Injectable Hydrogels Based on Pluronic/Water Systems Filled with Alginate Microparticles for Biomedical Applications

A (model) composite system for drug delivery was developed based on a thermoresponsive hydrogel loaded with microparticles. We used Pluronic F127 hydrogel as the continuous phase and alginate microparticles as the dispersed phase of this composite system. It is well known that Pluronic F127 forms a gel when added to water in an appropriate concentration and in a certain temperature range. Pluronic F127 hydrogel may be loaded with drug and injected, in its sol state, to act as a drug delivery system in physiological environment. A rheological characterization allowed the most appropriate concentration of Pluronic F127 (15.5 wt%) and appropriate alginate microparticles contents (5 and 10 wt%) to be determined. Methylene blue (MB) was used as model drug to perform drug release studies in MB loaded Pluronic hydrogel and in MB loaded alginate microparticles/Pluronic hydrogel composite system. The latter showed a significantly slower MB release than the former (10 times), suggesting its potential in the development of dual cargo release systems either for drug delivery or tissue engineering.

Steroid insensitive fixed airflow obstruction is not related to airway inflammation in older non-smokers with asthma

There is limited evidence linking airway inflammation and lung function impairment in older non-smoking asthmatics with fixed airflow obstruction (FAO), which can develop despite treatment with inhaled corticosteroids (ICS). We assessed lung function (spirometry, forced oscillation technique (FOT)), lung elastic recoil and airway inflammation using bronchoalveolar lavage (BAL) in non-smoking adult asthmatics with FAO, following 2 months treatment with high-dose ICS/long-acting beta-agonist. Subjects demonstrated moderate FAO, abnormal FOT indices and loss of lung elastic recoil. This cross-sectional study showed a lack of a relationship between BAL neutrophils, eosinophils, inflammatory cytokines and lung function impairment. Other inflammatory pathways or the effect of inflammation on lung function over time may explain FAO development.

A multiplexed microfluidic system for evaluation of dynamics of immune-tumor interactions

Recapitulation of the tumor microenvironment is critical for probing mechanisms involved in cancer, and for evaluating the tumor-killing potential of chemotherapeutic agents, targeted therapies and immunotherapies. Microfluidic devices have emerged as valuable tools for both mechanistic studies and for preclinical evaluation of therapeutic agents, due to their ability to precisely control drug concentrations and gradients of oxygen and other species in a scalable and potentially high throughput manner. Most existing in vitro microfluidic cancer models are comprised of cultured cancer cells embedded in a physiologically relevant matrix, collocated with vascular-like structures. However, the recent emergence of immune checkpoint inhibitors (ICI) as a powerful therapeutic modality against many cancers has created a need for preclinical in vitro models that accommodate interactions between tumors and immune cells, particularly for assessment of unprocessed tumor fragments harvested directly from patient biopsies. Here we report on a microfluidic model, termed EVIDENT (ex vivo immuno-oncology dynamic environment for tumor biopsies), that accommodates up to 12 separate tumor biopsy fragments interacting with flowing tumor-infiltrating lymphocytes (TILs) in a dynamic microenvironment. Flow control is achieved with a single pump in a simple and scalable configuration, and the entire system is constructed using low-sorption materials, addressing two principal concerns with existing microfluidic cancer models. The system sustains tumor fragments for multiple days, and permits real-time, high-resolution imaging of the interaction between autologous TILs and tumor fragments, enabling mapping of TIL-mediated tumor killing and testing of various ICI treatments versus tumor response. Custom image analytic algorithms based on machine learning reported here provide automated and quantitative assessment of experimental results. Initial studies indicate that the system is capable of quantifying temporal levels of TIL infiltration and tumor death, and that the EVIDENT model mimics the known in vivo tumor response to anti-PD-1 ICI treatment of flowing TILs relative to isotype control treatments for syngeneic mouse MC38 tumors.

Development of food emulsions containing an advanced performance xanthan gum by microfluidization technique

Gums are often used to increase the viscosity of the continuous phase of oil-in-water emulsions in order to reduce or inhibit some destabilization processes such as creaming. A new type of xanthan gum, advanced performance xanthan gum, which possesses improved rheological properties, has been used as a stabilizer. The addition of advanced performance xanthan gum to egg protein-based emulsions prepared at different homogenization pressures in Microfluidizer was studied. These emulsions showed different droplet size distributions and flocculation degrees. However, all the emulsions studied exhibited the same viscoelastic properties, characterized by a crossover point in the mechanical spectra. This work demonstrates the essential role of this novel gum in the rheology of emulsions. In addition, there is a direct relation between homogenization pressure and flocculation degree. This flocculation led to destabilization by coalescence in these emulsions, being the emulsion processed at the smallest homogenization pressure the most stable.

Report on the World Health Organization Global Observatory for eHealth Strategic Planning Workshop, April 2008

The World Health Organization’s Global Observatory for eHealth (GOe) conducted its first strategic workshop at Bellagio, Italy on April 9 to 11, 2008. Supported by a grant from the Rockefeller Foundation, the workshop brought together a select group of twenty-one eHealth experts from around the globe to help plan for the future of the Observatory. Participants were chosen from all six WHO regions and included a mix of researchers, practitioners, specialist physicians, academics and consultants.

Key issues addressed included: how to build a dynamic and cohesive network of National Observatories to improve worldwide eHealth data collection; analysis and reporting; developing Thematic Working Groups in specialist eHealth themes; eHealth assessment frameworks; the development of the research agenda for the second global survey; cultivating partnerships; and governance.

Long-Term Peritoneal Dialysis Experience in Portugal

Peritoneal dialysis (PD) penetration varies widely. Since the beginning of this therapy, indications have changed and outcomes have improved. In Portugal, PD still remains clearly underutilized.

The results of a 20 year PD programme were evaluated: 312 cumulative patients, 48±16 years, 27% >60 years old, 27% diabetic, 59% with prior hemodialysis (HD). The main reason for admission was vascular access failure (48.7%). Admission due to patient preference has increased significantly between first and second decades of the programme (33% vs 47% (P<0.001)); 98 patients (31.4%) were treated with automated PD but this prescription increased to 43% of the active patients.

A total of 376 Tenckhoff catheters were surgically implanted, recently by the Popovich-Moncrief technique (77 catheters): the cumulative survival was 82%, 64% and 50% at 1, 3 and 5 years, respectively. A better catheter survival was found in the last decade (85.7%, 69.6%, 54.8% versus 77.3%, 55.5%, 40.2%, at 1, 3 and 5 years, respectively (P=0.007).

The patient and technique cumulative survivals were 91, 74, 55% and 85, 67, 41%, at 1, 3, and 5 years, respectively.

The main drop-out was to hemodialysis (35.8%), followed by death (23.7%), and transplantation (21.5%). Peritonitis and access-related infections caused 35% of the transfer to HD. Cardiovascular events caused 58% of deaths. The median PD retention was 35.5 months. The rate of peritonitis has decreased to one episode /30 patient months. Hospital admission has also decreased to 4.8 days/patient year.

This is a first report on long-term PD experience in Portugal. It has been an effective modality of renal replacement therapy, reflected by the growing patient preference in our PD programme. Experience, knowledge and new technical solutions have improved the outcomes.

Genetic diversity of Bacillus sp producers of amylase isolated from the soil

The microorganisms are the best source of extracellular enzymes since they allow an economical technology with low-resource consumption compared to animals and plants. The amylases are among the most important enzymes being the genus Bacillus one of the most investigated due to its ability to produce this enzyme. The objective of this study was to isolate and analyze the genetic diversity among bacteria of the genus Bacillus sp producer of amylase originated from the soil. To this end, soil samples were collected and submitted to the condition of extreme temperature. The serial dilution procedure followed by seeding on solid medium containing starch was used for isolation of strains that produce amylase. The microorganisms isolated were subjected to standard morphological methods for presumptive identification of the genus Bacillus. The PCR assay with the universal genetic marker 16S rDNA was used for confirmation of bacterial strain. All the 10 isolates presumptively identified as bacteria amplified a fragment of 370 bp corresponding to the 16S rDNA gene. The enzymatic activity was expressed as an enzymatic index (EI), after 24 h of incubation. All isolate producers of amylase exhibited EI ≥ 2.0. The determination of the genetic profile and the clonal relationship among the isolates were performed by the method of ERIC-PCR polymorphism. The isolates of Bacillus spp were divided into 2 groups (I and II). Through this method, the discriminatory capacity of this analysis of polymorphisms was verified in differing producer strains from those not producing amylase.

Toxicologic evaluation of potassium polyaspartate (A-5D K/SD): Genotoxicity and subchronic toxicity

Potassium polyaspartate (A-5D K/SD) is proposed for use as a stabiliser in wine, with a maximum use level of 300 mg/L and typical levels in the range of 100-200 mg/L. Potassium polyaspartate (A-5D K/SD) tested negative in a bacterial reverse mutation assay performed in accordance with OECD TG 471 and in an in vitro mammalian cell micronucleus test performed in accordance with OECD TG 487. From a 90-day oral toxicity study in male and female Wistar rats performed in accordance with OECD TG 408, a no observed adverse effect level (NOAEL) was set at 1000 mg/kg bw per day, the highest dose tested. In its opinion adopted on 9 March 2016, the EFSA-ANS Panel (European Food Safety Authority - Panel on Food Additives and Nutrient Sources added to Food), considering these data, concluded that "there was no safety concern from the proposed use and use levels of potassium polyaspartate (A-5D K/SD)".

Molecular diagnosis of allergy to Anisakis simplex and Gymnorhynchus gigas fish parasites

BACKGROUND

There has been an increase in the prevalence of hypersensitivity to Anisakis simplex. There are fish parasites other than Anisakis simplex whose allergenicity has not yet been studied.

OBJECTIVE

To assess IgE hypersensitivity caused by fish parasite allergens in patients with gastro-allergic symptoms after consumption of fish, shellfish or cephalopods, compared with healthy subjects, pollen allergic individuals and children with digestive symptoms after eating marine food.

METHODS

We carried out in vivo tests (skin prick) and in vitro tests (specific IgE determination, Western blot) and component resolved diagnostics (CRD) using microarray analysis in all patients.

RESULTS

CRD better detected sensitisation to allergens from marine parasites than skin prick tests and determination of specific IgE by CAP. Sensitisation to Gymnorhynchus gigas was detected in 26% of patients measured by skin prick tests and 36% measured by IgE.

CONCLUSIONS

The prevalence of hypersensitivity to marine parasite allergens other than Anisakis simplex should be studied, and the most appropriate technique for this is CRD.

Pulse Arterial Tone and Airway Obstruction in Sleep Apnea

Objective

Determine if continuous pulse arterial tone (PAT) amplitude correlates with upper airway obstructions observed during simultaneous real-time magnetic resonance imaging (RT-MRI) in subjects with Obstructive Sleep Apnea (OSA).

Methods

A prospective series of 20 subjects diagnosed with mild to severe OSA by polysomnography, Fujita classification, Functional Outcomes of Sleep Questionnaire (FOSQ) and Epworth Sleepiness Score (ESS) underwent continuous RT-MRI during a 90-minute nap without sedation. The upper airway at the mid-saggittal plane was visualized in real time (33 fps) using a sliding window algorithm (RTHawk system). Continuous pulse arterial tone amplitude was simultaneously monitored (Watch-PAT, Itamar Inc, Israel).

Results

Changes in PAT amplitude were in phase with upper airway narrowing and obstruction from tongue, soft palate, and epiglottis movements. Airway obstructive events occurred coincident to 60% or greater decreases in PAT amplitude. The image sequence associated with each PAT amplitude decrease demonstrated the precise location of the obstruction. Pre-surgical site of airway obstruction and post-surgical cause of persistent obstruction was clearly identified.

Conclusions

RT-MRI with simultaneous and continuous PAT signal recording during natural sleep is an innovative and improved method for more precisely characterizing airway obstructions in patients with mild to severe OSA. This approach may be valuable for planning surgical treatments, potentially improving the success of these procedures.

Evaluation of the cytotoxicity (HepG2) and chemical composition of polar extracts from the ruderal species Coleostephus myconis (L.) Rchb.f

Coleostephus myconis (L.) Rchb.f. (Asteraceae) is a highly disseminated plant species with ruderal and persistent growth. Owing to its advantageous agronomic properties, C. myconis might have industrial applications. However, this species needs to be comprehensively characterized before any potential use. In a previous study, the phenolic composition and antioxidant activity of different C. myconis tissues were characterized. This investigation was extended to examine the cytotoxic potential of selected plant tissues (flowers and green parts) using a HepG2 cell line by utilizing the lysosomal neutral red uptake assay or mitochondrial (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide assay. In addition, the macronutrients content, lipophilic compounds (fatty acids, tocopherols), and amino acids were also determined. C. myconis flowers were used in the senescence stage, which was previously identified as the stage that presented maximal phenolic content and highest antioxidant activity. In contrast, stems and leaves were employed due to their high biomass proportion. Regarding cytotoxicity, mitochondrial and lysosomal damage was only significant when HepG2 cells were exposed to the highest extract concentrations (stems and leaves, 0.9 mg/ml; senescent flowers, 0.3 mg/ml). Chemically, the senescent flowers were mostly characterized by their high levels of fat, amino acids (especially threonine), oleic acid, β-, and γ-tocopherol, while stems and leaves contained high concentrations of carbohydrates, linolenic acid, and α-tocopherol. In general, these results provide information regarding the threshold concentrations of C. myconis extracts that might be used in different applications without toxicity hazards.