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1.  Germinoma in the Internal Auditory Canal Mimicking a Vestibular Schwannoma 
Case Reports in Otolaryngology  2014;2014:794158.
The appearance of a primary germinoma in the central nervous system but not on or near the midline or within the brain is exceptional. It may occur at any age; however, it is rare in patients over 50 years old. Only a handful of cases of germinomas located in the cerebellopontine angle were presented, but to our knowledge, there has been no description of an isolated germinoma in the internal auditory canal. We report a case of germinoma in the internal auditory canal in a 51-year-old man simulating the clinical and radiological characteristics of a vestibular schwannoma.
PMCID: PMC3914568  PMID: 24551468
2.  Vertigo as the First Sign of Chronic Myeloid Leukemia: A Case Report and Literature Review 
Case Reports in Otolaryngology  2013;2013:505636.
Acute vestibular deficit as the first sign of leukemia is extremely rare. The literature shows some cases of sudden hearing loss accompanied by instability and associated with hyperviscosity syndrome. We present the case of a patient who presents a harmonic vestibular deficit of the right ear. The complementary studies revealed an abnormally high level of leukocytes. A peripheral blood cytogenetic analysis is performed due to a high suspicion of leukemia, and the results show BCR/ABL fusion gene with a cut point in the M-BCR region, which confirms the diagnosis of chronic myeloid leukemia. In this case we detail the importance of taking hematological disorders into consideration in the differential diagnosis of patients with otoneurological symptoms, and we also review the etiopathogenic mechanisms, symptoms, diagnosis, and therapeutic options for chronic myeloid leukemia with sudden hearing loss and vertigo.
PMCID: PMC3583057  PMID: 23476855
3.  Expanding the Use of a Fluorogenic Method to Determine Activity and Mode of Action of Bacillus thuringiensis Bacteriocins Against Gram-Positive and Gram-Negative Bacteria 
The Scientific World Journal  2012;2012:503269.
Previously we described a rapid fluorogenic method to measure the activity of five bacteriocins produced by Mexican strains of Bacillus thuringiensis against B. cereus 183. Here we standardize this method to efficiently determine the activity of bacteriocins against both Gram-positive and Gram-negative bacteria. It was determined that the crucial parameter required to obtain reproducible results was the number of cells used in the assay, that is, ~4 × 108 cell/mL and ~7 × 108 cell/mL, respectively, for target Gram-positive and Gram-negative bacteria. Comparative analyses of the fluorogenic and traditional well-diffusion assays showed correlation coefficients of 0.88 to 0.99 and 0.83 to 0.99, respectively, for Gram-positive and Gram-negative bacteria. The fluorogenic method demonstrated that the five bacteriocins of B. thuringiensis have bacteriolytic and bacteriostatic activities against all microorganisms tested, including clinically significant bacteria such as Listeria monocytogenes, Proteus vulgaris, and Shigella flexneri reported previously to be resistant to the antimicrobials as determined using the well-diffusion protocol. These results demonstrate that the fluorogenic assay is a more sensitive, reliable, and rapid method when compared with the well-diffusion method and can easily be adapted in screening protocols for bacteriocin production by other microorganisms.
PMCID: PMC3415160  PMID: 22919330
4.  An unsupervised strategy for biomedical image segmentation 
Many segmentation techniques have been published, and some of them have been widely used in different application problems. Most of these segmentation techniques have been motivated by specific application purposes. Unsupervised methods, which do not assume any prior scene knowledge can be learned to help the segmentation process, and are obviously more challenging than the supervised ones. In this paper, we present an unsupervised strategy for biomedical image segmentation using an algorithm based on recursively applying mean shift filtering, where entropy is used as a stopping criterion. This strategy is proven with many real images, and a comparison is carried out with manual segmentation. With the proposed strategy, errors less than 20% for false positives and 0% for false negatives are obtained.
PMCID: PMC3170003  PMID: 21918628
segmentation; mean shift; unsupervised segmentation; entropy

Results 1-4 (4)