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Biomedical subjects

J Zapata

Publications and source records attributed to J Zapata.

10 recordsLinked to original sources
PubMed2006

Diagenesis, not biogenesis: Two late Roman skeletal examples.

Bone element analysis of two Late Roman populations from coastal south-eastern Spain suggests significant diagenesis. Trace element levels, in particular elevated Sr, Pb, Al, Mn, and the Ca/P ratio indicate post-mortem changes in the composition of the bones, preventing use of the data for dietary reconstructions, as well as for the investigation of the different individuals' health conditions, or of links between diet, health and skeletal indicators of growth stress. Such diagenetic biases are more widespread than usually recognized; paleodietary and paleoenvironmental inferences derived from the chemistry of archaeological bones need to be critically assessed.

Adult↗
PubMed2001

alpha 4 Integrins and sialyl Lewis x modulation in chronic Chagas disease: further evidence of persistent immune activation.

We have previously shown that titers of soluble platelet selectin (s-P-selectin) and soluble vascular cell adhesion molecule-1 (s-VCAM-1) were increased in sera of patients with chronic Trypanosoma cruzi infection. In this study, we analyzed the expression of CD49d-integrins, that bind to VCAM-1, and sialyl Lewis x (SLe(x)), which binds selectins, in peripheral blood lymphocytes of 27 patients with Chagas' disease at different levels of disease severity. Patients with a mild form of Chagas' disease showed a lower number of CD49d(+) cells, in comparison with those with severe chronic cardiopathy. Decreased levels of CD49d(+) cells were detected in CD3(-) cell populations. Conversely, SLe(x) expression was found to be decreased in patients with severe Chagas' disease. Levels of soluble platelet endothelial cell adhesion molecule-1 (s-PECAM-1) were significantly increased in the plasma of patients with severe Chagas' disease while unaltered levels of MCP-1 were recorded. These data show that VCAM-1 and P-Selectin ligands are differentially expressed during the chronic phase of the Trypanosoma cruzi infection. These findings also reinforce a role of the P-selectin/SLe(x) adhesion pathway rather than very late antigen-4 (VLA-4)/VCAM-1, in the pathogenesis of Chagas' disease.

Adult↗
PubMed2000

An active contour model algorithm for tracking endocardiac boundaries in echocardiographic sequences.

The use of active contour models to track the boundaries of anatomic structures in medical images is a technique that has attracted a great number of efforts during the last decade. Segmentation techniques based in deformable active contours were proposed first by Kass et al. Because of the problems appearing using these models, some solutions have been introduced, such as balloon force or Gradient Vector Flow force (GVF), derived from the Gradient Vector Flow vectorial field. Results obtained with these forces in the tracking endocardiac task in echocardiographic sequences were not adequate. We have designed a new external force called hybrid force, which, by combining both forces, joins the main features of each one.

Algorithms↗
PubMed1999

TRAF family proteins interact with the common neurotrophin receptor and modulate apoptosis induction.

The common neurotrophin receptor, p75(NTR), has been shown to signal in the absence of Trk tyrosine kinase receptors, including induction of neural apoptosis and activation of NF-kappaB. However, the mechanisms by which p75(NTR) initiates these intracellular signal transduction pathways are unknown. Here we report interactions between p75(NTR) and the six members of TRAF (tumor necrosis factor receptor-associated factors) family proteins. The binding of different TRAF proteins to p75(NTR) was mapped to distinct regions in p75(NTR). Furthermore, TRAF4 interacted with dimeric p75(NTR), whereas TRAF2 interacted preferentially with monomeric p75(NTR). TRAF2-p75(NTR), TRAF4-p75(NTR), and TRAF6-p75(NTR) interactions modulated p75(NTR)-induced cell death and NF-kappaB activation with contrasting effects. Coexpression of TRAF2 with p75(NTR) enhanced cell death, whereas coexpression of TRAF6 was cytoprotective. Furthermore, overexpression of TRAF4 abrogated the ability of dimerization to prevent the induction of apoptosis normally mediated by monomeric p75(NTR). TRAF4 also inhibited the NF-kappaB response, whereas TRAF2 and TRAF6 enhanced p75(NTR)-induced NF-kappaB activation. These results demonstrate that TRAF family proteins interact with p75(NTR) and differentially modulate its NF-kappaB activation and cell death induction.

Apoptosis↗
PubMed1999

The use of folk healing and healers by six Latinos living in New England: a preliminary study.

The purpose of this qualitative study is to describe Latinos' use of folk medicine and the values associated with it in the context of mainstream health care. The research questions focused on the meaning of folk medicine in the Latino culture and how participants made decisions regarding the use of folk medicine or modern biomedicine. Interviews were conducted with six Latinos living in a New England city who had used folk medicine. Three themes were identified: being sick, healers and healing, and faith and believing. The participants in this study valued their cultural folk medicine and folk healers. However, none relied exclusively on folk medicine. All used mainstream health care providers for specific purposes. A major reason for not using mainstream health care providers more frequently was the perceived lack of holistic care and the use of medicines that are not natural.

Adult↗
PubMed1997

Solitary ileocolic arteriovenous malformation: spongostan and silk therapeutic embolisation.

A debilitated patient with liver cirrhosis and poor haemostasis had a severe lower gastrointestinal haemorrhage. A superior mesenteric arteriogram revealed an early persistent and promiment draining vein in the ileocolic artery. Two fragments of Spongostan and silk were used to embolise the bleeding artery and the haemorhage ceased immediately. No infarction of the embolised area was observed and the bleeding was controlled.

Arteriovenous Malformations↗
PubMed1973

The formation, isolation, and biological activity of a cytokinin 7-glucoside.

The cytokinin, 6-benzylaminopurine, is converted to its 7-glucoside in intact seedlings, organ slices, and tissue cultures from several plants. The ribonucleoside and 5'-ribonucleotide appear transiently, and the general metabolic sequence seems to be nearly identical in the four plant species thus far studied. The glucoside persists for long periods in plant tissues, while all other forms of the cytokinin are rapidly metabolized and disappear within a few hours. A procedure for the isolation in pure form of the glucoside is described.

Journal Article↗
PubMedDate not supplied

[Cerebral infarction due to spontaneous dissection of the left common carotid artery].

Spontaneous dissection of the extracranial cervicocephalic arteries occurs most often in the internal carotid artery or vertebral artery. Spontaneous dissection of a common carotid artery is rare, with only nine cases having been reported. A 43-year-old man was hospitalized for sudden onset of motor aphasia and right arm weakness due to spontaneous dissection of a left common carotid artery; no sign of aortic disection was evident on aortogram. The most common causes of dissection of the common carotid artery are the extension of an aortic dissection and the complication in an angiogram with direct puncture; spontaneous dissection being very rare. We review the previous literature on this topic.

Adult↗