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Biomedical subjects

A Ferrer

Publications and source records attributed to A Ferrer.

At least 19 recordsLinked to original sources
PubMed1999

[Non-gastric mucosa-associated lymphoid tissue (MALT) lymphomas: analysis of 14 patients].

BACKGROUND: Mucosa-associated lymphoid tissue (MALT) lymphomas are a well defined group of B-cell non-Hodgkin's lymphomas, that arise in a wide variety of extranodal sites, most frequently in the stomach and related to Helicobacter pylori infection. The aim of the present study was to analyze the presenting features, natural history and outcome in 14 patients with non-gastric MALT lymphoma. PATIENTS AND METHODS: The main clinical data, treatment and outcome were recorded for the 14 patients with non-gastric MALT lymphoma diagnosed at a single institution in a 12 year period. The median age was 68 years and 13 patients were females. Diagnosis was made according to the REAL classification criteria. RESULTS: The initial location was thyroid (3 patients), parotid (three), submaxilar gland (three), skin (two), Waldeyer's ring (one), breast (one), lung (one), small bowel (one), liver (one) and ovary (one). At diagnosis 3 patients had > or = 2 extranodal involved sites. Autoimmune disorders were present in 5 patients: Hashimoto's thyroiditis (three), Sjögren's syndrome (one) and both (one). Two patients had a poor performance status (ECOG > 1) and B-symptoms. Five patients (36%) were in stage IV, two of them because of bone marrow infiltration. All patients had a normal serum LDH level, and 5 had high beta 2-microglobulin level. The treatment consisted in surgical resection (2 patients), surgery and radiotherapy (one), surgery and chemotherapy (two), chemotherapy and radiotherapy (two) and chemotherapy alone (7 patients, three of them with doxorubicin-containing regimens). Twelve patients were evaluable for response. Complete response, partial response and failure rates were 75, 17 and 8%, respectively. Two of the 11 responders progressed, one of them with advanced stage disease. The actuarial 4-year disease-free survival was 77% (CI 95%: 47-100%). After a median follow-up of 3.4 years, 100% of the patients were alive. CONCLUSION: Non-gastric MALT lymphomas may be associated with autoimmune disorders, may present as disseminated disease and have a very good outcome.

Adult↗
PubMed1999

Purification and characterization of two alpha-amylases from Toxoplasma gondii.

Two distinct alpha-amylases have been identified in Toxoplasma gondii. They were purified close to homogeneity from cytoplasmic and membrane fractions. The apparent molecular weight of the cytoplasmic amylase was 22,300 Da and that of the membrane enzyme was 39,600 Da by gel filtration, and 25,000 and 41,000 Da by SDS gel electrophoresis, respectively. The physicochemical and catalytic properties of both enzymes showed them to be very different. Cytoplasmic alpha-amylase had an acid isoelectric point and its optimum pH was pH 5.0; its activity was unaffected by NaCl, Ca2+, or EDTA. The membrane alpha-amylase had an isoelectric point of 7.7 and an optimum pH of 8.0. It was affected by Ca2+, inhibited by EDTA, and activated eight-fold by NaCl. Both amylases were inactivated by temperatures above 65 degrees C, but cytoplasmic amylase was more resistant to thermal denaturation.

Animals↗
PubMed1999

Prospective clinical and microbiological study of pleural effusions.

A prospective clinical microbiological study of pleural fluid samples was conducted to investigate the etiology of pleural effusions and to evaluate two different methods for transport and culture of these samples. A total of 245 pleural fluid specimens were inoculated into a transport vial, an aerobic and an anaerobic blood culture vial, and a sterile tube. One hundred nine samples were from infectious patients and 128 from noninfectious patients. Gram stain had a sensitivity of 48% and a specificity of 100% as compared to culture. Of the total, 15.5% of the samples were positive for microorganisms, and 60% of the positive samples were nonpurulent pleural fluid. Single-organism growth was found in 23 samples (60.5%). Sixty-three microorganisms were isolated: 25 (39.7%) aerobic, 22 (35%) anaerobic, 13 (20.6%) mycobacteria, and three (4.7%) fungi. Of the 25 positive samples, excluding those samples that grew mycobacteria, nine (36%) were positive exclusively in the blood culture vials. Twelve organisms were isolated, only one of which did not grow in the anaerobic vial. Two (8%) samples were positive by conventional culture only, and 14 (56%) were positive by both methods. The microorganism isolation rate obtained with use of blood culture vials was significantly greater than that obtained with the conventional method of transport and culture. Sixty-three percent of the empyema patients had an associated underlying pathology, pneumonia being the most frequent. In conclusion, for microbiological study of pleural fluid, it seems appropriate to inoculate all samples, including nonpurulent samples, into both a sterile tube and an anaerobic blood culture vial.

Adolescent↗
PubMed1999

[Prevalence of chronic bronchitis, asthma and airflow limitation in an urban-industrial area of Catalonia].

OBJECTIVES: To determine the prevalence of chronic bronchitis, asthma and airflow limitation in the general population of the urban-industrial area in and around the town of Sabadell (Catalonia, Spain), and to assess its degree of association with smoking and exposure to secondhand smoke. METHODS: Transversal study of 642 men and women between 20 and 70 years of age listed on census rolls. The standardized questionnaire of the American Thoracic Society was used to interview 576 subjects (90%). Tests of forced spirometry with bronchodilation were administered to 497 individuals (77%). RESULTS: The prevalence of chronic bronchitis was 11.6% (21% of men and 2.7% of women). Asthma had been diagnosed by a subject's doctor in 3.3% of the sample (2.1% of men and 4.4% of women). The prevalence of several asthma-related symptoms was higher. Dyspnea with wheezing was reported by 10.6% of the population (11.4% of men and 9.8% of women); wheezing within the past year was reported by 38.2% (45.4% of men and 31.4% of women). The prevalence of airflow limitation (defined as FEV1 < 80% with an FEV1/FVC index < 70%) in the population sample was 7.2% (10.4% of men and 4.1% of women); in men aged 60 to 70 years, however, the prevalence was 30.8%. Exposure to secondhand smoke was related to the presence of chronic coughing (OR = 4.6) and wheezing (OR = 1.8), but not to significant spirometric changes. CONCLUSIONS: The prevalence of respiratory symptoms and airflow limitation is high in our area, particularly among men and older patients (60 to 70 years old). Like active smokers and ex-smokers, subjects who have been exposed to secondhand smoke are at greater risk of developing respiratory symptoms.

Adult↗
PubMed1999

Tuberculosis infection and disease among schoolchildren: the influence of the HIV epidemic and of other factors.

BACKGROUND: The HIV/AIDS epidemic has caused an excess of tuberculosis cases in Spain and in other countries, but its impact on tuberculosis infection is less well understood. This study presents a massive screening undertaken to estimate the prevalence of tuberculous infection in a cohort of primary school entrants. The evolution of the risk of infection is studied by comparison with previous data in the same population. METHODS: Tuberculin skin test screening with 2TU of PPD RT 23 of first grade students in the primary schools of Barcelona, in the 1994-95 school year (cohort born in 1988). Information was also sought from families of unscreened children. Contacts of PPD+ children were traced to locate index cases. The results were also linked to the case registry of the tuberculosis control programme. RESULTS: The prevalence of tuberculin reactors free of BCG vaccination among the 11,080 schoolchildren screened belonging to the 1988 cohort was 0.76%. A 3% annual decline in the annual risk of infection is estimated by comparison with previous data. The identification of 24 cases with a previous history of tuberculosis disease and of 13 cases with active disease diagnosed after the screening was possible by the follow up of these tuberculin positive children and of the information provided by families of unscreened pupils. The screening detected 1.5 new cases of tuberculosis per 1000 tuberculin tests performed. Tuberculosis infection could be traced to HIV infected tuberculosis cases for at least 6% of the positive schoolchildren. CONCLUSIONS: The decline of the annual risk of infection continues in Barcelona, although at a slower pace than before the HIV/AIDS epidemic, probably attributable to the influence of injecting drug users with smear positive tuberculosis and HIV/AIDS.

Child↗
PubMed1999

The changing profile of Ph-positive chronic myeloid leukemia at presentation: possible impact of earlier diagnosis on survival.

BACKGROUND AND OBJECTIVE: Although there are indications that the profile of chronic myeloid leukemia (CML) at presentation has changed in recent years, information is scarce. The objective of the present study was to ascertain whether the initial features of CML have changed over time, as well as the possible impact on survival. DESIGN AND METHODS: The initial features of 167 patients diagnosed with chronic phase Ph-positive CML from 1972 to 1985 were compared with those of 174 such patients diagnosed at the same institution from 1985 to 1998. The survival of the two groups was also compared. RESULTS: CML patients diagnosed since 1985 were significantly older at presentation (mean age 47+17 vs 43+17 years, p = 0.04), were more often asymptomatic (36% vs 19%, p = 0.0003), less often had constitutional symptoms (30% vs 45%, p = 0.004), less frequently had splenomegaly (59% vs 75%, p = 0.0008) and hepatomegaly (35% vs 49%, p = 0.01), had less marked leukocytosis (mean WBC count 139+/-124x10(9)/L vs 179+/-132x10(9)/L, p = 0.007), with 30% of them showing an initial WBC count below 50x10(9)/L (vs 19%, p = 0.02), and showed less marrow blast cell infiltration (p = 0.0003). No significant differences were observed in the distribution by Sokal's risk groups. Median survival of patients diagnosed since 1985 was 5. 33 years (95% CI: 4.3-6.36), vs 4.06 years (95% CI: 3.28-4.84) for patients diagnosed before (p = 0.07). Finally, patients asymptomatic at diagnosis had a longer survival (median survival 5.7 years, 95% CI: 4.5-6.9, vs 4.1 years, 95% CI: 3.4-4.7, p = 0.03). INTERPRETATION AND CONCLUSIONS: A substantial proportion of CML patients are currently diagnosed early in the course of the disease. The effect of earlier diagnosis on survival prolongation in such patients should be taken into account.

Adult↗
PubMed1998

Molecular cloning and characterization of two phosphatase 2A catalytic subunit genes from Arabidopsis thaliana.

The plant Arabidopsis thaliana contains five isoforms of the catalytic subunit of protein phosphatase 2A (PP2A) that can be grouped into two families, one composed by isoforms PP2A-1, -2 and -5 and the other composed by isoforms PP2A-3 and PP2A-4. An Arabidopsis genomic library was screened and several clones corresponding to genes PP2A-3 and PP2A-4 were isolated and analysed. Both genes span over approximately 4.5kbp and are composed of 11 exons and 10 introns that show identical organization. Their untranslated regions are also highly conserved, suggesting that the two genes derive from a common ancestral gene. However, the position of intron/exon junctions completely differs from that of the human PP2A genes. Two transcription start sites have been found in the PP2A-3 gene, the major one mapping at nucleotide position -188 from the translation start codon, whereas only one is observed in PP2A-4 (-145). Functional gene promoter analysis reveals that elements required for transient expression of PP2A-3 and PP2A-4 on a protoplast system are contained within a region of about 600bp upstream from the transcription start sites. This is the first report on the cloning and characterization of genes encoding catalytic subunits of Ser/Thr protein phosphatases 2A in higher plants.

Amino Acid Sequence↗
PubMed1998

Cerebral hemodynamic changes during sustained hypocapnia in severe head injury: can hyperventilation cause cerebral ischemia?

Hyperventilation (HV) is routinely used in the management of increased intracranial pressure (ICP) in severe head injury. However, this treatment continues to be controversial because it has been reported that long-lasting reduced cerebral blood flow (CBF) due to profound sustained hypocapnia may contribute to the development or deterioration of ischemic lesions. Our goal in this study was to analyze the effects of sustained hyperventilation on cerebral hemodynamics (CBF, ICP) and metabolism (arterio jugular differences of lactates = AVDL). CO2-reactivity and CBF was estimated using AVDO2 (arteriojugular differences of oxygen content). Global cerebral ischemia and increased anaerobic metabolism were considered according to AVDO2 and AVDL respectively. Thirty-three patients with severe and moderate head injury and increased ICP were included. Within 72 hours after accident, patients were hyperventilated for a period of 4 hours. During this time jugular oxygen saturation (SjO2), arterial oxygen saturation (SaO2), ICP, mean arterial blood pressure (MABP), AVDO2 and AVDL were recorded. In our study, most patients preserved CO2-reactivity (88.2%). In these cases HV was very effective in lowering ICP. Our findings showed that this reduction was due to a CBF decrease. According to basal AVDO2 twenty-five patients (75.7%) were considered as hyperemic and eight (24.2%) as not hyperemic. Global ischemia and increased anaerobic metabolism were detected in one case in the non-hyperemic group. According to AVDO2 and AVDL, no adverse effects were found during four hours of HV in hyperemic patients. Nevertheless, AVDO2 and AVDL are global measurements and might not detect regional ischemia surrounding focal lesions such as contusions and haematomas. We suggest that monitoring of AVDO2 or other haemometabolic variables should be mandatory when sustained HV is used in the management of head injury patients.

Adolescent↗
PubMed1998

Short- and long-term action of multiple doses of ivermectin on loiasis microfilaremia.

One hundred nine Gabonese patients infected with Loa loa microfilariae were treated with ivermectin (200 microg/kg of body weight) at the Parasitology, Mycology and Tropical Medicine Department (Faculte de Medecine et des Sciences de la Sante, Libreville, Gabon). Each was given one dose per month for six consecutive months. The peripheral blood microfilaria (mf) count before and after each dose showed an average decrease in the microfilaremia of 87.3% (short-term-single dose). An annual single-dose mass treatment with 200 microg/kg of ivermectin was sufficient to control the parasite in populations with low (< 400/ml) L. loa mf counts. One month after the sixth dose (short-term-multiple doses), the average microfilaremia rate had decreased by 99.2% compared with the initial infection (35 patients). Samples were taken from 28 patients one month after the first dose and one month after the sixth dose. The average mf count decreased by 96.4% after the first dose and by 99.6% after the sixth dose (average residual mf counts = 13.7 and 1.5 mf/ml, respectively). The mf count after the sixth dose was only 11.2% of the count after the first dose. The low mf count persisted for more than six months after the sixth treatment (long-term-multiple doses). Thus, mass treatment with multiple doses is more appropriate for areas where the blood mf count is very high. These results show that the number of the annual treatments used in mass chemotherapy with ivermectin can be adapted to each population to provide efficient protection.

Adolescent↗
PubMed1997

Cloning and characterization of the Arabidopsis thaliana SQS1 gene encoding squalene synthase--involvement of the C-terminal region of the enzyme in the channeling of squalene through the sterol pathway.

Squalene synthase (SQS) catalyzes the first committed step of the sterol biosynthetic pathway. A full-length Arabidopsis thaliana SQS cDNA has been isolated by combining library screening and PCR-based approaches. Arabidopsis SQS is encoded by a small gene family of two genes (SQS1 and SQS2) which are organized in a tandem array. SQS1 and SQS2 have an identical organization with regard to intron positions and exon sizes and encode SQS isoforms showing a high level of sequence conservation (79% identity and 88% similarity). The isolated cDNA has been assigned to the SQS1 gene product, SQS1. RNA blot analysis has shown that the 1.6-kb SQS1 mRNA is detected in all plant tissues analyzed (inflorescenses, leaves, stems and roots) although the transcript is especially abundant in roots. Arabidopsis SQS1 isoform is unable to complement the SQS-defective Saccharomyces cerevisiae strain 5302, although SQS activity was detected in the microsomal fraction of the transformed yeast strain. However, a chimeric SQS resulting from the replacement of the 66 C-terminal residues of the Arabidopsis enzyme by the 111 C-terminal residues of the Schizosaccharomyces pombe enzyme was able to confer ergosterol prototrophy to strain 5302. Labeling studies using [3H]farnesyl-P2 and microsomal fractions obtained from yeast strains expressing either Arabidopsis SQS1 or chimeric Arabidopsis/S. pombe SQS derivatives indicated that the C-terminal region of the enzyme is involved in the channeling of squalene through the yeast sterol pathway.

Amino Acid Sequence↗
PubMed1997

Three spinach leaf nitrate reductase-3-hydroxy-3-methylglutaryl-CoA reductase kinases that are regulated by reversible phosphorylation and/or Ca2+ ions.

In spinach (Spinacea oleracea L.) leaf extracts, three protein kinases (PKI, PKII and PKIII) were identified each of which phosphorylated spinach nitrate reductase on serine-543, and inactivated the enzyme in the presence of nitrate reductase inhibitor, 14-3-3. PKIII was also very active in phosphorylating and inactivating Arabidopsis (Landsberg erecta) 3-hydroxy-3-methylglutaryl-coenzyme A reductase 1 (HMGR1). PKI and PKII phosphorylated HMGR1 more slowly than PKIII, compared with their relative rates of phosphorylation of nitrate reductase. HMGR1 identical with those that are seen after phosphorylation of serine-577 by the sucrose non-fermenting (SNF1)-like PK, 3-hydroxy-3-methylglutaryl-Co A reductase kinase A (HRK-A), from cauliflower [Dale, Arró, Becerra, Morrice, Boronat, Hardie and Ferrer (1995) Eur. J. Biochem. 233, 506-513]. PKI was Ca2+-dependent when prepared in the absence of protein phosphatase (PP) inhibitors, and largely Ca2+-dependent when prepared in the presence of PP inhibitors (NaF and EGTA). The Ca2+-independent portion of PKI was inactivated by either PP2A or PP2C, while the Ca2+-dependent portion of PKI became increasingly activated during storage, which we presume was mimicking the effect of an unidentified PP. These findings indicate that PK1 is regulated by two functionally distinct phosphorylations. PKI had a molecular mass of 45 kDa on gel filtration and was active towards substrate peptides that terminated at the +2 residue from the phosphorylation site, whereas PKIII was inactive towards these peptides. PKII was Ca2+-stimulated under all conditions tested. PKIII was Ca2+-indepdented, inactivated by PP2A or PP2C, had a requirement for a hydrophobic residue in the +4 position of peptide substrates, had a molecular mass by gel filtration of approximately 140 kDa, and an antibody against the rye SNF1-related PK (RKIN1) recognized a 58 kDa subunit in fractions containing PKIII. These properties of PKIII are identical with those reported previously for the SNF1-like enzyme, HRK-A. Our results indicate a considerable complexity of kinase cascades mediating the regulation of assimilatory and biosynthetic pathways in response to environmental stimuli in plants.

Amino Acid Sequence↗
PubMed1997

The Arabidopsis thaliana FPS1 gene generates a novel mRNA that encodes a mitochondrial farnesyl-diphosphate synthase isoform.

The enzyme farnesyl-diphosphate synthase (FPS; EC 2.5.1.1./EC 2.5.1. 10) catalyzes the synthesis of farnesyl diphosphate from isopentenyl diphosphate and dimethylallyl diphosphate. FPS is considered to play a key role in isoprenoid biosynthesis. We have reported previously that Arabidopsis thaliana contains two differentially expressed genes, FPS1 and FPS2, encoding two highly similar FPS isoforms, FPS1 and FPS2, (Cunillera, N., Arró, M., Delourme, D., Karst, F., Boronat, A., and Ferrer, A. (1996) J. Biol. Chem. 271, 7774-7780). In this paper we report the characterization of a novel Arabidopsis FPS mRNA (FPS1L mRNA) derived from the FPS1 gene. A cDNA corresponding to the FPS1L mRNA was cloned using a reverse transcription-polymerase chain reaction strategy. Northern blot analysis showed that the two FPS1-derived mRNAs are differentially expressed. The FPS1L mRNA accumulates preferentially in inflorescences, whereas the previously reported FPS1 mRNA (FPS1S mRNA) is predominantly expressed in roots and inflorescences. FPS1L mRNA contains an in-frame AUG start codon located 123 nucleotides upstream of the AUG codon used in the translation of the FPS1S isoform. Translation of the FPS1L mRNA from the upstream AUG codon generates a novel FPS1 isoform (FPS1L) with an NH2-terminal extension of 41 amino acid residues, which has all the characteristics of a mitochondrial transit peptide. The functionality of the FPS1L NH2-terminal extension as a mitochondrial transit peptide was demonstrated by its ability to direct a passenger protein to yeast mitochondria in vivo and by in vitro import experiments using purified plant mitochondria. The Arabidopsis FPS1L isoform is the first FPS reported to contain a mitochondrial transit peptide.

Alkyl and Aryl Transferases↗
PubMed1997

From clinical trials to clinical practice: oral anticoagulation among patients with non-rheumatic, atrial fibrillation.

OBJECTIVES: The aim of the present study was to evaluate the impact of the results of clinical trials on the prophylactic treatment of non-rheumatic atrial fibrillation with oral anticoagulants. METHODS: Retrospectively, we studied a random sample of 375 patients discharged from our hospital with a diagnosis of non-rheumatic atrial fibrillation between 1991 and 1993. Information about diagnoses, other clinical variables and treatments prescribed at discharge was obtained from the hospital medical records. RESULTS: During the whole study period, 14% of patients were prescribed an oral anticoagulant agent and 17% were prescribed acetylsalicylic acid. A non-significant increase in the proportion of patients prescribed oral anticoagulant drugs, from 9% to 17%, was observed. Multivariate analysis showed that a history of stroke (OR = 5.96) and younger age were significantly associated with the prescription of oral anticoagulants. ASA prescription was strongly associated with a history of concomitant vascular disease (OR = 5.8), but not with other risk factors for stroke. Sixty-five percent of patients had one or more risk factors for stroke, did not present any contraindications to anticoagulant agents, but nevertheless were not prescribed one of these drugs. CONCLUSIONS: Anticoagulant agents and acetylsalicylic acid were largely underprescribed to patients with non-rheumatic atrial fibrillation, and oral anticoagulants were not prescribed according to the individual patients' risk of stroke.

Acenocoumarol↗
PubMed1997

Photochemistry of water-soluble quinones. Production of a water-derived spin adduct.

The photolyses of phosphate-buffered (pH 7) air- and nitrogen-saturated solutions containing the water-soluble quinones, 1,4-benzoquinone (BQ), 2-methyl-1,4-benzoquinone (MBQ), sodium 1,4-naphthoquinone-2-sulfonate (NQ2S), 9,10-anthraquinone-2-sulfonate (AQ2S) or 9,10-anthraquinone-1,5-disulfonate (AQDS), and the spin trap 5,5-dimethylpyrroline-1-oxide (DMPO) produce a DMPO-OH adduct. Electron paramagnetic resonance spectroscopy of the photolyzed samples in 17O-enriched water demonstrates that this adduct derives almost exclusively from water. With the exception of BQ, quantum yields for the formation of DMPO-OH are larger in air than in nitrogen-saturated samples, thus supporting the idea of the formation of air-oxidized intermediates that enhance the DMPO hydroxylation reaction rate. Evidence has been obtained which suggests that BQ and MBQ, but not AQDS, are able to photooxidize water, with the consequent production of the free OH radical.

Cyclic N-Oxides↗