RESUMEN

Andean ecosystems are characterized by high humidity, mainly from rain and fog events. Because of differences in altitude two Andean ecosystems - sub-Andean forest and Páramo -face different environmental pressures that affect leaf anatomy and cell wall composition and, consequently, species foliar water uptake (FWU) capacity. Here, FWU capacity of eight species in the Melastomataceae was evaluated and found to be related to proportions of cell wall components and aquaporins in the two ecosystems. Cellulose was labelled with Calcofluor white, and aquaporin and pectins were labelled with monoclonal antibodies. There were differences in plant FWU capacity in both ecosystems, with higher FWU capacity in sub-Andean forest species than in Páramo forest species. Cell wall components were positively related to FWU, with increased FWU related to pectin and aquaporin content of the plasma membrane. Differences in water availability in the two analysed environments led to differences in FWU capacity that are associated with leaf anatomical traits and cell wall composition. In these two environments, plants with similar traits are selected to respond to given environmental pressures. Traits that favour FWU in sub-Andean forest species may lead to further advances of these species in this environments.

RESUMEN

Arsenopyrite (FeAsS), the most common arsenic-bearing mineral, is usually found associated with pyrite (FeS2) in gold mining tailings. This work examined the galvanic effect of FeS2 on As release from FeAsS oxidation in circumneutral media under oxygen-depleted and oxygen-saturated conditions. The oxidation experiments were conducted with a flow-through reactor in the absence of FeS2 particles and in the presence of different contents of this sulfide. The results indicated that the permanent, physical contact between FeAsS and FeS2 particles causes an increase in the accumulated As release, mainly under O2-saturated conditions. At 30% wt. FeS2, the increases relatively to FeS2-free conditions were 82% and 117% in O2-depleted and O2-saturated solutions, respectively. At steady-state, the As release rates increased from (4.9 ± 0.5)× 10-4 µmol m-2 s-1 (0% wt. FeS2) to (1.1-1.9)× 10-3 µmol m-2 s-1 (5-30% wt. FeS2) under O2-saturated conditions. Analysis of FeAsS samples after oxidation revealed oxidized particles partially or entirely covered by precipitates with different sizes, shapes and compositions (e.g., As-S-bearing ferrihydrite, elemental sulfur, and As-O phases). A fine (3-4 nm thick) amorphous layer of S-As-bearing ferric oxy-hydroxide was also identified on oxidized FeAsS, with Fe(III) and As(III) species.

RESUMEN

Snake venoms are natural sources of biologically active molecules that are able to act selectively and specifically on different cellular targets, modulating physiological functions. Thus, these mixtures, composed mainly of proteins and peptides, provide ample and challenging opportunities and a diversified molecular architecture to design and develop tools and agents of scientific and therapeutic interest. Among these components, peptides and small proteins play diverse roles in numerous physiological processes, exerting a wide range of pharmacological activities, such as antimicrobial, antihypertensive, analgesic, antitumor, analgesic, among others. The pharmaceutical and cosmetic industries have recognized the huge potential of these privileged frameworks and believe them to be a promising alternative to contemporary drugs. A number of natural or synthetic peptides from snake venoms have already found preclinical or clinical applications for the treatment of pain, hypertension, cardiovascular diseases and aging skin. A well-known example is captopril, whose natural peptide precursor was isolated from Bothrops jararaca snake venom, which is a peptide-based drug that inhibits the angiotensin-converting enzyme, producing an anti-hypertensive effect. The present review looks at the main peptides (natriuretic peptides, bradykinin-potentiating peptides and sarafotoxins) and low mass proteins (crotamine, disintegrins and three-Finger toxins) from snake venoms, as well as synthetic peptides inspired by them, describing their biochemical, structural and physiological features, as well as their applications as research tools and therapeutic agents.

Asunto(s)

Péptidos/química , Venenos de Serpiente/química , Inhibidores de la Enzima Convertidora de Angiotensina/química , Inhibidores de la Enzima Convertidora de Angiotensina/aislamiento & purificación , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Animales , Bothrops/metabolismo , Humanos , Hipertensión/tratamiento farmacológico , Péptidos/aislamiento & purificación , Péptidos/uso terapéutico , Peptidomiméticos/química , Peptidomiméticos/uso terapéutico , Inhibidores de Agregación Plaquetaria/química , Inhibidores de Agregación Plaquetaria/aislamiento & purificación , Inhibidores de Agregación Plaquetaria/uso terapéutico , Trombosis/tratamiento farmacológico

RESUMEN

INTRODUCTION: Little is known about the optimal management of large, mobile, pedunculated left ventricular clots. The management is particularly challenging in patients with advanced heart failure considered for left ventricular assist device implantation, because the clot may cause pump thrombosis. METHODS: We retrospectively reviewed the records of patients with left ventricular thrombi identified by echocardiography, and found three cases with large protruding mobile clots. RESULTS: In this paper, we are presenting three challenging cases where the clots were successfully treated surgically. In two cases, the removal of clot was performed simultaneously with the implantation of ventricular assist devices. In the third case, the patient underwent only thrombectomy. Overall, the early outcomes were good in all three patients, but one subsequently died from unrelated causes. CONCLUSIONS: These clinical cases give evidence for surgical treatment of large mobile clots without systemic embolism, even if ventricular assist device is implanted during the same operation.

RESUMEN

The in vivo pyrogen test is the main toxicological assay used in the quality control of injectable products, especially immunobiologicals. Pharmacopoeias state that, before the main test, a preliminary test must be conducted on all animals, and must follow the same conditions as the main test. The aim of this study was to determine the normal temperature variation in New Zealand white rabbits during restraint and propose a limit value for considering an animal as suitable for testing. Results of the temperature variation in 4,689 rabbits during preliminary tests were obtained from the routine database of the Pharmacology and Toxicology Department of the National Institute of Quality Control in Health (INCQS/FIOCRUZ), Brazil. From these preliminary tests, 3,364 rabbits were considered suitable for testing according to the Brazilian Pharmacopoeia criteria (temperature variation < 0.5 °C). Results showed that about 92 per cent of the rabbits presented a normal individual temperature variation equal to or below 0.30 °C. Animals presenting a temperature variation close to the fever temperature must not be included in the main test, since they can be stressed or sick. Consequently, the temperature variation of 0.30 °C could be adopted by pharmacopoeias as a limit temperature to be considered in the preliminary test to determine which animals can be used in the main rabbit pyrogen test. Animals can be pre-tested until presenting this safe variation, in order to ensure they are healthy and minimise interference in the result.

Asunto(s)

Temperatura Corporal/fisiología , Pirógenos/farmacología , Conejos/fisiología , Animales , Contaminación de Medicamentos , Fiebre/inducido químicamente , Fiebre/fisiopatología , Pirógenos/normas , Control de Calidad , Valores de Referencia , Restricción Física/fisiología

RESUMEN

BACKGROUND: Heart procurement for orthotopic heart transplant (OHT) is limited by the conventional 4 hours of ischemic time (IT). Based on a recent report from our center showing that extended IT from a young donor group is safe, we widened our geographical reach, resulting in almost 40% of our transplants having an IT > 4 hours. METHODS: We retrospectively reviewed records of adult patients who underwent OHT from January 2006 to December 2011. The primary outcome was survival, and secondary outcomes included resource utilization, end-organ dysfunction, and acute cellular rejection. Overall survival was analyzed using Kaplan-Meier curves and log-rank tests. Secondary outcomes were compared with a combination of parametric and nonparametric statistics. RESULTS: A total of 323 patients underwent OHT. There was a significant difference in overall survival between the standard and extended IT groups (85.7% vs 76.4%, P = .03). There were no significant differences between the groups for secondary outcomes except a higher incidence of liver dysfunction in the extended IT group (84.9% vs 73%, P = .01). Further analysis revealed that mortality remains similar if IT is below 4 hours and between 4 and 5 hours, but begins to climb after 5 hours, driving the difference between our standard and extended IT. CONCLUSIONS: Limited donor availability for OHT dictates alternative strategies to enlarge the donor pool. Although there is an overall increasing risk with extended IT beyond 4 hours, it may be possible to safely increase the threshold to at least 5 hours without compromising the outcomes.

Asunto(s)

Isquemia Fría , Selección de Donante , Trasplante de Corazón , Donantes de Tejidos/provisión & distribución , Enfermedad Aguda , Adulto , Factores de Edad , Anciano , Aloinjertos , Isquemia Fría/efectos adversos , Isquemia Fría/mortalidad , Femenino , Florida/epidemiología , Rechazo de Injerto/epidemiología , Supervivencia de Injerto , Trasplante de Corazón/efectos adversos , Trasplante de Corazón/mortalidad , Humanos , Incidencia , Estimación de Kaplan-Meier , Modelos Lineales , Hepatopatías/epidemiología , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Obtención de Tejidos y Órganos , Transportes , Resultado del Tratamiento

RESUMEN

AIM: To assess the ex vivo effectiveness of the alternated use of 1% NaOCl and 15% citric acid in association with two instrumentation techniques for the disinfection of root canals infected with Enterococcus faecalis and Candida albicans. METHODOLOGY: Eighty human mandibular premolars with straight, oval root canals standardized to 15 mm in length were infected with a mixed culture of E. faecalis and C. albicans for 28 days. Five other teeth were used as controls and were neither contaminated nor instrumented. Specimens were divided into two groups (n = 40), according to whether the canal preparation technique used manual (K-type) or rotary (Protaper Universal) instruments. These groups were further divided into four subgroups (n = 10) according to the irrigation solution used: saline, 1% NaOCl, 1% NaOCl with alternated use of 15% citric acid and 5.25% NaOCl. Root canals were prepared with a crown-down technique until a size 50 K-file or with rotary preparation until an F5 instrument. Microbiological sampling was performed before (S1) and after (S2) the chemomechanical preparation, using sterile paper points. The specimens were split, and 0.02 g of dentine chips was collected from the root thirds to verify the presence of microorganisms in root canal walls. RESULTS: Saline and 1% NaOCl were less effective in reducing microorganisms compared with 1% NaOCl with alternated use of 15% citric acid or 5.25% NaOCl alone (P < 0.05). Both manual and rotary preparations significantly reduced microorganisms regardless of the irrigation solution used (P < 0.05). However, there was no significant difference between the canal preparation techniques (P > 0.05). CONCLUSIONS: Irrigation with 5.25% NaOCl and 1% NaOCl alternated with 15% citric acid reduced microorganisms in infected root canals significantly more than saline and 1% NaOCl.

Asunto(s)

Candida albicans/efectos de los fármacos , Cavidad Pulpar/microbiología , Enterococcus faecalis/efectos de los fármacos , Irrigantes del Conducto Radicular/uso terapéutico , Preparación del Conducto Radicular/métodos , Diente Premolar/microbiología , Ácido Cítrico/uso terapéutico , Dentina/microbiología , Desinfección/métodos , Diseño de Equipo , Humanos , Preparación del Conducto Radicular/instrumentación , Cloruro de Sodio , Hipoclorito de Sodio/uso terapéutico , Ápice del Diente/microbiología

RESUMEN

AIM: To evaluate the use of pulse oximetry as a test for pulp vitality, by comparing in the same patient, the levels of oxygen saturation of the index finger and of the maxillary central incisor and canine teeth without clinically detectable pulp inflammation. METHODOLOGY: Seventeen male and female patients aged between 26 and 38 years participated and a total of 32 maxillary central incisor and 32 canine teeth were analysed. Selection criteria required the teeth to have healthy crowns, or with restorations no more than 2 mm in diameter and no clinical and radiographical signs or symptoms of pulp or periapical inflammatory changes. The negative control group consisted of 10 root filled teeth. Measurements were first taken from the index finger of patients. Their teeth were then subjected to a thermal test with refrigerant gas and then to a vitality test with pulse oximetry. Data were analysed by Pearson's and paired t-tests. RESULTS: There were no significant statistical correlations between blood oxygen levels in the index finger and in the teeth of the patient (P > 0.05). There was a statistically significant difference in the oxygen levels between the two tooth groups studied and the index finger (P

Asunto(s)

Prueba de la Pulpa Dental/métodos , Pulpa Dental/irrigación sanguínea , Oximetría , Adulto , Diente Canino , Femenino , Humanos , Incisivo , Masculino , Maxilar

RESUMEN

We report a case of human monensin intoxication; to our knowledge, this is the first reported case in the medical literature. The patient took a dose of monensin three times higher than a dose considered lethal for cattle and developed a clinical picture similar to that reported in veterinary medicine. There was an early and extremely severe rhabdomyolysis followed by acute renal failure, heart failure, and death. The main changes observed at autopsy were extensive skeletal muscle necrosis, complement deposition at the myocardial level, pulmonary edema, and acute tubular damage.

Asunto(s)

Lesión Renal Aguda/inducido químicamente , Ionóforos/efectos adversos , Monensina/efectos adversos , Rabdomiólisis/inducido químicamente , Lesión Renal Aguda/patología , Adolescente , Complemento C9/análisis , Resultado Fatal , Humanos , Inmunohistoquímica , Riñón/química , Riñón/efectos de los fármacos , Riñón/patología , Masculino , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/patología , Miocardio/química , Miocardio/patología , Mioglobina/análisis , Rabdomiólisis/patología

RESUMEN

Interest in reconstructive surgery for ischemic cardiomyopathy has increased. We prospectively studied patients undergoing left ventricular reconstruction for ischemic cardiomyopathy. This report describes our technique for no-patch repair of left anterior descending aneurysms or akinetic areas. Patients are selected for surgery with discreet left anterior descending scar, usually detected by preoperative magnetic resonance imaging scan and three-dimensional echocardiography, with compensated heart failure or other indications for surgery such as severe coronary artery disease or mitral regurgitation.

Asunto(s)

Cardiomiopatías/cirugía , Aneurisma Coronario/cirugía , Infarto del Miocardio/cirugía , Técnicas de Sutura , Disfunción Ventricular Izquierda/cirugía , Cicatriz/cirugía , Ventrículos Cardíacos/cirugía , Humanos

RESUMEN

The relationship between concentrations of ALA-U and Pb-S for two groups of workers is reported. The first group consisted of workers from a telephone company, and the second, of workers from battery factories with average Pb-S equivalent to 17.3 (g/dl (6.2-39.4) and 61.5 (g/dl (41.1-91.0), respectively. The aim of this study was to evaluate the utilization of ALA-U levels as a screening test for different levels of lead in blood by means of High Performance Liquid Chromatography (HPLC) and of spectrophotometry. A significant correlation was found between measured ALA and levels of blood lead (R = 0.739 - first group; R = 0.902 - second group; p < 0.001). The validity of ALA-U test to evaluate different levels of lead in blood was also studied. By using ALA levels of 3mg/g creatinine as a threshold to detect levels of lead in blood equal to or higher than 20 (g/dl, the test results, for the workers in the first group, showed sensibility of 92% and specificity of 90%. In both groups, the false positives as well the false negatives were lower than 10% which was enough to validate the test.

Asunto(s)

Ácido Aminolevulínico/orina , Intoxicación por Plomo/orina , Enfermedades Profesionales/orina , Adulto , Brasil , Cromatografía Líquida de Alta Presión , Humanos , Intoxicación por Plomo/sangre , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Enfermedades Profesionales/sangre , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Espectrofotometría Ultravioleta

RESUMEN

The use of the internal mammary artery (IMA) in coronary artery bypass surgery has increased substantially over the past 20 years, being at present the conduit of choice for most patients. Complications associated with its use occur occasionally and include life-threatening postoperative ischemia or the revascularized myocardium. We reviewed the records of 1,971 consecutive patients who underwent coronary artery bypass grafting over a 5-year period. All operations included an IMA graft to the left anterior descending coronary artery. Twenty-eight of these patients (1.4%) underwent additional placement of a vein graft on the same region as a salvage maneuver for suspected hypoperfusion as a result of IMA failure. All 28 patients showed life-threatening hemodynamic compromise. Twenty-two of the 28 patients (79%) survived. This was the result of immediate surgical correction, which reversed their hemodynamic instability. IMA hypoperfusion was found more frequently in reoperations and in women and diabetic patients. This syndrome is the result of an imbalance between IMA flow and myocardial demand, causing sudden and unexpected myocardial failure. Its detection and expeditious treatment can successfully modify a serious and potentially lethal clinical situation.

Asunto(s)

Circulación Coronaria , Anastomosis Interna Mamario-Coronaria , Isquemia Miocárdica , Complicaciones Posoperatorias , Femenino , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/terapia , Perfusión

RESUMEN

OBJECTIVE: To compare pulmonary function and peripheral organ blood flow in septic pigs receiving high-volume fluid resuscitation or standard-volume fluid resuscitation with similar goals in oxygen delivery. DESIGN: A prospective study comparing 2 groups of septic pigs. SETTING: A university animal research laboratory. SUBJECTS: Eleven septic pigs. INTERVENTIONS: Basal oxygen delivery was increased from 450 to 550 mL/min to at least 600 mL/min by the sixth hour and maintained for 24 hours. From a baseline pulmonary artery occlusion pressure (PAOP) measurement of approximately 6 mm Hg, the high-volume group (n = 5) was treated until a PAOP measurement of 12 mm Hg was reached and the standard-volume group (n = 6) was treated until a PAOP measurement of 8 mm Hg was reached. Blood transfusions and inotropic agents were added as necessary to reach the oxygen delivery goal. RESULTS: The high-volume group had a significantly greater positive fluid balance, greater weight gain, and a higher PAOP but similar intrapulmonary shunt and extravascular lung water as compared with the standard-volume group. CONCLUSION: Resuscitation with large volumes of fluid in early sepsis with a physiological goal of a higher PAOP to augment oxygen delivery did not cause increased pulmonary edema and oxygenation deficit compared with maintenance of lower cardiac filling pressures.

Asunto(s)

Fluidoterapia/métodos , Pulmón/fisiopatología , Sepsis/terapia , Animales , Sepsis/fisiopatología , Porcinos

RESUMEN

Penetrating suprarenal aortic injuries carry high mortality rates. Difficulties in surgical exposure and bleeding control in this area add to the ominous prognosis. In rare occasions, synchronous injury to the adjacent upper part of stomach may lead to an acute aortogastric fistula, resulting in aortic bleeding into the stomach instead of the peritoneal cavity. Filling of the stomach with blood may temporarily tamponade the aortic perforation. Distortion of this delicate communication during dissection before proximal and distal vascular control is achieved could result in catastrophic hemorrhage. Therefore, recognition of the importance of a fully distended stomach at the suspicion of aortic injury is essential in directing a particular surgical strategy that aims to achieve an unrestricted operative exposure and successful bleeding control.

Asunto(s)

Aorta/lesiones , Enfermedades de la Aorta/cirugía , Fístula/cirugía , Fístula Gástrica/cirugía , Heridas por Arma de Fuego/complicaciones , Enfermedad Aguda , Adolescente , Enfermedades de la Aorta/diagnóstico , Enfermedades de la Aorta/etiología , Resultado Fatal , Fístula/diagnóstico , Fístula/etiología , Fístula Gástrica/diagnóstico , Fístula Gástrica/etiología , Humanos , Masculino , Pronóstico

RESUMEN

The dissemination of Paracoccidioides brasiliensis cells to the heart, omentum/pancreas, spleen, liver and lungs, assessed by colony forming unit (CFU) counts, the levels of specific antibodies to this fungal agent (by ELISA), and the specific DTH reaction were studied in susceptible (B10.A) and resistant (A/Sn) mice. The animals were infected intraperitoneally with P. brasiliensis yeast cells and were evaluated 2, 4, 12 and 16 weeks later. The most remarkable differences between the two mouse strains were observed 16 weeks after infection, when B10.A mice displayed high numbers of CFU in all examined organs, except the heart, high antibody titres, and depressed DTH response. At this point, A/Sn mice presented low or absent CFU in all organs, low antibody titres and expressive DTH response. The CFU counts were shown to be a reliable parameter to discriminate susceptible from resistant animals. The fungal load in the most affected organs correlated with the antibody titres and was inversely correlated with the intensity of the DTH reaction. The patterns of immune response in this model mimic human paracoccidioidomycosis, in which high specific antibody levels and depressed DTH reactions are found in multifocal and severe forms of the disease.

Asunto(s)

Anticuerpos Antifúngicos/sangre , Paracoccidioides/inmunología , Paracoccidioidomicosis/inmunología , Animales , Recuento de Colonia Microbiana , Hipersensibilidad Tardía , Inmunidad Celular , Masculino , Ratones , Paracoccidioides/crecimiento & desarrollo , Paracoccidioidomicosis/microbiología

Asunto(s)

Actitud Frente a la Salud , Internamiento Obligatorio del Enfermo Mental , Psiquiatría Forense , Trastornos Mentales/psicología , Control Social Formal , California , Derechos Civiles , Toma de Decisiones , Hospitalización , Humanos , Estudios Retrospectivos