustic, or direct damage has still not been solved. The objective of this study was to describe the first experiences in footplate perforation in cadaver tissue performed by the novel Picosecond-Infrared-Laser (PIRL), allowing a tissue preserving ablation. PATIENTS AND INTERVENTION: Three human cadaver stapes were perforated using a fiber-coupled PIRL. The results were compared with footplate perforations performed with clinically applied Er:YAG laser. Therefore, two different laser energies for the Er:YAG laser (30 and 60 mJ) were used for footplate perforation of three human cadaver stapes each. MAIN OUTCOME MEASURE: Comparisons were made using histology and environmental scanning electron microscopy (ESEM) analysis. RESULTS: The perforations performed by the PIRL (total energy: 640-1070 mJ) revealed a precise cutting edge with an intact trabecular bone structure and no considerable signs of coagulation. Using the Er:YAG-Laser with a pulse energy of 30 mJ (total energy: 450-600 mJ), a perforation only in the center of the ablation zone was possible, whereas with a pulse energy of 60 mJ (total energy: of 195-260 mJ) the whole ablation zone was perforated. For both energies, the cutting edge appeared irregular with trabecular structure of the bone only be conjecturable and signs of superficial carbonization. CONCLUSION: The microscopic results following stapes footplate perforation suggest a superiority of the PIRL in comparison to the Er:YAG laser regarding the precision and tissue preserving ablation.

Melanoma and tattoos: a case report and review of the literature.

BACKGROUND: Malignant melanoma cases arising in tattoos have been increasingly described, however, there is no clear relationship between this practice and the development of cutaneous malignancies. OBJECTIVES: We report a new case of melanoma in a dark-blue tattoo and we review all cases of melanoma reported in the medical literature from 1938 to date. MATERIALS & METHODS: Pubmed and Google Scholar were searched using the terms "melanoma tattoo", "tattoo skin tumour" and "ink melanoma". RESULTS: In most cases, the melanoma occurred on dark blue (10/30), black (8/30), or blue ink (3/30). The Breslow thickness at diagnosis was ≤1 mm in 13/30, 1-2 mm in 3/30, 2-4 mm in 2/30, >4 mm in 5/30, and Clark II in 2/30 (not available in 5/30). CONCLUSIONS: Both the incidence of melanoma and the number of tattoos have been increasing in recent years, but a possible carcinogenic effect of tattoos remains unproven. The spread of this decorative custom will make observation of melanoma in tattoos more frequent in dermatological practice, therefore these cases should be reported in national skin cancer registries.

Evaluation of the design and reliability of three elastomeric and one mechanical infusers.

BACKGROUND: Disposable elastomeric and mechanical (spring mechanism) infusers with pre-fixed flow rates are principally used for long-term antibiotic therapy, chemotherapy, antiviral therapy, and chronic pain management. METHODS: Three elastomeric pumps and one mechanical infuser pump are evaluated. The design and function are assessed using specific questionnaires elaborated for the pharmaceutical staff, nurses and patients, respectively. Several tests are performed to determine the flow accuracy and the influence of different parameters such as the temperature, the viscosity, the height, and the restrictor variability. RESULTS: The functional tests show that the perfusion duration is shorter than that specified by the manufacturers, the restrictors are not homogeneous within a batch. However, the temperature of the regulator, the viscosity of the solution, and the height of the reservoir influence the flow rate. CONCLUSIONS: The ideal infuser should be small, light, unnoticeable, easy to fill, well identified and have a flow rate barely affected by external factors. None of the infusers has fulfilled all criteria, therefore the choice of infusers depends upon the nature of the treatment. The tested elastomeric infusers are adequate for 5-fluorouracil, but not for a treatment requiring a stable administration rate.

High prevalence of aeroallergen sensitization among infants of atopic parents.

OBJECTIVE: To present methodology to identify atopic parents and determine the prevalence of sensitization to 15 aeroallergens in their infant offspring. STUDY DESIGN: A birth cohort of infants was identified from birth records; an infant was enrolled if 1 of the parents reported allergy respiratory symptoms and had a positive skin prick test (SPT) to a common aeroallergen. At age 1 year, these infants were tested to the same aeroallergens. RESULTS: Of the 680 enrolled infants, 28.4% were SPT+ to 1 or more aeroallergens and/or food, and 18.0% were positive to 1 or more aeroallergens. By category of allergens, 9.7% were sensitized to pollens, 7.5% to molds, 4.3% to house dust mite and/or cockroach, and 3.4% to dog and/or cat. Of the infants who were positive to an aeroallergen, 65.7% remained positive at age 2 years. CONCLUSIONS: Infants born to atopic parents with percutaneous sensitization to aeroallergens are at increased risk for aeroallergen sensitization during infancy, which persists to age 2 years. These findings suggest that current clinical practices, which generally avoid skin testing before age 2 years, be reassessed in this population of high-risk children.

Phylogenetic analysis reveals a novel protein family closely related to adenosine deaminase.

Adenosine deaminase (ADA) is a well-characterized enzyme involved in the depletion of adenosine levels. A group of proteins with similarity to ADA, the adenosine deaminase-related growth factors (ADGF; known as CECR1 in vertebrates), has been described recently in various organisms. We have determined the phylogenetic relationships of various gene products with significant amino acid similarity to ADA using parsimony and Bayesian methods, and discovered a novel paralogue, termed ADA-like (ADAL). The ADGF proteins share a novel amino acid motif, "MPKG," within which the proline and lysine residues are also conserved in the ADAL and ADA subfamilies. The significance of this new domain is unknown, but it is located just upstream of two ADA catalytic residues, of which all eight are conserved among the ADGF and ADAL proteins. This conservation suggests that ADGF and ADAL may share the same catalytic function as ADA, which has been proven for some ADGF members. These analyses also revealed that some genes previously thought to be classic ADAs are instead ADAL or ADGFs. We here define the ADGF, ADAL, ADA, adenine deaminase (ADE), and AMP deaminase (AMPD) groups as subfamilies of the adenyl-deaminase family. The availability of genomic data for the members of this family allowed us to reconstruct the intron evolution within the phylogeny and strengthen the introns-late hypothesis of the synthetic introns theory. This study shows that ADA activity is clearly more complex than once thought, perhaps involving a delicately balanced pattern of temporal and spatial expression of a number of paralogous proteins.