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Biomedical subjects

A Arranz

Publications and source records attributed to A Arranz.

At least 19 recordsLinked to original sources
PubMed2006

VIP-PACAP system in immunity: new insights for multitarget therapy.

Our research about VIP/PACAP and the immune system goes back to 1990 when our group described the expression of VIP on lymphocytes for the first time. Since this year, using three models of disease, septic shock, rheumathoid arthritis, and Crohn's disease, we are trying to contribute with new pieces to the puzzle of immunity to approach the use of VIP/PACAP system as a therapeutic agent. In 1999 we established that the first step in the beneficial effect of the VIP/PACAP system exerts consists in its potent anti-inflammatory action. Thus, VIP and PACAP inhibit the expression and release of proinflammatory cytokines and chemokines, and enhance the production of the anti-inflammatory factors. These effects were reported both in vitro and in vivo, are mediated by the presence of PAC1, VPAC1, and VPAC2 receptors, in the three models of diseases used. The next step was that the system favors Th2 responses versus Th1 contributing to the remission of illness as rheumatoid arthritis or Crohn's disease by blocking the autoimmune component of these diseases. Because it appears that inflammatory processes requires more than blockade of a single mediator, new therapies blocking several components of both the infection- and the autoimmunity-induced inflammation cascades should be an interesting focus of attention. In this sense, at present we are trying to dissect new aspects of the potential therapeutic of the VIP/PACAP system in the control of CC and CXC chemokine and their receptors, coagulation factors, adhesion molecules, acute phase proteins, and osteoclastogenesis mediators as well as in the modulation of the expression of Toll-like receptors. Our more recent data open a hopeful door for the therapeutic use of VIP/PACAP in humans.

Animals↗
PubMed2006

VIP decreases TLR4 expression induced by LPS and TNF-alpha treatment in human synovial fibroblasts.

It has been demonstrated that VIP produces beneficial effects both in a murine model of rheumatoid arthritis and in human rheumatoid synovial fibroblasts through the modulation of proinflammatory mediators. Toll-like receptors (TLRs) play a key role in the immediate recognition of microbial surface components by immune cells prior to the development of adaptative microbe-specific immune responses. In this study, we demonstrate that VIP decreases lipopolysaccharide (LPS) and TNF-alpha-induced expression of TLR4 and its correlation with the production of CCL2 and CXCL8 chemokines in human synovial fibroblasts from patients with rheumatoid arthritis and osteoarthritis. Our results add a new step for the use of VIP, as a promising candidate, for the treatment of rheumatoid arthritis.

Cells, Cultured↗
PubMed2005

VIP down-regulates TLR4 expression and TLR4-mediated chemokine production in human rheumatoid synovial fibroblasts.

OBJECTIVES: Vasoactive intestinal peptide (VIP) has demonstrated therapeutic effects in arthritis by inhibiting both innate and acquired immune responses. We investigated the potential effects of VIP in the regulation of Toll-like receptor (TLR) expression and function in synovial fibroblasts from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). METHODS: Cultured fibroblast-like synoviocytes (FLS) were obtained from patients with RA and OA. The effects of VIP on basal or TNF-alpha or lipopolysaccharide (LPS)-induced TLR2, TLR4 and MyD88 expression and its effects on TLR4-mediated CCL2 and CXCL8 chemokine production were studied by reverse transcription-polymerase chain reaction, western blotting and enzyme-linked immunosorbent assay. RESULTS: TLR2, TLR4 and MyD88 mRNA expression was increased in RA FLS compared with OA FLS. The largest increase was observed for TLR4 and there was also overexpression at the protein level in RA FLS. TLR4 and MyD88 mRNA and proteins were induced by LPS and TNF-alpha in RA FLS. VIP down-regulated the induced but not the constitutive expression of TLR4 and MyD88 in RA FLS. VIP treatment decreased CCL2 and CXCL8 chemokine production in response to TLR4 activation with LPS in RA FLS. CONCLUSIONS: We demonstrate that VIP down-regulates LPS and TNF-alpha activation of TLR4 expression and the TLR4 functional response in terms of proinflammatory chemokine production. These studies suggest that the pleiotropic anti-inflammatory actions of VIP involve inhibitory effects on TLR4 expression and signalling.

Adaptor Proteins, Signal Transducing↗
PubMed2005

Epitaxy and magnetic properties of surfactant-mediated growth of bcc cobalt.

High resolution core level photoemission spectroscopy, photoelectron diffraction, and x-ray magnetic circular dicroism (XMCD) have been used to characterize the structural and magnetic properties of bcc-cobalt films grown on GaAs(110) substrates by using Sb as a surfactant. We have unambiguously disentangled the surfactant role played by the Sb which improves the crystallinity and reduces the lattice distortion of the metallic films as well as changes the interdiffusion process at the interface compared to the Co/GaAs(110) system. As a consequence of these combined effects, an improvement on the magnetic response of the grown Co thin films has been observed by XMCD measurements.

Journal Article↗
PubMed2001

Vasoactive intestinal peptide in the immune system: potential therapeutic role in inflammatory and autoimmune diseases.

Vasoactive intestinal peptide (VIP), a neuropeptide that is produced by lymphoid as well as neural cells, exerts a wide spectrum of immunological functions, controlling the homeostasis of the immune system through different receptors expressed in various immunocompetent cells. In the last decade, VIP has been clearly identified as a potent anti-inflammatory factor, which acts by regulating the production of both anti- and pro-inflammatory mediators. In this sense, VIP has been described to prevent death by septic shock, an acute inflammatory disease with a high mortality. In addition, VIP regulates the expression of co-stimulatory molecules, this being an action that may be related to modulating the shift toward Th1 and Th2 differentiation. We have recently reported that VIP prevents the deleterious effects of an experimental model of rheumatoid arthritis, by downregulating both inflammatory and autoimmune components of the disease. Therefore, VIP has been proposed as a promising candidate alternative treatment for acute and chronic inflammatory and autoimmune diseases such as septic shock, arthritis, multiple sclerosis, Crohn disease, or autoimmune diabetes.

Animals↗
PubMed2000

Capillary zone electrophoretic separation and determination of imidazolic antifungal drugs.

Capillary zone electrophoresis (CZE) was adapted to the simultaneous determination of a mixture of three imidazolic antifungal drugs. Separation was achieved by using a fused-silica capillary column with an acetic acid-Tris buffer at pH 5.18 and UV detection at 196 nm. Several electrophoretic parameters were investigated: pH and buffer concentration, applied voltage, temperature and injection conditions. The optimized CZE method was applied to the individual determination of ketoconazole, clotrimazole and econazole in pharmaceutical forms, after a previous single extraction step in methanol, with recoveries of 98.00, 99.96 and 99.58% respectively. The antifungal drugs can be determined at a concentration level lower than 1.0 x 10(-7) M.

Antifungal Agents↗
PubMed2000

[Parathyroid cysts. Their differential diagnosis from thyroid pathology. A report of 2 cases].

Parathyroid cysts are rare in clinical practice, but, when they appear, they can be mistaken for more common thyroid conditions, that can incidentally be associated with them. We present two cases of parathyroid cysts. One of them was misdiagnosed of thyroid nodule and the other was found in the context of a normo-functioning multinodular goitre. In this last case, the presenting symptoms had raised the suspicion of malignancy. Both of them responded favorably to evacuation of the liquid by means of a puncture-aspiration with a fine needle (PAFN). Our clinical cases show that the diagnosis of parathyroid cyst should be considered in patients with a cervical mass, even if an evident thyroid condition is present. They may be accurately diagnosed by means of PAFN and determining PTH in the cystic liquid, whose characteristics help to predict its side of origin.

Cysts↗
PubMed1999

Voltammetric and spectrophotometric techniques for the determination of the antihypertensive drug Prazosin in urine and formulations.

A sensitive method was developed to determine Prazosin using a nafion modified carbon paste electrode (NMCPE). Prazosin was accumulated at a potential of 750 mV in Britton-Robinson buffer (pH 6.0) and then a negative sweep was made obtaining a cathodic peak close to 0 V. Cyclic voltammetric studies indicated that the process was quasi-reversible, and fundamentally controlled by adsorption. To obtain a good sensitivity, the instrumental and accumulation variables were studied using differential pulse voltammetry (DPV). Adsorptive voltammetric peak currents showed a linear response for Prazosin concentrations in the range between 4.0 x 10(-11) and 4.0 x 10(-8) M with two different slopes, and a detection limit (LOD) of 3.1 x 10(-11)M was obtained. The variation coefficient (CV) for a 8.0 x 10(-10) M solution (n = 10) was 4.08%. A spectrophotometric study of Prazosin was also carried out and two absorption bands were obtained at 246 and 329 nm (pH 1.8). The band at 329 nm was pH-dependent and its height and position changed with the pH values, so this allowed the pK'a determination (7.14 +/- 0.20) using different methods. The detection limit reached by means of UV-spectrophotometry was 0.9 x 10(-7) M, and the variation coefficient for 1.5 x 10(-5) M Prazosin solutions was 1.14% (n = 10). Although the sensitivity of the UV-spectrophotometric method was lower than that obtained using adsorptive stripping-differential pulse voltammetry (AdS-DPV), it could be applied to the determination of Prazosin in Minipres tablets. The voltammetric method was used for the determination of the drug in human urine samples at trace levels with good recoveries.

Antihypertensive Agents↗
PubMed1998

Mild or absent clinical signs in twin sisters with short-chain acyl-CoA dehydrogenase deficiency.

UNLABELLED: Two HLA-identical twin sisters are reported, of whom one has remained essentially asymptomatic, and an episode of hypotonia and decreased level of conciousness being the only relevant clinical finding in the other. Organic acid-analysis revealed that ethylmalonate was constantly, although sometimes only slightly, increased. No abnormal acylglycines or acylcarnitines could be detected. Enzyme assay in cultured skin fibroblasts confirmed short-chain acyl-CoA dehydrogenase deficiency. CONCLUSION: The lack of appropriate biochemical markers for this deficiency makes the diagnosis difficult and consequently, the low number of patients described may be the result of underdiagnosis.

Acyl-CoA Dehydrogenase↗
PubMed1998

[Epidemic outbreak of Salmonella richmond infection in Castellón, Spain].

A case-control study was carried out to investigate an outbreak of acute gastroenteritis among a military detachment stationed in a rural area of Castellón, España. The purpose of the study was to determine the causes of the outbreak and develop control measures. Of the 153 men in the detachment, 135 were included in the study. Between 9 and 11 August 1993, 45 cases were reported; the patients' average age was 19.2 +/- 1.5 years. The attack rate was 33.3%. The clinical picture was dominated by the following symptoms: diarrhea (76%), vomiting (67%), nausea (67%), and abdominal pain (28%). The median duration of symptoms was one day, and that of the incubation period was 33 hours. Only one patient required hospitalization and all of them recovered. Salmonella richmond (6.7: and :1.2) was isolated in 5 of the 14 stool cultures performed. An association was also discovered between the illness and consumption of water from an aqueduct that flowed near the camp. A logistic regression model showed that consumption of water from this source remained associated with cases after adjusting for age and the consumption of various foods (odds ratio = 96.5; 95% confidence interval, 11.4-814.4). The risk of suffering from the illness rose with the amount of water consumed (chi 2 trend test = 65.4, P < 0.0001). Chemical and bacteriological analyses of the aqueduct water indicated the presence of fecal contamination. The aqueduct had not been subject to sanitary monitoring, even though the water was used to irrigate agricultural crops. The widespread presence in the environment of species of Salmonella was demonstrated. Health education and microbiological studies of water courses can be of great value in preventing such epidemics.

Adult↗
PubMed1997

Cathodic stripping voltammetric determination of doxazosin in urine and pharmaceutical tablets using carbon paste electrodes.

Several voltammetric techniques were used to explore the reductive behaviour of the antihypertensive agent doxazosin on a bare carbon paste (CPE) and a Tenax-modified carbon paste electrode (TMCPE). The results indicate that the process is irreversible and fundamentally controlled by adsorption, which allows doxazosin to be accumulated at the electrode surface. The cathodic adsorptive stripping (AdS) response was evaluated with respect to pH, accumulation variables and instrumental parameters, using differential-pulse (DPV) and square-wave voltammetry (SWV) as redissolution techniques. In both cases, a voltammetric peak close to 0 V in Britton-Robinson buffer (pH 6.6) was obtained after a preconcentration step at 0.55 V for 3 min (2000 rpm) and a subsequent cathodic scan. When the TMCPE was used, the limits of detection were 4.35 x 10(-11) and 5.18 x 10(-11) M for AdS-DPV and AdS-SWV, respectively. The deposition time (3 min) was improved relative to that obtained by means of CPE (6 min). Under the optimum operational conditions, the doxazosin reduction peak showed a linear response in the range from 6 x 10(-11) to 1 x 10(-9) M by using AdS-DPV, with an RSD of 3.39% for 3 x 10(-8) M doxazosin solution (n = 10). A method was developed for the determination of doxazosin in human urine and formulations.

Adsorption↗
PubMed1996

Thyroid autoimmune disorders in patients with chronic hepatitis C before and during interferon-alpha therapy.

BACKGROUND AND AIMS: Hepatitis C virus is involved in the induction of autoimmunity and interferon can also induce hepatic and non-hepatic autoimmune reactions. This study assessed the prevalence of thyroid autoantibodies and autoimmune thyroid disorders in patients with chronic hepatitis C before and during interferon therapy. PATIENTS AND METHODS: We studied prospectively 207 patients positive for anti-HCV and viral RNA. One hundred and forty-four of them received a therapeutic trial of one year with interferon-alpha. Free thyroxine, TSH and autoantibodies to thyroglobulin and thyroid microsomes were systematically tested at entry and at weeks 12 and 24 in both untreated and treated patients. RESULTS: Sixteen of the 207 patients (7.7%) had thyroid dysfunction, including positive antithyroid antibodies in 14 (6.7%) and hypothyroidism in 10 (4.8%) prior to interferon therapy. In addition, during pretreatment evaluation one patient developed clinical hyperthyroidism after transient subclinical hypothyroidism and another had subclinical hyperthyroidism. Prevalences of positive antithyroid antibodies and hypothyroidism were significantly higher in women (14.7 and 10.5%, respectively, vs 0% in men, P < 0.01) and were directly associated with increasing age (P < 0.01). The incidence of thyroid dysfunction was also significantly higher in patients with other autoantibodies such as anti-nuclear (ANA) (P < 0.01). A trial with interferon was initiated in 144 patients and 8 of 142 (5.6%) without previous thyroid abnormalities developed thyroid dysfunction, including positive antithyroid antibodies in 7 (4.9%) and hypothyroidism in 4 (2.8%) with a prevalence again significantly higher in women (12.7 and 8.3%, respectively, vs 1% in men, P < 0.01) and also directly related to increasing age (P < 0.01). An association was found between the development of thyroid dysfunction during interferon therapy and the presence of other autoantibodies, including ANA, anti-DNA and anti-Sjögren's antibodies (P < 0.01), as well as with the induction of autoimmune hepatitis and Sjögren's syndrome (P < 0.01 and < 0.05 respectively). Thyroid abnormalities were reversed in all patients when interferon therapy was discontinued. CONCLUSIONS: No significant association was found between chronic hepatitis C and the presence of thyroid autoimmunity in female patients. On the contrary, interferon therapy induced antithyroid autoantibodies and thyroid dysfunction de novo in patients with chronic hepatitis C without pre-existing thyroid abnormalities. Thyroid dysfunction secondary to interferon was reversible after discontinuation of therapy.

Adult↗
PubMed1993

Disappearance of serum hepatitis B virus DNA by polymerase chain reaction after adenine arabinoside 5'-monophosphate therapy in chronic hepatitis B.

The aim of antiviral therapy in chronic hepatitis B is the cessation of viral replication, which may be demonstrated by the loss of hepatitis B "e" antigen (HBeAg) and serum hepatitis B virus DNA (HBV-DNA) detected by dot-blot hybridization. With the development of the sensitive polymerase chain reaction (PCR) technique for detecting HBV-DNA, it has become apparent that many HBeAg negative patients may still have small amounts of circulating viral DNA. We assessed 19 of 25 patients with chronic hepatitis B who seroconverted from HBeAg to anti-HBe after adenine arabinoside 5'-monophosphate therapy (5 mg.kg-1.day-1 for 7 weeks) to determine whether serum HBV-DNA became undetectable. Sixteen of the 19 HBeAg negative patients remained hepatitis B surface antigen (HBsAg) positive, and the other three lost HBsAg during follow-up. All of them were HBV-DNA negative by dot-blot hybridization. Using the PCR technique, HBV-DNA became negative in 13 (81.2%) of the 16 patients who seroconverted to anti-HBe without losing HBsAg, and in all the patients who lost HBsAg. These data suggest that the majority of patients who respond to adenine arabinoside 5'-monophosphate show a complete inhibition of hepatitis B virus replication, as demonstrated by the absence of viral DNA by PCR. This inhibition was present in all patients who, at the same time, lost HBsAg.

Adult↗
PubMed1992

Use of derivatization reactions with adsorptive stripping voltammetry for determining fotemustine in biological samples.

A method is described for determining the new fotemustine antineoplastic in human serum. The method is based on the derivatization of the original molecule by means of diazotization and coupling reactions. The derivatization product is determined by means of adsorptive stripping voltammetry. The calibration graphs were linear over the range 6 x 10(-9)-8 x 10(-7) and 6 x 10(-10)-8 x 10(-8) M, according to whether the coupling reagent was 1-naphthylamine or 1-naphthol, respectively. At the same time, the detection limits are 4.1 x 10(-9) and 1.4 x 10(-10) M, respectively. The method was applied to determine this antineoplastic in human serum, after a liquid-liquid extraction process, from which recovery factors of 95.6% has been obtained.

Antineoplastic Agents↗