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Biomedical subjects

Luis Ortega

Publications and source records attributed to Luis Ortega.

28 records · Page 2Linked to original sources
PubMed2003

Peripheral primitive neuroectodermal tumor after radiotherapy.

A 41-year-old man had a peripheral neuroectodermal tumor develop at the distal third of the fibula 4 years after radiotherapy for relapsed villonodular synovitis. This type of sarcoma usually is classified into the heterogeneic group of small round-cell bone tumors as a subdivision of Ewing's sarcomas. The immuno-staining positivity of the neoplastic cells for the neuron-specific enolase allowed the authors to make the diagnosis of a tumor with neuroectodermal origin. When the histologic study confirmed the diagnosis, the patient was treated with chemotherapy, surgical excision of the tumor, and adjuvant radiotherapy. Radiotherapy is thought to be involved in the genesis of osteogenic sarcomas as it has been shown in several reports, but there is no evidence in the literature of a peripheral neuroectodermal tumor developing after radiotherapy.

Adult↗
PubMed2003

The U.S.-Mexico Border Infectious Disease Surveillance project: establishing bi-national border surveillance.

In 1997, the Centers for Disease Control and Prevention, the Mexican Secretariat of Health, and border health officials began the development of the Border Infectious Disease Surveillance (BIDS) project, a surveillance system for infectious diseases along the U.S.-Mexico border. During a 3-year period, a binational team implemented an active, sentinel surveillance system for hepatitis and febrile exanthems at 13 clinical sites. The network developed surveillance protocols, trained nine surveillance coordinators, established serologic testing at four Mexican border laboratories, and created agreements for data sharing and notification of selected diseases and outbreaks. BIDS facilitated investigations of dengue fever in Texas-Tamaulipas and measles in California-Baja California. BIDS demonstrates that a binational effort with local, state, and federal participation can create a regional surveillance system that crosses an international border. Reducing administrative, infrastructure, and political barriers to cross-border public health collaboration will enhance the effectiveness of disease prevention projects such as BIDS.

Communicable Disease Control↗
PubMed2002

Atorvastatin reduces the expression of cyclooxygenase-2 in a rabbit model of atherosclerosis and in cultured vascular smooth muscle cells.

Inflammation is involved in the genesis and rupture of atherosclerotic plaques. We assessed the effect of atorvastatin (ATV) on the expression of cyclooxygenase-2 (COX-2) and other proinflammatory molecules in a rabbit model of atherosclerosis. Fourteen animals underwent injury of femoral arteries and 2 weeks of atherogenic diet. Afterwards, they were randomized to receive either 5 mg/kg per day of ATV (n=8) or no treatment (NT, n=6) during 4 weeks, and were finally killed. ATV reduced lipid levels, neointimal size (0.13 (0.03-0.29) mm(2) vs 0.65 (0.14-1.81) mm(2), P=0.005) and the percentage of neointimal area positive for macrophages (1% (0-3) vs 19% (5-32), P=0.001), COX-2 (32% (23-39) vs 60% (37-81) P=0.019), interleukin-8 (IL-8) (23% (3-63) vs 63% (25-88) P=0.015), and metalloproteinase-3 (19% (12-34) vs 42% (27-93), P=0.010), without significant differences in COX-1 expression (immunohistochemistry). In situ hybridization confirmed a decreased expression of COX-2 mRNA (22% (5-40) vs 43% (34-59) P=0.038). The activity of nuclear factor-kappaB, which controls many proinflammatory genes including COX-2, was reduced in atherosclerotic lesions (3538 (2663-5094) vs 8696 (5429-11312)) positive nuclei per mm(2), P=0.001) and circulating mononuclear cells (2966 vs 17130 arbitrary units). In cultured vascular smooth muscle cells, ATV reduced the expression of COX-2 mRNA induced by IL-1beta and TNF-alpha without affecting COX-1 expression. In conclusion, ATV, besides decreasing a number of inflammatory mediators in the atherosclerotic lesion, significantly downregulates COX-2 both in vivo and in vitro. These anti-inflammatory actions could partially account for the reduction of acute coronary events achieved by statins.

Animals↗
PubMed2002

Experimental lead nephropathy: treatment with calcium disodium ethylenediaminetetraacetate.

Chronic lead poisoning may cause hypertension, gout, and renal insufficiency. Most experimental poisoning studies have involved the use of high doses over short periods (ie, acute poisoning). Although chelating treatment leads to remission of acute lead nephropathy, its effects in the treatment of chronic poisoning are unclear. The aims of this study were to evaluate renal alterations produced during chronic lead poisoning and their progression when poisoning was over and to determine the efficiency of chelating treatment with calcium disodium ethylenediaminetetraacetate (EDTA). In this study, 56 male Wistar rats were administered lead in drinking water (500 ppm lead acetate) over 90 days. The control group consisted of 21 nonexposed rats. Seven rats from each group were killed on days 60 and 90. At the end of the 90-day period, 21 of the lead-exposed rats were treated with disodium monocalcium EDTA (50 mg/kg/d x 5 days) intraperitoneally, and 21 were administered serum saline by the same route. Three treatment courses were given separated by 9 days free of treatment. Seven rats from each subgroup were sacrificed at the end of each treatment course. Main findings related to poisoning were hypertrophy and vacuolization of medium and small arteries; mucoid edema and muscular hypertrophy in arterioles; loss of cell brush borders, cell loss, and intranuclear inclusion bodies in the proximal tubule; and fibrosis and the presence of infiltrates in the interstitial component. Treatment with EDTA slowed the progression of most alterations. No damage associated with the use of the chelating agent was observed. Longer term studies of the effects of this drug are required to establish whether the damage caused by lead poisoning may be reversed.

Animals↗
PubMed2002

Avascular necrosis of trapezium bone: a case report.

A 26-year-old woman presented with radiologic signs of avascular necrosis of the trapezium bone. Treatment by bone excision and suspension arthroplasty gave an excellent clinical result. Pathology studies confirmed the diagnosis of avascular necrosis of the trapezium.

Adult↗
PubMed2002

Angiotensin II increases parathyroid hormone-related protein (PTHrP) and the type 1 PTH/PTHrP receptor in the kidney.

Angiotensin II (AngII) participates in the pathogenesis of kidney damage. Parathyroid hormone (PTH)-related protein (PTHrP), a vasodilator and mitogenic agent, is upregulated during renal injury. The aim of this study was to investigate the potential relation between AngII and PTHrP system in the kidney. Different methods were used to find that both rat mesangial and mouse tubuloepithelial cells express PTHrP and the type 1 PTH/PTHrP receptor (PTH1R). In these cells, AngII increased PTHrP mRNA and protein production. In contrast, PTH1R mRNA was increased in mesangial cells and downregulated in tubular cells, but its protein levels were unmodified in both cells. AT(1) antagonist, but not AT(2), abolished AngII effects on PTHrP/PTH1R. The in vivo effect of AngII was further investigated by systemic infusion (a low dose of 50 ng/kg per min) into normal rats. In controls, PTHrP immunostaining was mainly detected in renal tubules. In AngII-infused rats, PTHrP staining increased in renal tubules and appeared in the glomerulus and the renal vessels. After AngII infusion, PTHR1 staining was markedly increased in all these renal structures at day 3 but remained elevated only in tubules at day 7. The AT(1) antagonist, but not the AT(2), significantly diminished AngII-induced PTHrP and PTHR1 overexpression in the renal tissue, associated with a decrease in tubular damage and fibrosis. The results indicate that AngII regulates renal PTHrP/PTH1R system via AT(1) receptors. These findings demonstrate that PTHrP upregulation occurs in association with the mechanisms of AngII-induced kidney injury.

Angiotensin II↗
PubMedDate not supplied

Ameloblastic fibroma of the mandible. Report of two cases.

The ameloblastic fibroma (AF)-ameloblastic fibro-odontoma (AFO), is an uncommon benign mixed odontogenic tumor (epithelial and mesenchymal), that represents the 2% of all odontogenic tumors. It usually appears in the mandible and in the posterior segments of young patients without gender predilection, and sometimes is associated with an impacted tooth. The classification of the WHO includes it in the subtype of odontogenic tumors with a defined histologic features. The AF and the AFO are considered as an unique entity as they are variations of the same tumor, only distinct for the presence of an odontoma in the case of the AFO. Surgical conservative treatment with excision followed by curettage seems to be the most appropriate therapeutic option. The objective of this paper is to report two cases of this tumor, to make a brief review of the literature and its differential diagnosis, to analyse its clinical and histologic features and the therapeutic option.

Ameloblastoma↗
PubMedDate not supplied

Synovial chondromatosis of the temporomandibular joint: a clinical, radiological and histological study.

Synovial chondromatosis (SC) is a cartilaginous metaplasy of the mesenchymal remnants of the synovial tissue of the joints. It is characterized by the formation of cartilaginous nodules in the synovium and inside the articular space (loose bodies). SC mainly affects to big synovial joints such as the knee and the elbow, being uncommon the onset within the TMJ, where 75 cases have been published. The main symptoms are pain, inflammation, limitation of the movements of the jaw and crepitation. Different methods of diagnosis include panoramic radiograph, CT, MR and arthroscopy of the TMJ. We report a new case of unilateral SC of the TMJ, including diagnostic images, treatment performed and histological analysis.

Arthroscopy↗