Encapsulation of Bifidobacterium longum in alginate-dairy matrices and survival in simulated gastrointestinal conditions, refrigeration, cow milk and goat milk

The aim of this study was to microencapsulate Bifidobacterium longum subsp. infantis CCUG 52486 using the extrusion method in a variety of matrices, namely sodium alginate (SA), sodium alginate-cow milk (SACM), sodium alginate-goat milk (SAGM) and sodium alginate-casein hydrolysate (SACH), and to evaluate the survival of free and encapsulated bacterial cells under different conditions. The encapsulation yield, size and surface morphology of the microcapsules were evaluated. The survival of microencapsulated bacterial cells and free bacterial cells were evaluated under simulated gastrointestinal conditions as well as in refrigeration, cow milk and goat milk during storage at 4 oC for 28 days. The average size of SACM capsules and SAGM capsules was 2.8±0.3 mm and 3.1±0.2 mm respectively. Goat milk and cow milk based matrices resulted in dense microcapsules which led to better performances in simulated gastrointestinal conditions than SA and SACH microcapsules. The bacterial cells encapsulated in SAGM showed the highest survival rate in cow milk (7.61 log cfu g-1) and goat milk (8.10 log cfu g-1) after the storage of 28 d. The cells encapsulated in SA and SACH and the free cells performed poorly under the simulated gastrointestinal conditions and in all different storage conditions. This study showed that SACM and SAGM are suitable to encapsulate B. longum subsp. infantis CCUG 52486 using the extrusion technique and more specifically, SAGM has a potential to be used as a new encapsulation material for encapsulating probiotic bacteria, resulting milk and goat milk-based products with higher probiotic cell concentrations during refrigerated storage

Poly-(γ-glutamic acid) Production and Optimization from Agro-Industrial Bioresources as Renewable Substrates by Bacillus sp. FBL-2 through Response Surface Methodology

We optimized culture conditions using Bacillus sp. FBL-2 as a poly-(γ-glutamic acid) (PGA) producing strain isolated from cheonggukjang. All experiments were performed under aerobic conditions using a laboratory scale 2.5 L fermentor. We investigated the effects of fermentation parameters (temperature, pH, agitation, and aeration) and medium components (glutamic acid, citric acid, and yeast extract) on poly-(γ-glutamic acid) production, viscosity, and dry cell mass. A non-optimized fermentation method (1.5 vvm, 350 rpm, and 37 °C) yielded PGA, viscosity, and dry cell mass at levels of 100.7 g/L, 483.2 cP, and 3.4 g/L, respectively. L-glutamic acid, citric acid, and yeast extract supplementation enhanced poly-(γ-glutamic acid) production to 175.9 g/L. Additionally, the production of poly-(γ-glutamic acid) from rice bran and wheat bran was assessed using response surface methodology (central composite rotatable design). Agricultural by-products (rice bran and wheat bran) and H2SO4 were selected as factors, and experiments were performed by combining various component concentrations to determine optimal component concentrations. Our experimentally-derived optimal parameters included 38.6 g/L of rice bran, 0.42% of H2SO4, 28.0 g/L of wheat bran, and 0.32% of H2SO4. Under optimum conditions, rice bran medium facilitated poly-(γ-glutamic acid) production of up to 22.64 g/L, and the use of wheat bran medium yielded up to 14.6 g/L. Based on a validity test using the optimized culture conditions, poly-(γ-glutamic acid) was produced at 47.6 g/L and 36.4 g/L from these respective mediums, and both results were higher than statistically predicted. This study suggests that rice bran can be used as a potential alternative substrate for poly-(γ-glutamic acid) production

Percutaneous ablation techniques for renal cell carcinoma: current status and future trends

Percutaneous ablation is an increasingly applied technique for the treatment of localized renal tumors, especially for elderly or co-morbid patients, where co-morbidities increase the risk of traditional nephrectomy. Ablative techniques are technically suited for the treatment of tumors generally not exceeding 4 cm, which has been set as general consensus cutoff and is described as the upper threshold of T1a kidney tumors. This threshold cutoff is being challenged, but with still limited evidence. Percutaneous ablation techniques for the treatment of renal cell carcinoma (RCC) include radiofrequency ablation, cryoablation, laser or microwave ablation; the main advantage of all these techniques over surgery is less invasiveness, lower complication rates and better patient tolerability. Currently, international guidelines recommend percutaneous ablation either as intervention for frail patients or as a first line tool, provided that the tumor can be radically ablated. The purpose of this article is to describe the basic concepts of percutaneous ablation in the treatment of RCC. Controversies concerning techniques and products and the need for patient-centered tailored approaches during selection among the different techniques available will be discussed

Enteric coated spheres produced by extrusion/spheronization provide effective gastric protection and efficient release of live therapeutic bacteria

We present a novel but simple enteric coated sphere formulation containing probiotic bacteria (Lactobacillus casei). Oral delivery of live bacterial cells (LBC) requires live cells to survive firstly manufacturing processes and secondly GI microbicidal defenses including gastric acid. We incorporated live L. casei directly in the granulation liquid, followed by granulation, extrusion, spheronization, drying and spray coating to produce dried live probiotic spheres. A blend of MCC, calcium-crosslinked alginate, and lactose was developed that gave improved live cell survival during manufacturing, and gave excellent protection from gastric acid plus rapid release in intestinal conditions. No significant loss of viability was observed in all steps except drying, which resulted in approximately 1 log loss of viable cells. Eudragit coating was used to protect dried live cells from acid, and microcrystalline cellulose (MCC) was combined with sodium alginate to achieve efficient sphere disintegration leading to rapid and complete bacterial cell release in intestinal conditions. Viability and release of L. casei was evaluated in vitro in simulated GI conditions. Uncoated spheres gave partial acid protection, but enteric coated spheres effectively protected dried probiotic LBC from acid for 2 h, and subsequently released all viable cells within 1h of transfer into simulated intestinal fluid

Weighted Shortest Common Supersequence problem revisited

A weighted string, also known as a position weight matrix, is a sequence of probability distributions over some alphabet. We revisit the Weighted Shortest Common Supersequence (WSCS) problem, introduced by Amir et al. [SPIRE 2011], that is, the SCS problem on weighted strings. In the WSCS problem, we are given two weighted strings (Formula presented) and (Formula presented) and a threshold (Formula presented) on probability, and we are asked to compute the shortest (standard) string S such that both (Formula presented) and (Formula presented) match subsequences of S (not necessarily the same

Combining creative writing and narrative analysis to deliver new insights into the impact of pulmonary hypertension

Introduction Pulmonary hypertension is life-limiting. Delays in diagnosis are common, and even after treatment has been initiated, pulmonary hypertension has marked effects on many aspects of social and physical function. We believed that a new approach to examining disease impact could be achieved through a combination of narrative research and creative writing. Methods Detailed unstructured narrative interviews with people with pulmonary hypertension were analysed thematically. Individual moments were also summarised and studied using creative writing, in which the interviewer created microstories from narrative and interview data. Stories were shared with their subjects, and with other patients, clinicians, researchers and the wider public. The study was carried out in hospital and in patients’ homes. Results Narrative analysis generated a rich data set which highlighted profound effects of pulmonary hypertension on identity, and demonstrated how the disease results in very marked personal change with ongoing and unpredictable requirement for adaptation. The novel methodology of microstory development proved to be an effective tool to summarise, communicate, and explore the consequences of pulmonary hypertension and the clinical challenges of caring for patients with this illness. Conclusions A holistic approach to treatment of chronic respiratory diseases such as pulmonary hypertension requires and benefits from explicit exploration of the full impacts of the illness. Narrative analysis and the novel approach of targeted microstory development can form a valuable component of the repertoire of approaches to effectively comprehend chronic disease and can also facilitate patient-focused discussion and interventions

Improving survival of probiotic bacteria using bacterial poly-γ-glutamic acid

A major hurdle in producing a useful probiotic food product is bacterial survival during storage and ingestion. The aim of this study was to test the effect of γ-PGA immobilisation on the survival of probiotic bacteria when stored in acidic fruit juice. Fruit juices provide an alternative means of probiotic delivery, especially to lactose intolerant individuals. In addition, the survival of γ-PGA-immobilised cells in simulated gastric juice was also assessed. Bifidobacteria strains (B. longum, B. breve), immobilised on 2.5 % γ-PGA, survived significantly better (P < 0.05) in orange and pomegranate juice for 39 and 11 days respectively, compared to free cells. However, cells survived significantly better (P < 0.05) when stored in orange juice compared to pomegranate juice. Moreover, both strains, when protected with 2.5 % γ-PGA, survived in simulated gastric juice (pH 2.0) with a marginal reduction (<0.47 log CFU/ml) or no significant reduction in viable cells after four hours, whereas free cells died within two hours. In conclusion, this research indicates that γ-PGA can be used to protect Bifidobacteria cells in fruit juice, and could also help improve the survival of cells as they pass through the harsh conditions of the gastrointestinal tract (GIT). Following our previous report on the use of γ-PGA as a cryoprotectant for probiotic bacteria, this research further suggests that γ-PGA could be used to improve probiotic survival during the various stages of preparation, storage and ingestion of probiotic cells

Clinical predictors of all‐cause mortality in patients presenting to specialist heart failure clinic with raised NT‐proBNP and no heart failure

Aims Clinical outcomes for patients suspected of having heart failure (HF) who do not meet the diagnostic criteria of any type of HF by echocardiography remain unknown. The aim of this study was to investigate the clinical predictors of all‐cause mortality in patients with suspected HF, a raised N‐terminal pro‐b‐type natriuretic peptide (NTproBNP) and who do not meet the diagnostic criteria of any type of HF by echocardiography. Methods and results Relevant data were taken from the S heffield HEA rt F ailure (SHEAF) registry (222349P4). The inclusion criteria were presence of symptoms raising suspicion of HF, NTproBNP > 400 pg/mL, and preserved left ventricular function. Exclusion criteria were any type of HF by echocardiography. The outcome was defined as all‐cause mortality. Cox proportional‐hazards regression model was used to investigate the association between the survival time of patients and clinical variables; 1031 patients were identified with NTproBNP > 400 pg/mL but who did not have echocardiographic evidence of HF. All‐cause mortality was 21.5% (222 deaths) over the mean follow‐up (FU) period of 6 ± 2 years. NTproBNP was similar in patients who were alive or dead (P = 0.96). However, age (HR 1, P 627 pg/mL, NYHA class predicted death (II, 19.6%; III, 27.4%; IV, 66.7%; P < 0.01). Conclusions Patients with no HF on echocardiography but raised NTproBNP suffer excess mortality particularly in the presence of certain clinical variables. Age, male gender, worsening CKD stage, presence of COPD, and dementia are independently associated with all‐cause mortality in these patients. An NTproBNP > 627 pg/mL coupled with NYHA class could identify patients at greatest risk of death

Clinic variation in glycaemic control for children with Type 1 diabetes in England and Wales:a population-based, multilevel analysis

AIM: To understand the scope for improving children's glycaemic outcomes by reducing variation between clinics and examine the role of insulin regimen and clinic characteristics. METHODS: Cross-sectional analysis of 2012-2013 National Paediatric Diabetes Audit data from 21 773 children aged < 19 years with Type 1 diabetes cared for at 176 clinics organized into 11 regional diabetes networks in England and Wales. Variation in HbA1c was explored by multilevel models with a random effect for clinic. The impact of clinic context was quantified by computing the per cent of total variation in HbA1c which occurs between clinics (intraclass correlation coefficient; ICC). RESULTS: Overall, 69 of the 176 diabetes clinics (39%) had a glycaemic performance that differed significantly from the national average after adjusting for patient case-mix with respect to age, gender, diabetes duration, deprivation and ethnicity. However, differences between clinics accounted for 4.7% of the total variation in HbA1c . Inclusion of within-clinic HbA1c standard deviation led to a substantial reduction in ICC to 2.4%. Insulin regimen, clinic volume and diabetes networks had a small or moderate impact on ICC. CONCLUSIONS: Differences between diabetes clinics accounted for only a small portion of the total variation in glycaemic control because most of the variation was within clinics. This implies that national glycaemic improvements might best be achieved not only by targeting poor centres but also by shifting the whole distribution of clinics to higher levels of quality

Probiotic microcarrier: a continuous folate producer

The recommended daily intake of folate (B-complex vitamin) for an adult varies between 200-400 µg, being the intake of folate inefficient due its extremely unstable chemical forms. The aim of this work is the creation of model to folate in situ production using probiotics. However, three main issues need to be overcome: (a) probiotic bacteria should be protected towards the gastric medium (encapsulation); (b) microcarriers size should be smaller than 100 µm, to avoid modifying food texture; and (c) microcarriers should adhere to gut epithelium in order to increase bacteria residence time. Lactococcus lactis cremoris was grown in milk (30ºC). Alginate-based microcarriers were produced and three layers were built using the layer-by-layer technique in that worder: poly-L-lysine; sodium alginate; chitosan. Confocal microscopy was used to confirm the consequent adhesion of the layers (poly-L-lysine/FITC; chitosan/rhodamine). After production the microcarriers where put into a 10 mL solution of KCl-HCl (pH 2 - 1 hour), at 100 rpm and then into a PBS solution (pH 7.2 - 3 hours) in order to mimic the passage through the gastrointestinal tract. The utilization of free bacteria (LLC) in milk showed an increase of folate content in 4.73 µg/L after 6 h. The average size of the microcarriers from 21.01 ± 0.49 µm to 39.84 ± 0.79 µm when the pH increased from 2 to 7.2. The size averages obtained were smaller than 100 µm and showed a swelling capacity (particles duplicate their size upon passing from pH 2 to pH 7.2), being confirmed by confocal microscopy images the correct adhesion of the different layers after this experiment and the stability of the microcarriers. Microcarriers produced through LbL showed great potential for encapsulation of probiotics, allowing their protection against harsh gastrointestinal conditions, predicting their use as a microcarrier for in situ folate production