Zein nanoparticles containing ceftazidime and tobramycin: antibacterial activity against Gram-negative bacteria

Aims: This work describes the encapsulation of ceftazidime and tobramycin in zein nanoparticles (ZNPs) and the characterization of their antibacterial and antibiofilm activities against Gram-negative bacteria. Materials & methods: ZNPs were synthesized by nanoprecipitation. Cytotoxicity was assessed by MTT assay and antibacterial and antibiofilm assays were performed by broth microdilution and violet crystal techniques. Results: ZNPs containing ceftazidime (CAZ-ZNPs) and tobramycin (TOB-ZNPs) showed drug encapsulation and thermal stability. Encapsulation of the drugs reduced their cytotoxicity 9-25-fold. Antibacterial activity, inhibition and eradication of biofilm by CAZ-ZNPs and TOB-ZNPs were observed. There was potentiation when CAZ-ZNPs and TOB-ZNPs were combined. Conclusion: CAZ-ZNPs and TOB-ZNPs present ideal physical characteristics for in vivo studies of antibacterial and antibiofilm activities.

Heme oxygenase/carbon monoxide-biliverdin pathway down regulates neutrophil rolling, adhesion and migration in acute inflammation

BACKGROUND AND PURPOSE

Heme oxygenase (HO) activity is known to down-regulate inflammatory events. Here, we address the role of HO and its metabolites, carbon monoxide (CO) and biliverdin (BVD), in leukocyte rolling, adhesion and neutrophil migration during inflammatory processes.

EXPERIMENTAL APPROACH

Intravital microscopy was used to evaluate leukocyte rolling and adhesion in the mesenteric microcirculation of mice. TNFalpha and IL-1beta were determined by ELISA and HO-1 protein expression by Western blot.

KEY RESULTS

Intraperitoneal challenge with carrageenan enhanced HO-1 protein expression in mesentery and bilirubin concentration in peritoneal exudates. Pretreatment of mice with a non-specific inhibitor of HO (ZnDPBG) or with a HO-1 specific inhibitor (ZnPP IX) enhanced neutrophil migration, rolling and adhesion on endothelium induced by carrageenan. In contrast, HO substrate (hemin), CO donor (DMDC) or BVD reduced these parameters. The reduction of neutrophil recruitment promoted by HO metabolites was independent of the production of chemotactic cytokines. Inhibitory effects of CO, but not of BVD, were counteracted by treatment with a soluble guanylate cyclase (sGC) inhibitor, ODQ. Furthermore, inhibition of HO prevented the inhibitory effect of a nitric oxide (NO) donor (SNAP) upon neutrophil migration, while the blockade of NO synthase (NOS) activity by aminoguanidine did not affect the CO or BVD effects.

CONCLUSIONS AND IMPLICATIONS

Metabolites of HO decreased leukocyte rolling, adhesion and neutrophil migration to the inflammatory site by a mechanism partially dependent on sGC. Moreover, inhibition by NO of neutrophil migration was dependent on HO activity.

The epidemiology of erectile dysfunction and its correlates in men with chronic renal failure on hemodialysis in Londrina, southern Brazil

Erectile dysfunction (ED) is a common condition in aging men, but little is known about the prevalence of ED in some specific groups of patients such as those with end-stage renal disease (ESRD). A cross-sectional study was conducted to determine the prevalence of ED in ESRD patients undergoing hemodialysis in two clinics of Londrina, Brazil. The prevalence and severity of ED were assessed using the International Index of Erectile Function and a single global question. The dependence of ED on independent variables was evaluated by logistic regression. Some degree of ED was found in 86.4% of our sample (n=118). Complete ED was reported by 25.4% of subjects, moderate ED by 35.4%, and minimal ED by 24.6%. Subjects < 50 y old had a prevalence of moderate/complete ED of 52.6%, whereas in men > or = 50 y old, it was 70.5%. Age, diabetes, and low income were significantly associated with ED. Although highly prevalent, only a low percentage of uremic ESRD patients on hemodialysis were being treated for ED. Our data suggest that ED is related to uremia and other comorbid conditions that often accompany ESRD.

Participation of alpha-1 and alpha-2 adrenoceptors of the lateral hypothalamic area in water intake, and renal sodium, potassium and urinary volume excretion induced by central administration of angiotensin II

The circumventricular structures and the lateral hypothalamus (LH) have been shown to be important for the central action of angiotensin II (ANGII) on water and electrolyte regulation. Several anatomical findings have demonstrated neural connection between circumventricular structures and the LH. The present experiments were conducted to investigate the role of the alpha-adrenergic antagonists and agonistic injected into the LH on the water intake, sodium and potassium excretion elicited by injections of ANGII into the lateral ventricle (LV). The water intake was measured every 30 min over a period of 120 min. The sodium, potassium and urinary volume were measured over a period of 120 min in water-loaded rats. The injection of ANGII into the LV increased the water intake, which was reduced by previous injection of clonidine (an alpha-2-adrenergic agonist) into the LH. The injection of yohimbine (an alpha-2-adrenergic antagonist) and prazosin (an alpha-1-adrenergic antagonist) into the LH, which was done before injecting ANGII into the LV, also reduced the water intake induced by ANGII. The injection of ANGII into the LV reduced the sodium, potassium and urinary volume. Previous treatment with clonidine attenuated the action of ANGII in reducing the sodium, potassium and urinary volume, whereas previous treatment with yohimbine attenuated the effects of ANGII but with less intensity than that caused by clonidine. Previous treatment with prazosin increased the inhibitory effects of ANGII in those parameters. The injection of yohimbine and prazosin, which was done before the injection of clonidine, attenuated the effect of clonidine on the ANGII mechanism. The results of this study led us to postulate that when alpha-2-adrenergic receptors are blocked, the clonidine may act on the imidazoline receptors to produce its effects on the ANGII mechanism. We may also conclude that the LH is involved with circumventricular structures, which present excitatory and inhibitory mechanisms. Such mechanisms are responsible for regulating the renal excretion of sodium, potassium and water.

[Nutritional approach in pregnant and nursing adolescents: basic strategy to prevent risks]

OBJECTIVE: To present the different factors that can interfere in the neonatal evolution and results, as well as the approach strategic nutritional aspects in health promotion and attention of pregnant nursing adolescents. METHOD: National and international literature provided with subsidies to discuss and summarize practical and relevant aspects for the clinical assistance of pregnant and nursing adolescents, especially the lower age group. RESULTS: The approach to pregnant adolescents requires evaluation of parameters of clinical, nutritional, and psychosocial risk. Among the very young adolescents, in addition to those parameters, their gynecological age and physical growth stage are also relevant. The nutritional evaluation and the dietary orientation of the pregnant and nursing adolescents constitute support steps in health promotion and attention, preventing risks such as malnutrition, anemia, vitamin deficiency, in addition to low intrauterine growth, low birth weight and postnatal undernourishment. CONCLUSION: The complexity of the factors interfering in the course of precocious pregnancy requires deep knowledge of the problem by the health staff in order to be able to effectively to intervene in more critical and prior aspects of the health support for this risk group.

[Challenges in the approach to adolescents: confidentiality and contraceptive orientation]

OBJECTIVE: The article has the purpose of presenting some questions related to professional ethics and juridical aspects of the approach to sexuality in adolescence, as well as of offering a practical review of the approach and contraceptive methods used by adolescents.METHODS: The bibliographic review encloses national and international literature, as well as juridical orientation in specific questions related to Child and Adolescent Statute and Brazilian Penal Code.RESULTS: Among the aspects of the approach to adolescents, confidentiality is distinguished as one of the most important strategies, mainly when the topic is associated to questions related to sexuality. In Brazil, although adolescents have been contributing in an effective way to the increase in the fecundity rate, there is, legally speaking, a hiatus concerning the guarantee of the rights of adolescents and professionals in exercise of contraceptive practice.CONCLUSIONS: The challenge for the health professionals, particularly the pediatricians who deal with adolescents, is to collaborate on the consolidation of rules which regulate the orientation in reproductive health for adolescents, once Brazilian Penal Code is anachronous concerning the reality of sexual behavior and its possible consequences.

[Traffic accidents in a metropolitan area of southern Brazil--victim and lesion characterization]

Casualties treated in a Emergency Hospital of Porto Alegre, Brazil, during the year 1988, for injuries received as a result of traffic accidents, are described by means of a retrospective study of the data provided by the Documentation and Statistics Sector of the hospital (n = 6.099). The results, similar to those described in the literature, draw special attention to the predominance of the male sex (69.2%), to the concentration of accidents involving individuals of between 20 and 39 years of age, inclusive, (52%) and to the frequency which the head is injured (49.6%) of the patients. Severe injuries such as bruises and fractures were found, respectively, in 61.5% and 24.2% of the patients. The data reveal, further, the large number and the seriousness of the injuries caused by accidents involving pedestrians which accounted for 32.7% of the total number of attendances related to traffic accidents, 57.2% of hospital internments; 54.6% of the victims of this kind of accident were under 9 years of age and 42.8% were over 60.

Microsurgery in severe posterior epistaxis

A brief review of surgery for severe posterior epistaxis has been outlined. Hundred and forty-five (27.3%) patients were treated by transnasal microsurgery in order to undergo ligation of the branches of the sphenopalatine artery in the nasal cavity. The rate of failure was 6.1%. It seems that by using this kind of operation, we can significantly decrease the morbidity in relation to other methods of controlling the posterior epistaxis.