Generic high-capacity protein capture and release by pH control.

Techniques for immobilization and release of proteins are of general interest but challenging to develop. Here we show a new method for high-capacity (several µg cm-2) immobilization of proteins in polyelectrolyte brushes by multivalent hydrogen bonds. Upon increasing pH, the proteins are fully released with preserved structure and activity.

Little red riding hood in the social forest. Online grooming as a public health issue: a narrative review.

INTRODUCTION: Online grooming is a manipulative process through which an adult attempts to arrange a sexual interaction with a minor using internet. Children are constantly exposed to the online world, posing online grooming as a public health issue. OBJECTIVES: The aim of this narrative review is to describe the state of online grooming preventive strategies in recent literature through an overview of online grooming phenomenon. METHODS: Our literature review included research articles and reviews published between January 2014 and March 2019, as well as reference lists of included studies. RESULTS: The analysis provides a picture of online grooming phenomenon, identify recurrent features of perpetrators and victims. Several preventive strategies have been implemented, but they lack any kind of efficacy evaluation and miss a theory driven approach. Fragmentation of preventive initiatives is a critical issue, in contrast with the need of an institutional public health strategy. CONCLUSIONS: While the attention around online grooming is growing, there is still the need of further sensitizing the involved stakeholders and developing evidence based preventive strategies under an institutional guidance.

Paraxial optical fields whose intensity pattern skeletons are stable caustics.

We construct exact solutions to the paraxial wave equation in free space characterized by stable caustics. First, we show that any solution of the paraxial wave equation can be written as the superposition of plane waves determined by both the Hamilton-Jacobi and Laplace equations in free space. Then using the five elementary stable catastrophes, we construct solutions of the Hamilton-Jacobi and Laplace equations, and the corresponding exact solutions of the paraxial wave equation. Therefore, the evolution of the intensity patterns is governed by the paraxial wave equation and that of the corresponding caustic by the Hamilton-Jacobi equation.

LGBTIQ, pensar la diversidad / LGBTIQ, Thinking About Diversity

Con el objetivo de analizar la percepción acerca del colectivo LGBTIQ por parte del personal de salud, administrativos y usuarios del siste-ma de salud en CeMAP CABA (Ciudad Autónoma de Buenos Aires) OsPeCon, así como identificar la discriminación, sus causas y consecuencias, se realizó un estudio cualitativo, de caso, etnográfico.Se realizaron cinco grupos focales y se analizó la información siguiendo los pasos de la teoría fundamentada. En los grupos focales surgieron dudas acerca de la definición de orientación sexual y las siglas I-Q. Se reconocieron prejuicios relacionados al VIH/SIDA, ETS y adicciones como base de la discriminación y la estigmatización. Se evidenció la persistencia de creencias populares como origen de la orientación sexual. Se vio reflejada la heteronormatividad como característica social y la diferencia generacional como postura negativa. Se identificó como forma de discriminación a la violencia verbal y el rechazo al contacto, teniendo como consecuencia depresión, consumo de sustancias y suicidio. Las cuestiones de géneros son temas en continua evolución en la sociedad, por lo que creemos importante estar informados, con una visión empática y de respeto para brindar una atención adecuada a las personas LGBTIQ, teniendo un rol que nos permite deconstruir los estereotipos (AU)

This qualitative ethnographic case study analyzes perceptions of the LGBTIQ community held biomedical professionals, administrative staff and patients in the Health center of OSPeCon, CABA.The purpose of this analysis is to identify discrimination, its causes and consequencesFive focus groups were carried out and the information was analyzed according to the grounded theory.Major themes that emerged from focus groups included confusion regarding the definition of sexual orientation and the acronym I-Q Beliefs related to HIV/AIDS, STD and addiction were noted to be the foundation for discrimination and stigmatization. Other beliefs identified included heteronormativity, which was more prevalent in older generations. The use of popular beliefs to explain the origin of sexual orientation was often justification for discrimination Means of discrimination included verbal violence and rejecting personal contact. Consequences of discrimination identified included depression, substance abuse and suicide. Gender issues continue to evolve and we hope to analyze our own beliefs, deconstruct stereotypes, and educate ourselves in the development of an empathic and respectful attitude to this vulnerable population (AU)

EGFR is dispensable for c-Met-mediated proliferation and survival activities in mouse adult liver oval cells.

Liver progenitor cells rise as potential critical players in hepatic regeneration but also carcinogenesis. It is therefore mandatory to define the signals controlling their activation and expansion. Recently, by using a novel in vitro model of oval cell lines expressing a mutant tyrosine kinase-inactive form of c-Met we demonstrated that autocrine c-Met signalling plays an essential role in promoting oval cell survival. Here, we investigated the significance of the epidermal growth factor receptor (EGFR) signalling in oval cell proliferation and survival, as well as a potential functional crosstalk between the c-Met and the EGFR pathways. We found an autocrine activation of the EGFR-triggered pathway in Met(flx/flx) and Met(-/-) oval cells as judged by constitutive expression of the EGFR ligands, transforming growth factor-alpha (TGF-α) and heparin-binding EGF like growth factor (HB-EGF), and activation of EGFR. On the other hand, treatment with AG1478, a specific inhibitor of EGFR, effectively blocked endogenous and EGF-induced proliferation, while increased serum withdrawal and transforming growth factor-beta (TGF-ß)-induced apoptosis. These results suggest that constitutively activated EGFR might promote oval cell proliferation and survival. We found that hepatocyte growth factor (HGF) does not transactivate EGFR nor EGF transactivates c-Met. Furthermore, treatment with AG1478 or EGFR gene silencing did not interfere with HGF-mediated activation of target signals, such as protein kinase B (AKT/PKB), and extracellular signal-regulated kinases 1/2 (ERK 1/2), nor did it have any effect on HGF-induced proliferative and antiapoptotic activities in Met(flx/flx) cells, showing that HGF does not require EGFR activation to mediate such responses. EGF induced proliferation and survival equally in Met(flx/flx) and Met(-/-) oval cells, proving that EGFR signalling does not depend on c-Met tyrosine kinase activity. Together, our results provide strong evidence that in normal, untransformed oval cells, c-Met and EGFR represent critical molecular players to control proliferation and survival that function independent of one another.

Effectiveness of argon plasma coagulation in the treatment of chronic actinic proc.

INTRODUCTION: There are two kinds of actinic proctitis--one is acute and self-limited, and lasts about 3 months; the other is chronic and develops months to years after radiation therapy. The incidence of chronic actinic proctitis is about 5-20% of radiated prostate tumors. OBJECTIVE: To evaluate the effectiveness of argon plasma coagulation in the treatment of chronic actinic proctitis. MATERIAL AND METHOD: A retrospective search of patients with the diagnosis of actinic proctitis. The number of argon plasma coagulation therapies needed to achieve the symptom resolution was analyzed. RESULTS: We found 22 patients with a diagnosis of actinic proctitis. Nineteen were males (86.7%) and three (13.6%) were females. Nineteen patients (86.4%) had a diagnosis of prostate adenocarcinoma, one had a diagnosis of squamous-cell cervix carcinoma (4.5%), and two had a diagnosis of endometrial carcinoma (9.1%). The mean number of coagulation sessions needed for symptom resolution was 2.58 (absolute range 1-7) with a median of 2 sessions. CONCLUSION: Multiple treatments are described in the literature. None of them have shown promising results. Our results suggest that argon plasma coagulation is effective in the treatment of this condition, and achieves a rapid and sustained response with few sessions and a good safety profile.

Efectividad de la fulguración con argón plasma en el tratamiento de la proctitis actínica crónica / Effectiveness of argon plasma coagulation in the treatment of chronic actinic proctitis

Introducción: existen 2 tipos de proctitis actínica, una aguda autolimitada, que dura aproximadamente 3 meses y otra crónica que aparece a los meses o años de la radioterapia. La incidencia de proctitis actínica crónica es del 5-20% de los tumores prostáticos irradiados. Objetivo: evaluar la efectividad de la fulguración con argón plasma en el tratamiento de este tipo de proctitis. Material y método: estudio retrospectivo. Realizamos una búsqueda retrospectiva de aquellos pacientes diagnosticados de proctitis actínica entre 2004 y 2007. Analizamos el número de sesiones de fulguración con plasma de argón que fueron necesarias para la resolución de la sintomatología. Resultados: hemos hallado 22 pacientes con el diagnóstico de proctitis actínica. Diecinueve de los pacientes eran varones (86,4%) y tres mujeres (13,6%). De todos los pacientes 19 fueron diagnosticados de adenocarcinoma prostático (86,4%), una fue diagnosticada de carcinoma epidermoide de cérvix uterino (4,5%) y dos fueron diagnosticadas de adenocarcinoma de endometrio (9,1%). La media de sesiones de fulguración con plasma de argón necesarias para resolución de la clínica presentada fue de 2,58 (rango entre 1 y 7 sesiones) y con un mediana de 2 sesiones. Conclusión: en la literatura hay descritos múltiples tratamientos para la proctitis actínica. No obstante, ninguno de ellos ha presentado resultados demasiado prometedores. Nuestros resultados sugieren que la fulguración con plasma de argón es efectiva en el tratamiento de esta patología, consiguiendo una resolución rápida y mantenida de la sintomatología con pocas sesiones, además de presentar un buen perfil de seguridad(AU)

Introduction: there are two kinds of actinic proctitis - one is acute and self-limited, and lasts about 3 months; the other is chronic and develops months to years after radiation therapy. The incidence of chronic actinic proctitis is about 5-20% of radiated prostate tumors. Objective: to evaluate the effectiveness of argon plasma coagulation in the treatment of chronic actinic proctitis. Material and method: a retrospective search of patients with the diagnosis of actinic proctitis. The number of argon plasma coagulation therapies needed to achieve the symptom resolution was analyzed. Results: we found 22 patients with a diagnosis of actinic proctitis. Nineteen were males (86.7%) and three (13.6%) were females. Nineteen patients (86.4%) had a diagnosis of prostate adenocarcinoma, one had a diagnosis of squamous-cell cervix carcinoma (4.5%), and two had a diagnosis of endometrial carcinoma (9.1%). The mean number of coagulation sessions needed for symptom resolution was 2.58 (absolute range 1-7) with a median of 2 sessions. Conclusion: multiple treatments are described in the literature. None of them have shown promising results. Our results suggest that argon plasma coagulation is effective in the treatment of this condition, and achieves a rapid and sustained response with few sessions and a good safety profile(AU)

[Intravenous 3-day Helicobacter pylori eradication therapy is highly effective in patients with bleeding peptic ulcer]. / Alta eficacia erradicadora de la infección por Helicobacter pylori de una pauta terapéutica intravenosa de 3 días de duración en pacientes con úlcera péptica sangrante.

AIMS: To evaluate the efficacy of 3-day intravenous Helicobacter pylori eradication therapy in patients with bleeding peptic ulcer associated with H. pylori infection. MATERIAL AND METHOD: We studied 53 patients admitted to hospital with bleeding of the upper gastrointestinal tract due to peptic ulcer and positive urease test over a 12-month period. After endoscopic diagnosis, intravenous pantoprazole (40 mg/12 hours), metronidazole (500 mg/8 hours) and amoxicillin-clavulanic acid (1,000 mg/200 mg/8 hours) was administered for 72 hours. The efficacy of eradication therapy was evaluated by 13C-urea breath test at least 2 months after the end of treatment. RESULTS: Fifty-one patients were included. Of these, 40 had duodenal ulcer and 11 had gastric ulcer. H. pylori eradication was achieved in 87.5% of those with duodenal ulcers and in 63.6% of those with gastric ulcers (p = 0.066). No adverse reactions or episodes of bleeding recurrence were found and none of the patients withdrew from treatment. CONCLUSIONS: The ultra-short course eradication therapy used in this study is highly effective. Its efficacy is similar to that of oral treatment and it avoids certain problems such as adverse effects and adherence to treatment.

Total reflection of light propagating from an isotropic medium to an anisotropic medium.

We study the propagation of light from an isotropic medium to an anisotropic medium. It is shown that total reflection can occur only for propagation from a denser medium to a rarer medium; this result does not agree with that of Lin and Wu [Opt. Lett. 23, 22 (1998)].

Prevalence of hepatitis A virus antibodies in patients with chronic liver diseases.

OBJECTIVE: The age of persons with hepatitis A virus (HAV) infection in the general population has risen; these persons are at increased risk of clinically severe disease, especially patients with chronic liver disease. The aim of the present study was to analyze the prevalence of total antibodies against HAV in patients with chronic liver disease. METHODS: In a prospective study carried out between September 1998 and June 1999, 180 patients seen in the chronic liver disease outpatient department were studied. The prevalence of total anti-HAV antibodies was determined by age group, etiology and degree of histological damage, and according to the antecedents of risk for parenteral infection. A nonconditional logistic regression model was fitted with anti-HAV positivity as the dependent variable. RESULTS: Mean age was 44.1 years, with an anti-HAV prevalence of 77.2% (varying from 42.9% in the 21-25-year-old group to more than 83% in patients > 56-years old). Differences across groups regarding other categories (histological damage, etiology and history of parenteral or drug use) were not statistically significant, but the probability of anti-HAV positivity increased with age and a history of drug addiction. CONCLUSIONS: The prevalence of total anti-HAV antibodies is high among patients with chronic liver disease. We therefore recommend this test before vaccination against HAV, until current recommendations on universal childhood vaccination are implemented, in order to prevent hepatitis A epidemics in the general population.

Prevalencia de anticuerpos antivirus de la hepatitis A en pacientes con hepatopatías crónicas / Prevalence of hepatitis A virus antibodies in patients with chronic liver diseases

OBJETIVO: la edad de infección por el virus de la hepatitis A (VHA) ha aumentado en la población, con un mayor riesgo de gravedad clínica, sobre todo en pacientes con hepatopatía crónica. Se pretende conocer la prevalencia de anticuerpos totales frente al VHA en pacientes con hepatopatía crónica. PACIENTES Y MÉTODOS: se estudió de forma prospectiva a 180 pacientes atendidos consecutivamente en nuestra consulta de Hepatopatías Crónicas desde septiembre de 1998 hasta junio de 1999. Se determinó la prevalencia de anticuerpos totales anti-VHA por grupos de edad, etiologías, grado de afectación histológica y antecedentes de riesgo de infección por vía parenteral. Finalmente se ajustó un modelo de regresión logística no condicional con variable dependiente la presencia de anti-VHA. RESULTADOS: la edad media fue de 44,1 años, con una prevalencia de anti-VHA del 77,2 por ciento (desde el 42,9 por ciento entre 21-25 años hasta más del 83 por ciento a partir de 56 años). No existieron diferencias estadísticamente significativas según la afectación histológica, etiología o antecedentes de riesgo parenteral o de drogadicción, pero la probabilidad de tener anti-VHA aumentaba con la edad y con el antecedente UDVP. CONCLUSIONES: los pacientes con hepatopatía crónica presentan una alta prevalencia de anticuerpos totales anti-VHA, En consecuencia, en estos pacientes recomendamos su determinación previamente a la vacunación frente al VHA hasta que se introduzcan las recomendaciones actuales de vacunación generalizada de la población infantil para evitar epidemias de hepatitis A en la población general (AU)

Portal vein thrombosis associated to prothrombin G20210A mutation and protein C deficiency.

We describe a patient with left branch portal vein thrombosis involving two thrombophilic alterations, the prothrombin G20210A mutation and protein C deficiency. In spite of not being under anticoagulant treatment, the thrombus in the portal vein underwent complete and spontaneous lysis. No other risk factors were detected and no family history related to thrombosis was found.

[Percutaneous intrahepatic portosystemic shunt: its effects on hypersplenism]. / Derivación percutánea portosistémica intrahepática: efectos sobre el hiperesplenismo.

The aim of this study was to verify the early effects that the transjugular intrahepatic portosystemic shunt (TIPS) produces on thrombocytopenia and its possible relationship to portal pressure and the size of the spleen. A TIPS was placed in 24 cirrhotic patients (11 women and 13 men) with a mean age of 57.6 +/- 12.3 years. Prior to the test the platelets count, the size of the spleen and the portocaval gradient were determined. The same parameters were evaluated one day and one month afterwards. A significant increase was observed in then number of platelets following the placement of the prosthesis (87.6 +/- 55.2 vs 97 +/- 66.8 x 10(9)/l) (p < 0.05) which was maintained in the monthly control without achieving statistical significance (99.5 +/- 60.8 x 10(9)/l). A significant decrease was also observed in the size of the spleen from 156.7 +/- 28.7 mm during the previous control to 144.5 +/- 19.9 mm in the monthly control (p < 0.05). The portocaval gradient was significantly reduced following the procedure with the values being 23.25 +/- 3.86 mmHg prior to the TIPS, 10.29 +/- 3.84 mmHg in the immediate control and 10.37 +/- 4.81 mmHg at the one month control. A statistically significant correlation was observed between the size of the spleen and the number of platelets in both the previous control (r = 0.7264; p < 0.001) and in the monthly control (r = 0.5764; p < 0.05), between the size of the spleen and the portocaval gradient prior to the test (r = 0.5285; p < 0.05) and at one month (r = 0.7185; p < 0.01) and between the portocaval gradient and the number of platelets before the prosthesis (r = 0.5060; p < 0.05). TIPS may improve the thrombocytopenia in correlation with the decrease in portal pressure.

Complicated migraine: case report.

The occurrence of long lasting focal neurological deficit as a complication of migraine is well known. A high incidence of C.T. scan abnormalities have been seen in subjects affected by severe complicated migraine; in some cases such lesions had the aspect of cerebral infarction. In this report we will relate case of a 29 year old woman with complicated migraine and multifocal suffering within the area of the hind brain circulation. The hypodense area we found with C.T. in the left cerebellar hemisphere and the reversibility of this lesion could support the hypothesis of focal edema in our case.