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1.
BJOG ; 128(11): 1855-1868, 2021 10.
Article in English | MEDLINE | ID: mdl-34218508

ABSTRACT

OBJECTIVE: To develop a core outcome set (COS) for randomised controlled trials (RCTs) evaluating the effectiveness of interventions for the treatment of pregnant women with pregestational diabetes mellitus (PGDM). DESIGN: A consensus developmental study. SETTING: International. POPULATION: Two hundred and five stakeholders completed the first round. METHODS: The study consisted of three components. (1) A systematic review of the literature to produce a list of outcomes reported in RCTs assessing the effectiveness of interventions for the treatment of pregnant women with PGDM. (2) A three-round, online eDelphi survey to prioritise these outcomes by international stakeholders (including healthcare professionals, researchers and women with PGDM). (3) A consensus meeting where stakeholders from each group decided on the final COS. MAIN OUTCOME MEASURES: All outcomes were extracted from the literature. RESULTS: We extracted 131 unique outcomes from 67 records meeting the full inclusion criteria. Of the 205 stakeholders who completed the first round, 174/205 (85%) and 165/174 (95%) completed rounds 2 and 3, respectively. Participants at the subsequent consensus meeting chose 19 outcomes for inclusion into the COS: trimester-specific haemoglobin A1c, maternal weight gain during pregnancy, severe maternal hypoglycaemia, diabetic ketoacidosis, miscarriage, pregnancy-induced hypertension, pre-eclampsia, maternal death, birthweight, large for gestational age, small for gestational age, gestational age at birth, preterm birth, mode of birth, shoulder dystocia, neonatal hypoglycaemia, congenital malformations, stillbirth and neonatal death. CONCLUSIONS: This COS will enable better comparison between RCTs to produce robust evidence synthesis, improve trial reporting and optimise research efficiency in studies assessing treatment of pregnant women with PGDM. TWEETABLE ABSTRACT: 165 key stakeholders have developed #Treatment #CoreOutcomes in pregnant women with #diabetes existing before pregnancy.


Subject(s)
Diabetes, Gestational/therapy , Outcome Assessment, Health Care/standards , Prenatal Care/standards , Consensus , Delphi Technique , Female , Humans , International Cooperation , Pregnancy , Randomized Controlled Trials as Topic , Stakeholder Participation , Treatment Outcome
2.
J Mol Model ; 25(11): 326, 2019 Oct 26.
Article in English | MEDLINE | ID: mdl-31655912

ABSTRACT

In recent years, the popularity of metal hydrides has increased considerably for hydrogen storage and their applications in hydrogen fuel cells. Their potential applications for clean energy are promissory. However, the temperatures required for adsorption and desorption are extremely high, which range between 500 and 700 K, making their use impractical. To overcome these difficulties, the following work considers using three hydride alloys: magnesium-aluminum (MgAl), magnesium-nickel (MgNi), and magnesium-zinc (MgZn). The Mg concentrations were set to be between 80 and 100 wt% in order to reduce the temperatures of adsorption and desorption in contrast with the temperatures of pure magnesium. The chemisorption and repulsion energies of the hydrogen molecule on the surface (110) of the different metallic alloys were studied at 0, 200, 400, 600, and 700 K, respectively. The study was based on the density functional theory (DFT), with the module DMol3 of the molecular simulation program Materials Studio, which was used to obtain these energy values. The results confirm that adding aluminum, nickel, or zinc into magnesium matrix increases the chemisorption and decreases the energy repulsion values on surfaces of the metallic alloys, improving the effectiveness of the hydrogen storage.

3.
Phys Chem Chem Phys ; 17(5): 3749-60, 2015 Feb 07.
Article in English | MEDLINE | ID: mdl-25557948

ABSTRACT

We describe the synthesis, crystal structure and lithium deinsertion-insertion electrochemistry of two new lithium-rich layered oxides, Li3MRuO5 (M = Mn, Fe), related to rock salt based Li2MnO3 and LiCoO2. The Li3MnRuO5 oxide adopts a structure related to Li2MnO3 (C2/m) where Li and (Li0.2Mn0.4Ru0.4) layers alternate along the c-axis, while the Li3FeRuO5 oxide adopts a near-perfect LiCoO2 (R3[combining macron]m) structure where Li and (Li0.2Fe0.4Ru0.4) layers are stacked alternately. Magnetic measurements indicate for Li3MnRuO5 the presence of Mn(3+) and low spin configuration for Ru(4+) where the itinerant electrons occupy a π*-band. The onset of a net maximum in the χ vs. T plot at 9.5 K and the negative value of the Weiss constant (θ) of -31.4 K indicate the presence of antiferromagnetic superexchange interactions according to different pathways. Lithium electrochemistry shows a similar behaviour for both oxides and related to the typical behaviour of Li-rich layered oxides where participation of oxide ions in the electrochemical processes is usually found. A long first charge process with capacities of 240 mA h g(-1) (2.3 Li per f.u.) and 144 mA h g(-1) (1.38 Li per f.u.) is observed for Li3MnRuO5 and Li3FeRuO5, respectively. An initial sloping region (OCV to ca. 4.1 V) is followed by a long plateau (ca. 4.3 V). Further discharge-charge cycling points to partial reversibility (ca. 160 mA h g(-1) and 45 mA h g(-1) for Mn and Fe, respectively). Nevertheless, just after a few cycles, cell failure is observed. X-ray photoelectron spectroscopy (XPS) characterisation of both pristine and electrochemically oxidized Li3MRuO5 reveals that in the Li3MnRuO5 oxide, Mn(3+) and Ru(4+) are partially oxidized to Mn(4+) and Ru(5+) in the sloping region at low voltage, while in the long plateau, O(2-) is also oxidized. Oxygen release likely occurs which may be the cause for failure of cells upon cycling. Interestingly, some other Li-rich layered oxides have been reported to cycle acceptably even with the participation of the O(2-) ligand in the reversible redox processes. In the Li3FeRuO5 oxide, the oxidation process appears to affect only Ru (4+ to 5+ in the sloping region) and O(2-) (plateau) while Fe seems to retain its 3+ state.


Subject(s)
Iron/chemistry , Lithium/chemistry , Manganese/chemistry , Oxygen/chemistry , Ruthenium Compounds/chemistry , Electrochemical Techniques , Ions/chemistry , Magnetics , Oxidation-Reduction , Oxides/chemistry , Photoelectron Spectroscopy
4.
Dalton Trans ; 43(37): 14099-108, 2014 Oct 07.
Article in English | MEDLINE | ID: mdl-25124048

ABSTRACT

Aliovalent substitution of Nb(5+) by Ti(4+) in Sr2LuNbO6 is limited to 10% of Nb atoms. A full structural determination by NPD confirms this and reveals that the structure is better described as a superstructure of the simple cubic perovskite (as previously reported) with the monoclinic cell 2(1/2)ap× 2(1/2)ap× 2ap and ß≈ 90° (S.G. P21/n). The substituted materials present both oxygen-vacancies induced by charge compensation and Sr-deficiency. Therefore, their formula should be given as Sr2-yLuNb1-xTixO6-δ. Electrical properties can be fully understood considering these compositional defects. The parent compound Sr2LuNbO6 presents low electrical conductivity in air, which improves by more than one order of magnitude upon Ti substitution. In any case, the title oxides show low electrical conductivity in a wide oxygen partial pressure (pO2) range (10(-25) atm ≤pO2≤ 10(-1) atm). At high pO2 the conductivity increases with pO2 due to oxygen-vacancy annihilation and hole creation, according to a general p-type semiconducting mechanism; A-site substoichiometry and Ti-substitution are the origin of this behaviour. In the low pO2 region, the conductivity increases as the oxygen partial pressure decreases. Reduction of cations, Nb(5+) or Ti(4+), supports n-type conduction by electrons and oxygen vacancy creation. For the intermediate pO2 range a low ionic conduction contribution is observed. Although the estimated ionic conductivity is not high in the substituted compounds, the strategy seems to be valid since a significant enhancement of ionic conduction is observed upon aliovalent substitution.

5.
Phys Chem Chem Phys ; 16(34): 18397-405, 2014 Sep 14.
Article in English | MEDLINE | ID: mdl-25070935

ABSTRACT

The structural features of intercalated Li3AlxTi2-x(PO4)3 compounds, with x = 0 and 0.2, have been deduced by Rietveld analysis of neutron diffraction (ND) patterns recorded between 100 and 500 K. The Li insertion decreases the symmetry from R3̄c to R3̄ in analyzed compounds. In pristine Li1+xAlxTi2-x(PO4)3 samples, Li occupies mainly six-fold M1 sites at ternary axes; but in lithiated Li3AlxTi2-x(PO4)3 samples, Li is located near M2 positions at M3/M3' four-fold coordinated sites. In both cases, Li arrangement minimizes electrostatic Li-Li repulsions. The insertion of lithium resulted in the reduction of Ti(4+) to Ti(3+) that shifts (7)Li, (27)Al and (31)P MAS-NMR resonances towards more positive chemical shifts, improving the resolution of different sites. The detection of twelve components in (7)Li MAS-NMR spectra recorded at room temperature suggests the location of Li(+) ions at three-oxygen faces that define M2 cavities. From (7)Li MAS-NMR spectra, the occupancy of sites and mobility of lithium were investigated in the temperature range 100-500 K. The correlation between structural information, deduced by neutron diffraction, and lithium mobility, deduced by NMR spectroscopy, provides new insights into structural factors that affect lithium mobility in materials with NASICON structure.


Subject(s)
Aluminum Compounds/chemistry , Intercalating Agents/chemistry , Lithium Compounds/chemistry , Lithium/chemistry , Titanium/chemistry , Magnetic Resonance Spectroscopy , Molecular Conformation , Neutron Diffraction
6.
Rev. méd. Chile ; 142(1): 90-97, ene. 2014. ilus, tab
Article in Spanish | LILACS | ID: lil-708856

ABSTRACT

Professional Social Responsibility is now imperative for the practice of medicine. However, there are no instruments to assess it among physicians. Aim: To construct and evaluate the factorial structure and reliability of a questionnaire designed to measure socially responsible behavior in physicians. Material and Methods: The Questionnaire on Medical Socially Responsible Behavior, consisting of 34 items, was constructed. It was applied to 284 physicians and medical students. After eliminating respondents who omitted questions, a valid sample of 214 individuals aged 23 to 67 years (51.4% males) was obtained. We assessed the factorial structure, reliability, discriminative ability of the items and correlation between factors. Results: Exploratory factorial analysis, conducted using the principal axis method, identified the presence of three factors and considered 30 items. The reliability of the factors, assessed using Cronbach's alpha, ranged from 0.73 to 0.89. Only one item had a low correlation of 0.3. Correlations between the three factors were direct and high. Conclusions: The developed questionnaire presents a definite factorial structure, with internally consistent and correlated factors and with adequate psychometric properties.


Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Attitude of Health Personnel , Physicians , Surveys and Questionnaires , Social Responsibility , Students, Medical , Psychometrics , Reproducibility of Results
7.
Inorg Chem ; 52(16): 9290-6, 2013 Aug 19.
Article in English | MEDLINE | ID: mdl-23898863

ABSTRACT

Structural features responsible for lithium conductivity in Li(1+x)Ti(2-x)Al(x)(PO4)3 (x = 0, 0.2, and 0.4) samples have been investigated by Rietveld analysis of high-resolution neutron diffraction (ND) patterns. From structural analysis, variation of the Li site occupancies and atomic thermal factors have been deduced as a function of aluminum doping in the temperature range 100-500 K. Fourier map differences deduced from ND patterns revealed that Li ions occupy M1 sites and, to a lower extent, M3 sites, disposed around ternary axes. The occupation of M1 sites by Li ions is responsible for the preferential expansion of the rhombohedral R3c unit cell along the c axis with temperature. The occupation of less symmetric M3 sites decreases electrostatic repulsions among Li cations, favoring ion conductivity in Li(1+x)Ti(2-x)Al(x)(PO4)3 compounds. The variations detected on long-range lithium motions have been related to variations of the oxygen thermal factors with temperature. The information deduced by ND explains two lithium motion regimes deduced previously by (7)Li NMR and impedance spectroscopy.


Subject(s)
Aluminum/chemistry , Lithium/chemistry , Phosphates/chemistry , Temperature , Titanium/chemistry , Ions/chemistry , Molecular Structure , Neutron Diffraction
8.
Rev Esp Quimioter ; 25(3): 206-15, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22987267

ABSTRACT

OBJECTIVE: To assess the tolerability of liposomal amphotericin B (L-AmB) in critically ill patients with elevated serum creatinine concentrations (Cr) (> 1.5 mg/dL) at starting L-AmB therapy. METHODS: Retrospective, multicenter, comparative study of two cohorts of critically ill patients treated with L-AmB during 3 or more days, the difference between them was the level of Cr at the beginning of treatment. A cutoff value of Cr of 1.5 mg/dL was established. Patients undergoing extrarenal depuration procedures before or 48 hours after starting L-AmB were excluded. The primary endpoint was the difference between Cr values at the end of treatment as compared with Cr at starting L-AmB. Secondary endpoints were treatment-related withdrawals, need of extrarenal depuration techniques, and treatment-related severe adverse events. Demographic data, underlying illness, indication of L-AmB therapy, concomitant risk factors of nephrotoxicity, and vital status at ICU and hospital discharge were recorded. RESULTS: A total of 122 patients admitted to 26 ICUs (16 with Cr > 1.5 g/dL; 106 with normal Cr levels) were recruited. Main reasons for the use of L-AmB in both groups were the broad spectrum of the drug and the presence of hemodynamic instability. L-AmB was administered as first-line treatment in 68.8% of patients with elevated Cr and in 52.8% with normal Cr. The APACHE II score on ICU admission was 25 in patients with elevated Cr and 17 in those with normal Cr values (p < 0.001). Duration of treatment with L-AmB was 16 and 12 days in patients with elevate and normal Cr values, respectively, with a mean dose of 3.5 vs 3.9 mg/kg/day. The use of concomitant nephrotoxic drugs, mortality rate, and ICU and hospital length of stay were similar in both cohorts. In patients with renal function impairment at the initiation of L-AmB treatment, an absolute decrease of Cf-Ci of 1.08 mg/dL was observed (P < 0.001). A decrease of Cr levels to normal limits was observed in 50% of the patients; in 37.5% of patients there was a decrease but normal levels were not achieved, whereas a Cr increased occurred in only one (6.25%) patient. None of the patients required withdrawal of L-AmB or use of extrarenal depuration procedures. Treatment-related severe adverse events were not reported. CONCLUSIONS: In critically ill patients with impaired renal function, the impact of L-AmB on renal function was minimal. L-AmB can be used for the treatment of fungal infections in critically ill patients independently of renal function at the initiation of treatment.


Subject(s)
Amphotericin B/adverse effects , Antifungal Agents/adverse effects , Critical Illness/therapy , Kidney Diseases/complications , Kidney/drug effects , Adolescent , Adult , Aged , Aged, 80 and over , Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , Child , Child, Preschool , Cohort Studies , Creatinine/blood , Female , Humans , Infant , Kidney Function Tests , Male , Middle Aged , Mycoses/complications , Mycoses/drug therapy , Retrospective Studies , Young Adult
9.
Phys Chem Chem Phys ; 14(8): 2892-9, 2012 Feb 28.
Article in English | MEDLINE | ID: mdl-22258437

ABSTRACT

A detailed structural and electrochemical study of the ion exchanged Li(2)Ti(6)O(13) titanate as a new anode for Li-ion batteries is presented. Subtle structural differences between the parent Na(2)Ti(6)O(13), where Na is in an eightfold coordinated site, and the Li-derivative, where Li is fourfold coordinated, determine important differences in the electrochemical behaviour. While the Li insertion in Na(2)Ti(6)O(13) proceeds reversibly the reaction of lithium with Li(2)Ti(6)O(13) is accompanied by an irreversible phase transformation after the first discharge. Interestingly, this new phase undergoes reversible Li insertion reaction developing a capacity of 170 mAh g(-1) at an average voltage of 1.7 V vs. Li(+)/Li. Compared with other titanates this result is promising to develop a new anode material for lithium ion rechargeable batteries. Neutron powder diffraction revealed that Na in Na(2)Ti(6)O(13) and Li in Li(2)Ti(6)O(13) obtained by Na/Li ion exchange at 325 °C occupy different tunnel sites within the basically same (Ti(6)O(13))(2-) framework. On the other hand, electrochemical performance of Li(2)Ti(6)O(13) itself and the phase released after the first full discharge is strongly affected by the synthesis temperature. For example, heating Li(2)Ti(6)O(13) at 350 °C produces a drastic decrease of the reversible capacity of the phase obtained after full discharge, from 170 mAh g(-1) to ca. 90 mAh g(-1). This latter value has been reported for Li(2)Ti(6)O(13) prepared by ion exchange at higher temperature.

10.
Dalton Trans ; 41(6): 1840-7, 2012 Feb 14.
Article in English | MEDLINE | ID: mdl-22167010

ABSTRACT

The half-metallic ferromagnet K(2)Cr(8)O(16) with the hollandite structure has been chemically modified using soft chemistry methods to increase the average oxidation state of chromium. The synthesis of the parent material has been performed under high pressure/high temperature conditions. Following this, different redox reactions have been carried out on K(2)Cr(8)O(16). Oxidation to obtain potassium-de-inserted derivatives, K(2-x)Cr(8)O(16) (0 ≤x≤ 1), has been investigated with electrochemical methods, while the synthesis of sizeable amounts was achieved chemically by using nitrosonium tetrafluoroborate as a highly oxidizing agent. The maximum amount of extracted K ions corresponds to x = 0.8. Upon oxidation the hollandite structure is maintained and the products keep high crystallinity. The de-insertion of potassium changes the Cr(3+)/Cr(4+) ratio, and therefore the magnetic properties. Interestingly, the Curie temperature increases from ca. 175 K to 250 K, getting therefore closer to room temperature.

11.
J Chem Phys ; 135(3): 034109, 2011 Jul 21.
Article in English | MEDLINE | ID: mdl-21786989

ABSTRACT

A study on static polarizabilities for a family of gold clusters (Au(n), n = 6, 12, 20, 34, 54) is presented. For each cluster, a density functional theory perturbation theory calculation was performed to compute the cluster polarizability and the polarizability of each atom in the cluster using Bader's "quantum theory of atoms in molecules" formalism. The cluster polarizability tensor, α(cluster), is expressed as a sum of the atom-in-molecule tensors, α(cluster)=∑(Ω)α(Ω). A strong quadratic correlation (R(2) = 0.98) in the isotropic polarizability of atoms in the cluster and their distance to the cluster center of mass was observed. The cluster polarizabilities are in agreement with previous calculations.


Subject(s)
Gold/chemistry , Quantum Theory , Models, Molecular , Particle Size
12.
J Biol Dyn ; 4(4): 346-80, 2010 Jul.
Article in English | MEDLINE | ID: mdl-22881129

ABSTRACT

The development of spontaneous stationary vegetative patterns in an arid isotropic homogeneous environment is investigated by means of various weakly nonlinear stability analyses applied to the appropriate governing equation for this phenomenon. In particular, that process can be represented by a fourth-order partial differential time-evolution logistic equation for the total plant biomass per unit area divided by the carrying capacity of its territory and defined on an unbounded flat spatial domain. Those patterns that consist of parallel stripes, labyrinth-like mazes, rhombic arrays of rectangular patches, and hexagonal distributions of spots or gaps are generated by the balance between the effects of short-range facilitation and long-range competition. Then those theoretical predictions are compared with both relevant observational evidence and existing numerical simulations as well as placed in the context of the results from some recent nonlinear pattern formation studies.


Subject(s)
Desert Climate , Nonlinear Dynamics , Plant Development/physiology , Models, Biological
13.
J Chem Phys ; 131(2): 021101, 2009 Jul 14.
Article in English | MEDLINE | ID: mdl-19603962

ABSTRACT

A new approach for computing the atom-in-molecule [quantum theory of atoms in molecule (QTAIM)] energies in Kohn-Sham density-functional theory is presented and tested by computing QTAIM energies for a set of representative molecules. In the new approach, the contribution for the correlation-kinetic energy (T(c)) is computed using the density-functional theory virial relation. Based on our calculations, it is shown that the conventional approach where atomic energies are computed using only the noninteracting part of the kinetic energy might be in error by hundreds of kJ/mol.


Subject(s)
Quantum Theory , Algorithms , Ammonia/chemistry , Carbon/chemistry , Hydrogen/chemistry , Oxygen/chemistry , Water/chemistry
14.
J Chem Phys ; 128(7): 074306, 2008 Feb 21.
Article in English | MEDLINE | ID: mdl-18298148

ABSTRACT

The interaction of keV He(+), He(2+), and O(5+) ions with isolated alpha and beta isomers of the amino acid alanine was studied by means of high resolution coincidence time-of-flight mass spectrometry. We observed a strong isomer dependence of characteristic fragmentation channels which manifests in strongly altered branching ratios. Despite the ultrashort initial perturbation by the incoming ion, evidence for molecular rearrangement leading to the formation of H(3)(+) was found. The measured kinetic energies of ionic alanine fragments can be sufficient to induce secondary damage to DNA in a biological environment.


Subject(s)
Alanine/chemistry , Mass Spectrometry/methods , Models, Chemical , Models, Molecular , Computer Simulation , Ions , Isomerism , Molecular Conformation
15.
Rev Alerg Mex ; 54(2): 29-33, 2007.
Article in Spanish | MEDLINE | ID: mdl-17542243

ABSTRACT

BACKGROUND: Asthma has a growing prevalence all over the world. GINA guidelines had improved diagnostic and therapeutic asthma approach, but it is not enough. OBJECTIVE: To evaluate the knowledge about GINA in physicians of first, second and third care level. PARTICIPANTS AND METHODS: Physicians working in first, second and third care level, from medical units related to the Centro Medico Nacional La Raza answered a 19 items questionnaire about GINA. Results were analyzed with Kruskal-Wallis, Pearson's correlation and U of Mann-Whitney tests. RESULTS: We included 179 physicians with an age average of 43 years; 99 or them were 99 females and 80 males. According to medical specialty, Allergy and Immunology had 145 points; Pneumology, 136; Pediatrics, 122; Family Medicine, 81 and Internal Medicine, 78. We found a statistical difference between these specialties (p < 0.0001). Doctors from third and second care level had a higher and significative scoring than first care level colleagues (p < 0.005). We did not find differences between labor years, working schedule and gender with GINA knowledge scoring. CONCLUSIONS: There are differences in GINA knowledge between medical specialties and care level.


Subject(s)
Asthma/therapy , Medical Staff, Hospital/psychology , Physicians/psychology , Practice Guidelines as Topic , Academies and Institutes , Adult , Allergy and Immunology , Cross-Sectional Studies , Family Practice , Female , Humans , Internal Medicine , Knowledge , Male , Mexico , Middle Aged , Pediatrics , Physicians/classification , Pulmonary Medicine , Surveys and Questionnaires
16.
J Inherit Metab Dis ; 29(6): 763, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17041744

ABSTRACT

A patient with atypical infantile Pompe disease suffered acute respiratory insufficiency at the age of 8 years which resulted in complete immobilization and dependence on assisted ventilation. Shortly after initiation of enzyme replacement therapy, she regained her mobility and, after 20 months of treatment, she now leads an almost normal life with limited restrictions.


Subject(s)
Glycogen Storage Disease Type II/drug therapy , Respiratory Insufficiency/drug therapy , alpha-Glucosidases/therapeutic use , Child , Female , Humans , Time Factors , Treatment Outcome
17.
Rev. neurol. (Ed. impr.) ; 33(12): 1101-1105, 16 dic., 2001.
Article in Es | IBECS | ID: ibc-27305

ABSTRACT

Introducción. El coma alfa se define por la aparición en un paciente inconsciente de actividad electroencefalográfica en la banda de frecuencia alfa (8-13 Hz). Objetivo. Determinar en nuestro medio la incidencia, etiología, significado clínico y evolución de coma alfa en pacientes pediátricos con revisión de la literatura. Pacientes y métodos. Se realizó un estudio retrospectivo de aquellos pacientes ingresados en una unidad de cuidados intensivos pediátricos que habían presentado durante su estado de coma neurológico un trazado de actividad alfa. Resultados. Se recogieron sólo 2 pacientes de 5 y 12 años. Ambos eran portadores de una cardiopatía congénita compleja presentando en el primer y décimo día del postoperatorio una parada cardiorrespiratoria. Se practicaron varios EEG mientras persistió el coma y no se utilizó coma barbitúrico. Ambos presentaron un nivel mesencefálico de afectación clínica durante la duración del trazado alfa. Dicho patrón fue bilateral, arreactivo y precedido de un patrón theta, apareció al segundo día de la parada cardiorrespiratoria, se mantuvo durante 2 y 3 días en cada caso y se siguió de un patrón delta. El segundo caso presentó finalmente un trazado de burst-suppression. La TAC fue normal. Ambos pacientes fallecieron a los 4 y 11 días de la aparición del coma alfa. Conclusiones. El coma alfa es muy infrecuente en la infancia. Tanto su etiología como su mal pronóstico son similares a la edad adulta. El coma alfa es un patrón electroencefalográfico transitorio en la evolución del coma que pensamos sea debido a una probable afectación mesencefálica (AU)


Subject(s)
Middle Aged , Child, Preschool , Child , Adult , Male , Female , Humans , Alpha Rhythm , Magnetic Resonance Imaging , Electroencephalography , Brain Mapping , Prefrontal Cortex , Motor Cortex , Motor Activity , Psychomotor Performance , Random Allocation , Retrospective Studies , Reference Values , Basal Ganglia , Cerebellum , Coma , Dominance, Cerebral , Fingers , Hand , Frontal Lobe
18.
BMC Infect Dis ; 1: 21, 2001.
Article in English | MEDLINE | ID: mdl-11722797

ABSTRACT

BACKGROUND: The prevalence of infections by Mycobacterium tuberculosis and non-tuberculous Mycobacterium species in the HIV-infected patient population in Colombia was uncertain despite some pilot studies. We determined the frequency of isolation of Mycobacterium tuberculosis and of non-tuberculous Mycobacterium species in diverse body fluids of HIV-infected patients in Bogota, Colombia. METHODS: Patients who attended the three major HIV/AIDS health care centres in Bogota were prospectively studied over a six month period. A total of 286 patients were enrolled, 20% of them were hospitalized at some point during the study. Sixty four percent (64%) were classified as stage C, 25% as stage B, and 11% as stage A (CDC staging system, 1993). A total of 1,622 clinical samples (mostly paired samples of blood, sputum, stool, and urine) were processed for acid-fast bacilli (AFB) stain and culture. RESULTS: Overall 43 of 1,622 cultures (2.6%) were positive for mycobacteria. Twenty-two sputum samples were positive. Four patients were diagnosed with M. tuberculosis (1.4%). All isolates of M. tuberculosis were sensitive to common anti-tuberculous drugs. M. avium was isolated in thirteen patients (4.5%), but only in three of them the cultures originated from blood. The other isolates were obtained from stool, urine or sputum samples. In three cases, direct AFB smears of blood were positive. Two patients presented simultaneously with M. tuberculosis and M. avium. CONCLUSIONS: Non-tuberculous Mycobacterium infections are frequent in HIV infected patients in Bogota. The diagnostic sensitivity for infection with tuberculous and non-tuberculous mycobacteria can be increased when diverse body fluids are processed from each patient.


Subject(s)
HIV Infections/complications , Tuberculosis/etiology , Adolescent , Adult , Aged , Child , Child, Preschool , Colombia/epidemiology , Female , HIV Infections/microbiology , Humans , Male , Middle Aged , Mycobacterium avium/isolation & purification , Mycobacterium tuberculosis/isolation & purification , Pilot Projects , Tuberculosis/epidemiology , Tuberculosis/microbiology
19.
Rev Neurol ; 33(12): 1101-5, 2001.
Article in Spanish | MEDLINE | ID: mdl-11785044

ABSTRACT

INTRODUCTION: Alpha coma is defined as the appearance, in an unconscious patient, of EEG activity in the alpha frequency band (8-13Hz). OBJECTIVE: To determine, in our setting, the incidence, aetiology, clinical significance and course of alpha coma in paediatric patients and review the literature. PATIENTS AND METHODS: We did a retrospective study of the patients admitted to a paediatric intensive care unit who had alpha activity recorded whilst in coma. RESULTS: Only two patients, aged 5 and 12 years, were found. Both had complex congenital cardiopathy and cardio-respiratory arrest one and twelve days postoperatively, respectively. Several EEGs were done whilst they were in coma. Barbiturate coma was not used. Both had clinical mid-brain involvement during alpha recording. The pattern was bilateral, arreactive and preceded by a theta pattern, appeared two days after the arrest, was maintained for two and three days in the two cases and was followed by delta pattern. The second case finally showed a 'burst-suppression'. The CAT was normal. The patients died 4 and 11 days after the appearance of alpha coma. CONCLUSIONS: Alpha coma is rare in childhood. Both the aetiology and the bad prognosis are similar to that of adults. Alpha coma is a transient EEG pattern occurring during the evolution of coma. We consider it to be due probably to mid-brain involvement.


Subject(s)
Alpha Rhythm , Coma/etiology , Coma/physiopathology , Electroencephalography , Adult , Child , Child, Preschool , Coma/pathology , Humans , Male , Retrospective Studies
20.
J Virol ; 74(20): 9464-70, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11000215

ABSTRACT

The direct effect of a rotavirus nonstructural glycoprotein, NSP4, and certain related peptides on the sodium-coupled transport of D-glucose and of L-leucine was studied by using intestinal brush border membrane vesicles isolated from young rabbits. Kinetic analyses revealed that the NSP4(114-135) peptide, which causes diarrhea in young rodents, is a specific, fully noncompetitive inhibitor of the Na(+)-D-glucose symporter (SGLT1). This interaction involves three peptide-binding sites per carrier unit. In contrast, the Norwalk virus NV(464-483) and mNSP4(131K) peptides, neither of which causes diarrhea, both behave inertly. The NSP4(114-135) and NV(464-483) peptides inhibited Na(+)-L-leucine symport about equally and partially via a different transport mechanism, in that Na(+) behaves as a nonobligatory activator. The selective and strong inhibition caused by the NSP4(114-135) peptide on SGLT1 in vitro suggests that during rotavirus infection in vivo, NSP4 can be one effector directly causing SGLT1 inhibition. This effect, implying a concomitant inhibition of water reabsorption, is postulated to play a mechanistic role in the pathogenesis of rotavirus diarrhea.


Subject(s)
DNA-Directed RNA Polymerases , Intestinal Mucosa/drug effects , Membrane Glycoproteins/antagonists & inhibitors , Monosaccharide Transport Proteins/antagonists & inhibitors , Peptide Fragments/toxicity , Rotavirus/pathogenicity , Viral Nonstructural Proteins/toxicity , Amino Acid Sequence , Animals , Glucose/metabolism , Intestinal Mucosa/metabolism , Intestinal Mucosa/ultrastructure , Leucine/metabolism , Microvilli/metabolism , Molecular Sequence Data , Rabbits , Sodium-Glucose Transporter 1
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