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Calixto Machado

Publications and source records attributed to Calixto Machado.

12 recordsLinked to original sources
PubMed2005

The first organ transplant from a brain-dead donor.

In 1968, publication of the Harvard committee's report concerning "irreversible coma" established a paradigm for defining death by neurologic criteria (brain death [BD]). Five years earlier, Dr. Guy Alexandre, a Belgian surgeon, had not only adopted closely similar diagnostic criteria for BD but also applied those criteria in performing the first organ transplant from a brain-dead donor--a procedure many of his colleagues considered ethically unacceptable. To put those events into present-day perspective, the author reviewed the proceedings of a Ciba Symposium held in London in 1966 at which Alexandre introduced his pioneering view, obtaining information and documents from Alexandre and others who attended that meeting. Comparing Alexandre's approach with the Harvard report and later advances helps in understanding how both defining death by brain criteria and transplanting organs from a brain-dead donor have become morally tolerable today.

Brain↗
PubMed2004

Assessing acute middle cerebral artery ischemic stroke by quantitative electric tomography.

This paper focuses on the application of quantitative electric tomography (qEEGT) to map changes in EEG generators for detection of early signs of ischemia in patients with acute middle cerebral artery stroke. Thirty-two patients were studied with the diagnosis of acute ischemic stroke of the left middle cerebral artery territory, within the first 24 hours of their clinical evolution. Variable Resolution Electrical Tomography was used for estimating EEG source generators. High resolution source Z-spectra and 3- dimensional images of Z values for all the sources at each frequency were obtained for all cases. To estimate statistically significant increments and decrements of brain electric activity within the frequency spectra, the t-Student vs. Zero test was performed. A significant increment of delta activity was observed on the affected vascular territory, and a more extensive increment of theta activity was detected. A significant alpha decrement was found in the parieto-occipital region of the affected cerebral hemisphere (left), and in the medial and posterior region of the right hemisphere. These findings suggest that qEEGT Z delta images are probably related to the main ischemic core within the affected arterial territory; penumbra, diaschisis, edema, might explain those observed theta and alpha abnormalities. It was concluded that qEEGT is useful for the detection of early signs of ischemia in acute ischemic stroke.

Acute Disease↗