[Challenges to the continuity of care of people living with HIV throughout the COVID-19 crisis in Peru]. / Los desafíos en la continuidad de atención de personas viviendo con VIH en el Perú durante la pandemia de la COVID-19.

The COVID-19 pandemic and societal response implemented may interact with the ongoing HIV epidemic in multiple ways. There are approximately 87000 people living with HIV (PLWH) who are at risk of developing COVID-19 in Peru and 67,000 of them are on antiretroviral therapy (ART) and at risk of limitations in their access to ART, compromising their adherence and their health during the pandemic. Finally, the potential effect of the pandemic on the mental health of PLWH is not documented. This opinion aims to: describe the clinical implications of the HIV/SARS-CoV-2 coinfection; discuss the challenges to the continuity of care of PLWH in Peru during the COVID-19 crisis; and comment possible implications that the COVID-19 crisis may pose on the mental health of PLWH.

La pandemia por la COVID-19 y las medidas restrictivas de distanciamiento social pueden interactuar con la epidemia de VIH de múltiples formas. Existen aproximadamente 87 000 personas viviendo con VIH (PVV) en el Perú quienes están en riesgo de contraer la COVID-19; 67 000 de ellas que reciben tratamiento antirretroviral (TAR) podrían tener limitaciones en el acceso a sus medicamentos, comprometiendo su adherencia y su salud. Además, el efecto que podría tener la pandemia en la salud mental de PVV en Perú aún no está esclarecido. Este artículo tiene como finalidad describir las implicancias clínicas de la coinfección VIH/SARS-CoV-2; discutir los desafíos en la continuidad de atención de las PVV en el Perú durante la crisis sanitaria por la COVID-19; y comentar las posibles implicancias de las medidas restrictivas sobre la salud mental de las PVV.

Los desafíos en la continuidad de atención de personas viviendo con VIH en el Perú durante la pandemia de la COVID-19 / Challenges to the continuity of care of people living with HIV throughout the COVID-19 crisis in Peru

RESUMEN La pandemia por la COVID-19 y las medidas restrictivas de distanciamiento social pueden interactuar con la epidemia de VIH de múltiples formas. Existen aproximadamente 87 000 personas viviendo con VIH (PVV) en el Perú quienes están en riesgo de contraer la COVID-19; 67 000 de ellas que reciben tratamiento antirretroviral (TAR) podrían tener limitaciones en el acceso a sus medicamentos, comprometiendo su adherencia y su salud. Además, el efecto que podría tener la pandemia en la salud mental de PVV en Perú aún no está esclarecido. Este artículo tiene como finalidad describir las implicancias clínicas de la coinfección VIH/SARS-CoV-2; discutir los desafíos en la continuidad de atención de las PVV en el Perú durante la crisis sanitaria por la COVID-19; y comentar las posibles implicancias de las medidas restrictivas sobre la salud mental de las PVV.

ABSTRACT The COVID-19 pandemic and societal response implemented may interact with the ongoing HIV epidemic in multiple ways. There are approximately 87000 people living with HIV (PLWH) who are at risk of developing COVID-19 in Peru and 67,000 of them are on antiretroviral therapy (ART) and at risk of limitations in their access to ART, compromising their adherence and their health during the pandemic. Finally, the potential effect of the pandemic on the mental health of PLWH is not documented. This opinion aims to: describe the clinical implications of the HIV/SARS-CoV-2 coinfection; discuss the challenges to the continuity of care of PLWH in Peru during the COVID-19 crisis; and comment possible implications that the COVID-19 crisis may pose on the mental health of PLWH.

Los desafíos en la continuidad de atención de personas viviendo con VIH en el Perú durante la pandemia de la COVID-19 / Challenges to the continuity of care of people living with HIV throughout the COVID-19 crisis in Peru

RESUMEN La pandemia por la COVID-19 y las medidas restrictivas de distanciamiento social pueden interactuar con la epidemia de VIH de múltiples formas. Existen aproximadamente 87 000 personas viviendo con VIH (PVV) en el Perú quienes están en riesgo de contraer la COVID-19; 67 000 de ellas que reciben tratamiento antirretroviral (TAR) podrían tener limitaciones en el acceso a sus medicamentos, comprometiendo su adherencia y su salud. Además, el efecto que podría tener la pandemia en la salud mental de PVV en Perú aún no está esclarecido. Este artículo tiene como finalidad describir las implicancias clínicas de la coinfección VIH/SARS-CoV-2; discutir los desafíos en la continuidad de atención de las PVV en el Perú durante la crisis sanitaria por la COVID-19; y comentar las posibles implicancias de las medidas restrictivas sobre la salud mental de las PVV.

ABSTRACT The COVID-19 pandemic and societal response implemented may interact with the ongoing HIV epidemic in multiple ways. There are approximately 87000 people living with HIV (PLWH) who are at risk of developing COVID-19 in Peru and 67,000 of them are on antiretroviral therapy (ART) and at risk of limitations in their access to ART, compromising their adherence and their health during the pandemic. Finally, the potential effect of the pandemic on the mental health of PLWH is not documented. This opinion aims to: describe the clinical implications of the HIV/SARS-CoV-2 coinfection; discuss the challenges to the continuity of care of PLWH in Peru during the COVID-19 crisis; and comment possible implications that the COVID-19 crisis may pose on the mental health of PLWH.

Parental Antibiotic Use in Urban and Peri-Urban Health Care Centers in Lima: A Cross-Sectional Study of Knowledge, Attitudes, and Practices.

In pediatric patients, the antibiotic use is affected by parental beliefs and practices; especially in countries where it is possible to acquire them without prescription. This study aims to describe the knowledge, attitudes, and practices on antibiotic use among parents of children from urban and peri-urban health care centers in Lima. A cross-sectional study was performed at 1 urban and 2 peri-urban health care centers selected in Lima, Perú. Parents of children below the age of 3 years answered a knowledge-attitudes-practices-validated questionnaire about antibiotic use and were categorized as high, moderate, and low knowledge regarding antibiotics. We analyzed potential determinants for low knowledge and having medicated their children with unprescribed antibiotics using bivariate and multivariate analyses. A total of 224 parents were enrolled, and 8% were categorized as low knowledge. Half of the parents could not recognize that antibiotics cannot cure viral infections, 59.4% disagreed with "antibiotics speed up recovery from a cold," and 53.2% stored antibiotics at home. Remarkably 23.5% of parents reported having medicated their children with antibiotics without prescription, which was associated with belonging to the peri-urban health care center, use of antibiotics by their children in the last 12 months, and having purchased antibiotics without physicians' prescription. An alarming overuse of antibiotics without prescription was described among children below the age of 3 years. Educational interventions, addressing parental attitudes and practices, and health policies should be developed to limit inappropriate antibiotic use especially in peri-urban communities.

Alta frecuencia de sintomatología depresiva en cuidadores de pacientes pediátricos en diálisis peritoneal y hemodiálisis en un hospital público de Lima / High frequency of depressive symptoms in caregivers of pediatric patients on peritoneal dialysis and hemodialysis in a public Hospital in Lima

Objetivo: El objetivo del estudio fue describir la frecuencia de sintomatología depresiva en cuidadores de pacientes pediátricos en diálisis peritoneal y hemodiálisis. Material y Métodos: Estudio descriptivo de corte transversal en el cual participaron 33 cuidadores de pacientes pediátricos con enfermedad renal crónica de la unidad de hemodiálisis y diálisis peritoneal del Hospital Cayetano Heredia en Lima (Perú). El nivel de sintomatología depresiva de los cuidadores fue evaluado mediante el Patient Health Questionnaire (PHQ-9). Resultados: Un total de 54,54% de cuidadores presentaron sintomatología depresiva; el 9,09% moderadamente severa, el 18,18% moderada y el 27,27% leve; solo el 3,03% reportó uso de antidepresivos. Todos los cuidadores con depresión moderada y moderadamente severa reportaron algún grado de dificultad para realizar sus labores. Conclusiones: Se evidenció una alta frecuencia de sintomatología depresiva en cuidadores de pacientes pediátricos en diálisis. El reconocimiento de la depresión en los cuidadores principales es importante a fin de conducir intervenciones dirigidas a la preservación de su bienestar emocional.

Objective: To describe the frequency of depressive symptomatology in caregivers of pediatric patients on peritoneal dialysis and hemodialysis. Material and methods: Descriptive, cross-sectional study of 33 caregivers of pediatric patients with Chronic Kidney Disease, under treatment in the Hemodialysis and Peritoneal Dialysis Unit of the Cayetano Heredia Hospital in Lima (Peru). The participants completed the Patient Health Questionnaire (PHQ-9), which assessed their degree of depressive symptomatology. Results: A total of 54.54% of caregivers showed depressive symptomatology; 9.09% moderately severe, 18.18% moderate and 27.27% mild; only 3.03% reported intake of antidepressants. All caregivers with moderate and moderately severe depression reported some degree of difficulty in performing their tasks. Conclusions: A high frequency of depressive symptomatology in caregivers of pediatric patients on dialysis was found. The recognition of depression in primary caregivers is important, in order to carry out interventions aimed at maintaining their emotional well-being.

Retained surgical stents as a cause of biliary obstruction in pediatric liver transplants.

BACKGROUND: Small-caliber plastic stents are sometimes placed across the hepaticojejunostomy in liver transplant recipients at the time of biliary reconstruction. These stents usually pass spontaneously, but they can be retained and, rarely, this may cause biliary obstruction. OBJECTIVE: The purpose of this paper is twofold: to describe the appearance of biliary tract obstruction caused by retained surgical stents in pediatric liver transplants, and to report how these stents can be removed using interventional radiology techniques. MATERIALS AND METHODS: Three pediatric patients presenting with biochemical and imaging evidence of biliary obstruction were encountered over a 6-month period. At percutaneous cholangiography all patients were found to have retained surgical stents which appeared to be causing biliary tract obstruction. Percutaneous snaring of the stents was undertaken. RESULTS: All stents were successfully removed using interventional radiology techniques, and follow-up showed no evidence of recurrent obstruction. CONCLUSION: Surgical stents in children undergoing hepaticojejunostomy may be retained and cause biliary obstruction. Radiologists involved with imaging these patients should be aware of this potential cause of biliary obstruction. This complication is amenable to interventional radiology techniques with good long-term results. There is no easy endoscopic or surgical treatment option in these patients.

A non-invasive method of quantifying pancreatic volume in mice using micro-MRI.

In experimental models of pancreatic growth and recovery, changes in pancreatic size are assessed by euthanizing a large cohort of animals at varying time points and measuring organ mass. However, to ascertain this information in clinical practice, patients with pancreatic disorders routinely undergo non-invasive cross-sectional imaging of the pancreas using magnetic resonance imaging (MRI) or computed tomography (CT). The aim of the current study was to develop a thin-sliced, optimized sequence protocol using a high field MRI to accurately calculate pancreatic volumes in the most common experimental animal, the mouse. Using a 7 Telsa Bruker micro-MRI system, we performed abdominal imaging in whole-fixed mice in three standard planes: axial, sagittal, and coronal. The contour of the pancreas was traced using Vitrea software and then transformed into a 3-dimensional (3D) reconstruction, from which volumetric measurements were calculated. Images were optimized using heart perfusion-fixation, T1 sequence analysis, and 0.2 to 0.4 mm thick slices. As proof of principle, increases in pancreatic volume among mice of different ages correlated tightly with increasing body weight. In summary, this is the first study to measure pancreatic volumes in mice, using a high field 7 Tesla micro-MRI and a thin-sliced, optimized sequence protocol. We anticipate that micro-MRI will improve the ability to non-invasively quantify changes in pancreatic size and will dramatically reduce the number of animals required to serially assess pancreatic growth and recovery.

A sparse based approach for detecting activations in fMRI.

In this paper, we propose a simple approach for detecting activated voxels in fMRI data by exploiting the inherent sparsity property of the BOLD signal. The proposed approach addresses the solution of the inverse problem induced by the General Linear Model through an l(0)-regularized Least Absolute Deviation (l(0)-LAD) regression method. Under this framework, the activated voxels are detected by a two-stages process: estimation and basis selection. First, an estimate of the coefficients that minimizes the absolute deviation error is found by means of the weighted median operator. Then, a thresholding operator is applied on the estimated value in order to decide whether or not a stimulus is present in the observed BOLD signal. The threshold parameter turns out to be the regularization parameter that controls the model sparseness. The method was proven on real fMRI data leading to similar activated regions than those activated by the Statistical Parametric Mapping (SPM) software.

Review of outcomes of primary liver cancers in children: our institutional experience with resection and transplantation.

BACKGROUND: Operative intervention plays an important role in the management of primary liver cancers in children. Recent improvements in diagnostic modalities, pre- and postoperative chemotherapy, and operative technique have all led to improved survival in these patients. Both hepatic resection and orthotopic liver transplantation are effective operations for pediatric liver tumors; which intervention is pursued is based on preoperative extent of disease. This is a review of our institution's experience with operative management of pediatric liver cancer over an 18-year period. METHODS: A retrospective chart review from 1990 to 2007 identified patients who were ≤18 years old who underwent operative intervention for primary liver cancer. Demographics, type of operation, intraoperative details, pre- and postoperative management, as well as outcomes were recorded for all patients. RESULTS: Fifty-four patients underwent 57 operations for primary liver cancer, 30 of whom underwent resection; the remaining 27 underwent orthotopic liver transplantation. The mean age at diagnosis was 41 months. Twenty patients had stage 1 or 2 disease and 34 patients had stage 3 or 4 disease. Forty-eight (89%) patients received preoperative chemotherapy. Postoperative chemotherapy was given to 92% of patients. Mean overall and intensive care unit duration of stay were 18 and 6 days, respectively. About 45% of patients had a postoperative complication, including hepatic artery thrombosis (n = 8), line sepsis (n = 6), mild acute rejection (n = 3), biliary stricture (n = 2), pneumothorax (n = 2), incarcerated omentum (n = 1), Horner's syndrome (n = 1), and urosepsis (n = 1). Only 6 patients had a recurrence of their cancer, 5 after liver resection, 3 of whom later received a transplant. There was only 1 recurrence after liver transplantation. There was 1 perioperative mortality from cardiac arrest. Overall survival was 93%. CONCLUSION: Operative intervention plays a critical role in the management of primary liver cancer in the pediatric population. Neoadjuvant chemotherapy can be given if the tumor seems unresectable at diagnosis. If chemotherapy is unable to sufficiently downstage the tumor, orthotopic liver transplantation becomes the patient's best option. Our institution has had considerable experience with both resection and liver transplantation in the treatment of pediatric primary liver cancer, with good long-term outcomes.

Inducción de placas ateromatosas en ratas Wistar crónicamente infectadas con Trypanosoma cruzi: alimentadas con dieta rica en grasas / Induction of atheromatous plaques in Wistar rats chronically infected with Trypanosoma cruzi: fed high fat diet

En el presente trabajo se investiga la inducción de placas ateromatosas en ratas albinas machos, cepa Wistar (Rattus norvegicus) crónicamente infectadas con Trypanosoma cruzi y alimentadas ad libitum con una dieta rica en grasas de origen vegetal, durante tres meses. La infección crónica evidenciada por pruebas sero-parasitológicas, reveló presenciade anticuerpos IgG anti- T. cruzi y ausencia de parasitemiaspatentes. La dieta rica en grasas produjo en las ratas infectadas (A) y sanas (C) un aumento significativo en el peso (P<0,05), en comparación con las ratas controles (B) y sanas (D) sometidas a la dieta normal. El estudio histopatológicode secciones de la arteria aorta de las ratas del grupo A (infectadas/dieta grasa), mostró abundantes depósitoslipídicos, procesos inflamatorios (vasculitis) y placas ateromatosas en formación. En las secciones de corazón y músculo esquelético se evidenció miocarditis y miositis con características de cronicidad sin parasitismo tisular. Las pruebas inmunohistoquímicas aplicadas a los cortes de arteria,corazón y músculo esquelético de las ratas infectadas A (infectadas/dieta-grasa) y B (infectadas/dieta-normal), mostraron abundantes depósitos antigénicos, lo que indica persistencia de antígenos parasitarios. En conclusión, las ratasinfectadas con T. cruzi alimentadas con la dieta rica en grasas, tienen una mayor propección a desarrollar placas ateromatosas.Los resultados demostraron que una dieta hiperlipídicaes un factor de riesgo para el desarrollo de enfermedadateromatosa en individuos con enfermedad de Chagas

This work is focused on the induction of atheromatous plaques in male albino rats (Rattus norvegicus), Wistar, chronically infected with Trypanosoma cruzi and fed ad libitum with diet rich in fats of vegetal origin, during three months. The chronic infection detected by serological and parasitological assays, revealed the presence of antibodies IgG anti- T. cruzi and the absence of patents parasitemias. The diet rich in fats produced in the group of infected rats (A) and the group of healthy rats (C) a significant increase in the weight (P<0,05), in comparison with the control group of infected rats (B) and the group of healthy rats (D), fed with a normal diet. The histopathological study of sections of the aorta arteryof the rats of the group (A) (infected/diet fat), showed abundants lipid deposits, inflammatory processes (vasculitis) and atheromatous plaques in development. The sections of the heart and skeletal muscle showed pictures of a myocarditis and myositis with features of chronic tissue without parasitism. The immunohistochemestry assays applied to the cuts of artery, heart and skeletal muscle of the infected rats A (diet/fat) and B (normal/diet), showed abundants antigen deposits. In conclusion, the rats chronically infected with T. cruzi and fed with a diet rich in fats, have a main propensity to develop atheromatous plaques. The results showed that a hyperlipidic diet is a risk factor for the development of atheromatous disease in individuals with Chagas`disease

Corrección de línea base en datos electroforéticos usando optimización local del algoritmo legend en el dominio wavelet / A baseline correction algorithm for capillary electrophoresis data using local optimization of the legend algorithm in the wavelet domain / Correção de linha base em dados electroforéticos usando otimização local do algoritmo "legend" no domínio wavelet

Se propone un método de corrección de la línea base (LB) de señales electroforéticas que explota la representación wavelet a baja resolución de la señal original. La LB es modelada en el dominio wavelet como una función polinomial y se usa el algoritmo de optimización LEGEND para determinar los parámetros del modelo polinomial que mejor se ajusta a una subsección de la LB, de forma tal de minimizar una función costo asimétrica robusta. El algoritmo propuesto produce una corrección adecuada de la LB en aquellas zonas del electroferograma donde se aprecian sustancias de baja concentración en las adyacencias de sustancias de concentración elevada, preservando picos asociados con las primeras. Se validó el algoritmo desarrollado en un problema de medición de la cantidad de glutamato presente en 24 registros electroforéticos y se comparó su desempeño con los valores medidos por el especialista donde la línea base es corregida en forma manual y con los valores arrojados por un segundo algoritmo de corrección de LB recientemente propuesto.

A baseline (BL) correction algorithm for capillary electrophoresis (CE) data is developed. The proposed algorithm exploits a low-resolution wavelet representation of the original signal to locally model the BL as a polinomial function and applies the LEGEND optimization algorithm to obtain the model parameters, such that a robust non-symmetric cost function is minimized. The proposed algorithm outputs a suitable BL correction on those subsections of the electropherogram where peaks related to low concentration substances are near those of high concentration substances. The performance of the proposed algorithm was tested by measuring the glutamate mass on 24 electropherograms after the BL had been suppressed using the proposed algorithm. The resulting values are compared to those yielded by a conventional measuring method performed by a CE specialist and by a second CE baseline correction method recently introduced.

É proposto um método de correção da linha base (LB) de sinais eletroforéticos que explora a representação wavelet a baixa resolução do sinal original. A LB é modelada no dominio wavelet como uma função polinomial e se usa o algoritmo de otimização LEGEND para determinar os parâmetros do modelo polinomial que melhor se ajusta a uma subseção da LB, de forma tal de minimizar uma função custo assimétrica robusta. O algoritmo proposto produz uma correção adequada da LB naquelas áreas do eletroferograma onde se apreciam substâncias de baixa concentração nas adjacências de substâncias de concentração elevada, preservando picos associados com as primeiras. Validou-se o algoritmo desenvolvido em um problema de medição da quantidade de glutamato presente em 24 registros eletroforéticos e foi comparado seu desempenho com os valores medidos pelo especialista onde a linha base é corrigida em forma manual e com os valores emitidos por um segundo algoritmo de correção de LB recentemente proposto.

Pattern recognition in capillary electrophoresis data using dynamic programming in the wavelet domain.

A novel approach for CE data analysis based on pattern recognition techniques in the wavelet domain is presented. Low-resolution, denoised electropherograms are obtained by applying several preprocessing algorithms including denoising, baseline correction, and detection of the region of interest in the wavelet domain. The resultant signals are mapped into character sequences using first derivative information and multilevel peak height quantization. Next, a local alignment algorithm is applied on the coded sequences for peak pattern recognition. We also propose 2-D and 3-D representations of the found patterns for fast visual evaluation of the variability of chemical substances concentration in the analyzed samples. The proposed approach is tested on the analysis of intracerebral microdialysate data obtained by CE and LIF detection, achieving a correct detection rate of about 85% with a processing time of less than 0.3 s per 25,000-point electropherogram. Using a local alignment algorithm on low-resolution denoised electropherograms might have a great impact on high-throughput CE since the proposed methodology will substitute automatic fast pattern recognition analysis for slow, human based time-consuming visual pattern recognition methods.

Improving immunization of programmable logic controllers using weighted median filters.

This paper addresses the problem of improving immunization of programmable logic controllers (PLC's) to electromagnetic interference with impulsive characteristics. A filtering structure, based on weighted median filters, that does not require additional hardware and can be implemented in legacy PLC's is proposed. The filtering operation is implemented in the binary domain and removes the impulsive noise presented in the discrete input adding thus robustness to PLC's. By modifying the sampling clock structure, two variants of the filter are obtained. Both structures exploit the cyclic nature of the PLC to form an N-sample observation window of the discrete input, hence a status change on it is determined by the filter output taking into account all the N samples avoiding thus that a single impulse affects the PLC functionality. A comparative study, based on a statistical analysis, of the different filters' performances is presented.

Multichannel image compression by bijection mappings onto zero-trees.

A new approach to multichannel image compression is introduced where the intra- and cross-band correlations are jointly exploited in a surprisingly simple yet very effective manner. The key component of the algorithm is a bijection mapping of the original multichannel image into a virtual two-dimensional (2-D) scalar image. By optimally mapping the multichannel image set into a 2-D array and by subsequently applying a scalar image coding algorithm, the spatial correlation and the spectral correlation of the multichannel data set are jointly exploited. Based on the statistical characteristics of the multichannel data, the bijection mapping can be optimized to minimize the distortion introduced by the compression algorithm. The optimization reduces to the maximization of a function of the second-order statistics of the multichannel data. At high compression rates, the new algorithm outperforms traditional compression algorithms whenever the cross-band correlation is high and it yields comparable performance at low compression rates.

Weighted median image sharpeners for the World Wide Web.

A class of robust weighted median (WM) sharpening algorithms is developed in this paper. Unlike traditional linear sharpening methods, weighted median sharpeners are shown to be less sensitive to background random noise or to image artifacts introduced by JPEG and other compression algorithms. These concepts are extended to include data dependent weights under the framework of permutation weighted medians leading to tunable sharpeners that, in essence, are insensitive to noise and compression artifacts. Permutation WM sharpeners are subsequently generalized to smoother/sharpener structures that can sharpen edges and image details while simultaneously filter out background random noise. A statistical analysis of the various algorithms is presented, theoretically validating the characteristics of the proposed sharpening structures. A number of experiments are shown for the sharpening of JPEG compressed images and sharpening of images with background film-grain noise. These algorithms can prove useful in the enhancement of compressed or noisy images posted on the World Wide Web (WWW) as well as in other applications where the underlying images are unavoidably acquired with noise.