Immunoassay method for the determination of pentachlorophenol in soil and sediment.
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Biomedical subjects
Publications and source records attributed to F Rubio.
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OBJECTIVE: The Transverse Myelitis Consortium Working Group has proposed new diagnostic criteria for idiopathic acute transverse myelitis (ATM). We reviewed patients admitted to our center diagnosed with myelitis with two objectives: (i) to evaluate the usefulness of these criteria in distinguishing between myelitis as the first episode of multiple sclerosis (MS) and idiopathic ATM; and (ii) to analyse the clinical and laboratory variables that may be used as functional prognostic markers. METHODS: We selected patients who met the criteria. We recorded clinical epidemiological data, patients treated with methylprednisolone, maximal disability reached and disability at final follow-up. We also recorded cerebrospinal fluid (CSF) data and the number of levels affected in the spinal magnetic resonance imaging (MRI). RESULTS: Twenty-four patients fulfilled the criteria for definite ATM and 21 for possible ATM. Five patients converted to MS. Mean follow-up time was 3.5 years. There was an association between younger patients and female patients with conversion to MS. The highest Rankin score reached and increased CSF glucose levels were associated with a poor outcome. In multivariate analysis, only the admission Rankin score was associated with outcome. CONCLUSIONS: (i) About 10% of patients who met the criteria may convert to MS; and (ii) admission Rankin score was the only independent prognostic factor found.
INTRODUCTION: Spontaneous subarachnoid hemorrhage (SAH) is idiopathic in 15% of cases. They represent a group whose characteristics are different from those with an aneurysmal etiology. We present a retrospective longterm follow up of 60 patients, analyzing symptomatology, complications and evolution and identify a subgroup of patients with a perimesencephalic pattern (PMP) in computed tomography (CT) for their excellent prognosis. METHODS: We collected information on 60 patients admitted to our center between 1992 and 2000 and divided them into three groups, according to neuroimage: 26 had a PMP, 28 showed an aneurysmal pattern (AP), and 6 patients had normal TC, with complete arteriographic study. Length of follow-up was 6-24 months. RESULTS: All of the 26 patients with SAH and PPM pattern were rated grade I-II on the Hunt-Hess scale. None of them had complications during hospital stay and at long term, 22 (84%) were asymptomatic, while 4 (16%) reported cephalea. Out of 28 patients with SAH and AP, 22 were rated Hunt-Hess Scale grade I and II (78%), 5 grade III (18%) and one patient was rated grade IV. Rebleeding caused death in one of them, and two required drainage for hydrocephalia. A total of 68% (19 patients) were asymptomatic and the others complained of cephalea. CONCLUSIONS: We stress the good evolution of nonaneurysmal SAH at short and long term, especially those following a PMP with absence of complication.
INTRODUCTION: All stroke patients should receive the same degree of specialized healthcare attention according to the stage of their disease, independently of where they live, their age, gender or ethnicity. OBJECTIVE: To create an organized healthcare system able to offer the needed care for each patient, optimizing the use of the existing resource. METHODS: A committee of 14 neurologists specialized in neurovascular diseases representing different regions of Spain evaluated the available scientific evidence according to the published literature. RESULTS: During the acute phase, all stroke patients must be evaluated in hospitals that offer access to specialized physicians (neurologists) and the indicated diagnostic and therapeutic procedures. Hospitals that deliver care to acute stroke patients must be prepared to attend these patients and need to arrange a predefined transferring circuit coordinated with the extrahospitalary emergency service. Since resources are limited, they should be structured into different care levels according to the target population. Thus, three types of hospitals will be defined for stroke care: reference stroke hospital, hospital with stroke unit, hospital with stroke team.
BACKGROUND: In patients with cystic fibrosis (CF) neutrophils are recruited in excess to the airways yet pathogens are not cleared and the patients suffer from chronic infections. Recent studies have shown a deficiency in airway fluids from patients with CF and other inflammatory pulmonary conditions of surfactant protein A (SP-A), a pattern recognition molecule that facilitates uptake of microbes by macrophages and neutrophils. METHODS: In vitro simulations were used to test the hypothesis that decreased SP-A levels in CF might be the result of degradation by neutrophil serine proteases. RESULTS: Very low levels of the neutrophil granule serine proteases cathepsin G, elastase, and proteinase-3 rapidly degraded pure SP-A when tested in buffered saline. The order of potency was cathepsin G>elastase>proteinase-3. The addition of cathepsin G or elastase to normal bronchoalveolar lavage (BAL) fluid caused a dose dependent degradation of endogenous native SP-A. Cathepsin G and elastase were present in the BAL fluid from many patients with CF. Simple incubation of protease positive BAL fluid from patients with CF caused a time dependent degradation of added SP-A or, where present, endogenous SP-A. The degradation of SP-A by protease(s) in BAL fluid of patients with CF was abrogated by diisopropylfluorophosphate and monocyte/neutrophil elastase inhibitor. CONCLUSIONS: The findings strongly suggest that the neutrophil serine proteases cathepsin G and/or elastase and/or proteinase-3 contribute to degradation of SP-A and thereby diminish innate pulmonary antimicrobial defence.
Recovery from the debilitating effects of ischaemic stroke is variable and unpredictable. To maximize patient recovery, a greater understanding of the molecular mechanisms involved in regulating both apoptosis and the repair processes affecting neuronal protection, particularly in the penumbra region, is desirable. We have previously shown, in human subjects, the increased expression of several growth factors soon after stroke, together with appearance of tyrosine phosphorylated proteins, in particular mitogen activated protein (MAP) kinase (ERK1/2). In this paper, we demonstrate a relatively short-lasting (< 12 h), but substantial increase in expression of phosphorylated proteins, in particular, p-JNK (phosphorylated c-Jun N-terminal kinase) and p-ERK1/2 in both the grey matter penumbra and infarcted tissue of rats, following permanent middle cerebral artery occlusion. p-ERK1/2 was associated with neurones and endothelial cells in the vicinity of the infarct while p-JNK was mainly expressed in neurones. Expression of both p-MEK3/6 and p-p38 MAP kinase was also increased in neurones and astroglia, within 1 h of infarction, p-p38 remaining elevated and associated with neurones and in particular with astroglia in the penumbra region for > 4 days. Evidence suggests that short-term activation of these proteins may be detrimental to neuronal survival, while their transient nature makes them unlikely to support angiogenesis, revascularization and reperfusion over a period of days and weeks. On the other hand, short-medium-term up-regulation of neuronal p-JNK, p-c-Jun, p-Stat-1 and p-p38 might be a factor in the regulation of apoptosis. Therapeutic manipulation of phosphorylation/activation of these and other important signalling intermediates might form the basis of an appropriate treatment to maximize revascularization and neuronal protection after ischaemic stroke.
Plant K(+) transporters of the HAK family belong to four rather divergent phylogenetic clusters, although most of the transporters belong to clusters I or II. A simple phylogenetic analysis of fungal and plant HAK transporters suggests that an original HAK gene duplicated even before fungi and plants diverged, generating transporters that at present fulfill different functions in the plant. The HvHAK1 transporter belongs to cluster I and mediates high-affinity K(+) uptake in barley roots, but no function is known for the cluster II transporter, HvHAK2, which is not functional in yeast. The function of HvHAK2 was investigated by constructing HvHAK1-HAK2 chimeric transporters, which were not functional even when they included only short fragments of HvHAK2. Then, amino acids characteristic of cluster II in the N terminus and in the first transmembrane domain were introduced into HvHAK1. All of these changes increased the Rb(+) K(m), introducing minimal changes in the Na(+) K(m), which suggested that HvHAK2 is a low-affinity, Na(+)-sensitive K(+) transporter. Using a K(+)-defective Escherichia coli mutant, we functionally expressed HvHAK2 and found that the predicted characteristics were correct, as well as discovering that the bacterial expression of HvHAK2 is functional at pH 5.5 but not at 7.5. We discuss whether HvHAK2 may be a tonoplast transporter effective for vacuolar K(+) depletion in K(+) starved plants.
This paper describes work being undertaken as part of the IERAPSI (Integrated Environment for the Rehearsal and Panning of Surgical Intervention) project. The project is focussing on surgery for the petrous bone, and brings together a consortium of European clinicians and technology providers working in this field. The paper presents the results of a comprehensive user task analysis that has been carried out in the first phase of the IERAPSI project, and details the current status of development of a pre operative planning environment and a physically-based surgical simulator.
We examined expression of vascular endothelial growth factor (VEGF), phosphorylation of mitogen activated protein kinase (MAP) kinase (ERK1 and ERK2) and tyrosine phosphorylation in 19 patients (aged 58-90 years; mean 75) who died 1-44 days after acute ischaemic stroke. In the grey matter penumbra, 13 of 19 patients showed an increase in MAP kinase tyrosine phosphorylation (ERK1; 2.0- to 8-fold, ERK2; 2.2- to 11-fold) compared with normal contralateral tissue. In almost all cases, ERK-2 phosphorylation was higher than ERK1. Of these 13 patients, 11 also showed a general increase in tyrosine kinase phosphorylation, and eight expressed increased levels of VEGF protein (2.5- to 5-fold). In tissue examined directly from the infarct core, activation of the above proteins was not observed in the, majority of patients. In the white matter, seven of 19 patients (penumbra), and nine of 19 patients (stroke) had an increase in MAP kinase tyrosine phosphorylation (ERK1; 2.0- to 4.6-fold and ERK-2; 2.3- to 5.4-fold respectively) compared with normal contralateral tissue. There was no relationship between activation of MAP kinase and expression of VEGF. Examination of phosphorylated MAP kinase by immunohistochemistry revealed an increase in immunoreactivity in neurones, astroglial cells, reactive microglia and endothelial cells in areas surrounding infarcts, especially in areas with the highest density of microvessels. In conclusion, chronic activation of tyrosine phosphorylated events, in particular redistribution and phosphorylation of MAP kinase (ERK1/ERK2) occurs consistently in the grey matter penumbra of brain tissue following ischaemic stroke, and may be associated with increase in expression of VEGF. These signal transduction events could be important determinants of the extent of neuronal survival and/or angiogenic activity in the recovering brain tissue.
The Na(+)-K(+) co-transporter HKT1, first isolated from wheat, mediates high-affinity K(+) uptake. The function of HKT1 in plants, however, remains to be elucidated, and the isolation of HKT1 homologs from Arabidopsis would further studies of the roles of HKT1 genes in plants. We report here the isolation of a cDNA homologous to HKT1 from Arabidopsis (AtHKT1) and the characterization of its mode of ion transport in heterologous systems. The deduced amino acid sequence of AtHKT1 is 41% identical to that of HKT1, and the hydropathy profiles are very similar. AtHKT1 is expressed in roots and, to a lesser extent, in other tissues. Interestingly, we found that the ion transport properties of AtHKT1 are significantly different from the wheat counterpart. As detected by electrophysiological measurements, AtHKT1 functioned as a selective Na(+) uptake transporter in Xenopus laevis oocytes, and the presence of external K(+) did not affect the AtHKT1-mediated ion conductance (unlike that of HKT1). When expressed in Saccharomyces cerevisiae, AtHKT1 inhibited growth of the yeast in a medium containing high levels of Na(+), which correlates to the large inward Na(+) currents found in the oocytes. Furthermore, in contrast to HKT1, AtHKT1 did not complement the growth of yeast cells deficient in K(+) uptake when cultured in K(+)-limiting medium. However, expression of AtHKT1 did rescue Escherichia coli mutants carrying deletions in K(+) transporters. The rescue was associated with a less than 2-fold stimulation of K(+) uptake into K(+)-depleted cells. These data demonstrate that AtHKT1 differs in its transport properties from the wheat HKT1, and that AtHKT1 can mediate Na(+) and, to a small degree, K(+) transport in heterologous expression systems.
Potassium is an important macronutrient required for plant growth, whereas sodium (Na+) can be toxic at high concentrations. The wheat K+ uptake transporter HKT1 has been shown to function in yeast and oocytes as a high affinity K+-Na+ cotransporter, and as a low affinity Na+ transporter at high external Na+. A previous study showed that point mutations in HKT1, which confer enhancement of Na+ tolerance to yeast, can be isolated by genetic selection. Here we report on the isolation of mutations in new domains of HKT1 showing further large increases in Na+ tolerance. By selection in a Na+ ATPase deletion mutant of yeast that shows a high Na+ sensitivity, new HKT1 mutants at positions Gln-270 and Asn-365 were isolated. Several independent mutations were isolated at the Asn-365 site. N365S dramatically increased Na+ tolerance in yeast compared with all other HKT1 mutants. Cation uptake experiments in yeast and biophysical characterization in Xenopus oocytes showed that the mechanisms underlying the Na+ tolerance conferred by the N365S mutant were: reduced inhibition of high affinity Rb+ (K+) uptake at high Na+ concentrations, reduced low affinity Na+ uptake, and reduced Na+ to K+ content ratios in yeast. In addition, the N365S mutant could be clearly distinguished from less Na+-tolerant HKT1 mutants by a markedly decreased relative permeability for Na+ at high Na+ concentrations. The new mutations contribute to the identification of new functional domains and an amino acid in a loop domain that is involved in cation specificity of a plant high affinity K+ transporter and will be valuable for molecular analyses of Na+ transport mechanisms and stress in plants.
Two Neurospora crassa genes, trk-1 and hak-1, encode K+ transporters that show sequence similarities to the TRK transporters described in Saccharomyces cerevisiae and Schizosaccharomyces pombe, and to the HAK transporters described in Schwanniomyces occidentalis and barley. The N. crassa TRK1 and HAK1 transporters expressed by the corresponding cDNAs in a trk1 delta trk2 delta mutant of S. cerevisiae exhibited a high affinity for Rb+ and K+. Northern blot analysis and comparison of the kinetic characteristics of the two transporters in the trk1 delta trk2 delta mutant with the kinetic characteristics of K+ uptake in N. crassa cells allowed TRK1 to be identified as the dominant K+ transporter and HAK1 as a transporter that is only expressed when the cells are K+ starved. The HAK1 transporter showed a high concentrative capacity and is identified as the K(+)-H+ symporter described in N. crassa, whereas TRK1 might be a K+ uniporter. Although the co-existence of K+ transporters of the TRK and HAK types in the same species had not been reported formerly, we discuss whether this co-existence may be the normal situation in soil fungi.
A series of untrained, healthy, obese women (body mass index 32.5 +/- 0.9 kg.m-2) were subjected to a protocol of intense exercise on a cycloergometer and compared with lean controls (body mass index 20. 9 +/- 0.5 kg.m-2). Physiological parameters, blood lactate, bicarbonate, plasma metabolites, oxygen consumption and CO2 production were measured. Impedance-derived extracellular water and plasma changes in lactate and bicarbonate were used to determine changes in bicarbonate pools and lactate-displaced CO2. From these and respiratory gases, the respiratory quotient was calculated and thence overall fuel consumption. Anaerobic energy during exercise accounted for about 1.8% of all energy consumed in the lean but only 0.7% in the obese. Obese women fatigued at lower workloads and energy expenditure levels than did the lean, and their lactate buildup was similar when compared on the basis of fat-free mass. The data support the postulation of fatigue being triggered by a combination of factors: stretched cardiovascular work would be the main factor for obese women, in part limiting lactate production. For lean women, the triggering factor for fatigue could be the loss of buffering capacity; but it is the combination of stretching cardiovascular capacity, exhaustion of glycogen and available glucose and increase in lactate/loss of bicarbonate buffer that determines the onset of fatigue.
High-affinity K+ uptake in plant roots is rapidly up-regulated when K+ is withheld and down-regulated when K+ is resupplied. These processes make important contributions to plant K+ homeostasis. A cDNA coding for a high-affinity K+ transporter, HKT1, was earlier cloned from wheat (Triticum aestivum L.) roots and functionally characterized. We demonstrate here that in both barley (Hordeum vulgare L.) and wheat roots, a rapid and large up-regulation of HKT1 mRNA levels resulted when K+ was withdrawn from growth media. This effect was specific for K+; withholding N caused a modest reduction of HKT1 mRNA levels. Up-regulation of HKT1 transcript levels in barley roots occurred within 4 h of removing K+, which corresponds to the documented increase of high-affinity K+ uptake in roots following removal of K+. Increased expression of HKT1 mRNA was evident before a decline in total root K+ concentration could be detected. Resupply of 1 mM K+ was sufficient to strongly reduce HKT1 transcript levels. In wheat root cortical cells, both membrane depolarizations in response to 100 &mgr;M K+, Cs+, and Rb+, and high-affinity K+ uptake were enhanced by K+ deprivation. Thus, in both plant systems the observed physiological changes associated with manipulating external K+ supply were correlated with levels of HKT1 mRNA expression. Implications of these findings for K+ sensing and regulation of the HKT1 mRNA levels in plant roots are discussed.
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INTRODUCTION: Behçet disease is a systemic form of vasculitis which presents with neurological symptoms with a frequency varying between 16 and 40%. Involvement of the parenchyma has been found to worsen the prognosis in patients with neuroBehçet (NB). OBJECTIVE: To review the clinical features and course of patients with NB involving the parenchyma of the central nervous system (CNS). CLINICAL CASES: Seven patients with Behçet disease and neurological localizing signs were seen in our hospital between 1989 and 1996. The initial diagnosis was of ischemic ictus in five of the seven patients. Both neuroimaging studies and investigation of the cerebrospinal fluid were always pathological in all cases. Vascular studies (arteriography and echo-Doppler of the supra-aortic trunks) were normal. One patient died. Four patients had serious sequelae following treatment. CONCLUSION: NB should be included in the different diagnosis of ictus. Involvement of the parenchyma of the CNS was accompanied by lymphocytic meningitis, perhaps also leading to a worse functional prognosis.
INTRODUCTION: Purely bulbar hematomas are not common (0.25%-0.50% of all intraparenchymatous hematomas), probably because of the particular characteristics of the anatomy and hemodynamics of the bulbar circulation. CLINICAL CASES: We selected 18 cases. Three of these were our own and the purely bulbar localization was confirmed by neuroimaging surgical findings and necropsy. Its appearance was related to arterial hypertension, anticoagulant treatment and obvious or occult vascular malformations, although in a considerable proportion (39%) no cause was found. Although arterial hypertension is less important in its etiopathogenesis as compared with other sites of intraparenchymatous hemorrhage, 7 of the patients were hypertensive. The commonest clinical findings were nystagmus (72%), and dysphagia and hypoglossal paralysis (61%). The commonest site was posterior. Arteriography was of little use since this was normal in all the cases in which it was done (72%). The presence of angiographically occult malformations made it advisable to use magnetic resonance and repeat this after the acute phase. Three quarters of the patients were treated medically. Mortality (22%) was lower than the overall rate for posterior fossa hematomas, and the prognosis was better since no survivors had incapacitating sequelae. CONCLUSION: The specific etiopathogeneses, clinical characteristics and course of bulbar hematomas makes it advisable to do a differential study regarding other types of intracerebral hemorrhage.
The high-affinity K+ uptake system of plants plays a crucial role in nutrition and has been the subject of extensive kinetic studies. However, major components of this system remain to be identified. We isolated a cDNA from barley roots, HvHAK1, whose translated sequence shows homology to the Escherichia coli Kup and Schwanniomyces occidentalis HAK1 K+ transporters. HvHAK1 conferred high-affinity K+ uptake to a K(+)-uptake-deficient yeast mutant exhibiting the hallmark characteristics of the high-affinity K+ uptake described for barley roots. HvHAK1 also mediated low-affinity Na+ uptake. Another cDNA (HvHAK2) encoding a polypeptide 42% identical to HvHAK1 was also isolated. Analysis of several genomes of Triticeae indicates that HvHAK1 belongs to a multigene family. Translated sequences from bacterial DNAs and Arabidopsis, rice, and possibly human cDNAs show homology to the Kup-HAK1-HvHAK1 family of K+ transporters.