Bolus Feeding Research Articles

Intermittent Bolus Compared with Continuous Feeding Enhances Insulin and Amino Acid Signaling to Translation Initiation in Skeletal Muscle of Pigs Born at Term (P08-071-19)

ObjectivesOur recent study in a piglet model of the human neonate born at full term showed that intermittent bolus feeding promotes greater rates of protein synthesis in skeletal muscle than continuous feeding, leading to an increase in lean growth. This enhanced rate of muscle protein synthesis with intermittent bolus feeding is associated with an increased activation of mTORC1-dependent translation initiation. However, the mechanism underlying this response is unknown. In this study, we aimed to identify the insulin and/or amino acid signaling components involved in the enhanced stimulation of lean growth by intermittent bolus compared to continuous feeding in term-born pigs. MethodsTerm piglets (2–3 d old) were fed for 21 d an equal amount (240 ml/kg body weight [BW]/d) of sow milk replacer containing 12.8 g protein and 175 kcal/kg BW/d. Feedings were administered by gastrostomy tube either as intermittent bolus meals every 4 h (INT) or by continuous infusion (CON). After 21 d, gastrocnemius muscle was collected from CON, INT-0 (before a meal) and INT-60 (60 min after a meal) groups. Upstream and downstream insulin and amino acid signaling components of relevance to mTORC1 activation and protein translation were measured. ResultsPhosphorylation of AKT and TCS2 was greater in INT-60 than in INT-0 and CON groups (P < 0.05). There was no significant difference between CON and INT groups in the phosphorylation of ERK 1/2 and AMPK. The association of Sestrin2, a leucine sensor, with GATOR2 was similar in CON and INT-0 but was lower in INT-60 (P < 0.05). The abundances of RagA-mTOR, RagC-mTOR, and Rheb-mTOR complexes were higher in INT-60 than in CON and INT-0 (P < 0.05). The phosphorylation of S6K1 and 4EBP1 was higher in INT-60 than CON and INT-0 groups (P < 0.05). Phosphorylation of eIF2alpha and eEF2 were not affected by treatments. ConclusionsOur results demonstrate that, following a full-term birth, the enhanced rate of skeletal muscle protein synthesis and lean growth with intermittent bolus compared to continuous feeding is at least in part due to the enhanced activation of both insulin and amino acid signaling pathways leading to greater stimulation of translation initiation. Funding SourcesNIH HD085573, USDA CRIS 6250-51000-055, NIH HD072891, USDA NIFA 2013-67015-20438.

Biomass and lipid production by Rhodococcus opacus PD630 in molasses-based media with and without osmotic-stress

Rhodococcus opacus PD630 was used to produce biomass and lipids in molasses-based media with and without osmotic stress. In a 7-day aerobic batch culture at 30 °C, the biomass and lipid concentrations were maximized using an initial molasses concentration of 80 g/L and ammonium acetate (nitrogen source) concentration of 2.14 g/L. At a fixed initial molasses concentration of 80 g/L, the concentration of the nitrogen source was further fine-tuned to 2.25 g/L, to maximize the lipid content of the biomass to around 30% by dry mass. This medium was used to test the effects of stressing salts (sodium acetate, magnesium sulfate, sodium chloride) on production of lipids and biomass. A two-step bolus feeding with magnesium sulfate and sodium acetate, enhanced the final biomass concentration to around 19 g/L (a 50% increase relative to control), but the lipid content in the biomass was reduced to around 16% w/w. A 33% enhancement in lipid concentration relative to control, was achieved by feeding magnesium sulfate and sodium acetate. Sugarcane molasses could be effectively used to produce biomass and lipids instead of using the much more expensive pure carbon sources such as glucose and sucrose.

Intermittent bolus feeding promotes greater lean growth than continuous feeding in a neonatal piglet model

Orogastric tube feeding is indicated in neonates with an impaired ability to ingest food normally and can be administered with an intermittent bolus or continuous feeding schedule. The objectives were to 1) compare the long-term effect of continuous with intermittent feeding on growth using the newborn pig as a model, 2) determine whether feeding frequency alters lean tissue and fat mass gain, and 3) identify the signaling mechanisms by which protein deposition is controlled in skeletal muscle in response to feeding frequency. Neonatal pigs were fed the same amount of a balanced formula by orogastric tube either as an intermittent bolus meal every 4 h (INT) or as a continuous infusion (CON). Body composition was assessed at the start and end of the study by dual-energy X-ray absorptiometry, and hormone and substrate profiles, muscle mass, protein synthesis, and indexes of nutrient and insulin signaling were measured after 21 d. Body weight, lean mass, spine length, and skeletal muscle mass were greater in the INT group than in the CON group. Skeletal muscle fractional protein synthesis rates were greater in the INT group after a meal than in the CON group and were associated with higher circulating branched-chain amino acid and insulin concentrations. Skeletal muscle protein kinase B (PKB) and ribosomal protein S6 kinase phosphorylation and eukaryotic initiation factor (eIF) 4E-eIF4G complex formation were higher, whereas eIF2α phosphorylation was lower in the INT group than in the CON group, indicating enhanced activation of insulin and amino acid signaling to translation initiation. These results suggest that when neonates are fed the same amounts of nutrients as intermittent meals rather than continuously there is greater lean growth. This response can be ascribed, in part, to the pulsatile pattern of amino acids, insulin, or both induced by INT, which enables the responsiveness of anabolic pathways to feeding to be sustained chronically in skeletal muscle.

Effect of Different Tube Feeding Methods on the Delivery of Docosahexaenoic and Arachidonic Acid: An In Vitro Pilot Study.

Arachidonic acid (AA) and docosahexaenoic acid (DHA) are crucial for neural and visual development after premature birth. Preterm infants usually require tube feeding (TF) until the achievement of adequate oral feeding skills; the impact of TF on DHA and AA delivery has not been investigated yet. This study aimed to evaluate the effect of different TF techniques on the delivery of AA and DHA contained in human milk (HM). HM samples (65mL each) were collected and divided into three 20-mL aliquots. The remaining 5mL served as baseline. Three TF techniques were simulated (1 for each aliquot): gravity bolus feeding (BF), 3-hour continuous feeding using a horizontal feeding pump, and 3-hour continuous feeding with the feeding pump angled at 45°. For horizontal continuous feeding (HCF) and 45° angled continuous feeding (ACF), aliquots delivered between 0 and 90 minutes (T1) and 91 and 180 minutes (T2) were collected separately. AA and DHA concentration was analyzed by gas chromatography/mass spectrometry and compared among the TF methods. DHA and AA delivery at T1 and T2 was also evaluated. Fifty-one simulated feeds were performed. DHA and AA amounts after BF and ACF did not differ significantly compared with baseline, whereas HCF resulted in significantly lower DHA and AA concentration. During T2, ACF delivered almost twice the DHA and AA amounts compared with T1. The delivery of HM AA and DHA is significantly affected by TF, with potential clinical implications. When BF is not tolerated, ACF might represent a feasible alternative to reduce TF-related DHA and AA loss.

Success of Bolus Gastric Feeding After Fundoplication Among Children Who Require Preoperative Jejunal Feeding.

Management of complicated reflux in infants and children is controversial. Jejunal feedings are used when reflux complications occur with gastric feeds. We sought to determine how successful fundoplication is to allow for return of physiologic gastric feeds in patients requiring jejunal feeds preoperatively. A retrospective review of patients requiring jejunal feeds before fundoplication between 2010 and 2015 was conducted. Two hundred thirteen children underwent fundoplication during the study period. One hundred fourteen (49%) children required preoperative jejunal feeds. Median preoperative jejunal feeding trial was 15 days (interquartile range [IQR] 8-36). After fundoplication, gastric feeds were attempted in all patients. Ninety-one (80%) patients tolerated feeds postoperatively without return of preoperative symptoms. Twenty-one (18%) children developed gastric feeding intolerance and were treated with jejunal feeds at a mean of 8 months postoperatively (range 3-17). Ten (9%) children eventually tolerated intragastric bolus feeds, requiring jejunal feeds for a median duration of 2.3 months (IQR 1-5). There were no differences seen in those who were able to tolerate gastric early after the operation and those who did not. Of the patients who were unable to tolerate bolus gastric feeds during the study, a higher proportion had neurologic impairment and were on jejunal feeds for a longer period of time before fundoplication. In the majority of patients requiring continuous jejunal feeds to manage complications of reflux, fundoplication allows for transition to gastric bolus feeding.

Tolerability and safety of early enteral nutrition in children after percutaneous endoscopic gastrostomy placement: A multicentre randomised controlled trial

We assessed the tolerability and safety of implementing early enteral nutrition in children at 3h after percutaneous endoscopic gastrostomy (PEG) placement to establish an optimum feeding mode in paediatric patients that reduced the fasting period, the inadequate nutritional support interval, and the hospitalisation time. Children with clinical indications for PEG placement were recruited from six medical centres in Poland to participate in the study. The patients were centrally randomised to receive the first bolus feed, which comprised a polymeric diet (1kcal/mL), via a feeding tube at 3h (group 1) or 8h (group 2) after PEG placement. The pre-procedural preparation, the post-operative care, and the resumption of feeding were performed on all of the patients in accordance with the study's protocol. The primary endpoint was the number of patients who consumed a full feed, which contained their total fluid and caloric requirements, within 48h of the first bolus feed. The secondary endpoints were the number of complications and the duration of hospitalisation after PEG placement. Of the 97 randomised patients, 49 were assigned to group 1 and 48 were assigned to group 2. There were no differences between the groups regarding feeding tolerability (81.6% vs. 91.6%), the number of complications (25.5% vs. 37.5%), or the duration of hospitalisation after PEG placement (p>0.05). Full feed post PEG placement was achieved within 24-48h in most cases (74% vs. 82%). Most of the complications were mild. Two patients in group 2 due to dislocation of the PEG were qualified for laparotomy (at 6 days post-PEG placement in one case and at 14 days post-PEG placement in the other case). One patient in group 2 died at 7 days post-PEG placement; the death was unrelated to the investigation. Introducing feeding at 3h post-PEG placement in children appears to be well tolerated. The early initiation of post-PEG feeding was not associated with an increase in the number of complications and it had no impact on the duration of hospitalisation. CLINICAL TRIAL REGISTRY: www.clinicaltrials.gov (NCT02777541; registration date: 18/05/2016).

Energy and Fat Intake for Preterm Infants Fed Donor Milk Is Significantly Impacted by Enteral Feeding Method.

Pasteurized donor milk is the recommended supplement for preterm infants when mother's milk volumes are insufficient. Compared with mother's milk, the macronutrient content of donor milk is thought to be lower due to pasteurization and additional container changes during processing. Given that poor growth is concerning for preterm infants, it is important to understand how processing and feeding methods influence the nutrition composition of donor milk feeds. The research aim of this study was to determine the effects of pasteurization and feeding method on the macronutrient and energy composition of donor milk. Ten donor milk pools were pasteurized, prepared according to neonatal practices, and infused through nasogastric tubes to simulate 4 feeding methods: bolus, 30 minutes, 60 minutes, and continuous feeding over 4 hours. Macronutrient concentrations were assessed after pasteurization, preparation, and each feeding method using a mid-infrared human milk analyzer. There were no significant decreases in macronutrient content after pasteurization or bolus feeding. However, energy and fat losses increased with slower infusion rates. After continuous feeding for 4 hours, energy and fat concentrations decreased by a mean of 17.3 (15.8-18.8) kcal/dL and 2.08 (1.90-2.25) g/dL (P < .0001), respectively. Pasteurization did not significantly reduce donor milk macronutrient and energy content; however, feeding method significantly impacted the final delivery of energy and fat.

Methods of Enteral Nutrition Administration in Critically Ill Patients: Continuous, Cyclic, Intermittent, and Bolus Feeding.

There are several methods of enteral nutrition (EN) administration, including continuous, cyclic, intermittent, and bolus techniques, which can be used either alone or in combination. Continuous feeding involves hourly administration of EN over 24 hours assisted by a feeding pump; cyclic feeding involves administration of EN over a time period of <24 hours generally assisted by a feeding pump; intermittent feeding involves administration of EN over 20-60 minutes every 4-6 hours via pump assist or gravity assist; and bolus feeding involves administration of EN over a 4- to 10-minute period using a syringe or gravity drip. In practice, pump-assisted continuous feeding is generally acceptable for critically ill patients to prevent EN-related complications. However, a limited number of studies have been conducted to support this practice. In addition, regarding muscle protein synthesis and gastrointestinal hormone secretion, intermittent or bolus feeding may be more beneficial than continuous EN feeding for critically ill patients. For medically stable patients with feeding tubes terminating in the stomach, bolus feeding is favored with respect to practical factors, such as cost, convenience, and patient mobility. However, few studies have shown whether intermittent or bolus feeding is beneficial in a critical care setting at present. Additional randomized controlled studies comparing intermittent with bolus feeding are required.

Intermittent versus continuous feeding in critically ill adults.

Early enteral nutrition is recommended in critically ill adult patients. The optimal method of administering enteral nutrition remains unknown. Continuous enteral nutrition administration in critically ill patients remains the most common practice worldwide; however, its practice has recently been called into question in favor of intermittent enteral nutrition administration, where volume is infused multiple times per day. This review will outline the key differences between continuous and intermittent enteral nutrition, describe the metabolic responses to continuous and intermittent enteral nutrition administration and outline recent studies comparing continuous with intermittent enteral nutrition administration on outcomes in critically ill adults. In separate studies, healthy humans and critically ill patients receiving intermittent nutrition (infused over 3 h) had improved whole body protein balance from negative to positive. These studies did not have an isonitrogenous control group. A randomized controlled trial of intermittent bolus versus continuous enteral nutrition in healthy humans found that intermittent bolus feeding increased mesenteric arterial blood flow, increased insulin and peptide YY and reduced blood glucose concentration. A randomized controlled trial comparing intermittent bolus to continuous enteral nutrition in critically ill patients did not demonstrate clinically relevant differences in glycemic variability, insulin use or tube feeding volume or caloric intake between the two groups. Studies in healthy humans suggest that intermittent nutrient administration, as opposed to continuous, improves whole body protein synthesis. Unfortunately, similarly designed studies are lacking for critically ill patients. Future studies evaluating the impact of intermittent versus continuous nutrition administration on critical care outcomes should take into account factors such as protein quantity, protein quality and delivery route (enteral and/or parenteral). Until further studies are conducted in critically ill patients, a recommendation for or against intermittent nutrition delivery cannot be made.

Comparison of Continuous Versus Intermittent Bolus Feeding in Preterm Infants ≤ 32 Weeks and ≤1250 G

Comparison of Continuous Versus Intermittent Bolus Feeding in Preterm Infants ≤ 32 Weeks and ≤1250 G

Enterocin M and its Beneficial Effects in Horses-a Pilot Experiment.

Probiotic bacteria or their antimicrobial proteinaceous substances called bacteriocins (enterocins) hold promising prophylactic potential for animal breeding. This study present the results achieved after application of Enterocin M in horses. Enterocin M has never been applied to horses before. Clinically healthy horses (10) were involved in this pilot experiment. They were placed in the stables of the University of Veterinary Medicine and Pharmacy, Košice, Slovakia, with the approval of the University Ethics Committee. The animals were fed twice a day with hay and oats, or alternatively grazed with access to water ad libitum. The experiment lasted 6weeks. Sampling was performed at the start of the experiment, at day 0-1, at day 21 (3weeks of Enterocin M application), and at day 42 (3weeks of cessation). Feces were sampled directly from the rectum and blood from the vena jugularis; the samples were immediately treated and/or stored for analyses. Each horse itself represented a control animal (compared to its status at the start of the experiment, day 0-1). After initial sampling, the horses were administered 100μl of Ent M (precipitate, 12,800AU/ml) in a small feed bolus to ensure it was consumed; Ent M was applied for 3weeks (21days). Fecal samples were treated using the standard microbial dilution method; phagocytic activity was assessed with standard and flow cytometry; biochemistry and metabolic profiles were tested using commercial kits and standard methods. Administration of Ent M led to mathematical reduction of coliforms, campylobacters (abP < 0.05), and significant reduction of Clostridium spp. (abP < 0.001, bcP < 0.001); increase of PA values was noted (P < 0.05, P < 0.0001); no negative influence on hydrolytic enzyme profile or biochemical blood parameters was noted.

A critical evaluation of the anabolic response after bolus or continuous feeding in COPD and healthy older adults.

After bolus and continuous enteral feeding of the same protein, different digestion and absorption kinetics and anabolic responses are observed. Establishing which mode of feeding has the highest anabolic potential in patients with chronic obstructive pulmonary disease (COPD) may aid in the prevention of muscle wasting, but an important confounding factor is the duration of assessments after bolus feeding. We hypothesized that the anabolic response to bolus and continuous feeding in COPD patients is comparable when methodological issues are addressed. Twenty-one older adults (12 patients with stage II-IV COPD and 9 healthy controls) were studied after intake of a fast-absorbing hydrolyzed casein protein-carbohydrate mixture either as a single bolus or as small sips (crossover design). Whole body protein synthesis (PS), breakdown (PB), net PS (PS - PB) protein efficiency (netPSPE), net protein balance (phenylalanine (PHE) intake - PHE hydroxylation) protein efficiency (netBalPE), and splanchnic PHE extraction (SPEPHE) were assessed using stable isotope tracer methodology. Bolus feeding assessments were done at 90, 95, and 99% of the calculated duration of the anabolic response. At 99%, netBalPE was higher for sip feeding than bolus feeding in both groups (P<0.0001). Nevertheless, bolus feeding was associated with a lower SPEPHE (P<0.0001) and higher netPSPE (P<0.0001). At 90% compared with 99%, PS and netBalPE after bolus feeding was significantly overestimated. In conclusion, several factors complicate a comparison of the anabolic capacity of bolus and continuous feeding in acute studies, including the critical role of SPE calculation and assumptions, and the duration of postprandial assessments after bolus feeding.

Effects of Nutritional Intervention on the Survival of Patients with Cardiopulmonary Failure Undergoing Extracorporeal Membrane Oxygenation Therapy.

This study aimed to examine the effects of nutritional intervention on the prognosis of patients with cardiopulmonary failure undergoing extracorporeal membrane oxygenation (ECMO) therapy in Taiwan. An institutional review board-approved retrospective study was conducted on patients receiving ECMO therapy in the intensive care unit of the China Medical University Hospital, Taiwan, from January 2013 to December 2013. The study included 102 patients with cardiopulmonary failure receiving ECMO therapy. The data indicated that higher survival rates were closely related to lower age and APACHE II scores among the patients. In addition, compared to patients who deceased, those who survived had a higher total calorie intake. Most patients could tolerate bolus feeding and polymeric formulas. Furthermore, patients who underwent nutritional therapy with nutritional goals greater than 80% achieved a better outcome and lower mortality than other patients. Early nutritional intervention could benefit patients undergoing ECMO, and those who reached the delivery goal of 80% had significantly better outcomes than other patients. Enteral feeding can begin early and was well tolerated by patients receiving ECMO therapy. Following individual nutrition goals is critical for better outcomes, and this analysis might be useful in establishing individualized nutrition goals for oriental population when caring for critically ill patients.

Development of hyper osmotic resistant CHO host cells for enhanced antibody production

Cell culture platform processes are generally employed to shorten the duration of new product development. A fed-batch process with continuous feeding is a conventional platform process for monoclonal antibody production using Chinese hamster ovary (CHO) cells. To establish a simplified platform process, the feeding method can be changed from continuous feed to bolus feed. However, this change induces a rapid increase of osmolality by the bolus addition of nutrients. The increased osmolality suppresses cell culture growth, and the final product concentration is decreased. In this study, osmotic resistant CHO host cells were developed to attain a high product concentration. To establish hyper osmotic resistant CHO host cells, CHO-S host cells were passaged long-term in a hyper osmotic basal medium. There were marked differences in cell growth of the original and established host cells under iso- (328mOsm/kg) or hyper-osmolality (over 450mOsm/kg) conditions. Cell growth of the original CHO host cells was markedly decreased by the induction of osmotic stress, whereas cell growth of the hyper osmotic resistant CHO host cells was not affected. The maximum viable cell concentration of hyper osmotic resistant CHO host cells was 132% of CHO-S host cells after the induction of osmotic stress. Moreover, the hyper osmotic resistant characteristic of established CHO host cells was maintained even after seven passages in iso-osmolality basal medium. The use of hyper osmotic resistance CHO host cells to create a monoclonal antibody production cell line might be a new approach to increase final antibody concentrations with a fed-batch process.

A survey of bolus feeding practices in the UK home enteral feeding population

The British Artificial Nutrition Survey (2011) suggests that over 26,600 adult patients receive home enteral tube feeding (HETF) in the UK [1], and that this population is a mix of those who are bed bound/sedentary and those who are very active. Anecdotal evidence from clinicians suggests that the use of bolus feeding regimens is increasing compared to continuous/overnight feeding, allowing feeding to fit in with patient and carer lifestyles, however there is very little published evidence and understanding of this growing practice in HETF in the UK. Therefore a preliminary survey to investigate and characterise the numbers and types of adult HETF patients receiving a bolus feeding regimen was undertaken. A survey of adult (≥18 years) tube fed patients (total n=1833), who were receiving part or all of their tube feeding via a bolus feeding regimen, was undertaken across 10 HETF services in the UK between November 2015 and May 2016. A standardised questionnaire, which included patient demographics (age, gender, primary diagnosis, residential status, working status, activity level), tube type and feeding regimen details (type of feed, method, duration) and reasons for bolus feeding, was completed for each patient from their dietetic notes. Patients with bolus tube feeding regimens represented 33% (n=609) of the total HETF population surveyed. Bolus fed patients (mean age 58 years (SD 20, range 18–97), 59% male), had an average time on tube feeding of 4 years 1 month (SD 4 years 6 months, range 2 months–23 years 7 months) and an average time on a bolus feeding regimen of 3 years 6 months (SD 3 years 11 months, range 26 days–20 years 4 months). The majority of patients (73%) were fed via percutaneous endoscopic gastrostomy (PEG), resided in their own/family homes (70%) or in nursing homes (23%), and most patients were either bed/chair bound or very sedentary (69%), with the majority of patients not working (61%) or being retired (34%). Only 2% of patients were working. The most common primary diagnosis was head and neck cancer (21%), followed by stroke (16%) and cerebral palsy (12%). The head and neck cancer population were found to be much more active (78%) than the rest of the bolus fed population (30%), (seated work – moderate exercise). Of the patients surveyed, the large majority (74%) were using bolus feeding as their primary method of tube feeding either via syringe (51%) or by gravity feeding (40%). The most common reasons for choosing a bolus feeding regimen were: to top up the oral diet (20%), to mimic meal times (16%), easy (15%) and quick (12%) to use. The most commonly used feeds for bolus feeding were oral nutritional supplements (59%), with the highest proportion of these (51%) being 2.4 kcal/ml compact-style supplements. We understand this to be the largest survey of its kind specifically assessing the demographics and feeding practices of adult bolus fed patients in the UK, and showing that 1/3 of HETF patients are bolus fed. This survey largely demonstrates similarities between the demographics of those on bolus feeding regimens and the total HETF population as reported in BANS [1], although there does appear to be a dominant subgroup of head and neck cancer patients, who may be bolus feeding for different reasons. Further research is required to understand this patient group, possibly with the inclusion of specific questions regarding bolus feeding being included in future BANS surveys. Reference [1] Smith T, Micklewright A, Hirst A, Stratton RJ, Baxter J. Annual BANS Report 2011. Artificial Nutrition Support in the UK 2000–2010. BAPEN.

Comparison of Intermittent and Bolus Enteral Feeding Methods on Enteral Feeding Intolerance of Patients with Sepsis: A Triple-blind Controlled Trial in Intensive Care Units.

BACKGROUND Recent trials have shown controversial results on which enteral feeding methods has a lower risk of enteral feeding intolerance. Therefore, we aimed to compare two methods of bolus and intermittent feeding on enteral feeding intolerance of patients with sepsis. METHODS This triple-blind randomized controlled trial was conducted on 60 patients with sepsis, who were fed through tubes for at least 3 days. The patients were randomly assigned into bolus feeding, intermittent feeding, and control groups. Enteral feeding intolerance of all patients was recorded in 3 consecutive days by a researcher-made checklist including the data on gastric residual volume, vomiting, diarrhea, constipation, and abdominal distension. RESULTS There were no significant differences between the three studied groups in none of the intervention days pertaining to constipation, diarrhea, vomiting, abdominal distention, and gastric residual volume (p > 0.05). Also, no statistically significant difference was found between all variables in the three studied groups during the 3 days (p > 0.05). CONCLUSION As enteral feeding intolerance of patients with sepsis was similar in both bolus and intermittent feeding methods, it can be concluded that bolus method can still be used as a standard method to decrease the risk of enteral feeding intolerance if it is used properly

High throughput automated microbial bioreactor system used for clone selection and rapid scale-down process optimization.

High throughput automated fermentation systems have become a useful tool in early bioprocess development. In this study, we investigated a 24 x 15 mL single use microbioreactor system, ambr 15f, designed for microbial culture. We compared the fed‐batch growth and production capabilities of this system for two Escherichia coli strains, BL21 (DE3) and MC4100, and two industrially relevant molecules, hGH and scFv. In addition, different carbon sources were tested using bolus, linear or exponential feeding strategies, showing the capacity of the ambr 15f system to handle automated feeding. We used power per unit volume (P/V) as a scale criterion to compare the ambr 15f with 1 L stirred bioreactors which were previously scaled‐up to 20 L with a different biological system, thus showing a potential 1,300 fold scale comparability in terms of both growth and product yield. By exposing the cells grown in the ambr 15f system to a level of shear expected in an industrial centrifuge, we determined that the cells are as robust as those from a bench scale bioreactor. These results provide evidence that the ambr 15f system is an efficient high throughput microbial system that can be used for strain and molecule selection as well as rapid scale‐up. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 34:58–68, 2018

How to set up and administer an enteral feed via a nasogastric tube.

Rationale and key points Nasogastric tube feeding is a method of enteral feeding commonly administered by nurses. Feed can be administered either using a volumetric enteral feeding pump (pump feeding) or via an enteral syringe (bolus feeding). This article explains how nurses can safely undertake these two methods of nasogastric tube feed administration at the patient's bedside. » Nasogastric tube feeding can be used to provide some or all of the patient's nutrition, fluid or medication. » Nurses should be equipped with the relevant knowledge to flush a nasogastric tube before the administration of feed or medication; set up and administer an enteral feed via a volumetric enteral feeding pump; and set up and administer a feed using a bolus method. » The position of the distal tip of the nasogastric tube must be confirmed as sitting in the patient's stomach before the tube is used to administer enteral feed, fluid or medication. Reflective activity 'How to' articles can help you update your practice and ensure it remains evidence-based. Apply this article to your practice. Reflect on and write a short account of: 1. How you think this article will change your practice when setting up and administering an enteral feed via a nasogastric tube. 2. How you could use this resource to educate your colleagues about nasogastric tube feeding via an enteral feeding pump or bolus feeding.

Extraction of indirectly captured information for use in a comparison of offline pH measurement technologies

Understanding the causes of discrepancies in pH readings of a sample can allow more robust pH control strategies to be implemented. It was found that 59.4% of differences between two offline pH measurement technologies for an historical dataset lay outside an expected instrument error range of ±0.02pH. A new variable, OsmoRes, was created using multiple linear regression (MLR) to extract information indirectly captured in the recorded measurements for osmolality. Principal component analysis and time series analysis were used to validate the expansion of the historical dataset with the new variable OsmoRes. MLR was used to identify variables strongly correlated (p<0.05) with differences in pH readings by the two offline pH measurement technologies. These included concentrations of specific chemicals (e.g. glucose) and OsmoRes, indicating culture medium and bolus feed additions as possible causes of discrepancies between the offline pH measurement technologies. Temperature was also identified as statistically significant. It is suggested that this was a result of differences in pH-temperature compensations employed by the pH measurement technologies. In summary, a method for extracting indirectly captured information has been demonstrated, and it has been shown that competing pH measurement technologies were not necessarily interchangeable at the desired level of control (±0.02pH).

Effects of high concentrations of crude glycerin in diets for feedlot lambs: feeding behaviour, growth performance, carcass and non-carcass traits

The effects of high concentrations of crude glycerin were investigated in diets for feedlot lambs. Forty crossbred (Santa Ines × Dorper) uncastrated male lambs (21.7 ± 2.7 kg bodyweight) were assigned to a complete randomised block and subjected to four experimental diets containing 0, 100, 200, or 300 g crude glycerin/kg DM. Animals were weighed at 14-day intervals and were harvested when they reached ~35 kg bodyweight. The feed intake, feeding behaviour, growth performance, carcass and meat traits, and edible non-carcass components were evaluated. The inclusion of more than 100 g/kg crude glycerin in the diets increased days on feed and decreased DM intake and average daily gain. Crude glycerin increased number of chews and the time spent chewing per feed bolus. There were no effects of crude glycerin on pH and colour of Longissimus muscle at 45 min or 24 h after slaughter, as well as on other carcass and edible non-carcass characteristics. The addition of crude glycerin reduced perirenal fat without detrimental effect on others fat deposition sites. In conclusion, the addition of up to 100 g/kg DM in diets for crossbred finishing lambs seems to be the most interesting strategy, as it promotes greatest animal performance. However, the inclusion of up to 300 g/kg DM of the by-product could be possible depending on glycerin market price and the structure of feedlot operation, with favourable economic results despite high inclusions reflect in greater number of days on feed.