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Biomedical subjects

J Ferrer

Publications and source records attributed to J Ferrer.

At least 55 records · Page 3Linked to original sources

Heterologous overexpression of glucose dehydrogenase from the halophilic archaeon Haloferax mediterranei, an enzyme of the medium chain dehydrogenase/reductase family.

The first gene encoding a glucose dehydrogenase (GDH) from a halophilic organism has been sequenced. Amino acid sequence alignments of GDH from Haloferax mediterranei show a high degree of homology with the thermoacidophilic GDHs and with other enzymes from the medium chain dehydrogenase/reductase family. Heterologous overexpression using the mesophilic organism Escherichia coli as the host has been performed and the expression product was obtained as inclusion bodies. To obtain the halophilic enzyme in its native form refolding and reactivation in a saline environment were required. A pure and highly concentrated sample of the enzyme was obtained using a purification procedure based on the protein's halophilicity. This method may be useful as a general procedure for purifying other halophilic proteins from mesophilic hosts.

Amino Acid Sequence↗

The detection of Tel-TrkC chimeric transcripts is more specific than TrkC immunoreactivity for the diagnosis of congenital fibrosarcoma.

The t(12;15)(p13;q25) translocation, a recurrent chromosomal abnormality of congenital fibrosarcoma, leads to the expression of a Tel-TrkC fusion transcript. To determine whether detection of the chimeric protein may be helpful for the diagnosis of congenital fibrosarcoma, immunohistochemistry was performed with an anti-TrkC antibody on 26 spindle cell tumours of newborn or young children (n=19) or adults (n=7). Four out of five congenital fibrosarcomas showed TrkC immunoreactivity with cytoplasmic paranuclear staining. However, TrkC immunoreactivity was not restricted to congenital fibrosarcoma and was observed in infantile myofibromatosis, congenital haemangiopericytoma, desmoid tumour, nodular fasciitis, fibrous hamartoma, inflammatory myofibroblastic tumour, and adult fibrosarcoma. RT-PCR analysis was performed on nine cases, including four congenital fibrosarcomas, for which frozen material was available. Tel-TrkC transcripts were detected by RT-PCR in the four congenital fibrosarcomas analysed, but not in the five other spindle cell tumours. Furthermore, several Tel-TrkC transcripts encoding for kinase isoforms of the Tel-TrkC protein were detected in congenital fibrosarcoma and may be involved in oncogenesis. The reciprocal TrkC-Tel transcript was detected in only one congenital fibrosarcoma. While the detection of a Tel-TrkC fusion transcript is a recurrent feature of congenital fibrosarcoma, TrkC immunoreactivity does not appear specific for the diagnosis of fibromatous paediatric tumours.

Adult↗

Genetic variability of the SUR1 promoter in relation to beta-cell function and Type II diabetes mellitus.

AIMS/HYPOTHESIS: We aimed to examine the promoter of SUR1 for genetic variation and to determine if variants were associated with Type II (non-insulin-dependent) diabetes mellitus or measures of beta-cell function. METHODS: We examined 465 bp upstream of the ATG site in 46 Type II diabetic patients and 15 glucose tolerant control subjects by SSCP-heteroduplex analysis. RESULTS: We identified an a --> t substitution 437 bp upstream of the ATG site. The allelic frequency was similar in 455 unrelated Type II diabetic patients and in 203 glucose tolerant control subjects matched for age (0.036, [95 % CI 0.019-0.053] vs 0.034 [95 % CI 0.009-0.059]; p = 0.92). Among the glucose tolerant subjects there were no differences between non-carriers (n = 189) and carriers (n = 14) of the variant in fasting values or 30 min values of plasma glucose and serum insulin during an oral glucose tolerance test. In a study of 233 glucose tolerant offspring of and spouses to Danish Caucasian Type II diabetic patients, non-carriers (n = 193) and carriers (n = 37) of the -437 a/t polymorphism did not differ in glucose or tolbutamide stimulated insulin response during an intravenous glucose tolerance test with intravenous tolbutamide injection [AUCs-insulin (0-8) min, 2290 +/- 1660 vs 2308 +/- 1935 pmol/l x min and AUCs-insulin(20-30 min), 3113 +/- 2033 vs. 3393 +/- 2830 pmol/l x min, respectively]. CONCLUSION/INTERPRETATION: We have identified a novel a/t polymorphism of the SUR1 gene promoter which is not associated with Type II diabetes mellitus or measures of beta-cell function. Previous reported non-functional variants of SUR1 associated with Type II diabetes mellitus still need to be accounted for.

ATP-Binding Cassette Transporters↗

Agronomic use of biotechnologically processed grape wastes.

Grape waste was composted by biodegradation and subsequently used as an organic fertilizer for 20 day-corn. Combinations of recently compressed grape waste and hen droppings (10% w/w) were prepared to study the activating effect of hen droppings and the effect of aeration on the composting process. The final hydrogen potential (pH), %C, %N and C/N ratio, indicated an adequate development of the bioprocess. Satisfactory results were observed when the products were applied at several doses (1,000-4,000 kg/ ha) as a soil conditioner for corn seed germination in greenhouses. Only the addition of hen droppings had a significant effect (P < 0.05) on corn dry matter (14% increase). A dose of 3000 kg/ha was considered as optimal and was used supplemented with triple superphosphate (TSP) in agronomic trials. All the treatments produced greater corn dry matter (P < 0.05) than the chemical industrial fertilizer used as a control (0.52-0.71 g/pot for the organic fertilizers vs 0.45 g/pot for the control). Anaerobic conditions and hen droppings addition significantly produced (P < 0.05) higher corn dry matter.

Biodegradation, Environmental↗

Prevalence and risk indicators for destructive periodontal diseases in 3 urban American minority populations.

BACKGROUND, AIMS: Destructive periodontal diseases have been reported disproportionately more prevalent and severe in African-Americans relative to other American populations. Differences in subgingival microbiota and host immune response have also been reported for African-Americans, implying that risk factors for disease progression may also differ for these populations. Since it is not clear whether these differences are truly genetic or due to confounding variables such as social economic status, we examined a series of clinical, environmental, demographic, and microbiologic features associated with periodontal disease status in a group of 185 urban minority subjects resident within the greater New York metropolitan area. METHODS: The study population consisted of 56 Asian-American, 71 African-American and 58 Hispanic subjects. Clinical data recorded included pocket depth, attachment level, gingival erythema, bleeding upon probing, suppuration, and the presence of supragingival plaque. Environmental and demographic data recorded included smoking history, years resident in the United States, whether the subject reported a private dentist and occupational status. Subgingival plaque was sampled from the mesial aspect of all teeth exclusive of third molars and the levels of 40 subgingival species enumerated using checkerboard DNA-DNA hybridization. RESULTS: The African-American group had more missing teeth, deeper periodontal pocket depth and more attachment loss than the Asian-American or Hispanic groups. However, the African-American group were less likely to report having a private dentist, had a greater proportion of smokers and a greater proportion of unskilled individuals. The profile of subgingival species differed among the three ethnic/racial groups with A. actinomycetemcomitans, N. mucosa, S. noxia and T. socranskii significantly elevated in the Asian-American group and P. micros significantly elevated in the African-American group. When subset by occupational status, numbers of missing teeth, pocket depth, attachment level and prior disease activity were all found increased in the unskilled relative to the professional group. Local factors including the mean % of sites with plaque, marginal gingival erythema, bleeding upon probing and suppuration were also elevated in the unskilled group. The microbial profile differed among the 3 occupational groups with the unskilled group having elevated numbers of species associated with destructive periodontal diseases. CONCLUSIONS: Although greater destructive periodontal disease prevalence and severity were found in the African-American group, these results suggest that environmental and demographic variables, such as occupational status, may have a greater influence on risk indicators associated with disease prevalence and progression in these populations.

Adult↗

Tuberculous pleural effusion and tuberculous empyema.

Tuberculous pleuritis has increased worldwide, especially in developing countries, as a consequence of human immunodeficiency virus co-infection. Tuberculous pleuritis is a delayed hypersensitivity reaction against mycobacterial antigens in the pleural space. Mycobacteria are detected in less than 50% of pleural samples, but the characteristic pleural involvement, granulomas with or without caseous necrosis, is evident in 56 to 80% of cases from samples obtained by percutaneous pleural biopsy. Of several pleural fluid parameters studied, adenosine deaminase and interferon gamma (IFN-gamma) have the best diagnostic yield, while polymerase chain reaction remains a promising test. Treatment of patients with tuberculous pleuritis is discussed. Tuberculous empyema is a rare form of tuberculous pleuritis. It consists of a purulent infection of the pleural cavity with detectable bacilli in pleural fluid. Diagnosis is easily established clinically and bacteriologically. Treatment is to adequately drain the pleural space and achieve lung reexpansion, in conjunction with antituberculous chemotherapy. The efficacy of different surgical techniques is discussed.

Journal Article↗

Evaluation of Activated Sludge Model No. 2 at high phosphorus concentrations.

This paper presents laboratory scale experimentation carried out to study enhanced biological phosphorus removal at high phosphorus concentrations in a sequencing batch reactor. Four series of data obtained in a sequencing batch reactor are examined in light of the Activated Sludge Model No. 2. This model was calibrated using data from the first and second series working at low phosphorus concentrations. The Activated Sludge Model No. 2 successfully characterised the enhanced biological phosphorus removal performance of the sequencing batch reactor at low phosphorus concentrations. The calibrated model was then used to adjust experimental results of the other series working at high phosphorus concentration. Differences between model predictions and experimental data could be explained by redissolution in the anaerobic phase and precipitation in the aerobic phase of calcium phosphates not taken into account by the model. This hypothesis can be justified by the conditions of pH and phosphorus concentration prevailing in the experiments and it was confirmed by the results of another experiment in which precipitated phosphorus profile was measured during the cycle.

Bioreactors↗

Hepatic nuclear factor 1-alpha directs nucleosomal hyperacetylation to its tissue-specific transcriptional targets.

Mutations in the gene encoding hepatic nuclear factor 1-alpha (HNF1-alpha) cause a subtype of human diabetes resulting from selective pancreatic beta-cell dysfunction. We have analyzed mice lacking HNF1-alpha to study how this protein controls beta-cell-specific transcription in vivo. We show that HNF1-alpha is essential for the expression of glut2 glucose transporter and L-type pyruvate kinase (pklr) genes in pancreatic insulin-producing cells, whereas in liver, kidney, or duodenum tissue, glut2 and pklr expression is maintained in the absence of HNF1-alpha. HNF1-alpha nevertheless occupies the endogenous glut2 and pklr promoters in both pancreatic islet and liver cells. However, it is indispensable for hyperacetylation of histones in glut2 and pklr promoter nucleosomes in pancreatic islets but not in liver cells, where glut2 and pklr chromatin remains hyperacetylated in the absence of HNF1-alpha. In contrast, the phenylalanine hydroxylase promoter requires HNF1-alpha for transcriptional activity and localized histone hyperacetylation only in liver tissue. Thus, different HNF1-alpha target genes have distinct requirements for HNF1-alpha in either pancreatic beta-cells or liver cells. The results indicate that HNF1-alpha occupies target gene promoters in diverse tissues but plays an obligate role in transcriptional activation only in cellular- and promoter-specific contexts in which it is required to recruit histone acetylase activity. These findings provide genetic evidence based on a live mammalian system to establish that a single activator can be essential to direct nucleosomal hyperacetylation to transcriptional targets.

Acetylation↗

Ventilatory insufficiency due to asbestos-related diffuse pleural fibrosis successfully treated with noninvasive home mechanical ventilation.

A 54-year-old man with diffuse pleural fibrosis due to previous asbestos exposure developed hypercapnic respiratory failure. Noninvasive mechanical ventilation (NIMV) was started at the hospital and maintained at the patient's home, achieving reversal of the respiratory failure. During a 2-year follow-up, NIMV has been well tolerated by the patient and no relapse in ventilatory failure has occurred. Home NIMV can be considered as an alternative to pleural decortication in asbestos-related diffuse pleural fibrosis with ventilatory insufficiency.

Asbestos↗

Integrated analysis for pre-sorting and waste collection schemes implemented in Spanish cities.

Over recent years, European cities have been questioning their traditional pre-sorting and waste collection practices and looking for new schemes to improve environmental problems generated by waste disposal. This paper presents an integral methodology for four pre-sorting practices that are beginning to be implemented in Spanish cities. A great effort has been made to compile information to be able to estimate a large number of valuation indexes. Based on this information, the methodology is supported by the forecasting of waste generation, the use of GIS techniques, the definition of objectives and their evaluation taking into account legal, social, performance, environmental and economic issues. Special attention is given to environmental impact, for which life cycle assessment methodology is used.

Cities↗

Regulated expression of adenosine triphosphate-sensitive potassium channel subunits in pancreatic beta-cells.

The regulation of glucose-dependent insulin secretion in pancreatic beta-cells is linked to the expression and function of the ATP-sensitive potassium channel (K(ATP)), which is composed of a sulfonylurea receptor (SUR1) and an inwardly rectifying potassium channel (Kir6.2). Previous animal and human genetic studies have demonstrated that disruption or defective expression of K(ATP) subunit genes has a profound impact on the regulation of insulin secretion. Little is known about how SUR1 and Kir6.2 gene expression is regulated. Here we show that high glucose concentrations lead to a marked decrease (approximately 70%) in Kir6.2 messenger RNA (mRNA) levels in isolated rat pancreatic islets as well as in the INS-1 beta-cell line. This effect is reversible, because exposure to low glucose reinduces Kir6.2 transcript levels. The cognate K(ATP) channel subunit SUR1 showed similar down-regulation at high glucose concentration. The K(ATP) channel activity of INS-1 cells cultivated at high glucose was reduced by 33-51%. In contrast, glucagon-like peptide-1 (GLP-1) induced Kir6.2 mRNA steady state levels and was able to prevent glucose-dependent inhibition of Kir6.2 mRNA and K(ATP) channel activity. To provide further insight into the mechanisms by which glucose and GLP-1 regulate beta-cell K(ATP) channel genes, we have cloned and initiated the characterization of the Kir6.2 gene transcriptional regulatory regions contained within the entire 4.5 kb flanked by the SUR1 and Kir6.2 genes. Transient transfection experiments with five deletion constructs in a pancreatic beta-cell line (INS-1) showed that the proximal 988 bp of the Kir6.2 promoter sequence contributes only 25-30% to the total basal promoter activity. The minimal promoter region -67/+140, also encompassing parts of the 5'-untranslated region, confers sensitivity to GLP-1, which stimulates transcriptional activity of the Kir6.2 minigene by about 2-fold. We propose that glucose- and GLP-1-dependent regulation of K(ATP) subunit genes may be important in the adaptation of beta-cells to changes in secretory demands in physiological and diseased states.

ATP-Binding Cassette Transporters↗

Talc preparations used for pleurodesis vary markedly from one preparation to another.

BACKGROUND: At the present time, talc is the one of the agents most commonly used for the production of a pleurodesis. However, there have been several recent reports of acute pneumonitis developing after the intrapleural administration of talc. The incidence of pneumonitis has varied markedly from center to center. OBJECTIVE: To compare the physical characteristics of talc used for the production of pleurodesis in various localities. DESIGN: Eight talc preparations (four from the United States, and one each from Brazil, France, Spain, and Taiwan) were analyzed for the distribution of the particle size and the type and amount of impurities. MEASUREMENTS: The physical characteristics of the talc specimens were determined using radiograph diffraction and scanning electron microscopy. RESULTS: The mean and median particle size varied by more than a factor of three among the eight different talc preparations. In addition, the impurities of the different talc preparations were quite varied. CONCLUSIONS: We conclude that there is marked variation in the physical characteristics of the talc preparations used intrapleurally for the production of a pleurodesis. We speculate that different incidences of acute pneumonitis at various centers after intrapleural administration of talc may be due to differences in the physical characteristics of the talc preparations used for pleurodesis.

Pleurodesis↗

Plasma beta-endorphin levels in obese and non-obese patients with polycystic ovary disease.

The aim of this study was to determine the influence of body weight on circulating plasma levels of beta-endorphin and insulin in women with polycystic ovary disease (PCOD), as well as the correlation between the plasma levels of beta-endorphin and insulin. One-hundred and sixty-seven consecutive subjects with PCOD were recruited, 117 of whom had normal weight (body mass index (BMI) < 25) while 50 were obese (BMI > 25). A venous blood sample was taken and plasma concentrations of beta-endorphin, insulin, gonadotropins, prolactin, progesterone, 17 beta-estradiol, estrone, androgens, dehydroepiandrosterone sulfate and sex hormone-binding globulin (SHBG) were measured. Mean beta-endorphin and insulin plasma levels were significantly higher (p < 0.05) in obese PCOD women than in non-obese ones. Correlation analysis showed a positive association between insulin and beta-endorphin, beta-endorphin and BMI (and weight), insulin and BMI (and weight), and a negative correlation was found between insulin and SHBG. A weak association was found between beta-endorphin and luteinizing hormone (LH) in peripheral plasma. Stratified and linear regression analysis showed that plasma beta-endorphin concentrations correlate more with BMI than with insulinemia.

Adolescent↗

A modification to the Activated Sludge Model No. 2 based on the competition between phosphorus-accumulating organisms and glycogen-accumulating organisms.

A modification to the ASM2 is proposed which permits representation of the competition between phosphorus accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) in a nutrient removal activated sludge system. Some important aspects, which are not considered in ASM2, are discussed. The proposed modification includes denitrification by PAOs, PAO glycogen storage capability and GAO metabolism model. It is shown that the proposed modification is capable of describing pilot plant data using a single set of stoichiometric and kinetic parameters over three different sludge ages (16, 14 and 12 days). The modified ASM2 may be applicable to a wide range of situations where PAOs and GAOs can compete. This modification may well provide a better understanding about GAO behaviour.

Aerobiosis↗

Actin cytoskeleton in adults and metacercariae of Brachylaima sp.

Experimental adults and natural metacercariae of Brachylaima sp. (Digenea: Brachylaimidae) were processed for transmission and scanning electron microscopy, for tetramethyl rhodamine isothiocyanate phalloidin fluorescence, conventional and confocal microscopy and for monoclonal anti-actin antibody immunoelectron microscopy, to describe the ultrastructural features of the tegument and to localize actin in several regions of the body. The general body tegument is spinous and contains membrane-bound disc-shaped biconcave vesicles in adults and metacercariae. Spines are flat and apically indented in the adult. A thick glycocalyx covers the body of the metacercaria. Direct fluorescence revealed filamentous actin in the spines and the subtegumental musculature of the adult. The subtegumental musculature comprises two systems consisting of an outer circular layer and an inner layer composed of cross-linked longitudinal and diagonal fibres. Immunoreactivity in adults and metacercariae revealed the presence of actin in the spines and subtegumental musculature but not in the tegumental matrix, interstitial fibrous material nor the parenchyma. Actin was detected in the dense collar and bulb matrix of the tegumental ciliated sensilla and, for the first time, in the apical cytoplasmatic projections of the digestive cell of the adult.

Actins↗

The complete genomic sequence of a BLV strain from a Holstein cow from Argentina.

DNA was extracted from the peripheral blood of a seropositive, PCR-positive, BLV-infected Holstein cow (No. 38) from Argentina. The DNA was amplified via PCR with a series of overlapping primers encompassing the entire BLV proviral DNA. The amplified BLV ARG 38 DNA was cloned, sequenced, and compared phylogenetically to three other full-length BLV sequences. Characterization of its deduced proteins and its relationship to other members of the PTLV/BLV genus of retroviruses are discussed.

Amino Acid Sequence↗

Identification of novel trkA variants with deletions in leucine-rich motifs of the extracellular domain.

The peripheral expression of trkA encoding for NGF receptor was investigated by RNase protection assay. A thymus-specific protected fragment was identified. Using 5' rapid amplification of cDNA ends, three different trkA fragments were characterized. The longer fragment corresponded to the classical trkA L3 transcripts while the two shorter fragments lacked sequences encoding for leucine-rich motifs of the extracellular domain of TrkA, similarly to the trkB L1 and L0 variants. RT-PCR analysis of adult rat tissues showed the expression of trkA L1 transcripts in the thymus, testis, lung and kidney but not in the central nervous system. Their combined expression with trkA L3 transcripts suggests that specific peripheral TrkA oligomers may modulate NGF binding and function in non-neuronal cells.

Amino Acid Motifs↗

Molecular cloning and expression of novel sulphotransferase-like cDNAs from human and rat brain.

The sulphotransferase (SULT) gene family is involved with the conjugation of many small drugs, xenobiotics and endogenous compounds. In this report, we describe the cloning and expression of novel cDNAs from human and rat brain, which are structurally related to the SULTs. These cDNAs have been termed 'brain sulphotransferase-like' (BR-STL), because of their similarity to the SULTs and their selective expression in brain tissue. The proteins encoded by the human and rat BR-STL cDNAs (hBR-STL-1 and rBR-STL cDNA respectively), denoted as hBR-STL and rBR-STL, are 98% identical and 99% similar in sequence. The hBR-STL-1 cDNA contains an 852-nt open reading frame encoding a 284-amino-acid protein with a calculated molecular mass of 33083 Da. Northern-blot analyses of RNA isolated from eight human tissues indicate that the hBR-STL message is selectively expressed in brain. Characterization of different brain regions showed that message levels were highest in cortical brain regions. rBR-STL message levels were relatively low in brains of 1-day-old male and female rats, but increased to adult levels in RNA from 7-day-old rats, and remained at that level in adult animals. The hBR-STL and rBR-STL cDNAs were expressed in both Escherichia coli and Sf9 insect cells in the presence or absence of an N-terminal histidine-affinity tag (His-tag). Polyclonal antibodies were raised in chickens against purified His-tagged hBR-STL, and were used to detect the presence of rBR-STL in adult male and female rat brain cytosol. The high degree of sequence conservation, and the selective localization of the BR-STL message in brain, suggest an important function in the central nervous system.

Amino Acid Sequence↗