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Díaz-Corrales FJ, Colasante C, Contreras Q, Puig M, Serrano JA, Hernández L, Beaman BL. Nocardia otitidiscaviarum (GAM-5) induces parkinsonian-like alterations in mouse. Braz J Med Biol Res 2004; 37:539-48. [PMID: 15064817 DOI: 10.1590/s0100-879x2004000400011] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Parkinson's disease, a major neurodegenerative disorder in humans whose etiology is unknown, may be associated with some environmental factors. Nocardia otitidiscaviarum (GAM-5) isolated from a patient with an actinomycetoma produced signs similar to Parkinson's disease following iv injection into NMRI mice. NMRI mice were infected intravenously with a non-lethal dose of 5 x 10(6) colony forming units of N. otitidiscaviarum (GAM-5). Fourteen days after bacterial infection, most of the 60 mice injected exhibited parkinsonian features characterized by vertical head tremor, akinesia/bradykinesia, flexed posture and postural instability. There was a peak of nocardial growth in the brain during the first 24 h followed by a decrease, so that by 14 days nocardiae could no longer be cultured. At 24 h after infection, Gram staining showed nocardiae in neurons in the substantia nigra and occasionally in the brain parenchyma in the frontal and parietal cortex. At 21 days post-infection, tyrosine hydroxylase immunolabeling showed a 58% reduction of tyrosine hydroxylase in the substantia nigra, and a 35% reduction of tyrosine hydroxylase in the ventral tegmental region. Dopamine levels were reduced from 110 +/- 32.5 to 58 +/- 16.5 ng/mg protein (47.2% reduction) in brain from infected mice exhibiting impaired movements, whereas serotonin levels were unchanged (191 +/- 44 protein in control and 175 +/- 39 ng/mg protein in injected mice). At later times, intraneuronal inclusion bodies were observed in the substantia nigra. Our observations emphasize the need for further studies of the potential association between Parkinson's disease or parkinsonism-like disease and exposure to various nocardial species.
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Díaz-Aparicio E, Hernández L, Suárez-Güemes F. Protection against Brucellosis in Goats, Five Years after Vaccination with Reduced-Dose Brucella melitensis Rev 1 Vaccine. Trop Anim Health Prod 2004; 36:117-21. [PMID: 14998310 DOI: 10.1023/b:trop.0000012106.84833.3b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The protection conferred by the reduced-dose Rev 1 Brucella melitensis vaccine in goats that had been immunized 5 years previously was evaluated. Sixteen goats vaccinated 5 years before with Rev 1 (1 x 10(5) cfu) and 5 non-vaccinated goats were challenged with B. melitensis 16M (4 x 10(5) cfu) using the conjunctival route. After giving birth or aborting, the goats were sacrificed and tissue samples were taken for bacteriological study. The challenge strain was recovered in 12%, of the animals from the vaccinated group, and in (80% of the control group. It is concluded, therefore that the use of reduced-dose Rev 1 protects goats vaccinated in endemic areas for at least 5 years after immunization.
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González MC, Díaz-Golpe V, Hernández L, Martin S, Fernández F. [Unusual molecular changes in two families with Friedreich's ataxia]. Neurologia 2003; 18:392-5. [PMID: 14505249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023] Open
Abstract
Friedreich's ataxia is an autosomal recessive disease generally characterized by the presence of microsatellite expansion in a GAA triplet. The patients inherit a pathologic allele from each one of their parents, that may sometimes show GAA triplet expansions or contractions. Two familial studies of typical Friedreich's ataxia are described. Their molecular study demonstrated marked intergenerational instability and an abnormally long expansion of the GAA triplet in the father in the other one. In the first case, there were expansions of 680/815 repetitions, being characterized by an expansion of 290 repetitions GAA in the father-patient transmission. The second case presented GAA of 1,260/1,095 expansions, while the expanded allele of the father was 1,350 repetitions. These cases illustrate that there can be both expansion as well as contraction of the GAA triplet from alleles of paternal origin in the disease, without any apparent phenotypic changes.
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Hernández L, Hernández P, Velasco V. Carbon felt electrode design: application to phenol electrochemical determination by direct oxidation. Anal Bioanal Chem 2003; 377:262-6. [PMID: 12830358 DOI: 10.1007/s00216-003-2022-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2003] [Revised: 04/26/2003] [Accepted: 04/29/2003] [Indexed: 10/26/2022]
Abstract
In this paper, electrochemical behaviour of phenol in a carbon felt electrode is studied. An adsorption process on electrode surface that inhibits polymer formation after oxidation of phenol was confirmed. In this work we propose a phenol determination method based on direct electrochemical oxidation on carbon felt electrodes after an accumulation process.
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Páez X, Hernández L, Baptista T. [Advances in the molecular treatment of depression]. Rev Neurol 2003; 37:459-70. [PMID: 14533097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
AIMS The objective of this study is to survey present and future antidepressant drug therapy based on the progress made in the field of biotechnology. DEVELOPMENT The simplistic and mistaken view that one single system of neurotransmission is altered in depression and that there is, therefore, just one single treatment has changed. Molecular biology and Genetics have enabled us to determine other possible chemical alterations in the brain, beyond the sole participation of the monoaminergic modulation systems, which is the classical hypothesis. In this paper we describe the evidence for the relations between depression and the therapeutic effect the classical antidepressants have on: 1. The peptidergic system of the corticotropin-releasing hormone, cortisol and the functional state of its receptors; 2. Intracellular signalling systems such as cAMP on transcription factors like CREB and neurotrophins; 3. The immune system and cytosines; 4. Glutamate transmission; and 5. The neuropeptidergic system of substance P, neuroactive steroids and the neuroglia. This has allowed other biochemical hypotheses about depression and the possibility of new treatments to be put forward. CONCLUSIONS We are still not certain about the exact cause or the processes that determine mental illnesses such as depression or how improvements are achieved with the antidepressants we currently have available. Nevertheless, biotechnology is expected to be a great help in advancing towards a better understanding of the interrelations between the nervous, immune and endocrine systems, with their intracellular cascades and final outcomes in genetic expression and protein function, in depression. This will enable more efficient, more selective and faster-acting drugs to be developed and, in the future and with the help of psychogenomics, even make it possible to produce tailor-made medication for each patient.
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Molina M, Hernández L, Duran J, Farré R, Rubio R, Navajas D, Montserrat JM. Protocolo para evaluar una CPAP automática. Valoración de la utilidad del Autoset-T para determinar la presión de CPAP óptima en el síndrome de apnea-hipopnea del sueño. Arch Bronconeumol 2003. [DOI: 10.1157/13044151] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Molina M, Hernández L, Duran J, Farré R, Rubio R, Navajas D, Montserrat JM. [Protocol to evaluate automatic continuous positive airway pressure. Assessment of the usefulness of the Autoset-T device to determine optimal pressure for treating sleep apnea/hypopnea syndrome]. Arch Bronconeumol 2003; 39:118-25. [PMID: 12622971 DOI: 10.1016/s0300-2896(03)75338-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Given the high prevalence of sleep apnea/hypopnea syndrome (SAHS) and great demand for conventional polysomnography (PSG) and long waiting lists, alternative means for diagnosing SAHS and titrating continuous positive airway pressure (CPAP) are needed. Automatic CPAP may play a role in meeting the last objective, not only for treatment but also for suggesting the optimum CPAP setting. OBJECTIVES a) To define a protocol to assess the functioning of an automatic CPAP device by means of a mechanical model; b) to determine the behavior of automatically adjusted CPAP during PSG; c) to define the usefulness of automatic CPAP for indicating optimal CPAP pressure for patients with SAHS; d) to evaluate the efficacy of the automatically indicated pressure setting against conventional PSG. METHODS Four protocols were carried out using the Autoset-T (AT) device. 1. Apneas, hypopneas, flow limitation, snoring and normal flow were simulated in a laboratory using a mechanical model in order to check AT functioning. 2. The behavior of the automatically adjusted CPAP was observed in real time during PSG in 12 patients with severe SAHS. 3. The agreement of CPAP titrated with the AT and with PSG was checked in a group of 39 patients with SAHS. 4. The efficacy of the CPAP pressure recommended by the AT was checked by PSG in a group of 14 patients with SAHS. RESULTS With the AT, CPAP increased rapidly in response to apneas or snoring in the mechanical model and during conventional PSG; it took only a mean 2.8 3.1 min to rise from a baseline pressure of 4 cm H2O to a near-optimum pressure of 11 1 cm H2O. Once normal flow was reached CPAP slowly decreased, responding with great sensitivity to the slightest abnormality, especially snoring, but not changing in response to certain types of flow limitation. The pressure read visually on the AT was similar to the one recommended by PSG in most of the 39 patients (71%). The PSG performed after one month of using AT-recommended CPAP titration confirmed that the number of apneas, hypopneas (apnea/hypopnea index 6(1) and arousals (8 2) was normal for these SAHS patients. CONCLUSIONS The AT increases pressure rapidly in the presence of respiratory events and maintains a normal breathing pattern in most patients. Visual reading of the AT pressure allows correct identification of the optimal CPAP setting for SAHS treatment.
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Cobo F, Martínez A, Pinyol M, Hernández L, Gómez M, Beá S, Esteve J, Rozman M, Bosch F, López-Guillermo A, Montserrat E, Campo E. Multiple cell cycle regulator alterations in Richter's transformation of chronic lymphocytic leukemia. Leukemia 2002; 16:1028-34. [PMID: 12040434 DOI: 10.1038/sj.leu.2402529] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2001] [Accepted: 12/13/2001] [Indexed: 11/09/2022]
Abstract
To investigate the role of the cell cycle regulators p21(Waf1), p27(Kip1), retinoblastoma (Rb), and cyclin D1 in Richter's transformation of chronic lymphocytic leukemia (CLL), we analyzed 19 CLL and eight Richter's syndrome (RS) tumors, previously characterized for p53 and ARF/INK4a abnormalities. p21(Waf1)immunohistochemical expression was negative in 12 of 15 CLL (80%), whereas it was moderate or strong in three of seven RS (43%). p21(Waf1) gene was in germline configuration in all the tumors analyzed. Four immunohistochemical patterns of p53 and p21(Waf1) expression were observed: (1) p53-/p21- in 10 of 15 CLL (67%), but only in two of six RS (33%); (2) p53+/p21+ in three CLL (20%) and two RS (33%); (3) p53-/p21+ in one RS; and (4) p53++/p21- in two CLL and one RS. Two p53+/p21+ CLL evolved into RS. p53 mutations clustered around the p53++/p21- (two CLL and one RS) and p53-/p21- (one CLL and one RS) tumors. While the majority of CLL displayed strong p27 immunoreactivity, RS tumors were constantly p27-negative. p27(Kip1) gene was in germline configuration in all the tumors analyzed. Most CLL cases were negative for Rb expression. In contrast, all RS exhibited strong Rb expression. Cyclin D1 overexpression was only detected in one CLL evolving into RS and one RS. In conclusion, a p53+/p21- immunohistochemical pattern is shown exclusively by p53-mutated CLL/RS. Additionally, our results suggest a possible implication of moderate/strong p21(Waf1) expression, loss of p27 expression, and cyclin D1 overexpression in the Richter's transformation of CLL.
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MESH Headings
- Adult
- Aged
- Cell Cycle
- Cell Cycle Proteins/metabolism
- Cyclin D1/metabolism
- Cyclin-Dependent Kinase Inhibitor p21
- Cyclin-Dependent Kinase Inhibitor p27
- Cyclins/metabolism
- Female
- Genes, p53
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/diagnosis
- Leukemia, Lymphocytic, Chronic, B-Cell/genetics
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Lymphoma, Large B-Cell, Diffuse/diagnosis
- Lymphoma, Large B-Cell, Diffuse/genetics
- Lymphoma, Large B-Cell, Diffuse/metabolism
- Male
- Middle Aged
- Mutation
- Retinoblastoma Protein/metabolism
- Tumor Suppressor Proteins/metabolism
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Hernández L, Ramírez R, Hormaza JV, Madrazo J, Arrieta J. Increased levansucrase production by a genetically modified
Acetobacter diazotrophicus
strain in shaking batch cultures. Lett Appl Microbiol 2002. [DOI: 10.1046/j.1365-2672.1999.00470.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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85
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Hernanz R, Marín J, Hernández L, Salaices M, Redondo J, Alonso MJ. University of Wisconsin solution increases hyperpolarizing mechanisms in response to bradykinin. J Heart Lung Transplant 2001; 20:1317-24. [PMID: 11744416 DOI: 10.1016/s1053-2498(01)00342-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND The aim of this study was to determine the effect of University of Wisconsin solution (UWS) incubation on bradykinin-induced vasodilation. METHODS Porcine coronary arteries were incubated in Krebs-Henseleit solution (KHS) or UWS at 4 degrees C for 20 hours. Endothelium-dependent relaxation to bradykinin and endothelium-independent relaxation to nitric oxide were tested after U46619 or KCl pre-contraction. Nitric oxide synthase activity and protein expression was determined by [3H]-L-citrulline formation and western blot analysis, respectively. RESULTS The relaxation to bradykinin (0.1 to 300 nmol/liter) after U46619 (30 to 300 nmol/liter) pre-contraction was similar with both KHS and UWS pre-incubation; however, it was reduced after KCl pre-contraction (15 to 20 mmol/liter), this reduction being greater after UWS incubation. The inhibitory effect of N(G)-nitro-L-arginine methylester (0.1 mmol/liter) on bradykinin-induced relaxation was lower in UWS- than KHS-incubated segments after U46619 pre-contraction, but similar after KCl pre-contraction; however, the inhibitory effect of 0.5 mmol/liter ouabain was unaffected. Tetraethylammonium (5 mmol/liter) reduced the response to bradykinin more strongly after UWS pre-incubation. UWS did not modify relaxation to nitric oxide (0.1 to 30 micromol/liter) in pre-incubated UWS or KHS segments. UWS failed to modify both total nitric oxide synthase activity and endothelial nitric oxide synthase expression. CONCLUSIONS UWS incubation decreased nitric oxide participation and increased the hyperpolarizing mechanisms produced by bradykinin.
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Baptista T, Lacruz A, Angeles F, Silvera R, de Mendoza S, Mendoza MT, Hernández L. Endocrine and metabolic abnormalities involved in obesity associated with typical antipsychotic drug administration. PHARMACOPSYCHIATRY 2001; 34:223-31. [PMID: 11778142 DOI: 10.1055/s-2001-18034] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In this study, the authors assessed the endocrine system and glucose tolerance in obese and non-obese women chronically treated with typical antipsychotic drugs (AP). In particular, we tested the hypotheses that these subjects display hypogonadism and increased insulin resistance compared to healthy weight-matched controls, as these abnormalities create a tendency towards excessive body weight gain. Twenty-six AP-treated women were matched with 26 healthy women by age, body mass index and day of the menstrual cycle. The following serum variables were evaluated in each subject: glucose tolerance after an oral glucose overload, insulin, leptin, beta-endorphin, reproductive hormones, adrenal steroids and lipids. Compared to controls, AP-treated women displayed significantly higher levels of basal glucose, insulin after 60 min of the glucose overload, prolactin, thyroid stimulating hormone and beta-endorphin, with lower levels of C-Peptide, progesterone, 17-OH progesterone, androstenedione and high-density lipoprotein cholesterol. The levels of estradiol, estrone and leptin did not differ between the groups. Thus, women treated with typical AP appeared to display more insulin resistance than healthy controls, predisposing them to excessive weight gain. Insulin sensitivity might be further impaired when the subject switches to atypical AP administration. Metformin and related agents may reduce body weight in these subjects. The high levels of the opiate beta-endorphin suggest that opiate antagonists such as naloxone and naltrexone might be useful as well. Even though the luteal phase of the menstrual cycle appears to be severely disturbed, the normal serum levels of estradiol and estrone do not support the proposal derived from animal experimental studies about the use of estrogens or tamoxifen to counteract AP-induced obesity.
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Páez X, Hernández L. Biomedical applications of capillary electrophoresis with laser-induced fluorescence detection. Biopharm Drug Dispos 2001; 22:273-89. [PMID: 11835251 DOI: 10.1002/bdd.277] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Capillary electrophoresis (CE) is a high-efficiency analytical technique that has had a great impact as a tool in biomedical research, clinical and forensic practice in the last ten years. Only in one of the applications, the DNA analysis, it has had an explosive exponential growth in the last few years. This impact is expressed in an enormous amount of CE articles and many reviews. The CE advantages with respect to other analytical techniques: the required very small sample volume, rapid analysis, great resolution power and low costs, have made this technique ideal for the analysis of a numerous endogenous and exogenous substances present in biological fluids. The different modes of CE have been coupled to different detection techniques such as UV-absorbance, electrochemical, mass spectrometry and laser-induced fluorescence detection (LIFD) to detect different nature and molecular size separated analytes. This review focuses mostly on the applications of CE-LIFD, to measure drugs and endogenous neuroactive substances such as amino acids and monoamines, especially in microdialysis samples from experimental animals and humans. CE-LIFD trends are discussed: automated faster analysis with capillary array systems, resolution power improvement, higher detection sensitivity, and CE systems miniaturization for extremely small sample volume, in order to make CE easier and affordable to the lab bench or the clinical bed.
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Romero-Candeira S, Fernández C, Martín C, Sánchez-Paya J, Hernández L. Influence of diuretics on the concentration of proteins and other components of pleural transudates in patients with heart failure. Am J Med 2001; 110:681-6. [PMID: 11403751 DOI: 10.1016/s0002-9343(01)00726-4] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE Diuretic therapy increases the total protein and lactate dehydrogenase concentrations in pleural fluid in patients with transudates due to heart failure, but the effect of diuresis on other substances in pleural fluid constituents is not known. SUBJECTS AND METHODS Twenty-one patients with transudative pleural effusions due to congestive heart failure were prospectively studied. Repeated diagnostic thoracentesis (mean +/- SD = 3 +/- 1; range, 2 to 6) was performed until the effusions were radiographically unapparent (5 +/- 2 days). Thirty-one patients with congestive heart failure who underwent only a single thoracentesis after diuretic therapy served as controls. We measured the concentrations of various components of pleural effusions in the serum and in the pleural fluid, and determined the serum-pleural fluid gradient (serum concentration minus pleural fluid concentration) and ratio (serum concentration divided by pleural fluid concentration). RESULTS The pleural concentrations of most components increased significantly (P <0.001) from the initial specimen to the final specimen: total protein, from 23 +/- 7 g/L to 33 +/- 9 g/L; albumin, from 13 +/- 4 g/L to 18 +/- 6 g/L; lactate dehydrogenase, from 177 +/- 62 U/L to 288 +/- 90 U/L; cholesterol, from 31 +/- 16 mg/dL to 52 +/- 22 mg/dL; and cholinesterase, from 1,304 +/- 616 U/L to 1,884 +/- 674 U/L. Expressed as percentage change, the increases in the serum-pleural fluid gradients for albumin (12% +/- 22%) and total protein (11% +/- 12%) were significantly less than the increases in their concentrations in pleural fluid (albumin, 47% +/- 49%; total protein, 48% +/- 40%) or in their pleural fluid/serum ratios (albumin, 27% +/- 29%; total protein, 38% +/- 34%). CONCLUSIONS The concentrations of the biochemical components commonly measured in pleural fluid increase progressively during diuretic therapy. Calculation of the serum-pleural fluid gradients for protein and albumin may be the most useful way to distinguish transudates from exudates in patients with congestive heart failure who have undergone diuresis.
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Vilalta J, Hernández L, Pérez L, Pareras L, Guitart JM, Rubio E. [Distal aneurysms of the vertebrobasilar system. A report of five cases]. Rev Neurol 2001; 32:915-8. [PMID: 11424045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
INTRODUCTION Aneurysms distal to the circle of Willis are uncommon. Among the rarest of such aneurysms are those found in the territory of the vertebrobasilar artery. OBJECTIVE To describe clinico-radiological aspects and the clinico-surgical evolution of five patients with distal aneurysms of the cerebellar arteries. PATIENTS AND METHODS Five patients (2.5%), with aneurysms of the cerebellar arteries, of a total of 194 patients with cerebral aneurysms admitted to our hospital between 1995 and 1998. RESULTS All patients presented with subarachnoid hemorrhage. One patient also had an arteriovenous malformation (AVM). One patient refused surgical treatment, three were treated surgically and one using the endovascular approach. The patient who was successfully treated using the endovascular approach to an aneurysm of the antero-inferior cerebellar artery, and who also had an AVM had a further episode of bleeding following partial embolization of his AVM. The patients who were treated surgically and the one who refused surgical treatment made good progress. CONCLUSIONS A multidisciplinary approach to the treatment of cerebral aneurysms is essential. Microsurgical techniques are very useful, especially in peripheral aneurysms.
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Hernández S, Bessa X, Beà S, Hernández L, Nadal A, Mallofré C, Muntane J, Castells A, Fernández PL, Cardesa A, Campo E. Differential expression of cdc25 cell-cycle-activating phosphatases in human colorectal carcinoma. J Transl Med 2001; 81:465-73. [PMID: 11304565 DOI: 10.1038/labinvest.3780254] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
cdc25 is a family of cell-cycle phosphatases that activate the cyclin-dependent kinases. cdc25A and B, but not C, have oncogenic potential in vitro. In this study, we analyzed the possible implication of cdc25 genes in the progression of colorectal tumors. RNA and DNA were extracted from 34 paired tumor and normal colorectal tissues and examined by Northern blot, RT-PCR, and Southern blot, respectively. Protein expression was analyzed by Western blot in a subset of normal and tumor samples. The expression levels were correlated with the clinicopathologic characteristics and survival of the patients. cdc25B mRNA was overexpressed in 19 carcinomas (56%). A significant correlation was observed between high cdc25B mRNA levels and the relapse-free, overall, and cancer-related survival of the patients. The cdc25B2 splicing variant was detected in 27 carcinomas (79%) but only in 9 normal samples (26%) and was associated with the grade of the differentiation of the tumors. cdc25A mRNA was overexpressed in four tumors (12%) and cdc25C1 mRNA was overexpressed in nine tumors (26%). A new cdc25C2 splicing variant lacking exon 4 and 5 was identified in all of the tumors and in 56% of the normal samples. No amplifications or gene rearrangements of these genes were detected. In conclusion, these findings indicate that cdc25 isoforms and splicing variants are differentially regulated in colorectal carcinomas and may participate in the development of these tumors. Additionally, the correlation between cdc25B mRNA levels and the survival of the patients also suggest that the cdc25B isoform may be involved in the progression of the disease.
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Beà S, Tort F, Pinyol M, Puig X, Hernández L, Hernández S, Fernandez PL, van Lohuizen M, Colomer D, Campo E. BMI-1 gene amplification and overexpression in hematological malignancies occur mainly in mantle cell lymphomas. Cancer Res 2001; 61:2409-12. [PMID: 11289106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The BMI-1 gene is a putative oncogene belonging to the Polycomb group family that cooperates with c-myc in the generation of mouse lymphomas and seems to participate in cell cycle regulation and senescence by acting as a transcriptional repressor of the INK4a/ARF locus. The BMI-1 gene has been located on chromosome 10p13, a region involved in chromosomal translocations in infant leukemias, and amplified in occasional non-Hodgkin's lymphomas (NHLs) and solid tumors. To determine the possible alterations of this gene in human malignancies, we have examined 160 lymphoproliferative disorders, 13 myeloid leukemias, and 89 carcinomas by Southern blot analysis and detected BMI-1 gene amplification (3- to 7-fold) in 4 of 36 (11%) mantle cell lymphomas (MCLs) with no alterations in the INK4a/ARF locus. BMI-1 and p16INK4a mRNA and protein expression were also studied by real-time quantitative reverse transcription-PCR and Western blot, respectively, in a subset of NHLs. BMI-1 expression was significantly higher in chronic lymphocytic leukemia and MCL than in follicular lymphoma and large B cell lymphoma. The four tumors with gene amplification showed significantly higher mRNA levels than other MCLs and NHLs with the BMI-1 gene in germline configuration. Five additional MCLs also showed very high mRNA levels without gene amplification. A good correlation between BMI-1 mRNA levels and protein expression was observed in all types of lymphomas. No relationship was detected between BMI-1 and p16INK4a mRNA levels. These findings suggest that BMI-1 gene alterations in human neoplasms are uncommon, but they may contribute to the pathogenesis in a subset of malignant lymphomas, particularly of mantle cell type.
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Trujillo LE, Arrieta JG, Dafhnis F, García J, Valdés J, Tambara Y, Pérez M, Hernández L. Fructo-oligosaccharides production by the Gluconacetobacter diazotrophicus levansucrase expressed in the methylotrophic yeast Pichia pastoris. Enzyme Microb Technol 2001; 28:139-144. [PMID: 11166804 DOI: 10.1016/s0141-0229(00)00290-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Levansucrase (LsdA) (EC 2.4.1.10) from Gluconacetobacter diazotrophicus (formerly Acetobacter diazotrophicus) yields high levels of fructo-oligosaccharides (FOS) from sucrose. A DNA fragment encoding the precursor LsdA lacking the first 57 amino acids was fused to the pho1 signal sequence under the control of the Pichia pastoris-alcohol oxidase 1 (AOX1) promoter. Methanol induction of a P. pastoris strain harboring a single copy of the lsdA expression cassette integrated in the genome resulted in the production of active levansucrase. After fermentation of the recombinant yeast, LsdA activity was detected in the periplasmic fraction (81%) and in the culture supernatant (18%) with an overall yield of 1% of total protein. The recombinant LsdA was glycosylated and displayed optimal pH and temperature for enzyme activity similar to those of the native enzyme, but thermal stability was increased. Neither fructosylpolymerase activity nor FOS production was affected. Incubation of recombinant LsdA in sucrose (500 g l(-1)) yielded 43% (w/w) of total sugar as 1-kestose, with a conversion efficiency about 70%. Intact recombinant yeast cells also converted sucrose to FOS although for a 30% efficiency.
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Hernández L, Ballester E, Farré R, Badia JR, Lobelo R, Navajas D, Montserrat JM. Performance of nasal prongs in sleep studies : spectrum of flow-related events. Chest 2001; 119:442-50. [PMID: 11171721 DOI: 10.1378/chest.119.2.442] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
OBJECTIVES The use of nasal prongs connected to a pressure transducer is a noninvasive, sensitive method to detect respiratory events, and can be easily implemented in routine sleep studies. Moreover, its good time response allows the detection of several flow-related phenomena of high interest, in addition to apnea and hypopnea. The aims of the study were to examine the quality and performance of the nasal prong flow signal, and to describe other flow-related events during full-night polysomnography studies. METHODS Twenty-seven subjects were studied (16 male subjects; mean +/- SD age, 49 +/- 14 years; mean body mass index, 27 +/- 4 kg/m(2)): 15 subjects recruited from the general population and 12 consecutive patients with suspected sleep apnea/hypopnea syndrome (SAHS). RESULTS A blind analysis of the respiratory events detected both by nasal prongs and thermistor was done. The quality of the nasal prong signal recordings was considered optimal for scoring purposes in 78% of cases, and no recording was considered uninterpretable. The nasal prong signal detected additional flow-related events not observed by the thermistor: (1) short and long (> 2 min) periods of inspiratory flow limitation morphology without decrease in the amplitude of the signal; (2) periods of mouth expiration; and (3) snoring. The apnea/hypopnea index was significantly higher with the nasal prong scoring (18 vs 11 [p < 0.05] in the general population and 37 vs 27 [p < 0.001] in the group with suspected SAHS). CONCLUSIONS The incorporation of nasal prongs in routine full-night studies is an attainable technical option that provides adequate recordings in most cases. Additionally, relevant information not scored by thermistors is obtained on flow-related respiratory events, thus increasing diagnostic accuracy.
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94
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Vásquez C, Huerta M, Trujillo X, Marín JL, Hernández L. Effects of denervation on Ca2+ channels in slow skeletal muscle fibers of the frog. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2001; 126:91-9. [PMID: 11172890 DOI: 10.1016/s0165-3806(00)00143-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Effects of denervation on calcium channels in slow skeletal muscle fibers in the frog (Rana pipiens) were studied using the three-microelectrode voltage-clamp technique in intact fibers. Ca2+, Ba2+, and Sr2+ currents were all significantly reduced in amplitude during the first 2 weeks after denervation. After nerve section the selectivity sequence Ba congruent with Ca > Sr was changed to Ba > Sr > Ca and the values for relative ratio increased from 1.04 to 2.65 for Ba2+ and from 0.58 to 1.20 for Sr2+ (with respect to Ca2+). Barium current saturation was more obvious in denervated fibers than in non-denervated fibers. The values obtained with the Michaelis-Menten type expression, I = Imax/(1+Kd/[Ba]e) were Kd = 2.7 mM and Imax = 20 microA/cm2 in fibers 2 weeks after nerve section compared with the values Kd = 4.4 mM and Imax = 60 microA/cm2 obtained in non-denervated fibers. Additionally, the effects of two calcium channel blockers (cobalt and nifedipine) were greater by a factor of two in denervated fibers than in non-denervated fibers. Three weeks or so after nerve section, all the biophysical properties studied began to show a tendency to recover toward the values obtained in non-denervated muscles (controls). These results suggest that calcium channels are modified or that there is a change in the types of calcium channels present in frog slow skeletal muscle fibers after denervation.
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95
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Oliva I, González L, Esteban M, Silva I, Hernández L. Duodenotomía de descarga. Cir Esp 2001. [DOI: 10.1016/s0009-739x(01)71910-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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96
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González de la Huebra MJ, Hernández P, Ballesteros Y, Hernández L. Rapid identification of carbendazim and linuron by adsorptive stripping on a carbon fiber ultramicroelectrode. FRESENIUS' JOURNAL OF ANALYTICAL CHEMISTRY 2000; 368:853-6. [PMID: 11227576 DOI: 10.1007/s002160000561] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A method is described for the identification of a mixture of carbendazim and linuron. It is based on adsorptive stripping voltammetry at a carbon fiber ultramicroelectrode. Conditions for the determination of carbendazim in a mixture were optimized and the method was applied to soil samples. It was compared to HPLC with spectrophotometric detection, where similar results were obtained.
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97
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Pérez CJ, Alvarado P, Narváez C, Miranda F, Hernández L, Vanegas H, Hruska A, Shelton AM. Assessment of insecticide resistance in five insect pests attacking field and vegetable crops in Nicaragua. JOURNAL OF ECONOMIC ENTOMOLOGY 2000; 93:1779-1787. [PMID: 11142313 DOI: 10.1603/0022-0493-93.6.1779] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Field populations of Hypothenemus hampei (Ferrari), Plutella xylostella (L.), Spodoptera exigua (Hübner), Helicoverpa zea (Boddie) and Bemisia tabaci (Gennadius) were tested for resistance to several insecticides commonly used in Nicariagua. Assays were conducted to estimate the LD50s or LC50s and the corresponding resistance ratios. A diagnostic concentration was used to discriminate between susceptible and resistant strains of H. hampei. The tests with >6,000 H. hampei adults collected from six different sites indicate the absence of resistance to endosulfan. Resistance to cypermethrin, deltamethrin, chlorfluazuron, thiocyclam, and methamidophos was documented in six field populations of P. xylostella. High levels of resistance to cypermethrin and deltamethrin, but moderate levels of resistance to chlorpyriphos and methomyl, were also documented in two field populations of S. exigua. Moderate levels of resistance to cypermethrin, deltamethrin and chlorpyriphos were also documented in three field populations of H. zea. Moderate to high levels of resistance to bifenthrin, methamidophos and endosulfan were documented in four field populations of B. tabaci. The presence of significant correlations between LD50s or LC50s suggests the occurrence of cross-resistance or simultaneous selection for resistance by different insecticides with different modes of action. Our data could not differentiate between these two possibilities. Because insecticides will continue being used in Nicaragua, a resistance management program is urgently needed. The implementation of integrated pest management tactics must be accompanied by specific regulations for pesticide registration. In the future, pesticide registration regulations in Nicaragua should include periodic resistance monitoring. The mechanisms to cover the costs of resistance monitoring and resistance management should also be established.
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98
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Redondo J, Manso AM, Pacheco ME, Hernández L, Salaices M, Marín J. Hypothermic storage of coronary endothelial cells reduces nitric oxide synthase activity and expression. Cryobiology 2000; 41:292-300. [PMID: 11222026 DOI: 10.1006/cryo.2000.2285] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Preservation with University of Wisconsin (UW) solution has been implicated in coronary artery endothelial damage and loss of endothelium-dependent vasodilatation. Therefore, the objective of this study was to investigate the effect of this solution on basal nitric oxide (NO) release from porcine coronary endothelial cells (CEC). Cultures were exposed to cold (4 degrees C) storage in UW solution for 6, 8 and 12 h. Parallel cultures were incubated with control medium at 37 degrees C. After treatment, NO release was evaluated by nitrite production, a stable metabolite of NO. Activity of the constitutive endothelial nitric oxide synthase (eNOS) was measured by the conversion [3H]-l-arginine to [3H]-l-citrulline and eNOS protein expression by Western blotting. Nitrite production by control cells was augmented with increasing times of incubation, whereas no change was observed in those cultures preserved with UW solution. Activity of eNOS was significantly decreased compared to the respective control group by cold storage of cells for longer periods than 6 h. Such decrease was correlated with a diminished eNOS protein expression in CEC preserved with UW solution after 8- and 12-h storage. These results suggest that prolonged hypothermic storage of CEC with UW solution does not preserve basal NO release because of a certain loss of eNOS protein, which may contribute to the reported injury of heart transplants after long-term preservation.
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Pons T, Hernández L, Batista FR, Chinea G. Prediction of a common beta-propeller catalytic domain for fructosyltransferases of different origin and substrate specificity. Protein Sci 2000; 9:2285-91. [PMID: 11305239 PMCID: PMC2144480 DOI: 10.1110/ps.9.11.2285] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The three-dimensional (3D) structure of fructan biosynthetic enzymes is still unknown. Here, we have explored folding similarities between reported microbial and plant enzymes that catalyze transfructosylation reactions. A sequence-structure compatibility search using TOPITS, SDP, 3D-PSSM, and SAM-T98 programs identified a beta-propeller fold with scores above the confidence threshold that indicate a structurally conserved catalytic domain in fructosyltransferases (FTFs) of diverse origin and substrate specificity. The predicted fold appeared related to that of neuraminidase and sialidase, of glycoside hydrolase families 33 and 34, respectively. The most reliable structural model was obtained using the crystal structure of neuraminidase (Protein Data Bank file: 5nn9) as template, and it is consistent with the location of previously identified functional residues of bacterial levansucrases (Batista et al., 1999; Song & Jacques, 1999). The sequence-sequence analysis presented here reinforces the recent inclusion of fungal and plant FTFs into glycoside hydrolase family 32, and suggests a modified sequence pattern H-x (2)-[PTV]-x (4)-[LIVMA]-[NSCAYG]-[DE]-P-[NDSC][GA]3 for this family.
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100
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Pérez J, Colasante C, Tucci S, Hernández L, Rada P. Effects of feeding on extracellular levels of glutamate in the medial and lateral portion of the globus pallidus of freely moving rats. Brain Res 2000; 877:91-4. [PMID: 10980248 DOI: 10.1016/s0006-8993(00)02658-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The globus pallidus (GP) is considered to be part of the basal ganglia and previous research has determined that it might be involved in feeding behavior. For example, it has been shown that the GP becomes active during feeding and that disinhibition of this nucleus, by locally injecting a GABA antagonist, is sufficient to induce feeding in a satiated rat. However, few studies have measured extracellular levels of glutamate during free feeding in the GP of rats. For this reason brain microdialysis coupled to capillary electrophoresis with laser-induced fluorescence was used to determine FTC-glutamate levels, either in the medial or lateral portion of the GP, of freely moving rats. Retrograde labeling of the neurons projecting to the two areas was also examined in an attempt to gain some insight on the identity of the neurons that released glutamate in the GP during feeding. Extracellular levels of glutamate-FTC differentially increased in both portions of the GP during a 2-min interval of free feeding. Retrograde labeling also showed that both areas received projections from different brain areas suggesting that each of the GP portions could be involved in separate aspects of the feeding behavior.
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