Quorum sensing (QS) is a communication mechanism between bacteria that allows specific processes to be controlled, such as biofilm formation, virulence factor expression, production of secondary metabolites and stress adaptation mechanisms such as bacterial competition systems including secretion systems (SS). These SS have an important role in bacterial communication. SS are ubiquitous; they are present in both Gram-negative and Gram-positive bacteria and in
Mycobacterium
sp. To date, 8 types of SS have been described (T1SS, T2SS, T3SS, T4SS, T5SS, T6SS, T7SS, and T9SS). They have global functions such as the transport of proteases, lipases, adhesins, heme-binding proteins, and amidases, and specific functions such as the synthesis of proteins in host cells, adaptation to the environment, the secretion of effectors to establish an infectious niche, transfer, absorption and release of DNA, translocation of effector proteins or DNA and autotransporter secretion. All of these functions can contribute to virulence and pathogenesis. In this review, we describe the known types of SS and discuss the ones that have been shown to be regulated by QS. Due to the large amount of information about this topic in some pathogens, we focus mainly on
Pseudomonas aeruginosa
and
Vibrio
spp.
Patients with severe hospital-acquired pneumonia admitted to the ICU present high mortality. The presence of septic shock and chronic obstructive pulmonary disease in conjunction with specific microorganisms are associated with a poor prognosis. Local epidemiological data combined with a patient-based approach may allow a more accurate therapy decision making.
Melkersson proposed leptin dysregulation as a factor in the olanzapine-induced metabolic dysfunction. Their suggestion was based on the absence of the expected positive correlation between serum leptin levels and the BMI, and the loss of the sex-dependent difference in leptin levels, which are higher in women. Although subsequent studies did not confirm that proposal, few of them assessed basal leptin levels and corrected for body fat percentage. Along with these variables, we added a precise definition of participants out of the expected positive correlation in a large sample of schizophrenia patients. Sixty patients (26 women and 34 men) with severe schizophrenia undergoing chronic hospitalization and conventional antipsychotic treatment were switched to olanzapine (10-20 mg/day). We assessed at baseline, and at weeks 8 and 16 of treatment, the percentage of participants with abnormal correlation (out of the 95% confidence interval in the regression line) between leptin levels and the BMI, and the correlation between leptin and insulin, glucose, the insulin resistance index, c-reactive protein (CRP) and treatment response. Leptin levels were higher in women than in men (P<0.01). The positive correlation between leptin levels, BMI and percentage of fat were preserved. After olanzapine, 3.8% of women and 2.9-5.8% of men were out the 95% confidence interval, and the proportion was similar at baseline. Glucose, insulin, the insulin resistance index and the CRP levels significantly increased after olanzapine. The impact of olanzapine on leptin regulation appears discrete and limited to a small number of participants. Additional studies must clarify the features that render them to metabolic dysregulation.
Abstract. Peñ a R, Lahoz C, Mostaza JM, Jiménez J, Subirats E, Pintó X, Taboada M, López-Pastor A, The RAP study group (Hospital Carlos III; Instituto de Salud Carlos III, Madrid; Hospital de Puigcerdá, Gerona; Hospital de Bellvitge, Barcelona; Centro de Salud de Fuencarral; Hospital La Paz, Madrid, Spain). Effect of apoE genotype on the hypolipidaemic response to pravastatin in an outpatient setting. J Intern Med 2002; 251: 518-525.Background. Considerable variability exists in the plasma lipid and lipoprotein response to statin treatment due, in part, to genetic factors. The gene for apolipoprotein E (ApoE) is polymorphic and the different genotypes modulate baseline lipid levels. The objective of the present study was to evaluate the effect of the apoE genotype on the lipoprotein response to pravastatin treatment in an outpatient population followed-up in several different clinics across Spain. Subjects and methods. Subjects (n ¼ 401; 56% female; mean age 57 years), who were hypercholesterolaemic despite a diet poor in saturated fat and
In patients with severe head trauma and ALI receiving mechanical ventilation, expiratory tracheal gas insufflation allowed the targeted arterial PCO(2) level to be maintained together with a substantial reduction in tidal volume.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.