Biomedical subjects

X L Otero

Publications and source records attributed to X L Otero.

7 recordsLinked to original sources

PubMed2005

Trace elements in biodeposits and sediments from mussel culture in the Ria de Arousa (Galicia, NW Spain).

The trace elements present at highest concentrations were Cr and Zn, which probably originated from the dumping of effluent from a tanning factory. High proportions of these two elements were associated with the residual fraction. Biodeposits and sediments showed high concentrations of Cd and Pb in the reactive fraction, with a high proportion of the concentration in the reactive fraction being associated with carbonates. Nickel showed a higher degree of pyritization than the previous elements, although most of the Ni was associated with the residual and reactive fractions. Arsenic, Hg and Cu showed high degrees of pyritization, particularly below a depth of 5 cm. The results demonstrate that those elements with a high degree of pyritization may be released into the water through oxidation of the metal sulphides that they form when in suspension in oxic sea water, with the subsequent risk of increased bioavailability to benthic fauna.

Animals↗

PubMed2002

Clinical and pathological characteristics of oral lichen planus in hepatitis C-positive and -negative patients.

The reported prevalence rate of anti-hepatitis C virus (HCV) antibodies in patients with oral lichen planus shows wide geographical variation and ranges from 0 to 65%. Certain characteristic clinical features have been attributed to oral lichen planus associated to HCV infection. The purpose of this investigation has been to assess hypothetical clinical differences, as well as differences in the intensity of the subepithelial inflammatory infiltrate between oral lichen planus-HCV +ve patients and oral lichen planus-HCV -ve patients. A total of sixty-two patients entered the study. Their mean age was 63.5 +/- 14.49 years, and 48.4% of them were men and 51.6% women. Patients were classified according to their serum HCV positivity. Age, sex, clinical presentation (reticular or atrophic-erosive), extension of the lesions, location of the lesions, number of locations affected, intensity of the inflammatory infiltrate and Candida albicans colonization were recorded for each patient. Reticular lichen planus was the most frequent clinical presentation in both HCV +ve (57.1%) and HCV -ve patients (63.6%). C. albicans colonization ranged from 42.8% in HCV +ve and 41.7% in HCV -ve patients. HCV + ve patients showed certain oral locations more frequently affected than HCV -ve ones: lip mucosa, 28.6% versus 7.3%; tongue, 57.1% versus 29.1%; and gingiva, 71.4% versus 23.6%. The number of affected intraoral locations was higher in HCV +ve patients (71.4%) than among HCV -ve ones (20.4%; chi2 = 8.34; P < 0.011). No statistically significant differences could be established in terms of density of subepithelial inflammatory infiltrate between the groups. Our results reinforce the need for liver examination in all patients with oral lichen planus, particularly those showing lesions on the gingiva with multiple intraoral locations affected, as no pathological differences could be identified between HCV + ve and HCV -ve patients.

Candidiasis, Oral↗

PubMed2001

Growth hormone secretagogues as diagnostic tools in disease states.

One of the most active topics in the growth hormone-IGF-1 field is that of the so-called growth hormone secretagogues (GHS). At a time when the isolation of GHRH had not occurred, the GHS were developed as artificial tools to release GH. The interest in these groups of compounds was rekindled when it was realized that they were not surrogates of GHRH nor were they acting through the modulation of the release of either GHRH or somatostatin. With the subsequent cloning of the specific receptor of GHS, and today of the natural ligand for that receptor, named ghrelin, it soon become clear that GHS and the GHS-receptor were part of a new physiological system involved in GH regulation. The dual control of GH secretion became a trinity. GHS releases GH when administered by any route--oral, iv, sc, and even transdermally-with a surprising potency and reproductivity. In addition, GHS when administered together with GHRH exert a synergistic action on GH secretion and that combined administration is the most potent GH releaser to date. Clinical studies have demonstrated that the GHS-GHRH administration may be considered the new "gold standard" test of GH reserve in humans, as the GH secretion so elicited is not altered by gender, adiposity, or age. The combined administration of GHRH plus GHS is able to discriminate between healthy subjects and patients with adult GH deficiency, suggesting a considerable utility in the clinical setting.

Adult↗

PubMed2001

A new perspective in the estimation of postmortem interval (PMI) based on vitreous.

The relation between the potassium concentration in the vitreous humor, [K+], and the postmortem interval has been studied by several authors. Many formulae are available and they are based on a correlation test and linear regression using the PMI as the independent variable and [K+] as the dependent variable. The estimation of the confidence interval is based on this formulation. However, in forensic work, it is necessary to use [K+] as the independent variable to estimate the PMI. Although all authors have obtained the PMI by direct use of these formulae, it is, nevertheless, an inexact approach, which leads to false estimations. What is required is to change the variables, obtaining a new equation in which [K+] is considered as the independent variable and the PMI as the dependent. The regression line obtained from our data is [K+] = 5.35 + 0.22 PMI, by changing the variables we get PMI = 2.58[K+] - 9.30. When only nonhospital deaths are considered, the results are considerably improved. In this case, we get [K+] = 5.60 + 0.17 PMI and, consequently, PMI = 3.92[K+] - 19.04.

Adult↗

PubMed2000

Toxic epidermal necrolysis and Stevens-Johnson syndrome: does early withdrawal of causative drugs decrease the risk of death?

BACKGROUND: Withdrawal of the drug(s) that cause severe cutaneous adverse reactions is usually recommended without proof that it alters the course of those reactions. OBJECTIVE: To determine whether the timing of causative drug withdrawal is related to the prognosis of patients with toxic epidermal necrolysis (TEN) or Stevens-Johnson syndrome (SJS). DESIGN: A 10-year observational study (January 1, 1987, through October 30, 1997) of patients admitted to a dermatological intensive care unit, using binary logistic regression analysis. SETTING: A single referral unit in a university hospital. PATIENTS: Consecutive sample of 203 patients with TEN or SJS. Exclusion criteria included causative drug undetermined, lack of information on disease evolution, the date of causative drug(s) withdrawal, or the date when the first definite sign of TEN or SJS appeared. MAIN OUTCOME MEASURE: Death before hospital discharge. RESULTS: One hundred thirteen patients were included; 74 had TEN and 39 had SJS; 20 died. The drug causing TEN or SJS was withdrawn early in 64 patients and late (after the first definite sign of TEN or SJS) in 49 patients. After adjustment for confounding variables (age, maximum extent of detachment, admission year, human immunodeficiency virus status), our model showed that the earlier the causative drug was withdrawn, the better the prognosis (odds ratio, 0.69 for each day; 95% confidence interval, 0.53-0.89). Patients exposed to causative drugs with long half-lives had an increased risk of dying (odds ratio, 4.9; 95% confidence interval, 1.3-18.9). The variables did not interact. CONCLUSIONS: Prompt withdrawal of drug(s) that are suspected to cause SJS or TEN may decrease mortality. Prompt withdrawal of causative drugs should be a priority when blisters or erosions appear in the course of a drug eruption.

Adult↗

PubMed2000

Heavy metal geochemistry of saltmarsh soils from the Ría of Ortigueira (mafic and ultramafic areas, NW Iberian Peninsula).

Concentrations of Fe, Mn, Ni, Cu, Cr and Zn in their total, silicate, organic, reactive and pyrite fractions were determined in soils collected from the Ortigueira saltmarshes (Esteiro, Ladrido and Mera, NW Iberian Peninsula), from sediments of the Landoi and Esteiro Rivers, and from sludge generated by a nearby dunite mine. The Esteiro saltmarsh presented clear enrichments of the four metals studied (first 10 cm), especially of Ni and Cr, whose concentrations were among the highest. It is proposed that the elevated Cr and Ni levels found in the Esteiro saltmarsh were derived from recent contributions of the mine, which are partially discharged into the Landoi River. Total Cu and Zn concentrations were lower than the corresponding ones for Cr and Ni. Under suboxic conditions, Ni, Cr, Cu and Zn were mainly associated with the reactive fraction. Under anoxic conditions, Cu and Ni were associated mainly with the pyrite phase. Pyritic Zn and Cr concentrations were relatively low and similar in all three saltmarshes; however, where anoxic-sulfidic conditions prevailed these two metals were mainly associated with the reactive and organic fractions.

Journal Article↗

PubMed1996

Reporting delay: a review with a simulation study and application to Spanish AIDS data.

To correct for the effect of reporting delay on incidence data relating to AIDS, three methods of estimation have been analysed: Poisson log-linear; log-linear logistic mixed regression (log-logit), and truncation. The first two methods transform the data in a contingency table. The difference between them is the hypothesis of delay stationarity, which is only assumed by the former. A correction is proposed for the first method to improve its asymptotic properties. The truncation method is based on the product-limit estimator. A simulation study was carried out to examine the behaviour (means, variances and mean squared errors) of the three methods. All were applied to data from the National Commission on AIDS (Spain), showing an improvement in reporting efficiency.

Acquired Immunodeficiency Syndrome↗