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F Campos

Publications and source records attributed to F Campos.

At least 19 recordsLinked to original sources
PubMed2006

In vivo neurochemical characterization of anatoxin-a evoked dopamine release from striatum.

Anatoxin-a (AnTx) is a natural neurotoxin, which acts as a potent and stereoselective agonist at the nicotinic acetylcholine receptors. The in vivo actions of the AnTx on dopamine (DA) release are scarcely characterized. The aim of this study was to determine the neurochemical bases for AnTx-induced striatal DA release, using the brain microdialysis technique, in freely moving rats. Local application of AnTx (3.5 mM) through the microdialysis probe produced an increase in striatal DA levels (701 +/- 51% with respect to basal values). The effect of infusion of AnTx in Ca(2+)-free Ringer medium, in Na(+)-free Ringer medium and with TTX in the medium, was inhibited. Also, reserpine pre-treatment blocked the action of AnTx on striatal DA levels. To investigate the involvement of the DA transporter, the effects of AnTx were observed in the presence of nomifensine. The coadministration of AnTx and nomifensine evoked an additive effect on striatal DA levels. The latter results show that the DA release is not mediated by a decreased DA uptake. Taken as a whole, these results suggest that the effects of AnTx are predominantly mediated by an exocytotic mechanism, Ca(2+)-, Na(+)- and TTX-dependent, and not by a mechanism mediated by the DA transporter.

Animals↗
PubMed2006

In vivo effects of the anatoxin-a on striatal dopamine release.

Anatoxin-a is an important neurotoxin that acts a potent nicotinic acetylcholine receptor agonist. This characteristic makes anatoxin-a an important tool for the study of nicotinic receptors. Anatoxin-a has been used extensively in vitro experiments, however anatoxin-a has never been studied by in vivo microdialysis studies. This study test the effect of anatoxin-a on striatal in vivo dopamine release by microdialysis.The results of this work show that anatoxin-a evoked dopamine release in a concentration-dependent way. Atropine had not any effect on dopamine release evoked by 3.5 mM anatoxin-a. However, perfusion of nicotinic antagonists mecamylamine and alpha-bungarotoxin induced a total inhibition of the striatal dopamine release. Perfusion of alpha7*-receptors antagonists, metillycaconitine or alpha-bungarotoxin, partially inhibits the release of dopamine stimulated by anatoxin-a. These results show that anatoxin-a can be used as an important nicotinic agonist in the study of nicotinic receptor by in vivo microdialysis technique and also support further in vivo evidences that alpha7*nicotinic AChRs are implicated in the regulation of striatal dopamine release.

Aconitine↗
PubMed2005

Protective effects of glutathione and cysteine on the methylmercury-induced striatal dopamine release in vivo.

The possible protective effects of glutathione (GSH), cysteine (CYS) and methionine (MET) on the Methylmercury (MeHg)-induced dopamine (DA) release from rat striatum were investigated using in vivo microdialysis coupled to HPLC with electrochemical detection. Intrastriatal infusion of MeHg 400 microM increased extracellular DA levels to 1941 +/- 199% in terms of basal levels. Infusion of MeHg 400 microM in GSH 400 microM pretreated animals, only increased striatal DA levels to 465 +/- 104%, in terms of basal levels, this increase being 76% lower than induced by MeHg alone. Conversely, the infusion of MeHg 400 microM after infusion of GSH 400 microM increased DA levels to 1019 +/- 96% in terms of basal levels, this increase being 47.5% lower than that observed in MeHg non-pretreated animals. The infusion of MeHg 400 microM in CYS 400 microM -pretreated animals, increased striatal DA levels to 740 +/- 149%, in terms of basal levels, this increase being 62% lower than that induced by MeHg in non-pretreated animals. The infusion of MeHg 400 microM in MET 400 microM pretreated animals increased striatal DA levels to 2011 +/- 230% in terms of basal, an increase that was not significantly different from that produced by MeHg 400 muM alone. In summary, the administration of compounds containing free -SH groups prevented the MeHg-induced DA release from rat striatum, probably due to the binding of MeHg to -SH groups. This would result in a lower metal availability to interact with -SH membrane proteins groups, which would decrease MeHg ability to interact with DA transporter.

Animals↗
PubMed2005

Effects of manganese on extracellular levels of dopamine in rat striatum: an analysis in vivo by brain microdialysis.

The aim of this study is to determine the effects of intrastriatal administration of MnCl2, on the extracellular levels of dopamine (DA) and metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in basal conditions and stimulated by depolarization with KCl and pargyline administration. Also, we studied the effect of MnCl2 on extracellular levels of l-Dopa in the presence of aromatic amino acid decarboxylase (AADC) inhibitor 3-hydroxybencilhydracine-HCl (NSD 1015). This study concluded that MnCl2, reduced the basal and K+-stimulated DA-release in striatum, without notably affecting the DOPAC and HVA levels. Intraperitoneal injection of pargyline increased striatal DA levels, decreasing DOPAC and HVA levels. The infusion of MnCl2 removed the increase in DA levels, without affecting DOPAC and HVA levels. Perfusion of NSD 1015 increased the extracellular levels of L-DOPA in striatum, and MnCl2 increased the effect of NSD1015 on L-Dopa.

3,4-Dihydroxyphenylacetic Acid↗
PubMed2003

Mechanisms underlying domoic acid-induced dopamine release from striatum: an in vivo microdialysis study.

The brain microdialysis technique has been used to examine the in vivo effects of the neurotoxin domoic acid (an ionotropic glutamate receptor agonist) on dopamine (DA) release in the striatum of conscious and freely moving rats. Local application of domoic acid (500 microM) through the microdialysis probe produced an increase in striatal DA content (597 +/- 96% with respect to basal levels). The release of DA induced by domoic acid was not attenuated in a Ca(+2)-free medium (469 +/- 59%) or after pretreatment with 10 mg/kg reserpine (533 +/- 79%). Intrastriatal infusion of 1 microM tetrodotoxin (TTX) partially reduced the domoic acid-evoked DA release (278 +/- 34%). Moreover, domoic acid perfusion had no effect on K+-evoked DA release. The results suggest that domoic acid increases the striatal DA release according to a reserpine-independent, calcium-independent and partially TTX-insensitive mechanism, suggesting that these effects probably involve a nonexocytotic process. On the other hand, the inhibitor of DA uptake nomifensine (10 microM) reduced the domoic acid-evoked DA release (356 +/- 59%), suggesting that a carrier-dependent mechanism could be involved in the effect of domoic acid on the striatal DA levels.

Amphetamine↗
PubMed2003

Increased tumour necrosis factor alpha production in mesenteric lymph nodes of cirrhotic patients with ascites.

BACKGROUND: Cytokines produced in mesenteric lymph nodes of cirrhotic rats with bacterial translocation may participate in circulatory alterations of cirrhosis. AIM: To investigate whether cirrhotic patients present an increased local generation of cytokines in mesenteric lymph nodes. METHODS: Mesenteric lymph nodes from 26 cirrhotic and 10 control patients were assessed for tumour necrosis factor alpha (TNF) and interleukin 6 mRNA and protein expression by competitive reverse transcription-polymerase chain reaction, and by enzyme immunoassay and immunohistochemistry, respectively. RESULTS: Interleukin 6 levels were not different between cirrhotics and controls. Protein and mRNA TNF levels in mesenteric lymph nodes from cirrhotics were higher than in controls (p<0.05). Tissue expression of TNF by immunohistochemistry was more abundant in cirrhotics. Ascitic patients showed higher TNF levels (47 (34-54) pg/mg protein) than patients without ascites (18 (17-25) pg/mg protein) (p<0.001). Elevated TNF levels (>28 pg/mg protein) in cirrhotics were associated with a higher Child-Pugh score, the antecedent of ascites, a lower prothrombin rate, and higher bilirubin and blood TNF levels. The strongest association, confirmed by multivariate analysis, was with the presence of ascites (p<0.001). Bacterial infections after transplantation, mainly by enteric bacteria, were only detected in patients with high TNF levels in mesenteric lymph nodes (33% of patients; p=0.05). CONCLUSION: Patients with advanced liver cirrhosis, and especially with ascites, have increased local production of TNF in mesenteric lymph nodes that, in common with experimental cirrhosis, may also be induced by bacterial translocation.

Ascites↗
PubMed2002

Acremonium strictum pulmonary infection in a leukemic patient successfully treated with posaconazole after failure of amphotericin B.

A severely neutropenic patient with chronic lymphocytic leukemia developed a diffuse bilateral pulmonary infection while receiving a therapeutic daily dosage of intravenous amphotericin B for Candida glabrata esophagitis. Computed tomography of the chest showed numerous lung nodules, ground glass areas and a pleural effusion. Biopsy of one nodule demonstrated hyaline septate hyphae. Multiple sputum cultures grew Acremonium strictum. Increasing the dose of amphotericin B and the addition of itraconazole did not resolve the infection. Change of treatment to posaconazole given orally at 200 mg four times/d resulted in progressive improvement leading finally to cure after 24 weeks of therapy. Treatment with posaconazole was clinically and biologically well tolerated.

Acremonium↗
PubMed2002

[Importance of serum interleukin-6 as a mediator of systemic inflammation in patients with alpha-1 antitrypsin deficiency].

The objective of this study was to determine whether high concentrations of circulating interleukin-6 (IL-6) and/or the soluble receptor of IL-6 (SRIL-6) may mediate systemic inflammatory activity in patients with alpha-1 antitrypsin deficiency (AATD). To that end we assessed serum concentrations of IL-6 and SRIL-6 for 7 patients with AATD in stable phase. The patients' mean age was 51 years (SD 5.2); mean FEV1% was 35.5% (SD 15%). IL-6 and SRIL-6 concentrations were compared with those of 23 non-AATD patients with COPD but with similar changes in lung function (mean age 63 years, SD 10.1; FEV1% 38.3%, SD 11%). The AADT patients had mean IL-6 concentrations of 4.7 pg/mL (interquartile range [IR( 4.0) and RSIL-6 levels of 129.1 ng/mL (IR 31.5). The COPD patients had IL-6 concentrations of 4.1 pg/mL (IR 4.2) and SRIL-6 levels of 140.8 ng/mL (IR 71). No significant differences between the AADT group and the COPD group were observed for either cytokine (non-parametric Mann Whitney U test, p > 0.05). Only one AADT patient had an IL-6 concentration that was higher than normal. In conclusion, the serum IL-6 and SRIL-6 concentrations of patients with AADT are not different from those of patients with COPD, similarly altered respiratory function and normal alpha-1 antitrypsin levels. These results do not point to a role for alpha-1 antitrypsin in systemic inflammatory stimulation in patients with AADT.

Data Interpretation, Statistical↗
PubMed2001

[Prevalence of hypovitaminosis D in elderly institutionalized residents: influence of a substitutive treatment].

BACKGROUND: Osteoporosis in the elderly is a common and severe disease, vitamin D deficiency being an important causative factor. Hypovitaminosis D is frequent in old people, particularly those living in nursing homes. SUBJECTS AND METHOD: We performed a cross-sectional study of 100 randomly recruited elderly institutionalized subjects. The prevalence of hypovitaminosis D and its possible repercussion on the phosphocalcium metabolism were assessed. The degree of sun exposure and the existence of co-morbidity were also recorded. Individuals with hypovitaminosis D were included in a longitudinal study (6 months' duration) aimed at assess the efficacy of treatment with calcium and two different therapeutic regimens with calcidiol (16,000 IU/week or 16,000 IU every 3 weeks). RESULTS: 87% of individuals had hypovitaminosis D; 21.8% of them had secondary hyperparathyroidism. The study population had a low degree of sun exposure and a high level of co-morbidity. The two doses of calcidiol led to a normalization of 25-OHD3 levels, increased calciuria and compensated secondary hyperparathyroidism, yet higher 25-OHD3 levels were achieved with the weekly therapeutic scheme. CONCLUSIONS: Hypovitaminosis D prevalence appears to be very high In the elderly institutionalized population. Calcium and calcidiol supplementation normalized 25-OHD3, improved calcium absorption and compensated secondary hyperparathyroidism. Calcium and vitamin D supplementation should be employed routinely in the elderly institutionalized population.

Aged↗
PubMed2001

Primary aortoenteric fistula related to septic aortitis.

CONTEXT: Primary aortoenteric fistulas usually result from erosion of the bowel wall due to an associated abdominal aortic aneurysm. A few patients have been described with other etiologies such as pseudoaneurysm originating from septic aortitis caused by Salmonella. OBJECTIVE: To present a rare clinical case of pseudoaneurysm caused by septic aortitis that evolved into an aortoenteric fistula. CASE REPORT: A 65-year-old woman was admitted with Salmonella bacteremia that evolved to septic aortitis. An aortic pseudoaneurysm secondary to the aortitis had eroded the transition between duodenum and jejunum, and an aortoenteric fistula was formed. In the operating room, the affected aorta and intestinal area were excised and an intestine-to-intestine anastomosis was performed. The aorta was sutured and an axillofemoral bypass was carried out. In the intensive care unit, the patient had a cardiac arrest that evolved to death.

Aged↗
PubMed2001

A cDNA for nuclear-encoded chloroplast translational initiation factor 2 from a higher plant is able to complement an infB Escherichia coli null mutant.

Formation of the initiation translation complex containing the three initiation factors, IF1, IF2, and IF3, tRNA(fMet), and GTP constitutes the earliest event in the protein synthesis. IF2, a GTP-binding protein, is the principal factor involved in selecting and binding fMet-tRNA(fMet) to the 30 S ribosomal subunit. Although some chloroplast initiation translational factors have been identified and purified from algae, none of these factors have been characterized from plants. In this work, we report the molecular characterization of a nuclear-encoded chloroplastic IF2 gene from common bean (PvIF2cp). We show that the PvIF2cp gene encodes a protein containing a chloroplast translocation signal peptide, able to target a green fluorescent protein fusion protein to chloroplasts. A high accumulation of PvIF2cp transcript was found in photosynthetic tissues, whereas low mRNA levels were detected in etiolated plants and in nonphotosynthetic organs. Additional data indicate that the PvIF2cp transcript accumulation is modulated by light. The PvIF2cp gene encodes a functional factor, since the PvIF2cp conserved region, containing the G-domain and the C-terminal end, complements an Escherichia coli infB null mutation. Phylogenetic analysis using the PvIF2cp conserved region suggests that the PvIF2cp gene originated via endosymbiotic gene transfer to the nucleus and that it may be a useful marker for phylogeny reconstruction.

Active Transport, Cell Nucleus↗
PubMed2001

[Isolated neurologic disorders disclosing Biermer's disease in young subjects].

INTRODUCTION: In young subjects, the discovery of a cobalamine deficiency (Biermer's disease) at the time of neuropsychiatric disorders even of isolated MRI anomalies is a rare event (less than 0.01%). EXEGESIS: We report two observations of cobalamine deficiency, in patients 30 and 37 years old, revealed by acroparesthesia and spontaneous hypersignal in the T2 sequence of MRI and by a peripheral sensitive neuropathy respectively. CONCLUSION: The neuropsychiatric demonstrations of pernicious anemia are polymorphic with, sometimes, isolated spinothalamic attacks. The MRI can contribute to the diagnosis but more often leads to an erroneous diagnosis. Our observations are of special interest because symptoms occurred apart from supplementation of folates and recovered ad integrum with an early treatment by vitamin B12.

Adult↗
PubMed2001

Rifampin reduces concentrations of trimethoprim and sulfamethoxazole in serum in human immunodeficiency virus-infected patients.

To determine whether rifampin reduces concentrations of trimethoprim (TMP) and sulfamethoxazole (SMX) in serum of human immunodeficiency virus (HIV)-infected persons, levels of these agents were determined by high-performance liquid chromatography before and after more than 12 days of standard antituberculosis treatment for 10 patients who had been taking one double-strength tablet of co-trimoxazole once daily for more than 1 month. Statistically significant, 47 and 23% decreases in TMP and SMX mean areas under the concentration-time curve from 0 to 24 h (AUC(0-24)), respectively, were observed after administration of rifampin. N-Acetyl-SMX profiles without and with rifampin were similar. The steady-state AUC(0-24) metabolite/parent drug ratio increased by 32% with rifampin administration. Our study shows that rifampin reduces profiles of TMP and SMX in serum of HIV-infected patients.

Adult↗
PubMed2000

[Is there a place for interferon-alpha in the treatment strategy of multicentric Castleman's disease?].

INTRODUCTION: Castleman's disease is an unusual condition of unknown cause, consisting of massive proliferation of lymphoid tissue. Two forms (localized and multicentric) have been described. Interleukin-6 (IL-6) is at the core of the disease, being responsible for most of the clinical and biological signs that may be observed. Despite the benignancy of this pre-lymphoma condition, its course is usually aggressive and of poor prognosis in regard to the multicentric form. No consensus regarding treatment has been defined. Available data on the multicentric form of the disease are to scarce to allow any conclusion about the treatment timing and type of chemotherapy best suited to this condition. We report the case of a patient in whom interferon alpha (IFN-alpha) was used as first line treatment. EXEGESIS: The case of a 52-year-old man with multicentric Castleman's disease combined with high IL-6, in whom, however, testing for human herpes virus-8 proved to be negative, is described. Interferon alpha (4.5 MU/m2 three times per week during 18 months) administered as first line treatment induced dramatic improvement in the patient's general condition and normalization of the tumoral syndrome. Moreover, biological parameters and IL-6 returned to normal. Two years after interferon disruption, complete remission is still present. CONCLUSION: On the basis of the present data and those of two previous observations, anti-IL-6 and anti-infective properties of IFN-alpha are discussed. Treatment of multicentric Castleman's disease is based on corticosteroids and drugs derived from those pertaining to treatment of malignant lymphomas. Our results indicate that IFN-alpha is truly directed against Castleman's disease and has less toxicity than drugs usually prescribed. This argues for early use of IFN-alpha in Castleman's disease, in association or not with corticosteroids.

Castleman Disease↗
PubMed2000

Two bean cell wall proteins more abundant during water deficit are high in proline and interact with a plasma membrane protein.

Two antigenically related glycoproteins, called p33 and p36, accumulate in the soluble fraction of the cell wall in response to water deficit in Phaseolus vulgaris. In this report, we show that p33 and p36 are able to adhere to leaf protoplasts, and that they bind to plasma membrane (PM) vesicles in a divalent cation-dependent manner. Data from the partial amino acid sequence of the p33 and p36 proteins indicate that they contain repeats of the decapeptide POVYKPOVEK; therefore, they are related to proline-rich proteins. Binding assays demonstrate that both proteins specifically bind to an 80 kDa PM protein. This binding is competed with a peptide that contains the RGD motif, as well as with fibronectin, which also includes this sequence, suggesting that the 80 kDa PM protein has an integrin-like function whose natural ligands are p33 and p36. This is the first case where a PM ligand for a higher plant cell wall protein has been identified.

Amino Acid Sequence↗
PubMed2000

Genomic and antigenic variation among rotavirus strains circulating in a large city of Argentina.

Knowledge of the antigenic diversity of rotaviruses circulating in a region should be acquired before introducing a rotavirus vaccine. In a collection of 151 rotavirus-positive samples from Mendoza, Argentina, strain diversity was evaluated utilizing G-typing monoclonal antibodies (MAbs), reverse-transcriptase-polymerase chain reaction (RT-PCR) G and P typing, and electropherotyping (PAGE). The G type of 137 (91%) specimens was determined. Typing MAb reactivity with the homologous type ranged from 25-94%. For the seven G1 MAbs utilized, 28 patterns of reactivity among 68 G1 strains occurred. For the 48 G2 strains, six patterns of reactivity occurred utilizing three G2-specific MAbs. Of the 92 samples G- and P-typed by reverse-transcriptase-polymerase chain reaction, 89% had single G/P combinations: eight G1[P4], one G1[P6], twelve G1[P8], 58 G2 [P4], and two G2 [P6]. Nine samples had more than one G type with a single P type, one sample had two P types associated with one G type, and one sample contained multiple G and P types. Twenty-nine PAGE patterns occurred for all G types, but differences of antigenic reaction did not predict differences in migration of gene segments 7, 8, and 9. For three specimens showing discordant results between G type by enzyme-linked immunosorbent assay (EIA) and RT-PCR, we observed unexpected electropherotypes. Complementary evaluation by RT-PCR and MAb-based EIA with multiple typing MAbs revealed genetic and antigenic diversity of circulating rotaviruses, including extensive intratypic variation of the G1 and G2 neutralization antigens, in Mendoza during a single season of rotavirus activity.

Antibodies, Monoclonal↗