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1.
J Investig Allergol Clin Immunol ; 33(2): 95-101, 2023 Apr 18.
Article in English | MEDLINE | ID: mdl-36069440

ABSTRACT

Suspected or confirmed antibiotic allergy is a frequent clinical circumstance that influences antimicrobial prescription and often leads to the avoidable use of less efficacious and/or more toxic or costly drugs than first-line antimicrobials. Optimizing antimicrobial therapy in patients with antibiotic allergy labels has become one of the priorities of antimicrobial stewardship programs in several countries. These guidelines aim to make recommendations for the systematic approach to patients with suspected or confirmed antibiotic allergy based on current evidence. An expert panel (11 members of various scientific societies) formulated questions about the management of patients with suspected or confirmed antibiotic allergy. A systematic literature review was performed by a medical librarian. The questions were distributed among panel members who selected the most relevant references, summarized the evidence, and formulated graded recommendations when possible. The answers to all the questions were finally reviewed by all panel members. A systematic approach to patients with suspected or confirmed antibiotic allergy was recommended to improve antibiotic selection and, consequently, clinical outcomes. A clinically oriented, 3-category risk-stratification strategy was recommended for patients with suspected antibiotic allergy. Complementary assessments should consider both clinical risk category and preferred antibiotic agent. Empirical therapy recommendations for the most relevant clinical syndromes in patients with suspected or confirmed ß-lactam allergy were formulated, as were recommendations on the implementation and monitoring of the impact of the guidelines. Antimicrobial stewardship programs and allergists should design and implement activities that facilitate the most appropriate use of antibiotics in these patients.


Subject(s)
Communicable Diseases , Drug Hypersensitivity , Hypersensitivity , Pharmacy Service, Hospital , Humans , Coronary Care Units , Anti-Bacterial Agents/adverse effects , Communicable Diseases/drug therapy , Drug Hypersensitivity/therapy , Drug Hypersensitivity/drug therapy , Hypersensitivity/drug therapy
3.
Phys Rev Lett ; 121(25): 257701, 2018 Dec 21.
Article in English | MEDLINE | ID: mdl-30608792

ABSTRACT

We demonstrate the Josephson effect in a serial double quantum dot defined in a nanowire with epitaxial superconducting leads. The supercurrent stability diagram adopts a honeycomb pattern. We observe sharp discontinuities in the magnitude of the critical current, I_{c}, as a function of dot occupation, related to doublet to singlet ground state transitions. Detuning of the energy levels offers a tuning knob for I_{c}, which attains a maximum at zero detuning. The consistency between experiment and theory indicates that our device is a faithful realization of the two-impurity Anderson model.

4.
Exp Parasitol ; 166: 116-23, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27068784

ABSTRACT

Congenital transmission of Toxoplasma gondii may occur if the mother gets infected for the first time while pregnant. The risk of mother-to-child transmission depends on the gestation trimester at infection, being lowest in the first and highest in the last. Conversely, fetal damage is frequent and more severe at the beginning of pregnancy. The objective of this study was to evaluate congenital transmission and pathological aspects in the placenta and the fetus using a mouse model of congenital infection of the second gestation third. Forty-five female BALB/c mice were infected intravenously with 2.5-10.0 × 10(6) tachyzoites of the ME49 strain at middle gestation. Samples of maternal spleen and fetal/placental units were taken 72 h later. We determined parasite load and vertical transmission by qPCR, as well as damage macroscopically and by histopathology. With the lowest dose, 18% of the fetuses were infected. Also, 40% of fetuses/litter were altered, while this value was 10% in the control group (P < 0.05). These results are similar to those described in humans in terms of vertical transmission and fetal damage during the second third of gestation. The maternal spleen had 10-1000 times more tachyzoites than the placenta, and the later retained 90-99% of the parasites that could reach the fetus. Nevertheless, we found resorptions, abortions or fetal tissue damage in the presence but also in the absence of parasites. Our data indicate a strong protective effect of maternal organs and the placenta against fetal infection, but extensive damage of the later may led to resorption or abortion without vertical transmission.


Subject(s)
Fetus/parasitology , Infectious Disease Transmission, Vertical , Placenta/parasitology , Pregnancy Complications, Parasitic/parasitology , Toxoplasmosis, Animal/congenital , Animals , DNA-Binding Proteins/genetics , Disease Models, Animal , Embryo Loss/parasitology , Female , Fetus/pathology , Hemorrhage , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Necrosis , Parasite Load , Placenta/pathology , Pregnancy , Pregnancy Complications, Parasitic/pathology , Specific Pathogen-Free Organisms , Spleen/parasitology , Thrombosis , Toxoplasmosis, Animal/pathology , Toxoplasmosis, Animal/transmission
5.
J Struct Biol ; 177(2): 349-57, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22197647

ABSTRACT

Black corals (antipatharians) are colonial cnidarians whose branched tree-like skeleton is mostly constituted of chitin fibrils inside a lipoproteic matrix. The skeleton exhibits growth rings formed by chitin layers (micro-lamellae). In order to know the effect of the arrangement microlamellae of chitin of black corals and to improve the understanding of the role of chitin structure in the antipatharian skeleton, the mechanical properties of the skeleton of two black corals, Antipathes caribbeana and Antipathes pennacea, were examined using nanoindentation tests. Measurements of reduced elastic modulus, nanohardness and the viscoelastic behavior were measured with a spheroconical indenter. The results indicate variations in the values of the mechanical properties clearly associated with different structures present in the skeletons, the core being the one that invariably shows the maximum values. The solid multilamellar arrangement of black coral chitin, its viscoelastic behavior, and the anisotropic mechanical response, are relevant factors contributing to the successful adaptation of black coral colonies to shallow as well as to very deep waters.


Subject(s)
Anthozoa/anatomy & histology , Chitin/metabolism , Algorithms , Animals , Anthozoa/metabolism , Biomechanical Phenomena , Elastic Modulus , Microscopy, Atomic Force , Surface Properties
6.
Diabetologia ; 53(1): 66-9, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19841892

ABSTRACT

AIMS/HYPOTHESIS: We wanted to identify a five-item short form of the Problem Areas in Diabetes Scale and a single-item measure for rapid screening of diabetes-related emotional distress. METHODS: Using an existing database of 1,153 patients with diabetes, we conducted a principal-components analysis to identify a set of five items and then conducted a reliability analysis and validity checks. From those five items, we identified the item with the strongest psychometric properties as a one-item screening tool. RESULTS: We identified a reliable and valid short version of the Problem Areas in Diabetes Scale (PAID) comprising five of the emotional-distress questions of the full PAID items (PAID-5, with items 3, 6, 12, 16, 19). The PAID-5 has satisfactory sensitivity (94%) and specificity (89%) for recognition of diabetes-related emotional distress. We also identified a one-item screening tool, the PAID-1 (Question 12: Worrying about the future and the possibility of serious complications), which has concurrent sensitivity and specificity of about 80% for the recognition of diabetes-related emotional distress. CONCLUSIONS/INTERPRETATION: The PAID-5 and PAID-1 appear to be psychometrically robust short-form measures of diabetes-related emotional distress.


Subject(s)
Diabetes Mellitus/psychology , Emotions , Stress, Psychological/etiology , Diet, Diabetic/psychology , Employment , Female , Humans , Hypoglycemic Agents/therapeutic use , Insulin/therapeutic use , Male , Middle Aged , Psychometrics , Sensitivity and Specificity , Social Support , Stress, Psychological/diagnosis
7.
Opt Express ; 18(16): 16406-17, 2010 Aug 02.
Article in English | MEDLINE | ID: mdl-20721027

ABSTRACT

We use two different synthesis approaches for the preparation of TiO(2) films in order to study their resulting third order optical nonlinearity, and its modification by the inclusion of Au nanoparticles in one of the samples. An ultrasonic spray pyrolysis method was used for preparing a TiO(2) film in which we found two-photon absorption as a dominant nonlinear effect for 532 nm and 26 ps pulses; and a purely electronic nonlinearity at 830 nm for 80 fs pulses. A strong optical Kerr effect and the inhibition of the nonlinear optical absorption in 532 nm can be obtained for the first sample if Au nanoparticles embedded in a second TiO(2) film prepared by a sol-gel technique are added to it. We used an optical Kerr gate, z-scan, a multi-wave mixing experiment and an input-output transmittance experiment for measuring the optical nonlinearities.


Subject(s)
Gold , Metal Nanoparticles/chemistry , Models, Chemical , Photochemistry/methods , Photons , Scattering, Radiation , Titanium/chemistry , Absorption , Computer Simulation , Membranes, Artificial , Nonlinear Dynamics
8.
J Comp Pathol ; 176: 151-155, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32359629

ABSTRACT

Adipositas cordis (AC) is a rare cardiomyopathy characterized by fatty infiltration of the myocardium without signs of tissue destruction or inflammation. Its diagnosis is challenging and requires histopathological examination. This study describes such cardiomyopathy in two cats that died suddenly. In both cases, anatomopathological examination showed gross lesions indicative of acute heart failure, associated with an increase in subepicardial fat, particularly in the right ventricle. Microscopically, there was an increased amount of subepicardial and intramyocardial adipose tissue in the right ventricular free wall, without signs of cellular degeneration, inflammatory infiltration, necrosis or fibrosis, confirmed by histochemical staining. AC is a rare cardiac pathology, but it should be taken into consideration in feline medicine when a sudden death occurs.


Subject(s)
Adipose Tissue/pathology , Cardiomyopathies/veterinary , Cat Diseases/pathology , Death, Sudden, Cardiac/veterinary , Myocardium/pathology , Animals , Cats , Female , Male
9.
Clin Transl Oncol ; 22(4): 457-467, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31240462

ABSTRACT

The elderly form a very heterogeneous group in relation to their general health state, degree of dependence, comorbidities, performance status, physical reserve and geriatric situation, so cancer treatment in the older patient remains a therapeutic challenge. The physiological changes associated with aging increase the risk of developing a serious toxicity induced by chemotherapy treatment, as well as other undesirable consequences as hospitalizations, dependence and non-compliance with treatment, that can negatively affect survival, quality of life and treatment efficacy. The use of hematopoietic growth factors and other active supportive interventions in the elderly can help prevent and/or alleviate these toxicities. However, we have little data on the efficacy and tolerance of support treatments in the older patient. The objective of this work is to review the most frequent toxicities of oncological treatments in the elderly and their management.


Subject(s)
Antineoplastic Agents/adverse effects , Molecular Targeted Therapy/adverse effects , Neoplasms/drug therapy , Aged , Anemia/therapy , Cardiovascular System/drug effects , Diarrhea/therapy , Fatigue/therapy , Geriatric Assessment , Humans , Neutropenia/therapy , Patient Compliance
10.
Acta Ortop Mex ; 34(5): 309-312, 2020.
Article in Spanish | MEDLINE | ID: mdl-33634635

ABSTRACT

Distal femur pseudoarthrosis also called «distal femur non-union¼ (DFNU) represents a rare complication associated with a fracture caused by high-energy trauma; its treatment is controversial, as there is a wide variety of surgical techniques that can be implemented, from open reduction plus internal fixation with plates, to the use of fixed angle plates combined with bone autograft. We expose the case of a 24-year-old man who shows up for consultation with the history of having presented a left femoral supracondylar fracture with a year of evolution, treated by osteosynthesis of the distal femur with dynamic condylar screws (DCS plate); developed a torpid evolution with severe pain in the distal third of the left thigh and functional limitation, developed a progressive varus deformity of the left thigh that caused a shortening of 3.8 cm of the limb. A focus of pseudoarthrosis was identified, which was surgically removed, the intramedullary canal was recanalized, and a lateral closed wedge osteotomy was performed to correct the angulation and allow reduction. 5.5 mm (three proximal and three distal) hydroxyapatite screws and an external fixator were placed. In addition, a review of the literature focused on the use of external fixation was carried out as a treatment for the pseudoarthrosis of the distal femur.


La seudoartrosis del fémur distal, también llamada «no unión del fémur distal¼ (NUFD), representa una complicación poco frecuente asociada a una fractura causada por un traumatismo de alta energía; su tratamiento es controversial, ya que existe una gran variedad técnicas quirúrgicas que pueden ser implementadas desde la reducción abierta más la fijación interna con placas hasta el uso de placas de ángulo fijo combinadas con autoinjerto óseo. Exponemos el caso de un hombre de 24 años de edad, el cual se presenta a la consulta con el antecedente de haber sufrido una fractura supracondílea femoral izquierda con un año de evolución, tratada mediante una osteosíntesis del fémur distal con tornillos condilares dinámicos (placa DCS); mostró una evolución tórpida con dolor severo en el tercio distal del muslo izquierdo y limitación funcional, desarrolló una deformidad en varo progresiva del muslo izquierdo que causó un acortamiento de 3.8 cm de la extremidad. Se identificó un foco de seudoartrosis, el cual se retiró quirúrgicamente, se recanalizó el canal intramedular y se realizó una osteotomía de cuña cerrada lateral para corregir la angulación y permitir la reducción. Se colocaron tornillos de hidroxiapatita de 5.5 mm (tres proximales y tres distales) y un fijador externo. Además se hizo una revisión de la literatura enfocada en el uso de la fijación externa como tratamiento de la seudoartrosis del fémur distal.


Subject(s)
Femoral Fractures , Pseudarthrosis , Adult , Bone Plates , External Fixators , Femoral Fractures/surgery , Femur/surgery , Fracture Fixation , Fracture Fixation, Internal , Humans , Male , Pseudarthrosis/surgery , Treatment Outcome , Young Adult
11.
Prostaglandins Other Lipid Mediat ; 90(3-4): 63-8, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19723588

ABSTRACT

Endothelin-1 (ET-1) has been reported to mediate prostaglandin (PG) F(2)alpha (PGF(2)alpha)-induced luteolysis. Prostaglandins E (PGE; PGE(1)+PGE(2)) are associated with implantation, maternal recognition of pregnancy, and are antiluteolytic and luteotropic in vitro and in vivo. ET-1 increased PGE secretion by bovine luteal tissue in vitro from cows where estrus was not synchronized or when estrus was synchronized with lutalyse and did not affect luteal PGF(2)alpha or progesterone secretion, which does not support the concept that ET-1 is luteolytic or mediates PGF(2)alpha luteolysis. Therefore, the objective of this experiment was to determine whether ET-1 infused every 6h from 2400 h on day 10-1800 h on day 18 of the ovine estrous cycle either into the interstitial tissue of the ovarian vascular pedicle (IP) or intrauterine (IU) adjacent to the luteal-containing ovary was luteolytic in ewes. Treatments were: Vehicle-IP; Vehicle-IU; ET-1-IP; or ET-1-IU. Weights of corpora lutea differed (P< or = 0.05) among treatment groups. Weights of corpora lutea at 1800 h on day 18 were: VEH-IP-247+/-38 mg; VEH-IU-195+/-31 mg; ET-1-IP-626+/-74 mg; and ET-1-IU-542+/-69 mg. Luteal weights on day 18 in ET-1-IP or ET-1-IU-treated ewes did not differ (P> or =0.05), but were heavier (P< or =0.05) than in the Vehicle-IP or Vehicle-IU treatment groups which did not differ (P> or =0.05). Profiles of progesterone in jugular venous plasma of both control groups treated with Vehicle-IP or Vehicle-IU were lower (P< or =0.05) than in ewes treated with ET-1-IP or ET-1-IU, which did not differ (P> or =0.05) between ET-1-IP or ET-1-IU treatment groups. Treatment with ET-1-IP or ET-1-IU increased (P< or =0.05) the PGE:PGF(2)alpha ratio when compared to the Vehicle-IP or Vehicle-IU treatment groups, which did not differ (P> or =0.05) between each other. In summary, ET-1 prevented the decrease in luteal weights and the decline in progesterone, but increased the PGE:PGF(2)alpha ratio when compared to controls. Therefore, it is concluded that ET-1 is not luteolytic in ewes, but instead may be luteotropic or antiluteolytic by altering uterine secretion of the PGE:PGF(2)alpha ratio, since PGE(1) or PGE(2) are luteotropic in vitro and in vivo, PGE(1) or PGE(2) prevent PGF(2)alpha-induced luteolysis in vitro and in vivo, and PGE(1) and PGE(2) increase two-fold in ewe endometrium to prevent luteolysis during early pregnancy.


Subject(s)
Corpus Luteum/physiology , Endothelin-1/physiology , Luteolysis/physiology , Sheep/physiology , Animals , Dinoprost/blood , Female , Organ Size , Pregnancy , Progesterone/blood , Prostaglandins E/blood , Sheep/blood
12.
Rev Clin Esp (Barc) ; 219(4): 184-188, 2019 May.
Article in English, Spanish | MEDLINE | ID: mdl-30651196

ABSTRACT

BACKGROUND AND OBJECTIVES: The ω-5 gliadin (ω5G) is considered the main allergen in wheat-dependent exercise-induced anaphylaxis (WDEIA). These patients experience anaphylactic reactions after consuming wheat and performing physical exercise. The aim of our study was to describe the main characteristics of 12 patients with this diagnosis. MATERIAL AND METHODS: A descriptive, retrospective study was conducted by reviewing the medical records of 12 patients diagnosed with ω-5G hypersensitivity. RESULTS: The patients' mean age was 37 years, with 50% men and 50% women. Most of the patients had a history of similar unexamined episodes. The latency period varied from immediate to 150min. The most common symptoms were urticaria (83%), bronchospasms (58%), angio-oedema (42%), hypotension (25%) and gastrointestinal symptoms (16%). The most often involved cofactor was physical exercise. The allergy study was conducted with prick tests and total and specific IgE readings. CONCLUSIONS: WDEIA is a relatively rare but potentially severe food allergy. Understanding this allergy is therefore important for a correct diagnosis.

13.
Sci Adv ; 5(7): eaav1235, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31281880

ABSTRACT

A semiconductor nanowire with strong spin-orbit coupling in proximity to a superconductor is predicted to display Majorana edge states emerging under a properly oriented magnetic field. The experimental investigation of these exotic states requires assessing the one-dimensional (1D) character of the nanowire and understanding the superconducting proximity effect in the presence of a magnetic field. Here, we explore the quasi-ballistic 1D transport regime of an InAs nanowire with Ta contacts. Fine-tuned by means of local gates, the observed plateaus of approximately quantized conductance hide the presence of a localized electron, giving rise to a lurking Coulomb blockade effect and Kondo physics. When Ta becomes superconducting, this local charge causes an unusual, reentrant magnetic field dependence of the supercurrent, which we ascribe to a 0 - π transition. Our results underline the relevant role of unintentional charge localization in the few-channel regime where helical subbands and Majorana quasi-particles are expected to arise.

14.
J Pineal Res ; 45(2): 219-23, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18373556

ABSTRACT

Caustic ingestion is one of the most life-threatening events in the pediatric age group, which requires the immediate management and subsequent treatment of its most significant complication, i.e. alterations in esophageal structure. We investigated whether melatonin could reduce the esophageal burn damage induced by sodium hydroxide. It was assumed that melatonin could be effective because of its function as a direct free radical scavenger, its antioxidative actions and its ability to diminish tissue hydroxyproline (HP) levels. Esophageal burns were induced in male rats by the administration of 10% sodium hydroxide. Lipid peroxidation (LPO) products were then measured at the following times: 0, 1, 6, 24, 48 and 72 hr after treatment. Tissue HP concentrations in the injured area were assessed at 14 days after the administration of sodium hydroxide. The groups received either systemic melatonin or normal saline. There were two, non-ischemic, sham control groups treated with or without melatonin. LPO products, malondialdehyde (MDA) and 4-hydroxyalkenal (4-HDA), increased immediately after the administration of sodium hydroxide; this indicates the participation of free radicals in the development of damage. Melatonin diminished the oxidative response and the amount of HP in the late phase of the lesion. Melatonin reduced oxidative damage in the early phase of the esophageal burns induced by sodium hydroxide.


Subject(s)
Burns, Chemical/drug therapy , Esophagus/drug effects , Melatonin/pharmacology , Protective Agents/pharmacology , Animals , Antioxidants/pharmacology , Burns, Chemical/etiology , Esophagus/injuries , Esophagus/metabolism , Hydroxyproline/metabolism , Lipid Peroxidation/drug effects , Male , Malondialdehyde/metabolism , Rats , Rats, Sprague-Dawley , Sodium Hydroxide/toxicity
15.
Clin Transl Oncol ; 20(10): 1246-1251, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29633183

ABSTRACT

Population aging is associated with greater numbers of older people with cancer. Thanks to treatment advances, not only are more seniors diagnosed with cancer, but there are also more and more older cancer survivors. This upward trend will continue. Given the heterogeneity of aging, managing older patients with cancer poses a significant challenge for Medical Oncology. In Spain, a Geriatric Oncology Task Force has been set up within the framework of the Spanish Society for Medical Oncology (SEOM). With the aim of generating evidence and raising awareness, as well as helping medical oncologists in their training with respect to seniors with cancer, we have put together a series of basic management recommendations for this population. Many of the patients who are assessed in routine clinical practice in Oncology are older. CGA is the basic tool by means of which to evaluate older people with cancer and to understand their needs. Training and the correct use of recommendations regarding treatment for comorbidities and geriatric syndromes, support care, and drug-drug interactions and toxicities, including those of antineoplastic agents, as detailed in this article, will ensure that this population is properly managed.


Subject(s)
Aged , Medical Oncology/standards , Neoplasms/therapy , Geriatric Assessment/methods , Humans , Medical Oncology/methods
16.
Clin Transl Oncol ; 20(8): 1087-1092, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29327240

ABSTRACT

INTRODUCTION: Geriatric oncology (GO) is a discipline that focuses on the management of elderly patients with cancer. The Spanish Society of Medical Oncology (SEOM) created a Working group dedicated to geriatric oncology in February 2016. OBJECTIVES: The main goal of this study was to describe the current situation in Spain regarding the management of elderly cancer patients through an online survey of medical oncologists. METHODS: A descriptive survey was sent to several hospitals by means of the SEOM website. A personal e-mail was also sent to SEOM members. RESULTS: Between March 2016 and April 2017, 154 answers were collected. Only 74 centers (48%) had a geriatrics department and a mere 21 (14%) medical oncology departments had a person dedicated to GO. The vast majority (n = 135; 88%) had the perception that the number of elderly patients with cancer seen in clinical practice had increased. Eighteen (12%) oncologists had specific protocols and geriatric scales were used at 55 (31%) centers. Almost all (92%) claimed to apply special management practices using specific tools. There was agreement that GO afforded certain potential advantages. Finally, 99% of the oncologists surveyed believed it and that training in GO had to be improved. CONCLUSIONS: From the nationwide survey promoted by the Spanish Geriatric Oncology Working Group on behalf of SEOM, we conclude that there is currently no defined care structure for elderly cancer patients. There is an increasing perception of the need for training in GO. This survey reflects a reality in which specific needs are perceived.


Subject(s)
Delivery of Health Care/standards , Geriatric Assessment , Geriatrics/standards , Medical Oncology/standards , Neoplasms/therapy , Oncologists/standards , Patient Care Team/standards , Aged , Delivery of Health Care/organization & administration , Humans , Spain , Surveys and Questionnaires
17.
J Chromatogr B Analyt Technol Biomed Life Sci ; 852(1-2): 353-61, 2007 Jun 01.
Article in English | MEDLINE | ID: mdl-17347057

ABSTRACT

An investigation of the use of the chromatographic retention (log k) as an in vitro approach for modelling the toxicity to Fathead Minnows of anilines and phenols is developed. A data set of 65 compounds with available experimental toxicity data was used. Log k data at three pH values were used for the compounds classification and two groups or 'MODEs' were identified. For one 'MODE' a quantitative retention-activity relationship (QRAR) model was calculated. Finally, it was used to estimate the toxicity to Fathead minnows of anilines and phenols for which experimental data are not available. These estimations were compared to those obtained from another toxicity (to Tetrahymena pyriformis) data set and those estimated from a U.S. EPA QSAR approach (ECOSAR software) to decide on the toxicity level according to the Directive 3/21/EEC.


Subject(s)
Aniline Compounds/toxicity , Chromatography, Micellar Electrokinetic Capillary/methods , Phenols/toxicity , Aniline Compounds/chemistry , Animals , Cyprinidae , Phenols/chemistry , Quantitative Structure-Activity Relationship , Spectrophotometry, Ultraviolet , Tetrahymena pyriformis/drug effects
18.
Chemosphere ; 69(1): 108-17, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17553545

ABSTRACT

An investigation of the use of the chromatographic retention (log k) as an in vitro approach for modeling the pH-dependence of the toxicity to Guppy of phenols is developed. A data set of 19 phenols with available experimental toxicity-pH data was used. The importance of the mechanism of toxic action (MOA) of phenols was studied. log k data at three pH values were used for the phenols classification and two groups or 'MODEs' were identified. For one 'MODE' a quantitative retention-activity relationship (QRAR) model was calculated. Finally, the model was used to assess the toxicity to Guppy of phenols at different pH values. The results of this investigation suggest that chromatographic retention data allows fish toxicity modeling, in the 5.5-8 pH range of interest.


Subject(s)
Models, Biological , Phenols/chemistry , Phenols/toxicity , Animals , Chromatography , Forecasting , Hydrogen-Ion Concentration , Lethal Dose 50 , Poecilia , Quantitative Structure-Activity Relationship
19.
J Pharm Biomed Anal ; 40(2): 312-21, 2006 Feb 13.
Article in English | MEDLINE | ID: mdl-16182504

ABSTRACT

Rapid chromatographic procedures for analytical quality control of pharmaceutical preparations containing antihistamine drugs, alone or together with other kind of compounds are proposed. The method uses C18 stationary phases and micellar mobile phases of cetyltrimethylammonium bromide (CTAB) with either 1-propanol or 1-butanol as organic modifier. The proposed procedures allow the determination of the antihistamines: brompheniramine, chlorcyclizine, chlorpheniramine, diphenhydramine, doxylamine, flunarizine, hydroxyzine, promethazine, terfenadine, tripelennamine and triprolidine, in addition to caffeine, dextromethorphan, guaifenesin, paracetamol and pyridoxine in different pharmaceutical presentations (tablets, capsules, suppositories, syrups and ointments). The methods require minimum handling sample and are rapid (between 3 and 12 min at 1 mLmin(-1) flow rate) and reproducible (R.S.D. values<5%). Limits of detection are lower than 1 microgmL(-1) and the recoveries of the analytes in the pharmaceutical preparations are in the range 100+/-10%.


Subject(s)
Chromatography, Liquid/methods , Histamine H1 Antagonists/analysis , Pharmaceutical Preparations/chemistry , 1-Butanol , 1-Propanol , Brompheniramine/analysis , Cetrimonium , Cetrimonium Compounds , Chlorpheniramine/analysis , Dosage Forms , Micelles , Piperazines/analysis , Reproducibility of Results , Time Factors
20.
Article in English | MEDLINE | ID: mdl-26382456

ABSTRACT

We investigate the role of migration patterns on the spread of epidemics in complex networks. We enhance the SIS-diffusion model on metapopulations to a nonlinear diffusion. Specifically, individuals move randomly over the network but at a rate depending on the population of the departure patch. In the absence of epidemics, the migration-driven equilibrium is described by quantifying the total number of individuals living in heavily or lightly populated areas. Our analytical approach reveals that strengthening the migration from populous areas contains the infection at the early stage of the epidemic. Moreover, depending on the exponent of the nonlinear diffusion rate, epidemic outbreaks do not always occur in the most populated areas as one might expect.


Subject(s)
Epidemics , Human Migration , Models, Biological , Diffusion , Nonlinear Dynamics , Population Density , Time
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