RESUMEN

Dialysis-related amyloidosis predominantly occurs in osteo-articular structures and dialysis-related amyloid (DRA) substances also deposit in extra-articular tissues. Clinical manifestations of DRA include odynophagia, gastrointestinal hemorrhage, intestinal obstruction, kidney stones, myocardial dysfunction, and subcutaneous tumors. The pathological characteristics of DRA in the heart of hemodialysis patients have rarely been reported. We report the case of a 73-year-old female with a history of cerebral palsy and end-stage renal disease status post two failed renal transplants who had been on hemodialysis for 30 years. The patient was admitted with the working diagnosis of pneumonia. An echocardiography showed markedly reduced biventricular function manifested by low blood pressure with systolic in the 70s and elevated pulmonary artery pressure of 45 mmHg, which did not respond to therapy. Following her demise, the autopsy revealed bilateral pulmonary edema and pleural effusions. There was cardiac amyloid deposition exclusively in the coronary arteries but not in the perimyocytic interstitium. Amyloids were also found in pulmonary and intrarenal arteries and the colon wall. Previous case reports showed that beta 2-microglobulin amyloid deposits in various visceral organs but less frequently in the atrial and/or the ventricular myocardium. In the present case, amyloids in the heart were present in the intramural coronary arteries causing myocardial ischemia and infarction, which was the immediate cause of death.

RESUMEN

Dialysis-related amyloidosis predominantly occurs in osteo-articular structures and dialysis-related amyloid (DRA) substances also deposit in extra-articular tissues. Clinical manifestations of DRA include odynophagia, gastrointestinal hemorrhage, intestinal obstruction, kidney stones, myocardial dysfunction, and subcutaneous tumors. The pathological characteristics of DRA in the heart of hemodialysis patients have rarely been reported. We report the case of a 73-year-old female with a history of cerebral palsy and end-stage renal disease status post two failed renal transplants who had been on hemodialysis for 30 years. The patient was admitted with the working diagnosis of pneumonia. An echocardiography showed markedly reduced biventricular function manifested by low blood pressure with systolic in the 70s and elevated pulmonary artery pressure of 45 mmHg, which did not respond to therapy. Following her demise, the autopsy revealed bilateral pulmonary edema and pleural effusions. There was cardiac amyloid deposition exclusively in the coronary arteries but not in the perimyocytic interstitium. Amyloids were also found in pulmonary and intrarenal arteries and the colon wall. Previous case reports showed that beta 2-microglobulin amyloid deposits in various visceral organs but less frequently in the atrial and/or the ventricular myocardium. In the present case, amyloids in the heart were present in the intramural coronary arteries causing myocardial ischemia and infarction, which was the immediate cause of death.

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RESUMEN

Borrelia chilensis strain VA1 is a recently described South American member of the Borrelia burgdorferi sensu lato complex from Chile. Whole-genome sequencing analysis determined its linear chromosome and plasmids lp54 and cp26, confirmed its membership in the Lyme borreliosis group, and will open new research avenues regarding its pathogenic potential.

RESUMEN

Fossil evidence documenting the evolutionary transition from theropod dinosaurs to birds indicates unambiguously that the digits of the wing of birds are digits 1, 2, and 3. However, some embryological evidence suggests that these digits are 2, 3, and 4. This apparent lack of correspondence has been described as the greatest challenge to the widely accepted theropod-bird link (Zhou 2004. Naturwissenschaften 91:455-471). Here we review the pertinent literature regarding the debate on the origin of birds and wing digital identity and the evidence in favor of a 1, 2, 3 identity of the wing digits. Recent molecular evidence shows that the expression of Hoxd12 and Hoxd13 in the developing wing supports the theropod-bird link. In the chicken foot and in the mouse hand and foot, digit 1 is the only digit to combine the expression of Hoxd13 with the absence of expression of Hoxd12. The same is observed in the anterior digit of the wing, suggesting it is a digit 1, as expected for a theropod. Nevertheless, Galis et al. (2005. J Exp Zool (Mol Dev Evol) in press), argue that Hoxd12 and Hoxd13 expression patterns in mutant limbs do not allow distinguishing the most anterior digit in the bird wing from digit 2. They also argue that constraints to the evolution of limb development support the 2, 3, 4 identity of the wing digits. However, the case put forward by Galis et al. is biased and flawed with regard to interpretation of mutant limbs, developmental mechanisms, stages observed, and the description of the evolutionary variation of limb development. Importantly, Galis et al. do not present evidence from wild-type limbs that counters the conclusions of Vargas and Fallon (2005. J Exp Zool (Mol Dev Evol) 304B(1):85-89), and fail to provide molecular evidence to specifically support the hypothesis that the wing digits are 2, 3, and 4. The expression of Hoxd12 and Hoxd13 in the developing wing is consistent with the hypothesis that birds are living dinosaurs; this view can lead to a greater understanding of the actual limits to the evolutionary variation of limb development.

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RESUMEN

Within developmental biology, the digits of the wing of birds are considered on embryological grounds to be digits 2, 3 and 4. In contrast, within paleontology, wing digits are named 1, 2, 3 as a result of phylogenetic analysis of fossil taxa indicating that birds descended from theropod dinosaurs that had lost digits 4 and 5. It has been argued that the development of the wing does not support the conclusion that birds are theropods, and that birds must have descended from ancestors that had lost digits 1 and 5. Here we use highly conserved gene expression patterns in the developing limbs of mouse and chicken, including the chicken talpid(2)mutant and polydactylous Silkie breed (Silkie mutant), to aid the assessment of digital identity in the wing. Digit 1 in developing limbs does not express Hoxd12, but expresses Hoxd13. All other digits express both Hoxd12and Hoxd13. We found this signature expression pattern identifies the anteriormost digit of the wing as digit 1, in accordance with the hypothesis these digits are 1, 2 and 3, as in theropod dinosaurs. Our evidence contradicts the long-standing argument that the development of the wing does not support the hypothesis that birds are living dinosaurs.

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