Search PubMed⌕ Search

Biomedical subjects

M Gil

Publications and source records attributed to M Gil.

At least 37 records · Page 2Linked to original sources
PubMed2001

Vibrations of the phenoxyl radical.

Phenoxyl radical (C(6)H(5)O) was prepared photochemically in low-temperature argon matrices. The infrared absorption spectra were obtained for C(6)H(5)O and for the isotopically labeled species C(6)D(5)O and 1-(13)C(12)C(5)H(5)O. All but one IR-active fundamental vibrations were detected, most of them not previously observed. Combination of results from IR linear dichroism measurements on photooriented samples, determination of absolute IR intensities with the help of internal standards, analysis of isotopic shifts, and quantum chemical predictions (B3LYP/cc-pVTZ) led to a detailed assignment of phenoxyl radical vibrations. Significant frequency shifts are observed with respect to previously reported data based on resonance Raman studies in polar solutions. For some vibrations, these shifts reflect environment-induced structural changes, such as increase of the quinoid character of the phenoxyl radical in polar media. In particular, the frequency of the CO stretching vibration, readily observable in both IR and Raman experiments, is extremely sensitive to the environment and can thus be used to probe its polarity.

Free Radicals↗
PubMed2001

New cytotoxic benzo(b)thiophenilsulfonamide 1,1-dioxide derivatives inhibit a NADH oxidase located in plasma membranes of tumour cells.

A series of benzo(b)thiophenesulfonamide 1,1-dioxide derivatives (BTS) have been designed and synthesized as candidate antineoplastic drugs. Several of these compounds have shown in vitro cytotoxic activity on leukaemic CCRF-CEM cells. The cytotoxic BTS, but not the inactive ones, were able to inhibit a tumour cell-specific NADH oxidase activity present in the membrane of CCRF-CEM cells.

Antineoplastic Agents↗
PubMed2001

Ability of a Au(III)-N unit to bond two aurophilically interacting gold(I) centers.

The monohapto neutral 2-(diphenylphosphino)aniline (PNH(2)) complexes [Au(C(6)F(5))(2)X(PNH(2))] (X = C(6)F(5) (1), Cl (2)) have been obtained from [Au(C(6)F(5))(3)(tht)] or [Au(C(6)F(5))(2)(micro-Cl)](2) and PNH(2), and the cationic [Au(C(6)F(5))(2)(PNH(2))]ClO(4) (3) has been similarly prepared from [Au(C(6)F(5))(2)(OEt(2))(2)]ClO(4) and PNH(2) or from 2 and AgClO(4). The neutral amido complex [Au(C(6)F(5))(2)(PNH)] (4) can be obtained by deprotonation of 3 with PPN(acac) (acac = acetylacetonate) or by treatment of the chloro complex 2 with Tl(acac). It reacts with [Ag(OClO(3))(PPh(3))] or [Au(OClO(3))(PPh(3))] to give the dinuclear species [Au(C(6)F(5))(2)[PNH(MPPh(3))]]ClO(4) (M = Ag (5), Au (6)). The latter can also be obtained by reaction of equimolar amounts of 3 and [Au(acac)(PPh(3))]; when the molar ratio of the same reagents is 1:2, the trinuclear cationic complex [Au(C(6)F(5))(2)[PN(AuPPh(3))(2)]]ClO(4) (7) is obtained. The crystal structures of complexes 2-4 and 7 have been established by X-ray crystallography; the last-mentioned displays an unusual Au(I)-Au(III) interaction.

Journal Article↗
PubMed2001

FTIR study of five complex beta-lactam molecules.

Five monocyclic 4-benzoyl-4-phenyl-beta-lactam derivatives in carbon tetrachloride solutions were studied by FTIR spectroscopy. The Fourier self-deconvolution method was applied to enhance the resolution of the FTIR spectra. The calculated spectra of these five compounds, which were obtained by quantum mechanical methods, were compared with FTIR data. A complete assignment of the vibrational frequencies in the 4000-400 cm(-1) range was made. Several vibrations were selected as being useful to characterize the beta-lactam ring. Substituents on N1 (p-methoxyphenyl) and C3 (methyl, phenyl, maleimidyl, and phthalimidyl) on the beta-lactam ring increase the amide resonance and the planarity of the ring. The optimized geometry along with the total electric charges on the four atoms of the ring support an antibiotic action mechanism by a nucleophilic attack of the enzymes on the carbonyl carbon atom of the beta-lactam ring.

Anti-Bacterial Agents↗
PubMed2001

Self-consciousness and Alzheimer's disease.

OBJECTIVES: To propose a neuropsychological study of the various aspects of self-consciousness (SC) in Alzheimer's disease. METHODS: Forty-five patients with probable mild or moderate AD were included in the study. Severity of their dementia was assessed by the Mini Mental State (MMS). Fourteen questions were prepared to evaluate SC. RESULTS: No significant correlations were found between SC score and educational level, age, and duration of disease. A significant correlation was found between SC score and the severity of dementia, whereas frontal disturbances were just short of the significance threshold. The various aspects of SC were not impaired to the same degree. The most disturbed ones were awareness of cognitive deficiencies, moral judgements and prospective memory. The least disturbed aspects were awareness of identity and of mental representation of the body. Items relating to anosognosia and moral judgements were significantly correlated with the MMS score, whereas affective state, body representation disorders, prospective memory, and capacities for introspection were not related to the severity of the dementia. Consciousness of identity was sound, regardless of MMS score. CONCLUSIONS: AD clearly induces an heterogeneous impairment of SC. SC requires a convergence of many neural networks. In AD, neuronal alterations involve many cortical areas and information sent to the associative frontal cortex from memory, language and visuospatial areas is lacking or disturbed. Thus, the sequential order of successive stimuli cannot be maintained by the heteromodal associative cortex (dorsal convexity of the prefrontal cortex), and the supramodal associative cortex (located rostrally in the frontal lobes) is unable to provide reliable monitoring and assessment of simultaneous neural cognitive networks carrying insufficient and inadequate input. The core deficiency in AD patients might be impaired SC equated with the disability to maintain sequential and simultaneous "attention to life". The Self-Consciousness Questionnaire, a clinical scale providing multidimensional measurement, indicates that different aspects of consciousness are not correlated with overall cognitive deficiency as determined by the MMSE.

Aged↗
PubMed2001

Purification and conformational properties of a human interferon alpha2b produced in Escherichia coli.

Recombinant human interferon alpha2b was expressed intracellularly in Escherichia coli as insoluble aggregates using a new expression vector, and was purified to homogeneity using essentially two-step chromatographic procedures, i.e. immobilized metal-ion-affinity chromatography and reversed-phase HPLC. The established purification process is highly reproducible and leads to a total recovery of approx. 12% with a specific biological activity of higher than 1x10(8) i.u./mg of protein, which is comparable with the international requirement for interferon alpha2b. For purified protein we report conformational stability as a function of pH and temperature using differential scanning calorimetry and CD. Thermal unfolding as a function of pH showed only one endotherm at a temperature higher than 45 degrees C, and was reversible at pH 2-3.75 and irreversible at pH 4-10. At pH 7.0, the most stable condition, the conformational stability depends on protein concentration and ionic strength. The highly helical secondary structure is very conserved over the whole pH range studied, including at high temperatures.

Calorimetry, Differential Scanning↗
PubMed2001

An unusual subcellular localization of GLUT1 and link with metabolism in oocytes and preimplantation mouse embryos.

Although mouse oocytes and cleavage-stage embryos prefer pyruvate and lactate for metabolic fuels, they do take up and metabolize glucose. Indeed, presentation of glucose during the cleavage stages is required for subsequent blastocyst formation, which normally relies on uptake and metabolism of large amounts of glucose. Expression of the facilitative glucose transporter GLUT1 was examined using immunohistochemistry and Western blotting, and in polyspermic oocytes, metabolism of glucose was measured and compared with that of pyruvate and glutamine. GLUT1 was observed in all oocytes and embryos, and membrane and vesicular staining was present. Additionally, however, in polyspermic oocytes, the most intense staining was in the pronuclei, and this nuclear staining persisted in cleaving normal embryos. Furthermore, GLUT1 expression appeared to be up-regulated both in nuclei and plasma membranes following culture of oocytes in the absence of glucose. In polyspermic oocytes, the metabolism of glucose, but not of pyruvate or glutamine, was directly proportional to the number of pronuclei formed. After compaction, nuclear staining diminished, and GLUT1 localized to basolateral membranes of the outer cells and trophectoderm. In blastocysts, a weak but uniform staining of inner-cell-mass plasma membranes was apparent. The results are discussed in terms of potential roles for GLUT1 in pronuclei of oocytes and zygotes, nuclei of cleavage-stage embryos, and a transepithelial transport function for GLUT1, probably coupled with GLUT3, in compacted embryos and blastocysts.

Animals↗
PubMed2001

Role of age and sex in short-term and long term mortality after a first Q wave myocardial infarction.

STUDY OBJECTIVE: The objective of this study was to analyse whether the risk of death within 28 days and three years after a first Q wave myocardial infarction was higher in hospitalised women than in men. DESIGN: Follow up study. PATIENTS AND SETTING: All consecutive first Q wave myocardial infarction patients aged 25 to 74 years (447 women and 2322 men) admitted to a tertiary hospital in Gerona, Spain, from 1978 to 1997 were registered and followed up for three years. MAIN RESULTS: Women were older, presented more comorbidity and developed more severe myocardial infarctions than men. A significant interaction was found between sex and age. Women aged 65-74 had higher early mortality risk than men of the same age (OR 1.62; 95% CI 1.01, 2.66) after adjusting for age, comorbidity and acute complications including heart failure. Women under 65 tended to be at lower risk of early mortality than men (0.45 (95% CI 0.19, 1.04). Three year mortality of 28 day survivors did not differ between sexes. CONCLUSIONS: These data support the idea that the higher 28 day mortality in hospitalised women with a first Q wave myocardial infarction is mainly attributable to the large number of patients aged 65 to 74 years in whom the risk is higher than that in men. Women under 65 with myocardial infarction do not seem to be a special group of risk.

Adult↗
PubMed2000

[Comparison of primary care teams in Barcelona according to management formulas].

OBJECTIVE: The aim of the study is to compare, among socio-economically similar areas, the use of medical services, clinical practice and pharmacy costs depending on the how the primary healthcare teams, that provide these services, are organized according to different managemental formulas. DESIGN: Descriptive study of the evaluation of health care services. PATIENTS AND METHODS: The population units (basic health areas) attended by the reformed primary health care services in Barcelona were classified into three levels according to the population's socioeconomic status (high, medium or low). For each level, two primary health care teams were selected representing different primary health care providers: "Institut Catala de la Salut"; and others. The influence of both the provision option and the population characteristics on service use, clinical practice and costs of prescription were compared. MAIN RESULTS: The services offered by the two provision options differ. However, the use of medical services is related to the socioeconomic characteristics and not to the option for service provision. Whilst there are no relevant differences in clinical practice between the different options, we observed variations among different primary care teams, notably in referrals to specialists and influenza vaccine coverage. The greater source of variation in prescription costs seems to be related to an external confounding factor. CONCLUSIONS: Empirical data have not identified relevant differences in the pattern of use, clinical practice, or costs between the different options for service provision within the model of reformed primary care services. Observed variations seem to be associated mainly with the population's characteristics, its pattern of health service use or other external confounding factors.

Clinical Laboratory Techniques↗
PubMed2000

Keratin 9 is a component of the perinuclear ring of the manchette of rat spermatids.

Previous work in our laboratory has shown that a 62- to 64-kDa protein was a major component of the perinuclear ring of manchettes fractionated from rat spermatids. Mass spectrometry analysis of this protein indicated the presence of a glycine-rich domain homologous to human keratin 9 (K9). Several antibodies to K9, raised against synthetic peptides of human K9, recognized the 64- to 62-kDa protein in the perinuclear ring of the manchette as well as in keratinocytes of the suprabasal layer of the rat and human footpad/sole epidermis in both immunoblotting and immunocytochemical experiments. Based on these data, human-derived K9 primers were used to clone rat K9 cDNA from epidermis by RT-PCR. Rat-specific K9 primers were then used to perform a two-step (nested) PCR to amplify the K9-specific rat testicular RNA and to obtain cDNA to demonstrate K9 gene expression in rat testis. The deduced amino acid sequence of rat K9 cDNA contains 618 amino acids with an estimated molecular mass of 63,020 Da, in agreement with that obtained by electrophoretic fractionation of rat manchette and epidermis footpad proteins. The deduced protein structure correlates with the recognizable pattern of keratins: a rod domain of 304 amino acids with well-conserved initiation and termination sequences (MQNLNSRLASY and EIETYRKLLEG, respectively), flanked by glycine/serine-rich head and tail domains of 141 and 173 amino acids, respectively. A high content of phenylalanine was detected in the head domain and a repetitive motif (SGGSYGGGS) in the tail domain. A comparison with human keratin 9 showed an overall nucleotide and amino acid similarity of 75%. An increased level of K9 transcripts was detected in a cDNA library prepared from fractionated round spermatids. Results of this study show that rat testis expresses K9 and that this protein is a component the perinuclear ring of the manchette of rat spermatids.

Amino Acid Sequence↗
PubMed2000

Monitoring of biologically effective UV irradiance at El Arenosillo (INTA), Andalucia, in Spain.

Biological UV (ultraviolet) dosimetry was applied using the biofilm-technique (DLR patent) to determine the UV levels weighted of biologically weighted UV radiation at the INTA Sounding Station of El Arenosillo at Huelva, Spain (37 degrees 06'N, 6 degrees 44'W, 50 m a s 1=above sea level) on 2 days in 1997 [correction of 1977] (April 1, and May 5). Exposure periods were calculated for clear sky days using a radiative transfer model for erythemal doses to reach 1.3 to 1.5 MED (minimal erythemal dose). Reliability of the radiative transfer model was demonstrated by the doses registered by a Yankee-UV biometer for the same exposure periods as used for the biosensor. This work presents the methodology employed (biofilm-technique utilized [correction of utiliced], calculation of exposing periods with radiative transfer model, etc) and the results obtained with the Yankee biometer and the biofilm. At noon, the ratio of biofilm measurements (Ieff, W/m2=biological effective irradiance, in W/m2) to the UV Biometer data (in MED/h) was 3-4.

Bacillus subtilis↗
PubMed2000

Degradation of o-methoxybenzoate by a two-member consortium made up of a gram-positive Arthrobacter strain and a gram-negative Pantotea strain.

Aromatic carboxylic acids substituted with methoxylated groups are among the most abundant products in "alpechin", the wastes resulting from pressing olives to obtain olive oil. Degradation of o-methoxybenzoate by an stable consortium made of a gram positive bacterium, Arthrobacter oxydans, and gram negative one, Pantotea agglomerans, was shown to mineralize this compound efficiently. The concerted action of both microorganisms was needed for the two first steps in the process, namely, the conversion of o-methoxybenzoate into salycilate, and the hydroxylation of the latter to gentisate. Gentisate was further degraded by the Arthrobacter strain.

Anisoles↗
PubMed2000

Pharmacologic suppression of target cell recognition by engineered T cells expressing chimeric T-cell receptors.

Adoptive therapy with autologous T cells expressing chimeric T-cell receptors (chTCRs) is of potential interest for the treatment of malignancy. To limit possible T-cell-mediated damage to normal tissues that weakly express the targeted tumor antigen (Ag), we have tested a strategy for the suppression of target cell recognition by engineered T cells. Jurkat T cells were transduced with an anti-hapten chTCR tinder the control of a tetracycline-suppressible promoter and were shown to respond to Ag-positive (hapten-coated) but not to Ag-negative target cells. The engineered T cells were then reacted with hapten-coated target cells at different effector to target cell ratios before and after exposure to tetracycline. When the engineered T cells were treated with tetracycline, expression of the chTCR was greatly decreased and recognition of the hapten-coated target cells was completely suppressed. Tetracycline-mediated suppression of target cell recognition by engineered T cells may be a useful strategy to limit the toxicity of the approach to cancer gene therapy.

Flow Cytometry↗
PubMed2000

[Fibrinogen serum levels in patients with stable coronary artery disease and acute coronary syndrome].

Increased plasma fibrinogen level is an important prognostic factor of recurrent unstable angina and myocardial infarction in patients with acute coronary syndrome (ACS). The aim of our study was to assess the plasma fibrinogen level at baseline condition in patients admitted to hospital due to coronary artery disease (CAD). Plasma fibrinogen was measured in 51 consecutive patients presenting with ACS within the last 24 hours and in 50 patients with angiographically proven CAD that was stable for the past 30 days. For statistical analysis Mann-Whitney U test, Student t-test, chi-square test and Pearson correlation was used, p < 0.05 being considered statistically significant. There was significant correlation between fibrinogen level and diagnosis of ACS or CAD (r = 0.29, p = 0.002). In our population plasma fibrinogen levels (g/L +/- SD) were significantly different in patients with ACS when compared to CAD subjects (3.87 +/- 1.2 vs. 3.26 +/- 0.65, p = 0.002). There was difference between ACS and CAD subjects in male:female ratio (40/11 vs. 47/4, p < 0.001) and age (63.4 +/- 10.1 vs. 58.4 +/- 10.0, p = 0.014). Our results confirm the role of fibrinogen in pathogenesis of CAD. In our opinion plasma fibrinogen level may be an important diagnostic tool in assessment of patients with chest pain.

Aged↗
PubMed2000

[Prevalence of hereditary hemochromatosis among healthy workers. Diagnostic value of transferrin saturation assay].

AIM: Hereditary hemochromatosis is the most common inherited disorder in white population (2-8 cases per 1000 habitants). Hemochromatosis is characterized by increased intestinal absorption of iron leading to its deposition into multiple organs. An early diagnosis and proper management with frequent phlebotomies are known to improve life expectancy and quality of life. Diagnosis is suggested by an elevated Transferrin saturation (TS) (more than 60%). METHOD: Prospective study of the level of TS among 1131 healthy workers, who came to the Security and Hygiene Official Centre for their annual revision had been undertaken. RESULTS: Twenty-wo workers had high TS; in 10 of them the increase of TS was confirmed on repeated determinations. Liver biopsy was performed in six (and refused by the other four), eventually a diagnosis of hemochromatosis was confirmed in three (in-group prevalence of 2.6 per 1000 people). CONCLUSIONS: In our experience, TS is the most appropriate initial screening test for detecting hereditary hemochromatosis in a normal population.

Adult↗
PubMed1999

[An evaluation of the impact of primary care reform on health].

OBJECTIVE: Evaluation of the impact of the reform of primary health care services on the population health. DESIGN: Comparative analysis of mortality rates for the 1984-96 period in three zones of homogeneous socioeconomic level, assessing the effect of the differential development of the reform of public primary health care services. SETTING: The study is restricted to the 23 health areas with lower socioeconomic status in the city of Barcelona (443092 inhabitants). MEASUREMENTS AND MAIN RESULTS: The study areas are categorized in three groups, according to the sequence of the reform: reformed between 1984 and 1989, RAP1 zone, reformed between 1990 and 1991, RAP2 zone, and those still served by the old scheme in 1992, NORAP zone. General mortality rates are analyzed, and also mortality rates by those avoidable conditions. Significant differences among the three zones are initially visible. The mortality decline is 13.6% in the RAP1 zone and 10.3% in the NORAP zone, so that the decline in the RAP1 zone is 32% greater than in the NORAP zone. At the end of the study, mortality due to stroke and hypertension is lower in the RAP zones than in the NORAP zone. Perinatal mortality shows a clear decline in the three zones. No relevant changes are seen for tuberculosis or cervical cancer. Lung cancer mortality increases except in RAP1 zone where it declines, to the point that the excess mortality from that cause estimated by comparison with the NORAP zone in the initial phase of the study vanishes. Death rates from cirrhosis and motor vehicle accident decline in all zones. CONCLUSIONS: There is a clear association between the process of reform of primary care and the decrease in general mortality in these zones of low socioeconomic level. These results suggest that the reform of primary health care services in Spain may have a significant impact in the mortality of the population of lower socioeconomic level. The study highlight the cost in health and human lives of maintaining obsolete and overburdened services for some segments of the population, and justify the need and urgency of completing the process of reform initiated in 1984 and still unfinished in 1999.

Cause of Death↗