Número de células CD34+ circulantes como predictor de recolección exitosa de progenitores hematopoyéticos por aféresis en trasplante autólogo / Number of circulating CD34+ cells as a predictor of successful collection of hematopoietic progenitors by apheresis in autologous transplantation

RESUMEN Introducción. El trasplante autólogo de células progenitoras hematopoyéticas es una terapia eficaz en neoplasias malignas hematológicas. El número de células que CD34+ en sangre periférica es el mejor predictor del rendimiento de recolección de células progenitoras hematopoyéticas. Objetivo. Determinar el número de células CD34+ en sangre periférica asociado al éxito de recolección de progenitores hematopoyéticos por aféresis en trasplante autólogo. Métodos. Se evaluó retrospectivamente los datos de 236 procedimientos de aféresis de células progenitoras hematopoyéticas para el trasplante autólogo en el Hospital Edgardo Rebagliati Martins (Lima, Perú) de julio del 2020 a julio del 2023. Se utilizó la curva ROC (características operativas del receptor) para determinar el número de células CD34+ en sangre periférica necesario para lograr una recolección por aféresis ≥ 2 x 106 células CD34+/kg. Resultados. El 61% fueron hombres, con mediana de edad de 58 años, el valor de corte fue de 18,38 células CD34+/μL (sensibilidad de 94,1% y especificidad de 96,9%). Conclusión. El número de células CD34+ sangre periférica para una recolección exitosa de células progenitoras hematopoyéticas para el trasplante autólogo fue de 18,38 células CD34+/μL.

ABSTRACT Introduction. Autologous hematopoietic progenitor cell transplantation is an effective therapy in hematological malignancies, the number of CD34+ cells in peripheral blood is the best predictor of hematopoietic progenitor cell harvesting performance. Objective. To determine the number of CD34+ cells in peripheral blood associated with the successful collection of hematopoietic progenitors by apheresis in autologous transplantation. Methods. The data of 236 hematopoietic progenitor cell apheresis procedures for autologous transplantation at the Edgardo Rebagliati Martins Hospital (Lima, Peru) were retrospectively evaluated from July 2020 to July 2023. The ROC (receiver operating characteristics) curve was used to determine the number of CD34+ cells in peripheral blood necessary to achieve an collection by apheresis ≥ 2 x 106 CD34+ cells/kg. Results. 61% were men, with a median age of 58 years, the cut-off value was 18.38 CD34+ cells/μL (sensitivity of 94.1% and specificity of 96.9%). Conclusion. The number of peripheral blood CD34+cells for successful collection of hematopoietic progenitor cells for autologous transplantation was 18.38 CD34+ cells/μL.

Administration of an AAV vector coding for a P2X7-blocking nanobody-based biologic ameliorates colitis in mice.

BACKGROUND: The pro-inflammatory ATP-gated P2X7 receptor is widely expressed by immune and non-immune cells. Nanobodies targeting P2X7, with potentiating or antagonistic effects, have been developed. Adeno-associated virus (AAV)-mediated gene transfer represents an efficient approach to achieve long-term in vivo expression of selected nanobody-based biologics. This approach (AAVnano) was used to validate the relevance of P2X7 as a target in dextran sodium sulfate (DSS)-induced colitis in mice. RESULTS: Mice received an intramuscular injection of AAV vectors coding for potentiating (14D5-dimHLE) or antagonistic (13A7-Fc) nanobody-based biologics targeting P2X7. Long-term modulation of P2X7 activity was evaluated ex vivo from blood samples. Colitis was induced with DSS in mice injected with AAV vectors coding for nanobody-based biologics. Severity of colitis, colon histopathology and expression of chemokines and cytokines were determined to evaluate the impact of P2X7 modulation. A single injection of an AAV vector coding for 13A7-Fc or 14D5-dimHLE efficiently modulated P2X7 function in vivo from day 15 up to day 120 post-injection in a dose-dependent manner. An AAV vector coding for 13A7-Fc significantly ameliorated DSS-induced colitis and significantly reduced immune cell infiltration and expression of chemokines and proinflammatory cytokines in colonic tissue. CONCLUSIONS: We have demonstrated the validity of AAVnano methodology to modulate P2X7 functions in vivo. Applying this methodological approach to a DSS-induced colitis model, we have shown that P2X7 blockade reduces inflammation and disease severity. Hence, this study confirms the importance of P2X7 as a pharmacological target and suggests the use of nanobody-based biologics as potential therapeutics in inflammatory bowel disease.

Cutaneous Infection Associated With Myroides odoratimimus Bacteremia in a Diabetic Patient.

In daily medical practice, there exist multidrug resistance bacteria that are not widely recognized. One example of that is the Myroides spp., a Gram-negative bacillus causing skin, urinary, and bloodstream infections, especially in immunocompromised patients. In recent years, multiple cases of difficult hospital management have been reported. Currently, there are no specific guidelines for the prevention and treatment of this infection. This case report presents a patient with type 2 diabetes mellitus with a severe skin infection caused by this microorganism. This is the first case report in Peru of a severe skin infection related to Myroides odoratimimus bacteremia.

Otitis externa maligna con diseminación hematógena de Pseudomonas aeruginosa resistente a carbapenémicos

Pseudomonas aeruginosa en una bacteria Gram negativa no fermentadora que produce diversos tipos de infecciones severas en inmunocompetentes e inmunodeprimidos. Una de estas infecciones es la otitis externa maligna, la cual se presenta principalmente en personas con diabetes mellitus y puede tener una evolución tórpida cursando con osteomielitis de base de cráneo y parálisis de nervios craneales. El tratamiento es individualizado y principalmente conservador con antibioticoterapia guiada por cultivo. La bacteria aislada en la mayoría de los casos reportados es sensible a los antibióticos anti-pseudomónicos. Reportamos un caso de presentación inusual de otitis externa maligna por Pseudomonas aeruginosa resistente a carbapenémicos con evidencia sugerente de compromiso bilateral y en el cual se aisló al mismo germen en urocultivo y hemocultivos, lo que indicaría una diseminación hematógena del microorganismo.

Pseudomonas aeruginosa is a non-fermenting Gram-negative bacterium that produces several types of severe infections in immunocompetent and immunosuppressed patients. One of these infections is malignant otitis externa, which occurs mainly in people with diabetes mellitus and can have a torpid evolution coursing with osteomyelitis of skull base and cranial nerve palsies. Treatment is individualized and mainly conservative with culture-guided antibiotic therapy, with isolated pseudomonas being sensitive to anti-pseudomonal antibiotics in the majority of reported cases. We report a case of unusual presentation of malignant otitis externa caused by Pseudomonas aeruginosa resistant to carbapenems with suggestive evidence of bilateral involvement and in which the same germ was isolated in urine and blood cultures, which would indicate hematogenous dissemination of the microorganism.

Origin, distribution, and function of three frequent coding polymorphisms in the gene for the human P2X7 ion channel.

P2X7, an ion channel gated by extracellular ATP, is widely expressed on the plasma membrane of immune cells and plays important roles in inflammation and apoptosis. Several single nucleotide polymorphisms have been identified in the human P2RX7 gene. In contrast to other members of the P2X family, non-synonymous polymorphisms in P2X7 are common. Three of these occur at overall frequencies of more than 25% and affect residues in the extracellular "head"-domain of P2X7 (155 Y/H), its "lower body" (270 R/H), and its "tail" in the second transmembrane domain (348 T/A). Comparison of the P2X7 orthologues of human and other great apes indicates that the ancestral allele is Y-R-T (at 155-270-348). Interestingly, each single amino acid variant displays lower ATP-sensitivity than the ancestral allele. The originally published reference sequence of human P2X7, often referred to as "wildtype," differs from the ancestral allele at all three positions, i.e. H-H-A. The 1,000 Genome Project determined the sequences of both alleles of 2,500 human individuals, including roughly 500 persons from each of the five major continental regions. This rich resource shows that the ancestral alleles Y155, R270, and T348 occur in all analyzed human populations, albeit at strikingly different frequencies in various subpopulations (e.g., 25%-59% for Y155, 59%-77% for R270, and 13%-47% for T348). BLAST analyses of ancient human genome sequences uncovered several homozygous carriers of variant P2X7 alleles, possibly reflecting a high degree of inbreeding, e.g., H-R-T for a 50.000 year old Neanderthal, H-R-A for a 24.000 year old Siberian, and Y-R-A for a 7,000 year old mesolithic European. In contrast, most present-day individuals co-express two copies of P2X7 that differ in one or more amino acids at positions 155, 270, and 348. Our results improve the understanding of how P2X7 structure affects its function and suggest the importance of considering P2X7 variants of participants when designing clinical trials targeting P2X7.

Blocking P2X7 by intracerebroventricular injection of P2X7-specific nanobodies reduces stroke lesions.

BACKGROUND: Previous studies have demonstrated that purinergic receptors could be therapeutic targets to modulate the inflammatory response in multiple models of brain diseases. However, tools for the selective and efficient targeting of these receptors are lacking. The development of new P2X7-specific nanobodies (nbs) has enabled us to effectively block the P2X7 channel. METHODS: Temporary middle cerebral artery occlusion (tMCAO) in wild-type (wt) and P2X7 transgenic (tg) mice was used to model ischemic stroke. Adenosine triphosphate (ATP) release was assessed in transgenic ATP sensor mice. Stroke size was measured after P2X7-specific nbs were injected intravenously (iv) and intracerebroventricularly (icv) directly before tMCAO surgery. In vitro cultured microglia were used to investigate calcium influx, pore formation via 4,6-diamidino-2-phenylindole (DAPI) uptake, caspase 1 activation and interleukin (IL)-1ß release after incubation with the P2X7-specific nbs. RESULTS: Transgenic ATP sensor mice showed an increase in ATP release in the ischemic hemisphere compared to the contralateral hemisphere or the sham-treated mice up to 24 h after stroke. P2X7-overexpressing mice had a significantly greater stroke size 24 h after tMCAO surgery. In vitro experiments with primary microglial cells demonstrated that P2X7-specific nbs could inhibit ATP-triggered calcium influx and the formation of membrane pores, as measured by Fluo4 fluorescence or DAPI uptake. In microglia, we found lower caspase 1 activity and subsequently lower IL-1ß release after P2X7-specific nb treatment. The intravenous injection of P2X7-specific nbs compared to isotype controls before tMCAO surgery did not result in a smaller stroke size. As demonstrated by fluorescence-activated cell sorting (FACS), after stroke, iv injected nbs bound to brain-infiltrated macrophages but not to brain resident microglia, indicating insufficient crossing of the blood-brain barrier of the nbs. Therefore, we directly icv injected the P2X7-specific nbs or the isotype nbs. After icv injection of 30 µg of P2X7 specific nbs, P2X7 specific nbs bound sufficiently to microglia and reduced stroke size. CONCLUSION: Mechanistically, we can show that there is a substantial increase of ATP locally after stroke and that blockage of the ATP receptor P2X7 by icv injected P2X7-specific nbs can reduce ischemic tissue damage.

Effective targeting of microglial P2X7 following intracerebroventricular delivery of nanobodies and nanobody-encoding AAVs.

The P2X7 ion channel is a key sensor for extracellular ATP and a key trigger of sterile inflammation. Intravenous injection of nanobodies that block P2X7 has shown to be beneficial in mouse models of systemic inflammation. P2X7 has also emerged as an attractive therapeutic target for inflammatory brain diseases. However, little is known about the ability of nanobodies to cross the BBB. Here we evaluated the ability of P2X7-specific nanobodies to reach and to block P2X7 on microglia following intravenous or intracerebral administration. For this study, we reformatted and sequence-optimized P2X7 nanobodies for higher stability and elevated isoelectric point. Following injection of nanobodies or nanobody-encoding adeno-associated viral vectors (AAV), we monitored the occupancy and blockade of microglial P2X7 in vivo using ex vivo flow cytometry. Our results show that P2X7 on microglia was within minutes completely occupied and blocked by intracerebroventricularly injected nanobodies, even at low doses. In contrast, very high doses were required to achieve similar effects when injected intravenously. The endogenous production of P2X7-antagonistic nanobodies following intracerebral or intramuscular injection of nanobody-encoding AAVs resulted in a long-term occupancy and blockade of P2X7 on microglia. Our results provide new insights into the conditions for the delivery of nanobodies to microglial P2X7 and point to AAV-mediated delivery of P2X7 nanobodies as a promising strategy for the treatment of sterile brain inflammation.

P2X7 is expressed on human innate-like T lymphocytes and mediates susceptibility to ATP-induced cell death.

Extracellular ATP activates the P2X7 receptor, leading to inflammasome activation and release of pro-inflammatory cytokines in monocytes. However, a detailed analysis of P2X7 receptor expression and function in the human T cell compartment has not been reported. Here, we used a P2X7-specific nanobody to assess cell membrane expression and function of P2X7 on peripheral T lymphocyte subsets. The results show that innate-like T cells, which effectively react to innate stimuli by secreting high amounts of pro-inflammatory cytokines, have the highest expression of P2X7 in the human T cell compartment. Using Tγδ cells as example for an innate-like lymphocyte population, we demonstrate that these cells are more sensitive to P2X7 receptor activation than conventional T cells, affecting fundamental cellular mechanisms like calcium signaling and ATP-induced cell death. The increased susceptibility of innate-like T cells to P2X7-mediated cell death provides a mechanism to control their homeostasis under inflammatory conditions. Understanding the expression and function of P2X7 on human immune cells is essential to assume the benefits and consequences of newly developed P2X7-based therapeutic approaches.

Novel N-benzoylimidazolium ionic liquids derived from benzoic and hydroxybenzoic acids as therapeutic alternative against Biofilm-forming bacteria in skin and soft-tissue infections.

The skin and soft tissue infections (SSTIs) -producing pathogens have acquired resistance to a wide range of antimicrobials, thus it is highly relevant to have new treatment alternatives. In this study, we report the synthesis, characterization, and antibacterial activity of three novel series of ionic liquids (ILs) derived from benzoic and hydroxybenzoic acids, with different lengths of the alkyl chain. The minimum inhibitory concentration (MIC) were tested in Gram-positive: Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes, and Gram-negative: Acinetobacter baumannii and Escherichia coli, showing a MIC range of 0.01562-2.0 mM, with the activity varying according to the aromatic ring functionalization and the length of the alkyl chains. Regarding the antibiofilm activity, different efficacy was observed among the different ILs, some of them presenting antibiofilm activities close to 80% as in the case of those derived from syringic acid with an alkyl chain of six carbon atoms against Pseudomonas aeruginosa. Furthermore, the cell viability in HaCaT cells was determined, showing a half maximal effective concentration (EC50) values higher than the MIC values. The antimicrobial and antibiofilm results, along with not producing cellular toxicity at the MIC values shows that these ILs could be a promising alternative against SSTIs.

Relationship Between Endothelial and Angiogenesis Biomarkers Envisage Mortality in a Prospective Cohort of COVID-19 Patients Requiring Respiratory Support.

Purpose: Endothelial damage and angiogenesis are fundamental elements of neovascularisation and fibrosis observed in patients with coronavirus disease 2019 (COVID-19). Here, we aimed to evaluate whether early endothelial and angiogenic biomarkers detection predicts mortality and major cardiovascular events in patients with COVID-19 requiring respiratory support. Methods: Changes in serum syndecan-1, thrombomodulin, and angiogenic factor concentrations were analysed during the first 24 h and 10 days after COVID-19 hospitalisation in patients with high-flow nasal oxygen or mechanical ventilation. Also, we performed an exploratory evaluation of the endothelial migration process induced by COVID-19 in the patients' serum using an endothelial cell culture model. Results: In 43 patients, mean syndecan-1 concentration was 40.96 ± 106.9 ng/mL with a 33.9% increase (49.96 ± 58.1 ng/mL) at day 10. Both increases were significant compared to healthy controls (Kruskal-Wallis p < 0.0001). We observed an increase in thrombomodulin, Angiopoietin-2, human vascular endothelial growth factor (VEGF), and human hepatocyte growth factor (HGF) concentrations during the first 24 h, with a decrease in human tissue inhibitor of metalloproteinases-2 (TIMP-2) that remained after 10 days. An increase in human Interleukin-8 (IL-8) on the 10th day accompanied by high HGF was also noted. The incidence of myocardial injury and pulmonary thromboembolism was 55.8 and 20%, respectively. The incidence of in-hospital deaths was 16.3%. Biomarkers showed differences in severity of COVID-19. Syndecan-1, human platelet-derived growth factor (PDGF), VEGF, and Ang-2 predicted mortality. A multiple logistic regression model with TIMP-2 and PDGF had positive and negative predictive powers of 80.9 and 70%, respectively, for mortality. None of the biomarkers predicted myocardial injury or pulmonary thromboembolism. A proteome profiler array found changes in concentration in a large number of biomarkers of angiogenesis and chemoattractants. Finally, the serum samples from COVID-19 patients increased cell migration compared to that from healthy individuals. Conclusion: We observed that early endothelial and angiogenic biomarkers predicted mortality in patients with COVID-19. Chemoattractants from patients with COVID-19 increase the migration of endothelial cells. Trials are needed for confirmation, as this poses a therapeutic target for SARS-CoV-2.

The Immune Response to SARS-CoV-2: Mechanisms, Aging, Sequelae, and Vaccines.

This review seeks to clarify the factors involved in the various immune responses to SARSCoV- 2 infection and the mechanisms that influence the development of COVID-19 with severe evolution. The innate immune response that evolves against SARS-CoV-2 in a complex way is highlighted, integrating multiple pathways by coronaviruses to evade it, in addition to characterizing the adaptive immune response, which can lead to an effective immune response or can contribute to immunopathological imbalance. In turn, host-dependent biomarkers, such as age, gender, ABO blood group, and risk factors, that contribute to the critical and varied progress of COVID-19 immunopathogenesis are analyzed. Finally, the potential vaccine candidates are presented, capable of generating immune protection with humoral and/or cellular neutralizing responses, in favor of blocking and destroying both the new human coronavirus and its variants, which cause the current pandemic.

A simplified alternative diagnostic algorithm for SARS-CoV-2 suspected symptomatic patients and confirmed close contacts (asymptomatic): A consensus of Latin American experts.

INTRODUCTION: Latin America accounts for one-quarter of global COVID-19 cases and one-third of deaths. Inequalities in the region lead to barriers to the best use of diagnostic tests during the pandemic. There is a need for simplified guidelines that consider the region's limited health resources, international guidelines, medical literature, and local expertise. METHODS: Using a modified Delphi method, 9 experts from Latin American countries developed a simplified algorithm for COVID-19 diagnosis on the basis of their answers to 24 questions related to diagnostic settings, and discussion of the literature and their experiences. RESULTS: The algorithm considers 3 timeframes (≤7 days, 8-13 days, and ≥14 days) and presents diagnostic options for each. SARS-CoV-2 real- time reverse transcription-polymerase chain reaction is the test of choice from day 1 to 14 after symptom onset or close contact, although antigen testing may be used in specific circumstances, from day 5 to 7. Antibody assays may be used for confirmation, usually after day 14; however, if clinical suspicion is very high, but other tests are negative, these assays may be used as an adjunct to decision-making from day 8 to 13. CONCLUSION: The proposed algorithm aims to support COVID-19 diagnosis decision-making in Latin America.

Efficiency of Thermally Activated Delayed Fluorescence Sensitized Triplet Upconversion Doubled in Three-Component System.

As in many fields, the most exciting endeavors in photon upconversion research focus on increasing the efficiency (upconversion quantum yield) and performance (anti-Stokes shift) while diminishing the cost of production. In this vein, studies employing metal-free thermally activated delayed fluorescence (TADF) sensitizers have garnered increased interest. Here, for the first time, the strategy of ternary photon upconversion is utilized with the TADF sensitizer 2,4,5,6-tetrakis(carbazol-9-yl)isophthalonitrile (4CzIPN), resulting in a doubling of the upconversion quantum yield in comparison to the binary system employing p-terphenyl as the emitter. In this ternary blend, the sensitizer 4CzIPN is paired with an intermediate acceptor, 1-methylnaphthalene, in addition to the emitter molecule, p-terphenyl, yielding a normalized upconversion quantum yield of 7.6% while maintaining the 0.83 eV anti-Stokes shift. These results illustrate the potential benefits of utilizing this strategy of energy-funneling, previously used only with heavy-metal based sensitizers, to increase the performance of these photon upconversion systems.

A Methodological Approach Using rAAV Vectors Encoding Nanobody-Based Biologics to Evaluate ARTC2.2 and P2X7 In Vivo.

On murine T cells, mono-ADP ribosyltransferase ARTC2.2 catalyzes ADP-ribosylation of various surface proteins when nicotinamide adenine dinucleotide (NAD+) is released into the extracellular compartment. Covalent ADP-ribosylation of the P2X7 receptor by ARTC2.2 thereby represents an additional mechanism of activation, complementary to its triggering by extracellular ATP. P2X7 is a multifaceted receptor that may represents a potential target in inflammatory, and neurodegenerative diseases, as well as in cancer. We present herein an experimental approach using intramuscular injection of recombinant AAV vectors (rAAV) encoding nanobody-based biologics targeting ARTC2.2 or P2X7. We demonstrate the ability of these in vivo generated biologics to potently and durably block P2X7 or ARTC2.2 activities in vivo, or in contrast, to potentiate NAD+- or ATP-induced activation of P2X7. We additionally demonstrate the ability of rAAV-encoded functional heavy chain antibodies to elicit long-term depletion of T cells expressing high levels of ARTC2.2 or P2X7. Our approach of using rAAV to generate functional nanobody-based biologics in vivo appears promising to evaluate the role of ARTC2.2 and P2X7 in murine acute as well as chronic disease models.

Cutaneous Leishmaniasis in an Immunocompromised Pediatric Patient With Acute Lymphoblastic Leukemia.

Leishmaniasis is a protozoan disease caused by the parasite Leishmania. It is most common in developing countries. Its clinical presentation varies depending on several factors such as patient's immunity. Cutaneous leishmaniasis is one of the main types of leishmaniasis, it is known to be a great mimicker. When seen in immunodeficient populations, such as patients with acute lymphoblastic leukemia, it may present more aggressively and its diagnosis is challenging. We present a case of a five-year-old male with a history of acute lymphoblastic leukemia undergoing chemotherapy who developed papules evolving into ulcerated nodules on his left lower extremity. An initial smear for leishmaniasis was negative, the disease evolved and spread in an ascending fashion, while efforts were made finding a diagnosis. One-month later the smear was repeated and positive for leishmaniasis. Subsequently, therapy with Meglumine antimoniate was prescribed. The lesions healed with atrophic scarring without complications. Cutaneous leishmaniasis diagnostic methods are not standardized, limitations such as interpreter's expertise and patient's immunity state may play a role in delaying the diagnosis.

Hábito de higiene de manos y patógenos hallados en estudiantes de medicina / Hand Hygiene Habit And Pathogens Found In Medical Students

La higiene de manos se hace indispensable cuando existe la posibilidad de la presencia de cepas patógenas. El objetivo fue conocer los hábitos de higiene de manos de los estudiantes de medicina; así como la población bacteriana residente en la palma de las manos. Se llevo a cabo un estudio observacional, descriptivo de tipo transversal, y se realizó una encuesta sobre la conducta de higiene de manos a 100 alumnos, y a otros 33 alumnos se les realizó cultivo microbiológico de la superficie palmar. En relación a los hábitos de higiene, la conducta el 70% tiene una frecuencia de lavarse las manos apropiada, el 88% se lava las manos luego del uso de los servicios higiénicos; y el 64 % se lava las manos antes de tomar los alimentos. La actitud a la higiene, el 28% no consume alimentos en ambulantes, el 32% se lava las manos al llegar a casa, y el 64% de los estudiantes se llevan la mano a la boca o nariz en forma ocasional. En prevención de contagio con el uso de antibacterianos es apropiada en el 31%; el cuidado de las uñas es apropiado en el 63%; y el uso de guantes durante las prácticas de laboratorio es apropiado en el 44%. Se aislaron los siguientes microorganismos patógenos: S.aureus con 20 casos (60.6 %), P. aeruginosa, Enterobacter y S.viridans, uno en cada caso. Por lo tanto, deben organizarse talleres o campañas de difusión para concientizar y modular los hábitos de higiene de manos en los alumnos.

The objective was to know the hand hygiene habits of medical students; as well as the bacterial population resident in the palm of the hands. An observational, descriptive cross-sectional study was carried out. Likewise, a hand hygiene behavior survey was carried out on 100 students, and a microbiological culture of the palmar surface was carried out on 33 other students. Regarding hygiene habits, 74% showed an appropriate attitude. The hygiene attitude was appropriate in 41.3% and 46% in relation to the prevention of contagion. The following pathogenic microorganisms were isolated: S.aureus with 20 cases (60.6%), P. aeruginosa, Enterobacter and S.viridans, one in each case. Therefore, workshops or dissemination campaigns should be organized to raise awareness and modulate hand hygiene habits in students.

Evaluation of P2X7 Receptor Function in Tumor Contexts Using rAAV Vector and Nanobodies (AAVnano).

Adenosine triphosphate (ATP) represents a danger signal that accumulates in injured tissues, in inflammatory sites, and in the tumor microenvironment. Extracellular ATP is known to signal through plasma membrane receptors of the P2Y and P2X families. Among the P2X receptors, P2X7 has attracted increasing interest in the field of inflammation as well as in cancer. P2X7 is expressed by immune cells and by most malignant tumor cells where it plays a crucial yet complex role that remains to be clarified. P2X7 activity has been associated with production and release of pro-inflammatory cytokines, modulation of the activity and survival of immune cells, and the stimulation of proliferation and migratory properties of tumor cells. Hence, P2X7 plays an intricate role in the tumor microenvironment combining beneficial and detrimental effects that need to be further investigated. For this, we developed a novel methodology termed AAVnano based on the use of Adeno-associated viral vectors (AAV) encoding nanobodies targeting P2X7. We discuss here the advantages of this tool to study the different functions of P2X7 in cancer and other pathophysiological contexts.

Current Approaches and Future Perspectives for Nanobodies in Stroke Diagnostic and Therapy.

Antibody-based biologics are the corner stone of modern immunomodulatory therapy. Though highly effective in dampening systemic inflammatory processes, their large size and Fc-fragment mediated effects hamper crossing of the blood brain barrier (BBB). Nanobodies (Nbs) are single domain antibodies derived from llama or shark heavy-chain antibodies and represent a new generation of biologics. Due to their small size, they display excellent tissue penetration capacities and can be easily modified to adjust their vivo half-life for short-term diagnostic or long-term therapeutic purposes or to facilitate crossing of the BBB. Furthermore, owing to their characteristic binding mode, they are capable of antagonizing receptors involved in immune signaling and of neutralizing proinflammatory mediators, such as cytokines. These qualities combined make Nbs well-suited for down-modulating neuroinflammatory processes that occur in the context of brain ischemia. In this review, we summarize recent findings on Nbs in preclinical stroke models and how they can be used as diagnostic and therapeutic reagents. We further provide a perspective on the design of innovative Nb-based treatment protocols to complement and improve stroke therapy.

Novel biologics targeting the P2X7 ion channel.

Targeting the P2X7 ion channel, a danger sensor for extracellular nucleotides, improves outcomes in models of inflammation, cancer, and brain-diseases. Antibodies and nanobodies have been developed that antagonize or potentiate gating of P2X7. Their potential advantages over small-molecule drugs include high specificity, lower off-target effects, and tunable in vivo half-life. Genetic fusion of P2X7-specific biologics to binding modules may enable targeting of specific cell subsets. Besides directly modulating P2X7 function, antibodies can also initiate specific depletion of P2X7-expressing cells. Adeno-associated viral vectors (AAV) can be used to express P2X7-specific antibodies in vivo to achieve long-lasting biological effects. Furthermore, if successfully targeted to P2X7-expressing cells, AAVs may enable modulation of the function of P2X7-expressing immune cells via encoded transgenic RNA or proteins.

[Vibrio cholerae NO-O1/NO-O139 bacteremia in a cirrhotic patient. First case report in Peru and literatura review]. / Bacteremia por Vibrio cholerae NO-O1/NO-O139 en un paciente cirrótico. Primer reporte de caso en el Perú y revisión de la literatura.

Non-O1, non-O139 Vibrio cholerae (NOVC) strains are an uncommon cause of gastroenteritis. However, they have been recently associated with severe extraintestinal infections in immunocompromised hosts. Among them, bacteremia in cirrhotic patients is noteworthy. We present the case of a 58-year-old woman with cirrhosis that developed septic shock, multiple organ failure and died four days after admission. Blood cultures yielded Gram-negative rods identified as Vibrio cholerae. Further serogrouping by slide agglutination and a negative PCR for ctxA gen confirmed the strain to be NOVC. Antimicrobial susceptibility testing showed sensitivity to ampicillin, chloramphenicol, tetracycline and ciprofloxacin; and resistance to trimethoprim-sulfamethoxazole. To the best of our knowledge, this is first report in Peru, described in the Hospital Nacional Dos de Mayo, of NOVC bacteremia.