Dynamics of serum immunoglobulin G and total protein concentrations in dairy calves during the first 2 weeks of life.

The aim of the present study was to describe the dynamics of serum IgG (determined with radial immunodiffusion) and total protein (TP; determined with refractometry) concentrations during the first 16 d of life. Secondary objectives were to evaluate the transfer of passive immunity (TPI) classification at d 1 of life as a conditional factor for the aforementioned dynamics, and to describe over time changes on calves' TPI classification. At a commercial raising operation, 36 calves (19 Holstein, 17 Jersey) were sampled immediately after arrival (d 1) and at d 4, 8, 12 and 16 of life, for serum IgG and TP concentration, and hematocrit determination (HCT). Transfer of passive immunity was categorized based on serum IgG (IgG-Poor: IgG <18 g/L; IgG-Good: IgG 18 to <25 g/L; IgG-Excellent: IgG ≥25 g/L) and TP concentrations (TP-Poor: <5.8 g/dL; TP-Good: 5.8 to <6.2 g/dL; TP-Excellent: ≥6.2 g/dL). Multiple linear regression was used to evaluate serum IgG and TP changes over time, considering the effects of time after birth, breed, HCT, and TPI classification at d 1 of life. At d 1, median serum IgG and TP concentrations were 29.9 g/L and 6.3 g/dL, respectively (interquartile ranges: 21.3-42.3 g/L and 5.6-6.7 g/dL, respectively). Dynamics of serum IgG and TP concentrations were conditional to TPI at d 1 of life. Serum IgG concentration declined over time for IgG-Excellent and IgG-Good calves (18.1 and 4.6 g/L, respectively), but remained constant for IgG-Poor calves. Serum TP concentration declined over time in the 3 TPI groups but it was more marked for TP-Excellent (27%) and TP-Good (19%) than for TP-Poor (14%) calves. At d 1, 83.3% of the calves were classified as IgG-Excellent or IgG-Good, whereas 77.8, 55.6, 41.7, and 58.3% of calves were classified within these categories at d 4, 8, 12, and 16 of life, respectively. Similarly, at d 1, 66.7% of calves were classified as TP-Excellent or TP-Good, whereas 47.2, 36.1, 25.0, and 2.8% were classified within these categories at d 4, 8, 12, and 16 of life, respectively. In summary, our results indicate that serum IgG and TP concentrations decline over 16 d of life, and the decline is associated with TPI classification at d 1 of life. Further studies are needed to determine the biological implications of serum IgG and TP decline after d 1 of life, and to elucidate the factors determining the different dynamics. Our results suggest that current thresholds for TPI classification should be interpreted carefully when the age of calves is unknown or outside the age range used to define those thresholds (>24 h to 7 d).

Retinopatía Diabética y Edema Macular Diabético en Población de Antioquia. Estudio transversal / Diabetic Retinopathy and Diabetic Macular Edema in a population of Antioquia. Cross-sectional study

Resumen Introducción: la diabetes mellitus (DM) es una epidemia mundial. La retinopatía diabética proliferativa (RDP), el edema macular diabético (EMD) y las complicaciones de la diabetes mellitus son las principales causas de discapacidad visual y ceguera en los adultos en la edad productiva. Aproximadamente, 1 de cada 3 personas con DM tiene retinopatía diabética (RD) y 1 de cada 10 tiene RDP o EMD. En el presente estudio se hace énfasis en esta última, siendo el primero con estas características en Colombia. Métodos: estudio transversal descriptivo donde se incluyeron 1.203 pacientes con diagnóstico de DM atendidos en la jornada "No más ciegos por Diabetes" del Hospital San Vicente Fundación de Medellín, en el 2017 y 2018. Se evaluó la presencia de RD y EMD clínico y sus características epidemiológicas en un análisis bivariado. Resultados: del total de pacientes con DM tamizados (1.203), el 5,4 % (65) tenían EMD; dentro de estos, el 7,7 % tenía DM tipo 1 y el 89,2% DM tipo 2. El 10,8 % tenía RDP, 73,8% tenía RD no proliferativo (RDNP). En un 93,8 % se hizo diagnósticos de novo de RD. La mediana del tiempo de la diabetes fue de 14 años, con un rango intercuartílico (RIQ) entre 7 y 19,5. La mediana de la hemoglobina glicosilada (HbA1C) fue de 8,3 % (RIQ: 7,1-11). De 65 pacientes con EMD, 28 (56 ojos de los 130 con EMD) fueron estudiados con tomografía de coherencia óptica (OCT) y al 85,7 % se le confirmó EMD. La mediana del grosor macular central fue de 249 micras (RIQ: 231-341) en los pacientes con EMD por OCT (n = 48 ojos). Conclusión: las complicaciones de la diabetes son más prevalentes en los pacientes con RD. La media del tiempo de aparición de EMD fue similar al tiempo de inicio de las complicaciones microvasculares de la diabetes reportada en la literatura, pero debe ser considerada en el contexto del control metabólico de los pacientes.

Summary Introduction: Diabetes Mellitus (DM) is a worldwide epidemic disease, with significant microvascular compromise. Proliferative diabetic retinopathy (PDR) as well as diabetic macular edema (DME) are currently two of the leading causes of visual impairment and blindness in adults of productive age. Approximately one in three people with DM have diabetic retinopathy (DR), and 1 in 10 have PDR or DME. This study emphasizes in the last one, being the first one with these characteristics in Colombia. Methods: This descriptive cross-sectional study includes 1203 patients diagnosed with DM evaluated in the "No more blindness due to diabetes" diabetic retinopathy-screening program of the San Vicente Foundation Hospital in Medellín between 2017 and 2018. The presence of DR and clinical macular edema with the epidemiologic variables were evaluated in a bivariate analysis. Results: From the total number of patients with DM screened (1203), 5,4% (65) had DME, 7,7% had DM type 1 and 89,2% had DM type 2, 10,8% had PDR and 73.8% had nonproliferative diabetic retinopathy NPDR. Most of the patients (93,8%) were diagnosed de novo with DR. The median illness time was 14 years with interquartile range (IQR) between 7 and 19,5. The median glycosylated hemoglobin (HbA1C) was 8.3% (IQR:7,1-11). Optical coherence tomography (OCT) study was done in 28 out of 65 patients with DME (56 out of 130 eyes with DME), in which 85.7% of patients were confirmed to have DME and the mean central macular thickness was 249 microns (IQR:231-341) (n=48 eyes). Conclusion: DM complications were more frequent in patients suffering from DR. The median onset time of DME symptoms was found to be similar to the time of microvascular complications appear; however, it should be considered along with the patient's metabolic control.

Reliability and Validity of Quantitative Video Analysis of Baseball Pitching Motion.

Video recordings are used to quantitatively analyze pitchers' techniques. However, reliability and validity of such analysis is unknown. The purpose of the study was to investigate the reliability and validity of joint and segment angles identified during a pitching motion using video analysis. Thirty high school baseball pitchers participated. The pitching motion was captured using 2 high-speed video cameras and a motion capture system. Two raters reviewed the videos to digitize the body segments to calculate 2-dimensional angles. The corresponding 3-dimensional angles were calculated from the motion capture data. Intrarater reliability, interrater reliability, and validity of the 2-dimensional angles were determined. The intrarater and interrater reliability of the 2-dimensional angles were high for most variables. The trunk contralateral flexion at maximum external rotation was the only variable with high validity. Trunk contralateral flexion at ball release, trunk forward flexion at foot contact and ball release, shoulder elevation angle at foot contact, and maximum shoulder external rotation had moderate validity. Two-dimensional angles at the shoulder, elbow, and trunk could be measured with high reliability. However, the angles are not necessarily anatomically correct, and thus use of quantitative video analysis should be limited to angles that can be measured with good validity.

An optimized enrichment technique for the isolation of Arthrobacter bacteriophage species from soil sample isolates.

Bacteriophage isolation from environmental samples has been performed for decades using principles set forth by pioneers in microbiology. The isolation of phages infecting Arthrobacter hosts has been limited, perhaps due to the low success rate of many previous isolation techniques, resulting in an underrepresented group of Arthrobacter phages available for study. The enrichment technique described here, unlike many others, uses a filtered extract free of contaminating bacteria as the base for indicator bacteria growth, Arthrobacter sp. KY3901, specifically. By first removing soil bacteria the target phages are not hindered by competition with native soil bacteria present in initial soil samples. This enrichment method has resulted in dozens of unique phages from several different soil types and even produced different types of phages from the same enriched soil sample isolate. The use of this procedure can be expanded to most nutrient rich aerobic media for the isolation of phages in a vast diversity of interesting host bacteria.