Scientific research in obstructive sleep apnea syndrome: bibliometric analysis in SCOPUS, 1991-2012.

PURPOSE: The research in obstructive sleep apnea (OSA) may be beneficial from the collaboration between countries and researchers. In this study, we aimed to analyze the scientific research on OSA from 1991 to 2012 and to evaluate the collaboration networks between countries. METHODS: We conducted a bibliometric study in the SCOPUS database. The systematic search was limited to "articles" published from 1991 to 2012. Articles are results of original research; we evaluated the following criteria: number of countries represented, number of authors, number of citations, and journal names. We determined which countries were the most productive (more articles published) and the number of collaborations between these countries. The probability of citation was evaluated using adjusted odds ratios in a logistic regression analysis. RESULTS: We found a total of 6,896 OSA-related articles that had been published in 1,422 journals, 50 % of these articles were concentrated in 41 journals. Of the 74 different countries associated with these articles, the USA had the highest involvement with 23.8 % of all articles published. The probability of citation increased by 1.23 times for each additional author, and by 2.23 times for each additional country represented; these findings were independent of time since publication, journal, or the country of the author. CONCLUSIONS: Scientific production on OSA is increasing with limited international collaboration. The country with the greatest production in this period (1991-2012) was the USA, which concentrated the international collaboration network on OSA. We recommended that articles should be produced with international collaboration to improve the quantity of scientific publications and their chances of publication in high impact journals.

Sleepiness and nocturnal hypoxemia in Peruvian men with obstructive sleep apnea.

PURPOSE: To evaluate the intensity of nocturnal hypoxemia associated with sleepiness in Peruvian men with a diagnosis of obstructive sleep apnea (OSA). METHODS: We carried out a secondary data analysis based on a study which includes patients with OSA who were seen in a private hospital in Lima, Peru from 2006 to 2012. We included male adults who had polysomnographic recordings and who answered the Epworth sleepiness scale (ESE). The intensity of nocturnal hypoxemia (oxygen saturation ≤90%) was classified in four new categories: 0, <1, 1 to 10 and >10% total sleep time with nocturnal hypoxemia (NH). When the ESE score was higher than 10, we used the definitions presence or absence of sleepiness. We used Poisson regression models with robust variance to estimate crude and adjusted prevalence ratios (PR) for association between sleepiness and NH. RESULTS: 518 male patients with OSA were evaluated. Four hundred and fifty-two (87%) patients had NH and 262 (51%) had sleepiness. Of the 142 (27.4%) patients who had >10% total sleep time with NH, 98 (69.0%) showed sleepiness and had a greater probability of sleepiness prevalence, with a crude PR of 1.82 (95% CI 1.31-2.53). This association persisted in the multivariate models. CONCLUSIONS: We found an association between NH and sleepiness. Only patients with the major intensity of NH (over 10% of the total sleep time) had a greater probability of sleepiness. This suggests that sleepiness probably occurs after a chronic process and after overwhelming compensatory mechanisms.

Brainstem auditory evoked potentials in newborn infants born in a high-altitude area. / Potenciales evocados auditivos de tronco en neonatos nacidos a gran altitud.

Introduction. A non-invasive and safe way to assess neurophysiological parameters in newborn infants is the evaluation of brainstem auditory evoked potentials (BAEPs). Objective. To assess the latencies and wave intervals of BAEPs in healthy newborn infants born in a high-altitude area (Cusco, 3399 MASL). Population and methods. Cross-sectional and prospective study. Newborn infants younger than 14 days of age, discharged less than 7 days after birth, were assessed to determine BAEP values at intensities of 70 dB, 80 dB, and 90 dB. The study variables were gestational age, birth weight, and type of delivery. The median differences in wave latencies and intervals were estimated according to gestational age and birth weight. Results. A total of 96 newborn infants (17 preterm infants) were assessed. The median latencies of waves I-V at 90 dB were for wave I: 1.56 ms, wave II: 2,74 ms, wave III: 4.37 ms, wave IV: 5.62 ms, and wave V: 6.63 ms. The latency of wave I for 80 dB was 1.71 ms and for 70 dB, 1.88 ms. Wave intervals (I-III, III-V, I-V) were 2.8 ms, 2.2 ms, and 5.0 ms, respectively, without differences among intensities (p > 0.05). Prematurity and low birth weight were associated with a longer wave I latency (p < 0.05). Conclusions. Here we describe adjusted BAEP latency and interval values for newborn infants born at high altitude. At different sound intensities, we identified differences in wave latencies, but not in interwave intervals.

Introducción. Una forma no invasiva y segura de evaluar los parámetros neurofisiológicos en recién nacidos es la evaluación de los potenciales evocados auditivos del tronco encefálico (PEAT). Objetivo. Evaluar las latencias e intervalos de ondas de los PEAT en neonatos sanos nacidos a gran altitud (Cusco, 3399 msnm). Población y métodos. Estudio transversal y prospectivo. Se incluyeron neonatos menores a 14 días de vida, dados de alta a menos de 7 días de nacidos, evaluados para determinar los valores de los PEAT a intensidades sonoras de 70 dB, 80 dB y 90 dB. Se incluyeron las variables edad gestacional, peso al nacer, tipo de parto. Se calcularon las diferencias de las medianas de las latencias e intervalos de las ondas según edad gestacional y peso al nacer. Resultados. Se evaluaron 96 neonatos (17 pretérminos). Las medianas de las latencias de las ondas I a V a 90 dB fueron las siguientes: onda I 1,56 ms; onda II 2,74 ms; onda III 4,37 ms; onda IV 5,62 ms, onda V 6,63 ms. La latencia de la onda I para 80 dB fue de 1,71 ms y para 70 dB de 1,88 ms. Los intervalos para las ondas (I-III), (III-V) y (I-V) fueron de 2,8 ms, 2,2 ms y 5,0 ms respectivamente, sin diferencias entre intensidades (p >0,05). La prematuridad y el bajo peso estuvieron asociados a latencias de la onda I más prolongadas (p <0,05). Conclusiones. Se presentan valores ajustados de latencias e intervalos de los PEAT en neonatos nacidos a gran altitud. Se identificó que, a distintas intensidades sonoras, se ven diferencias en las latencias de las ondas, pero no en los intervalos entre ondas.

[Scientific production in clinical medicine and international collaboration networks in South American countries]. / Redes de colaboración y producción científica sudamericana en medicina clínica, ISI Current Contents 2000-2009.

BACKGROUND: International collaboration is increasingly used in biomedical research. AIM: To describe the characteristics of scientific production in Latin America and the main international collaboration networks for the period 2000 to 2009. MATERIAL AND METHODS: Search for papers generated in Latin American countries in the Clinical Medicine database of ISI Web of Knowledge v.4.10 - Current Contents Connect. The country of origin of the corresponding author was considered the producing country of the paper. International collaboration was analyzed calculating the number of countries that contributed to the generation of a particular paper. Collaboration networks were graphed to determine the centrality of each network. RESULTS: Twelve Latin American countries participated in the production of 253,362 papers. The corresponding author was South American in 79% of these papers. Sixteen percent of papers were on clinical medicine and 36% of these were carried out in collaboration. Brazil had the highest production (22,442 papers) and the lower percentage of international collaboration (31%). North America accounts for 63% of collaborating countries. Only 8% of collaboration is between South American countries. Brazil has the highest tendency to collaborate with other South American countries. CONCLUSIONS: Brazil is the South American country with the highest scientific production and indicators of centrality in South America. The most common collaboration networks are with North American countries.

Prediction of Blood Viscosity Based on Usual Hematological Parameters in a Clinically Healthy Population Living in a High-Altitude City.

Huamaní, Charles, William Sarmiento, Golda Córdova-Heredia, Luz Cruz-Huanca, Paulina Damián-Saavedra, and Dario Antonio. Prediction of blood viscosity based on usual hematological parameters in a clinically healthy population living in a high-altitude city. High Alt Med Biol. 23:78-84, 2022. Background and Aims: Variations in blood viscosity are mainly determined by the hematocrit level, but in residents of high-altitude cities, the hemoglobin levels and blood viscosity values are often high. We aimed to determine the blood viscosity values in clinically healthy chronic hypoxia-acclimatized individuals and establish a predictive model based on the hematocrit level and other common hematological parameters. Methods: A prospective observational study was conducted in asymptomatic young adults living in Cusco (a city located at 3,399 m). Venous blood samples were collected to determine the hemoglobin, hematocrit, and albumin and serum protein levels and blood viscosity values. Results: Altogether, 253 volunteers were included, of whom 147 (58.1%) were women. The hematological values were mean values of hemoglobin, 16.32 ± 2.0 g/dl; hematocrit, 48.12% ± 5.24%; triglycerides, 130.68 ± 90.64 mg/dl; globulin, 3.07 ± 0.36 g/dl; and mean blood viscosity, 6.17 ± 0.94 centipoises. The prediction model with the highest explained variance (R2 = 68.07%) and parsimony conservation comprised hematocrit, globulin, and triglycerides [blood viscosity = hematocrit × (0.176) + globulin × (0.595) + triglycerides × (1.77/1,000) - 4.13]. Conclusions: In a population living at high altitude, the blood viscosity level is extremely high and mainly determined by the hematocrit level. This population has chronic high blood viscosity levels, which can be predicted using other blood elements.

SARS-CoV-2 seroprevalence in a high-altitude setting in Peru: adult population-based cross-sectional study.

BACKGROUND: There are several ecological studies, but few studies of the prevalence of SARS-COV-2 at high altitude. We aimed to estimate the population-based seroprevalence of SARS-COV-2 in three settings of Cusco at the end of the first wave among adults. METHODS: A population-based survey was conducted in September 2020, in three settings in the region of Cusco: (1) Cusco city at 3,300 meters above the sea level (m.a.s.l.), (2) the periphery of Cusco (Santiago, San Jerónimo, San Sebastián, and Wanchaq) at 3,300 m.a.s.l., and (3) Quillabamba city, located at 1,050 m.a.s.l. People aged ≥ 18 years within a family unit were included. The diagnosis of SARS-CoV-2 infection was based on identifying anti- SARS-CoV-2 total antibodies (IgM and IgG) in serum using the Elecsys Anti-SARS-CoV-2 chemiluminescence test. RESULTS: We enrolled 1924 participants from 712 families. Of the total, 637 participants were anti-SARS-CoV-2 seropositive. Seroprevalence was 38.8% (95% CI [33.4%-44.9%]) in Cusco city, 34.9% (95% CI [30.4%-40.1%]) in the periphery of Cusco, and 20.3% (95% CI [16.2%-25.6%]) in Quillabamba. In 141 families (19.8%; 95% CI [17.0%-22.8%]) the whole members were positive to the test. Living with more than three persons in the same house, a positive COVID-19 case at home, and a member who died in the last five months were factors associated with SARS-COV-2 seropositivity. Dysgeusia/dysosmia was the symptom most associated with seropositivity (aPR = 2.74, 95% CI [2.41-3.12]); whereas always wearing a face shield (aPR = 0. 73; 95% CI [0.60-0.89]) or a facial mask (aPR = 0.76, 95% CI [0.63-0. 92) reduced that probability. CONCLUSIONS: A great proportion of Cusco's city inhabitants presented anti-SARS-CoV-2 antibodies at the end of the first wave, with significant differences between settings. Wearing masks and face shields were associated with lower rate of seropositivity; however, efforts must be made to sustain them over time since there is still a high proportion of susceptible people.

Estimated conditions to control the covid-19 pandemic in peruvian pre- and post-quarantine scenarios. / Condiciones estimadas para controlar la pandemia de COVID-19 en escenarios de pre y poscuarentena en el Perú.

OBJECTIVES: To determine the probability of controlling the outbreak of COVID-19 in Peru, in a pre- and post-quarantine scenario using mathematical simulation models. MATERIALS AND METHODS: Outbreak si mulations for the COVID-19 pandemic are performed, using stochastic equations under the following assumptions: a pre-quarantine population R0 of 2.7 or 3.5, a post-quarantine R0 of 1.5, 2 or 2.7, 18% or 40%, of asymptomatic positives and a maximum response capacity of 50 or 150 patients in the intensive care units. The success of isolation and contact tracing is evaluated, no other mitigation measures are included. RESULTS: In the pre-quarantine stage, success in controlling more than 80% of the simulations occurred only if the isolation of positive cases was implemented from the first case, after which there was less than 40% probability of success. In post-quarantine, with 60 positive cases it is necessary to isolate them early, track all of their contacts and decrease the R0 to 1.5 for outbreak control to be successful in more than 80% of cases. Other scenarios have a low probability of success. CONCLUSIONS: The control of the outbreak in Peru during pre-quarantine stage demanded requirements that were difficult to comply with, therefore quarantine was necessary; to successfully suspend it would require a significant reduction in the spread of the disease, early isolation of positives and follow-up of all contacts of positive patients.

OBJETIVOS: Determinar la probabilidad de control del brote de la COVID-19 en el Perú, en un escenario pre y poscuarentena en modelos de simulaciones matemáticas. MATERIALES Y MÉTODOS: Se realizan simu laciones de brotes para la pandemia de COVID-19, usando ecuaciones estocásticas bajo los siguientes supuestos: un R0 poblacional precuarentena de 2,7 o 3,5, y un R0 poscuarentena de 1,5, 2 o 2,7, positivos asintomáticos del 18% o 40%, y una capacidad resolutiva máxima de 50 o 150 pacientes en las unidades de cuidados intensivos. Se evalúa el éxito del aislamiento y rastreo de contactos, no se incluyen otras medidas de mitigación. RESULTADOS: En la etapa precuarentena, el éxito en el control de más del 80% de las simulaciones se daba solo si el aislamiento de casos positivos se implantaba desde el primer caso, luego se tenía menos de un 40% de probabilidad de éxito. En la poscuarentena, con 60 casos positivos es necesario aislarlos precozmente, rastrear al 100% sus contactos y disminuir el R0 a 1,5 para que el control del brote tenga éxito en más del 80% de los casos. Otros escenarios tienen baja probabilidad de éxito. CONCLUSIONES: El control del brote en el Perú en la etapa precuarentena demandaba requisitos de difícil cumplimiento, por ello la cuarentena era necesaria; para suspenderla con éxito se requeriría una impor tante reducción de la dinámica de propagación de la enfermedad, el aislamiento precoz de los positivos y el seguimiento de todos los contactos.

Importancia de la medición de la Viscosidad sanguínea: retos y limitaciones

La sangre es una mezcla de componentes que tiene su propia identidad. Una de las propiedades físicas que adquiere es su viscosidad, la cual es la resistencia que ofrece para desplazarse. A diferencia de sus componentes (como glucosa, hemoglobina, colesterol, etc.), la sangre no posee un nivel único de viscosidad, sino que esta es variable debido a diversos factores. Exponemos algunos principios físicos que nos permitirán entender mejor esta dinámica de la viscosidad sanguínea, y su posible aplicación en algunos fenómenos hemodinámicos, así como la complejidad de su medición en la práctica clínica habitual.

Blood is a mixture of components that has its own identity. One of the physical properties that it acquires is its viscosity, which is the resistance it offers to move. Unlike its components (such as glucose, hemoglobin, cholesterol, etc.), blood does not have a single level of viscosity, but it is variable due to various factors. We present some physical principles that will allow us to better understand these dynamics of blood viscosity, and its possible application in some hemodynamic phenomena, as well as the complexity of its measurement in routine clinical practice.

Radiodensidad de la arteria cerebral media y su correlación con el nivel de hemoglobina en pacientes con y sin infarto cerebral residentes a gran altitud

Introducción. El signo de la arteria cerebral media (ACM) hiperdensa evaluada por tomografía simple permite predecir la enfermedad vascular cerebral isquémica (EVCi) con oclusión de un gran vaso, sin embargo, es frecuente identificar este signo en pobladores con niveles altos de hemoglobina sin clínica de EVCi. Objetivos. Evaluar la correlación entre la radiodensidad de la ACM y el nivel de hemoglobina en pacientes con y sin EVCi, residentes en una ciudad a gran altitud. Métodos. Estudio observacional analítico, se incluyeron personas residentes de Cusco (ubicada a 3300 msnm) que acudían al servicio de emergencia y se les realizó una tomografía cerebral, presentando o no clínica de EVCi. Se realizó la medición de la radiodensidad de la ACM y se correlacionó con el nivel de hemoglobina. Resultados. Se incluyeron 279 pacientes, el promedio de hemoglobina fue de 15,1 mg/dL y desviación estándar (DE) de 2,5 mg/dL, en los controles se identificó una correlación significativa (r = 0,425, p<0,01) entre la radiodensidad de la ACM con el nivel de hemoglobina. En los casos con EVCi derechos, la radiodensidad de la ACM derecha fue de 46,9 (DE = 7,7 UH) y de la izquierda fue de 46,1 (DE = 6,6 UH), sin que existan diferencias estadísticas (p = 0,24). Tampoco se encontró diferencias en los casos con EVCi izquierdos. Conclusión. Sí existe una correlación entre la radiodensidad de la ACM con el nivel de hemoglobina en los pobladores que viven a gran altitud, sin embargo, no se logró demostrar diferencias significativas entre la radiodensidad entre las ACM afectada y la contralateral en los casos de un EVCi.

Introduction. The sign of the hyperdense middle cerebral artery (MCA) evaluated by simple tomography allows predicting ischemic cerebrovascular disease (ICD) with occlusion of a large vessel, however, it is common to identify this sign in residents with high hemoglobin levels without symptoms of ICD. Objectives. To evaluate the correlation between the radiodensity of the MCA and the hemoglobin level in patients with and without ICD, residing in a high-altitude city. Methods. Analytical observational study, including people residing in Cusco (located at 3300 masl) who attended the emergency service and underwent a brain tomography, presenting or not ICD symptoms. ACM radiodensity was measured and correlated with the hemoglobin level. Results. 279 patients were included, the average hemoglobin was 15.1 and standard deviation (DE) of 2.5 mg/dL, in the controls a significant correlation was identified (r = 0.425, p<0.01) between the radiodensity of the MCA with the hemoglobin level. In the cases with right ICD, the radiodensity of the right MCA was 46.9 (DE = 7.7 HU) and of the left it was 46.1 (DE = 6.6 HU), with no statistical differences (p=0 ,24). No differences were found in the cases with left ICD either. Conclusion. There is a correlation between the radiodensity of the MCA with the hemoglobin level in the inhabitants who live at high altitudes, however, it is not possible to demonstrate significant differences between the radiodensity between the affected MCA and the contralateral one in the cases of an ICD.

Potenciales evocados auditivos de tronco en neonatos nacidos a gran altitud / Brainstem auditory evoked potentials in newborn infants born in a high-altitude area

Introducción. Una forma no invasiva y segura de evaluar los parámetros neurofisiológicos en recién nacidos es la evaluación de los potenciales evocados auditivos del tronco encefálico (PEAT). Objetivo. Evaluar las latencias e intervalos de ondas de los PEAT en neonatos sanos nacidos a gran altitud (Cusco, 3399 msnm). Población y métodos. Estudio transversal y prospectivo. Se incluyeron neonatos menores a 14 días de vida, dados de alta a menos de 7 días de nacidos, evaluados para determinar los valores de los PEAT a intensidades sonoras de 70 dB, 80 dB y 90 dB. Se incluyeron las variables edad gestacional, peso al nacer, tipo de parto. Se calcularon las diferencias de las medianas de las latencias e intervalos de las ondas según edad gestacional y peso al nacer. Resultados. Se evaluaron 96 neonatos (17 pretérminos). Las medianas de las latencias de las ondas I a V a 90 dB fueron las siguientes: onda I 1,56 ms; onda II 2,74 ms; onda III 4,37 ms; onda IV 5,62 ms, onda V 6,63 ms. La latencia de la onda I para 80 dB fue de 1,71 ms y para 70 dB de 1,88 ms. Los intervalos para las ondas (I-III), (III-V) y (I-V) fueron de 2,8 ms, 2,2 ms y 5,0 ms respectivamente, sin diferencias entre intensidades (p >0,05). La prematuridad y el bajo peso estuvieron asociados a latencias de la onda I más prolongadas (p <0,05). Conclusiones. Se presentan valores ajustados de latencias e intervalos de los PEAT en neonatos nacidos a gran altitud. Se identificó que, a distintas intensidades sonoras, se ven diferencias en las latencias de las ondas, pero no en los intervalos entre ondas.

Introduction. A non-invasive and safe way to assess neurophysiological parameters in newborn infants is the evaluation of brainstem auditory evoked potentials (BAEPs). Objective. To assess the latencies and wave intervals of BAEPs in healthy newborn infants born in a high-altitude area (Cusco, 3399 MASL). Population and methods. Cross-sectional and prospective study. Newborn infants younger than 14 days of age, discharged less than 7 days after birth, were assessed to determine BAEP values at intensities of 70 dB, 80 dB, and 90 dB. The study variables were gestational age, birth weight, and type of delivery. The median differences in wave latencies and intervals were estimated according to gestational age and birth weight. Results. A total of 96 newborn infants (17 preterm infants) were assessed. The median latencies of waves I­V at 90 dB were for wave I: 1.56 ms, wave II: 2,74 ms, wave III: 4.37 ms, wave IV: 5.62 ms, and wave V: 6.63 ms. The latency of wave I for 80 dB was 1.71 ms and for 70 dB, 1.88 ms. Wave intervals (I­III, III­V, I­V) were 2.8 ms, 2.2 ms, and 5.0 ms, respectively, without differences among intensities (p > 0.05). Prematurity and low birth weight were associated with a longer wave I latency (p < 0.05). Conclusions. Here we describe adjusted BAEP latency and interval values for newborn infants born at high altitude. At different sound intensities, we identified differences in wave latencies, but not in interwave intervals.

Dominance and leadership in research activities: Collaboration between countries of differing human development is reflected through authorship order and designation as corresponding authors in scientific publications.

INTRODUCTION: Scientific collaboration is an important mechanism that enables the integration of the least developed countries into research activities. In the present study, we use the order of author signatures and addresses for correspondence in scientific publications as variables to analyze the interactions between countries of very high (VHHD), high (HHD), medium (MHD), and low human development (LHD). METHODOLOGY: We identified all documents published between 2011 and 2015 in journals included in the Science Citation Index-Expanded categories' of Tropical Medicine, Infectious Diseases, Parasitology, and Pediatrics. We then classified the countries participating in the publications according to their Human Development Index (HDI), analyzing the international collaboration; positioning and influence of some countries over others in cooperative networks; their leadership; and the impact of the work based on the HDI and the type of collaboration. RESULTS: We observed a high degree of international collaboration in all the areas analyzed, in the case of both LHD and MHD countries. We identified numerous cooperative links between VHHD countries and MHD/LHD countries, reflecting the fact that cooperative links are an important mechanism for integrating research activities into the latter. The countries with large emerging economies, such as Brazil and China stand out due to the dominance they exert in the collaborations established with the United States, the UK, and other European countries. The analysis of the leadership role of the countries, measured by the frequency of lead authorships, shows limited participation by MHD/LHD countries. This reduced participation among less developed countries is further accentuated by their limited presence in the addresses for correspondence. We observed significant statistical differences in the degree of citation according to the HDI of the participating countries. CONCLUSIONS: The order of signatures and the address for correspondence in scientific publications are bibliographic characteristics that facilitate a precise, in-depth analysis of cooperative practices and their associations with concepts like dominance or leadership. This is useful to monitor the existing balance in research participation in health research publications.

Consenso peruano para el uso de la resonancia magnética en el diagnóstico y seguimiento de pacientes con esclerosis múltiple / Peruvian consensus for the use of Magnetic Resonance Imaging in the diagnosis and follow-up of patients with Multiple Sclerosis

RESUMEN El uso de la resonancia magnética (RM) en el diagnóstico y seguimiento de pacientes con esclerosis múltiple (EM) ha optimizado el cuidado de los pacientes afectados. Diversos grupos internacionales de trabajo han intentado clarificar y normatizar el uso global de la RM pero, en muchas ocasiones, se extrapolan datos de otras regiones que no contemplan la realidad de cada lugar o son difíciles de implementar. Objetivo: Consensuar aspectos relacionados con el uso de RM en el diagnóstico y seguimiento de pacientes con EM en el Perú. Material y Métodos: Un grupo de expertos peruanos, conformado por neurólogos y radiólogos, condujo la elaboración del consenso mediante metodología de ronda de encuestas a la distancia. Resultados: Las recomendaciones, basadas en la evidencia publicada y en el criterio de los expertos, enfocaron tanto el rol de las técnicas convencionales de RM como el de la medición de la atrofia cerebral en pacientes con EM al momento del diagnóstico y durante el periodo de seguimiento. Conclusiones: Las recomendaciones del consenso podrán potencialmente homogenizar y optimizar el cuidado y seguimiento de pacientes con EM en nuestro país.

SUMMARY The use of Magnetic Resonance Imaging (MRI) in the diagnosis and follow-up of patients with Multiple Sclerosis (MS) has optimized the care of the affected patients. Several international working groups have tried to clarify and standardize the global use of MRI but, on many occasions, data are extrapolated from other regions, do not contemplate local realities or are difficult to implement. Objective: To reach a consensus on aspects related to the use of MRI in the diagnosis and follow-up of patients with MS in Peru. Material and Methods: A group of Peruvian experts (neurologists and radiologists) worked on the elaboration of the consensus using a remote survey round methodology. Results: The recommendations, established on the basis of published evidence and on the experts' criteria, focused on the role of both, the conventional MRI techniques and the measurement of brain atrophy in MS patients both at the time of diagnosis and during the follow-up period Conclusions: The consensual recommendations could potentially assist in the standardization and optimization of the care and follow-up of patients with MS in our country.

HUMAN T-LYMPHOTROPIC VIRUS 1 (HTLV-1) AND HUMAN T-LYMPHOTROPIC VIRUS 2 (HTLV-2): GEOGRAPHICAL RESEARCH TRENDS AND COLLABORATION NETWORKS (1989-2012).

Publications are often used as a measure of research work success. Human T-lymphotropic virus (HTLV) type 1 and 2 are human retroviruses, which were discovered in the early 1980s, and it is estimated that 15-20 million people are infected worldwide. This article describes a bibliometric review and a coauthorship network analysis of literature on HTLV indexed in PubMed in a 24-year period. A total of 7,564 documents were retrieved, showing a decrease in the number of documents from 1996 to 2007. HTLV manuscripts were published in 1,074 journals. Japan and USA were the countries with the highest contribution in this field (61%) followed by France (8%). Production ranking changed when the number of publications was normalized by population (Dominican Republic and Japan), by gross domestic product (Guinea-Bissau and Gambia), and by gross national income per capita (Brazil and Japan). The present study has shed light on some of the defining features of scientific collaboration performed by HTLV research community, such as the existence of core researchers responsible for articulating the development of research in the area, facilitating wider collaborative relationships and the integration of new authors in the research groups.

Clinical factors associated with extreme sleep apnoea [AHI>100 events per hour] in Peruvian patients: A case-control study-A preliminary report.

PURPOSE: The severity of obstructive sleep apnoea (OSA) ranges from mild or moderate to severe sleep apnoea. However, there is no information available on the clinical characteristics associated with cases involving more than 100 events per hour. This is a preliminary report and our goal was to characterise the demographics and sleep characteristics of patients with Extreme OSA and compare with patients with sleep apnoea of lesser severity. We hypothesised that patients with Extreme OSA (AHI>100) is associated with an increased comorbidities and/or risk factors. METHODS: We carried out a case-control study on male patients with OSA who were seen in a private hospital in Lima, Peru between 2006 and 2012. Cases were identified if their apnoea/hypopnea index (AHI) was higher than 100 (Extreme OSA), and four controls were selected per case: two with 15-29 AHI and two with 30-50 AHI, matched according to case diagnosis dates. We evaluated demographic, past medical history, and oxygen saturation variables. RESULTS: We identified 19 cases that were matched with 54 controls. In the multivariate model, only arterial hypertension, neck circumference, age, and over 10% in SatO2Hb≤90% in total sleep time (T90) were associated with Extreme OSA. Arterial hypertension had an OR=6.31 (CI95%: 1.71-23.23) of Extreme OSA. Each 5-cm increment in neck circumference was associated with an increase of OR=4.34 (CI95%: 1.32-14.33), while T90>10% had an OR=19.68 (CI95%: 4.33-89.49). Age had a marginal relevance (OR=0.95; CI95%: 0.92-0.99). CONCLUSION: Our results suggest that arterial hypertension, neck circumference, and over 10% SatO2Hb≤90% in total sleep time were associated with a higher probability of Extreme OSA. We recommend investigators to study this population of Extreme OSA looking for an early diagnosis and the identification of prognostic factors in comparison with moderate to severe levels.

Condiciones estimadas para controlar la pandemia de COVID-19 en escenarios de pre y poscuarentena en el Perú / Estimated conditions to control the covid-19 pandemic in peruvian pre- and post-quarantine scenarios

RESUMEN Objetivos: Determinar la probabilidad de control del brote de la COVID-19 en el Perú, en un escenario pre y poscuarentena en modelos de simulaciones matemáticas. Materiales y métodos: Se realizan simu laciones de brotes para la pandemia de COVID-19, usando ecuaciones estocásticas bajo los siguientes supuestos: un R0 poblacional precuarentena de 2,7 o 3,5, y un R0 poscuarentena de 1,5, 2 o 2,7, positivos asintomáticos del 18% o 40%, y una capacidad resolutiva máxima de 50 o 150 pacientes en las unidades de cuidados intensivos. Se evalúa el éxito del aislamiento y rastreo de contactos, no se incluyen otras medidas de mitigación. Resultados: En la etapa precuarentena, el éxito en el control de más del 80% de las simulaciones se daba solo si el aislamiento de casos positivos se implantaba desde el primer caso, luego se tenía menos de un 40% de probabilidad de éxito. En la poscuarentena, con 60 casos positivos es necesario aislarlos precozmente, rastrear al 100% sus contactos y disminuir el R0 a 1,5 para que el control del brote tenga éxito en más del 80% de los casos. Otros escenarios tienen baja probabilidad de éxito. Conclusiones: El control del brote en el Perú en la etapa precuarentena demandaba requisitos de difícil cumplimiento, por ello la cuarentena era necesaria; para suspenderla con éxito se requeriría una impor tante reducción de la dinámica de propagación de la enfermedad, el aislamiento precoz de los positivos y el seguimiento de todos los contactos.

ABSTRACT Objectives: To determine the probability of controlling the outbreak of COVID-19 in Peru, in a pre- and post-quarantine scenario using mathematical simulation models. Materials and methods: Outbreak si mulations for the COVID-19 pandemic are performed, using stochastic equations under the following assumptions: a pre-quarantine population R0 of 2.7 or 3.5, a post-quarantine R0 of 1.5, 2 or 2.7, 18% or 40%, of asymptomatic positives and a maximum response capacity of 50 or 150 patients in the intensive care units. The success of isolation and contact tracing is evaluated, no other mitigation measures are included. Results: In the pre-quarantine stage, success in controlling more than 80% of the simulations occurred only if the isolation of positive cases was implemented from the first case, after which there was less than 40% probability of success. In post-quarantine, with 60 positive cases it is necessary to isolate them early, track all of their contacts and decrease the R0 to 1.5 for outbreak control to be successful in more than 80% of cases. Other scenarios have a low probability of success. Conclusions: The control of the outbreak in Peru during pre-quarantine stage demanded requirements that were difficult to comply with, therefore quarantine was necessary; to successfully suspend it would require a significant reduction in the spread of the disease, early isolation of positives and follow-up of all contacts of positive patients.

Evolution of Cooperation Patterns in Psoriasis Research: Co-Authorship Network Analysis of Papers in Medline (1942-2013).

BACKGROUND: Although researchers have worked in collaboration since the origins of modern science and the publication of the first scientific journals in the eighteenth century, this phenomenon has acquired exceptional importance in the last several decades. Since the mid-twentieth century, new knowledge has been generated from within an ever-growing network of investigators, working cooperatively in research groups across countries and institutions. Cooperation is a crucial determinant of academic success. OBJECTIVE: The aim of the present paper is to analyze the evolution of scientific collaboration at the micro level, with regard to the scientific production generated on psoriasis research. METHODS: A bibliographic search in the Medline database containing the MeSH terms "psoriasis" or "psoriatic arthritis" was carried out. The search results were limited to articles, reviews and letters. After identifying the co-authorships of documents on psoriasis indexed in the Medline database (1942-2013), various bibliometric indicators were obtained, including the average number of authors per document and degree of multi-authorship over time. In addition, we performed a network analysis to study the evolution of certain features of the co-authorship network as a whole: average degree, size of the largest component, clustering coefficient, density and average distance. We also analyzed the evolution of the giant component to characterize the changing research patterns in the field, and we calculated social network indicators for the nodes, namely betweenness and closeness. RESULTS: The main active research clusters in the area were identified, along with their authors of reference. Our analysis of 28,670 documents sheds light on different aspects related to the evolution of scientific collaboration in the field, including the progressive increase in the mean number of co-authors (which stood at 5.17 in the 2004-2013 decade), and the rise in multi-authored papers signed by many different authors (in the same decade, 25.77% of the documents had between 6 and 9 co-authors, and 10.28% had 10 or more). With regard to the network indicators, the average degree gradually increased up to 10.97 in the study period. The percentage of authors pertaining to the largest component also rose to 73.02% of the authors. The clustering coefficient, on the other hand, remained stable throughout the entire 70-year period, with values hovering around 0.9. Finally, the average distance peaked in the decades 1974-1983 (8.29) and 1984-2003 (8.12) then fell over the next two decades, down to 5.25 in 2004-2013. The construction of the co-authorship network (threshold of collaboration ≥ 10 co-authored works) revealed a giant component of 161 researchers, containing 6 highly cohesive sub-components. CONCLUSIONS: Our study reveals the existence of a growing research community in which collaboration is increasingly important. We can highlight an essential feature associated with scientific collaboration: multi-authored papers, with growing numbers of collaborators contributing to them, are becoming more and more common, therefore the formation of research groups of increasing depth (specialization) and breadth (multidisciplinarity) is now a cornerstone of research success.

[Poor quality of sleep associated with low adherence to highly active antiretroviral therapy in Peruvian patients with HIV/AIDS]. / La mala calidad de sueño se asocia a una menor adherencia al tratamiento antirretroviral de gran actividad en pacientes peruanos con infección por VIH/SIDA.

This cross-sectional study analyzed the association between poor quality of sleep and adherence to highly active antiretroviral therapy (HAART) in 389 Peruvian patients with HIV/AIDS. Poor quality of sleep was measured with the Pittsburgh Sleep Quality Index (PSQI) and adherence with the CEAT-VIH (Peruvian adaptation). A Poisson generalized linear model with robust standard errors was used to estimate prevalence ratios and 95%CI. A crude model showed that mild, moderate, and severe poor quality of sleep were associated with inadequate treatment adherence. In the adjusted model for variables associated in the bivariate analysis or variables theoretically associated with adherence, only moderate/severe poor quality of sleep remained associated (PR = 1.34, 95%CI: 1.17-1.54; and PR = 1.34, 95%CI: 1.16-1.57, respectively). The study concluded that moderate/severe poor quality of sleep was independently associated with adherence to HAART. Assessing quality of sleep may be helpful in the comprehensive evaluation of HIV patients.