Generation of Monodisperse Protein Nanoparticles by Electrospray Drying

The feasibility of producing relatively monodisperse and biologically active protein particles by electrospray drying is demonstrated. The process entails dissolving dry powder in an electrosprayable solution. The solution is then dispersed and, after solvent evaporation, dry residues can be collected on suitable deposition substrates. The process was demonstrated in the case of insulin. Particles were sized visually, using a scanning electron microscope (SEM), and aerodynamically, using an inertial impactor. When electrosprays of nearly saturated solutions were operated in the stable cone-jet mode, impactor data showed that the particle average aerodynamic diameter ranged from about 88 to 110 nm in diameter and the distributions were quasi-monodisperse with relative standard deviation estimated at approximately 10%. SEM observations for the same conditions showed average particle dimensions ranging from 98 to 117 nm, with predominantly doughnut shapes. Smaller particles can be generated by decreasing the insulin concentration and/or by spraying smaller liquid flow rates. The biological activity of the electrospray-processed insulin samples was confirmed by comparing binding properties on insulin receptors against a control sample. Although the maximum production rate for monodisperse insulin nanoparticles from a single cone-jet is low, at about 0.23 mg/hour, overall production can be increased by multiplexing the device with microfabrication techniques.

Time budgets of lactating dairy cattle in commercial freestall herds

The aim of this study was to examine the time budgets of 205 lactating dairy cows housed in 16 freestall barns in Wisconsin and to determine the relationships between components of the time budget and herd- and cow-level fixed effects using mixed models. Using continuous video surveillance, time lying in the stall, time standing in the stall, time standing in the alleys (including drinking), time feeding, and time milking (time out of the pen for milking and transit) during a 24-h period were measured for each cow. In addition, the number of lying bouts and the mean duration of each lying bout per 24-h period were determined. Time milking varied between cows from 0.5 to 6.0 h/d, with a mean ± standard deviation of 2.7 ± 1.1h/d. Time milking was influenced significantly by pen stocking density, and time milking negatively affected time feeding, time lying, and time in the alley, but not time standing in the stall. Locomotion score, either directly or through an interaction with stall base type (a rubber crumb-filled mattress, MAT, or sand bedding, SAND), influenced pen activity. Lame cows spent less time feeding, less time in the alleys, and more time standing in the stalls in MAT herds, but not in SAND herds. The effect of lameness on lying time is complex and dependent on the time available for rest and differences in resting behavior observed between cows in MAT and SAND herds. In MAT herds, rest was characterized by a larger number of lying bouts of shorter duration than in SAND herds (mean = 14.4; confidence interval, CI: 12.4 to 16.5 vs. mean = 10.2; CI: 8.2 to 12.2 bouts per d, and mean = 1.0; CI: 0.9 to 1.1 vs. mean = 1.3, CI: 1.2 to 1.4h bout duration for MAT and SAND herds, respectively). Lameness was associated with an increase in time standing in the stall and a reduction in the mean (CI) number of lying bouts per day from 13.2 (CI: 12.3 to 14.1) bouts/d for nonlame cows to 10.9 (CI: 9.30 to 12.8) bouts/d for moderately lame cows, and an overall reduction in lying time in MAT herds compared with SAND herds (11.5; CI: 10.0 to 13.0 vs. 12.7; CI: 11.0 to 14.3h/d, respectively). These results show that time out of the pen milking, stall base type, and lameness significantly affect time budgets of cows housed in freestall facilities.

Sub-maximal and maximal Yo-Yo intermittent endurance test level 2: heart rate response, reproducibility and application to elite soccer

The aims of this study were to (1) determine the reproducibility of sub-maximal and maximal versions of the Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2 test), (2) assess the relationship between the Yo-Yo IE2 test and match performance and (3) quantify the sensitivity of the Yo-Yo IE2 test to detect test-retest changes and discriminate between performance for different playing standards and positions in elite soccer. Elite (n = 148) and sub-elite male (n = 14) soccer players carried out the Yo-Yo IE2 test on several occasions over consecutive seasons. Test-retest coefficient of variation (CV) in Yo-Yo IE2 test performance and heart rate after 6 min were 3.9% (n = 37) and 1.4% (n = 32), respectively. Elite male senior and youth U19 players Yo-Yo IE2 performances were better (P < 0.01) than elite youth U16s and sub-elite players (2,603 ± 451 and 2,534 ± 549 vs. 1,855 ± 535 vs. 1,749 ± 382 m). The intra- and inter-season CV for Yo-Yo IE2 test performance were 4.2 and 5.6%, respectively. A correlation was observed (P < 0.05) between Yo-Yo IE2 test performance and the total (r = 0.74) and high-intensity (r = 0.58) running distance covered in a match. A correlation was also evident (P < 0.01) between Yo-Yo IE2 test heart rate after 6 min expressed in percentage of maximal heart rate and the peak values for high-intensity running performed by midfielders in 5-min (r = -0.71), 15-min (r = -0.75) and 45-min periods (r = -0.77). The present data demonstrate that the Yo-Yo IE2 test is reproducible and can be used to determine the capacity of elite soccer players to perform intense intermittent exercise. Furthermore, the Yo-Yo IE2 test was shown to be a sensitive tool that not only relates to match performance but can also differentiate between intermittent exercise performance of players in various standards, stages of the season and playing positions.

HIV/AIDS: perceptions of the Grenadian faith-based community

OBJECTIVE

This exploratory study conducted in 2008 aimed at gathering the views and opinions of leaders of the faith-based community (FBC) in Grenada about the increased incidence of HIV/AIDS in the Caribbean region including their beliefs and attitudes towards persons living with HIV/AIDS (PLHIV/AIDS).

DESIGN AND METHODS

The study followed a cross-sectional design and used a qualitative approach. Telephone surveys were conducted with all faith-based organizations and semi-structured interviews done with key leaders representing the faith-based community in Grenada.

RESULTS

Findings showed that perceptions of HIV/AIDS are embedded in a socio-political-cultural context where many risk behaviours and factors intertwine in complex ways. Religious beliefs are based on love, compassion and acceptance. The most prominent risk behaviours associated with the spread of HIV/AIDS identified by leaders are homosexuality, prostitution, promiscuity and substance abuse which are in direct contradiction to their beliefs and teachings. Leaders felt that these risk behaviours were exacerbated by changes in family structure and the absence of a common moral discourse shared by all sectors of society.

CONCLUSION

The faith-based community has a significant presence across Grenada and it can be an effective partner in helping communities understand and prevent HIV/AIDS and overcome the stigma and discrimination associated with this disease. Training and effective strategies are needed to engage them in the national response to HIV/AIDS without threatening their ideologies and practices.

Production of biomass and beta-D-galactosidase by Candida pseudotropicalis grown in continuous culture on whey

The production of biomass and beta-D-galactosidase by the lactose-utilizing yeast Candida pseudotropicalis NCYC 744 in whey medium was studied. Apparent optimization of growth conditions and medium was done in continuous culture. Optimal pH and temperature were 2.6 and 36-38 degrees C, respectively, Limitations in Cu, Zn, and possibly Mn were detected in deproteinized whey medium. Additions of tryptophan stimulated growth of the yeast. Under optimal conditions in medium supplemented with excess tryptophan, Cu, Zn, and Mn the maximum values obtained: yeast concentration, 4.6 g/L; yeast productivity, 1.4 g/L h (at D = 0.35 h(-1)); enzyme volumetric productivity, 2100 U/L h (at D = 0.25 h(-1)); maintenance coefficient, 5-10 mg lactose/g cell h; saturation constant (K(s)) for lactose, 4.76mM; maximum specific growth rate, (mu(max)), 0.47 h(-1). No significant increase in specific enzyme activity (U/mg cell) was observed after medium optimization evidencing the importance of regulatory controls in enzyme synthesis.

The centrality of community dynamics in the socio-economic recovery of devastated communities

OBJECTIVE

To assess and explore the health and socio-economic outcomes of Jubilee, a community on the Caribbean island of Grenada hit by Hurricane Ivan in 2004 and to identify remaining barriers to recovery.

METHODS

The assessment consisted of a mixed methods approach employing observations, household surveys, in-depth interviews and focus groups.

RESULTS

Eighty-five per cent of the residents live in a single-family home type dwelling which is occupied by multiple families. Twenty-seven per cent of the respondents depended on a river or stream for water and 83% utilized an outdoor pit latrine. Construction accounted for 28% of the employment while 16% reported having no occupation. Public and private transportation was limited and 48% of the residents lived on less than one United States of America (US) dollar per day. Access to healthcare was reported by 89% and the prevalence of diabetes and hypertension was identified by 13% and 30% of the residents respectively. Social fragmentation within the community represents a barrier that keeps the community from developing common goals leading to full economic recovery.

CONCLUSION

Jubilee has not fully recovered from the effects of Hurricane Ivan, but progress has been made in the reconstruction effort. These efforts have addressed the most immediate and basic needs of the community, mainly utility service infrastructure and home repairs. However issues related to the community's economic recovery are still unresolved.

MPTP administration increases plasma levels of acute phase proteins in non-human primates (Macaca fascicularis)

Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons in the Substantia Nigra pars compacta (SNpc). Parkinsonian patients and animal models of PD show inflammatory phenomena such as microglial activation and cytokine production that could modulate the progression of the disease, since they play a crucial role in the degenerative process. Since acute phase proteins (APPs) are involved in a number of homeostatic alterations and inflammatory processes, we analyzed the levels of APPs in primates before and after treatment with MPTP. A significant increase in C-reactive protein (CRP), serum amyloid A (SAA) and haptoglobin (HP) levels after MPTP treatment. These results demonstrate that MPTP induces a systemic generalized inflammatory reaction after specific dopaminergic neurotoxicity insult, suggesting that the inflammatory process in Parkinsonism may affect other immune-inflammatory responses outside the brain.

Randomised controlled trial in non-invasive ventilation: what trial?

Amyotrophic lateral sclerosis (ALS) is caused by mutations in the gene for Cu/Zn superoxide dismutase (SOD1) in 10% of familial and sporadic cases. During the SOD1 analysis of 9 FALS and 121 SALS, in only one sporadic case we found the exonic mutation N19S; in 15 SALS patients we found a 319t>a variation in IVS1 sequence, at 108 bp upstream from exon 2. This variation has an unusually high frequency of 11% and is always in linkage disequilibrium with a described polymorphism in IVS3, +34a>c. The 319t>a variation is classified in two different public databases, HGMD and The ALS Online Database, as a splicing mutation and not as a polymorphism. The unusually high frequency of this mutation in our patients prompted us to determinate its frequency in 130 age- and gender- matched healthy controls and in 54 patients with Alzheimer's disease. We found again linkage disequilibrium with the polymorphism in intron 3, and the frequency of 11% and 7.8%, respectively. These results strongly support the idea that the IVS1 +319 t>a alone is not an ALS causing mutation, and that special care must be taken in the interpretation of data from mutations databases for correct genetic counselling.

Analysis of pharmacogenetic biomarkers in rectal patients trated with chemoradiotherapy

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Background: 5FU-based chemoradiotherapy before total mesorectal excision (TME) is currently the gold standard treatment for stage II and III rectal cancer patients. Pathological complete response (pCR) is related with a longer survival. We have used known predictive pharmacogenetics biomarkers to identify in our series responders and non responders to preoperative RQ. Methods: 77 stage II/III rectal patients were genotyped using direct sequencing (TS VNTR) and SNAPshot (DPYD, EGFR) techniques. DNA was obtained from peripheral blood samples. We have studied Thymidylate synthetase (TS VNTR; high expression haplotypes: TSER 2R/3R, 3C/3G, 3G/3G and low expression: TSER 2R/2R, 2R/3C, 3C/3C; TS 1494del6: associated to a better efficay of 5Fu), dihydropyrimidine dehydrogenase (DPYD; DPYD*2 associated to worse toxicity), EGFR (CA repeats in intron 1: 16/16 associated to worse efficacy) polymorphisms. Median age of our study cohort was 65 years old (37–85). There were 24 female and 53 male patients. All of them were Caucasian. 21 patients (27.3%) had stage II and 56 (72.7%) stage III. They were staged by TC, colonoscopy and endorectal ultrasonography. The patients received 5fu 325 mg/m2/day continuous infusion along the hyperfractionated accelerated radiotherapy schedule (50,4 Gy). All were submitted to TME. Outcomes after surgery are measured by tumour regression grade (from TRG1= complete pathological response, to TRG5=no regression). Data were studied by univariate and multivariate analysis. Results: The sample was in Hardy-Weinberg equilibrium for all polymorphisms, irrespectively of the response status. 50 patients (64.9%) and 27 (35.1%) had low and high expression genotype for TS respectively. pCR (TRG1) was obtained in 24 patients (31,6%) and microscopic foci (TRG2) in 14 (18,2%), TRG 3–4 in 38 (49,3%), and 1 patient had no response (TRG5). We haven’t found a statistically significant relationship between TRG1 and TS status, or any other biomarker studied. There's no relationship also with initial clinical stage. Conclusions: Biomarkers EGFR (intron 1 CA repeats), TS (TS 1494del6, TS VNTR) and DPYD in blood samples, are not good enough to predict response to RQ in rectal cancer.

No significant financial relationships to disclose.