Evaluation of the Hybrid Membrane of ZnO Particles Supported in Cellulose Acetate for the Removal of Lead.

Water polluted by discarded heavy metals such as lead is creating a global pollution problem. In this work, adsorption of Pb(II) was realized in batch studies by a hybrid membrane of cellulose acetate with ZnO particles. First, ZnO particles were prepared by precipitation and immobilized on the membrane. The hybrid membrane was elaborated by interfacial polymerization. The structure and surface were characterized based on Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Batch experiments were carried out under different conditions where the number of particles of ZnO present in the membrane and the pH of the aqueous solution were varied. The Langmuir and Freundlich isotherm models were evaluated in the best adsorption conditions. Data fitted well with a Langmuir model with a maximum adsorption capacity of 15.55 mg·g-1, which was similar for this type of materials. Thermodynamic parameters such as Gibbs free energy, enthalpy, and entropy showed that the process was spontaneous and favorable. The hybrid membrane was evaluated in simulated wastewater of the battery industry with a superior efficiency of up to 97%; without the medium, it did not generate interference. These results suggest that Pb(II) removal by hybrid membrane is possible.

Size exclusion chromatography (SEC-HPLC) as an alternative to study thrombin inhibition.

In vitro analysis of anticoagulant compounds with a potential use as antithrombotic drugs, has been traditionally performed using techniques like spectrophotometry, turbidimetry, as well as electrochemical and clinical assays. Although, these techniques have some disadvantages such as: the inability to measure the total biological activity of thrombin, interferences and, sometimes, the quantitative determination of the inhibition ratio is not accurate. In the present work, the conversion of fibrinogen to fibrin was monitored by molecular exclusion chromatography (SEC-HPLC) in three different reaction systems. An inhibition percentage of 43.19±2.02% was obtained using heparin as an anticoagulant, in addition to the determination of the percentage of heparin bonded to thrombin. This methodology has not been previously described and has high potential for the determination of anticoagulant capacity with higher precision, the determination of thrombin's total biological activity and the quantitative determination of the inhibition ratio.

Effect of hyperprolactinemia on PRL-receptor expression and activation of Stat and Mapk cell signaling in the prostate of long-term sexually-active rats.

The abnormal elevation of serum PRL, referred to as hyperprolactinemia (HyperPRL), produces alterations in several reproductive parameters of male rats such as penile erection or decreased tendency to reach ejaculation. Additionally, this situation produces a significant modification of prostate histology, as observed in the epithelial structure and alveolar area, which could reach a level of hyperplasia in the long-term. In this tissue, HyperPRL produces an increase in expression of PRL receptors and activation of the Stat3 signaling pathway that is correlated with the evolution of prostate pathologies. However, the impact of HyperPRL in long-term sexually active male rats is unknown. In this work, using constantly copulating Wistar male rats with induced HyperPRL, we analyzed the level of serum PRL, the effect on prostate PRL receptors, and activation of pStat3, pStat5 and Mapk signaling pathways. Two procedures to induce HyperPRL were employed, comprising daily IP administration or adenohypophysis transplant, and although neither affected the execution of sexual behavior, the serum PRL profile following successive ejaculations was affected. Messenger RNA expression of the short and long isoforms of the PRL receptor at the ventral prostate was affected in different ways depending on the procedure to induce HyperPRL. The ventral prostate did not show any modification in terms of activation of the pStat5 signaling pathway in subjects with daily administration of PRL, although this was significantly increased in ADH transplanted subjects in the second and fourth consecutive ejaculation. A similar profile was found for the pStat3 pathway which additionally showed a significant increase in the third and fourth ejaculation of daily-injected subjects. The Mapk signaling pathway did not show any modifications in subjects with daily administration of PRL, but showed a significant increase in the second and third ejaculations of subjects with ADH transplants. Thus, although sexual behavior was not modified, HyperPRL modified the expression of PRL receptors and the activation of signal pathways in the prostate tissue. Hence, it is probable that prostatic alterations precede the sexual behavioral deficits observed in subjects with HyperPRL.

Application of an activated carbon-based support for magnetic solid phase extraction followed by spectrophotometric determination of tartrazine in commercial beverages.

A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30 mg L(-1), with a limit of detection of 1 mg L(-1). The method was validated by comparing the results with those obtained by HPLC. A precision of <5.0% was obtained in all cases and no significant differences were observed (P < 0.05).

Correlation of prolactin levels and PRL-receptor expression with Stat and Mapk cell signaling in the prostate of long-term sexually active rats.

Prolactin (PRL) is a key hormone for prostate function, with a basal level in serum and associated with two characteristic circadian peaks. In the male rat, the execution of one bout of sexual behavior with consecutive ejaculations produces a significant transient increase in PRL. However, the impact of a constant sexual life on both PRL levels and prostate function is unknown. Thus, by using constantly copulating males we analyzed the levels of serum PRL, the effect on prostate PRL receptors, and activation of pStat3, pStat5 and Mapk signaling pathways. Sexually experienced Wistar male rats were used, which underwent periodic sessions of sexual behavior tests. Males were subjected to a session of sexual behavior to achieve at least one and up to four ejaculations. Of these, a blood sample was collected from randomly selected males and the ventral prostate was removed for analysis. Serum PRL was quantified, the mRNA for PRL receptors was determined, and signaling pathways were analyzed. Data show that a constant sexual life produced a constant elevation of PRL in serum during four consecutive ejaculations. The ventral prostate showed a different mRNA expression profile for the long and short isoform of the PRL receptor, and both mRNA levels increased. Although the gland did not show modification of the activation of the pStat5 signaling pathway, the levels of pStat3 increased, and the Mapk pathway showed one significant elevation after the third ejaculation. Thus, we showed that an active and constant sexual life produces a sustained increase in serum PRL, its receptors, and the pStat3 signaling pathway. These responses seem to underlie the required physiological need to produce the quantity and quality of prostatic semen to ensure the appropriate environment for sperm to reach and fertilize the ovum.

[SYSTEMATIZATION, ORDER AND SECURITY AS A RESULT OF THE NURSE ASSESSMENT IN PAEDIATRIC EMERGENCY: A METAMORPHOSIS PROCESS]. / Sistemática, orden y seguridad como resultado de la valoración enfermera en la urgencia pediátrica un proceso de metamorfosis.

OBJECTIVE: To determine from the health care professionals perspective the impact on clinical practice of incorporating an assessment tool for primary care paediatric emergency. METHOD: Qualitative study based on the collection of written documents. Twenty-four wide and detailed documents were collected. Thematic analysis was used. RESULTS: Participants were 9 nurses and 7 paediatricians, all with experience in the Paediatric Emergency Department. The results are grouped into three areas: perception of previous situation; benefits perceived; difficulties of the change process related to the triage instrument. The benefits perceived include the achievement of the objectives related to triage as well as collateral benefits for the organization and distribution of structural resources, adequacy of human resources, self-assessment and professional recognition, improvement of team communication and users service perception. The difficulties identified are related to the feasibility of using this instrument when patient flow is high and to the need of specialized training. CONCLUSIONS: All participants perceived more benefits than disadvantages, and both nurses and paediatricians experienced the process as a positive experience. The introduction of the assessment tool had a broader impact than expected.

Determination of quinolones in milk samples using a combination of magnetic solid-phase extraction and capillary electrophoresis.

A magnetic solid-phase extraction (MSPE) method combined with capillary electrophoresis for the simultaneous determination of seven quinolones (QNs) (danofloxacin, ciprofloxacin, marbofloxacin, enrofloxacin, difloxacin, oxolinic acid, and flumequine), using (S)-(+)-6-methoxy-α-methyl-2-naphthaleneacetic acid as internal standard, in milk samples was developed. The variables involved in the preconcentration magnetic procedure were: the composition of the magnetic support composition, the sample pH, and the weight of magnetic adsorbent used. The variables were optimized using a simplex-lattice design. Different magnetite covered with octyl-phenyl silica adsorbents were synthesized by varying the molar ratio of phenyltrimethylsilane and octyltrimethoxysilane; the solids were evaluated for QN preconcentration. Under optimal conditions, a linear range was obtained from 27 to 1000 µg L(-1) with limits of detection ranging from 9 to 12 µg L(-1) for the seven QNs. The absolute recoveries of the seven QNs at three different spiked levels (40, 150, and 400 µg L(-1) ) ranged from 74% to 98% with a relative standard deviation less than 10% in all cases. The proposed method was applied to analyze 20 whole milk samples of different brands. All samples were positive for the presence of QN residues; in some cases, extract dilution was required. The concentrations found are in the range from 31.1 to 5047.3 µg L(-1) . Marbofloxacin was the most frequently found. The method proposed offers advantages in terms of simplicity, sensitivity, efficiency, cost, and analysis time making it an alternative for the analysis of QNs in whole milk samples.

Determination of oxytetracycline in milk samples by polymer inclusion membrane separation coupled to high performance liquid chromatography.

The determination of oxytetracycline in milk samples using a polymer inclusion membrane concept with high performance liquid chromatography (HPLC) was studied. The membranes developed are composed by cellulose acetate as polymer base, Cyanex 923 as carrier and o-nitrophenyl octyl ether as plasticizer. In the optimal conditions, the method exhibits good linearity in the range 0.03-0.20 mg L(-1) with a limit of detection and quantification of 8.2 and 27.3 µg L(-1) respectively. The method was successfully applied to the analysis of milk samples with high selectivity.

Trastornos temporomandibulares: Complejo clínico que el médico general debe conocer y saber manejar. Cátedra especial "Dr. Ignacio Chávez" / Temporomandibular disorders: Clinical complex that the general practitioner must recognize and know how to treat. Special professorship "Dr. Ignacio Chávez"

Los trastornos temporomandibulares (TTM), abarcan un conjunto de problemas clínicos que comprometen diferentes estructuras anatómicas como son: músculos de la masticación, la articulación temporomandibular y estructuras asociadas. Se consideran como una subclasificación de desórdenes musculoesqueléticos y han sido identificados como una causa importante de dolor en la región facial de origen no dentario. Los trastornos temporomandibulares se caracterizan clínicamente por dolor en músculos de la masticación, área preauricular o directamente en la articulación (usualmente agravado por la manipulación y alteración de los movimientos mandibulares principalmente debido a limitación del movimiento), presencia de ruidos articulares como crepitación y chasquidos (clicking). Epidemiológicamente la prevalencia va del 20 al 70% en la población general, motivo por el que creemos que es importante que el médico general tenga el conocimiento básico sobre estos trastornos que generalmente los desconoce y los delega al médico odontólogo. El tratamiento de los TTM va desde fomentar el autocuidado, tratamiento conservador y, de ser necesario, tratamiento quirúrgico.

Temporomandibular disorders (TMDs) are a set of clinical problems that involve different anatomical structures such as masticatory muscles, the temporomandibular joint and related anatomical structures. They are considered a subclass of musculoskeletal disorders and have been identified as a major cause of non-dental facial pain. TMDs are characterized by pain in the masticatory muscles, either in the pre-auricular area or directly in the joint (usually worsened by manipulation or altered movement of the jaw, mainly due to movement limitation) and the presence of clicking sounds during movement. Epidemiologically, TMDs have a prevalence ranging from 20% to 70% in the general population, that is why we believe it is important for the general practitioner to have the basic knowledge about these disorders, often unknown to the general practitioner who leaves the to the odontologist. Treatment includes fostering self-care measures, conservative treatment, or surgical treatment when necessary.

Possible Cis-acting signal that could be involved in the localization of different mRNAs in neuronal axons.

BACKGROUND: Messenger RNA (mRNA) comprises three major parts: a 5'-UTR (UnTranslated Region), a coding region, and a 3'-UTR. The 3'-UTR contains signal sequences involved in polyadenylation, degradation and localization/stabilization processes. Some sequences in the 3'-UTR are involved in the localization of mRNAs in (e.g.) neurons, epithelial cells, oocytes and early embryos, but such localization has been most thoroughly studied in neurons. Neuronal polarity is maintained by the microtubules (MTs) found along both dendrites and axon and is partially influenced by sub-cellular mRNA localization. A widely studied mRNA is that for Tau protein, which is located in the axon hillock and growth cone; its localization depends on the well-characterized cis-acting signal (U-rich region) in the 3'-UTR. METHODS: We compared the cis-acting signal of Tau with mRNAs in the axonal regions of neurons using the ClustalW program for alignment of sequences and the Mfold program for analysis of secondary structures. RESULTS: We found that at least 3 out of 12 mRNA analyzed (GRP75, cofilin and synuclein) have a sequence similar to the cis-acting signal of Tau in the 3'-UTR. This could indicate that these messengers are localized specifically in the axon. The Mfold program showed that these mRNAs have a similar "bubble" structure in the putative sequence signal. CONCLUSION: Hence, we suggest that a U-rich sequence in the 3'-UTR region of the mRNA could act as a signal for its localization in the axon in neuronal cells. Sequences homologous to the DTE sequence of BC1 mRNA could direct the messenger to the dendrites. Messengers with homologues of both types of sequence, e.g. beta-actin, might be located in both dendrites and axon.