RESUMO
An important characteristic that determines the behavior of a solute in water is whether it is hydrophobic or hydrophilic. The traditional classification is based on chemical experience and heuristics. However, this does not reveal how the local environment modulates this important property. We present a local fingerprint for hydrophobicity and hydrophilicity inspired by the two body contribution to the entropy. This fingerprint is an inexpensive, quantitative, and physically meaningful way of studying hydrophilicity and hydrophobicity that only requires as input the water-solute radial distribution functions. We apply our fingerprint to octanol, benzene, and 20 proteinogenic amino acids. Our measure of hydrophilicity is coherent with chemical experience, and moreover, it also shows how the character of an atom can change as its environment is changed. Finally, we use the fingerprint as a collective variable in a funnel metadynamics simulation of a host-guest system. The fingerprint serves as a desolvation collective variable that enhances transitions between the bound and unbound states.
Assuntos
Interações Hidrofóbicas e Hidrofílicas , Metano/química , Peptídeos/química , Ligação de Hidrogênio , Modelos Moleculares , Conformação Proteica , TermodinâmicaRESUMO
The protective role of trehalose against oxidative stress caused by hydrogen peroxide in Candida albicans has been investigated in the homozygous mutant ntc1Delta/ntc1Delta, disrupted in the NTC1 gene, which encodes the neutral (cytosolic) trehalase (Ntc1p). After a severe oxidative exposure (50 mM H(2)O(2)), both parental (CAI-4) and ntc1Delta/ntc1Delta exponential-phase cells stored large amounts of intracellular trehalose. In turn, the degree of cell survival was roughly equivalent in both strains, although slightly higher in ntc1Delta/ntc1Delta cultures. The mechanism of 'adaptive tolerance' was functional in the two strains. Thus, a gently oxidative pretreatment (5 mM H(2)O(2)) increased the recovery of cellular viability when it was followed by a severe challenge (50 mM H(2)O(2)); this phenomenon was accompanied by a significant elevation of the endogenous trehalose content. Oxidative stress also induced specific activation of the antioxidant enzymes catalase and glutathione reductase upon gentle oxidative treatment (5 mM H(2)O(2)), whereas superoxide dismutase activity was only activated upon prolonged exposure. Taken together, these results strongly suggest that in C. albicans neutral trehalase activity does not play an essential role in the protective response against oxidative stress. They also suggest that a diminished Ntc1p activity might favour the growth of C. albicans cells subjected to a strong oxidative exposure.
Assuntos
Candida albicans/fisiologia , Peróxido de Hidrogênio/farmacologia , Estresse Oxidativo , Trealase/metabolismo , Candida albicans/efeitos dos fármacos , Candida albicans/enzimologia , Candida albicans/genética , Meios de Cultura , Resposta ao Choque Térmico , Trealase/genética , Trealose/metabolismoRESUMO
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Assuntos
Idoso , Masculino , Humanos , Fatores de Tempo , Síndrome , Apendicectomia , Apendicite , Doença Aguda , Hérnia Femoral , SeguimentosRESUMO
OBJECTIVES: To analyze the quality of several anesthetic techniques used for major outpatient surgery in our hospital, by quantifying for each the relative risk (RR) of adverse events during anesthesia and in the postoperative period. PATIENTS AND METHODS: One thousand seventeen patients who underwent surgery between 18 May 1998 and 23 October 1998 were studied retrospectively. RESULTS: The mean age of the patients was 52.27 +/- 24.65 yr; 44.18% were ASA I, 40.56% were ASA II, 14.56% ASA III and 0.67% ASA IV. Mean time of surgery was 33 +/- 16.49 min and mean recovery time until discharge was 77.3 +/- 93.4 min. Admission was necessary for 0.6% of the patients and re-admission for 0.3%. General anesthesia was used with 19%, anesthetic monitoring with 17%, regional anesthesia (including peribulbar) with 46% and local anesthesia plus sedation with 16.6%. In 95% of the cases, no adverse events occurred during anesthesia; in 94.8% no such events occurred during the early recovery period. During surgery and postoperative recovery, intradural anesthesia was associated with significantly greater RR of adverse events in comparison with general anesthesia (6.6 and 2.2 respectively) and in comparison with monitored anesthesia (7.2 and 3.3). No differences in RR were found between general anesthesia and monitored anesthesia. Problems were slight to moderate in severity and mainly related to nausea and vomiting (2%). CONCLUSIONS: Recording perioperative events permits evaluation of the quality of anesthesic procedures. Intradural anesthesia is associated with more complications.
Assuntos
Procedimentos Cirúrgicos Ambulatórios , Anestesia/efeitos adversos , Anestesia/normas , Complicações Intraoperatórias/etiologia , Complicações Pós-Operatórias/etiologia , Controle de Qualidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , RiscoRESUMO
Objetivos. Analizar la calidad de las diferentes técnicas anestésicas empleadas en la unidad de cirugía mayor ambulatoria (UCMA) de nuestro hospital, cuantificando los riesgos relativos (RR) de sufrir incidencias adversas durante la anestesia y el período postoperatorio en cada una de ellas. Pacientes y métodos. Se estudiaron retrospectivamente 1.017 pacientes intervenidos entre el 18/5/98 y el 23/10/98.Resultados. La edad media fue de 52,27 ñ 24,65 años, con un 44,18 por ciento de ASA 1, un 40,56 por ciento de ASA 2, un 14,57 por ciento de ASA 3 y un 0,67 por ciento de ASA 4. El tiempo quirúrgico medio fue de 33 ñ 16,49 min y el tiempo medio de recuperación hasta el alta fue de 77,30 ñ 93,4 min. Se registró un 0,6 por ciento de ingresos y un 0,3 de reingresos. El 19 por ciento de los pacientes recibieron anestesia general, el 17 por ciento cuidados anestésicos monitorizados, el 46 por ciento anestesia regional, incluyendo la anestesia peribulbar, y el 16,6 por ciento anestesia local más sedación. El 95 por ciento de los pacientes no presentaron incidencias durante la anestesia y en el 94,8 por ciento tampoco en el período de recuperación inmediata. La anestesia intradural presentó un significativo aumento del RR de padecer incidencias adversas frente a la anestesia general (6,6 y 2,2) y respecto a los cuidados anestésicos monitorizados (7,2 y 3,3) en los períodos intraoperatorio y postoperatorio, respectivamente. No se objetivó un incremento de los RR entre la anestesia general y los cuidados anestésicos monitorizados. Los problemas fueron de gravedad leve a moderada, destacando un 2 por ciento de náuseas y vómitos. Conclusiones. El registro de las incidencias perioperatorias permite valorar la calidad de los procedimientos anestésicos. La anestesia intradural es la técnica que se asocia a una mayor morbilidad (AU)
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Assuntos
Pessoa de Meia-Idade , Pré-Escolar , Criança , Adulto , Adolescente , Idoso de 80 Anos ou mais , Idoso , Masculino , Feminino , Humanos , Controle de Qualidade , Procedimentos Cirúrgicos Ambulatórios , Risco , Complicações Pós-Operatórias , Estudos Retrospectivos , Anestesia , Complicações IntraoperatóriasRESUMO
The natural history of colonic diverticulitis rarely includes acute solitary localization in the cecum. Complications are even more rarely seen. We report retrospectively nine cases seen in our unit. There were 5 males and 4 females, mean age 54 years. The patients presented with a more or less painful abdomen with localization in the right iliac region and signs of peritoneal irritation. Physical examination revealed a painful mass in this zone. Fever and hyperleukocytosis were not found in all patients. Barium enema demonstrated signs of pseudocompression of the cecum in four cases suggesting a tumoral formation in two and diverticulitis in the two others. A right hemicolectomy was performed in five patients as peroperative pathological diagnosis could not be ascertained on the macroscopic specimen. Diverticulectomy in the four other patients was unsuccessful in direct relation with the disease course and late diagnosis.