238 resultados para 11 Medical and Health Sciences
Resumo:
We have investigated the lipid polylysine core peptide (LCP) system as a self-adjuvanting group A streptococcal (GAS) vaccine delivery approach. LCP constructs were synthesised incorporating peptides from the M protein conserved carboxy terminal C-repeat region, the amino terminal type-specific region and from both of these regions. Immunisation with the constructs without adjuvant led to the induction of peptide-specific serum IgG antibody responses, heterologous opsonic antibodies, and complete protection from GAS infection. These data indicate that protective immunity to GAS infection can be evoked using the self-adjuvanting LCP system, and point to the potential application of this system in human mucosal GAS vaccine development. (c) 2005 Elsevier Ltd. All rights reserved.
Resumo:
Objectives: Obesity is a disease with excess body fat where health is adversely affected. Therefore it is prudent to make the diagnosis of obesity based on the measure of percentage body fat. Body composition of a group of Australian children of Sri Lankan origin were studied to evaluate the applicability of some bedside techniques in the measurement of percentage body fat. Methods: Height (H) and weight (W) was measured and BMI (W/H-2) calculated. Bioelectrical impedance analysis (BIA) was measured using tetra polar technique with an 800 mu A current of 50 Hz frequency. Total body water was used as a reference method and was determined by deuterium dilution and fat free mass and hence fat mass (FM) derived using age and gender specific constants. Percentage FM was estimated using four predictive equations, which used BIA and anthropometric measurements. Results: Twenty-seven boys and 15 girls were studied with mean ages being 9.1 years and 9.6 years, respectively. Girls had a significantly higher FM compared to boys. The mean percentage FM of boys (22.9 +/- 8.7%) was higher than the limit for obesity and for girls (29.0 +/- 6.0%) it was just below the cut-off. BMI was comparatively low. All but BIA equation in boys under estimated the percentage FM. The impedance index and weight showed a strong association with total body water (r(2)= 0.96, P < 0.001). Except for BIA in boys all other techniques under diagnosed obesity. Conclusions: Sri Lankan Australian children appear to have a high percentage of fat with a low BMI and some of the available indirect techniques are not helpful in the assessment of body composition. Therefore ethnic and/or population specific predictive equations have to be developed for the assessment of body composition, especially in a multicultural society using indirect methods such as BIA or anthropometry.
Resumo:
NF-kappaB activation is associatied with the inflammation of bone destruction and certain cancers. The NEMO (NF-kB essential modulator)-binding domain (NBD) protein inhibits the activation of NF-kappaB. Cellular studies have shown that the NBD protein inhibits osteoclastogenesis. Mimicking infection with a lipopolysaccharide injection in mice resulted in activated osteoclasts and reduced bone mineral density. These responses are inhibited with the NBD peptide. In a mouse model of rheumatoid arthritis, collagen-induced arthritis, treatment with the NBD protein delayed the onset, lowered the incidence and decreased the severity of the arthritis. NF-kappaB is a target in the inflammation associated with bone destruction. A key issue is whether or not this important transcription factor can be inhibited without causing excessive adverse effects and/or toxicity.
Resumo:
We have used an animal model to test the reliability of a new portable continuous-wave Doppler ultrasonic cardiac output monitor, the USCOM. In six anesthetized dogs, cardiac output was measured with a high-precision transit time ultrasonic flowprobe placed on the ascending aorta. The dogs' cardiac output was increased with a dopamine infusion (0-15 mug (.) kg(-1) (.) min(-1)). Simultaneous flowprobe and USCOM cardiac output measurements were made. Up to 64 pairs of readings were collected from each dog. Data were compared by using the Bland and Altman plot method and Lin's concordance correlation coefficient. A total of 319 sets of paired readings were collected. The mean (+/-SD) cardiac output was 2.62 +/- 1.04 L/min, and readings ranged from 0.79 to 5.73 L/min. The mean bias between the 2 sets of readings was -0.01 L/min, with limits of agreement (95% confidence intervals) of -0.34 to 0.31 L/min. This represents a 13% error. In five of six dogs, there was a high degree of concordance, or agreement, between the 2 methods, with coefficients >0.9. The USCOM provided reliable measurements of cardiac output over a wide range of values. Clinical trials are needed to validate the device in humans.
Resumo:
The BCR-ABL tyrosine kinase inhibitor imatinib has greatly improved the outcome for patients with chronic myeloid leukaemia (CML). Unfortunately, mutations causing resistance to imatinib are leading to relapses in some patients. In addition to inhibiting the wild-type BCR-ABL, BMS-354825 inhibited 14 of 15 BCR-ABL mutants. BMS-354825 treatment of immunodeficient mice prevented the progression of the disease in mice treated with the most clinical common imatinib-resistant mutant Met351Thr. The safety and efficacy of BMS-354825 is presently being evaluated in a phase I/II clinical trial in CML patients with imatinib resistance. The frequency of clinical use of SMS-3548125 in CML patients will depend on its efficacy/safety profile in clinical trial.
Resumo:
We have previously constructed an acapsular Pasteurella multocida X-73 (serogroup A) mutant strain which was attenuated in virulence for chickens (Chung JY, Wilkie IW, Boyce JD, Townsend KM, Frost AJ, Ghodussi M, Adler B. Role of capsule in the pathogenesis of fowl cholera caused by Pasteurella multocida serogroup A. Infect. Immun. 2001;69:2487-2492). In this study, we have assessed the ability of this acapsular strain (PBA930) to induce protection against wild-type challenge in mice and the natural host chickens. Intramuscular administration of PBA930 to mice stimulated significant protection against X-73 and the heterologous strain P-1059 (A:3), but not against challenge with P-1662 (A:4). No protection was observed when PBA930 was introduced by the intraperitoneal or subcutaneous routes in mice. Significantly, the acapsular strain PBA930 was able to induce protection against challenge with wild type X-73 in chickens. (c) 2004 Elsevier Ltd. All rights reserved.
Resumo:
Oxidative metabolism of bilirubin (BR) - a breakdown product of haem with cytoprotective and toxic properties - is an important route of detoxification in addition to glucuronidation. The major enzyme(s) involved in this oxidative degradation are not known. In this paper, we present evidence for a major role of the hepatic cytochrome P450 2A5 (Cyp2a5) in BR degradation during cadmium intoxication, where the BR levels are elevated following induction of haem oxygenase-1 (HO-1). Treatment of DBA/2J mice with CdCl2 induced both the Cyp2a5 and HO-1, and increased the microsomal BR degradation activity. By contrast, the total cytochrome P450 (CYP) content and the expression of Cyp1a2 were down-regulated by the treatment. The induction of the HO-1 and Cyp2a5 was substantial at the mRNA, protein and enzyme activity levels. In each case, the up-regulation of HO-1 preceded that of Cyp2a5 with a 5-10 h interval. BR totally inhibited the microsomal Cyp2a5-dependent coumarin hydroxylase activity, with an IC50 approximately equal to the substrate concentration. The 7-methoxyresorufin 7-O-demethylase (MROD) activity, catalyzed mainly by the Cyp1a2, was inhibited up to 36% by BR. The microsomal BR degradation was inhibited by coumarin and a monoclonal antibody against the Cyp2a5 by about 90%. Furthermore, 7-methoxyresorufin, a substrate for the Cyp1a2, inhibited BR degradation activity by approximately 20%. In sum, the results strongly suggest a major role for Cyp2a5 in the oxidative degradation of BR. Secondly, the coordinated up-regulation of the HO-1 and Cyp2a5 during Cd-mediated injury implicates a network of enzyme systems in the maintenance of balancing BR production and elimination.
Resumo:
The clinical use of potent, well-tolerated, broad-spectrum antibiotics has been paralleled by the development of resistance in bacteria, and the prevalence of highly resistant bacteria in some intensive care units is despairingly commonplace. The intensive care community faces the realistic prospect of untreatable nosocomial infections and should be searching for new approaches to diagnose and manage resistant bacteria. In this review, we discuss some of the relevant underlying biology, with a particular focus on genetic transfer vehicles and the relationship of selection pressure to their movements. It is an attempt to demystify the relevant language and concepts for the anaesthetist and intensivist, to explain some of the reasons for the emergence of resistance in bacteria, and to provide a contextual basis for discussion of management approaches such as selective decontamination and antibiotic cycling.
Resumo:
Objectives: To re-examine interhospital variation in 30 day survival after acute myocardial infarction ( AMI) 10 years on to see whether the appointment of new cardiologists and their involvement in emergency care has improved outcome after AMI. Design: Retrospective cohort study. Setting: Acute hospitals in Scotland. Participants: 61 484 patients with a first AMI over two time periods: 1988 - 1991; and 1998 - 2001. Main outcome measures: 30 day survival. Results: Between 1988 and 1991, median 30 day survival was 79.2% ( interhospital range 72.1 - 85.1%). The difference between highest and lowest was 13.0 percentage points ( age and sex adjusted, 12.1 percentage points). Between 1998 and 2001, median survival rose to 81.6% ( and range decreased to 78.0 - 85.6%) with a difference of 7.6 ( adjusted 8.8) percentage points. Admission hospital was an independent predictor of outcome at 30 days during the two time periods ( p< 0.001). Over the period 1988 - 1991, the odds ratio for death ranged, between hospitals, from 0.71 ( 95% confidence interval ( CI) 0.58 to 0.88) to 1.50 ( 95% CI 1.19 to 1.89) and for the period 1998 - 2001 from 0.82 ( 95% CI 0.60 to 1.13) to 1.46 ( 95% CI 1.07 to 1.99). The adjusted risk of death was significantly higher than average in nine of 26 hospitals between 1988 and 1991 but in only two hospitals between 1998 and 2001. Conclusions: The average 30 day case fatality rate after admission with an AMI has fallen substantially over the past 10 years in Scotland. Between-hospital variation is also considerably less notable because of better survival in the previously poorly performing hospitals. This suggests that the greater involvement of cardiologists in the management of AMI has paid dividends.