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Marialuisa Lavitrano

Publications and source records attributed to Marialuisa Lavitrano.

14 recordsLinked to original sources

Toward a unified approach: Considerations for bioinformatic and sequencing activities & data in wastewater surveillance of biologic public health threats.

Genomic technologies such as PCR and next-generation sequencing (NGS) have greatly advanced public health surveillance, especially during COVID-19, by enabling detailed tracking of pathogen spread, origins, and variants. While PCR is vital for targeted detection, falling NGS costs have made large-scale, high-throughput sequencing more feasible, supporting broader pathogen monitoring-including the detection of vaccine escape variants and new strains. Applying NGS to wastewater offers valuable population-level insights but faces challenges such as variable sample complexity, the need for skilled staff, suitable platforms, and robust IT infrastructure. Although there are currently a lot of efforts towards defining guidelines for sampling, analysis, and integrating wastewater data into public health policy, such as the recently published International Cookbook for Wastewater Practitioners, they often lack universal applicability, emphasizing the analytical approaches in favour of the NGS-based approaches. However, standardising protocols for sampling, sequencing, and analysis is crucial to ensure reliable, comparable data across surveillance systems worldwide. Pilot studies and continuous refinement are recommended to overcome implementation hurdles and fully realise the benefits of NGS in wastewater surveillance. This work attempts to outline these challenges and opportunities across the entire wastewater surveillance workflow, from data generation to reporting, and provide some concrete suggestions and considerations across the spectrum of activities. We further highlight that the infrastructure, funding and government-policy context in which surveillance operates acts as an enabling condition for these activities, and that technical standardisation alone is unlikely to deliver durable, comparable surveillance in its absence.

considerations↗

Genetically modified pigs produced with a nonviral episomal vector.

Genetic modification of cells and animals is an invaluable tool for biotechnology and biomedicine. Currently, integrating vectors are used for this purpose. These vectors, however, may lead to insertional mutagenesis and variable transgene expression and can undergo silencing. Scaffold/matrix attachment region-based vectors are nonviral expression systems that replicate autonomously in mammalian cells, thereby making possible safe and reliable genetic modification of higher eukaryotic cells and organisms. In this study, genetically modified pig fetuses were produced with the scaffold/matrix attachment region-based vector pEPI, delivered to embryos by the sperm-mediated gene transfer method. The pEPI vector was detected in 12 of 18 fetuses in the different tissues analyzed and was shown to be retained as an episome. The reporter gene encoded by the pEPI vector was expressed in 9 of 12 genetically modified fetuses. In positive animals, all tissues analyzed expressed the reporter gene; moreover in these tissues, the positive cells were on the average 79%. The high percentage of EGFP-expressing cells and the absence of mosaicism have important implications for biotechnological and biomedical applications. These results are an important step forward in animal transgenesis and can provide the basis for the future development of germ-line gene therapy.

Animals↗

Reduction of hyperacute rejection and protection of metabolism and function in hearts of human decay accelerating factor (hDAF)-expressing pigs.

OBJECTIVE: The use of pig hearts can solve the problem of shortage of donor hearts for transplantation. However, targeting rejection by single genetic modification was proven to be ineffective, highlighting the requirement for complex genetic modifications and more effective methods for transgenic animal production. We evaluated here whether hearts of hDAF transgenic pigs generated using our technique sperm-mediated gene transfer (SMGT) will be protected from structural damage, metabolic changes, and mechanical dysfunction during perfusion with human blood. METHODS: Hearts from control (C, n = 6) or transgenic (T, n = 5) pigs were perfused ex vivo for 4 h with fresh human blood using the ex vivo working mode system allowing monitoring of the function, metabolism, and structure. RESULTS: Cardiac output (mean+/-SEM) was maintained in T constant throughout the experiment, at 3.58+/-0.36 and 3.83+/-0.14 l/min after 30 min and 4 h, respectively, while cardiac output decreased to 1.95+/-0.35 l/min in C after 30 min of perfusion (p < 0.01 vs. T). The maximum increase in coronary perfusion pressure was reduced in T to 154+/-16% as compared to C (237+/-10%, p < 0.001). Myocardial ATP after 4 h was 21.1+/-1.1 nmol/mg dry wt (similar to initial) in T, while it decreased in C to 17.2+/-1.4 (p < 0.05). Deposition of complement factors C3 and C5b9 was present in C but not in T after perfusion. CONCLUSION: We have shown that hearts from hDAF transgenic pigs produced by SMGT are protected during perfusion with human blood and are metabolically stable and maintain mechanical function above the threshold level for life support.

Acute Disease↗

Sperm-mediated gene transfer.

Since 1989, a new method for the production of transgenic animals has been available, namely sperm-mediated gene transfer (SMGT), based on the intrinsic ability of sperm cells to bind and internalise exogenous DNA molecules and to transfer them into the oocyte at fertilisation. We first described the SMGT procedure in a small animal model, with high efficiency reported in the mouse. In addition, we successfully adapted and optimised the technique for use in large animals; it was, in fact, highly efficient in the generation of human decay accelerating factor transgenic pig lines, as well as multigene transgenic pigs in which three different reporter genes, namely enhanced green fluorescent protein, enhanced blue fluorescent protein and red fluorescent protein, were introduced. The major benefits of the SMGT technique were found to be its high efficiency, low cost and ease of use compared with other methods. Furthermore, SMGT does not require embryo handling or expensive equipment. Sperm-mediated gene transfer could also be used to generate multigene transgenic pigs that would be of benefit as large animal models for medical research, for agricultural and pharmaceutical applications and, in particular, for xenotransplantation, which requires extensive genetic manipulation of donor pigs to make them suitable for grafting to humans.

Animals↗

Rationale and design of a multidisciplinary national real-world registry on carotid stenting: the Italian Registry for Carotid Stenting (RISC).

The Registro Italiano per lo Stenting Carotideo (RISC, Italian Registry for Carotid Stenting) has been organized by Italian specialists from different disciplines directly involved in the prevention of stroke due to carotid plaques through stenting of carotid lesions. The Registry has been endorsed by the national societies of 4 different specialties: vascular surgery, interventional cardiology, radiology, and neuroradiology. Each society contributed in the planning stage. The basis for the registry is to collect data on carotid stenting procedures performed by different specialists with different techniques in a "real-world" setting without the limitations of a randomized clinical trial. The Registry was funded to enroll at least 1200 patients over a minimum period of 36 months. The results will be analyzed using the intention-to-treat principle and are anticipated in late 2006. Primary endpoints of the registry are the 30-day combined death and stroke rate and the occurrence of restenosis and ipsilateral neurological deficit at 12 and 24 months. Considerable attention has been paid to the registry's quality control program to ensure scientific validation. An online database facilitates the collection of data with speed and accuracy.

Carotid Stenosis↗

Loss of ecto-5'nucleotidase from porcine endothelial cells after exposure to human blood: Implications for xenotransplantation.

The endothelial cell surface expression of ecto-5'-nucleotidase (E5'N, CD73) is thought to be essential for the extracellular formation of cytoprotective, anti-thrombotic and immunosuppressive adenosine. Decreased E5'N activity may play a role in xenograft acute vascular rejection, preventing accommodation and tolerance mechanisms. We investigated the extent of changes in E5'N activity and other enzymes of purine metabolism in porcine hearts or endothelial cells when exposed to human blood or plasma and studied the role of humoral immunity in this context. Pig hearts, wild type (WT, n = 6) and transgenic (T, n = 5) for human decay accelerating factor (hDAF), were perfused ex vivo with fresh human blood for 4 h. Pig aortic endothelial cells (PAEC) were exposed for 3 h to autologous porcine plasma (PP), normal (NHP) or heat inactivated human plasma (HHP), with and without C1-inhibitor. Enzyme activities were measured in heart or endothelial cell homogenates with an HPLC based procedure. The baseline activity of E5'N in WT and T porcine hearts were 6.60 +/- 0.33 nmol/min/mg protein and 8.54 +/- 2.10 nmol/min/mg protein respectively (P < 0.01). Ex vivo perfusion of pig hearts with fresh human blood for 4 h resulted in a decrease in E5'N activity to 4.01 +/- 0.32 and 4.52 +/- 0.52 nmol/min/mg protein (P < 0.001) in WT and T hearts respectively, despite attenuation of hyperacute rejection in transgenic pigs. The initial PAEC activity of E5'N was 9.10 +/- 1.40 nmol/min/mg protein. Activity decreased to 6.76 +/- 0.57 and 4.58 +/- 0.47 nmol/min/mg protein (P < 0.01) after 3 h exposure of HHP and NHP respectively (P < 0.05), whereas it remained unchanged at 9.62 +/- 0.88 nmol/min/mg protein when incubated with PP controls. C1-inhibitor partially preserved E5'N activity, similar to the effect of HHP. Adenosine deaminase, adenosine kinase and AMP deaminase (other enzymes of purine metabolism) showed a downward trend in activity, but none were statistically significant. We demonstrate a specific decrease in E5'N activity in pig hearts following exposure to human blood which impairs adenosine production resulting in a loss of a cytoprotective phenotype, contributing to xenograft rejection. This effect is triggered by human humoral immune responses, and complement contributes but does not fully mediate E5'N depletion.

5'-Nucleotidase↗

Multi-transgenic pigs expressing three fluorescent proteins produced with high efficiency by sperm mediated gene transfer.

Multi-gene transgenic pigs would be of benefit for large animal models in medical, agricultural, and pharmaceutical applications; in particular for xenotransplantation, where extensive genetic manipulation of donor pigs is required to make them suitable for organ grafting to humans. We used the sperm mediated gene transfer (SMGT) method to produce with high efficiency multi-gene transgenic pigs using three genes coding for fluorescent proteins: enhanced blue (EBFP), green (EGFP), and red (DsRed2). All three fluorescent proteins were expressed in 171 out of 195 normally developed morula/blastocysts examined at day 6 post insemination (88%). Genomic DNA of 18 piglets born from two litters was screened by PCR, showing that all piglets were transgenic with at least one gene, 7/18 piglets were triple transgenic, 7/18 double transgenic, and 4/18 single transgenic. Fluorescence in situ hybridization (FISH) analysis revealed multiple sites of integration of the transgenes. RNA and protein expression was found in muscle, heart, liver, hair, and peripheral blood mononuclear cells (PBMCs). These results show that SMGT is an effective method for introducing multiple genes into pigs as shown by the simultaneous expression of three fluorescent proteins.

Animals↗

Expression of human ecto-5'-nucleotidase in pig endothelium increases adenosine production and protects from NK cell-mediated lysis.

Ecto-5'-nucleotidase (E5'N) is an endothelial surface enzyme that controls conversion of extracellular nucleotides into immunosuppressive adenosine. We evaluated whether expression of human E5'N on pig endothelial cells (EC) attenuates human NK cell-mediated cytotoxicity. A pig EC line was stably transfected with human E5'N and human NK cell adhesion and cytotoxicity toward pig EC cultures was measured by flow cytometry and intracellular enzyme release. E5'N activity in pig EC lysates increased from 0.68 +/- 0.07 to 1013 +/- 293 nmol/min/mg protein, whilst the rate of AMP to adenosine metabolism by intact cells increased from 0.37 +/- 0.05 to >300 nmol/min/mg protein in non-transfected and transfected cells, respectively. The rate of adenosine production in transfected cells increased also with ATP as the extracellular substrate. Cytotoxicity of human NK cells was reduced from 10.7 +/- 0.4% and 11.1 +/- 1.1% with non-transfected pig EC to 5.2 +/- 0.2% and 5.0 +/- 0.2% in transfected cells with 50 microM and 250 microM AMP, respectively. Reduction of cytotoxicity in E5'N-transfected EC was abolished by the E5'N inhibitor and was mimicked in non-transfected EC by the addition of adenosine, demonstrating the key role of adenosine produced by E5'N in inhibiting NK cell cytotoxicity. We suggest that overexpression of E5'N in EC of transgenic pigs is a possible strategy to ameliorate rejection after xenotransplantation.

5'-Nucleotidase↗

Carbon monoxide improves cardiac energetics and safeguards the heart during reperfusion after cardiopulmonary bypass in pigs.

Ischemia-reperfusion injury, a clinical problem during cardiac surgery, involves worsened adenosine trisphosphate (ATP) generation and damage to the heart. We studied carbon monoxide (CO) pretreatment, proven valuable in rodents but not previously tested in large animals, for its effects on pig hearts subjected to cardiopulmonary bypass with cardioplegic arrest. Hearts of CO-treated pigs showed significantly higher ATP and phosphocreatine levels, less interstitial edema, and apoptosis of cardiomyocytes and required fewer defibrillations after bypass. We conclude that treatment with CO improves the energy status, prevents edema formation and apoptosis, and facilitates recovery in a clinically relevant model of cardiopulmonary bypass surgery.

Adenosine Diphosphate↗

Islet beta-cell apoptosis triggered in vivo by interleukin-1beta is not related to the inducible nitric oxide synthase pathway: evidence for mitochondrial function impairment and lipoperoxidation.

IL-1beta is recognized as an effector cytokine contributing to islet beta-cell destruction during diabetes. We have previously shown in vitro that IL-1beta induces nitric oxide (NO) and beta-cell damage. Here, we show that IL-1beta administration in vivo to Wistar rats transiently increases manganese superoxide dismutase activity, whereas inducible NO synthase is not detected, and the levels of nitrate+nitrate do not change. Moreover, a significant decrease of mitochondrial aconitase, leading to a rise of hydroperoxides, and islet beta-cell apoptosis, involving caspase-3 and -8, is observed. Analysis of adhesion molecules in beta-cells showed that intercellular adhesion molecule-1 is highly expressed 48 h after IL-1beta administration and that this is concomitant to the fall of manganese superoxide dismutase activity. Thus, IL-1beta exerts a proapoptotic effect in vivo through mitochondrial enzyme alteration, which is not related to the inducible NO synthase pathway, and dysregulates the immune system through the up-regulation of adhesion molecules.

Aconitate Hydratase↗

Sperm mediated gene transfer in pig: Selection of donor boars and optimization of DNA uptake.

Transgenic animals are produced primarily by microinjecting exogenous DNA into the male pronuclei of a zygote. Microinjection is successful in mice but not efficient in farm animals, limiting its general utility. We have pursued an alternative technology for producing transgenic animals: Sperm Mediated Gene Transfer (SMGT). Based on our finding that sperm cells bind and internalize exogenous DNA, we used sperm as a vector for transmitting, not only their own DNA, but also, the exogenously-introduced gene of interest to the zygote. SMGT is highly efficient (up to greater than 80%) and relatively inexpensive; it can be used in species refractory to microinjection, whenever reproduction is mediated by gametes. In this report, we describe the procedure for selection of sperm donors and optimization of DNA uptake that are the key steps for the successful outcome of SMGT. We found that the nominal parameters that boar sperm should possess to serve as a good vector for exogenous DNA are the quality of semen based on standard parameters used in conventional animal breeding programs (volume, concentration, presence of abnormal sperm cells, motility at time of collection, and high progressive motility after 2 hr) and the ability of the sperm cells to take up and internalize exogenous DNA. The results described provide significant advances in SMGT technology applied to pigs, so that transgenic pigs can be efficiently obtained. Mol.

Animals↗

Efficient production by sperm-mediated gene transfer of human decay accelerating factor (hDAF) transgenic pigs for xenotransplantation.

A large number of hDAF transgenic pigs to be used for xenotransplantation research were generated by using sperm-mediated gene transfer (SMGT). The efficiency of transgenesis obtained with SMGT was much greater than with any other method. In the experiments reported, up to 80% of pigs had the transgene integrated into the genome. Most of the pigs carrying the hDAF gene transcribed it in a stable manner (64%). The great majority of pigs that transcribed the gene expressed the protein (83%). The hDAF gene was transmitted to progeny. Expression was stable and found in caveolae as it is in human cells. The expressed gene was functional based on in vitro experiments performed on peripheral blood mononuclear cells. These results show that our SMGT approach to transgenesis provides an efficient procedure for studies involving large animal models.

Animals↗

Construction of a swine artificial chromosome: a novel vector for transgenesis in the pig.

A de novo SAC was constructed by making use of YAC technology and a humanized yeast strain. The construct (about 310 kb) contained pig centromeric DNA and the Neo gene. The construct was introduced into a pig cell line by yeast-mammalian cell fusion and G418 resistant clones were obtained. One clone was characterized by FISH and shown to contain an episomally located microchromosome containing YAC, Neo and pig centromere sequences. FISH analysis over time showed that the SAC was mitotically stable for at least 34 generations in the absence of selection. The size of the SAC was determined by confocal microscopy of the SAC and shown to be approximately 7 Mb, which is about 25-fold greater than the size of the original YAC. From its behavior in pulsed field gel electrophoresis, FISH analysis of stretched DNA fibers, and its appearance under scanning confocal microscopy, it was concluded that the SAC is a circularized and multimerized derivative of the original YAC. Possible applications as vectors for animal transgenesis are discussed.

Animals↗