Exploring the Potential of Machine Learning for the Diagnosis of Balance Disorders Based on Centre of Pressure Analyses.

Balance disorders are caused by several factors related to functionality deficits in one or multiple sensory systems such as vision, vestibular, and somatosensory systems. Patients usually have difficulty explaining their dizziness, often using ambiguous words to describe their symptoms. A common practice by clinicians is to objectively evaluate the patient's dizziness by applying the Sensory Organization Test (SOT), which measures the contribution of each sensory system (vestibular, visual, somatosensory). The SOT protocol can record up to 2000 measurements in 20 s to generate the Equilibrium Score (EQS) with its five load sensors. EQS is an indicator that reflects how well a patient can maintain balance. However, its calculation only considers two instances from these 2000 measurements that reflect the maximum anterior and posterior sway angle during the test performance; therefore, there is an opportunity to perform further analysis. This article aims to use the Centre of Pressure (COP) time series generated by the SOT and describes a methodology to pre-process and reduce the dimensionality of this raw data and use it as an input for machine learning algorithms to diagnose patients with balance disorder impairments. After applying this methodology to data from 475 patients, the logistic regression model (LR) produced the highest f1-score with 76.47%, and the support vector machine (SVM) performed almost as well, with an f1-score of 76.19%.

Detección de Chlamydia trachomatis en hombres que tienen sexo con hombres en Bogotá: un estudio piloto / Detection of chlamydia trachomatis in men that have sex with men in Bogotá: a pilot study

Objetivo. Optimizar una técnica PCR que permita evaluar la presencia de C. trachomatis en hisopados anorrectales provenientes de HSH. En Colombia se notifican anualmente más de 70.000 casos nuevos de ITS, de los cuales se estima que aproximadamente el 9.3% corresponde a uretritis entre las que se encuentran las causadas por C. trachomatis. Métodos. Uno de los problemas en el método de detección de C. trachomatis por PCR en muestras de hisopado anorrectal es la extracción de ADN, el uso de equipos automatizados dispuestos en el mercado resulta costoso y en muchos de los casos no están disponibles en el laboratorio clínico de rutina. En este estudio se realizó una PCR para detección de C. trachomatis, estableciendo un protocolo para la toma de muestra y extracción de ADN a partir de hisopos anorrectales. Resultados. Se procesaron 27 muestras correspondientes a HSH voluntarios pertenecientes al Grupo de apoyo y estudio de la Diversidad Sexual (GAEDS) de la Universidad Nacional de Colombia. Se encontraron 5 muestras positivas para C. trachomatis en hombres sintomáticos y asintomáticos relacionado con el riesgo de adquirir infección por sus prácticas sexuales.

Objective. optimize a PCR technique to evaluate the presence of C. trachomatis in anorectal swabs from MSM. In Colombia there are reported each year more than 70,000 new cases of STIs, of which it is estimated that approximately 9.3% is urethritis among which are those caused by C. trachomatis. Methods. DNA extraction is one of the problems in the method of detecting C. trachomatis by PCR anorectal swab samples. Besides, the use of automated equipment arranged on the market is expensive and in many cases the samples are not available in the clinical laboratory routine. In this study it was performed PCR for detection of C. trachomatis protocol establishing the sampling and DNA extraction from anorectal swabs. Results. 27 samples were processed corresponding HSH volunteers belonging to the Support group and study of Sexual Diversity (GAEDS) of the National University of Colombia. 5 samples positive for C. trachomatis associated with both symptomatic and asymptomatic men at high risk of acquiring infection because of their sexual practices were found.

Bacterial and viral co-infections complicating severe influenza: Incidence and impact among 507 U.S. patients, 2013-14.

BACKGROUND: Influenza acts synergistically with bacterial co-pathogens. Few studies have described co-infection in a large cohort with severe influenza infection. OBJECTIVES: To describe the spectrum and clinical impact of co-infections. STUDY DESIGN: Retrospective cohort study of patients with severe influenza infection from September 2013 through April 2014 in intensive care units at 33 U.S. hospitals comparing characteristics of cases with and without co-infection in bivariable and multivariable analysis. RESULTS: Of 507 adult and pediatric patients, 114 (22.5%) developed bacterial co-infection and 23 (4.5%) developed viral co-infection. Staphylococcus aureus was the most common cause of co-infection, isolated in 47 (9.3%) patients. Characteristics independently associated with the development of bacterial co-infection of adult patients in a logistic regression model included the absence of cardiovascular disease (OR 0.41 [0.23-0.73], p=0.003), leukocytosis (>11K/µl, OR 3.7 [2.2-6.2], p<0.001; reference: normal WBC 3.5-11K/µl) at ICU admission and a higher ICU admission SOFA score (for each increase by 1 in SOFA score, OR 1.1 [1.0-1.2], p=0.001). Bacterial co-infections (OR 2.2 [1.4-3.6], p=0.001) and viral co-infections (OR 3.1 [1.3-7.4], p=0.010) were both associated with death in bivariable analysis. Patients with a bacterial co-infection had a longer hospital stay, a longer ICU stay and were likely to have had a greater delay in the initiation of antiviral administration than patients without co-infection (p<0.05) in bivariable analysis. CONCLUSIONS: Bacterial co-infections were common, resulted in delay of antiviral therapy and were associated with increased resource allocation and higher mortality.

Severe Influenza in 33 US Hospitals, 2013-2014: Complications and Risk Factors for Death in 507 Patients.

BACKGROUND: Influenza A (H1N1) pdm09 became the predominant circulating strain in the United States during the 2013-2014 influenza season. Little is known about the epidemiology of severe influenza during this season. METHODS: A retrospective cohort study of severely ill patients with influenza infection in intensive care units in 33 US hospitals from September 1, 2013, through April 1, 2014, was conducted to determine risk factors for mortality present on intensive care unit admission and to describe patient characteristics, spectrum of disease, management, and outcomes. RESULTS: A total of 444 adults and 63 children were admitted to an intensive care unit in a study hospital; 93 adults (20.9%) and 4 children (6.3%) died. By logistic regression analysis, the following factors were significantly associated with mortality among adult patients: older age (>65 years, odds ratio, 3.1 [95% CI, 1.4-6.9], P=.006 and 50-64 years, 2.5 [1.3-4.9], P=.007; reference age 18-49 years), male sex (1.9 [1.1-3.3], P=.031), history of malignant tumor with chemotherapy administered within the prior 6 months (12.1 [3.9-37.0], P<.001), and a higher Sequential Organ Failure Assessment score (for each increase by 1 in score, 1.3 [1.2-1.4], P<.001). CONCLUSION: Risk factors for death among US patients with severe influenza during the 2013-2014 season, when influenza A (H1N1) pdm09 was the predominant circulating strain type, shifted in the first postpandemic season in which it predominated toward those of a more typical epidemic influenza season.

Unexpected inverse correlation between Native American ancestry and Asian American variants of HPV16 in admixed Colombian cervical cancer cases.

BACKGROUND: European (E) variants of HPV 16 are evenly distributed among world regions, meanwhile Non-European variants such as European-Asian (EAs), Asian American (AA) and African (Af) are mostly confined to Eastern Asia, The Americas and African regions respectively. Several studies have shown that genetic variation of HPV 16 is associated with the risk of cervical cancer, which also seems to be dependent on the population. This relationship between ethnicity and variants have led to the suggestion that there is co-evolution of variants with humankind. Our aim was to evaluate the relationship between the individual ancestry proportion and infection with HPV 16 variants in cervical cancer. METHODS: We examined the association between ancestry and HPV 16 variants in samples of 82 cervical cancer cases from different regions of Colombia. Individual ancestry proportions (European, African and Native American) were estimated by genotyping 106 ancestry informative markers. Variants were identified by PCR amplification of the E6 gene, followed by reverse line blot hybridization (RLB) with variants specific probes. RESULTS: Overall European (E) and Asian American (AA) variants frequency was 66.5% and 33.5% respectively. Similar distribution was observed in cases with higher proportions of European or African ancestry. A higher Native American ancestry was significantly associated with higher frequency of E variants (median ancestry>23.6%, Age and place of birth adjusted OR: 3.55, 95% CI: 1.26-10.03, p=0.01). Even further, an inverse geographic correlation between Native American ancestry and frequency of infections with AA variants was observed (ρ=-0.825, p=0.008). Regions with higher proportion of Native American ancestry had a lower frequency of AA variants of HPV 16. CONCLUSIONS: This study suggests replacement of AA variants by E variants of human papillomavirus 16 in cervical cancer cases with high Native American ancestry.

Immunosuppression in cervical cancer with special reference to arginase activity.

INTRODUCTION: Cervical cancer is characterized by an immunosuppressive microenvironment and a Th2-type cytokine profile. Expression of arginase (ASE), the enzyme that converts L-arginine into L-ornithine and urea, is stimulated by Th2-type cytokines. OBJECTIVE: To assess the association of ASE activity and L-Arg metabolism products with cervical cancer. METHODS: Sera of 87 and 41 women with histologically confirmed by colposcopy-directed biopsy SCC and CIN3 respectively and 79 with normal cytology or Low-Grade Squamous Intraepithelial Lesion (LSIL), were evaluated. Cytokines were measured using Milliplex Human cytokine/chemokine kit. Arginase (ASE) activity was determined using an enzymatic assay. Levels of L-arginine, L-ornithine, putrescine and spermine were determined by HPLC. RESULTS: Significantly higher levels of ASE activity were observed in women with CIN3 (age-adjusted OR: 24.3; 95%CI: 3.82-155) and SCC (AOR: 9.8; 95%CI: 2.34-40.8). As expected, possibly due to high levels of ASE activity, higher levels of l-Arg were negatively associated with CIN3 (AOR: 0.03; 95%CI: 0.004-0.19) and SSC (AOR: 0.06; 95%CI: 0.02-0.24). Consistent with the role of ASE in the conversion of L-arginine to L-ornithine and polyamine production therefrom, women with cervical cancer had higher levels of spermine and putrescine. A correlation analysis revealed a significant albeit weak relationship between high levels of IL-10 and high levels of ASE (Pearson r=0.32, p-value=0.003) in women with cervical cancer. CONCLUSION: This study indicates that ASE activity and L-Arg degradation mechanisms of immunosuppression are present in cervical cancer. The results foster research in the design of possible strategies to inhibit ASE activity for therapy of cervical cancer.

Tratamiento del síndrome de robo del acceso vascular mediante interposición yuxtaanastomótica de un segmento protésico / Treatment of vascular access-related steal syndrome by means of juxta-anastomotic vein interposition of a prosthetic graft segment

Objetivos: El síndrome de robo es una complicación grave del acceso vascular. Nuestro objetivo es presentar los resultados iniciales de un tratamiento simple y eficaz: la interposición de un segmento protésico en la vena yuxtaanastomótica. Métodos: Entre 2009 y 2012, 14 pacientes (57 % varones, edad media 71 años) con síndrome de robo severo por un acceso vascular nativo (grados II-IV), y tras un estudio clínico y ecográfico sistemático, y angiográfico selectivo, fueron tratados mediante la interposición de un segmento de prótesis tubular, politetrafluoroetileno (PTFE) de 6 mm de diámetro en la vena yuxtaanastomótica, más reparación selectiva de estenosis arterial mediante parche (2 casos) o ligadura de colaterales venosas no útiles (8 casos). Se utilizó anestesia local o regional y un régimen ambulatorio en todos los casos. Resultados: El éxito técnico fue del 100 %. El estudio ecográfico pre y posoperatorio mostró una reducción del flujo posoperatorio del acceso del 39 % y un aumento del flujo arterial radial del 477 %. Los síntomas isquémicos se resolvieron en 12 pacientes (86 %); los otros dos requirieron procedimientos adicionales por síntomas isquémicos persistentes. Ocurrió una ruptura venosa posoperatoria, que requirió una ligadura definitiva. Ningún caso sufrió amputaciones ni hubo pérdidas ni trombosis del acceso en el seguimiento. Las permeabilidades primaria y primaria asistida libres de nuevos síntomas isquémicos fueron del 78 % y del 78 % a los 12 meses, y del 62 % y del 78 % a los 24 meses. Conclusiones: La interposición de un segmento protésico yuxtaanastomótico es una técnica sencilla, rápida y eficaz en el tratamiento del síndrome de robo vascular, con resultados prometedores a dos años de seguimiento (AU)

Objective: Steal syndrome is a severe complication of vascular access. Our aim is to present the initial results of a simple and effective treatment: the interposition of a prosthetic segment in the juxta-anastomotic vein. Method: Between 2009 and 2012, 14 patients (57 % male, average age 71) with severe steal syndrome due to vascular access (stages II-IV), following a clinical and systematic echographic study and a selective angiographic study, were treated through the interposition of a 6 mm segment of PTFE in the juxta-anastomotic vein, in addition to selective patch repair of arterial stenosis (2 cases) or ligature of useless venous collaterals (8 cases). Local or regional anaesthesia was used and outpatient care was given in all cases. Results: There was 100 % technical success. The pre- and post-operative echographical study showed a reduction of post-operative access flow by 39 % and an increase of radial artery flow by 477 %. Ischaemic symptoms were resolved in 12 patients (86 %); the other two patients required additional procedures due to persistent ischaemic symptoms. There was a post-operative venous rupture, which required a definitive ligation. No patient suffered amputations, nor were there losses or access thrombosis during the follow-up. The primary and primary-assisted patencies free of new ischemic symptoms were 78 % and 78 % at 12 months, and 62 % and 78 % at 24 months. Conclusions: The interposition of a prosthetic segment in the juxta-anastomotic vein is a simple, quick and effective technique in the treatment of vascular steal syndrome, with promising results at the 2 year follow-up (AU)

Treatment of vascular access-related steal syndrome by means of juxta-anastomotic vein interposition of a prosthetic graft segment.

OBJECTIVE: Steal syndrome is a severe complication of vascular access. Our aim is to present the initial results of a simple and effective treatment: the interposition of a prosthetic segment in the juxta-anastomotic vein. METHOD: Between 2009 and 2012, 14 patients (57 % male, average age 71) with severe steal syndrome due to vascular access (stages II-IV), following a clinical and systematic echographic study and a selective angiographic study, were treated through the interposition of a 6 mm segment of PTFE in the juxta-anastomotic vein, in addition to selective patch repair of arterial stenosis (2 cases) or ligature of useless venous collaterals (8 cases). Local or regional anaesthesia was used and outpatient care was given in all cases. RESULTS: There was 100 % technical success. The pre- and post-operative echographical study showed a reduction of post-operative access flow by 39 % and an increase of radial artery flow by 477 %. Ischaemic symptoms were resolved in 12 patients (86 %); the other two patients required additional procedures due to persistent ischaemic symptoms. There was a post-operative venous rupture, which required a definitive ligation. No patient suffered amputations, nor were there losses or access thrombosis during the follow-up. The primary and primary-assisted patencies free of new ischemic symptoms were 78 % and 78 % at 12 months, and 62 % and 78 % at 24 months. CONCLUSIONS: The interposition of a prosthetic segment in the juxta-anastomotic vein is a simple, quick and effective technique in the treatment of vascular steal syndrome, with promising results at the 2 year follow-up.

Emerging therapies for Clostridium difficile infection - focus on fidaxomicin.

The epidemiology of Clostridium difficile infections (CDI) has evolved during the last decades, with an increase in the reported incidence, severity of cases, and rate of mortality and relapses. These increases have primarily affected some special populations including the elderly, patients requiring concomitant antibiotic therapy, patients with renal failure, and patients with cancer. Until recently, the treatment of CDI was limited to either metronidazole or vancomycin. New therapeutic options have emerged to address the shortcomings of current antibiotic therapy. Fidaxomicin stands out as the first-in-class oral macrocyclic antibiotic with targeted activity against C. difficile and minimal collateral damage on the normal colonic flora. Fidaxomicin has demonstrated performance not inferior to what is considered the "gold standard" available therapy for CDI, vancomycin, in two separate Phase III clinical trials, but with significant advantages, including fewer recurrences and higher rates of sustained clinical cures. Fidaxomicin constitutes an important development in targeted antibiotic therapy for CDI and must be considered as a first-line agent for patients with risk factors known to portend relapse and severe infection.

Cumulative clinical experience from over a decade of use of levofloxacin in urinary tract infections: critical appraisal and role in therapy.

The treatment of urinary tract infections (UTIs) continues to evolve as common uropathogens increasingly become resistant to previously active antimicrobial agents. In addition, bacterial isolates, which were once considered to be either colonizers or contaminants, have emerged as true pathogens, likely related to the more complex array of settings where health care is now delivered. Even though the reliability of many antimicrobial agents has become less predictable, the fluoroquinolone group of agents has remained a frequent, if not the most often prescribed, antimicrobial therapy for almost all types of UTIs. Levofloxacin has taken its position at the top of the list as one of the most regularly administered fluoroquinolone agents given to patients with a suspected or proven UTI. The authors review the clinical experience of the use of levofloxacin over the past decade and suggest that the use of levofloxacin for the treatment of UTIs, although still fairly dependable, is perhaps not the best use of this important antimicrobial agent.

Mycobacterial prosthetic valve endocarditis.

Prosthetic valve endocarditis (PVE) due to mycobacteria is a rare but frequently fatal complication that may occur early after the surgical procedure, or even years later. Infection has been described with both mechanical and biologic valvular prosthesis. The most commonly implicated mycobacterial species belong to the rapid-grower group (M. chelonei, M. fortuitum, and M. abscessus) of nontuberculous mycobacteria (NTM). The source of infection in this context is thought to be nosocomial, likely related to preoperative or intraoperative contamination of the prosthesis by contact with aqueous solutions containing the organisms. These infections are difficult to diagnose because blood cultures are often negative. Clinically, it is important to recognize the possibility of NTM-PVE in the differential diagnosis of culture-negative patients who develop signs and symptoms of endocarditis, whether they present early or late in onset after the surgical procedure. These patients should be treated with surgical removal of the infected valve, followed by adequate antimicrobial therapy based on the susceptibility of the species isolated from the valve or perivalvular tissue culture. In a significant number of patients, however, an unstable hemodynamic condition ensues, precluding surgical intervention, and therefore leading to a high mortality rate.

Metodología para seleccionar zonas de intervención con cultivos biofortificados / Methodology for selecting areas for biofortified crop intervention

OBJETIVO: Identificar zonas geográficas de América Latina y el Caribe para la biofortificación de cultivos básicos como frijol, maíz, arroz, yuca y batata, contribuyendo así a reducir las deficiencias nutricionales en la Región. MÉTODO: Se generó un sistema de información geográfica (SIG) que incluyó registros sobre riesgos nutricionales, producción de cultivos, consumos alimenticios, y datos demográficos y socioeconómicos para 11 países de la Región. Se realizaron cuatro estudios de caso (en Guatemala, México, Bolivia y Colombia) basados en un análisis exploratorio y descriptivo de mapas temáticos, y su superposición y comparación para buscar patrones espaciales e identificar zonas candidatas de intervención. RESULTADOS: En Guatemala, las mayores tasas de riesgos nutricionales, producción de frijol y densidad poblacional coincidieron en las regiones Nororiental y Suroriental. En México, la distribución espacial de los niveles más altos de riesgos nutricionales, pobreza y producción de maíz se concentraron en los municipios del centro y sur. En Bolivia la producción de frijol tendió a situarse en el este del país, y el riesgo nutricional en el oeste. En Colombia, tanto los riesgos nutricionales como la producción de yuca mostraron una gran dispersión geográfica. CONCLUSIONES: Para Guatemala se propone la biofortificación con hierro del frijol en el sur de la región Nororiental y en la Suroriental, en México, la biofortificación del maíz con aminoácidos en los municipios productores del centro y sur del país; para Bolivia, una intervención con frijol biofortificado con hierro y zinc en zonas productoras de Santa Cruz, Chuquisaca y Tarija; y en Colombia, la biofortificación de yuca con β-caroteno en los departamentos de Córdoba y Cundinamarca.

OBJECTIVE: To identify geographical areas in Latin America and the Caribbean where biofortification of staple crops, such as beans, corn, rice, cassava, and sweet potatoes, might help reduce nutritional deficiencies in the Region. METHODS: A geographic information system (GIS) was produced with records on nutritional risks, crop production, food consumption, and demographic and socioeconomic data, for 11 countries in the Region. Four case studies were conducted (in Bolivia, Colombia, Guatemala, and Mexico) using exploratory and descriptive analysis of thematic maps that were superimposed and compared to reveal overlapping and spatial patterns, thereby identifying areas suited to intervention. RESULTS: In Guatemala, the highest rates of nutritional risk, bean production, and population density overlapped in the northeast and southeast areas. In Mexico, spatial distribution of the highest risk levels for nutrition, poverty, and corn production were concentrated in the central and southern municipalities. In Bolivia, bean production tended to be in the eastern part of the country, and nutritional risk, in the west. In Colombia, both nutritional risk and cassava production showed wide geographic dispersion. CONCLUSIONS: For Guatemala, we propose iron biofortification of beans in the southern parts of the northeast and southeast; for Mexico, amino-acid biofortification of corn in the central and southern municipalities that produce it; for Bolivia, iron and zinc biofortification of beans in the bean-producing areas of Santa Cruz, Chuquisaca, and Tarija; and for Colombia, β-carotene biofortification of cassava in the Cordoba and Cundinamarca departments.

[Methodology for selecting areas for biofortified crop intervention]. / Metodología para seleccionar zonas de intervención con cultivos biofortificados.

OBJECTIVE: To identify geographical areas in Latin America and the Caribbean where biofortification of staple crops, such as beans, corn, rice, cassava, and sweet potatoes, might help reduce nutritional deficiencies in the Region. METHODS: A geographic information system (GIS) was produced with records on nutritional risks, crop production, food consumption, and demographic and socioeconomic data, for 11 countries in the Region. Four case studies were conducted (in Bolivia, Colombia, Guatemala, and Mexico) using exploratory and descriptive analysis of thematic maps that were superimposed and compared to reveal overlapping and spatial patterns, thereby identifying areas suited to intervention. RESULTS: In Guatemala, the highest rates of nutritional risk, bean production, and population density overlapped in the northeast and southeast areas. In Mexico, spatial distribution of the highest risk levels for nutrition, poverty, and corn production were concentrated in the central and southern municipalities. In Bolivia, bean production tended to be in the eastern part of the country, and nutritional risk, in the west. In Colombia, both nutritional risk and cassava production showed wide geographic dispersion. CONCLUSIONS: For Guatemala, we propose iron biofortification of beans in the southern parts of the northeast and southeast; for Mexico, amino-acid biofortification of corn in the central and southern municipalities that produce it; for Bolivia, iron and zinc biofortification of beans in the bean-producing areas of Santa Cruz, Chuquisaca, and Tarija; and for Colombia, beta-carotene biofortification of cassava in the Cordoba and Cundinamarca departments.