Netrin-1 Stimulates Migration of Neogenin Expressing Aggressive Melanoma Cells.

Netrin-1 is a neural guidance factor that regulates migration and positioning of neural crest-derived cells during embryonic development. Depending on the type of Netrin-1 receptor expression, cells are either attracted or repulsed by Netrin-1. Postnatal expression of Netrin-1 is detected in brain, colon, liver, and kidney, which are common sites of cancer metastasis, including melanoma. Thus, understanding the dynamics between Netrin-1 and its receptors could explain the attraction of melanoma towards these Netrin-1-expressing tissues. Here, we investigate whether the Netrin-1-attractive receptor Neogenin can affect migration of melanoma cells towards a Netrin-1 source. Results from Western blot (WB) analysis show higher expression of Neogenin in aggressive compared to non-aggressive melanoma cells. Cell migration experiments show increased migration of Neogenin-expressing aggressive melanoma cells towards exogenous, soluble recombinant human Netrin-1 and towards a Netrin-1-expressing cell line. Furthermore, WB reveals ERK1/2 activation and increased N-cadherin expression in Neogenin-expressing aggressive melanoma cells treated with rhNetrin-1. Moreover, treatment with anti-Neogenin blocking antibody caused decreased migration towards Netrin-1-expressing cells and reduced ERK1/2 activity in Neogenin-expressing aggressive melanoma cells. These results suggest Neogenin may play a role during migration of melanoma cells towards Netrin-1 via ERK1/2 signaling.

Assessment of UL56 Mutations before Letermovir Therapy in Refractory Cytomegalovirus Transplant Recipients.

De novo mutations in the UL56 terminase subunit and its associated phenotypes were studied in the context of cytomegalovirus (CMV) transplant recipients clinically resistant to DNA-polymerase inhibitors, naive to letermovir. R246C was the only UL56 variant detected by standard and deep sequencing, located within the letermovir-resistance-associated region (residues 230-370). R246C emerged in 2/80 transplant recipients (1 hematopoietic and 1 heart) since first cytomegalovirus replication and responded transiently to various alternative antiviral treatments in vivo. Recombinant phenotyping showed R246C conferred an advanced viral fitness and was sensitive to ganciclovir, cidofovir, foscarnet, maribavir, and letermovir. These results demonstrate a low rate (2.5%) of natural occurring polymorphisms within the letermovir-resistant-associated region before its administration. Identification of high replicative capacity variants in patients not responding to treatment or experiencing relapses could be helpful to guide further therapy and dosing of antiviral molecules. IMPORTANCE We provide comprehensive data on the clinical correlates of both CMV genotypic follow-up by standard and deep sequencing and the clinical outcomes, as well as recombinant phenotypic results of this novel mutation. Our study emphasizes that the clinical follow-up in combination with genotypic and phenotypic studies is essential for the assessment and optimization of patients experiencing HCMV relapses or not responding to antiviral therapy. This information may be important for other researchers and clinicians working in the field to improve the care of transplant patients since drug-resistant CMV infections are an important emerging problem even with the new antiviral development.

Impact of Inflammatory Response Modifiers on the Incidence of Hospital-Acquired Infections in Patients with COVID-19.

INTRODUCTION: The study aim was to assess the influence of inflammatory response modifiers, including anti-interleukin-6 (IL-6) biologics and corticosteroids, on the incidence of hospital-acquired infections in patients with coronavirus disease 2019 (COVID-19). METHODS: Case-control study performed at a university hospital from February 26 to May 26, 2020. Cases were defined as patients with COVID-19 who developed hospital-acquired infections. For each case, two controls were selected among patients without infections. Cases and controls were matched obeying three criteria in a hierarchical sequence: length of hospital stay up until the first infection; comorbidity; and need for Intensive care unit (ICU) admission. Conditional logistic regression analysis was used to estimate the association of exposures with being a case. RESULTS: A total of 71 cases and 142 controls were included. Independent predictors for acquiring a hospital infection were chronic liver disease [odds ratio (OR) 16.56, 95% CI 1.87-146.5, p = 0.012], morbid obesity (OR 6.11, 95% CI 1.06-35.4, p = 0.043), current or past smoking (OR 4.15, 95% CI 1.45-11.88, p = 0.008), exposure to hydroxychloroquine (OR 0.2, 95% CI 0.041-1, p = 0.053), and invasive mechanical ventilation (OR 61.5, 95% CI 11.08-341, p ≤ 0.0001). CONCLUSIONS: Inflammatory response modifiers had no influence on acquisition of nosocomial infections in admitted patients with COVID-19. Hospital-acquired infections primarily occurred in the critically ill and invasive mechanical ventilation was the main exposure conferring risk.

Short-Term Peripheral Venous Catheter-Related Bloodstream Infections: Evidence for Increasing Prevalence of Gram-Negative Microorganisms from a 25-Year Prospective Observational Study.

The aim of this study was to describe the etiology and outcome of short-term peripheral venous catheter (PVC)-related bloodstream infections (PVCRBSI) in a 25-year period (1992 to 2016) and to identify predictive factors of Gram-negative PVCRBSI. This was a prospective observational study including all episodes of PVCRBSI. A multivariate logistic regression model adjusted for calendar year was built to explore factors associated with a Gram-negative bacterial etiology. Over the study period, 711 episodes of PVCRBSI were identified. Incidence rate of PVCRBSI increased from 0.06 to 0.13 episodes/1,000 patient-days. A Gram-negative bacterial etiology was demonstrated in 162 (22.8%) episodes. There was a significant increase in the proportion of Gram-negative infections (22.6% in 1992 to 1996 versus 33.2% in 2012 to 2016). Independent predictive factors of Gram-negative PVCRBSI were the following: being in the hospital for more than 7 days with a catheter in situ for more than 3 days (adjusted odds ratio [aOR], 1.80; 95% confidence interval [CI], 1.20 to 2.69), surgery in the previous month (aOR, 2.39; 95% CI, 1.40 to 4.09), and antimicrobial treatment with beta-lactams (aOR, 1.80; 95% CI, 1.16 to 2.78). In conclusion, we reported an increase in the prevalence of Gram-negative PVCRBSI over the last 25 years. Factors associated with a Gram-negative bacterial etiology were being in the hospital for more than 7 days with a catheter in situ for more than 3 days, having undergone surgery, and having received antimicrobial treatment with beta-lactams.

Acute pulmonary involvement by paracoccidiodomycosis disease immediately after kidney transplantation: Case report and literature review.

Paracoccidioides brasiliensis is the cause of paracoccidioidomycosis, one of the most important systemic mycoses in Latin America. Human disease has been observed in a limited geographic and ecological niche, and it is attributed to exposure to the fungus in soil. Most primary infections are subclinical, as the infection is contained by the host mainly through cell-mediated immune response. However, as the fungus has the ability to survive in a dormant state for long periods, an impairment of the immune response may lead to reactivation and clinical disease. Surprisingly, paracoccidioidomycosis has rarely been reported in transplanted patients. The aim of this communication is to report a case occurring in a kidney recipient in an acute clinical form immediately after transplantation, and to review the available information on previously reported cases.

Papillary cystoadenoma lymphomatosum (Warthin-like) of minor salivary glands.

Papillary cystadenoma lymphomatosum is a benign salivary gland tumor most frequently located in the parotid gland (Warthin's tumor). Its presentation in other major, or in minor, salivary glands is rare. Clinically, it manifests as a slow growing tumor, fluctuant on palpation due to its cystic morphology. The treatment of choice is complete excision with wide tumor-free margins. We present a 73-year-old female patient with an asymptomatic tumor of 8 years evolution in the right posterior area of the hard palate. We performed surgical excision and a biopsy, which was reported as papillary cystadenoma lymphomatosum. During the post-operative examination carried out after 3 weeks, it was observed that the lesion had recurred. The lesion was re-operated, performing the excision with CO2 laser and including the periosteum to ensure complete resection of the tumor. At 10 months follow-up, there was no recurrence of the lesion. This article includes a review of this condition and discusses its most important clinical and pathologic features and therapeutic approaches.

[Human immunodeficiency virus-infected patients with community-acquired pneumonia: implication of respiratory viruses]. / Implicación de los virus respiratorios en la neumonía adquirida en la comunidad en pacientes infectados por el virus de la inmunodeficiencia humana.

The role of respiratory viruses in community-acquired pneumonia (CAP) in human immunodeficiency virus (HIV)-infected patients has not been extensively investigated. The objective was to study the implication of respiratory viruses in HIV patients with CAP, through a prospective, three-year study in a third-level hospital. Respiratory viruses were implicated in 14 of the 67 cases of CAP diagnosed and were the only microorganism isolated in 8 of them. Evolution of the disease was similar in patients with CAP associated with respiratory virus infection and those with CAP alone. Respiratory virus infection in HIV-infected patients with CAP is not associated with a poorer prognosis.

Reactividad vascular en anillos aórticos de rata: estudio comparativo en dos modelos de diabetes experimental / Vascular reactivity in aortic rings of rats: comparative study in two models of experimental diabetes

Los modelos experimentales para la diabetes de tipo I incluyen sustancias químicas (estreptozotocina o aloxano) y procedimientos quirúrgicos como la pancreatectomía. En estudios previos efectuados en anillos aórticos obtenidos de ratas diabéticas por estreptozotocina o pancratectomía, se ha observado una alteración en la respuesta vascular.

In vitro effect of melatonin on oxygen consumption in liver mitochondria of rats.

OBJECTIVE: To examine the in vitro effect of melatonin on rat mitochondrial liver respiration. METHODS: Oxygen consumption by liver mitochondria was measured polarographically in the presence of one of the following Krebs' cycle substrates: Lsuccinate, DL-3- beta-hydroxybutyrate or L-malate. Respiratory velocities at rest (state 4) and during rapid respiration in the presence of substrate and adenosine diphosphate (state 3) were measured in the presence of 10 (-9)-10(-3) M concentrations of melatonin. RESULTS: In vitro melatonin (10(-7)-10(-3) M) reduced state 3 mitochondrial respiration. Basal, state 4 respiration was not affected by melatonin. Consequently, control respiratory index (i.e., the ratio of state 3 to state 4 respiration) was inhibited by melatonin with a threshold at 10(-7) M concentration. CONCLUSION: The ability of melatonin to curtail acutely the stimulation of oxygen consumption in liver mitochondria may protect the mitochondria from excessive oxidative damage.

Activación cardiocirculatoria en ratas anestesiadas con Ketamina: efectos de la premedicación con Diazepam / Cardiostimulatory activation in rats anesthetized with Ketamine: effects of premedication with Diazepam

La anestesia con ketamina (A-Kt) provoca un aumento de la presión arterial (PA) y de la frecuencia cardíaca (FC), por activación del sistema nervioso simpático. En este estudio se evalúo el efecto de la medicación con diazepam (DZ), flumazenil (FZ), picrotoxina (PTX), y PK11195, sobre la respuesta cardiovascular observada durante la A-Kt. Se emplearon ratas Wistar machos, divididas en 9 grupos (n=10): I- A-Kt; II- A-Kt y DZ; III- A-Kt e inyectado con FZ; IV- A-Kt, inyectado con FZ y DZ; V- A-Kt e inyectado con PTX, VI- A-Kt, inyectado con PTX y DZ; VII- A-Kt e inyectado con PK11195; VIII- A-Kt, DZ e inyectado con PK11195; IX- Controles despiertos. La A-Kt provocó en las ratas de los grupos I y IV un aumento de la PA y FC (P<0,01) y en el grupo VII (P<0,01); (IV-VII vs I P>0,05). En los animales del grupo II no se registró respuesta presora (P>0.05), pero aumentó la FC 45 min después de la inyección de Kt (P<0,05). En los grupos V y VI se incrementó la PA (P<0.01; V vs VI P>0,05), y la FC (P<0,01) respectivamente. La inyección de PK11195 no antagonizó la acción del DZ (grupo VIII) en los animales A-Kt. La ausencia de variaciones significativas en la PA en el grupo II, asociado al aumento observado en los grupos I, III, IV, V, VI, VII y VIII sugieren que receptores GABA A modularían la estimulación simpática cardiovascular evocada por la Kt. Posiblemente, tanto los efectos de diazepam como los de la Kt involucrarían a estructuras tromboencefálicas que intervienen en los mecanismos de regulación central de la actividad cardiocirculatoria.

Efecto de la anestesia general endovenosa con Ketamina o Propofol sobre la glucemia de la rata / Blood sugar concentrations during ketamine or propofol anaesthesia in rats with or without Ó and ß adrenergic blockade

La glucemia se encuentra controlada por complejos mecanismos neuroendócrinos, que pueden alterarse en situaciones de estrés. La finalidad del presente trabajo fue estudiar los efectos de la anestesia con ketamina (kt) y propofol (pf) sobre los niveles glucémicos de la rata. La glucemia se determinó en ratas despiertas y anestesiadas: 1) durante una prueba de tolerancia endovenosa a la glucosa (PTEG) y 2) bloqueadas con fentolamina/propranolol durante la realización de una PTEG. La anestesia se realizó con kt (Dosis de inducción: 40 mg . kg-1; dosis de infusión: 1 mg . kg-1 . min-1) o pf (Dosis de inducción: 15 mg . kg-1; dosis de infusión: 0.8 mg . kg-1 . min-1), 30 min antes del comienzo de la PTEG. El propanolol y la fentolamina se administraron luego, a una dosis de: 2 mg . kg-1 ip, y 0.015 mg . min-1 endovenosa continua. Durante la PTEG, las ratas anestesiadas mostraron una respuesta hiperglucémica moderada a la sobrecarga de glucosa (Kt: P < 0.01 entre los 5-10 min; P < 0.05 a los 20 min; Pf: p < 0.05 entre los 5-20 min). La mayor respuesta hiperglucemiante con kt fue abolida por el bloqueo adrenérgico (P < 0.01 entre los 5-10 min). lo que no ocurrió con pf (P > 0.05 entre los 5-10 min). Estos resultados sugieren la existencia de un tono inhibitorio de la secreción de insulina (efecto glucogenolítico) en las ratas anestesiadas con kt, de naturaleza adrenérgica, que no se observa en los animales anestesiados con pf. Por lo expuesto, la acción hiperglucemiante hallada debería ser tenida en cuenta al utilizar la kt, y en menor grado al pf, como inductor anestésico endovenoso en pacientes añosos o diabéticos (sometidos a situaciones agudas de estrés) en donde la descompensación metabólica es mucho más frecuente.

Blood sugar concentrations during ketamine or pentobarbitone anesthesia in rats with or without alpha and beta adrenergic blockade

Plasma glucose concentrations were measured in: 1) conscious and anesthetized rats during an iv glucose tolerance test (IVGTT) and 2) conscious and anaesthetized phentolamine/propranolo] blocked rats during an IVGTT. Anesthesia was induced with ketamine (120 mg . kg-1) or pentobarbitone (60 mg - kg-1) ip at -30 min of the beginning of the IVGTT, which was followed by 2 injections of the anesthetic agents at intervals of 30 min. Propranolol (2 mg . kg-1) was given ip at -25 and -5 min. An iv infusion of phentolamine (0.015 mg . min-1) was started at -20 min and continued up to the end of the experiment. During the IVGTT, the anesthetized rats showed a moderate hyperglycemic response to glucose load compared to conscious animals (ketamine: p < 0.01 at 5 min; and p < 0.05 at 10-20 min; pentobarbitone: p < 0.05 at 5-20 min). The hyperglycemic response to glucose administration in the conscious rats was not affected by adrenergic blockade (p > 0.05). While in ketamine anesthetized rats the increased glucose response was abolished by adrenergic blockade (p < 0.05 at 5-10 min), this effect was not seen in pentobarbitone anesthetized animals. These results suggest the existence of an inhibitory tone on insulin secretion and a glycogenolytic response in ketamine anesthetized rats, probably mediated by adrenergic inervation of the pancreas and liver and by circulating catecholamines secreted from the adrenal medulla.

Cirugía ambulatoria en patalogía de paredes abdominales / Ambulatory surgery in abdominal walls pathology

Durante el último año se operaron 117 casos con variada patología parieto abdominal en forma ambulatoria. No utilizamos medicación preoperatoria, salvo una dosis profiláctica de antibióticos. Se implementaron aquellas técnicas que permitieron un cierre elástico-resistente de los defectos, incorporando a los pacientes inmediatamente a sus tareas habituales, con marcada disminución de la morbilidad postoperatoria. Las principales ventajas de este proceder son para el paciente y para quien deba solventar los gastos que todo hecho quirúrgico implica

Efectos endócrinos de la hipnosis con tiopental sódico en los perros / Endocrine effects of thiopental anaesthesia in dogs

se estudiaron los efectos endócrinos de la hipnosis con tiopental sódico (TPS) en perros con respiración espontánea (RE) y controlada mecánicamente (RC) durante tres horas. Se emplearon 18 perros divididos en tres grupos: 1-controles no anestesiados (CNA). 2-anestesiados con TPS y RE y 3-anestesiados con TPC y RC. Se controló la: tensión arterial media, frecuencia cardíaca, frecuencia respiratoria y temperatura rectal. Se efectuaron extracciones de sangre antes de la inducción y luego periódicamente para controlar la glucemia y los niveles de: ácidos grasos no esterificados ACTH, cortisol, catecolaminas, insulina, T3, T4 junto con las concentraciones plasmáticas de TPS. También se monitoreó el pH, gases en sangre, exceso de base y bicarbonato standard. La técnica anestésica descrita con RE y RC no modificó los niveles séricos y plasmáticos de insulina, T3 y catecolaminas, pero provocó una disminución importante en los ácidos grasos no esterificados séricos y en las concentraciones de T4, sin embargo, no logró suprimir totalmente la respuesta tardía del eje hipófiso-suprarrenal al stress anestésico.

Efectos del bloqueo ß-adrenergico con propranolol sobre los mecanismos de regulación de la glucemia en el perro / Effects of ßeta-adrenergic blocking with propranolol about mechanisms of glucose regulation in the dog

Conociendo que el bloqueo ß-adrenérgico con propranolol (P) puede provocar cuadros hipoglucémicos en pacientes diabéticos insulino-dependientes, hemos analizado la respuesta de algunas variables hormonales (insulina (I) y cortisol (C) séricos, adrenalina (A) y noradrenalina (NA) plasmáticas) y metabólicas (glucemia y ácidos grasos libres (AGL) séricos) a la administración de esta droga a perros machos por la vía oral (dosis: 80 mg, 3 veces por día, durante 10 días) (grupo A) o endovenosa (dosis: 1 mg/Kg a -30 min) (grupo B), estudiándose en estos últimos, el comportamiento de dichas variables durante la hipoglucemia insulinica (HI). Se controló la frecuencia cardíaca como índice del bloqueo. Se obtuvieron muestras de sangre en condiciones basales en los perros del grupo A, a 0 y 30 min., y en los del grupo B a -30 y o min., continuandose durante la HI cada 30 min. por 2 horas. En los animales con bloqueo crónico, el P no afectó los niveles de glucemia, I sérica y catecolaminas plasmáticas, pero redujo los de AGL y C séricos cuando se los comparó con los respectivos controles. Durante la HI (grupo B), el tratamiento con P no afectó el comportamiento de la glucemia o de la insulinemia, observándose descensos en los niveles de AGL (p < 0,001) y C (p < 0,05) séricos junto con un aumento de la repsuesta adrenalínica a la hipoglucemia, al compararlos con los de los perros no bloqueados. Los resultados expuestos indican que el mecanismo ß-adrenérgico no desempeña un papel importante en la recuperación de la HI