Design and implementation of a low-cost multiparameter probe to evaluate the temporal variations of water quality conditions on an estuarine lagoon system.

The measurement of physicochemical variables to infer water quality is important since they help determine the distribution and abundance of aquatic organisms or pollution-related problems. Recently, the development of low-cost probes is a suitable alternative for continuous monitoring of these variables rather than the use of expensive instruments. In this work, a low-cost multiparameter probe (LCMP) has been developed to monitor water quality in an estuary located in Northwestern Mexico during a 3-month period. The LCMP integrates different sensors to an Arduino Nano microcontroller allowing to measure electrical conductivity, dissolved oxygen, pH, salinity, water temperature, and tide level. Data files were stored in a data logger system consisting of a secure digital (SD) card module and a real-time clock module coupled to the Arduino microcontroller. To ensure continuous operation, the system was powered by four 3.7 V, 10,000 mAh rechargeable LiPo batteries. All LCMP components were encapsulated in a polyvinyl chloride pipe. The results show that the LCMP had a good agreement with a commercial-grade multiparameter probe and was able to monitor continuously in hourly time steps. Finally, the LCMP proved to be an alternative for the establishment of coastal observatories, which has been deficient due to limited funding.

Non-covalent functionalization of hexagonal boron nitride nanosheets with guanine.

Density functional theory (DFT) calculations were performed to analyze changes in the structural and electronic properties generated by the interaction of a single nucleobase group (guanine) with the surface of boron nitride nanosheets with hexagonal symmetry (hBNNs). Nanosheets in two contexts were tested: pristine sheets and with point defects (doped with carbon atoms). The criterion of energy minimum was used to find the ground state of the nine possible isomers generated by the hBNNs-guanine interaction. The phenomenon of physisorption is known to occur at values less than 1.0 eV; the adsorption energy results revealed that the preferential geometry was a parallel arrangement between the two partners, with van der Waals-type bonds generated for the hBNNs doped with two carbon atoms. This was the only energetically stable configuration, thus revealing a vibrational mode rather than imaginaries. Furthermore, the hBNNs/C-guanine system has a low value for work function, and therefore could be used in health applications such drug transport and delivery. The increased polarity values suggest that these nanosheets could be solubilized in common solvents used in experimental processes.

Variación esperable de parámetros medidos en el implante y seguimiento de electrodos de fijación activa de marcapasos definitivos / Foreseeable variation in parameters measured at implant and follow-up of permanent pacemaker active fixation electrodes

Objetivos: Analizar la variación de parámetros relativos al electrodo de fijación activa en el implante y seguimiento posterior durante 6 meses de fase aguda de implante. Diseño: Estudio descriptivo, analítico, prospectivo, observacional sobre cohorte de casos sucesivos durante 8 meses (abril-diciembre de 2010). Ámbito: Unidad de electro-estimulación cardiaca de un Servicio de Medicina Intensiva. Pacientes o participantes: Pacientes sometidos a implante de marcapasos definitivo con electrodos de fijación activa, implantados en aurícula y ventrículo, Intervenciones: medición de variables descritas con analizador de umbrales durante la fijación de electrodo y en los diferentes momentos del estudio, Variables principales que se comparan; umbral, impedancia y actividad intrínseca tanto auricular como ventricular antes y después de la fijación del electrodo, a las 48h, al mes y 6 meses de seguimiento, Se realizaron comparaciones utilizando test T-student para datos pareados; con significación si p<0,05 y un test ANOVA para analizar los cambios sucesivos del seguimiento ambulatorio. Resultados: Se analizan 40 pacientes, 19 electrodos auriculares y 40 ventriculares, En la fijación del electrodo varía de forma significativa la impedancia del electrodo auricular (1,188,53±397,26 vs 610,69±326,30 ohmnios, p<0,0001) y ventricular (1,512,93±718,07 vs 768,80±224,90 ohmnios, p>0,0001), A las 48h se suma una disminución del umbral de (..) (AU)

Objectives: To analyze the variations in the parameters relative to active fixation electrodes at the time of implantation and over subsequent follow-up during 6 months of the acute phase of implantation. Design: A descriptive, analytical, prospective, observational cohort study was made of consecutive cases over a period of 8 months (April-December 2010). Setting: Pacing unit of an Intensive Care Unit. Patients or participants: Patients undergoing permanent pacemaker implantation with active fixation electrodes, implanted in both atrium and ventricle, Interventions: Measurement of variables described with a threshold analyzer during electrode fixation and at different times during the study, Main compared variables: threshold, impedance and intrinsic activity (both atrial and ventricular) before and after fixation, at 48hours, at one month and 6 months, Comparisons were made using the Student t-test for paired data, assuming significance for p<0,05, and ANOVA to analyze the successive changes over ambulatory follow-up. Results: We analyzed 40 patients, with 19 atrial and 40 ventricular electrodes, In fixation, the electrodes showed significant variation in the impedance (..) (AU)

[Foreseeable variation in parameters measured at implant and follow-up of permanent pacemaker active fixation electrodes]. / Variación esperable de parámetros medidos en el implante y seguimiento de electrodos de fijación activa de marcapasos definitivos.

OBJECTIVES: To analyze the variations in the parameters relative to active fixation electrodes at the time of implantation and over subsequent follow-up during 6 months of the acute phase of implantation. DESIGN: A descriptive, analytical, prospective, observational cohort study was made of consecutive cases over a period of 8 months (April-December 2010). SETTING: Pacing unit of an Intensive Care Unit. PATIENTS OR PARTICIPANTS: Patients undergoing permanent pacemaker implantation with active fixation electrodes, implanted in both atrium and ventricle, Interventions: Measurement of variables described with a threshold analyzer during electrode fixation and at different times during the study, Main compared variables: threshold, impedance and intrinsic activity (both atrial and ventricular) before and after fixation, at 48 hours, at one month and 6 months, Comparisons were made using the Student t-test for paired data, assuming significance for p<0,05, and ANOVA to analyze the successive changes over ambulatory follow-up. RESULTS: We analyzed 40 patients, with 19 atrial and 40 ventricular electrodes, In fixation, the electrodes showed significant variation in the impedance values of the atrial lead (1,188,53 ± 397,26 vs 610,69 ± 326,30 ohms, p<0,0001) and ventricular lead (1,512,93 ± 718,07 vs 768,80 ± 224,90 ohms, p>0,0001), In the first 48 hours it was coupled with a decrease in ventricular (0,86 ± 0,35 vs 0,48 ± 0,23 volts, p = 0,0001) and atrial pacing threshold (1,10 ± 0,39 vs 0,43 ± 0,23 volts, p = 0,0003), and p-wave sensing (3,61 ± 2,25 vs 2,32 ± 1,09 mV, p = 0,0463), Over follow-up we found the parameters to be stable, with no significant changes. CONCLUSIONS: After active lead fixation, a fall in impedance of the antrial and ventricular is expected, Over the next 48 hours improvement in atrial and ventricular threshold may occur, in contrast to the sensitivity of the intrinsic activity, which reached significance at the P wave measured after 48 hours, These values stabilize over patient follow-up and do not differ significantly in the studied acute patient course.

Granulocytic sarcoma presenting as atypical mastoiditis with facial paralysis: description of a case.

We describe a case of temporal granulocytic sarcoma in a 26-year-old patient after apparent molecular remission of an acute myeloid leukaemia. He complained of otodynia with hearing loss and facial paralysis on the right side. He was treated with chemotherapy and self-transplant haematopoietic stem cells. He was cured clinically, molecular remission of the haematological processes was achieved, and he remained asymptomatic for three years. Facial paralysis and hearing loss associated with temporal GS should be treated with chemotherapy. Aggressive surgery may complicate the clinical course of the disease and it should be avoided.

DNA profiling analysis of 100 consecutive de novo acute myeloid leukemia cases reveals patterns of genomic instability that affect all cytogenetic risk groups.

We have carried out a high-resolution whole genome DNA profiling analysis on 100 bone marrow samples from a consecutive series of de novo acute myeloid leukemia (AML) cases. After discarding copy number changes that are known to be genetic polymorphisms, we found that genomic aberrations (GA) in the form of gains or losses of genetic material were present in 74% of the samples, with a median of 2 GA per case (range 0-35). In addition to the cytogenetically detected aberration, GA were present in cases from all cytogenetic prognostic groups: 79% in the favorable group, 60% in the intermediate group (including 59% of cases with normal karyotype) and 83% in the adverse group. Five aberrant deleted regions were recurrently associated with cases with a highly aberrant genome (e.g., a 1.5 Mb deletion at 17q11.2 and a 750 kb deletion at 5q31.1). Different degrees of genomic instability showed a statistically significant impact on survival curves, even within the normal karyotype cases. This association was independent of other clinical and genetic parameters. Our study provides, for the first time, a detailed picture of the nature and frequency of DNA copy number aberrations in de novo AML.

Identification of Candida tropicalis HSR1, a gene of the heat-shock factor-related family, which confers salt tolerance in Saccharomyces cerevisiae.

A genomic library of Candida tropicalis in a yeast multicopy plasmid has been screened for clones conferring salt tolerance upon transformation into S. cerevisiae. The best halotolerance clone contained an open reading frame encoding a predicted protein of 728 amino acids with homology to transcription factors of the heat-shock family. This novel gene was named HSR1 and is present in single copy in the C. tropicalis genome. Upon transformation into S. cerevisiae it increases the expression of ENA1, a major determinant of salt tolerance encoding a cation-extrusion pump. The sequence of CtHSR1 has been deposited in the EMBL data library under Accession No. AJ296093.

Early risk factors for sepsis in patients with severe blunt trauma.

We studied 43 patients with blunt trauma (injury severity score, > or =25), age >14 years and length of the intensive care unit (ICU) stay >48 h in order to estimate the frequency of sepsis and to identify early risk factors related to its development. Clinical data were collected during the first 24 h and several inflammatory mediators were determined from serum samples of the first 2 days after injury.Twenty-one patients (48.8%) met sepsis criteria during their ICU stay, 9 (20.9%) fulfilled only criteria for sepsis; 6 (13.9%) fulfilled criteria for severe sepsis and another 6 (13.9%) criteria for septic shock. An APACHE II score > or =14, the presence of hypovolemic shock, the need for three or more units of blood to be transfused and the administration of a total volume of fluids > or =10 l were all factors associated significantly with the development of sepsis. In the multivariant analysis, the need for a total volume of fluids > or =10 l was the only independent risk factor (adjusted odds ratio=10.49, 95% CI, 2.34-47.02; P=0.002). No significant differences were documented in relation to the behaviour of the serum markers.

A pea nuclear protein that is induced by dehydration belongs to the vicilin superfamily.

The purification to homogeneity of p16, a protein with an electrophoretic mobility compatible with an apparent molecular mass of 16 kDa, from nuclei of ungerminated pea embryonic axes is described. A cDNA clone of its gene, which was designated psp54, was also isolated. The psp54 cDNA contains an open reading frame coding for a 54.4-kDa polypeptide (p54). p16 corresponds to the C-terminal third of p54, although the mechanisms by which the primary polypeptide could be processed are not yet known. The sequence of p54 is 60% identical with that of the precursor of a sucrose-binding soybean protein, and, to a lesser extent (31-34%), it shares homology with some storage proteins. p16 is also 30% homologous with Nhp2p, a yeast nuclear protein. The psp54 gene, present in a single copy in pea genome, starts being expressed during seed desiccation. Soon after rehydration in seed germination, p54 mRNA disappears and is no longer detectable in vegetative tissues, except in response to hydric stress (exposure to abscisic acid, osmolites or desiccation). p16 can be recovered from nuclei cross-linked to histone H3, when the disulfide bridges that occur in vivo are preserved. On the other hand, p16 shares some properties with dehydrins, which are thought to protect cellular structures against desiccation. We propose that the possible precursor polypeptide p54 belongs to the vicilin superfamily, members of which play a variety of roles. The function of p16 may be related to the protection of chromatin structure against desiccation during seed development.

A study of alternative metal particle structures and mixtures for dental amalgams based on mercury additions.

The perception that mercury in dental amalgam is toxic to the human organism has prompted worldwide efforts by the scientific community to develop alternative amalgam-like materials that utilize little or no mercury. In this investigation, an attempt is made to develop a new dental alloy system by adding liquid mercury to silver-coated Ag4Sn intermetallic particles in lesser amounts than are used in conventional amalgam alloys. An effort to precipitate the important eta-prime (Cu6Sn5) phase was made by adding pure Cu and Sn powders to the alloy formulation during trituration. Tytin a popular Ag-Sn-Cu single-composition, spray-atomized conventional dental alloy was used as the control to obtain baseline data for comparisons of microstructures and mechanical properties. Amalgamation of the coated particles with mercury, with or without the addition of Cu and Sn powders, mostly produced specimens with chemically non-coherent microstructures that were relatively weak in compression. These results were due, in part, to mercury's inability to chemically wet the Ag-coated particles and Cu and Sn powders because of naturally occurring surface oxide films. The strongest specimens tested had silver dendritic coatings, resulting in compression strength values up to 40% of the control's. Their higher strength is attributed to mechanical interlocking at the particle/matrix interfaces.

[Drug-induced agranulocytosis: clinical study of 19 cases]. / Agranulocitosis inducida por fármacos: estudio clínico de 19 casos.

Agranulocytosis is one of the most serious side effects to drugs. From January 1991 to June 1996 were diagnosed 19 cases of agranulocytosis associated with drugs at our hospital (incidence rate: 9.4 over million hab. per year). The average age was 62 and 11 cases were women. The drugs most commonly involved were metamizol and ticlopidine. In 15 of the patients fever blew up and 16 presented some infectious location. In 9 of the cases some positive microbiological culture was obtained, gram-negative bacilli being the commonest. G-CSF was used in 13 of the patients, observing a quicker haematological recovery (5.7 days vs 9.1, p = 0.07), though without any difference in mortality, which was of 0%. All this leads to the following conclusions: a high incidence of agranulocytosis in our environment and the important role of metamizol and ticlopidine in its origin.

The Ssn6-Tup1 repressor complex of Saccharomyces cerevisiae is involved in the osmotic induction of HOG-dependent and -independent genes.

The response of yeast to osmotic stress has been proposed to rely on the HOG-MAP kinase signalling pathway and on transcriptional activation mediated by STRE promoter elements. However, the osmotic induction of HAL1, an important determinant of salt tolerance, is HOG independent and occurs through the release of transcriptional repression. We have identified an upstream repressing sequence in HAL1 promoter (URSHAL1) located between -231 and -156. This promoter region was able to repress transcription from a heterologous promoter and to bind proteins in non-stressed cells, but not in salt-treated cells. The repression conferred by URSHAL1 is mediated through the Ssn6-Tup1 protein complex and is abolished in the presence of osmotic stress. The Ssn6-Tup1 co-repressor is also involved in the regulation of HOG-dependent genes such as GPD1, CTT1, ALD2, ENA1 and SIP18, and its deletion can suppress the osmotic sensitivity of hog1 mutants. We propose that the Ssn6-Tup1 repressor complex might be a general component in the regulation of osmostress responses at the transcriptional level of both HOG-dependent and -independent genes.

[Morbidity characteristics among elderly Mexicans: an analysis of the 1988 National Health Survey]. / Características de la morbilidad en población mexicana de edad avanzada: un análisis de la Encuesta Nacional de Salud 1988.

OBJECTIVE: Based on the 1988 National Health Survey data base, a preliminary approach to an epidemiologic profile of the Mexican elderly is proposed. MATERIAL AND METHODS: This paper analyzes both reported prevalences of some of the principal health problems in Mexicans over 60 years of age and the relationship between selected morbidity, socio-demographic variables and impairment of daily living activities, stratified by age. RESULTS: Results show that: a) the panorama of reported morbidity among the Mexican elderly is a combination of multiple causes, b) socially defined groups present heterogeneous disease patterns, c) selected morbidity is strongly related to daily living activity impairments. CONCLUSIONS: This approach may be used to improve research on living and health conditions of the Mexican elderly.

Multiple transduction pathways regulate the sodium-extrusion gene PMR2/ENA1 during salt stress in yeast.

The yeast PMR2/ENA1 gene encodes an ATPase involved in sodium extrusion and induced by NaCl. At low salt concentrations (0.3 M) induction is mediated by the HOG-MAP kinase pathway, a system activated by non-specific osmotic stress. At high salt concentrations (0.8 M) induction is mediated by the protein phosphatase calcineurin and is specific for sodium. Protein kinase A and Sis2p/Hal3p modulate PMR2/ENA1 expression as negative and positive factors, respectively but Sis2p/Hal3p does not participate in the transduction of the salt signal. Salt stress decreases the level of cAMP and the resulting decrease in protein kinase A activity may contribute to HOG-mediated induction.

[Supply of blood to heart surgery patients. Can transfusion habits be changed?]. / Aportes de sangre a pacientes intervenidos de cirugía cardíaca. Pueden cambiarse los hábitos transfusionales?

OBJECTIVE: In cardiac surgery, patients might receive unnecessary blood transfusions, due to the lack of a uniform criteria for blood replacement. We set out to evaluate the effect of a transfusion education program on the homologous blood requirements of subjects undergoing cardiac surgery. METHODS: In June of 1993 a transfusion education program based on international criteria was designed and put into effect in the intensive care unit. Since that date, 133 patients (group 1), on whom we attempted to evaluate the effects of the program, were included, comparing them with 150 control patients (group 2) from the previous year. Multiple variables were analyzed, in order to confirm that the factors that could affect the use of blood did not differ between the two groups. The impact of these variables and the program on the homologous blood expenditures was measured with uni and multivariant analyses. RESULTS: Blood requirements of the patients during the first day of the postoperative period were 0.9 +/- 0.1 U in group 1 versus 1.8 +/- 0.1 U in group 2 (p < 0.001) and the requirements during their entire stay in ICU were 1.8 +/- 0.1 versus 2.6 +/- 0.1 (p < 0.005). There were significant differences between both groups: Hemoglobin level at the admission in ICU, anoxia time, extracorporal circulation time, and blood losses in the first 24 hours of their stay in ICU. However, the analysis of covariance showed that the transfusion program exerted an independent influence, apart from other variables, over the decrease of blood transfusions. Morbidity and mortality were similar in both groups. CONCLUSIONS: Transfusion habits can be modified, permitting a lesser consumption of homologous blood through the adoption of education programs adapted to the diseases in which they will be applied.

Pharmacological evidence for interactions between 5-HT1A receptor agonists and subtypes of alpha 1-adrenoceptors on rabbit aorta.

This study was designed to determine if alpha 1-adrenoceptors are involved in the vascular responses to 5-HT1A receptor agonists. Buspirone (3.1 x 10(-7)-3.1 x 10(-5) M) and 8-hydroxy-2(di-N-propylamino)tetralin (8-OH-DPAT; 3.1 x 10(-6)-10(-4) M) elicited contractions of rabbit aorta rings which were blocked by prazosin (10(-9)-5.6 x 10(-9) M), but which were unaffected by reserpine pretreatment (1 mg/kg i.p.). 5-Methylurapidil (10(-7) and 10(-6) M) blocked contractions elicited by 8-OH-DPAT and by buspirone, whereas chloroethylchonidine (10(-5) and 10(-4) M) inhibited only the effect of buspirone. In addition, these 5-HT1A receptor agonists relaxed arteries precontracted with alpha-adrenoceptor agonists in a similar range of concentrations in which they elicited contraction. Moreover, 8-OH-DPAT and buspirone protected the alpha-adrenoceptors from the irreversible blockade provoked by phenoxybenzamine (10(-7) M), as judged by the norepinephrine contraction and stimulated phosphatidylinositol labeling. According to these results the contractile and relaxant effects elicited by 5-HT1A receptor agonists are a consequence of a direct interaction with alpha 1-adrenoceptors. The contraction elicited by 8-OH-DPAT may be mediated by alpha 1A-adrenoceptors, whereas both alpha 1A- and alpha 1B-adrenoceptors may mediate the effect of buspirone in rabbit aorta.

[Antibiotic therapy in post-cesarean endomyometritis. Comparison of ampicillin-gentamicin and ampicillin-metronidazole regimens]. / Antibióticoterapia en endomiometritis postcesárea. Comparación de los esquemas ampicilina-gentamicina y ampicilina-metronidazol.

Two therapeutic combinations for the treatment of post-cesarean endomyometritis are compared: A, ampicillin plus gentamycin; B, penicillin plus metronidazole, in 40 patients. There were no failures with any of the combinations. However, hospital stay and the time elapsed for resuturing a dehiscent surgical wound, as well as the average cost of treatment, were significantly less for combination B.