Biomedical subjects

R Marín

Publications and source records attributed to R Marín.

At least 19 recordsLinked to original sources

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↗

PubMed2001

Preeclampsia and Na,K-ATPase activity of red blood cell ghosts from neonatal and maternal blood.

We determined Na,K-ATPase activity and cholesterol/phospholipid ratio of maternal and cord red blood cell ghosts from either normotensive or preeclamptic pregnant women. The Na,K-ATPase activity of the red cell ghosts from neonatal blood is significantly lower (25-32%) as compared with the ATPase activity of the maternal red cell ghosts, regardless of the presence or not of preeclampsia. This diminution in Na,K-ATPase activity of the neonatal red blood cell ghosts could be due to an increase in the cholesterol/phospholipid molar ratio of the membrane. The Na,K-ATPase activity of the red blood cell ghosts from pregnant women was unaffected by preeclampsia; however, fetal red blood cell ghosts from infants of preeclamptic mothers showed a significantly lower ATPase activity (20%) than fetal red blood cell ghosts from infants of normotensive mothers. A low Na,K-ATPase activity in the neonatal red blood cells from mothers with preeclampsia could be an indication of an important modification of the physiological role of this enzyme.

Cholesterol↗

PubMed2001

Comparative study of the calcium adenosine triphosphatase of basal membranes of human placental trophoblasts from normotensive and preeclamptic pregnant women.

The Ca-ATPase activity of plasma membranes from human trophoblast is diminished in about 50% in preeclamptic women, as compared to normotensive pregnant women. This diminution is not due to changes in the behavior of the enzyme towards the free calcium concentration, the pH or the temperature of the incubation medium. Neither does it appear to be due to the presence of some condensing factor in the membranes, since the apparent energies of activation for the two tested ranges of temperature (10-20 and 20-37 degrees C) are similar for both normotensive and preeclamptic patients. The possibility of a diminution in the turnover rate of the Ca-ATPase in the plasma membranes from the preeclamptic patients is considered.

Adult↗

PubMed2001

[Severe maternal complications associated with pre-eclampsia: an almost forgotten pathology?].

Pre-eclampsia is a pregnancy-specific hypertensive syndrome associated with significant morbidity and mortality in mother and baby. With the increasing understanding of the disease process, the number of complications, and the maternal and perinatal deaths have fallen over the last few decades in the developed countries. In other parts of the world, the rates of mortality and morbidity remain high. We present eight cases of pre-eclamptic women with severe complications (eclampsia, HELLP syndrome, acute pulmonary edema, acute renal failure...) that were treated at our hospital in only a year, when we had not seen these pathologies in the last nine years. There was fetal death in three of the cases, related to abruptio placentae. There were no maternal deaths, but four mothers needed to be transferred to the intensive care unit, and required life-support techniques. The causes of these new events remain unclear. Can they be due to increase in maternal age or to the high incidence of abruptio placentae? Or maybe can they occur only by chance? These women with pre-eclampsia and severe complications that can have potentially devastating consequences are not an easily identified group. We concluded that women with pregnancy hypertension must be carefully managed by expert physicians, particularly if they are more than 30-35 years old, overweight, with previous history of hypertension or nulliparous, in order to decrease these several complications.

Abruptio Placentae↗

PubMed2000

Fasciola hepatica: lithogenic capacity in experimentally infested rats and chemical determination of the main stone components.

A study was done of the possible association between the development of common bile-duct stones and the presence of worms in rats experimentally infected with Fasciola hepatica. A total of 157 rats were individually infected with 20 metacercariae, and another 40 animals served as controls. The rats were dissected at 100, 200, 300, and 400 days postinfection (p.i.). A significant association was observed between the observation of stones and the presence of F. hepatica adults. The global frequency of bile-duct lithiasis in the parasitized rats was 22%, with a significantly lower incidence being observed in the younger group (100 days p.i.). Different analytical techniques were used to determine the main stone components. Energy-dispersive X-ray microanalysis showed calcium to be the main component in all cases (82-94%). Scanning electron microscopy, nuclear magnetic resonance ([1H]- and [13C]-NMR), and mass spectrometry revealed the predominance of palmitic (C-16) and stearic (C-18) acid.

Animals↗

PubMed2000

Ca-ATPase of human syncytiotrophoblast basal plasma membranes.

In the present work, a Mg(2+)-dependent, Ca(2+)-stimulated ATPase activity was determined and characterized in purified preparations of syncytiotrophoblast basal (fetal facing) plasma membranes, and its characteristics were compared to those of the active Ca(2+)-transport already demonstrated in this tissue. Similar to the active Ca(2+)transport, the Ca-ATPase is Mg(2+)-dependent, is stimulated by calmodulin, and is inhibited by vanadate. The K(m) for Ca(2+)activation is 0.25+/- 0.02microM, a value near to that described for calcium active transport in this tissue. Consequently, the Ca-ATPase activity of human syncytiotrophoblast basal plasma membrane described in this paper could be responsible for the active extrusion of calcium from the syncytiotrophoblast toward the fetal circulation.

5'-Nucleotidase↗

PubMed2000

Long-term prognosis of hypertension in pregnancy.

OBJECTIVES: To assess the prevalence of subsequent hypertension in women with hypertensive pregnancies and evaluate it according to the subclassifications of hypertension in pregnancy. METHODS: A survey was carried out in 476 women with hypertensive pregnancies (cases) and 226 normotensive controls delivered between 1973 and 1991 in a tertiary-level teaching hospital. They were invited to participate by mail and 273 cases (57%) and 86 controls (38%) completed the analysis. Outcomes assessed were prevalences of hypertension, diabetes, and hypercholesterolemia, together with cardiovascular morbidity. RESULTS: Among responders, age and parity were similar in both groups although follow-up time was longer in controls. Subsequent hypertension was more frequent within cases. After excluding chronic and unclassifiable hypertension, the mean blood pressure was higher in all other forms of pregnancy hypertension (103 +/- 13 mm Hg versus 94 +/- 13 mm Hg, p < 0.001); long-term hypertension prevalence was 45% in cases and 14% in controls [odds ratio (OR) = 5.1; 95% confidence interval (95% CI) = 2.5-9.8; p < 0. 001]. There were no differences with respect to the prevalences of subsequent diabetes or hypercholesterolemia. Remote hypertension was more common following gestational hypertension (54%) than in preeclampsia (38%), eclampsia (14%), or normotensive cases (14%) (OR for gestational hypertension versus normotensives = 7.2; 95% CI = 3. 4-14.8, p < 0.001, and OR for preeclampsia versus normotensives = 3. 7; 95% CI = 1.7-7.9, p < 0.001). CONCLUSIONS: After an average of 13. 6 years since the index pregnancy, women with hypertensive pregnancies have an increased risk of subsequent hypertension. Gestational hypertension is the hypertensive disorder of pregnancy with the highest incidence of subsequent hypertension. Women with preeclampsia have a greater tendency to develop hypertension than women with normotensive pregnancies. By contrast, women with eclampsia do not.

Adult↗

PubMed2000

Ca-ATPase of human myometrium plasma membranes.

We determined and characterized the Mg2+-dependent, Ca2+-stimulated ATPase (Ca-ATPase) activity in cell plasma membranes from the myometrium of pregnant women, and compared these characteristics to those of the active Ca2+-transport already demonstrated in this tissue. Similarly to the Ca2+-transport system, the Ca2+-ATPase is Mg2+-dependent, stimulated by calmodulin, and inhibited by vanadate. The Km for Ca2+ activation is 0.40 microM, very similar to that found for active calcium transport, i.e. 0.25 microM. Consequently, this Ca2+-ATPase can be responsible for the active calcium transport across the plasma membranes of smooth muscle cells.

5'-Nucleotidase↗

PubMed1999

Toxicological assessment of recombinant xylanase X(22) in wine.

Toxicological evaluation of xylanase X(22) from Aspergillus nidulans expressed in a wine yeast strain was carried out. The safety of the X(22) intake was assessed by digestibility, bioinformatic, and mouse short-term repeated dosing studies, although X(22) shows resistance to proteolytic degradation in the gastrointestinal system, is a minority protein component (<0.5 10(-)(6) %) of the produced wine, and shows no significant amino acid sequence homology to any known food allergens. The 4-week oral toxicity study was performed in Swiss mice at a dose level of 0.01, 0.1, or 1 mg/kg/day (these dosages correlate to 8, 80, and 800 times, respectively, the enzyme amount contained in 250 mL of wine). Body weight, food and fluid intake, urinalysis, and hematology data were obtained. Postmortem examinations and histopathology by both light and electron microscopy were performed. According to the results of this study, no adverse effects were detected by oral administration of X(22).

Allergens↗

PubMed1998

Preeclampsia, lipid peroxidation, and calcium adenosine triphosphatase activity of red blood cell ghosts.

OBJECTIVE: We evaluated the effect of lipid peroxidation on the calcium adenosine triphosphatase activity of red blood cell ghosts from normotensive pregnant women and compared it with the adenosine triphosphatase activity and lipid peroxidation in preeclampsia. STUDY DESIGN: Ten nulliparous normotensive and 10 nulliparous preeclamptic pregnant women (38 to 39 weeks of gestation) were used as blood donors. Preeclampsia was diagnosed on the basis of blood pressure (>140/90 mm Hg) and proteinuria (>0.5 gm of urinary protein per day). Red blood cell ghosts were prepared for both groups and used for calcium adenosine triphosphatase activity and lipid peroxidation determinations. Control ghosts (normotensive) were irradiated with ultraviolet light for different lengths of time. RESULTS: Calcium adenosine triphosphatase activity of red blood cell ghosts from normotensive women is sensitive to lipid peroxidation. The lipid peroxidation of red blood cell ghosts from preeclamptic women is higher than that from normotensive women. CONCLUSION: The diminution of the calcium adenosine triphosphatase activity with preeclampsia could be explained by the sensitivity of this adenosine triphosphatase to lipid peroxidation.

Adult↗

PubMed1998

Ouabain-insensitive Na(+)-ATPase activity of Malpighian tubules from Rhodnius prolixus.

In the present paper, we show the existence of a furosemide-sensitive Na(+)-stimulated, Mg(2+)-dependent ATPase activity in cell lysates of Malpighian tubular cells from Rhodnius prolixus, which could be the biochemical expression of the Na(+)-pump. The main characteristics of this activity are: (1) K0.5 for Na+ = 1.49 +/- 0.18 mM, (2) Vmax = 2.8 +/- 0.1 nmol inorganic orthophosphate (Pi).mg prot-1.min-1, (3) it is fully abolished by 2 mM furosemide, (4)it is insensitive to ouabain concentrations up to 10(-2) M, (5) it is sensitive to the presence of vanadate in the incubation medium indicating it to be a P-type ATPase, and (6) it is stimulated by nanomolar concentrations of Ca2+ in the incubation medium.

Adenosine Triphosphatases↗

PubMed1998

[Hepatocellular carcinoma associated to porphyria cutanea tarda and hepatitis C virus infection without cirrhosis].

The molecular basis of porphyria cutanea tarda is defective activity of hepatic uroporphyrinogen decarboxylase. A common characteristic is liver dysfunction than goes from cirrhosis to hepatocellular carcinoma. A high prevalence of hepatitis C virus markers has been demonstrated. We study a patient with PCT and hepatitis C virus markers that finally develops to hepatocellular carcinoma without previous cirrhosis. Previous studies with association of PCT and hepatitis C virus markers, have found liver diseases ranging from cirrhosis to hepatocellular carcinoma. The importance of this study is the absence of cirrhosis.

Carcinoma, Hepatocellular↗

PubMed1998

[Clock drawing test: qualitative and quantitative evaluation methods].

INTRODUCTION: The interest about the Clock Drawing Test (CDT) is justified because the importance of praxic disorders and especially the constructive apraxias in demented patients. Generally, this kind of deficits or intellectual losses has been less studied than aphasisas and agnosias. Nevertheless, praxias are usually affected in demential processes, even in initial stages. OBJECTIVE: We try to determine if the CDT can be useful as an assessment tool for dementia. We have used two assessment systems of the clock drawing in order to select an useful and reliable method of correction. PATIENTS AND METHODS: The sample is made up of 35 subjects older than 60 years, they were administered the Mini Cognitive Examination (MCE) and the CDT. Patients with previous diagnosis of dementia, others with physical pathology without neurological affectation and, finally, subjects without any kind of pathology were included in order to get a wide rank of punctuations. We carried out a reliability analysis between two raters and the discriminant validity of the CDT compared to the Spanish adaptation of the Mini Mental Examination. RESULTS: We achieve a high reliability inter examiner rates. Quantitative criteria of both scales are more objective than qualitative ones, therefore, these last should be more operativized. CONCLUSIONS: The results obtained in this work suggest that the clock drawing allow a rapid evaluation of cognitive function as the presence of cognitive impairment.

Aged↗

PubMed1997

A family with a milder form of adult dominant polycystic kidney disease not linked to the PKD1 (16p) or PKD2 (4q) genes.

Autosomal dominant polycystic kidney disease (ADPKD) is a genetically heterogeneous disease. Most families show positive linkage to polymorphic markers around the PKD1 (16p13.3) or PKD2 (4q21-23) loci. The PKD1 and PKD2 genes have been cloned and mutations defined in a number of patients. Several clinical studies have described a milder phenotype for PKD2 patients. More recently, evidence for a third genetic locus has been found in one Portuguese, one French-Canadian, and one Italian family. We identified a Spanish family with negative linkage to the PKD1 and the PKD2 loci. This family showed a very mild clinical phenotype compared to the other forms of ADPKD, including the non-PKD1/non-PKD2 families previously described.

Adult↗