Publications by authors named "NARVAEZ V"

Hemodialysis access-induced distal ischemia () is an uncommon, yet potentially devastating, complication of hemodialysis access surgery. Management of HAIDI depends on the access' volume flow and may involve banding, proximalization of arterial inflow, revision using distal inflow, distal revascularization interval ligation, or access ligation. Various adjunctive techniques have been used to confirm improved distal arterial flow intraoperatively.

View Article and Find Full Text PDF

Objective: to determine the levels of empathy in professional nurses of a high-complexity hospital, to relate age to empathy (and each one of its dimensions), and to establish if there are differences between these levels according to the type of working schedules.

Method: comparative, correlational and cross-sectional design. The sample used (n=271) constituted 40.

View Article and Find Full Text PDF

Objective: To describe the development of an artificial placenta (AP) system in sheep with learning curve and main bottlenecks to allow survival up to one week.

Methods: A total of 28 fetal sheep were transferred to an AP system at 110-115 days of gestation. The survival goal in the AP system was increased progressively in three consecutive study groups: 1-3 h (n = 8), 4-24 h (n = 10) and 48-168 h (n = 10).

View Article and Find Full Text PDF

Background: During the COVID-19 pandemic, cardiovascular patients were found to be presenting to hospitals with myocardial infarctions and cerebrovascular accidents at progressed disease states. We noticed a parallel in acute limb ischemia (ALI) patients presenting during Massachusetts' COVID-19 State of Emergency declaration. We question whether patients developed a hesitancy to seek medical attention at hospitals due to fear of COVID-19.

View Article and Find Full Text PDF

Background: Several trauma studies have shown that a "flat" inferior vena cava (IVC) is associated with poor clinical outcomes, including hypovolemic shock, major bleeding, transfusions and mortality. These studies utilize IVC measurements on computed tomography (CT) scans, and rarely include emergency general surgery patients. We examine the association between IVC flatness and clinical outcomes in a series of patients with perforated viscus.

View Article and Find Full Text PDF

Objective: To compare individuals with eating disorders (EDs) to healthy controls (HCs) to assess for differences in direct engagement in the eating process.

Method: Participants (n=58) were asked to eat an orange slice. To assess the degree of direct engagement with the eating process, participants were asked to write down 10 thoughts about the experience of eating the orange slice.

View Article and Find Full Text PDF

Platelet-activating factor (PAF) acting via its receptor (PAFR) is implicated in the pathogenesis of persistent pulmonary hypertension of the newborn (PPHN). Effects of long-term oxygen therapy on newborn lung are not well understood; therefore, we studied the effect of oxygen tension on ovine newborn pulmonary artery smooth muscle cells (NBPASMC). Our global hypothesis is that PPHN results from failure of newborn lamb pulmonary system to downregulate PAFR activity or to upregulate vasodilatory cyclic nucleotides (Cnucs) activity.

View Article and Find Full Text PDF

Quadrilateral space syndrome (QSS) is a rare nerve entrapment disorder that occurs when the axillary nerve and posterior circumflex humeral artery (PCHA) become compressed in the quadrilateral space. QSS presents as vague posterolateral shoulder pain that is exacerbated upon the abduction and external rotation of the shoulder. Diagnosis of QSS is difficult because of the vague presentation of QSS.

View Article and Find Full Text PDF

Pyrimethamine is an antimalarial drug that has also been used successfully to treat autoimmune diseases such as lymphoproliferative syndrome. In this work, the effect of pyrimethamine (PYR) on the production of free radicals in malaria-infected mice was studied to better understand the drug's immunomodulatory properties. BALB/c and CBA/Ca mice were infected with Plasmodium yoelii 17XL.

View Article and Find Full Text PDF

Chloroquine (CLQ) and Pyrimethamine (PYR) are used for the treatment of malaria and some autoimmune diseases; although their mechanism of action is only partially understood, their therapeutic effectiveness in the second case has been attributed to their ability to increase apoptosis of T lymphocytes. In view of the potential for immunomodulation during malaria chemotherapy, we investigated the effects of CLQ and PYR treatment on lymphocyte apoptosis and cytokine expression during infection with blood-stage Plasmodium. This work shows that infection of BALB/c mice with Plasmodium yoelii 17XL (Py17XL) reduced apoptosis in spleen cells but when infected mice were treated with CLQ, apoptosis of B and T lymphocytes increased significantly via a Fas-mRNA expression independent mechanism associated with downregulation of Bcl-2 expression, whereas treatment with PYR increased apoptosis to a lesser extent and only in B lymphocytes.

View Article and Find Full Text PDF

Vertebrate limb development is a well-studied model of apoptosis; however, little is known about the intracellular molecules involved in activating the cell death machinery. We have shown that high levels of reactive oxygen species (ROS) are present in the interdigital 'necrotic' tissue of mouse autopod, and that antioxidants can reduce cell death. Here, we determined the expression pattern of several antioxidant enzymes in order to establish their role in defining the areas with high ROS levels.

View Article and Find Full Text PDF

The involvement of reactive oxygen species (ROS) in neuronal death has been determined in culture, and in association with several neurodegenerative disorders. We examined whether ROS participate in the cell death observed during spinal cord development. We found that the general pattern of high ROS levels, gene expression for some antioxidant enzymes, and motoneuron death correlated positively along spinal cord development.

View Article and Find Full Text PDF

The Y chromosome gene Sry encodes a transcription factor required to initiate testis development. The related autosomal gene Sox9 is up-regulated shortly after the onset of Sry transcription and is thought essential for the differentiation of Sertoli cells. The lineage that gives rise to Sertoli cells has its origins within the coelomic epithelium (CE) of the genital ridge, but from cells also able to give rise to an interstitial cell type.

View Article and Find Full Text PDF

The nuclear hormone receptor DAX1 has been implicated in mammalian gonad development and sex determination. The expression of the gene in the gonad follows a dynamic pattern in time and place in the embryo and the adult. We have undertaken the first in vivo study of the regulation of Dax1 expression.

View Article and Find Full Text PDF

DAX1, which encodes an unusual member of the nuclear hormone-receptor superfamily, is a gene that may be responsible for a sex-reversal syndrome in humans, referred to as dosage-sensitive sex reversal, in which XY individuals carrying duplications of Xp21, part of the small arm of the X chromosome, develop as females. XY mice carrying extra copies of mouse Dax1 as a transgene show delayed testis development when the gene is expressed at high levels, but do not normally show sex reversal. Complete sex reversal occurs, however, when the transgene is tested against weak alleles of the sex-determining Y-chromosome gene Sry.

View Article and Find Full Text PDF