Branched-chain amino acid supplementation does not improve measures of sarcopenia in cirrhosis: results of a randomised controlled trial

BACKGROUND

Sarcopenia is associated with adverse outcomes in cirrhosis. Branched-chain amino acids (BCAA) target several pathways that lead to muscle loss in this population.

AIMS

We aimed to evaluate the impact of BCAA supplementation on sarcopenia measures in patients with cirrhosis.

METHODS

We conducted a 12-month double-blinded, randomised, controlled trial of BCAA supplementation (30 g daily) compared to an equicaloric, equi-nitrogenous whey protein in volunteers with cirrhosis and reduced muscle strength. The primary endpoint was an increase in grip strength and upper limb lean mass measured on DEXA. Mean-adjusted differences (MAD, 95% CI) between groups at 6 and 12 months are reported as treatment effect using a linear mixed model for repeated measures.

RESULTS

A total of 150 volunteers entered the trial (74 BCAA, 76 control), with a median age of 58 years [IQR 48; 63] and MELD of 14 [12; 17]. At 12 months, 57% in the BCAA arm and 61% in the control arm met the primary endpoint (p = 0.80). No significant between-group difference was found in grip strength (MAD -0.15 kg [-0.37; 0.06], p = 0.29) or upper limb lean mass (1.7 kg [-0.2; 3.6], p = 0.22) at 12 months. No significant differences in other body composition parameters, physical performance, frailty, rates of hospitalisation or mortality were found between the BCAA and the control group. Fatigue improved across the entire cohort, without significant between-group differences. 15% of volunteers reported side effects, with distaste higher in the BCAA arm (p = 0.045).

CONCLUSION

BCAA supplementation did not improve measures of muscle strength, mass or performance or physical frailty compared to a whey protein supplement in a randomised controlled setting. ACTRN12618000802202.

Reversing malnutrition and low muscle strength with targeted enteral feeding in patients awaiting liver transplant: A randomized controlled trial

BACKGROUND AND AIMS

Most patients with decompensated cirrhosis fail to meet their nutrition targets. The impact of nasogastric feeding (NGF) on malnutrition in cirrhosis remains unknown. This study aims to assess the impact of pretransplant NGF on pre-liver transplant and post-liver transplant outcomes.

APPROACH AND RESULTS

This single-center, prospective randomized controlled trial of 55 patients with severe malnutrition and low handgrip strength (HGS) compared a standard high-energy high-protein diet to diet plus supplemental nocturnal NGF while awaiting transplant. The primary outcome was a change in HGS. The median age was 58.5 years (IQR: 51.1-64), median MELD was 24 (20-28.5), and 32 (58%) patients were male. The median duration of NGF was 63.0 days (34.5-127), following which time the median between-group difference in HGS was 3.6 kg (95% CI: 1.7-5.2, p <0.001), an increase of 20% from baseline. Mid-upper-arm circumference, triceps skinfold, and immune function all increased significantly with NGF. Muscle and nutritional parameters continued to improve with increasing duration of feeding. NGF significantly increased daily energy intake between groups by 1285 kcal (95% CI: 860-1677) and protein intake by 51 g (95% CI: 32-71) (both p <0.001). All NGF patients met >100% of their measured nutritional requirements. Posttransplant clinical outcomes were similar between groups.

CONCLUSIONS

Targeted enteral feeding before liver transplant improves HGS, anthropometry, and immune function in severely malnourished patients with cirrhosis. These findings provide a strong rationale for early consideration of NGF to reverse malnutrition and improve muscle strength. Appropriately powered studies should explore whether NGF can also impact clinically relevant outcomes including pretransplant and posttransplant mortality.

Continuous home terlipressin infusion increases handgrip strength and reduces ascites-A prospective randomized crossover study

BACKGROUND AND AIMS

Observational studies suggest a beneficial effect of continuous terlipressin infusion (CTI) on ascites and sarcopenia in decompensated cirrhosis with portal hypertension.

APPROACH AND RESULTS

This single-center, prospective, cross-over study randomized 30 patients with cirrhosis, ascites, and sarcopenia to commence on 12 weeks of home CTI or 12 weeks of observation prior to cross-over. The co-primary outcomes were change in handgrip strength and paracentesis volume. Secondary outcomes included quality of life, sarcopenia measures, renal function, safety, and hospitalization. The median age of participants was 62 years (IQR: 57-64), the median Model for End-Stage Liver Disease-Sodium was 16 (12.3-20.8), and 22 (73%) were male. Handgrip strength increased by a mean adjusted difference (MAD) of 3.09 kg (95% CI: 1.11-5.08 kg) between CTI and observation ( p =0.006); an 11.8% increase from baseline. The total volume of ascites drained decreased by a MAD of 11.39L (2.99-19.85, p =0.01), with 1.75 fewer episodes of paracentesis (0.925-2.59, p <0.001) on CTI. Serum creatinine decreased, urinary sodium excretion increased, and quality of life was significantly higher on CTI (all p <0.001), with an increase in Chronic Liver Disease Questionnaire score of 0.41 points (0.23-0.59). There were 7 minor line-related complications but no cardiac events or pulmonary edema.

CONCLUSIONS

This novel study demonstrates a significant increase in handgrip strength, reduction in paracentesis volume, and improved quality of life in patients with decompensated cirrhosis treated with continuous terlipressin infusion. These findings provide a strong rationale for the use of ambulatory CTI in appropriately selected patients with cirrhosis.

Redefining Nutritional Requirements in End-Stage Liver Disease: Towards a Personalized Approach

Malnutrition is ubiquitous in cirrhotic patients presenting for liver transplant (LT). Providing an appropriate energy prescription is fundamental to effective nutrition therapy. We aimed to compare measured energy expenditure (mEE) with predicted energy expenditure (pEE) in patients awaiting LT and determine clinical factors associated with mEE. In this prospective observational study, energy expenditure was measured by indirect calorimetry in 110 adult patients referred for LT and predicted by commonly utilized equations (Harris-Benedict, Schofield, and EASL guidelines). Nutritional status, anthropometry, muscle function, biochemical and clinical data were also collected. The median model for end-stage liver disease (MELD) was 19 (IQR 13, 25), and the majority were Child-Pugh B (51%) or C (37%). Malnutrition was evident in 85%. Median mEE by calorimetry was 1756 (1531, 2104) kcal/d and significantly higher than pEE as per Harris-Benedict 1480 (1322, 1722) kcal/d and Schofield 1474 (1349, 1723) kcal/d (both p < 0.001), but lower than EASL guidelines (35 kcal/kg) when an activity factor was applied to mEE; 2283 (1990, 2735) kcal/d versus 2590 (2178, 3010) kcal/d (p < 0.001). Hypermetabolism (mEE:pEE > 1.2) was evident in 48% of the cohort. Multivariate analysis found MELD, Child-Pugh class, diuretic use, and severe malnutrition to be independent predictors of hypermetabolism. A new liver-specific predictive model has been developed, showing superior agreement with mEE than common predictive equations. In conclusion, there is a poor correlation between mEE and pEE in patients awaiting LTs, and hypermetabolism is common. Relying on historical predictive equations in this patient population may result in significant under or over-feeding. A tailored energy prescription based on indirect calorimetry or a liver-specific predictive model is recommended for LT candidates.

Transjugular intrahepatic portosystemic shunt insertion improves muscle mass but not muscle function or frailty measures

INTRODUCTION

Sarcopenia in cirrhosis is associated with poor outcomes. While transjugular intrahepatic portosystemic shunt (TIPS) insertion improves radiological measures of muscle mass, its impact on muscle function, performance and frailty has not been evaluated.

METHODS

Patients with cirrhosis referred for TIPS were prospectively recruited and followed for 6 months. L3 CT scans were used to calculate skeletal muscle and adipose tissue parameters. Handgrip strength, Liver Frailty Index and short physical performance battery were serially monitored. Dietary intake, insulin resistance, insulin-like growth factor (IGF)-1, and immune function using QuantiFERON Monitor (QFM) were measured.

RESULTS

Twelve patients completed the study with a mean age of 58 ± 9 years and model for end-stage liver disease score of 16 ± 5. At 6 months post-TIPS, skeletal muscle area increased from 139.33 cm 2  ± 22.72 to 154.64 ± 27.42 ( P  = 0.012). Significant increases were observed in the subcutaneous fat area ( P  = 0.0076) and intermuscular adipose tissue ( P  = 0.041), but not muscle attenuation or visceral fat. Despite marked changes in muscle mass, no improvements were observed in handgrip strength, frailty, or physical performance. At 6 months post-TIPS, IGF-1 ( P  = 0.0076) and QFM ( P  = 0.006) increased compared to baseline. Nutritional intake, hepatic encephalopathy measures, insulin resistance and liver biochemistry were not significantly impacted.

CONCLUSION

Muscle mass increased following TIPS insertion as did IGF-1, a known driver of muscle anabolism. The lack of improvement in muscle function was unexpected and may relate to impairment in muscle quality and the effects of hyperammonaemia on muscle contractile function. Improvements in QFM, a marker of immune function, may suggest a reduction in infection susceptibility in this at-risk population and requires further evaluation.

Novel Use of the Crohn's Disease Exclusion Diet Plus Partial Enteral Nutrition for the Treatment of Crohn's Disease During Pregnancy

The Crohn's Disease Exclusion Diet (CDED) with partial enteral nutrition (PEN) is an emerging treatment option for Crohn's disease (CD). A 35-year-old pregnant woman presented with newly diagnosed ileal CD. At 14/40 gestation, CDED + PEN was prescribed without drug therapy. Outcomes included Harvey-Bradshaw Index, weight, and bowel wall thickness/Limberg score measured on intestinal ultrasound (IUS). In this patient, CDED + PEN achieved clinical and biochemical remission, improvements on IUS, gestational weight gain, and healthy birth weight without drug therapy. Sustained remission was achieved postpartum. Our case highlights the potential effectiveness of CDED + PEN to induce remission for active CD during pregnancy.

Characteristics of adult patients with chronic intestinal failure due to short bowel syndrome: An international multicenter survey

BACKGROUND AND AIMS

The case-mix of patients with intestinal failure due to short bowel syndrome (SBS-IF) can differ among centres and may also be affected by the timeframe of data collection. Therefore, the ESPEN international multicenter cross-sectional survey was analyzed to compare the characteristics of SBS-IF cohorts collected within the same timeframe in different countries.

METHODS

The study included 1880 adult SBS-IF patients collected in 2015 by 65 centres from 22 countries. The demographic, nutritional, SBS type (end jejunostomy, SBS-J; jejuno-colic anastomosis, SBS-JC; jejunoileal anastomosis with an intact colon and ileocecal valve, SBS-JIC), underlying disease and intravenous supplementation (IVS) characteristics were analyzed. IVS was classified as fluid and electrolyte alone (FE) or parenteral nutrition admixture (PN). The mean daily IVS volume, calculated on a weekly basis, was categorized as <1, 1-2, 2-3 and >3 L/day.

RESULTS

In the entire group: 60.7% were females and SBS-J comprised 60% of cases, while mesenteric ischaemia (MI) and Crohn' disease (CD) were the main underlying diseases. IVS dependency was longer than 3 years in around 50% of cases; IVS was infused ≥5 days/week in 75% and FE in 10% of cases. Within the SBS-IF cohort: CD was twice and thrice more frequent in SBS-J than SBS-JC and SBS-JIC, respectively, while MI was more frequent in SBS-JC and SBS-JIC. Within countries: SBS-J represented 75% or more of patients in UK and Denmark and 50-60% in the other countries, except Poland where SBS-JC prevailed. CD was the main underlying disease in UK, USA, Denmark and The Netherlands, while MI prevailed in France, Italy and Poland.

CONCLUSIONS

SBS-IF type is primarily determined by the underlying disease, with significant variation between countries. These novel data will be useful for planning and managing both clinical activity and research studies on SBS.

Exercise physiology in cirrhosis and the potential benefits of exercise interventions: A review

Reduction in muscle mass is a highly prevalent phenomenon in cirrhosis and is now well-documented to be associated with significant morbidity and mortality. Research into muscle loss in cirrhosis remains limited by an ongoing poor understanding of its relationship with muscle function, physical activity, and aerobic capacity. Alterations in exercise physiology have been documented in studies of individuals with cirrhosis that provide important information on physical function that is not captured by simple quantification of muscle mass. Despite expert consensus recommending regular exercise in end-stage liver disease to maintain muscle mass and function, there is little evidence guiding clinicians as to which form of exercise or delivery mechanism is most effective. It also remains unproven whether any specific intervention can alter clinically relevant outcomes. This review article summarizes the available literature regarding the changes in exercise physiology observed in cirrhosis, the associated impact on physical capacity, and the results of existing trials that examine the potential benefits of exercise delivery in patients with cirrhosis, particularly pertaining to their impact on exercise physiology.

Mycosands: Fungal diversity and abundance in beach sand and recreational waters - Relevance to human health

The goal of most studies published on sand contaminants is to gather and discuss knowledge to avoid faecal contamination of water by run-offs and tide-retractions. Other life forms in the sand, however, are seldom studied but always pointed out as relevant. The Mycosands initiative was created to generate data on fungi in beach sands and waters, of both coastal and freshwater inland bathing sites. A team of medical mycologists and water quality specialists explored the sand culturable mycobiota of 91 bathing sites, and water of 67 of these, spanning from the Atlantic to the Eastern Mediterranean coasts, including the Italian lakes and the Adriatic, Baltic, and Black Seas. Sydney (Australia) was also included in the study. Thirteen countries took part in the initiative. The present study considered several fungal parameters (all fungi, several species of the genus Aspergillus and Candida and the genera themselves, plus other yeasts, allergenic fungi, dematiaceous fungi and dermatophytes). The study considered four variables that the team expected would influence the results of the analytical parameters, such as coast or inland location, urban and non-urban sites, period of the year, geographical proximity and type of sediment. The genera most frequently found were Aspergillus spp., Candida spp., Fusarium spp. and Cryptococcus spp. both in sand and in water. A site-blind median was found to be 89 Colony-Forming Units (CFU) of fungi per gram of sand in coastal and inland freshwaters, with variability between 0 and 6400 CFU/g. For freshwater sites, that number was 201.7 CFU/g (0, 6400 CFU/g (p = 0.01)) and for coastal sites was 76.7 CFU/g (0, 3497.5 CFU/g). For coastal waters and all waters, the median was 0 CFU/ml (0, 1592 CFU/ml) and for freshwaters 6.7 (0, 310.0) CFU/ml (p < 0.001). The results advocate that beaches should be monitored for fungi for safer use and better management.

Hearts above water: Palliative care during a pandemic

Social workers and nurses, as members of interprofessional palliative medicine teams, faced unfamiliar challenges and opportunities as they endeavored to provide humanistic care to patients and families during the coronavirus (COVID-19) pandemic. Typical methods for engaging patients and families in medical decision-making became thwarted by visitation restrictions and patients' dramatic health declines. This paper presents an innovative social work and nursing intervention aimed at enhancing humanistic patient/family care and advanced directive dialogs. Through incorporating a narrative synthesis of the teams' reflective journals from COVID-19, the paper chronicles the intervention implementation, patient/family responses, and team members' personal and professional meaning-making processes.

Nutraceuticals for the treatment of sarcopenia in chronic liver disease

BACKGROUND AND AIMS

Sarcopenia, defined as loss of muscle mass, strength and function, is associated with adverse clinical outcomes in patients with cirrhosis. Despite improved understanding of the multifaceted pathogenesis, there are few established therapies to treat or prevent muscle loss in this population. This narrative review examines the available literature investigating the role of nutraceuticals for the prevention or treatment of muscle wasting in chronic liver disease.

METHODS

A comprehensive search or Medline and PubMED databases was conducted. Reference lists were screened to identify additional articles.

RESULTS

A number of nutritional supplements and vitamins target the specific metabolic derangements that contribute to sarcopenia in cirrhosis including altered amino acid metabolism, hyperammonaemia and inflammation. Branched chain amino acid (BCAA) supplementation has proposed anabolic effects through dual pathways of enhanced ammonia clearance and stimulation of muscle protein synthesis. l-carnitine also has multimodal effects on muscle and shows promise as a therapy for muscle loss through anti-inflammatory, antioxidant and ammonia lowering properties. Other nutraceuticals including l-ornithine l-aspartate, omega-3 polyunsaturated fatty acids and zinc and vitamin D supplementation, may similarly have positive effects on muscle homeostasis, however further evidence to support their use in cirrhotic populations is required.

CONCLUSION

Nutraceuticals offer a promising and likely safe adjunct to standard care for sarcopenia in cirrhosis. While there is most evidence to support the use of BCAA and l-carnitine supplementation, further well-designed clinical trials are needed to elucidate their efficacy as a therapy for muscle loss in this population.

Malnutrition in cirrhosis: More food for thought

Malnutrition is highly prevalent in liver cirrhosis and its presence carries important prognostic implications. The clinical conditions and pathophysiological mechanisms that cause malnutrition in cirrhosis are multiple and interrelated. Anorexia and liver decompensation symptoms lead to poor dietary intake; metabolic changes characterised by elevated energy expenditure, reduced glycogen storage, an accelerated starvation response and protein catabolism result in muscle and fat wasting; and, malabsorption renders the cirrhotic patient unable to fully absorb or utilise food that has been consumed. Malnutrition is therefore a considerable challenge to manage effectively, particularly as liver disease progresses. A high energy, high protein diet is recognised as standard of care, yet patients struggle to follow this recommendation and there is limited evidence to guide malnutrition interventions in cirrhosis and liver transplantation. In this review, we seek to detail the factors which contribute to poor nutritional status in liver disease, and highlight complexities far greater than "poor appetite" or "reduced oral intake" leading to malnutrition. We also discuss management strategies to optimise nutritional status in this patient group, which target the inter-related mechanisms unique to advanced liver disease. Finally, future research requirements are suggested, to develop effective treatments for one of the most common and debilitating complications afflicting cirrhotic patients.

Intravenous supplementation type and volume are associated with 1-year outcome and major complications in patients with chronic intestinal failure

BACKGROUND AND AIM

No marker to categorise the severity of chronic intestinal failure (CIF) has been developed. A 1-year international survey was carried out to investigate whether the European Society for Clinical Nutrition and Metabolism clinical classification of CIF, based on the type and volume of the intravenous supplementation (IVS), could be an indicator of CIF severity.

METHODS

At baseline, participating home parenteral nutrition (HPN) centres enrolled all adults with ongoing CIF due to non-malignant disease; demographic data, body mass index, CIF mechanism, underlying disease, HPN duration and IVS category were recorded for each patient. The type of IVS was classified as fluid and electrolyte alone (FE) or parenteral nutrition admixture (PN). The mean daily IVS volume, calculated on a weekly basis, was categorised as <1, 1-2, 2-3 and >3 L/day. The severity of CIF was determined by patient outcome (still on HPN, weaned from HPN, deceased) and the occurrence of major HPN/CIF-related complications: intestinal failure-associated liver disease (IFALD), catheter-related venous thrombosis and catheter-related bloodstream infection (CRBSI).

RESULTS

Fifty-one HPN centres included 2194 patients. The analysis showed that both IVS type and volume were independently associated with the odds of weaning from HPN (significantly higher for PN <1 L/day than for FE and all PN >1 L/day), patients' death (lower for FE, p=0.079), presence of IFALD cholestasis/liver failure and occurrence of CRBSI (significantly higher for PN 2-3 and PN >3 L/day).

CONCLUSIONS

The type and volume of IVS required by patients with CIF could be indicators to categorise the severity of CIF in both clinical practice and research protocols.

Impact of nutritional status/risk and post-operative nutritional management on clinical outcomes in patients undergoing gastrointestinal surgery: a prospective observational study

BACKGROUND

Malnutrition is prevalent in patients undergoing gastrointestinal (GI) surgery and has been linked to adverse outcomes. The present study aimed to determine the association between early post-operative nutritional status/risk, post-operative nutritional management and clinical outcomes.

METHODS

A prospective observational study was conducted in GI surgical patients with a minimum 3-day post-operative length of stay (LOS). Data on patient demographics, nutritional status/risk, post-operative nutritional management and clinical outcomes were collected. Four markers of nutritional status and risk were assessed: preoperative weight loss, nutrition risk, malnutrition status and hand grip strength. Clinical outcomes included: post-operative LOS, complication and readmissions rates. Multivariate linear and logistic regression were used to test for associations with clinical outcomes.

RESULTS

One hundred and fifteen patients (55% female) with mean (SD) age of 60.8 (16.2) years were included. Median (IQR) post-operative LOS was 8.0 days (4.5-11.5), 37% of participants developed at least one complication post-operatively and 24% were readmitted within 30-days of discharge. Mean number of nil-by mouth (NBM) days post-operatively was 0.7 (1.2) and the average time to commence feeding was 3.3 (2.2) days after surgery. Poor nutritional status/risk between days 3-5 post-operatively assessed through all four markers was associated with longer post-operative LOS (all P < 0.05). No association was found between number of NBM days, time to feeding and clinical outcomes.

CONCLUSION

Poor early post-operative nutritional status/risk is associated with longer post-operative LOS in patients undergoing GI surgery, which may facilitate simple identification of patients at high priority for nutritional intervention. The present study highlights the heterogeneity in post-operative nutritional management practices.

Handgrip Strength Adds More Prognostic Value to the Model for End-Stage Liver Disease Score Than Imaging-Based Measures of Muscle Mass in Men With Cirrhosis

Sarcopenia is associated with mortality in cirrhosis, but there is no gold standard for its diagnosis. The comparative utility of different diagnostic methods is unknown. This single-center observational cohort study followed 145 men referred for liver transplant evaluation between 2005 and 2012. Muscle mass was estimated by handgrip strength, dual energy X-ray absorptiometry (DEXA) lean mass, and single-slice computed tomography (CT) scan at the fourth lumbar vertebra. Recorded outcomes included time to death or liver transplantation. The median (interquartile range [IQR]) age was 54 years (47-59 years), and Model for End-Stage Liver Disease (MELD) score was 17 (14-23). Of 145 men, 56 died with a median (IQR) time to death of 7.44 months (3.48-14.16 months). In total, 79 men underwent transplantation with median (IQR) time to transplant of 7.20 months (3.96-12.84 months). The prevalence of sarcopenia differed between diagnostic modalities with 70.3% using CT muscle mass, 45.9% using handgrip strength, and 38.7% using DEXA. Muscle mass was inversely associated with wait-list mortality for measured CT muscle mass (hazard ratio [HR], 0.94; 95% confidence interval (CI), 0.90-0.98; P = 0.002), DEXA muscle mass (HR, 0.99; 95% CI, 0.99-0.99; P = 0.003), and handgrip strength (HR, 0.94; 95% CI, 0.91-0.98; P = 0.002). These results retained significance independent of the MELD score. In predicting mortality, the MELD-handgrip strength bivariate Cox model was superior to a MELD-CT muscle Cox model (P < 0.001). In conclusion, handgrip strength combined with MELD score was the superior predictive model in this novel study examining 3 commonly employed techniques to diagnose sarcopenia in cirrhosis. Handgrip strength has additional potential clinical benefits because it can be performed serially without the radiation dose, cost, and access issues attributable to CT and DEXA.

Use of Dual X-ray Absorptiometry in men with advanced cirrhosis to predict sarcopenia-associated mortality risk

INTRODUCTION

Reduced muscle area on CT scan is an independent predictor of mortality in cirrhosis. We examine for the first time the relationship between dual energy x-ray absorptiometry (DEXA) lean mass parameters on outcomes in cirrhotic men awaiting liver transplantation.

MATERIALS AND METHODS

We retrospectively reviewed DEXA scans performed during transplant assessment between 2001 and 2016. Baseline data including the presence of ascites and MELD score were recorded. DEXA lean mass measures were adjusted for height. The primary outcome was 12-month wait-list mortality.

RESULTS

Four hundred twenty men with median age 55.4 years [interquartile range 49.2; 59.4] and MELD 16 [12; 20] were studied. Median follow-up was 58.5 [28.8; 109] months. 12-month wait-list mortality was 12.4%. Appendicular lean mass was inversely associated with mortality (HR 0.78 [0.62; 0.98], P = 0.03). Lean mass of arms (HR 0.37 [0.16; 0.83], P  = 0.02) rather than legs (HR 0.77 [0.58; 1.03], P  = 0.08) was responsible for this association. Upper limb lean mass showed a significant interaction with MELD score in predicting wait-list mortality, particularly within 4 months. Total lean mass was not associated with mortality but increased in conjunction with increasing ascites (OR for ascites 1.20 [1.15; 1.25], P < 0.001 for each unit increase in MELD).

CONCLUSION

Upper limb lean mass by DEXA is strongly associated with mortality in men awaiting liver transplantation. The superiority of upper limb lean mass probably relates to confounding of lower limb measures by fluid retention. This DEXA parameter represents a novel and reproducible measure of sarcopenia in cirrhosis.

Candidaemia and a risk predictive model for overall mortality: a prospective multicentre study

Background

Candidaemia is associated with high mortality. Variables associated with mortality have been published previously, but not developed into a risk predictive model for mortality. We sought to describe the current epidemiology of candidaemia in Australia, analyse predictors of 30-day all-cause mortality, and develop and validate a mortality risk predictive model.

Methods

Adults with candidaemia were studied prospectively over 12 months at eight institutions. Clinical and laboratory variables at time of blood culture-positivity were subject to multivariate analysis for association with 30-day all-cause mortality. A predictive score for mortality was examined by area under receiver operator characteristic curves and a historical data set was used for validation.

Results

The median age of 133 patients with candidaemia was 62 years; 76 (57%) were male and 57 (43%) were female. Co-morbidities included underlying haematologic malignancy (n = 20; 15%), and solid organ malignancy in (n = 25; 19%); 55 (41%) were in an intensive care unit (ICU). Non-albicans Candida spp. accounted for 61% of cases (81/133). All-cause 30-day mortality was 31%. A gastrointestinal or unknown source was associated with higher overall mortality than an intravascular or urologic source (p < 0.01). A risk predictive score based on age > 65 years, ICU admission, chronic organ dysfunction, preceding surgery within 30 days, haematological malignancy, source of candidaemia and antibiotic therapy for ≥10 days stratified patients into < 20% or ≥ 20% predicted mortality. The model retained accuracy when validated against a historical dataset (n = 741).

Conclusions

Mortality in patients with candidaemia remains high. A simple mortality risk predictive score stratifying patients with candidaemia into < 20% and ≥ 20% 30-day mortality is presented. This model uses information available at time of candidaemia diagnosis is easy to incorporate into decision support systems. Further validation of this model is warranted.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4065-5) contains supplementary material, which is available to authorized users.

Continuous terlipressin infusion is associated with improved diet intake and muscle strength in patients awaiting liver transplant

Background & Aims

Portal hypertension contributes to the pathogenesis of malnutrition and sarcopenia in cirrhosis via multiple mechanisms. Terlipressin is a vasopressin analogue that we administer via continuous outpatient infusion, as a bridge to transplantation in patients with hepatorenal syndrome or refractory ascites. We describe, for the first time, the impact of outpatient terlipressin on nutritional and muscle parameters.

Methods

Nutrition (subjective global assessment), handgrip strength, dietary intake (energy, protein), frequency of paracentesis and severity of liver disease (model for end-stage liver disease score) were prospectively recorded at terlipressin commencement and follow-up (transplantation, cessation or census date).

Results

Nineteen patients were included (89% male, median age 59.6 years, median model for end-stage liver disease score 24), of whom 12 had hepatorenal syndrome and 7 had refractory ascites. All patients were malnourished at baseline, 63% (n = 12) had sarcopenic-range grip strength, and mean paracentesis frequency was 2.86 ± 1.62/month. Median duration of terlipressin was 51 days (interquartile range 29–222). Fourteen patients (74%) were transplanted, 2 delisted (10%) and 3 (16%) continued terlipressin. Energy and protein intake improved significantly following terlipressin, from 17.94 ± 5.43 kcal/kg to 27.70 ± 7.48 kcal/kg, and 0.74 ± 0.28 g/kg to 1.16 ± 0.31 g/kg, respectively (both p < 0.001). Handgrip strength increased from 25.36 ± 8.13 kg to 28.49 ± 7.63 kg (p = 0.001). Linear regression analysis demonstrated hand grip strength increased 0.075% for every 1-day of terlipressin (p = 0.005). The frequency of large-volume paracentesis reduced by 46%, to 1.57 ± 1.51/month (p = 0.001).

Conclusion

Continuous terlipressin infusion reduces the complications of portal hypertension and is associated with an improvement in nutritional and muscle parameters in patients on the liver transplant waiting list, in whom such characteristics usually demonstrate progressive decline. This validates both the aetiological role of portal hypertension in malnutrition and represents a promising new anabolic therapy.

Lay summary

Malnutrition and poor muscle strength are common in liver disease and often get worse while patients await liver transplant. Terlipressin is a medication used to treat portal hypertension in patients with hepatorenal syndrome. It is usually given for a few days or weeks in patients confined to hospital. Our centre provides outpatient terlipressin for weeks to months as a bridge to liver transplant. In patients treated with terlipressin at our hospital, we observed a substantial increase in their dietary intake and muscle strength, which may improve their quality of life and outcomes after liver transplant.

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Malnutrition and poor muscle strength are highly prevalent in cirrhotics with hepatorenal syndrome.

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Terlipressin infusion increased energy and protein intake in patients with hepatorenal syndrome.

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Handgrip strength continued to increase with every day of terlipressin therapy

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Medium to long-term terlipressin infusion was safe and efficacious as a bridge to liver transplant.

The role of citizen science in addressing grand challenges in food and agriculture research

The power of citizen science to contribute to both science and society is gaining increased recognition, particularly in physics and biology. Although there is a long history of public engagement in agriculture and food science, the term 'citizen science' has rarely been applied to these efforts. Similarly, in the emerging field of citizen science, most new citizen science projects do not focus on food or agriculture. Here, we convened thought leaders from a broad range of fields related to citizen science, agriculture, and food science to highlight key opportunities for bridging these overlapping yet disconnected communities/fields and identify ways to leverage their respective strengths. Specifically, we show that (i) citizen science projects are addressing many grand challenges facing our food systems, as outlined by the United States National Institute of Food and Agriculture, as well as broader Sustainable Development Goals set by the United Nations Development Programme, (ii) there exist emerging opportunities and unique challenges for citizen science in agriculture/food research, and (iii) the greatest opportunities for the development of citizen science projects in agriculture and food science will be gained by using the existing infrastructure and tools of Extension programmes and through the engagement of urban communities. Further, we argue there is no better time to foster greater collaboration between these fields given the trend of shrinking Extension programmes, the increasing need to apply innovative solutions to address rising demands on agricultural systems, and the exponential growth of the field of citizen science.

Observations of core ion cyclotron emission on ASDEX Upgrade tokamak

The B-dot probe diagnostic suite on the ASDEX Upgrade tokamak has recently been upgraded with a new 125 MHz, 14 bit resolution digitizer to study ion cyclotron emission (ICE). While classic edge emission from the low field side plasma is often observed, we also measure waves originating from the core with fast fusion protons or beam injected deuterons being a possible emission driver. Comparing the measured frequency values with ion cyclotron harmonics present in the plasma places the origin of this emission on the magnetic axis, with the fundamental hydrogen/second deuterium cyclotron harmonic matching the observed values. The actual values range from ∼27 MHz at the on-axis toroidal field B_T = -1.79 T to ∼40 MHz at B_T = -2.62 T. When the magnetic axis position evolves during this emission, the measured frequency values track the changes in the estimated on-axis cyclotron frequency values. Core ICE is usually a transient event lasting ∼100 ms during the neutral beam startup phase. However, in some cases, core emission occurs in steady-state plasmas and lasts for longer than 1 s. These observations suggest an attractive possibility of using a non-perturbing ICE-based diagnostic to passively monitor fusion alpha particles at the location of their birth in the plasma core, in deuterium-tritium burning devices such as ITER and DEMO.

Multi-Exposure Pathway Model to Compare Escherichia coli O157 Risks and Interventions

The relative contributions of exposure pathways associated with cattle-manure-borne Escherichia coli O157:H7 on public health have yet to be fully characterized. A stochastic, quantitative microbial risk assessment (QMRA) model was developed to describe a hypothetical cattle farm in order to compare the relative importance of five routes of exposure, including aquatic recreation downstream of the farm, consumption of contaminated ground beef processed with limited interventions, consumption of leafy greens, direct animal contact, and the recreational use of a cattle pasture. To accommodate diverse environmental and hydrological pathways, existing QMRAs were integrated with novel and simplistic climate and field-level submodels. The model indicated that direct animal contact presents the greatest risk of illness per exposure event during the high pathogen shedding period. However, when accounting for the frequency of exposure, using a high-risk exposure-receptor profile, consumption of ground beef was associated with the greatest risk of illness. Additionally, the model was used to evaluate the efficacy of hypothetical interventions affecting one or more exposure routes; concurrent evaluation of multiple routes allowed for the assessment of the combined effect of preharvest interventions across exposure pathways-which may have been previously underestimated-as well as the assessment of the effect of additional downstream interventions. This analysis represents a step towards a full evaluation of the risks associated with multiple exposure pathways; future incorporation of variability associated with environmental parameters and human behaviors would allow for a comprehensive assessment of the relative contribution of exposure pathways at the population level.

Clinical classification of adult patients with chronic intestinal failure due to benign disease: An international multicenter cross-sectional survey

BACKGROUND & AIMS

The aim of the study was to evaluate the applicability of the ESPEN 16-category clinical classification of chronic intestinal failure, based on patients' intravenous supplementation (IVS) requirements for energy and fluids, and to evaluate factors associated with those requirements.

METHODS

ESPEN members were invited to participate through ESPEN Council representatives. Participating centers enrolled adult patients requiring home parenteral nutrition for chronic intestinal failure on March 1st 2015. The following patient data were recorded though a structured database: sex, age, body weight and height, intestinal failure mechanism, underlying disease, IVS volume and energy need.

RESULTS

Sixty-five centers from 22 countries enrolled 2919 patients with benign disease. One half of the patients were distributed in 3 categories of the ESPEN clinical classification. 9% of patients required only fluid and electrolyte supplementation. IVS requirement varied considerably according to the pathophysiological mechanism of intestinal failure. Notably, IVS volume requirement represented loss of intestinal function better than IVS energy requirement. A simplified 8 category classification of chronic intestinal failure was devised, based on two types of IVS (either fluid and electrolyte alone or parenteral nutrition admixture containing energy) and four categories of volume.

CONCLUSIONS

Patients' IVS requirements varied widely, supporting the need for a tool to homogenize patient categorization. This study has devised a novel, simplified eight category IVS classification for chronic intestinal failure that will prove useful in both the clinical and research setting when applied together with the underlying pathophysiological mechanism of the patient's intestinal failure.

Intestinal Failure and Transplant: The Australian Experience (2009 to 2014)

BACKGROUND

A joint adult and pediatric intestinal transplant (ITx) program for Australia was developed in 2009 to provide life-saving ITx to patients with irreversible intestinal failure (IF). We aimed to analyze the outcomes of patients treated by our service over the past 5 years.

METHODS

A retrospective medical record review was conducted on all IF patients referred to our service. Patient demographics, underlying disease, nutrition support, TPN complications, and current transplant program status were evaluated.

RESULTS

Fifty-seven patients (35 adults, 40.4 ± 12.4 years; 22 children, 6.3 ± 4.3 years) throughout Australia and New Zealand have been referred. Leading causes of IF were short bowel syndrome followed by pseudo-obstruction. Forty patients (70%) exhibited at least 1 life-threatening complication of PN at referral: liver failure, impending loss of venous access, and/or recurrent line sepsis. Three patients have undergone ITx with 100% survival (median follow-up, 1161 days). Four patients (8%) are listed for transplant, 6 patients (12%) are awaiting transplant assessment, and 4 patients (8%) have died (2 while awaiting transplantation, 2 during assessment period). Causes of death included sepsis and intracranial bleed. Two-thirds of all referred patients (n = 40) were deferred or rejected from wait-listing.

CONCLUSIONS

After 5 years of establishing the first dedicated ITx program in Australia and New Zealand, early results indicate that ITx is an available and life-saving option for IF patients in these countries. Current barriers to ITx in Australia include a shortage of appropriate donors and a high rate of donor-specific antibodies among potential recipients. Growing awareness of the service and early referral to assist appropriate patient selection will aid in the program's success.

Mucormycosis in Australia: contemporary epidemiology and outcomes

Mucormycosis is the second most common cause of invasive mould infection and causes disease in diverse hosts, including those who are immuno-competent. We conducted a multicentre retrospective study of proven and probable cases of mucormycosis diagnosed between 2004-2012 to determine the epidemiology and outcome determinants in Australia. Seventy-four cases were identified (63 proven, 11 probable). The majority (54.1%) were caused by Rhizopus spp. Patients who sustained trauma were more likely to have non-Rhizopus infections relative to patients without trauma (OR 9.0, p 0.001, 95% CI 2.1-42.8). Haematological malignancy (48.6%), chemotherapy (42.9%), corticosteroids (52.7%), diabetes mellitus (27%) and trauma (22.9%) were the most common co-morbidities or risk factors. Rheumatological/autoimmune disorders occurred in nine (12.1%) instances. Eight (10.8%) cases had no underlying co-morbidity and were more likely to have associated trauma (7/8; 87.5% versus 10/66; 15.2%; p <0.001). Disseminated infection was common (39.2%). Apophysomyces spp. and Saksenaea spp. caused infection in immuno-competent hosts, most frequently associated with trauma and affected sites other than lung and sinuses. The 180-day mortality was 56.7%. The strongest predictors of mortality were rheumatological/autoimmune disorder (OR = 24.0, p 0.038 95% CI 1.2-481.4), haematological malignancy (OR = 7.7, p 0.001, 95% CI 2.3-25.2) and admission to intensive care unit (OR = 4.2, p 0.02, 95% CI 1.3-13.8). Most deaths occurred within one month. Thereafter we observed divergence in survival between the haematological and non-haematological populations (p 0.006). The mortality of mucormycosis remains particularly high in the immuno-compromised host. Underlying rheumatological/autoimmune disorders are a previously under-appreciated risk for infection and poor outcome.

Profiling cancer gene mutations in longitudinal epithelial ovarian cancer biopsies by targeted next-generation sequencing: a retrospective study

BACKGROUND

The majority of patients with stage III-IV epithelial ovarian cancer (EOC) relapse after initially responding to platinum-based chemotherapy, and develop resistance. The genomic features involved in drug resistance are unknown. To unravel some of these features, we investigated the mutational profile of genes involved in pathways related to drug sensitivity in a cohort of matched tumors obtained at first surgery (Ft-S) and second surgery (Sd-S).

PATIENTS AND METHODS

Matched biopsies (33) taken at Ft-S and Sd-S were selected from the 'Pandora' tumor tissue collection. DNA libraries for 65 genes were generated using the TruSeq Custom Amplicon kit and sequenced on MiSeq (Illumina). Data were analyzed using a high-performance cluster computing platform (Cloud4CARE project) and independently validated.

RESULTS

A total of 2270 somatic mutations were identified (89.85% base substitutions 8.19% indels, and 1.92% unknown). Homologous recombination (HR) genes and TP53 were mutated in the majority of Ft-S, while ATM, ATR, TOP2A and TOP2B were mutated in the entire dataset. Only 2% of mutations were conserved between matched Ft-S and Sd-S. Mutations detected at second surgery clustered patients in two groups characterized by different mutational profiles in genes associated with HR, PI3K, miRNA biogenesis and signal transduction.

CONCLUSIONS

There was a low level of concordance between Ft-S and Sd-S in terms of mutations in genes involved in key processes of tumor growth and drug resistance. This result suggests the importance of future longitudinal analyses to improve the clinical management of relapsed EOC.

Sleep characteristics in Goldenhar Syndrome

OBJECTIVE

To examine the characteristics of sleep in patients with Goldenhar Syndrome.

DESIGN

Retrospective review of all polysomnography studies conducted at the University of North Carolina Hospitals between 2003 and 2013 on patients carrying the diagnosis of Goldenhar's Syndrome.

RESULTS

A preponderance of patients demonstrated severe obstructive sleep apnea and hypercapnia.

CONCLUSIONS

Patients with Goldenhar Syndrome should be screened for sleep apnea and hypercapnia.

Observation of public health risk behaviours, risk communication and hand hygiene at Kansas and Missouri petting zoos--2010-2011

Outbreaks of human illness have been linked to visiting settings with animal contact throughout developed countries. This study details an observational study of hand hygiene tool availability and recommendations; frequency of risky behaviour; and handwashing attempts by visitors in Kansas (9) and Missouri (4), USA, petting zoos. Handwashing signs and hand hygiene stations were available at the exit of animal-contact areas in 10/13 and 8/13 petting zoos, respectively. Risky behaviours were observed being performed at all petting zoos by at least one visitor. Frequently observed behaviours were as follows: children (10/13 petting zoos) and adults (9/13 petting zoos) touching hands to face within animal-contact areas; animals licking children's and adults' hands (7/13 and 4/13 petting zoos, respectively); and children and adults drinking within animal-contact areas (5/13 petting zoos each). Of 574 visitors observed for hand hygiene when exiting animal-contact areas, 37% (n = 214) of individuals attempted some type of hand hygiene, with male adults, female adults and children attempting at similar rates (32%, 40% and 37%, respectively). Visitors were 4.8× more likely to wash their hands when a staff member was present within or at the exit to the animal-contact area (136/231, 59%) than when no staff member was present (78/343, 23%; P < 0.001, OR = 4.863, 95% CI = 3.380-6.998). Visitors at zoos with a fence as a partial barrier to human-animal contact were 2.3× more likely to wash their hands (188/460, 40.9%) than visitors allowed to enter the animals' yard for contact (26/114, 22.8%; P < 0.001, OR = 2.339, 95% CI = 1.454-3.763). Inconsistencies existed in tool availability, signage and supervision of animal contact. Risk communication was poor, with few petting zoos outlining risks associated with animal contact, or providing recommendations for precautions to be taken to reduce these risks.

Interactions between intracellular calcium and phosphate in intact mouse muscle during fatigue

Fatigue was studied in intact tibialis anterior muscle of anesthetized mice. The distal tendon was detached and connected to a force transducer while blood flow continued normally. The muscle was stimulated with electrodes applied directly to the muscle surface and fatigued by repeated (1 per 4 s), brief (0.4 s), maximal (100-Hz stimulation frequency) tetani. Force declined monotonically to 49 ± 5% of the initial value with a half time of 36 ± 5 s and recovered to 86 ± 4% after 4 min. Intracellular phosphate concentration ([Pi]) was measured by 31P-NMR on perchloric acid extracts of muscles. [Pi] increased during fatigue from 7.6 ± 1.7 to 16.0 ± 1.6 mmol/kg muscle wet wt and returned to control during recovery. Intracellular Ca2+ was measured with cameleons whose plasmids had been transfected in the muscle 2 wk before the experiment. Yellow cameleon 2 was used to measure myoplasmic Ca2+, and D1ER was used to measure sarcoplasmic reticulum (SR) Ca2+. The myoplasmic Ca2+ during tetani declined steadily during the period of fatigue and showed complete recovery over 4 min. The SR Ca2+ also declined monotonically during fatigue and showed a partial recovery with rest. These results show that the initial phase of force decline is accompanied by a rise in [Pi] and a reduction in the tetanic myoplasmic Ca2+. We suggest that both changes contribute to the fatigue. A likely cause of the decline in tetanic myoplasmic Ca2+ is precipitation of CaPi in the SR.

Contemporary formulation and distribution practices for cold-filled acid products: Australian industry survey and modeling of published pathogen inactivation data

A survey of 12 Australian manufacturers indicated that mild-tasting acids and preservatives are used to partially replace acetic acid in cold-filled acid dressings and sauces. In contrast to traditional ambient temperature distribution practices, some manufacturers indicated that they supply the food service sector with cold-filled acid products prechilled for incorporation into ready-to-eat foods. The Comité des Industries des Mayonnaises et Sauces Condimentaires de la Communauté Economique Européenne (CIMSCEE) Code, a formulation guideline used by the industry to predict the safety of cold-filled acid formulations with respect to Salmonella enterica and Escherichia coli, does not extend to the use of acids and preservatives other than acetic acid nor does it consider the effects of chill distribution. We found insufficient data in the published literature to comprehensively model the response of S. enterica and E. coli to all of the predictor variables (i.e., pH, acetic acid, NaCl, sugars, other acids, preservatives, and storage temperature) of relevance for contemporary cold-filled acid products in Australia. In particular, we noted a lack of inactivation data for S. enterica at aqueous-phase NaCl concentrations of >3% (wt/wt). However, our simple models clearly identified pH and 1/absolute temperature of storage as the most important variables generally determining inactivation. To develop robust models to predict the effect of contemporary formulation and storage variables on product safety, additional empirical data are required. Until such models are available, our results support challenge testing of cold-filled acid products to ascertain their safety, as suggested by the CIMSCEE, but suggest consideration of challenging with both E. coli and S. enterica at incubation temperatures relevant to intended product distribution temperatures.

Development of a log-quadratic model to describe microbial inactivation, illustrated by thermal inactivation of Clostridium botulinum

In the commercial food industry, demonstration of microbiological safety and thermal process equivalence often involves a mathematical framework that assumes log-linear inactivation kinetics and invokes concepts of decimal reduction time (D(T)), z values, and accumulated lethality. However, many microbes, particularly spores, exhibit inactivation kinetics that are not log linear. This has led to alternative modeling approaches, such as the biphasic and Weibull models, that relax strong log-linear assumptions. Using a statistical framework, we developed a novel log-quadratic model, which approximates the biphasic and Weibull models and provides additional physiological interpretability. As a statistical linear model, the log-quadratic model is relatively simple to fit and straightforwardly provides confidence intervals for its fitted values. It allows a D(T)-like value to be derived, even from data that exhibit obvious "tailing." We also showed how existing models of non-log-linear microbial inactivation, such as the Weibull model, can fit into a statistical linear model framework that dramatically simplifies their solution. We applied the log-quadratic model to thermal inactivation data for the spore-forming bacterium Clostridium botulinum and evaluated its merits compared with those of popular previously described approaches. The log-quadratic model was used as the basis of a secondary model that can capture the dependence of microbial inactivation kinetics on temperature. This model, in turn, was linked to models of spore inactivation of Sapru et al. and Rodriguez et al. that posit different physiological states for spores within a population. We believe that the log-quadratic model provides a useful framework in which to test vitalistic and mechanistic hypotheses of inactivation by thermal and other processes.

Escherichia coli and Salmonella enterica are protected against acetic acid, but not hydrochloric acid, by hypertonicity

Chapman et al. (B. Chapman, N. Jensen, T Ross, and M. B. Cole, Appl. Environ. Microbiol. 72:5165-5172, 2006) demonstrated that an increased NaCl concentration prolongs survival of Escherichia coli O157 SERL 2 in a broth model simulating the aqueous phase of a food dressing or sauce containing acetic acid. We examined the responses of five other E. coli strains and four Salmonella enterica strains to increasing concentrations of NaCl under conditions of lethal acidity and observed that the average "lag" time prior to inactivation decreases in the presence of hydrochloric acid but not in the presence of acetic acid. For E. coli in the presence of acetic acid, the lag time increased with increasing NaCl concentrations up to 2 to 4% at pH 4.0, up to 4 to 6% at pH 3.8, and up to 4 to 7% (wt/wt of water) NaCl at pH 3.6. Salmonella was inactivated more rapidly by combined acetic acid and NaCl stresses than E. coli, but increasing NaCl concentrations still decreased the lag time prior to inactivation in the presence of acetic acid; at pH 4.0 up to 1 to 4% NaCl was protective, and at pH 3.8 up to 1 to 2% NaCl delayed the onset of inactivation. Sublethal injury kinetics suggest that this complex response is a balance between the lethal effects of acetic acid, against which NaCl is apparently protective, and the lethal effects of the NaCl itself. Compared against 3% NaCl, 10% (wt/wt of water) sucrose with 0.5% NaCl (which has similar osmotic potential) was found to be equally protective against adverse acetic acid conditions. We propose that hypertonicity may directly affect the rate of diffusion of acetic acid into cells and hence cell survival.

Synergistic inactivation of spores of proteolytic Clostridium botulinum strains by high pressure and heat is strain and product dependent

The combined high pressure and heat resistances of spores of five proteolytic Clostridium botulinum strains and of the nonpathogenic surrogate strain Clostridium sporogenes PA3679 were compared with their heat-only resistances on the basis of equivalent accumulated thermal lethality, expressed as equivalent minutes at a reference temperature of 105 degrees C (F(105 degrees C). Comparisons were made with three model (i.e., diluted) products, namely, 30% (wt/wt) Bolognese sauce, 50% (wt/wt) cream sauce, and rice water agar. Pressure was determined to act synergistically with heat during high-pressure thermal (HPT) processing for C. botulinum FRRB 2802 (NCTC 7273) and C. botulinum FRRB 2804 (NCTC 3805 and 62A) in the Bolognese and cream sauces and for C. botulinum FRRB 2807 (213B) in the Bolognese sauce only. No synergy was observed for C. botulinum FRRB 2803 (NCTC 2916) or FRRB 2806 (62A) or C. sporogenes FRRB 2790 (NCTC 8594 and PA3679) in any of the model products. No significant protective effect of pressure against spore inactivation was determined for any Clostridium strain in any product. Because synergy was not consistently observed among strains of C. botulinum or among products, the prediction of inactivation of C. botulinum spores by HPT sterilization (HPTS) for the present must assume a complete lack of synergy. Therefore, any HPTS process for low-acid shelf-stable foods must be at least thermally equivalent to an F(0) process of 2.8 min, in line with current good manufacturing practices. The results of this study suggest that the use of C. sporogenes PA3679 as a surrogate organism may risk overestimating inactivation of C. botulinum by HPT processing.

Model gradient coil employing active acoustic control for MRI

Results are presented for a model three-axis gradient coil incorporating active acoustic control which is applied to the switched read gradient during a single-shot rapid echo-planar imaging (EPI) sequence at a field strength of 3.0 T. The total imaging acquisition time was 10.6 ms. Substantial noise reduction is achieved both within the magnet bore and outside the magnet. Typical internal noise reduction over the specimen area is 40 dB_A whereas outside the acoustic chamber the noise level is reduced by 60–77 dB_A. However these results are relative to a control winding which is switched in phase, adding 6 dB_A in its non-optimized mode, which is included in the quoted figures.

Salt, alone or in combination with sucrose, can improve the survival of Escherichia coli O157 (SERL 2) in model acidic sauces

The commercial production of microbiologically safe and stable sauces containing acetic acid is guided by the Comité des Industries des Mayonnaises et Sauces Condimentaires de la Communauté Economique Européenne's (CIMSCEE) code. The CIMSCEE safety value is calculated using a linear regression equation combining weighted contributions of pH and aqueous-phase concentrations of undissociated acetic acid, NaCl, and sugars. By implication, the CIMSCEE safety equation predicts that increasing concentrations of hurdles will always increase inactivation of the target pathogen. In this study, the time to achieve a 3-log10 reduction of an acid-resistant, acid-adapted, Shiga toxin-producing Escherichia coli (STEC) O157 isolate was determined experimentally for 81 formulations at various pHs and acetic acid, NaCl, and sucrose concentrations in a broth model. The combinations were intended to simulate the aqueous phase of acidic sauces and dressings. Experimental data were fitted to the log logistic model to estimate the time to 3-log10 reduction (t3D). Comparison of fitted t3D estimates with CIMSCEE values showed agreement in predicting safety (as defined by CIMSCEE) for the majority of formulations. However, CIMSCEE safety predictions were "fail dangerous" for 13 of 81 formulations. Among these formulations and others, the observed E. coli t3D initially increased and then decreased with increasing osmolalities (NaCl and sucrose). Relative protection increased with exposure time where the protective effect of NaCl predominated. While commercial acidic sauces are not considered high-risk vehicles for STEC, interactions among hurdles that decrease their combined effectiveness are deserving of further investigation because they may reveal mechanisms of broader relevance in the inactivation of pathogens in foods.