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Biomedical subjects

M Arias

Publications and source records attributed to M Arias.

At least 37 records · Page 2Linked to original sources
PubMed2002

Molecular differentiation between NS1 gene of a field strain Bluetongue virus serotype 2 (BTV-2) and NS1 gene of an attenuated BTV-2 vaccine.

At the end of September 2000, clinical symptoms of Bluetongue appeared in sheep flocks of the Balearic Islands (Spain). The presence of the BTV serotype 2 in tissue and blood samples of affected animals was confirmed by laboratory techniques. A systematic vaccination were carried out in affected areas using a live monovalent serotype 2 vaccine available from Onderstepoort laboratory (South Africa). In order to perform epidemiological studies, a new method to differentiate between the NS1 genes of BTV-2 affecting the Balearic islands and that of the Onderstepoort commercial live virus vaccine (monovalent, serotype 2) has been developed. This procedure is based on the use of an RT-PCR, followed by restriction endonuclease analysis. Epidemiological data of a study carried out in the period January-October 2001 using this procedure are included.

Animals↗
PubMed2002

Enhancement of copper and cadmium adsorption on kaolin by the presence of humic acids.

The competitive adsorption equilibrium isotherms of Cu2+ and Cd2+ on kaolin have been measured at 298 K, in the presence and the absence of humic acids (HAs). HAs were found to enhance the metal adsorption capacity of mineral surfaces, in particular kaolin. This enhancement was also observed in the competitive adsorption of copper and cadmium on kaolin and kaolin-HA complex. This competitive adsorption shows that the presence of Cd2+ has not an important effect on Cu2+ adsorption, whereas a dramatic decrease is observed on the adsorption of Cd2+ in the presence of Cu2+. The Freundlich isotherm equation was found to provide an excellent fit to the experimental data. These results were compared with the independent adsorption of both heavy metals.

Adsorption↗
PubMed2002

Bone cell mitogenic action of fluoroaluminate and aluminum fluoride but not that of sodium fluoride involves upregulation of the insulin-like growth factor system.

The fluoroaluminate (AlF(4)(-)) ion and sodium fluoride (NaF) have previously been shown to be bone cell mitogens. This study sought to determine whether the bone cell mitogenic action of AlF(4)(-) and/or NaF would involve the insulin-like growth factor (IGF) regulatory system. We evaluated the effect of mitogenic doses of AlF(4)(-) and NaF on the mRNA levels and the protein level (in conditioned media [CM]) of several components of the IGF system (i.e., IGF-2, IGF binding protein [IGFBP]-4, and IGFBP-5) in human TE85 osteosarcoma cells. Aluminum fluoride (AlF(3)) was included for comparison. NaF, AlF(3), and AlF(4)(-), each at 50-100 micromol/L, increased [3H]thymidine incorporation in TE85 cells. Mitogenic concentrations of AlF(3) and AlF(4)(-): (1) increased the mRNA (up to twofold after 24 h treatment) and protein (in CM) levels (up to 2.5-fold after 48 h treatment) of IGF-2; (2) increased the mRNA level (twofold) and the protein level in CM (up to threefold) of stimulatory IGFBP-5; and (3) either reduced slightly or had no effect on the mRNA and protein (in CM) levels of the inhibitory IGFBP-4. Conversely, mitogenic concentrations of NaF had no significant effects on the protein (in CM) or mRNA level of IGF-2, IGFBP-4, or IGFBP-5. The addition of an inhibitory concentration of IGFBP-4 completely abolished the bone cell mitogenic activity of AlF(3) and AlF(4)(-) but not that of NaF. The findings of this study provide strong evidence that the bone cell mitogenic activity of AlF(4)(-) and AlF(3), but not that of NaF, is mediated by the upregulation of the IGF regulatory system.

Aluminum↗
PubMed2002

Parathyroidectomy in dialysis patients.

Subtotal parathyroidectomy or total parathyroidectomy (PTx) with autotransplantation are surgical procedures considered while the patient is included on the waiting list for renal transplantation. Total PTx alone is based in the possibility that a fragment of tissue (nodular hyperplasia in particular) left in the same pathophysiological environment of long term dialysis would show the same behavior and reproduce in time the same clinicopathological picture. The persistence of uremia induces a continued growth stimulus developing residual hyperplasia and consequently a very high risk of recurrence. We performed total PTx alone in 15 uremic patients excluded for renal transplantation 10 patients with undetectable iPTH serum concentration and were followed up for 37 to 144 months. There was no evidence of clinical bone disease (bone pain or fractures). Bone mineral lumbar spine and hip density was measured at the end of follow-up. The z score data showed that all patients had a bone mass similar than that expected for their age. Bone biopsies performed in four patients showed a uniform picture of low turnover without aluminium staining. Calcification of small arteries (digital and arcade vessels in hands and feet) were evaluated pre and post total PTx alone in nine out of the 10 patients with undetectable PTH levels. The small vessel calcification was present in five patients at the moment of PTx. At the end of the long term follow-up only one patient showed progression. In conclusion, total PTx without autotransplantation is a very effective and adequate treatment for refractory severe hyperparathyroidism in patients excluded for renal transplantation. Aluminium related osteopathy post PTx is a risk to be controlled with aluminium "free" dialysis water and avoiding aluminium containing phosphate binders.

Calcitriol↗
PubMed2002

["Occult" renal insufficiency due to evaluating renal function using only serum creatinine].

Timely referral to nephrologists depends on identification of renal failure. Most primary care physicians and specialists rely on serum creatinine as the standard test for determination of renal function. Creatinine clearance requires 24 hours urine collection with many pitfalls and wrong results. We compare serum creatinine and the Cockcroft-Gault (C-G) equation as measure of glomerular filtration rate (GFR). The study included 1,053 outpatients with serum creatinine lower than 2.5 mg/dl referred to our nephrological laboratory for serum creatinine and GFR determination using the C-G formula. Patients were grouped into two groups: normal renal function (serum creatinine < 1.3 mg/dl) and "incipient" abnormal renal function (serum creatinine 1.3-2.5 mg/dl). In the group of females with normal creatinine 22% (60-70 y), 35% (70-80 y) and 57% (> 80 y) had GFR values below 50 ml/min. In the group of males 11.3% (70-80 y) and 33.3% (> 80 y) also had GFR reduction in spite of normal serum creatinine. A severe renal insufficiency with creatinine clearance lower than 30 ml/min was observed in the group with "incipient" renal failure based on serum creatinine: 22.7%, 40% and 82.9% for females and 6%, 22.7% and 57% for male (60-70 y; 70-80 y; and > 80 y respectively). In order to improve management and prevention of renal failure appropriate measurements of renal function other than serum creatinine should be emphasize.

Adult↗
PubMed2001

Tumoral calcinosis presenting as an extradural mass: MR findings and pathological correlation.

Two cases of idiopathic tumoral calcinosis presenting as an extradural mass are reported. There are few reports in the literature of this pathological process presenting as extradural masses, so both cases represent very unusual locations for tumoral calcinosis. Magnetic resonance imaging features and pathological correlation of these two cases are presented. Tumoral calcinosis might be considered as a rare but possible cause of extradural mass.

Calcinosis↗
PubMed2001

Unusual presentation of a pancreatic insulinoma in helical CT and dynamic contrast-enhanced MR imaging: case report.

Insulinomas are pancreatic neoplasms that can be radiologically characterized typically because of their tendency to present intense and early contrast enhancement with a wash-out phenomenon. In this sense, we report an unusual case of a hypovascular solid pancreatic insulinoma confirmed with surgery and pathologic analysis, in a patient with normal serum insulin levels. In the two-phase helical CT, the mass behaved as a hypodense lesion with respect to the surrounding pancreatic parenchyma during the arterial phase and as a hypointense lesion during the dynamic contrast-enhanced MR imaging. Pathologic examination demonstrated a hypercellular tumor with poor vascularization of intervening stroma which showed prominent amyloid deposits.

Aged↗