PubMed Health⌕ Search

Biomedical subjects

E Calvo

Publications and source records attributed to E Calvo.

At least 37 records · Page 2Linked to original sources
PubMed2004

Sequential changes of parathyroid hormone related protein (PTHrP) in articular cartilage during progression of inflammatory and degenerative arthritis.

OBJECTIVE: To investigate immunolocalisation of parathyroid hormone related protein (PTHrP) in two sequential models of experimental cartilage damage (inflammatory and degenerative) in order to elucidate differences in chondrocyte response to the disease. METHODS: Immunohistochemistry with a polyclonal rabbit antiserum to the N-terminal domain of PTHrP was used to detect this protein in two different rabbit models sharing progressive cartilage damage: antigen induced arthritis (AIA) and osteoarthritis (OA) secondary to partial medial meniscectomy. Cartilage specimens from early (2 days in AIA; 8 weeks in experimental OA) and late (3 weeks in AIA; 52 weeks in OA) disease were compared. RESULTS: Cell and matrix PTHrP staining in early AIA and OA was similar to that in controls. Late AIA cartilage showed a significant decrease in PTHrP positive cells and in the cartilage matrix. In contrast, at late OA stages, distinct PTHrP positivity was detected in proliferating cell clones, as assessed by proliferating cell nuclear antigen staining around cartilage damaged areas. CONCLUSION: PTHrP staining of hyaline articular cartilage shows a different pattern during progression of each type of arthritis: an overall decrease associated with the inflammatory disease, and an increase in the proliferating chondrocyte clones with degenerative arthritis.

Animals↗
PubMed2003

Vertebroplasty in the treatment of vertebral tumors: postprocedural outcome and quality of life.

The results of percutaneous vertebroplasty with polymethylmethacrylate (PMMA) of vertebral metastases were evaluated by a retrospective review of a consecutive series of 21 patients, with special reference to functional outcome. Patients complained of vertebral pain in all cases. Walking was impossible for 13 patients. Ten patients presented neurological deficit. Treatment included percutaneous vertebroplasty in all patients, radiotherapy in 15 patients and neural decompression surgery in 3 patients. Mean duration of hospitalization was 14.1 days (range 2-60 days) and the mean follow-up was 5.6 months (range 1-18 months). Preprocedural pain, measured by the visual analog scale (VAS), was 9.1, decreasing to 3.2 after the procedure and 2.8 at the last follow-up visit. Morphinics were discontinued in 7 of 14 patients following discharge from hospital. Ten out of 13 (77%) patients recovered walking capacity. Neurological status improved in three out of five patients. No further vertebral compression occurred in the vertebrae treated. Overall, 81% of the patients in this study were satisfied or very satisfied with the procedure. One patient (5%) had transitory radicular neuritis after the procedure. No major complications were observed. In conclusion, percutaneous vertebroplasty with PMMA proved to be safe and beneficial, providing significant and early improvement in the functional status of patients with spinal metastasis.

Back Pain↗
PubMed2003

The Musca domestica larval hexamerin is composed of multiple, similar polypeptides.

The Musca domestica larval hexamerin (MdHex-L) is a hexameric glycoprotein with an apparent native molecular weight of 500 kDa. Seven different cDNAs that encode MdHex-L subunits were cloned and sequenced. Furthermore, amino acid sequences of isolated subunits were determined by the Edman degradation method and compared to the conceptual translation products derived from the cloned cDNAs. The obtained data indicate the existence of multiple forms of MdHex-L subunits and that these multiple forms may be grouped into three categories according to their percentages of nucleotide sequence identity.

Amino Acid Sequence↗
PubMed2003

Glucosamine inhibits IL-1beta-induced NFkappaB activation in human osteoarthritic chondrocytes.

OBJECTIVE: Glucosamine sulfate (GS) is a commonly used drug for the treatment of osteoarthritis. The mechanism of the action of this drug does, however, remain to be elucidated. In human osteoarthritic chondrocytes (HOC) stimulated with a proinflammatory cytokine, we studied whether GS could modify the NFkappaB activity and the expression of COX-2, a NFkappaB-dependent gene. METHODS: Using HOC in culture stimulated with interleukin-1 beta (IL-1beta), the effects of GS on NFkappaB activation, nuclear translocation of NFkappaB/Rel family members, COX-1 and COX-2 expressions and syntheses and prostaglandin E2 (PGE2) concentration were studied. RESULTS: GS significantly inhibited NFkappaB activity in a dose-dependent manner, as well as the nuclear translocation of p50 and p65 proteins. Furthermore, GS-preincubated IL-1beta-stimulated HOC showed an increase in IkappaBalpha in the cell cytoplasm in comparison with HOC incubated with IL-1beta alone. GS also inhibited the gene expression and the protein synthesis of COX-2 induced by IL-1beta, while no effect on COX-1 synthesis was seen. GS also inhibited the release of PGE2 to conditioned media of HOC stimulated with IL-1beta. CONCLUSIONS: GS inhibits the synthesis of proinflammatory mediators in HOC stimulated with IL-1beta through a NFkappaB-dependent mechanism. Our study further supports the role of GS as a symptom- and structure-modifying drug in the treatment of OA.

Acetylglucosamine↗
PubMed2003

Analysis of the wild-type and mutant genes encoding the enzyme kynurenine monooxygenase of the yellow fever mosquito, Aedes aegypti.

Kynurenine 3-monooxygenase (KMO) catalyses the hydroxylation of kynurenine to 3-hydroxykynurenine. KMO has a key role in tryptophan catabolism and synthesis of ommochrome pigments in mosquitoes. The gene encoding this enzyme in the yellow fever mosquito, Aedes aegypti, is called kynurenine hydroxylase (kh) and a mutant allele that produces white eyes has been designated khw. A number of cDNA clones representative of wild-type and mutant genes were isolated. Sequence analyses of the wild-type and mutant cDNAs revealed a deletion of 162 nucleotides in the mutant gene near the 3'-end of the deduced coding region. RT-PCR analyses confirm the transcription of a truncated mRNA in the mutant strain. The in-frame deletion results in a loss of 54 amino acids, which disrupts a major alpha-helix and which probably accounts for the loss of activity of the enzyme. Recombinant Ae. aegypti KMO showed high substrate specificity for kynurenine with optimum activity at 40 degrees C and pH = 7.5. Kinetic parameters and inhibition of KMO activity by Cl- and pyridoxal-5-phosphate were determined.

Aedes↗
PubMed2003

Fibrin generated in the synovial fluid activates intimal cells from their apical surface: a sequential morphological study in antigen-induced arthritis.

OBJECTIVE: Fibrin deposits adhered to the synovial surface are typical of rheumatoid joints. Since fibrin appears to have a role in arthritis perpetuation our aim was to investigate how these deposits are formed and the consequences of their adhesion to the tissue. METHODS: The appearance of fibrin aggregates either free in the synovial fluid or attached to the membrane was studied in rabbits with antigen-induced arthritis by histological techniques at different time points from challenge. In the fixed synovial membranes areas of fibrin-bound synovium were evaluated by qualitative variables to obtain a sequential profile of morphological changes. RESULTS: Fibrin aggregates appeared from the initial stages of the disease in the synovial effusion. Later on, they were localized on the synovial surface and progressive changes were noted at the fibrin-tissue interface, ending with the invasion of the aggregates by synovial cells and their incorporation into the tissue. CONCLUSION: Fibrin aggregates generated inside the joint cavity may constitute a source of activation and acquisition of invasiveness of the synovial fibroblasts, a process to explore within the perpetuating mechanisms of rheumatoid arthritis.

Animals↗
PubMed2003

A fibrin based model for rheumatoid synovitis.

Intracavitary fibrin clots may initiate pannus formation and the immunopathology of RA. Two critical steps, probably host dependent, may determine the development of RA: an altered regulation of extravascular haemostasis or an aberrant reactivity of synovial fibroblasts to the adhered fibrin clots. Current treatments for RA target events downstream of fibrin deposition, perhaps agents acting at an earlier stage should be tried.

Arthritis, Rheumatoid↗
PubMed2003

Two digestive trypsins occur in three species of neotropical anophelines.

Trypsin activity increases in the midgut of Anopheles aquasalis, Anopheles albitarsis, and Anopheles darlingi after a bloodmeal. The activity returns to basal levels at the time the blood is completely digested. Affinity chromatography, reversed-phase high performance liquid chromatography (HPLC), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used to sequentially purify the mosquito trypsins found in the midguts at 24 h after feeding. Aminoterminal sequencing of the purified trypsins showed the occurrence of two distinct trypsins in the midgut of each of the mosquitoes studied. The sequences obtained are similar to those of the trypsins of other hematophagous insects.

Amino Acid Sequence↗
PubMed2002

Comparison of unidimensional and bidimensional measurements in metastatic non-small cell lung cancer.

Tumour response evaluation after chemotherapy has become crucial in the development of many drugs. In contrast to the standard bidimensional WHO criteria, the recently described Response Evaluation Criteria In Solid Tumors are based on unidimensional measurements. The aim of the present study was to compare both methods in patients with metastatic non-small cell lung cancer. One hundred and sixty-four patients treated with two cisplatin-paclitaxel-based chemotherapy schedules between June 1994 and December 2000 were analysed. The measurements were reviewed by an independent panel of radiologists. Patient characteristics were: median age of 55 years (range 24-77 years) and a male to female ratio of 129 : 35. Adenocarcinoma and squamous carcinoma were the most common histologies. Vinorelbine was the third drug used in 77 patients and gemcitabine in 87. The ratio unidimensional/bidimensional was as follows: response 85 : 85; stable disease 32 : 32; progression 47 : 42 and not assessable 0 : 5. Kappa for agreement between responders was 0.951 (95% CI: 0.795-1.0) (P<0.001). Both WHO criteria and Response Evaluation Criteria In Solid Tumors give similar results in assessing tumour response in patients with non-small cell lung cancer after chemotherapy. The unidimensional measurement could replace the more complex bidimensional one.

Adenocarcinoma↗
PubMed2002

Artichoke cultivars (var. "Blanca de Tudela") under elevated ozone concentrations.

Ozone concentrations rise to phytotoxic levels from spring to autumn at western Mediterranean basin coastal sites, where artichoke is one of the most important crops. Simultaneously, from year to year and especially since the early 1980s, resprouting of the stumps has been decreasing in Valencian Community artichoke plantations. To see if ozone might be playing a role in this decrease, a number of plants were exposed to different levels of ozone. Results of the ozone treatments showed reduced biomass in the offshoots of plants exposed to the highest ozone treatment. The exposure to ambient ozone during the stump-establishment period, when compared to filtered-air conditions, resulted in a reduction in yield when plants were transplanted in the field under ambient ozone concentrations. And when plants were exposed to acute short picks, typical ozone visual injury appeared in the older leaves.

Agriculture↗
PubMed2002

Expression of housekeeping genes during the asexual cell cycle of Plasmodium falciparum.

In an earlier study, we found that calmodulin displayed an atypical expression for a housekeeping gene during the erythrocytic cycle of Plasmodium falciparum. The expression pattern was that of an inducible gene linked to the cell cycle, with a peak prior to replication, and not one of a gene that expresses itself in a constitutive way. In this work, we examined the expression pattern of other housekeeping genes, selecting genes from two functionally very different groups: those for three enzymes involved in carbohydrate metabolism--glucose-phosphate-isomerase (GPI), aldolase and glucose-6-phosphate-dehydrogenase (G6PD)--and for three proteins with structural and motor functions--actin-I, beta-tubulin and myosin. The mRNA of each gene was measured by reverse transcription-polymerase chain reaction in synchronic parasite samples that were 14, 28, 40 and 48 h old. GPI and G6PD achieved their maximum expression at 28 h, then declined, while aldolase increased its expression up to 40 h and remained high, but less so at 48 h. Actin and myosin showed the same pattern, increasing up to 48 h, while beta-tubulin expression peaked at 40 h. These findings confirm unconventional behavior in the expression of certain Plasmodium housekeeping genes and suggest the existence of different expression patterns for distinct functional groups.

Animals↗
PubMed2002

The major acid soluble proteins of adult female Anopheles darlingi salivary glands include a member of the D7-related family of proteins.

The salivary gland proteins of adult female Anopheles darlingi were fractionated by reverse-phase HPLC and the five major peaks were submitted for amino-terminal sequencing using automated Edman degradation. The amino acid sequence of one of the purified salivary gland proteins showed similarity with the D7r3 protein of An. gambiae. Cloning and sequencing of two cDNAs allowed the prediction of the complete sequence of the An. darlingi D7 protein. The D7r3 protein is present specifically in adult female salivary glands of An. darlingi and despite being one of the major salivary gland proteins its function is not known. Predictions of secondary and tertiary structures revealed the similarity of the An. darlingi D7 protein to insect odorant binding proteins. This suggests that D7 proteins may act as carriers of hydrophobic molecules in mosquito saliva.

Amino Acid Sequence↗
PubMed2002

Statistical analysis of high-density oligonucleotide arrays: a multiplicative noise model.

MOTIVATION: High-density oligonucleotide arrays (GeneChip, Affymetrix, Santa Clara, CA) have become a standard research tool in many areas of biomedical research. They quantitatively monitor the expression of thousands of genes simultaneously by measuring fluorescence from gene-specific targets or probes. The relationship between signal intensities and transcript abundance as well as normalization issues have been the focus of much recent attention (Hill et al., 2001; Chudin et al., 2002; Naef et al., 2002a). It is desirable that a researcher has the best possible analytical tools to make the most of the information that this powerful technology has to offer. At present there are three analytical methods available: the newly released Affymetrix Microarray Suite 5.0 (AMS) software that accompanies the GeneChip product, the method of Li and Wong (LW; Li and Wong, 2001), and the method of Naef et al. (FN; Naef et al., 2001). The AMS method is tailored for analysis of a single microarray, and can therefore be used with any experimental design. The LW method on the other hand depends on a large number of microarrays in an experiment and cannot be used for an isolated microarray, and the FN method is particular to paired microarrays, such as resulting from an experiment in which each 'treatment' sample has a corresponding 'control' sample. Our focus is on analysis of experiments in which there is a series of samples. In this case only the AMS, LW, and the method described in this paper can be used. The present method is model-based, like the LW method, but assumes multiplicative not additive noise, and employs elimination of statistically significant outliers for improved results. Unlike LW and AMS, we do not assume probe-specific background (measured by the so-called mismatch probes). Rather, we assume uniform background, whose level is estimated using both the mismatch and perfect match probe intensities. RESULTS: We present a new method for GeneChip analysis, based on a statistical model with multiplicative noise. We demonstrated that this method yields results superior to those obtained by the Affymetrix Microarray Suite 5.0 software and to those obtained by the model-based method of Li and Wong (Li and Wong, 2001). The present method eliminates the hard-to-interpret negative expression indices, and the binary 'presence' calls (present or absent) are replaced by the statistical significance (p-value) of gene expression. We have found that thresholding the p-values at the (0.1)(16)-level produces about the same number of 'present' calls as the AMS software. By testing our method on a pair of replicate GeneChips (hybridized with the same cRNA), we found that 95.6% of data points lie within the 1.25-fold interval. In other words, our method had a 4.4% type I error rate at the 1.25-fold level. The error rate of the LW method was 15%, and that of the AMS method was 29%. There were no points outside the 2-fold interval with the present method. Analysis of variance (ANOVA) of another experiment with multiple replicates shows that this reduction of variance is not accompanied by a corresponding reduction of signal. On the contrary, the signal-to-noise ratio (as measured by the distribution of F-statistics) of the present method is on average 3.4-times better than that of AMS, and 1.4-times better than that of Li and Wong.

Algorithms↗
PubMed2001

Fixed higher dose schedule of suramin plus hydrocortisone in patients with hormone refractory prostate carcinoma a multicenter Phase II study.

BACKGROUND: Using a fixed higher-dose schedule, the efficacy and toxicity of suramin plus hydrocortisone were assessed in patients with metastatic hormone-refractory prostate carcinoma (HRPC). METHODS: Fifty consecutive patients with HRPC (including those in whom hormonotherapy was withdrawn) and an Eastern Cooperative Oncology Group performance status of 0-2 were recruited. Treatment was comprised of a bolus intravenous infusion of 200 mg of suramin followed by suramin (500 mg/m(2) intravenously [i.v.] over 24 hours) given daily over 5 days as a loading course, followed by suramin (350 mg/m(2) i.v. over 2 hours) administered weekly for 12 weeks. This 12-week course was repeated at 6-month intervals. All patients received concomitant hydrocortisone. RESULTS: Five hundred fifty weekly doses of therapy were delivered over the course of the entire study. A partial response, based on a > 50% decrease in the prostate specific antigen (PSA) level, was achieved in 27 patients (54%; 95% confidence interval [95% CI], 44.7-65.0%), 16 of whom (32%; 95%CI, 23.9-43.2%) had a > 75% decrease in their PSA levels. The measurable disease objective response rate was 18% (95% CI, 2.3-51.8%). Of the 37 patients with bone pain requiring analgesia, 27 patients (73%; 95% CI, 55.9-86.2%) reduced their medication consumption to a lower level on the World Health Organization analgesic ladder. The median duration of response was 15.5 weeks (range, 6-70 weeks), the median time to disease progression was 13 weeks, and the median overall survival time was 11 months. Treatment generally was well tolerated. Fatigue and severe lymphopenia were the most commonly reported significant toxicities. In addition, there was 1 septic toxic death reported, and 10% of the patients were found to have NCI Grade 3-4 neurotoxicity. CONCLUSIONS: The results of the current study demonstrated that the fixed-dose suramin regimen administered herein showed high, although short-lived, activity and a good tolerance profile in HRPC patients.

Aged↗
PubMed2001

Coronavirus derived expression systems.

Both helper dependent expression systems, based on two components, and single genomes constructed by targeted recombination, or by using infectious cDNA clones, have been developed. The sequences that regulate transcription have been characterized mainly using helper dependent expression systems and it will now be possible to validate them using single genomes. The genome of coronaviruses has been engineered by modification of the infectious cDNA leading to an efficient (>20 microg ml(-1)) and stable (>20 passages) expression of the foreign gene. The possibility of engineering the tissue and species tropism to target expression to different organs and animal species, including humans, increases the potential of coronaviruses as vectors. Thus, coronaviruses are promising virus vectors for vaccine development and, possibly, for gene therapy.

Coronavirus↗