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Biomedical subjects

F Moreno

Publications and source records attributed to F Moreno.

At least 91 records · Page 5Linked to original sources
PubMed2000

Serum leptin and habitual fatty acid dietary intake in patients with type 1 diabetes mellitus.

OBJECTIVE: To study the contribution of a normal intake of nutrients to the variability of serum leptin concentrations in persons with type 1 diabetes mellitus. DESIGN: We studied the relation between serum leptin and nutrient intake in a cross-sectional study. METHODS: Serum leptin measured by radioimmunoassay, nutritional data determined by a self-administered 7-day nutritional questionnaire, and the fatty acid composition of the serum phospholipids (measured by thin layer chromatography and gas chromatography) were determined in 60 patients with type 1 diabetes mellitus. Correlation and regression analyses were performed between serum leptin and dietary fatty acids and serum phospholipid fatty acids. RESULTS: In the prediction models for the concentrations of serum leptin in men with type 1 diabetes mellitus, the dietary fatty acids displaced the anthropometric variables, and were independent of the serum testosterone concentrations. This fact remained when the prediction was made on the basis of indirect markers of the intake, such as the serum phospholipid fatty acids. In the women, the fatty acids from the diet or from the serum phospholipids also partly explained the variation in serum leptin, although not displacing the anthropometric variables. CONCLUSIONS: Our data suggest that, in non-experimental conditions, the concentrations of serum leptin in men with type 1 diabetes mellitus and, to a lesser extent, those in women with diabetes, may be influenced by the composition of the habitual diet, especially the type of dietary fat.

Adolescent↗
PubMed2000

Mirtazapine substitution in SSRI-induced sexual dysfunction.

BACKGROUND: Sexual side effects are a common and bothersome reaction to selective serotonin reuptake inhibitors (SSRIs), frequently leading to cessation of treatment. Mirtazapine, an alpha2-adrenoceptor and serotonin-2/3 receptor antagonist, appears to cause few sexual problems. METHOD: Nineteen patients (12 women and 7 men), with SSRI-induced sexual dysfunction who were in remission from major depressive disorder (total Hamilton Rating Scale for Depression [HAM-D] score < or = 10), were switched to open-label mirtazapine for up to 6 weeks. Mirtazapine was titrated from 7.5 mg to 45 mg daily, as tolerated. Sexual functioning was measured weekly with the Arizona Sexual Experiences Scale (ASEX), and depression was measured weekly with the HAM-D. RESULTS: Eleven patients (58%) had a return of normal sexual functioning (mean +/- SD ASEX score = 12+/-3), and another 2 (11%) reported significant improvement in sexual functioning (mean ASEX score reduced from 24+/-1 to 20+/-0). All nineteen patients maintained their antidepressant response (HAM-D score after 6 weeks of mirtazapine = 6+/-3). The most commonly reported side effects (using moderate/severe rating on a symptom checklist) were initial sedation (N = 3), irritability (N = 6), and muscle soreness and stiffness (N = 3). Weight gain of 10 to 20 lb (4.5-9 kg) was seen in 3 patients (2 women and 1 man). CONCLUSION: Mirtazapine is an effective antidepressant for many patients experiencing SSRI-induced sexual dysfunction.

Adrenergic alpha-Antagonists↗
PubMed2000

[Thyroid function alterations in children with congenital cardiac disease after catheterization with iodinated contrast agents].

INTRODUCTION AND OBJECTIVES: Iodinated contrast agents can block thyroid hormone synthesis. The aims of this study were: 1st) to study the incidence of thyroid function disturbances in children with congenital heart disease after cardiac catheterization, 2nd) to analyze the predisposing factors that may lead to the development of hypothyroidism after angiography, and 3rd) to determine the duration of these hypothyroidism states. PATIENTS AND METHODS: From february 1993 to April 1997 thyrotropine (TSH) and free thyroxine (FT4) serum values were analyzed before cardiac catheterization and in the two following weeks, in 99 children under three years of age, with congenital cardiac disease. Those patients who showed any postangiography increase in TSH were further evaluated by weekly measures of serum thyroid hormones and TSH until normal values were obtained or until the initiation of hormonal replacement therapy. The patients' data (age, previous exposure to contrast agents, cardiac disease, associated extracardiac malformations, renal failure, severity of illness, treatment) and the catheterism data (the dose and type of contrast and the fluoroscopy time) were included in the univariant analysis. RESULTS: 10 mUI/ml), that persisted beyond three weeks in six cases. The occurrence of multiple malformation syndromes was the most clearly associated risk factor (p < 0,01) not only in the development of postangiography hypothyroidism but also in longer hormonal dysfunction. CONCLUSIONS: Thyroid function should be tested in every patient with multiple malformation syndrome that undergo angiocardiography with iodinated contrast agents.

Cardiac Catheterization↗
PubMed1999

Analysis by atomic force microscopy of Med8 binding to cis-acting regulatory elements of the SUC2 and HXK2 genes of saccharomyces cerevisiae.

Med8 protein is a regulator that specifically binds to upstream activating sequences (UASs) of SUC2 promoter, to downstream repressing sequences (DRSs) of the HXK2 gene and to the carboxy-terminal domain of the RNA polymerase II. Atomic force microscopy has allowed for direct visualization of Med8 interactions with a 305 bp fragment of SUC2 promoter and with a 676 bp fragment of HXK2 gene, containing respectively the UASs and DRSs regulatory regions. This approach has provided complementary information about the position and the structure of the DNA-protein complexes. Med8 binding to DNA results in total covering of one of the two existing 7 bp motives (consensus, (A/C)(A/G)GAAAT) in the studied DNA fragments. No preference for binding either of the two UASs of SUC2 promoter as well as for the two DRSs of HXK2 gene has been found. We also discuss whether this protein works as dimer or as a monomer.

Carrier Proteins↗
PubMed1999

Functional characterization of transcriptional regulatory elements in the upstream region of the yeast GLK1 gene.

The glucokinase gene GLK1 of the yeast Saccharomyces cerevisiae is transcriptionally regulated in response to the carbon source of the growth medium. Northern-blot analysis shows that the GLK1 gene is expressed at a basal level in the presence of glucose, de-repressed more than 6-fold under conditions of sugar limitation and more than 25-fold under conditions of ethanol induction. lacZ fusions of the GLK1 gene promoter were constructed and a deletion analysis was performed in order to identify the cis-acting regulatory elements of the promoter that controls GLK1 gene expression. First, the expression seemed to be mediated mainly by one GCR1 and three stress-responsive element (STRE) activating elements. Secondly, an ethanol repression autoregulation (ERA)/twelve-fold TA repeat (TAB) repressor element was identified within the promoter region of the GLK1 gene. A specific and differential protein binding to the STRE was observed with extracts from de-repressed and repressed cells. No differential binding to the GCR1 or ERA/TAB elements was observed with extracts from de-repressed and repressed cells, but, in both cases, the binding was competed for by an excess of the unlabelled GLK1(GCR1) and GLK1(ERA) sequence. The transcription factors Msn2 and Msn4, which bind to the GLK1 upstream region through the STRE, contribute to inductive activation. The transcription factor Gcr1, which binds through the GCR1 element, contributes to constitutive activation. In order to achieve the severe glucose repression of GLK1, constitutive repressor factors acting through the ERA/TAB element must counteract constitutive activation generated by Gcr1 binding to the GCR1 element. Full expression of the GLK1 gene is produced by inductive activation of three STRE when Msn2 and Msn4 proteins are translocated to the nucleus by covalent modification. The combinatorial effect of the entire region leads to the regulated transcription of GLK1, i.e., silent in media with glucose and other preferred carbon sources, such as fructose or mannose, and increased levels of expression upon glucose depletion.

Base Sequence↗
PubMed1999

Binding of the Promen fluorescent probe to human serum albumin: a fluorescence spectroscopic study.

The binding of Promen (6-propionyl-2-methoxynapthalene) to human serum albumin (HSA) was measured by fluorescence spectroscopy, finding only one class of binding sites on the protein. Hydrophobic interactions play an important role to stabilize the complex. Attempts were made to characterize its binding site using as competitors warfarin, phenylbutazone and diazepam, which bind in a specific site or region on the HSA. Fluorescence polarization measurements and spectrofluorimetric results suggest that diazepam and Promen bind at different but interacting binding sites on the HSA. The changes in the fluorescence emission of the bound Promen in the presence of these drugs, allow to use Promen to detect unspecific interactions with the site II on the HSA.

Binding Sites↗
PubMed1999

Med8, a subunit of the mediator CTD complex of RNA polymerase II, directly binds to regulatory elements of SUC2 and HXK2 genes.

In a search to identify new factors required for expression of SUC2 gene in Saccharomyces cerevisiae, we have partially purified a 27 kDa protein (p27) that bound both the DRSs of the HXK2 gene and the UASs of SUC2 gene. The amino terminal sequence of p27 identified the MED8 gene (open reading frame YBR193C), located in chromosome II of S. cerevisiae, as the gene coding for the protein. Disruption of this gene has demonstrated that is an essential gene for yeast growth. To determine whether the p27 protein represents the Med8 product, we expressed MED8 gene in E. coli and demonstrated that the heterologous synthesized protein specifically binds to both UASSUC2 and DRS2HXK2. This observation suggests that Med8 may be important for the coupling of the glucose repression pathway of SUC2 gene to the HXK2 gene expression. Med8 has been described as a mediator protein interacting with the CTD of the RNA polymerase II. Thus, the role of Med8 could be to act as coupling factor by linking activating and repressing transcription complexes to the RNA polymerase II holoenzyme transcriptional machinery.

Chromosome Mapping↗
PubMed1999

The cyclic structure of microcin J25, a 21-residue peptide antibiotic from Escherichia coli.

Microcin J25 (MccJ25) is the single representative of the immunity group J of the microcin group of peptide antibiotics produced by Enterobacteriaceae. It induces bacterial filamentation in susceptible cells in a non-SOS-dependent pathway [R. A. Salomon and R. Farias (1992) J. Bacteriol. 174, 7428-7435]. MccJ25 was purified to homogeneity from the growth medium of a microcin-overproducing Escherichia coli strain by reverse-phase HPLC. Based on amino acid composition and absolute configuration determination, liquid secondary ion and electrospray mass spectrometry, extensive two-dimensional NMR, enzymatic and chemical degradations studies, the structure of MccJ25 was elucidated as a 21-residue peptide, cyclo(-Val1-Gly-Ile-Gly-Thr- Pro-Ile-Ser-Phe-Tyr-Gly-Gly-Gly-Ala-Gly-His-Val-Pro-Glu-Tyr-Phe21- ). Although MccJ25 showed high resistance to most of endoproteases, linearization by thermolysin occurred from cleavage at the Phe21-Val1 bond and led to a single peptide, MccJ25-L. While MccJ25 exhibited remarkable antibiotic activity towards Salmonella newport and several E. coli strains (minimal inhibitory concentrations ranging between 0.01 and 0.2 microgram.mL-1), the thermolysin-linearized microcin showed a dramatic decrease of the activity, indicating that the cyclic structure is essential for the MccJ25 biological properties. As MccJ25 is ribosomally synthesized as a larger peptide precursor endowed with an N-terminal extremity, the present study shows that removal of this extension and head-tail cyclization of the resulting propeptide are the only post-translational modifications involved in the maturation of MccJ25, that appears as the first cyclic microcin.

Amino Acid Sequence↗
PubMed1999

Red muscle development of gilthead sea bream Sparus aurata (L.): structural and ultrastructural morphometry.

The transverse red and white muscle area, the superficial red muscle fibres area and their percentages of mitochondria (%mit), myofibrils (%myof) and sarcoplasm (%sarc) were determined in the Mediterranean teleost gilthead sea bream, Sparus aurata (L.). Fish aged from hatching to 78 days were studied. The proportional growth of the red and white muscles was higher for the red muscle in the first half of the larval stage (1-35 days). Then the opposite relationship was observed. The hypertrophic growth of the superficial muscle fibres was continuous except in the first week after hatching. The percentage of mitochondria and percentage of myofibrils showed a significant change just after the half of the larval stage. Whereas the %mit of the superficial muscle fibres was higher than %myof from the first week after hatching to 35 days (average 66.64%), then the %mit decreased significantly and at 73-78 days both parameters were close to an average value of 50%. The meaning of these morphological changes is discussed in relation to the functional role of the red muscle of larvae and the onset of the gills respiration.

Aging↗
PubMed1999

The A1555G mutation in the 12S rRNA gene of human mtDNA: recurrent origins and founder events in families affected by sensorineural deafness.

The mtDNA variation of 50 Spanish and 4 Cuban families affected by nonsyndromic sensorineural deafness due to the A1555G mutation in the 12S rRNA gene was studied by high-resolution RFLP analysis and sequencing of the control region. Phylogenetic analyses of haplotypes and detailed survey of population controls revealed that the A1555G mutation can be attributed to >/=30 independent mutational events among the 50 Spanish families and that it occurs on mtDNA haplogroups that are common in all European populations. This indicates that the relatively high detection rate of this mutation in Spain is not due to sampling biases or to a single major founder event. Moreover, the distribution of these mutational events on different haplogroups is compatible with a random occurrence of the A1555G mutation and tends to support the conclusion that mtDNA backgrounds do not play a significant role in the expression of the mutation. Overall, these findings appear to indicate that the rare detection of this mutation in other populations is most likely due to inadequacy in patient ascertainment and molecular screening. This probable lack of identification of the A1555G mutation in subjects affected by sensorineural hearing loss implies that their maternally related relatives are not benefiting from presymptomatic detection and information concerning their increased risk of ototoxicity due to aminoglycoside treatments.

DNA Mutational Analysis↗
PubMed1999

Antidepressants and the brain.

The pathophysiology and effects of antidepressants in the brain are still poorly understood. While it is generally accepted that increasing the levels of monoamine in the brain is an effective way to alleviate depression, the precise neurobiological mechanisms are unclear. The evidence that monoamine function is impaired in individuals with depression is largely indirect. However, the neurotransmitter depletion model allows a more direct investigation of the role of the monoamines. In this model, tryptophan depletion is used to lower levels of serotonin and alpha-methylparatyrosine is used to induce catecholamine depletion in the brain. Studies have shown that such depletion transiently reverses antidepressant responses in the majority of patients, the response being dependent on the type of antidepressant used. However, depletion in unmedicated patients with depression did not worsen the depressive symptoms, neither did it cause depression in healthy subjects with no history of mental illness. The cause(s) of depression therefore appears to be more complex than simply a reduction in levels of monoamine or diminished function in these systems. The pathophysiology of depression may relate to dysfunction in brain areas modulated by monoamine systems. Antidepressant drugs may mediate their effects by causing adaptive changes in neurones localised in these brain areas.

Animals↗
PubMed1999

Sequence analysis of the four plasmid genes required to produce the circular peptide antibiotic microcin J25.

A 4.8-kb plasmid region carrying the four genes mcjABCD necessary for production of and immunity to the cyclic peptide antibiotic microcin J25 (MccJ25) has been sequenced. mcjA encodes the primary structure of MccJ25 as a precursor endowed with an N-terminal extension of 37 amino acids. The products of mcjB and mcjC are thought to be involved in microcin maturation, which implies cleavage of McjA and head-tail linkage of the 21-residue pro-MccJ25. The predicted McjD polypeptide, which is highly similar to several ABC exporters, was found to be required for MccJ25 secretion, thus explaining its ability to confer immunity to MccJ25.

ATP-Binding Cassette Transporters↗
PubMed1999

The fluorescent probe prodan characterizes the warfarin binding site on human serum albumin.

The fluorescent probe Prodan (6-propionyl-2-dimethyl-aminonaphthalene) binds with high affinity to human serum albumin (HSA). The spectral characteristics of the Prodan bound to the protein are very different from the free Prodan in solution. These differences allowed the spectra to be deconvoluted into log-normal bands in order to quantify the bound and unbound ligand and to calculate the binding constant at different temperatures. From such temperature dependence, we found the binding to be exothermic with a van't Hoff enthalpy of -22.8 kJ mol-1. Thermodynamic analysis suggests that the interaction may be mainly caused by hydrophobic forces and electrostatic interactions. The above analysis of the spectra and the measures of the fluorescence polarization during the successive presence of six specific drugs suggest that the Prodan binding site corresponds with the warfarin binding site on HSA, whereas under the present experimental conditions the other characteristic binding sites of HSA were not affected. Thus, this fluorescent probe provides a rapid and simple means for the characterization of a specific binding site on HSA and also for detecting potential or nonspecific drug-protein interactions.

2-Naphthylamine↗
PubMed1999

[Non-syndromic familial hearing impairment transmitted by mitochondrial inheritance].

OBJECTIVE: To determine the clinical features and mode of inheritance of hearing impairment observed in several members of a Spanish family with putative genetic susceptibility to ototoxicity induced by aminoglycoside antibiotics. MATERIALS AND METHODS: In 14 patients belonging to the same family, an interview, otological examination and audiometry were carried out. Three of these patients also underwent a study of brainstem auditory-evoked potentials. A genetic study was made of 11 patients and 9 unaffected relatives to determine the mode of inheritance of the hearing impairment and to detect associated mutations. RESULTS: Most of the patients developed hearing loss before the age of 8 years, particularly for high frequencies. In almost all of them, there was no further evolution. Six patients had previous exposure to ototoxic drugs. Three patients had sudden hearing loss. In 2 of the 3 patients examined for brainstem auditory-evoked potentials, the hearing impairment was of cochlear origin. The genetic study detected A1555G mutation in the mitochondrial DNA of all the maternal relatives studied. CONCLUSIONS: Mitochondrially-inherited sensorineural hearing loss should be suspected in families with a maternal transmission of the disorder and more than one relative with aminoglycoside-induced hearing loss.

Acoustic Impedance Tests↗
PubMed1999

Paternity analysis when the putative father is missing: first case in Chile.

Genetic marker analysis is a powerful tool for solving paternity-related problems when the putative father is missing. This report describes the first time this approach was employed in Chile to solve such a problem. In the case presented, the alleged father was missing as a result of the political detentions that took place in Chile during 1973. It was not possible to obtain any biological sample from him because he was missing. Thus, the case was resolved by means of genetic marker analysis of the alleged father's close relatives.

Birth Certificates↗
PubMed1999

[Sweet syndrome associated with articular and renal involvement].

We report a 29 years old female presenting with fever and painful infiltrated erythematous and violaceous plates with pseudo vesicles in the surface, located in both arms, four days after having suffered a tonsillitis. She was admitted with the diagnosis of Sweet syndrome and the lesions disappeared spontaneously. Two months later, she presented with a similar condition, again after an upper respiratory infection. Five months later, she was admitted with arthralgias with positive rheumatoid factor and antinuclear antibodies. Three years after the first admission, she was admitted with an acute glomerulonephritis and renal failure after another upper respiratory infection. Sweet syndrome was described in 1964 and, although initially considered benign, its association with inflammatory diseases or cancer has been reported.

Adult↗