Daniel Alfonso Botero-Rosas

Un nuevo método de procesamiento de imágenes para visualizar el patrón vascular del Cuello Uterino Humano

Cancer of the uterine cervix is a public health problem worldwide. Colposcopy is the commonest method employed to visualize human uterine cervix, and to diagnose uterine cervical cancer. When this structure is altered, colposcopy identifies and grades a number of characteristics of the lesions such as sizes, borders, shapes and vascular patterns. However, some drawbacks of the findings obtained by the classical colposcopic method are still unanswered. To improve the quality of the data obtained with colposcopy, selected images of human cervix were studied; further, a novel processing analysis was done using the top-hat and direct threshold methods. The analysis tree included selection of the image, elimination of frequency of oxyhemoglobin absorption, unsharped mask, treatment of specular highlights, filter approach and adjustment of intensity levels.We found that the top-hat method was superior that the direct threshold method to visualize the vascular pattern of human uterine cervix (93,1 % vs 85,1 %; p < 0,05). These findings were unrelated to the filter used. These results may help to increase the likelihood of detecting uterine cervical cancer of humans at earlier stages of the disease than known to date.

Una comparación de la respuesta autonómica en individuos hipertensos y no hipertensos para una maniobra ortostática

The aim of this paper is to analyze the autonomic behavior mediated by the baroreceptor response to an orthostatic maneuver (OM) in hypertensive and non-hypertensive subjects. The heart rate (HR) was obtained in 65 subjects (32 hypertensive and 33 non-hypertensive) using a frequency meter polar watch, before and after an OM (sudden standing). The R-R intervals were transformed into a heart rate, temporal series, and interpolation was applied due to a lack of heart rate periodicity. Sampling at 10Hz was performed, and a band-pass filter was applied followed by 1 Hz subsampling. The results showed an increase in sympathetic activity in the hypertensive group that did not occur in the non-hypertensive group after the OM (∆%=59.84%, P<0.01). For the parasympathetic results, decreases were found only in the hypertensive group and not in the non-hypertensive group after the orthostatic intervention (∆%= -43.4%, P<0.001). Increases in both groups were observed for the sympathovagal balance (hypertensive: ∆%= 45.63%, p=0.004; non-hypertensive: ∆%= 67.08%, p=0.013). The results showed increased sympathetic activity in contrast to a decreased parasympathetic response for hypertensive individuals after an OM.