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Biomedical subjects

R Marín

Publications and source records attributed to R Marín.

At least 19 recordsLinked to original sources
PubMed2006

[Renal function and cardiovascular risk in patients with essential hypertension. The "FRESHA" study].

BACKGROUND: In the past few years there has been a growing amount of information about renal dysfunction and cardiovascular risk. The objectives of this study were to assess the prevalence of renal dysfunction and evaluate the relation between renal function and cardiovascular risk in patients with essential hypertension. METHODS: A multicenter, cross-sectional survey of unselected patients with essential hypertension attending primary care settings in Spain was performed between june and november 2004. Renal function was evaluated with the abbreviated equation of the Modification of Diet in Renal Disease study. Renal insufficiency was defined as an estimated glomerular filtration rate <60 ml/min/1.73 m2. RESULTS: Eighty-eight investigators from 50 centers recruited 2130 patients being mean age 65.6 +/- 11 years and female 53%. Prevalence of diabetes, lipid abnormalities, and previous cardiovascular disease were 30.3%, 45.9%, and 42.1% respectively. Prevalence of renal insufficiency was 32.4% (95% CI 30.4-34.4). Patients suffering from renal insufficiency showed a higher prevalence of cardiovascular disease when comparing with those with an estimated glomerular filtration rate = or >60 ml/min/1.73 m2 (56.2% vs. 35.3%, OR 2.35, 95% CI 1.95-2.82, p < 0.001). A logistic regression analysis showed that the relation of renal dysfunction with cardiovascular disease was independent of other variables or classical cardiovascular risk factors as age, female sex, diabetes, smoking, hypercholesterolemia, and systolic blood pressure. CONCLUSIONS: Renal insufficiency was present in 32.4% of patients with essential hypertension attending primary care settings. Cases with renal dysfunction showed a higher cardiovascular risk. Hypertensive patients with renal insufficiency should be considered as candidates for an aggressive approach of cardiovascular risk management.

Aged↗
PubMed2005

[Pharmacogenetics of angiotensin system in non diabetic nephropathy].

BACKGROUND: Genetic variability could contribute to the response to pharmacological treatment in patients with nephropathy. In albuminuric diabetic patients the renoprotective effect of angiotensin I-converting enzyme (ACE) inhibition should be lower among homozygotes for the deletion allele (DD) compared to II-homozygotes. METHODS: A total of 71 non-diabetic chronic nephropathy patients were treated with losartan (n = 37) or amlodipine (n = 34). Blood pressure and proteinuria were determined before and after the treatment, and changes in the mean values were statistically compared. Patients were genotyped for the ACE-I/D, angiotensin I receptor type 1 (AGTR1)-1166 A/C, and angiotensinogen (AGT)-M235T polymorphims, and the reduction of blood pressure and proteinuria between the different genotypes were compared. RESULTS: The reduction in systolic or diastolic blood pressure was not found to be different between the ACE-I/D or AGT-M/T genotypes in patients treated with losartan or amlodipine. In patients treated with losartan, we found a significantly higher reduction of diastolic blood pressure in AGTR1-AA patients compared to AC patients (p = 0,0024). We did not find differences in proteinuria-reduction between the different genotypes in patients treated with losartan or amlodipine. CONCLUSIONS: Our data show that the effects of losartan and amlodipine on the absolute mean reduction of blood pressure and proteinuria in non-diabetic nephropathy patients are similar between the different ACE or AGT genotypes. Although based on a small number of patients, the AGTR1-AA genotype was associated with a significantly higher reduction in diastolic blood pressure among losartan-treated patients. Additional studies are necessary to refute or confirm this association.

Adult↗
PubMed2004

Gas chromatographic evaluation of pesticide residue contents in nectarines after non-toxic washing treatments.

Washing with aqueous solutions of citric acid, ethanol, glycerol, hydrogen peroxide, potassium permanganate, sodium metabisulfite, sodium laurylsulfate (SLS), sodium hypochlorite, and urea is evaluated for pesticide residue reduction in nectarines and compared with simple tap water washing. Residues of pesticides commonly utilized in nectarines (chlorpyrifos, fenarimol, iprodione, malathion, methidathion, myclobutanil, parathion and pirimicarb) are extracted with ethyl acetate and anhydrous sodium sulfate, extract is concentred and analyzed by GC with nitrogen-phosphorus detection. The formation of possible toxic by-products (chlorpyrifos oxon, malaoxon, methidaoxon and paraoxon methyl) is studied by GC-MS. No toxic by-products are identified in the extracts of the washed samples for the washing-time and concentrations studied, but high levels of sodium hypochlorite, hydrogen peroxide and potassium permanganate form oxons from the organophosphorus pesticides. Ethanol, glycerol and SLS solutions removed near the 50% of the pesticide residues. The other solutions were not more effective than tap water washing. The amount of pesticide removed by washings is related to its water solubility and octanol-water partition coefficient.

Chromatography, Gas↗
PubMed2004

Occurrence and distribution of pesticides in the province of Bologna, Italy, using honeybees as bioindicators.

Samples of honeybees (Apis mellifera, n = 92) from 14 beehive monitoring stations located in 3 townships in the province of Bologna were analyzed from April to October 2000. The concentration of 32 organophosphorus pesticides and 5 carbamates was determined through liquid-liquid extraction followed by gas chromatography with a nitrogen-phosphorus detector and liquid chromatography coupled to mass spectrometry using atmospheric pressure chemical ionization in positive and negative ion modes. The most contaminated samples were from Granarolo Emilia where cereals (wheat, sorghum, and corn), sugar beets, and potatoes are the main agriculture products. Thirty-five pesticides were detected, with organophosphorus being the most abundant ones. Malathion was detected in 58% of the samples (mean level 0.360 mg/kg) followed by fenithrothion in 53% of the samples (mean level 0.544 mg/kg) and pirimiphos methyl in 48% of the samples (mean level 0.006 mg/kg). Temporal trends showed that the maximum detection frequency occurred in late spring and was associated with the use of treatment products and less rainfall. The obtained results demonstrated the feasibility of using honeybees for assessing pesticide exposure in agriculture settings.

Agriculture↗
PubMed2004

Human articular chondrocytes, synoviocytes and synovial microvessels express aquaporin water channels; upregulation of AQP1 in rheumatoid arthritis.

Recent studies have shown that aquaporin water channels are expressed in human Meckel's cartilage. The aim of the present investigation was to determine if human articular chondrocytes and synoviocytes express aquaporin 1 (AQP1) water channels and to establish if there are any alterations in AQP1 expression in osteoarticular disorders such as osteoarthritis (OA) and rheumatoid arthritis (RA). Immunohistochemistry was employed semi-quantitatively to compare the expression of AQP1 in human chondrocytes derived from normal, OA and RA joints. PCR, cloning and sequencing confirmed the presence of AQP1 transcripts in chondrocytes. Normal human tissue microarrays including samples of kidney, choroid plexus and pancreas were used as positive controls for AQP1 expression. In most tissues AQP1 was expressed along endothelial barriers. In the kidney AQP1 was present in the glomerular capillary endothelium, proximal tubule and descending thin limbs. AQP1 was also localized to pancreatic ducts and acini and the apical membrane domain of the choroid plexus. Immunohistochemistry showed that AQP1 is expressed in synovial micro-vessels, synoviocytes and predominantly in chondrocytes located in the deep zone of articular cartilage. Image analysis of normal, OA and RA cartilage suggested that AQP1 may be upregulated in RA. This is the first report of AQP1 mRNA and protein expression in articular chondrocytes and synoviocytes. These findings suggest a potential role for AQP1 and possibly other members of the AQP gene family in the movement of extracellular matrix and metabolic water across the membranes of chondrocytes and synoviocytes for the purposes of chondrocyte volume regulation and synovial homeostasis.

Aquaporin 1↗
PubMed2003

Determination of aflatoxins in peanuts by matrix solid-phase dispersion and liquid chromatography.

A new method based on matrix solid-phase dispersion (MSPD) extraction was studied to determine aflatoxin B1, B2, G1 and G2 from peanuts. Optimization of different parameters, such as type of solid supports for matrix dispersion and elution solvents were carried out. The method used 2 g of peanut sample, 2 g of C18 bonded silica as MSPD sorbent and acetonitrile as eluting solvent. Recoveries of each aflatoxin spiked to peanut samples at 2.5 ng/g (5 ng/g for aflatoxin G2) level were between 78 and 86% with relative standard deviations ranging from 4 to 7%. The limits of quantification ranged from 0.125 to 2.5 ng/g for the four studied aflatoxins using liquid chromatography (LC) with fluorescence detection. In addition, LC coupled to mass spectrometry with an electrospray interface was used for confirmation of aflatoxins present in real samples. Eleven peanut samples from different countries were analyzed by the proposed method and by using an enzyme-linked immunosorbent assay (ELISA). ELISA test is a good screening method for investigation of these mycotoxins in peanut samples.

Aflatoxins↗
PubMed2002

Application of matrix solid-phase dispersion to the determination of a new generation of fungicides in fruits and vegetables.

A method based on matrix solid-phase dispersion (MSPD) and gas chromatography to determine eight fungicides in fruits and vegetables is described. Fungicide residues were identified and quantified using nitrogen-phosphorus detection and electron-capture detection connected in parallel and confirmed by mass spectrometric detection. The method required 0.5 g of sample, C18 bonded silica as dispersant sorbent, silica as clean-up sorbent and ethyl acetate as eluting solvent. Recoveries from spiked orange, apple, tomato, artichoke, carrot and courgette samples ranged from 62 to 102% and relative standard deviations were less than 15% in the concentration range 0.05-10 mg kg(-1). Detection and quantitation limits ranged 3-30 microg kg(-1) and 10-100 microg kg(-1), respectively, with linear calibration curves up to 10 mg kg(-1). The analytical characteristics of MSPD compared very favourably with the results of a classical multiresidue method, which uses ethyl acetate and anhydrous sodium sulphate for the extraction.

Chromatography, Gas↗
PubMed2002

[Arterial hypertension and renal vascular disease: nephroangiosclerosis].

Nephroangiosclerosis and nephrosclerosis are terms used to define the renal disease induced by essential hypertension. The predominant histologic changes occur in the preglomerular microvasculature. Epidemiological data about the risk of hypertensive patients from developing renal failure offer conflicting results. Nevertheless, renal vascular disease, including nephroangiosclerosis and/or ischemic nephropathy, appears to be an important cause of end-stage renal disease. Presumably, nephrosclerosis is the renal expression of systemic atherosclerosis: male sex, age > 55-60 years, black race, high serum cholesterol and/or uric acid levels, and coronary heart disease, peripheral artery disease, and/or cerebrovascular disease are common associations with the renal alteration. Treatment strategy should include an intensive blood pressure control, probably below 130/80 mmHg, together with antiplatelet and lipid-lowering agents when necessary. Although specific studies are lacking, ACE inhibitors and angiotensin II antagonists may offer additional benefits in slowing the renal disease progression.

Humans↗
PubMed2002

[Prevalence of renal involvement in a population of type Ii diabetics followed up in primary care].

UNLABELLED: Patients with type 2 diabetes use to be managed in their primary care settings during the early stages of the disease. The main objective of the study was to determine renal impairment prevalence, and to assess its significance, within type 2 diabetics controlled by their family physicians. PATIENTS AND METHOD: Transverse observation of patients with type 2 diabetes who were the first 20 unselected cases seen by 183 family physicians from 16 of the 17 Autonomic Communities of our country. The following variables were determined: serum creatinine, glucose, and HbA1c concentrations, proteinuria (dipstick test in a first-voided morning urine sample), blood pressure levels, and associated cardiovascular disease. RESULTS: Data from 3,583 type 2 diabetic subjects were evaluated. Mean age was 64 +/- 10 years and 45% were male. A serum creatinine > or = 1.2 mg/dl was observed in 523 (15.5%) patients. Proteinuria was present in 794 (23.5%) cases, being > or = 2 + in 215 (6.5%) subjects. Patients with a serum creatinine > or = 1.2 mg/dl were older, shower higher blood pressure levels, and suffered from more cardiovascular disease (32.0 vs 19.5%) than those with a serum creatinine < 1.2 mg/dl. In a multivariate analysis, this difference continued to be significant (OR 1.47; 95% CI 1.14 to 1.90; p = 0.002. Patients with proteinuria showed a higher prevalence of cardiovascular disease (OR 1.83; 95% CI 1.47 to 2.27; p < 0.0001) than those without proteinuria. This association was continuous through no proteinuria to the > or = 2 + proteinuria (p < 0.001). Blood pressure level was > or = 140/90 mmHg in 69% of the cases, being < 130/85 mmHg in only 8% of the subjects. CONCLUSIONS: There is a high prevalence of renal impairment, approximately of 25% within type 2 diabetic patients seen at the primary care level. Optimal blood pressure level seems to be extremely infrequent bearing in mind the diagnosis of diabetes and the associated cardiovascular disease.

Aged↗
PubMed2001

Estrogen modulates norepinephrine-induced accumulation of adenosine cyclic monophosphate in a subpopulation of immortalized luteinizing hormone-releasing hormone secreting neurons from the mouse hypothalamus.

A subpopulation of luteinizing hormone-releasing hormone (LHRH)-producing cells that express the intermediate filament protein vimentin and the neuronal marker neurofilament 145, but not neurofilament 200 nor glial fibrillary acidic protein, has been isolated from GT1-7 cultures. These cells express the mRNA encoding estrogen receptor alpha (ERalpha) and respond to physiological concentrations of 17beta-estradiol (E2) by reducing the accumulation of cyclic adenosine monophosphate induced by norepinephrine, but not that induced by direct activation of adenylate cyclase. These results indicate that the activity of LHRH-producing neurons may be directly modulated by estrogen. In addition, they are suggestive of an estrogen-dependent desensitization of the beta-adrenoceptor in these cells.

Animals↗
PubMed2001

Clinical characteristics of ischaemic renal disease.

BACKGROUND: Longer life expectancy has favoured the ever more frequent development of ischaemic nephropathy characterized by the presence of atherosclerotic stenosis in both renal arteries. METHODS: This is an observational and multicentre study carried out during a 14-month follow-up period in 20 hospitals in SPAIN: Inclusion criteria were the presence of bilateral renal artery stenosis > 50% and a creatinine level of > or = 1.5 mg/dl. The diagnosis should be made by arterial digital angiography in every case. RESULTS: A total of 156 patients were included. Their mean age was 68.7+/-9 years, and 78.5% were male. The mean creatinine value of the group was 2.9+/-1.7 mg/dl. Arterial hypertension (BP) with a duration of 12+/-9 years was present in 97.4% of the cases, smoking habits in 69.8%, hypercholesterolaemia (> or = 240 mg/dl) in 62.9% and diabetes in 32.1%. Only 8% of the patients had a body mass index > or = 30 kg/m(2). Associated cardiovascular disease was very frequent: peripheral arteriopathy in 67.5% of the cases, ischaemic cardiopathy in 44.8%, cardiac insufficiency in 32.6% and stroke in 27.3%. In 94.4% of the patients, the lesion affected both renal arteries, with complete obstruction in 23% of the cases. CONCLUSIONS: Diagnostic suspicion of ischaemic nephropathy can be established in non-obese elderly males with chronic renal insufficiency, long-term BP evolution and cardiovascular disease at other levels, above all, peripheral arteriopathy.

Aged↗