Optical Actuation of Nanoparticle-Loaded Liquid-Liquid Interfaces for Active Photonics.

Liquid-liquid interfaces hold the potential to serve as versatile platforms for dynamic processes, due to their inherent fluidity and capacity to accommodate surface-active materials. This study explores laser-driven actuation of liquid-liquid interfaces with and without loading of gold nanoparticles and further exploits the laser-actuated interfaces with nanoparticles for tunable photonics. Upon laser exposure, gold nanoparticles were rearranged along the interface, enabling the reconfigurable, small-aperture modulation of light transmission and the tunable lensing effect. Adapting the principles of optical and optothermal tweezers, we interpreted the underlying mechanisms of actuation and modulation as a synergy of optomechanical and optothermal effects. Our findings provide an analytical framework for understanding microscopic interfacial behaviors, contributing to potential applications in tunable photonics and interfacial material engineering.

Amelioration of morphine withdrawal syndrome by systemic and intranasal administration of mesenchymal stem cell-derived secretome in preclinical models of morphine dependence.

BACKGROUND: Morphine is an opiate commonly used in the treatment of moderate to severe pain. However, prolonged administration can lead to physical dependence and strong withdrawal symptoms upon cessation of morphine use. These symptoms can include anxiety, irritability, increased heart rate, and muscle cramps, which strongly promote morphine use relapse. The morphine-induced increases in neuroinflammation, brain oxidative stress, and alteration of glutamate levels in the hippocampus and nucleus accumbens have been associated with morphine dependence and a higher severity of withdrawal symptoms. Due to its rich content in potent anti-inflammatory and antioxidant factors, secretome derived from human mesenchymal stem cells (hMSCs) is proposed as a preclinical therapeutic tool for the treatment of this complex neurological condition associated with neuroinflammation and brain oxidative stress. METHODS: Two animal models of morphine dependence were used to evaluate the therapeutic efficacy of hMSC-derived secretome in reducing morphine withdrawal signs. In the first model, rats were implanted subcutaneously with mini-pumps which released morphine at a concentration of 10 mg/kg/day for seven days. Three days after pump implantation, animals were treated with a simultaneous intravenous and intranasal administration of hMSC-derived secretome or vehicle, and withdrawal signs were precipitated on day seven by i.p. naloxone administration. In this model, brain alterations associated with withdrawal were also analyzed before withdrawal precipitation. In the second animal model, rats voluntarily consuming morphine for three weeks were intravenously and intranasally treated with hMSC-derived secretome or vehicle, and withdrawal signs were induced by morphine deprivation. RESULTS: In both animal models secretome administration induced a significant reduction of withdrawal signs, as shown by a reduction in a combined withdrawal score. Secretome administration also promoted a reduction in morphine-induced neuroinflammation in the hippocampus and nucleus accumbens, while no changes were observed in extracellular glutamate levels in the nucleus accumbens. CONCLUSION: Data presented from two animal models of morphine dependence suggest that administration of secretome derived from hMSCs reduces the development of opioid withdrawal signs, which correlates with a reduction in neuroinflammation in the hippocampus and nucleus accumbens.

Chronic Voluntary Morphine Intake Is Associated with Changes in Brain Structures Involved in Drug Dependence in a Rat Model of Polydrug Use.

Chronic opioid intake leads to several brain changes involved in the development of dependence, whereby an early hedonistic effect (liking) extends to the need to self-administer the drug (wanting), the latter being mostly a prefrontal-striatal function. The development of animal models for voluntary oral opioid intake represents an important tool for identifying the cellular and molecular alterations induced by chronic opioid use. Studies mainly in humans have shown that polydrug use and drug dependence are shared across various substances. We hypothesize that an animal bred for its alcohol preference would develop opioid dependence and further that this would be associated with the overt cortical abnormalities clinically described for opioid addicts. We show that Wistar-derived outbred UChB rats selected for their high alcohol preference additionally develop: (i) a preference for oral ingestion of morphine over water, resulting in morphine intake of 15 mg/kg/day; (ii) marked opioid dependence, as evidenced by the generation of strong withdrawal signs upon naloxone administration; (iii) prefrontal cortex alterations known to be associated with the loss of control over drug intake, namely, demyelination, axonal degeneration, and a reduction in glutamate transporter GLT-1 levels; and (iv) glial striatal neuroinflammation and brain oxidative stress, as previously reported for chronic alcohol and chronic nicotine use. These findings underline the relevance of polydrug animal models and their potential in the study of the wide spectrum of brain alterations induced by chronic morphine intake. This study should be valuable for future evaluations of therapeutic approaches for this devastating condition.

Pneumocystis Exacerbates Inflammation and Mucus Hypersecretion in a Murine, Elastase-Induced-COPD Model.

Inflammation and mucus hypersecretion are frequent pathology features of chronic respiratory diseases such as asthma and COPD. Selected bacteria, viruses and fungi may synergize as co-factors in aggravating disease by activating pathways that are able to induce airway pathology. Pneumocystis infection induces inflammation and mucus hypersecretion in immune competent and compromised humans and animals. This fungus is a frequent colonizer in patients with COPD. Therefore, it becomes essential to identify whether it has a role in aggravating COPD severity. This work used an elastase-induced COPD model to evaluate the role of Pneumocystis in the exacerbation of pathology, including COPD-like lung lesions, inflammation and mucus hypersecretion. Animals infected with Pneumocystis developed increased histology features of COPD, inflammatory cuffs around airways and lung vasculature plus mucus hypersecretion. Pneumocystis induced a synergic increment in levels of inflammation markers (Cxcl2, IL6, IL8 and IL10) and mucins (Muc5ac/Muc5b). Levels of STAT6-dependent transcription factors Gata3, FoxA3 and Spdef were also synergically increased in Pneumocystis infected animals and elastase-induced COPD, while the levels of the mucous cell-hyperplasia transcription factor FoxA2 were decreased compared to the other groups. Results document that Pneumocystis is a co-factor for disease severity in this elastase-induced-COPD model and highlight the relevance of STAT6 pathway in Pneumocystis pathogenesis.

Optothermal rotation of micro-/nano-objects.

Due to its contactless and fuel-free operation, optical rotation of micro-/nano-objects provides tremendous opportunities for cellular biology, three-dimensional (3D) imaging, and micro/nanorobotics. However, complex optics, extremely high operational power, and the applicability to limited objects restrict the broader use of optical rotation techniques. This Feature Article focuses on a rapidly emerging class of optical rotation techniques, termed optothermal rotation. Based on light-mediated thermal phenomena, optothermal rotation techniques overcome the bottlenecks of conventional optical rotation by enabling versatile rotary control of arbitrary objects with simpler optics using lower powers. We start with the fundamental thermal phenomena and concepts: thermophoresis, thermoelectricity, thermo-electrokinetics, thermo-osmosis, thermal convection, thermo-capillarity, and photophoresis. Then, we highlight various optothermal rotation techniques, categorizing them based on their rotation modes (i.e., in-plane and out-of-plane rotation) and the thermal phenomena involved. Next, we explore the potential applications of these optothermal manipulation techniques in areas such as single-cell mechanics, 3D bio-imaging, and micro/nanomotors. We conclude the Feature Article with our insights on the operating guidelines, existing challenges, and future directions of optothermal rotation.

Optothermal rotation of micro-/nano-objects in liquids.

Controllable rotation of micro-/nano-objects provides tremendous opportunities for cellular biology, three-dimensional (3D) imaging, and micro/nanorobotics. Among different rotation techniques, optical rotation is particularly attractive due to its contactless and fuel-free operation. However, optical rotation precision is typically impaired by the intrinsic optical heating of the target objects. Optothermal rotation, which harnesses light-modulated thermal effects, features simpler optics, lower operational power, and higher applicability to various objects. In this Feature Article, we discuss the recent progress of optothermal rotation with a focus on work from our research group. We categorize the various rotation techniques based on distinct physical mechanisms, including thermophoresis, thermoelectricity, thermo-electrokinetics, thermo-osmosis, thermal convection, and thermo-capillarity. Benefiting from the different rotation modes (i.e., in-plane and out-of-plane rotation), diverse applications in single-cell mechanics, 3D bio-imaging, and micro/nanomotors are demonstrated. We conclude the article with our perspectives on the operating guidelines, existing challenges, and future directions of optothermal rotation.

PALB2 germline mutations in a multi-gene panel testing cohort of 1905 breast-ovarian cancer patients in Argentina.

PURPOSE: PALB2 variants have been scarcely described in Argentinian and Latin-American reports. In this study, we describe molecular and clinical characteristics of PALB2 mutations found in multi-gene panels (MP) from breast-ovarian cancer (BOC) families in different institutions from Argentina. METHODS: We retrospectively identified PALB2 pathogenic (PV) and likely pathogenic (LPV) variants from a cohort of 1905 MP results, provided by one local lab (Heritas) and SITHER (Hereditary Tumor Information System) public database. All patients met hereditary BOC clinical criteria for testing, according to current guidelines. RESULTS: The frequency of PALB2 mutations is 2.78% (53/1905). Forty-eight (90.5%) are PV and five (9.5%) are LPV. Most of the 18 different mutations (89%) are nonsense and frameshift types and 2 variants are novel. One high-rate recurrent PV (Y551*) is present in 43% (23/53) of the unrelated index cases. From the 53 affected carriers, 94% have BC diagnosis with 14% of bilateral cases. BC phenotype is mainly invasive ductal (78%) with 62% of hormone-receptor positive and 22% of triple negative tumors. Self-reported ethnic background of the cohort is West European (66%) and native Latin-American (20%) which is representative of Buenos Aires and other big urban areas of the country. CONCLUSION: This is the first report describing molecular and clinical characteristics of PALB2 carriers in Argentina. Frequency of PALB2 PV in Argentinian HBOC families is higher than in other reported populations. Y551* is a recurrent mutation that seems to be responsible for almost 50% of PALB2 cases.

A Novel Morphine Drinking Model of Opioid Dependence in Rats.

An animal model of voluntary oral morphine consumption would allow for a pre-clinical evaluation of new treatments aimed at reducing opioid intake in humans. However, the main limitation of oral morphine consumption in rodents is its bitter taste, which is strongly aversive. Taste aversion is often overcome by the use of adulterants, such as sweeteners, to conceal morphine taste or bitterants in the alternative bottle to equalize aversion. However, the adulterants' presence is the cause for consumption choice and, upon removal, the preference for morphine is not preserved. Thus, current animal models are not suitable to study treatments aimed at reducing consumption elicited by morphine itself. Since taste preference is a learned behavior, just-weaned rats were trained to accept a bitter taste, adding the bitterant quinine to their drinking water for one week. The latter was followed by allowing the choice of quinine or morphine (0.15 mg/mL) solutions for two weeks. Then, quinine was removed, and the preference for morphine against water was evaluated. Using this paradigm, we show that rats highly preferred the consumption of morphine over water, reaching a voluntary morphine intake of 15 mg/kg/day. Morphine consumption led to significant analgesia and hyperlocomotion, and to a marked deprivation syndrome following the administration of the opioid antagonist naloxone. Voluntary morphine consumption was also shown to generate brain oxidative stress and neuroinflammation, signs associated with opioid dependence development. We present a robust two-bottle choice animal model of oral morphine self-administration for the evaluation of therapeutic interventions for the treatment of morphine dependence.

Cyclin-Dependent Kinase 4/6 Inhibitor Outcomes in Patients With Advanced Breast Cancer Carrying Germline Pathogenic Variants in DNA Repair-Related Genes.

PURPOSE: In recent years, unprecedented benefits have been observed with the development of cyclin-dependent kinase (CDK) 4 and 6 inhibitors for the treatment of hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer. However, there is scarce evidence of their value in specific populations, such as patients carrying germline pathogenic variants in DNA repair-related genes. PATIENTS AND METHODS: We retrospectively studied the efficacy of CDK 4/6 inhibitors plus endocrine therapy in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer. Three cohorts were compared, including patients harboring germline pathogenic variants in DNA repair-related genes (gBRCA1/2-ATM-CHEK2 mutated), those tested without these mutations (wild type [WT]), and the nontested subgroup. Relevant prognostic factors including age, metastatic site (visceral v nonvisceral), Eastern Cooperative Oncology Group, and prior treatment with CDK 4/6 inhibitors were stratified by univariate and multivariate Cox regression models. RESULTS: Among the total population (n = 217), 15 (6.9%) patients carried gBRCA1/2 (n = 10)-ATM (n = 4)-CHEK2 (n = 1) pathogenic variants, 45 (20.7%) were WT, and 157 (72.4%) were nontested. Gene pathogenic variant carriers were younger (P < .001). Most patients (164, 75.6%) had not received prior endocrine therapy in the advanced setting. Median progression-free survival was shorter in patients with evaluated germline pathogenic variants (10.2 months [95% CI, 5.7 to 14.7]), compared with WT and nontested patients (15.6 months [95% CI, 7.8 to 23.4], and (17.6 months [95% CI, 12.9 to 22.2]; P = .002). Consistently, a worse median overall survival was observed in the subgroup with germline pathogenic variants than in the WT group (P = .006). Multivariable analysis showed that mutation status was an independent prognostic factor of progression-free survival (P = .020) and overall survival (P = .012). CONCLUSION: In this retrospective real-world study, gBRCA1/2-ATM-CHEK2 pathogenic variants were independently associated with poor outcomes in patients with advanced breast cancer treated with CDK4/6 inhibitors.

¿Cuál es el impacto emocional de los resultados de estudios genéticos en pacientes oncológicos con sospecha de síndrome hereditario para cáncer? / What is the emotional impact of the genetic test results on oncologic patients with suspected hereditary cancer syndrome?

Objetivos: valorar el impacto emocional de recibir los resultados del estudio genético (EG) en pacientes con antecedente oncológico personal y sospecha de síndrome hereditario, aplicando el Cuestionario Multidimensional del Impacto de la evaluación de riesgo de cáncer (MICRA). Método: 219 pacientes con diagnóstico oncológico que concurrieron a la consulta de Asesoramiento Genético Oncológico en el Instituto Alexander Fleming entre 2014 y 2019, fueron evaluados aplicando el MICRA. Resultados: Edad promedio 49,84 (42,21; 62,02), 82,2% con diagnóstico de cáncer de mama. En un 16% se halló una variante patogénica (VP). La media de los puntajes obtenidos por cada subescala fue: 5,26 (DS=4,48, rango 0-22) para Malestar Emocional (ME); 12,31 (DS 7,42 rango 0-37) para Incertidumbre (I); 16,36 (DS 4.30 rango 2-20) para Experiencias Positivas (EP) y de 34,37 (DS 10,24 rango 8-62) para la puntuación global, lo que muestra un bajo nivel de ME e I y la presencia de EP entre los pacientes. Se hallaron diferencias significativas según tipo de resultado: los portadores de VP, mostraron una modesta elevación del nivel de ME y menor puntuación en EP, respecto de aquellos que tuvieron resultados no informativos o inciertos. Sin diferencias significativas según edad, pacientes con o sin hijos, o tiempo entre la realización del estudio y la aplicación del cuestionario. Conclusiones: Recibir resultados de estudio genético no produciría un impacto psicológico adverso. Las puntuaciones altas de esta escala podrían ser usadas para identificar a pacientes con malestar emocional y ofrecerles un seguimiento psicooncológico específico (AU)

Objective: The aim of our study is to assess the emotional impact of genetic test results disclosure to patients with a personal cancer history and suspected hereditary syndrome, applying the Multidimensional Impact of Cancer Risk Assessment (MICRA) Questionnaire. Methods: two hundred nineteen patients affected with cancer, referred to the Cancer Genetic Counseling department at the Alexander Fleming Institute, between 2014 and 2019, were evaluated using the MICRA questionnaire. Results: Average age 49.84 (42,21; 62,02), 82.2% presented breast cancer. In 16% a pathogenic variant (PV) was found. The mean of the scores obtained for each subscale in the questionnaire was 5.26 (0-22, SD 4.48) for Distress (D); 12.31 (0-37, DS 7.42) for Uncertainty (U); 16.36 (2-20 SD 4.30) for Positive Experiences (PE) and 34.37 (8-62 SD 10.24) for the global score, which shows a low level of D and U and the presence of PE among the patients. Significant differences were found according to the type of result: We found modestly increased distress in PV carriers compared to patients who received uninformative or negative test results. No significant differences according to age, patients with or without children, or time between the completion of the genetic test and the application of the questionnaire. Conclusion: Genetic test disclosure does not seem to produce an adverse psychological impact. High scores on this scale could be used to identify patients with emotional distress and offer them specific psycho-oncological follow-up (AU)

Sero-Epidemiology of Pneumocystis Infection among Infants, Children, and Adults in Chile.

Previous serologic surveys show >80% of infants in Chile have anti-Pneumocystis antibodies by 2 years of age, but the seroepidemiology of Pneumocystis infection beyond infancy is unknown. We describe the sero-epidemiology in infants, children, and adults at different locations in Chile. Serum samples were prospectively obtained from 681 healthy adults (age ≥ 17 years) and 690 non-immunocompromised infants/children attending eight blood banks or outpatient clinics (2 in Santiago) in Chile. ELISA was used to measure serum IgM and IgG antibodies to Pneumocystis jirovecii major surface antigen (Msg) constructs MsgA and MsgC1. Serologic responses to Pneumocystis Msg showed a high frequency of reactivity, inferring infection. Among infants/children increasing age and the proportion with detectable IgM responses to MsgA, and IgG responses to MsgA, and MsgC1 were positively associated. Among adults there was almost universal seropositivity to one or more Pneumocystis Msg constructs. In infants and children rates of detectable IgM responses to MsgC1 and MsgA were greater than IgG responses. In Santiago, rates of seropositivity among infants/children were greater in clinics located in a more socio-economically deprived part of the city. In Chile, a serological response to Pneumocystis Msg constructs was common across ages regardless of geographical location and climatic conditions. Observed higher rates of IgM responses than IgG responses is consistent with concept of recent/ongoing exposure to Pneumocystis in children and adults. Higher rates of seropositivity in infants/children residing in more densely populated areas of Santiago infers crowding poses an increased risk of transmission.

Pneumocystis primary infection in non-immunosuppressed infants in Lima, Peru.

OBJECTIVES: To provide original data on Pneumocystis primary infection in non-immunosuppressed infants from Peru. METHODS: A cross sectional study was performed. Infants less than seven months old, without any underlying medical conditions attending the "well baby" outpatient clinic at one hospital in Lima, Peru were prospectively enrolled during a 15-month period from November 2016 to February 2018. All had a nasopharyngeal aspirate (NPA) for detection of P. jirovecii DNA using a PCR assay, regardless of respiratory symptoms. P. jirovecii DNA detection was considered to represent pulmonary colonization contemporaneous with Pneumocystis primary infection. Associations between infants' clinical and demographic characteristics and results of P. jirovecii DNA detection were analyzed. RESULTS: P. jirovecii DNA was detected in 45 of 146 infants (30.8%) and detection was not associated with concurrent respiratory symptoms in 40 of 45 infants. Infants with P. jirovecii had a lower mean age when compared to infants not colonized (p <0.05). The highest frequency of P. jirovecii was observed in 2-3-month-old infants (p < 0.01) and in the cooler winter and spring seasons (p <0.01). Multivariable analysis showed that infants living in a home with ≤ 1 bedroom were more likely to be colonized; Odds Ratio =3.03 (95%CI 1.31-7.00; p = 0.01). CONCLUSION: Pneumocystis primary infection in this single site in Lima, Peru, was most frequently observed in 2-3-month-old infants, in winter and spring seasons, and with higher detection rates being associated with household conditions favoring close inter-individual contacts and potential transmission of P. jirovecii.

Valor de la ruptura capsular y extensión extranodal en el ganglio centinela como predictores del estado axilar en pacientes con cáncer de mama T1-T2 / Significance of extracapsular extension in sentinel lymph nodes as a predictor of axillary lymph node status in T1-T2 breast cancer patients

Introducción: Identificar aquellas pacientes con cáncer de mama en estadíos iniciales que no se benefician de la linfadenectomía (LA), a pesar de contar con ganglios centinela positivos, constituye un desafío. El ensayo ACOSOG-Z0011 modificó el paradigma de la cirugía axilar, pero aún no está claro qué efecto tiene la ruptura capsular (RC) y su extensión (EEC) en el compromiso axilar. Material y método: Se incluyeron 214 pacientes intervenidas quirúrgicamente entre 2009-2019 en el Centro mamario del Instituto Alexander Fleming, con cáncer de mama en T1-2, en las que la biopsia de ganglio centinela (BGC) resultó positiva, y se realizó LA. Se realizaron comparaciones entre aquellas pacientes con y sin RC. Las pacientes con RC fueron divididas en dos grupos, según la EEC fuera mayor o igual a 2 mm, o menor a 2 mm. Para los distintos grupos de pacientes, se analizaron variables clínicas y anatomo-patológicas, incluyendo edad, estado menopáusico, subtipo biológico, grado nuclear, tamaño tumoral, invasión linfovascular (ILV) y multicentricidad. Resultados: La RC se asoció a una mayor probabilidad de presentar ganglios no centinela positivos, y en particular a la presencia de 4 o más ganglios positivos. Este grupo de pacientes presentó con más frecuencia ILV. En cuanto a la EEC, no hallamos diferencias significativas de acuerdo a la extensión de la ruptura (EEC<2 mm y EEC≥2 mm), aunque en el análisis uni y multivariado evidenció un mayor riesgo de presentar ≥4 ganglios positivos en el grupo de pacientes con EEC≥2 mm. Discusión: En línea con la bibliografía actual, encontramos que la RC es un hallazgo frecuente y que se asocia a una mayor probabilidad de presentar metástasis ganglionar, en especial 4 o más ganglios positivos. Al separar a las pacientes de acuerdo a la EEC, no hallamos diferencias en cuanto a la proporción de pacientes con ganglios positivos en la LA. Estos resultados difieren de los obtenidos por otros centros, en donde se ha demostrado una mayor probabilidad de contar con ganglios no centinela positivos en el grupo de pacientes con EEC>2mm. Conclusiones: En la bibliografía actual existe consenso en relación al rol de la RC como factor de riesgo, y nuestros resultados apoyan esta hipótesis. Sin embargo, resulta menos claro el papel que juega la magnitud de la EEC. Esto podría deberse, por un lado, a la falta que bibliografía disponible, y por otro, a la falta de consenso para determinar la medición de la EEC En línea con publicaciones recientes que no hallan diferencias significativas en la recurrencia de la enfermedad a largo plazo según la magnitud de la EEC, será fundamental continuar con un futuro análisis que contemple estos aspectos en nuestra población. Al día de hoy, no contamos con evidencia que nos permita afirmar que las pacientes con EEC<2 mm puedan beneficiarse de la omisión de LA

Introduction: The identification of those early breast cancer patients with no clear benefit from axillary lymph node dissection (ALND) in spite of the presence of positive sentinel lymph nodes (SLNs), remains controversial. Although the ACOSOG-Z001 trial has significantly altered management of the axilla, the role played by the extracapsular extension (ECE) is still a subject of debate. Materials and method: In the present study, we analysed 214 early breast cancer patients with positive SLN biopsy, who underwent ALND at Instituto Alexander Fleming between 2009 and 2019. Patients were divided into two categories based on the presence or absence of ECE; those patients with ECE were further divided based on the extent of ECE (ECE<2 mm and ECE≥2 mm). Analysis of clinical-pathological parameters was performed, including age, menopausal status, tumor subtype, nuclear grade, tumor size, lymphovascular invasion (LVI) and multicentricity. Results: ECE was associated with an increased probability of additional positive nodes in the ALND, and these patients were also more likely to have 24 positive nodes. LVI was increased in patients with ECE. Additionally, we found no significant differences regarding the number of positive nodes when comparing patients according to the extent of ECE (ECE<2 mm and ECE≥2 mm). Univariate and multivariate analyses of factors associated with involvement of ≥4 nodes at completion ALND resulted in an increased odds ratio for patients with ECE ≥2 mm. Discussion: In line with recent literature, we found ECE is frequently observed in breast cancer patients and is associated with an increased probability of lymph node metastases, and these patients are also more likely to have 24 positive nodes. We found no significant differences in terms of the proportion of patients with positive lymph nodes in ALND when comparing patients with and without ECE. Our results differ from other studies that showed a higher risk of non-sentinel lymph nodes metastases in patients with ECE>2mm. Conclussions: There is cumulative evidence on the role of ECE as a risk factor in breast cancer patients, and our findings further support this hypothesis. However, the extent of ECE is still a topic of heated debate, and its role in disease progression is less clear, given there are relatively few studies addressing this matter and there are discrepancies in the way the extent of ECE is measured. Considering recent publications where no significant differences were found in terms of longterm disease recurrence when stratifying patients according to the extent of ECE, our future endeavours should focus on the assessment of the course of the disease. To date, we have no evidence supporting the idea that patients with ECE<2mm could actually benefit from omis- sion of ALND.

Detection of Antibodies to Lokern, Main Drain, St. Louis Encephalitis, and West Nile Viruses in Vertebrate Animals in Chihuahua, Guerrero, and Michoacán, Mexico.

We conducted serologic surveillance for flaviviruses and orthobunyaviruses in vertebrate animals in Mexico in 2018-2019. Sera were collected from 856 vertebrate animals, including 323 dogs, 223 horses, and 121 cows, from 16 species. The animals were from 3 states: Chihuahua in northwest Mexico (704 animals) and Guerrero and Michoacán on the Pacific Coast (27 and 125 animals, respectively). Sera were assayed by plaque reduction neutralization test using four flaviviruses (dengue type 2, St. Louis encephalitis, West Nile, and Zika viruses) and six orthobunyaviruses from the Bunyamwera (BUN) serogroup (Cache Valley, Lokern, Main Drain, Northway, Potosi, and Tensaw viruses). Antibodies to West Nile virus (WNV) were detected in 154 animals of 9 species, including 89 (39.9%) horses, 3 (21.4%) Indian peafowl, and 41 (12.7%) dogs. Antibodies to St. Louis encephalitis virus (SLEV) were detected in seven animals, including three (0.9%) dogs. Antibodies to Lokern virus (LOKV) were detected in 22 animals: 19 (8.5%) horses, 2 (1.7%) cows, and a dog (0.3%). Antibodies to Main Drain virus (MDV) were detected in three (1.3%) horses. WNV and LOKV activity was detected in all three states, SLEV activity was detected in Chihuahua and Michoacán, and MDV activity was detected in Chihuahua. None of the animals was seropositive for Cache Valley virus, the most common and widely distributed BUN serogroup virus in North America. In conclusion, we provide serologic evidence that select flaviviruses and BUN serogroup viruses infect vertebrate animals in Chihuahua, Guerrero, and Michoacán. We also provide the first evidence of LOKV and MDV activity in Mexico.

Lesiones de potencial maligno incierto (B3): nuestra experiencia en el Instituto Alexander Fleming / Lesions of uncertain malignant potential (B3): Our experience at the Alexander Fleming Institute

Objetivo: Revisar la correlación radiopatológica de las lesiones de potencial maligno incierto (B3) de nuestra institución, evaluar la conducta y establecer el porcentaje de subestimación en relación a las lesiones tratadas quirúrgicamente. Material y método: Estudio retrospectivo de la base de datos de procedimientos intervencionistas efectuados en el servicio de diagnóstico por imágenes del Instituto Alexander Fleming entre mayo de 2016 y diciembre de 2019 inclusive. Se incluyeron las pacientes con resultado histológico en la biopsia percutánea de uno o más de los siguientes diagnósticos: atipia epitelial plana (AEP), cicatriz radiada/lesión esclerosante compleja (CR), hiperplasia ductal atípica (HDA), neoplasia lobular clásica (NL), lesión papilar (LP) o tumor phyllodes (TP). Resultados: De 67 pacientes analizadas, el 43.3% se manifestaron en los estudios por imágenes con nódulos y en un 37.3% con microcalcificaciones agrupadas. La LP fue la lesión B3 más frecuente en un 44.8% seguido por la AEP en un 16.4%. El 98.5% de las pacientes presentó adecuada concordancia radiopatológica. Fueron sometidas a cirugía 48 pacientes, las 19 pacientes restantes continuaron con seguimiento clínico radiológico. La anatomía patológica de la pieza quirúrgica reflejó que en un 33.3% hubo subestimación en relación a la biopsia; en más de la mitad de los casos correspondieron a CDIS. Conclusiones: El porcentaje de subestimación con resultado final de CDIS o CDI de bajo grado se encontró dentro de los parámetros hallados en la literatura. Si bien logramos reducir la tasa de cirugías al 71% de pacientes con lesiones B3, una adecuada selección para efectuar exéresis con aguja por sistema de vacío podría reducir aún más el número de cirugías innecesarias y probablemente la tasa de subestimación.

Objective: To review the radiopathological correlation of lesions of uncertain malignant potential (B3) diagnosed in our institution, as well as to evaluate the therapeutic conduct and to establish the percentage of underestimation of the excised lesions. Material and method: This work consists of a retrospective study of the database which in- cludes the interventional procedures performed in the Imaging Department of the Alexander Fleming Institute between May 2016 and December 2019. Patients with a histological outcome in the percutaneous biopsy of one or more of the following diagnosis were included: flat epithelial atypia (FEA), radial scar (RS) /complex sclerosing lesion (CSL), atypical ductal hyperplasia (ADH), classic lobular neo- plasia (LN), papillary lesión (PL) or phyllodes tumor (PT). Results: Out of the 67 analyzed patients, 43.3% were perceived as nodules at imaging examinations and 37.3% as grouped microcalcifications. Papillary lesion was the most frequently diagnosed B3 lesion (44.8%), followed by flat epithelial atypia (16.4%). 98.5% of patients presented an accurate imaging-pathology concordance. 48 patients underwent surgery and the remaining 19 patients continued with clinical and radiological follow-up. The histopathology of the surgical specimen reflected that in 33.3% of the cases there was an underestimation in relation to the percutaneous biopsy; in over half of these cases they corresponded with DCIS. Conclusions: The percentage of underestimation with final diagnosis of DCIS or low grade IDC coincided with the parameters found in current literature. Even though we were able to reduce the surgical rate to 71% of patients with B3 lesions, a proper selection of cases which could be candidates for vacuum assisted excisional biopsy could further reduce the number of unnecessary surgeries and probably the un- derestimation rate as well.

A Real-Time PCR Assay for Detection of Low Pneumocystis jirovecii Levels.

Here we report a new real-time PCR assay using SYBR Green which provides higher sensitivity for the specific detection of low levels of Pneumocystis jirovecii. To do so, two primer sets were designed, targeting the family of genes that code for the most abundant surface protein of Pneumocystis spp., namely the major surface glycoproteins (Msg), and the mitochondrial large subunit rRNA (mtLSUrRNA) multicopy gene, simultaneously detecting two regions. PCR methods are instrumental in detecting these low levels; however, current nested-PCR methods are time-consuming and complex. To validate our new real-time Msg-A/mtLSUrRNA PCR protocol, we compared it with nested-PCR based on the detection of Pneumocystis mitochondrial large subunit rRNA (mtLSUrRNA), one of the main targets used to detect this pathogen. All samples identified as positive by the nested-PCR method were found positive using our new real-time PCR protocol, which also detected P. jirovecii in three nasal aspirate samples that were negative for both rounds of nested-PCR. Furthermore, we read both rounds of the nested-PCR results for comparison and found that some samples with no PCR amplification, or with a feeble band in the first round, correlated with higher Ct values in our real-time Msg-A/mtLSUrRNA PCR. This finding demonstrates the ability of this new single-round protocol to detect low Pneumocystis levels. This new assay provides a valuable alternative for P. jirovecii detection, as it is both rapid and sensitive.

Consensus Multilocus Sequence Typing Scheme for Pneumocystis jirovecii.

Pneumocystis jirovecii is an opportunistic human pathogenic fungus causing severe pneumonia mainly in immunocompromised hosts. Multilocus sequence typing (MLST) remains the gold standard for genotyping of this unculturable fungus. However, the lack of a consensus scheme impedes a global comparison, large scale population studies and the development of a global MLST database. To overcome this problem this study compared all genetic regions (19 loci) currently used in 31 different published Pneumocystis MLST schemes. The most diverse/commonly used eight loci, ß-TUB, CYB, DHPS, ITS1, ITS1/2, mt26S and SOD, were further assess for their ability to be successfully amplified and sequenced, and for their discriminatory power. The most successful loci were tested to identify genetically related and unrelated cases. A new consensus MLST scheme consisting of four genetically independent loci: ß-TUB, CYB, mt26S and SOD, is herein proposed for standardised P. jirovecii typing, successfully amplifying low and high fungal burden specimens, showing adequate discriminatory power, and correctly identifying suspected related and unrelated isolates. The new consensus MLST scheme, if accepted, will for the first time provide a powerful tool to investigate outbreak settings and undertake global epidemiological studies shedding light on the spread of this important human fungal pathogen.

Optimized DNA extraction and purification method for characterization of bacterial and fungal communities in lung tissue samples.

Human lungs harbor a scarce microbial community, requiring to develop methods to enhance the recovery of nucleic acids from bacteria and fungi, leading to a more efficient analysis of the lung tissue microbiota. Here we describe five extraction protocols including pre-treatment, bead-beating and/or Phenol:Chloroform:Isoamyl alcohol steps, applied to lung tissue samples from autopsied individuals. The resulting total DNA yield and quality, bacterial and fungal DNA amount and the microbial community structure were analyzed by qPCR and Illumina sequencing of bacterial 16S rRNA and fungal ITS genes. Bioinformatic modeling revealed that a large part of microbiome from lung tissue is composed of microbial contaminants, although our controls clustered separately from biological samples. After removal of contaminant sequences, the effects of extraction protocols on the microbiota were assessed. The major differences among samples could be attributed to inter-individual variations rather than DNA extraction protocols. However, inclusion of the bead-beater and Phenol:Chloroform:Isoamyl alcohol steps resulted in changes in the relative abundance of some bacterial/fungal taxa. Furthermore, inclusion of a pre-treatment step increased microbial DNA concentration but not diversity and it may contribute to eliminate DNA fragments from dead microorganisms in lung tissue samples, making the microbial profile closer to the actual one.

Breast Cancer in Young Women Presents With More Aggressive Pathologic Characteristics: Retrospective Analysis From an Argentine National Database.

PURPOSE: Multiple studies have reported that breast cancer in young patients is associated with aggressive characteristics, and it is suggested that prognosis is worse independently of pathologic variables. PATIENTS AND METHODS: We performed a retrospective analysis of the Breast Cancer Registry of the Argentinian Society of Mastology, including public and private centers. Patients ≤ 40 years of age at diagnosis were classified as "young," and patients ≤ 35 years of age at diagnosis were classified as "very young." Univariate and multivariate analyses were performed to detect differences between groups. RESULTS: Patients ≤ 40 years of age comprised 10.40% (739/7,105) of the participants, with an average age of 35.61 ± 4.04 years. Multivariate analysis showed that human epidermal growth factor receptor 2 (HER2)-positive tumor phenotype (odds ratio [OR], 1.82), nodal involvement (OR, 1.69), histologic grade (grade 3 OR, 1.41), and tumor size (T2 OR, 1.37; T3-T4, 1.47) were independently associated with younger age at diagnosis. Patients ≤ 35 years of age (n = 286), compared with patients 36 to 40 years of age, had a higher proportion of HER2 tumors (24.58% v 16.94%; P = .021), absence of progesterone receptor expression (29.85% v 22.95%; P = .043), and stage 3 cancer (29.34% v 18.52%; P < .001). Fewer breast-conserving surgeries (75.37% v 62.89%; P < .001) and more adjuvant chemotherapy (59.04% v 36.66%; P < 0.001) were reported in patients ≤ 40 years of age. CONCLUSION: In the population studied, breast cancer in young women was associated with aggressive pathologic features and locally advanced disease at the time of diagnosis. Moreover, tumor characteristics in very young patients with breast cancer nested in the population ≤ 40 years of age showed differences in important prognostic factors. More high-quality evidence is needed to improve treatment strategies in these patients.

Colonización por Pneumocystis jirovecii en mujeres gestantes y recién nacidos en Lima, Perú / neumocystis jirovecii colonisation in pregnant women and newborns in Lima, Peru

ANTECEDENTES: La primoinfección por Pneumocystis jirovecii ocurre de forma asintomática antes de los 6 meses de edad, lo que sugiere que la infección se adquiere muy precozmente en la vida. Se ha descrito también la presencia de neumonía por Pneumocystis en recién nacidos, lo que indica la necesidad de estudiar la colonización en el binomio madre-hijo. OBJETIVOS: Evaluar la prevalencia de colonización de Pneumocystis en gestantes y explorar la potencial transmisión transplacentaria. MÉTODOS: Estudio transversal que incluyó a mujeres gestantes mayores de 18 años con 37 o más semanas de gestación y negativas para el VIH que acudieron al Hospital Cayetano Heredia en los años 2016-2017. Se obtuvo información clínica y demográfica de la gestante y del recién nacido. Se tomaron muestras de lavado orofaríngeo/hisopado nasal de la gestante, de placenta y de aspirado nasofaríngeo/hisopado nasal del recién nacido. Todas las muestras respiratorias fueron analizadas mediante PCR anidada. En el caso de las muestras de placenta solo fueron analizadas aquellas procedentes de mujeres con resultados positivos de PCR para Pneumocystis en las muestras respiratorias. RESULTADOS: De las 92 gestantes incluidas en el estudio cinco presentaban colonización por Pneumocystis (5,43%). Se evaluaron las muestras de 87 recién nacidos y las placentas de las cinco madres con PCR positiva, no encontrándose ADN de Pneumocystis en ninguna de ellas. CONCLUSIONES: Aunque el 5,43% de las mujeres gestantes estuvieran colonizadas por Pneumocystis no pudo determinarse el rol de esta colonización en la transmisión a sus recién nacidos, ya que en ninguno de ellos se demostró la presencia de Pneumocystis

BACKGROUND: Pneumocystisjirovecii primary infection occurs asymptomatically before 6 months of age, suggesting that the infection is acquired very early in life. Furthermore, Pneumocystis pneumonia has been described in newborns, which emphasizes the importance of studying Pneumocystis colonization in mother-infant pairs. AIMS: To evaluate the prevalence of Pneumocystis colonization among pregnant women and to determine the potential transplacental transmission. METHODS: A cross-sectional study was carried out on HIV-negative women over 18 years-old, and 37 or more weeks of pregnancy attending Hospital Cayetano Heredia Maternity unit during 2016-2017. Clinical and demographical information was collected on them and their newborns. Oropharyngeal washes, nasal swabs, and placenta samples were collected from women, as well as a nasopharyngeal aspirate and nasal swab from newborns. All respiratory samples were analysed by nested-PCR for the detection of Pneumocystis. Placenta samples from women with a positive PCR result in their respiratory samples were also analysed by nested-PCR. RESULTS: Of the 92 pregnant women included, five of them (5.43%) were colonized by Pneumocystis. Pneumocystis DNA was not found in any of the 87 available newborn samples or in the placentas of the five women who had a positive result by PCR in their upper respiratory samples. CONCLUSIONS: It was found that 5.43% of the pregnant women were colonized by Pneumocystis, there was no evidence of any role of this colonization in the transmission to their newborns, since none of them tested positive for Pneumocystis