Crystallization tendencies of modelled Lennard-Jones liquids with different attractions.

Molecular dynamics simulations are performed on simple models composed of monoatomic Lennard-Jones atoms for which the repulsive interaction is the same but the attractive part is tuned. We investigate the precise role of the attractive part of the interaction potential on different structural, dynamical, and thermodynamical properties of these systems in the liquid and crystalline states. It includes crystallization trends for which the main physical ingredients involved have been computed: the diffusion coefficient, the Gibbs energy difference between the liquid and the crystalline state, and the crystal-liquid interfacial free energy. Results are compared with predictions from the classical nucleation theory including transient and steady-state regimes at moderate and deeper undercooling. The question of the energetic and entropic impact of the repulsive and attractive part of the interaction potential towards crystallization is also addressed.

Real-time parameter estimation of Zika outbreaks using model averaging.

Early prediction of the final size of any epidemic and in particular for Zika disease outbreaks can be useful for health authorities in order to plan the response to the outbreak. The Richards model is often been used to estimate epidemiological parameters for arboviral diseases based on the reported cumulative cases in single- and multi-wave outbreaks. However, other non-linear models can also fit the data as well. Typically, one follows the so called post selection estimation procedure, i.e., selects the best fitting model out of the set of candidate models and ignores the model uncertainty in both estimation and inference since these procedures are based on a single model. In this paper we focus on the estimation of the final size and the turning point of the epidemic and conduct a real-time prediction for the final size of the outbreak using several non-linear models in which these parameters are estimated via model averaging. The proposed method is applied to Zika outbreak data in four cities from Colombia, during the outbreak ocurred in 2015-2016.

The impact of maternal obesity on iron status, placental transferrin receptor expression and hepcidin expression in human pregnancy.

BACKGROUND: Obesity is associated with decreased iron status, possibly due to a rise in hepcidin, an inflammatory protein known to reduce iron absorption. In animals, we have shown that maternal iron deficiency is minimised in the foetus by increased expression of placental transferrin receptor (pTFR1), resulting in increased iron transfer at the expense of maternal iron stores. OBJECTIVE: This study examines the effect of obesity during pregnancy on maternal and neonatal iron status in human cohorts and whether the placenta can compensate for decreased maternal iron stores by increasing pTFR1 expression. SUBJECTS/METHODS: A total of 240 women were included in this study. One hundred and fifty-eight placentas (Normal: 90; Overweight: 37; Obese: 31) were collected at delivery. Maternal iron status was measured by determining serum transferrin receptor (sTFR) and ferritin levels at 24 and 34 weeks and at delivery. Hepcidin in maternal and cord blood was measured by ELISA and pTFR1 in placentas by western blotting and real-time RT-PCR. RESULTS: Low iron stores were more common in obese women. Hepcidin levels (ng ml(-1)) at the end of the pregnancy were higher in obese than normal women (26.03±12.95 vs 18.00±10.77, P<0.05). Maternal hepcidin levels were correlated with maternal iron status (sTFR r=0.2 P=0.025), but not with neonatal values. mRNA and protein levels of pTFR1 were both inversely related to maternal iron status. For mRNA and all women, sTFR r=0.2 P=0.044. Ferritin mRNA levels correlated only in overweight women r=-0.5 P=0.039 with hepcidin (r=0.1 P=0.349), irrespective of maternal body mass index (BMI). CONCLUSIONS: The data support the hypothesis that obese pregnant women have a greater risk of iron deficiency and that hepcidin may be a regulatory factor. Further, we show that the placenta responds to decreased maternal iron status by increasing pTFR1 expression.

Truck traffic related air pollution associated with asthma symptoms in young boys: a cross-sectional study.

OBJECTIVES: The aim of this study was to evaluate the influence of intensity of truck traffic on asthma symptomatology, and its relationship with age and gender. STUDY DESIGN: A cross-sectional study was conducted on children and adolescents from Galicia (North-West Spain). METHODS: Following the methodology of the International Study of Asthma and Allergies in Childhood (ISAAC): children from schools randomly selected, answered a self-administered questionnaire included questions on asthma symptoms and some risk factors. The association between self-reported truck traffic on the street of residence and symptoms of asthma were investigated by logistic regression adjusted for body mass index, maternal education and parental smoking. RESULTS: Almost 40% of children in Galicia are exposed to the frequent and constant passing of heavy goods vehicles. The odds of 6-7 year-old boys having severe or exercise induced asthma is tripled when they live in streets with the constant passing of heavy goods vehicles, compared with those living in streets where these vehicles never pass. In adolescents and 6-7 year-old girls, no relationship was observed between truck traffic and asthma symptoms. CONCLUSIONS: The results of this study appear to support a distinct effect of truck traffic on asthma symptoms depending on the age and sex of the exposed population, being more harmful for young males.

Trends of asthma mortality in Galicia from 1993 to 2007.

INTRODUCTION: In the past few years, deaths due to asthma appear to decrease at least in Western countries; but there are significant variations between populations. The aim of this study is to describe the trends in deaths due to asthma between 1993 and 2007 in our community and to analyze any factors associated with this. METHODS: All cases, which had asthma as a cause of death, were included in the study. The mortality data were obtained from the official death certificate from the Deaths Register. Mortality relative risk, based on the calendar year, sociodemographic variables (age and gender), seasons, and days of the week, were estimated using a Poisson generalized linear model with a log-link. RESULTS: In the 15 years of the study period, a total of 1180 people had died due to asthma, mainly in winter (34.5%), women (64.5%), and advanced age (65 years or above; 84.6%). A tendency of decreased mortality in all age groups was observed during the period of the study, which was significant in both the sexes in the 35- to 64-year-old age group, and in males above 65 years. CONCLUSION: Death due to asthma is changing favorably in our community, with a tendency to decrease in the past few years. Advanced age, being female, and the winter period are associated with a higher mortality rate due to asthma.

Magnet ingestion knows no borders: A threat for Latin American children.

INTRODUCTION AND AIMS: The ingestion of foreign bodies, such as magnets, is a potentially lethal accident that affects children and is associated with bleeding and gastrointestinal perforation, as well as death. There are no Latin American reports in the literature on cases of magnet ingestion in children. Our aim was to establish whether said ingestion has been seen by pediatric endoscopists and gastroenterologists in Latin America, to determine the scope of that potential threat in their patient populations. MATERIALS AND METHODS: We collected data regarding endoscopies performed on children in Latin America, within the time frame of 2017-2019, through questionnaires that were distributed to pediatric endoscopists at the 2nd World Congress of Gastrointestinal Endoscopy (ENDO 2020). The questionnaires provided information on foreign body location, the presence and number of ingested magnets, and the description of complications and surgical interventions. RESULTS: Our cohort from 12 Latin American countries reported 2,363 endoscopies due to foreign body ingestion, 25 (1.05%) of which were the result of having swallowed one or more magnets. Mean patient age was 5.14 years (SD 2.5) and 10 (40%) of the cases were girls. Three (12%) of the patients presented with severe complications and 2 (8%) cases required surgery. CONCLUSIONS: Our preliminary study suggests that the ingestion of magnets is not common in Latin American countries, but said cases are frequently associated with complications. Constant monitoring of the incidence of such cases is extremely important, so that through education and awareness of those events, life-threatening complications in children can be prevented.

Quality of life and persistent symptoms after hospitalization for COVID-19. A prospective observational study comparing ICU with non-ICU patients.

BACKGROUND: Hospitalized COVID-19 patients are prone to develop persistent symptoms and to show reduced quality of life following hospital admission. METHODS: Prospective cohort study of COVID-19 patients admitted to a hospital from March 1 to April 30, 2020. The primary outcome was to compare health related quality of life and persistent symptoms six months after hospital admission, of COVID-19 patients who required ICU admission with those who did not. RESULTS: Among the 242 patients hospitalized during the defined period of time, 44 (18.2%) needed ICU admission. Forty (16.5%) patients died during hospital admission. Two hundred and two (83.5%) patients were discharged alive from the hospital. At six months, 183 (75.6%) patients completed the questionnaires (32 ICU patients and 151 non ICU patients). Ninety-six (52.4%) reported decreased quality of life and 143 (78.1%) described persistent symptoms. More ICU patients showed worsening of their quality of life (71.9% vs 43.7%, P=0.004). There were no differences in the proportion of patients with persistent symptoms between ICU and non ICU patients (87.5% vs 76.2%, P=0.159). ICU patients showed more frequently dyspnea on exertion (78.1% vs 47.7%, P=0.02), dyspnea on light exertion (37.5% vs 4.6%, P<0.001), and asthenia (56.3 vs 29.1, P=0.003). CONCLUSIONS: Survivors of COVID-19 needing hospitalization had persistent symptoms and a decline in the quality of life. ICU patients referred a large decrease of their quality of life compared with non ICU patients.

Recurrence of primary spontaneous pneumothorax: Associated factors.

INTRODUCTION: Determining the risk of recurrence of primary spontaneous pneumothorax is challenging. The objective of this study was to develop a risk assessment model to predict the probability of recurrence in patients with spontaneous pneumothorax. METHODS: A retrospective study was performed of all episodes of pneumothorax diagnosed in the last 12 years in a hospital, in patients not initially submitted to surgery. Logistic regression was used to estimate the probability of recurrence. Based on a set of variables, a predictive model was built with its corresponding ROC curve to determine its discrimination power and diagnostic precision. RESULTS: Of the 253 patients included, 128 (50.6%) experienced recurrence (37% within the first year). Recurrence was detected within 110 days in 25% of patients. The median of time to recurrence for the whole population was 1120 days. The presence of blebs/bullae was found to be a risk factor of recurrence (OR: 5.34; 95% CI: 2.81-10.23; p=0.000), whereas chest drainage exerted protective effect (OR: 0.19; 95% CI: 0.08-0.40; p=0.000). The variables included in the regression model constructed were hemoglobin and leukocyte count in blood, treatment received, and presence of blebs/bullae, with a fair discriminative power to predict recurrence [AUC=0.778 (95% CI: 0.721-0.835)]. CONCLUSION: The overall recurrence rate was high and was associated with the presence of blebs/bullae, failure to perform an active intervention (chest drainage) and low levels of hemoglobin and leukocytes in blood. Recurrence rarely occurs later than three years after the first episode. Once validated, this precision model could be useful to guide therapeutic decisions.

[Quality of life and persistent symptoms after hospitalization for COVID-19. A prospective observational study comparing ICU with non-ICU patients]. / Calidad de vida y síntomas persistentes tras hospitalización por COVID-19. Estudio observacional prospectivo comparando pacientes con o sin ingreso en UCI.

Background: Hospitalized COVID-19 patients are prone to develop persistent symptoms and to show reduced quality of life following hospital admission. Methods: Prospective cohort study of COVID-19 patients admitted to a hospital from March 1 to April 30, 2020. The primary outcome was to compare health related quality of life and persistent symptoms six months after hospital admission, of COVID-19 patients who required ICU admission with those who did not. Results: Among the 242 patients hospitalized during the defined period of time, 44 (18.2%) needed ICU admission. Forty (16.5%) patients died during hospital admission. Two hundred and two (83.5%) patients were discharged alive from the hospital. At six months, 183 (75.6%) patients completed the questionnaires (32 ICU patients and 151 non ICU patients). Ninety-six (52.4%) reported decreased quality of life and 143 (78.1%) described persistent symptoms. More ICU patients showed worsening of their quality of life (71.9 vs. 43.7%, P = 0.004). There were no differences in the proportion of patients with persistent symptoms between ICU and non ICU patients (87.5 vs. 76.2%, P = 0.159). ICU patients showed more frequently dyspnea on exertion (78.1 vs. 47.7%, P = 0.02), dyspnea on light exertion (37.5 vs. 4.6%, P < 0.001), and asthenia (56.3 vs. 29.1, P = 0.003). Conclusions: Survivors of COVID-19 needing hospitalization had persistent symptoms and a decline in the quality of life. ICU patients referred a large decrease of their quality of life compared with non ICU patients.

Magnet ingestion knows no borders: A threat for Latin American children. / La ingestión de imanes no conoce fronteras: una amenaza para los niños latinoamericanos.

INTRODUCTION AND AIMS: The ingestion of foreign bodies, such as magnets, is a potentially lethal accident that affects children and is associated with bleeding and gastrointestinal perforation, as well as death. There are no Latin American reports in the literature on cases of magnet ingestion in children. Our aim was to establish whether said ingestion has been seen by pediatric endoscopists and gastroenterologists in Latin America, to determine the scope of that potential threat in their patient populations. MATERIALS AND METHODS: We collected data regarding endoscopies performed on children in Latin America, within the time frame of 2017-2019, through questionnaires that were distributed to pediatric endoscopists at the 2nd World Congress of Gastrointestinal Endoscopy (ENDO 2020). The questionnaires provided information on foreign body location, the presence and number of ingested magnets, and the description of complications and surgical interventions. RESULTS: Our cohort from 12 Latin American countries reported 2,363 endoscopies due to foreign body ingestion, 25 (1.05%) of which were the result of having swallowed one or more magnets. Mean patient age was 5.14years (SD2.5) and 10 (40%) of the cases were girls. Three (12%) of the patients presented with severe complications and 2 (8%) cases required surgery. CONCLUSIONS: Our preliminary study suggests that the ingestion of magnets is not common in Latin American countries, but said cases are frequently associated with complications. Constant monitoring of the incidence of such cases is extremely important, so that through education and awareness of those events, life-threatening complications in children can be prevented.

Recent epidemiological trends in extrapulmonary TB in Galicia, Spain.

OBJECTIVE: To describe the epidemiological trends and characteristics of extrapulmonary tuberculosis (EPTB) in Galicia, Spain, from 2000 to 2019.METHODS: This was a retrospective cohort study based on data from the Galician TB information system.RESULTS: Of the total number of TB cases (n = 15,871), 5,428 (34.2%) had EPTB. The absolute number of cases and incidence of EPTB decreased dramatically (from 480 cases and 17.8 cases/100,000 in 2000, to 172 and 6.4 cases/100,000 in 2019, respectively), with a mean annual decrease of respectively 64% and 4.7% for absolute cases and incidence rates. The risk for EPTB was higher in men than in women (RR 3.86, 95% CI 3.66-4.07). The most frequent age group was 15-44 years (2,234 patients, 41.2%); overall reductions per age group were 82% (0-14 years), 75% (15-44 years), 44% (45-64 years) and 63% (≥65 years), with statistically significant differences. The most frequently locations were the pleura (1,916 cases; 35.3%) and the lymph nodes (1,504; 27.7%).CONCLUSION: The incidence of EPTB in Galicia has decreased significantly in the last 20 years. The epidemiological characteristics have not changed, except for the number of patients with risk factors. This improvement of EPTB epidemiological trends coincides with the implementation of the programme for the prevention and control of TB, which suggests that it has been very effective in the control of the EPTB.

Gut microbiota composition is associated with body weight, weight gain and biochemical parameters in pregnant women.

Obesity is associated with complications during pregnancy and increased health risks in the newborn. The objective of the present study was to establish possible relationships between gut microbiota, body weight, weight gain and biochemical parameters in pregnant women. Fifty pregnant women were classified according to their BMI in normal-weight (n 34) and overweight (n 16) groups. Gut microbiota composition was analysed by quantitative real-time PCR in faeces and biochemical parameters in plasma at 24 weeks of pregnancy. Reduced numbers of Bifidobacterium and Bacteroides and increased numbers of Staphylococcus, Enterobacteriaceae and Escherichia coli were detected in overweight compared with normal-weight pregnant women. E. coli numbers were higher in women with excessive weight gain than in women with normal weight gain during pregnancy, while Bifidobacterium and Akkermansia muciniphila showed an opposite trend. In the whole population, increased total bacteria and Staphylococcus numbers were related to increased plasma cholesterol levels. Increased Bacteroides numbers were related to increased HDL-cholesterol and folic acid levels, and reduced TAG levels. Increased Bifidobacterium numbers were related to increased folic acid levels. Increased Enterobacteriaceae and E. coli numbers were related to increased ferritin and reduced transferrin, while Bifidobacterium levels showed the opposite trend. Therefore, gut microbiota composition is related to body weight, weight gain and metabolic biomarkers during pregnancy, which might be of relevance to the management of the health of women and infants.

Diagnostic value of interleukin-12 p40 in tuberculous pleural effusions.

The diagnosis of tuberculous pleural effusion (TBPE) is frequently problematic. Several markers of TBPE in pleural fluid have been evaluated, with different results. Pleural effusions from 96 patients were classified on the basis of definitive diagnosis as tuberculous (n = 39), neoplastic (n = 42) or parapneumonic (n = 15). Adenosine deaminase (ADA), ADA isoform ADA-2, interferon (IFN)-gamma, CD3(+)/DR(+) T-lymphocytes and interleukin (IL)-12 p40 were determined in all 96 effusions. The efficiency of IL-12 p40 for diagnosis of TBPEs was evaluated, in comparison with those of the other parameters, by comparing the areas under their receiver operating characteristics. With the threshold value of 550 pg.mL(-1), IL-12 p40 had a sensitivity of 92.3% (36 out of 39) and specificity of 70.2% (17 false positives). The misclassification rate of IL-12 p40 was significantly greater than those of ADA-2 and ADA. Among TBPEs, ADA correlated significantly with ADA-2, and IFN-gamma with ADA and IL-12 p40. Although tuberculous pleural effusions show values of interleukin-12 p40 that are significantly higher than neoplastic and parapneumonic fluids, this parameter is less efficient than adenosine deaminase, adenosine deaminase isoform 2 and interferon-gamma. Its routine determination is, accordingly, not justified.

Mixing effects in glass-forming Lennard-Jones mixtures.

Mixing effects have been investigated from molecular dynamics simulations at constant number of particles, volume, and temperature on the Kob-Andersen glass-forming Lennard-Jones atomic mixture A(x)B(1-x) for 0 < or = x < or = 1 compositions. Upon cooling, crystallization is observed for x < or = 0.5 and x > or = 0.9 compositions. The crystalline states can be described by a quite complex coexistence of voids (x < or = 0.5), point defects, and one or two crystal structures which were characterized and found identical to those reported by Fernandez and Harrowell [Phys. Rev. E 67, 011403 (2003)] from energy minimization. Amorphization is also seen at 0.6 < or = x < or = 0.8 compositions and it is suggested that both crystal structures, CsCl and fcc-hcp, do not compete at these compositions since only one type of crystalline seed is found in the liquid, either fcc/hcp or CsCl. A significant decrease in the diffusion constants for both A and B particles is also seen above x(A) approximately = 0.5. The problem of the extraordinary stability of the model against crystallization is discussed.

[Accidental genital myiasis by Eristalis tenax]. / Miasis genital accidental por Eristalis tenax.

Myiasis is a parasitic infestation of human or animal skin, necrotic tissues and natural cavities by fly larvae or pupa. In this paper we will describe the case of a 27 years old woman, asymptomatic, that spontaneously eliminated from her vagina two Eristalis tenax larvae, a worldwide distributed fly specie, classified as an accidental myiasis agent. The patient lived in an urban area, she had low socioeconomic status and she had the antecedent record of use of intravaginal vegetables as sexual stimulator. Analyzing the case and the references, we concluded the patient had an accidental infestation by E. tenax, being the vaginal introduction of vegetables the most probable mechanism of transmission. This kind of infestation has not been communicated in the literature. Also, this is the first documented case of E. tenax myiasis in Chile.

[Thoracentesis in Primary Care]. / Toracocentesis en Atención Primaria.

Thoracentesis is a simple test with few complications that provides relevant information in the diagnosis of a pleural effusion, through a correct interpretation of the pleural fluid analysis. An interesting initiative would be to incorporate this technique by those Primary Care teams that treat serious and complex patients, with difficulties in moving to specialised centres far from their homes. In this context, a good knowledge of the diagnostic possibilities offered by the pleural fluid analysis could be very useful in the hands of well trained staff to establish the aetiology of a pleural effusion and be able to initiate, as quickly as possible, its treatment. This article aims to contribute to this, by suggesting guidelines on how a simple technique can provide relevant information in order to determine the aetiology of pleural effusion, and which could be implemented within a given Primary Care framework.

Diaphragmatic dysfunction.

The diaphragm is the main breathing muscle and contraction of the diaphragm is vital for ventilation so any disease that interferes with diaphragmatic innervation, contractile muscle function, or mechanical coupling to the chest wall can cause diaphragm dysfunction. Diaphragm dysfunction is associated with dyspnoea, intolerance to exercise, sleep disturbances, hypersomnia, with a potential impact on survival. Diagnosis of diaphragm dysfunction is based on static and dynamic imaging tests (especially ultrasound) and pulmonary function and phrenic nerve stimulation tests. Treatment will depend on the symptoms and causes of the disease. The management of diaphragm dysfunction may include observation in asymptomatic patients with unilateral dysfunction, surgery (i.e., plication of the diaphragm), placement of a diaphragmatic pacemaker or invasive and/or non-invasive mechanical ventilation in symptomatic patients with bilateral paralysis of the diaphragm. This type of patient should be treated in experienced centres. This review aims to provide an overview of the problem, with special emphasis on the diseases that cause diaphragmatic dysfunction and the diagnostic and therapeutic procedures most commonly employed in clinical practice. The ultimate goal is to establish a standard of care for diaphragmatic dysfunction.

Beta-lactam activity against penicillin-resistant Streptococcus pneumoniae strains exhibiting higher amoxicillin versus penicillin minimum inhibitory concentration values: an in vitro pharmacodynamic simulation.

BACKGROUND: Activity of simulated serum concentrations after oral therapy with 400 mg cefditoren pivoxil b.i.d., 500 mg cefuroxime axetil b.i.d. and 875/125 mg amoxicillin/clavulanic acid b.i.d. and t.i.d. regimens was explored over 24 h against Streptococcus pneumoniae. METHODS: Computerized pharmacodynamic simulations were performed against strains with penicillin/amoxicillin/cefuroxime/cefditoren minimum inhibitory concentrations (MICs, microg/ml) and serotypes: strain 1 (0.25/0.12/1/0.12; serotype 6A), strain 2 (2/4/ 2/0.25; serotype 6B), strain 3 (4/16/4/0.5; serotype 14), and strain 4 (4/16/8/1; serotype 14). RESULTS: Bactericidal activity (> or =3 log(10) reduction) at 12 and 24 h was obtained against all strains with cefditoren, against strains 1 and 2 with cefuroxime and amoxicillin/clavulanic acid t.i.d., but only against strain 1 with amoxicillin/clavulanic acid b.i.d.. Bactericidal activity at 24 h was related to T > MIC of >30% dosing interval, 1.7-2.0 log(10) reductions with T > MIC of 20-30%, and <1 log(10) reduction or regrowth with T > MIC of 0%. CONCLUSIONS: It is difficult to achieve pharmacodynamic coverage and bactericidal activity by physiological concentrations of oral beta-lactams against penicillin-resistant pneumococcal strains exhibiting higher amoxicillin versus penicillin MICs. Cefditoren may offer alternatives.

[Study of maternal nutrition and genetic on the foetal adiposity programming (The PREOBE study)]. / Estudio de la influencia de la nutrición y genética maternas sobre la programación del desarrollo del tejido adiposo fetal (Estudio PREOBE).

BACKGROUND: Maternal genetics and feeding before and during pregnancy, different maternal metabolic pathologies, as well as nutrient intakes of newborns in their first months of life may be involved in the obesity aetiology and its long-term consequences. The possible role of these and others factors, the mechanisms and the effects on the metabolism, and the development of this disease need further research. OBJECTIVE: To acquire more knowledge about foetal adipose tissue development and the influence of genetic, dietetic and environmental factors on the risk to suffer from obesity. METHODOLOGY: Four study groups have been established with 30 pregnant women in each one: 1) control group; 2) mothers with glucose intolerance/gestational diabetes; 3) women with low weight gain during pregnancy, and 4) women with overweight/obesity at the beginning of the pregnancy. The magnitudes to be studied are: 1) dietary intake; 2) life-style habits; 3) physical activity; 4) anthropometry and body composition; 5) haematological study; 6) biochemical study (lipid and metabolic biomarkers); 7) immune function profile related to nutritional status; 8) psychological profile; 9) genetic biomarkers, and 10) microbiological markers; all of them in relation to the development of the foetal adipose tissue in the first stages of life and the risk of suffering from obesity in the future. CONCLUSION: This project, coordinated by the Department of Paediatrics of the School of Medicine in the University of Granada, and with the collaboration of well-known and expert research groups, tries to contribute to the knowledge about the obesity aetiology in infancy and its subsequent development in later periods of life.

Characteristics of patients with myelomatous pleural effusion. A systematic review. / Características de los pacientes con derrame pleural mielomatoso. Revisión sistemática.

BACKGROUND: Myelomatous pleural effusion (MPE) is rare in multiple myeloma, and therefore its characteristics are not well defined. METHODS: A systematic review (4 online databases) was conducted of articles describing the clinical characteristics of patients with MPE, pleural effusion's biochemical characteristics and treatment efficacy. We analysed isolated cases and small retrospective series. RESULTS: We included 98 articles with a total of 153 patients with MPE. The median age was 62years, and the ratio of males to females was 1.7:1. The most common symptoms were dyspnoea (98.8%), bone pain (100%) and chest pain (95.3%), and the most relevant abnormal laboratory test results were anaemia (90.1%) and renal failure (53.8%). MPE was predominantly unilateral (63.9%) and covered more than two-thirds of the hemithorax (54.5%). The pleural fluid (PF) had a haematologic/serohaematologic appearance (87%) and met the criteria for lymphocytic (78.6%) exudate (94.7%). The most cost-effective diagnostic procedures were pleural cytology (95.9%) and the observation of a monoclonal peak in the PF (94.7%). In a significant proportion of patients (54.7%), the MPE did not respond to treatment, and the best response was achieved when chemotherapy (with/without corticosteroids) was combined with therapeutic thoracentesis, chest drainage or pleurodesis. CONCLUSIONS: MPE predominates in middle to older age men, is symptomatic and is usually unilateral. PF is an exudate with a haemorrhagic appearance, and the most cost-effective diagnostic procedure is pleural cytology. Treatment response is unfavourable in more than half of patients.