Protein malnutrition after Roux-en-Y gastric bypass: a challenging case and scoping review of the literature

Although protein malnutrition (PM) is often reported after highly malabsorptive procedures, its exact incidence and mechanisms after Roux-en-Y gastric bypass (RYGB) are poorly understood. The aim of this study was to present a challenging clinical case of PM after RYGB and conduct a scoping review of the literature. Among the 18 studies with 3015 RYGB patients included in the review, the median incidence of PM was 1.7% (range, 0%-8.9%), and it was diagnosed 12 to 120 months after RYGB. The most common cause is insufficient oral intake of protein; however, in cases of persistent hypoalbuminemia, a thorough diagnostic workup needs to be performed. Risk factors for PM after RYGB include specific triggering events such as intractable vomiting and dysphagia, and a total alimentary limb length less than 250 to 300 cm.

Predictive value of multiple variable models including nutritional risk score (NRS 2002) on mortality and length of stay of patients with covid-19 infections. The INCOVO study

BACKGROUND AND AIMS

This study aimed at evaluating associations between nutritional status and outcomes in patients with Covid-19 and to identify statistical models including nutritional parameters associated with in-hospital mortality and length of stay.

METHODS

Data of 5707 adult patients hospitalized in the University Hospital of Lausanne between March 2020 and March 2021 were screened retrospectively 920 patients (35% female) with confirmed Covid-19 and complete data including nutritional risk score (NRS 2002), were included. This cohort was divided into three subgroups: NRS <3: no risk of malnutrition; NRS ≥3 to <5: moderate risk malnutrition; and NRS ≥5: severe risk of malnutrition. The primary outcome was the percentage of in-hospital deaths in the different NRS subgroups. The secondary outcomes were the length of hospital stay (LOS), the percentage of admissions to intensive care units (ICU), and the length of stay in the ICU (ILOS). Logistic regression was performed to identify risk factors associated with in-hospital mortality and hospital stay. Multivariate clinical-biological models were developed to study predictions of mortality and very long length of stay.

RESULTS

The mean age of the cohort was 69.7 years. The death rate was 4 times higher in the subgroup with a NRS ≥ 5 (44%), and 3 times higher with a NRS ≥ 3 to <5 (33%) compared to the patients with a NRS<3 (10%) (p < 0.001). LOS was significantly higher in the NRS ≥ 5 and NRS ≥ 3 to <5 subgroups (26.0 days; CI [21; 30.9]; and 24.9; CI [22.5; 27.1] respectively) versus 13.4; CI [12; 14.8] for NRS<3 (p < 0.001). The mean ILOS was significantly higher in the NRS ≥ 5 (5.9 days; versus 2.8 for NRS ≥ 3 to <5, and 1.58 for NRS<3 (p < 0.001)). In logistic regression, NRS ≥ 3 was significantly associated with the risk of mortality (OR: 4.8; CI [3.3; 7.1]; p < 0.001) and very long in-hospital stay (>12 days) (OR: 2.5; CI [1.9; 3.3]; p < 0.001). Statistical models that included a NRS ≥ 3 and albumin revealed to be strong predictors for mortality and LOS (area under the curve 0.800 and 0.715).

CONCLUSION

NRS was found to be an independent risk factor for in-hospital death and LOS in hospitalized Covid-19 patients. Patients with a NRS ≥ 5 had a significant increase in ILOS and mortality. Statistical models including NRS are strong predictors for an increased risk of death and LOS.

[Is ketogenic diet effective against cancer ?]

The ketogenic diet, which consists of reduced carbohydrate intake and increased fat intake, is a recognized treatment option for children with intractable epilepsy. This diet is now receiving renewed interest from physicians and researchers because of its potential therapeutic effect in other diseases, such as neurodegenerative diseases, metabolic syndrome or cancer. Since cancer is one of the major public health challenges, complementary approaches to improve the efficacy of standard anti-cancer therapies are the subject of much research. This article reviews the place of the ketogenic diet as a complementary therapy in cancer, the scientific evidence and possible practical aspects of such an approach.

[Clinical nutrition: what's new in 2022]

In 2022, the European Society of Enteral and Parenteral Nutrition (ESPEN) has released several relevant updates and guidelines. This review will highlight the key messages of three guidelines focusing on nutritional management in the geriatric population, micronutrient disorders, and sarcopenic obesity. Special emphasis will be directed towards recommendations impacting ambulatory clinical practice.

[Subclinical atherosclerosis in hypercholesterolemia - Towards a personalized, shared decision-making cardiovascular prevention]

Identification of subjects at increased cardiovascular risk (CV) using traditional risk calculators is established. Nevertheless, up to 50% of CV events occur in people classified as intermediate risk. Non-invasive atherosclerosis (ATS) assessment with carotid/femoral US and coronary artery calcium score, offers the opportunity of a personalized prevention. ATS detection could be useful in improving CV risk stratification, in optimizing individual therapeutic management and in promoting a shared decision-making process. Is this the era of a paradigm shift in CV-risk prediction? The fascinating question is still open, but the increasing number of evidences shed new insights for our everyday clinical practice. Here we strive to provide an updated scenario on the use of ATS imaging in the CV risk evaluation and therapeutic decision.

[New trends in non-alcoholic fatty liver diseases (NAFLD)]

Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent liver diseases with an epidemiology correlated to obesity and metabolic syndrome. The last decade was rich of significant advances in understanding the pathophysiology of the disease, linking environmental elements, genetic factors and microbiota modifications, as well as in staging, screening and therapeutic development. The purpose of this article is to summarize recent advances in the field of NAFLD, on her way to become the first cause of cirrhosis and liver transplantation worldwide.

Bulk Nanobubbles from Acoustically Cavitated Aqueous Organic Solvent Mixtures

We investigate the existence and stability of bulk nanobubbles in various aqueous organic solvent mixtures. Bulk nanobubble suspensions generated via acoustic cavitation are characterized in terms of their bubble size distribution, bubble number density, and zeta potential. We show that bulk nanobubbles exist in pure water but do not exist in pure organic solvents, and they disappear at some organic solvent-water ratio. We monitor the nanobubble suspensions over a period of a few months and propose interpretations for the differences behind their long-term stability in pure water versus their long-term stability in aqueous organic solvent solutions. Bulk nanobubbles in pure water are stabilized by their substantial surface charge arising from the adsorption of hydroxyl ions produced by self-ionization of water. Pure organic solvents do not autoionize, and therefore, nanobubbles cannot exist in concentrated aqueous organic solvent solutions. Because of preferential adsorption of organic solvent molecules at the nanobubble interfaces, the surface charge of the nanobubbles decreases with the solvent content, but the strong hydrogen bonding near their interfaces ensures their stability. The mean bubble size increases monotonically with the solvent content, whereas the surface tension of the mixture is sharply reduced. This is in agreement with literature results on macro- and microbubbles in aqueous organic solutions, but it stands in stark contrast to the behavior of macro- and microbubbles in aqueous surfactant solutions.

Interpreting the interfacial and colloidal stability of bulk nanobubbles

This paper elucidates parts of the mystery behind the interfacial and colloidal stability of the novel bubble system of bulk nanobubbles. Stable bulk nanobubble suspensions have been generated in pure water using hydrodynamic cavitation in a high-pressure microfluidic device. The effects of pH adjustment, addition of different types of surfactant molecules and salts on the nanobubble suspensions have been studied. Results show that nanobubble interfaces in pure water are negatively charged, suggesting the formation of an electric double layer around the nanobubbles. It is presumed that the external electrostatic pressure created by the charged nanobubble interface, balances the internal Laplace pressure; therefore, no net diffusion of gas occurs at equilibrium and the nanobubbles are stable. Such stability increases with increasing alkalinity of the suspending medium. The addition of mono- and multi-valent salts leads to the screening of the electric double layer, hence, destabilizing the nanobubbles. Different surfactant molecules (non-ionic, anionic, cationic) affect the stability of bulk nanobubbles in different ways. Calculations based on the DLVO theory predict a stable colloidal system for bulk nanobubbles in pure water and this could be a further reason for their observed longevity. All in all, in pure water, the long-term stability of bulk nanobubbles seems to be caused by a combination of ion-stabilisation of their interface against dissolution and colloidal stability of the suspension.

On the Existence and Stability of Bulk Nanobubbles

Bulk nanobubbles are a novel type of nanoscale bubble system. Because of their extraordinary behavior, however, their existence is not widely accepted. In this paper, we shed light on the hypothesis that bulk nanobubbles do exist, they are filled with gas, and they survive for long periods of time, challenging present theories. An acoustic cavitation technique has been used to produce bulk nanobubbles in pure water in relatively large numbers approaching 10⁹ bubble·mL^-1 with a typical diameter of 100-120 nm. We provide multiple evidence that the nanoentities observed in suspension are nanobubbles given that they disappear after freezing and thawing of the suspensions, their nucleation rate depends strongly on the amount of air dissolved in water, and they gradually disappear over time. The bulk nanobubble suspensions were stable over periods of many months during which time the mean diameter remained unchanged, suggesting the absence of significant bubble coalescence, bubble breakage, or Ostwald ripening effects. Measurements suggest that these nanobubbles are negatively charged and their zeta potential does not vary over time. The presence of such a constant charge on the nanobubble surfaces is probably responsible for their stability. The effects of pH, salt, and surfactant addition on their colloidal stability are similar to those reported in the literature for solid nanoparticle suspensions, that is, nanobubbles are more stable in an alkaline medium than in an acidic one; the addition of salt to a nanobubble suspension drives the negative zeta potential toward zero, thus reducing the repulsive electrostatic forces between nanobubbles; and the addition of an anionic surfactant increases the magnitude of the negative zeta potential, thus improving nanobubble electrostatic stabilization.

Modelling and simulation of flow and agglomeration in deep veins valves using discrete multi physics

The hemodynamics in flexible deep veins valves is modelled by means of discrete multi-physics and an agglomeration algorithm is implemented to account for blood accrual in the flow. Computer simulations of a number of valves typologies are carried out. The results show that the rigidity and the length of the valve leaflets play a crucial role on both mechanical stress and stagnation in the flow. Rigid and short membranes may be inefficient in preventing blood reflux, but reduce the volume of stagnant blood potentially lowering the chances of thrombosis. Additionally, we also show that in venous valves, cell agglomeration is driven by stagnation rather than mechanical stress.

Using discrete multi-physics for detailed exploration of hydrodynamics in an in vitro colon system

We developed a mathematical model that describes the motion of viscous fluids in the partially-filled colon caused by the periodic contractions of flexible walls (peristalsis). In-vitro data are used to validate the model. The model is then used to identify two fundamental mechanisms of mass transport: the surfing mode and the pouring mode. The first mechanism is faster, but only involves the surface of the liquid. The second mechanism causes deeper mixing, and appears to be the main transport mechanism. Based on the gained understanding, we propose a series of measures that can improve the reliability of in-vitro models. The tracer in PET-like experiments, in particular, should not be injected in the first pocket, and its viscosity should be as close as possible to that of the fluid. If these conditions are not met, the dynamics of the tracer and the fluid diverge, compromising the accuracy of the in-vitro data.

Causes of secondary hypertension in the young population: A monocentric study

OBJECTIVE

To study the prevalence of different causes of hypertension in young adults referred to a hypertension center in the south west of France.

METHODS

We conducted a retrospective overview of patients younger than 40years old hospitalized consecutively in the Hypertension department of Toulouse University Hospital between 2012 and 2014. Clinical data about gender, age, anthropomorphic parameters and blood pressure measurement by 24h Ambulatory Blood Pressure Monitoring (ABPM) were recorded. Biological data concerned dosages of kalemia, renin and aldosterone in the supine or after 15min of seating. Recorded radiological examinations were renal artery ultrasound and abdominal CT scan.

RESULTS

One hundred and forty-eight detailed medical records were analyzed, 69 women and 79 men. Among the 69 women, the causes of secondary hypertension were primary aldosteronism (n=7), fibromuscular dysplasia (n=5) and renal disease (n=4). Oral contraceptives were involved in 13 women. In addition, essential hypertension concerned 40 women (58%). Among the 79 men, the causes of secondary hypertension were primary aldosteronism (n=10), fibromuscular dysplasia (n=3), left main renal artery entrapment by a diaphragmatic crura (n=2), renal disease (n=1), pheochromocytoma (n=3) and coarctation of the aorta (n=2). In addition, essential hypertension concerned 58 men (73%).

CONCLUSIONS

In our population, the prevalence of secondary hypertension is close to 33% (42% of females and 27% of males), with the following main causes: primary aldosteronism for 11.5%; fibromuscular dysplasia for 5.4%. Oral contraceptives were involved in the hypertension of 19% of the females.

Hypoglycaemia after gastric bypass: mechanisms and treatment

Hypoglycaemia after gastric bypass can be severe, but is uncommon, and is sometimes only revealed through monitoring glucose concentrations. The published literature is limited by the heterogeneity of the criteria used for diagnosis, arguing in favour of the Whipple triad with a glycaemia threshold of 55 mg/dl as the diagnostic reference. Women who lost most of their excess weight after gastric bypass, long after the surgery was performed, and who did not have diabetes before surgery are at the greatest risk. In this context, hypoglycaemia results from hyperinsulinism, which is either generated by pancreas anomalies (nesidioblastosis) and/or caused by an overstimulation of β cells by incretins, mainly glucagon-like peptide-1 (GLP-1). Glucose absorption is both accelerated and increased because of the direct communication between the gastric pouch and the jejunum. This is a post-surgical exaggeration of a natural adaptation that is seen in patients who have not undergone surgery in whom glucose is infused directly into the jejunum. There is not always a correspondence between symptoms and biological traits; however, hyperinsulinism is constant if hypoglycaemia is severe and there are neuroglucopenic symptoms. The treatment relies firstly on changes in eating habits, splitting food intake into five to six daily meals, slowing gastric emptying, reducing the glycaemic load and glycaemic index of foods, using fructose and avoiding stress at meals. Pharmacological treatment with acarbose is efficient, but other drugs still need to be validated in a greater number of subjects (insulin, glucagon, calcium channel blockers, somatostatin analogues and GLP-1 analogues). Lastly, if the surgical option has to be used, the benefits (efficient symptom relief) and the risks (weight regain, diabetes) should be weighed carefully.

Effect of postural changes on aldosterone to plasma renin ratio in patients with suspected secondary hypertension

AIMS

To study the influence of postural changes on aldosterone to renin ratio (ARR) in patients with suspected secondary hypertension and to evaluate the sensitivity and specificity of the recommended seated ARR compared to supine and upright ARR for primary aldosteronism screening.

METHODS

Fifty-three hypertensive patients were prospectively hospitalized for secondary hypertension exploration (age: 51 ± 12, 66% males). After withdrawal of drugs interfering with renin angiotensin system, plasma aldosterone and direct renin concentration were measured in the morning, at bed after an overnight supine position, then out of bed after 1 hour of upright position and finally 2 hours later after 15 minutes of seating. Minimal renin value was set at 5 μUI/mL.

RESULTS

Referring to ARR cut-off of 23 pg/μUI, the sensitivity of seated ARR was 57.1% and specificity was 92.3%. The negative and positive predictive values were 95.1% and 45.2% respectively. Compared to these results, a cut-off of 19 improved sensitivity to 85.7% with a specificity of 89.7%. Negative and positive predictive values were 98.3% and 41.1% respectively. Seated ARR mean value was lower than supine and upright ARR mean values, due to an overall increase in renin at seating compared to the supine position by factor 1.9 while aldosterone just slightly increased by factor 1.2. Seated ARR correlated to supine and upright ARR: correlation coefficients (r) 0.90 and 0.93 respectively (P<0.001).

CONCLUSIONS

Current recommended measurement of ARR in the seating position is fairly correlated to supine and upright ARR. A suggested cut-off value of 19 instead of 23 pg/μUI increased the discriminating power of this test.

Pneumatic foam generation in the presence of a high-intensity ultrasound field

Designer foams find applications in a wide range of industries. Foam quality is mostly determined by its complex cellular structure which defines its texture, rheology and stability. In addition to formulation design, the formation process is crucial to the development of a foam with an optimum structure. There is, therefore, a need for techniques that can assist in the generation of controlled foam structures. The work described in this paper demonstrates the potential of using high-intensity ultrasound to control foam structure during production. Foam generated in the presence of ultrasound usually exhibits a narrower bubble size distribution, i.e. a more uniform texture. Such enhanced homogeneity in texture is desirable to reduce the presence of aesthetically unattractive large cavities, and to reduce the destabilising effects of foam coarsening. In addition, a smaller mean bubble size and a slower rate of foam collapse usually result when ultrasound is applied. The work shows the effects on foams stabilised with different surfactants.

Foam Destabilization by Mechanical and Ultrasonic Vibrations

The need to destabilize foams and control their formation arises in many industrial applications. Vibrations are known to affect the structure and rheology of various soft solids but have not been exploited in destroying persistent foams. Being noninvasive, they offer elegant potential alternatives to chemical and mechanical foam breaking techniques. This paper reports an experimental study on the effectiveness of mechanical and ultrasonic vibrations in foam destruction. Mechanical vibration is effective at breaking static foams generated from non-Newtonian shear-thinning liquids, by enhancing liquid drainage and film breakage. Drainage is increased due to enhanced shear thinning that leads to a reduction in yield stress and shear viscosity of the nonNewtonian liquid. High intensity ultrasonic vibration is efficient at destabilizing static foams but is also effective at controlling dynamic foam heads and would be suitable for use in processes that require continuous defoaming. Destabilization of the foam films is attributed to possible squeezing mode surface wave phenomena. Copyright 1999 Academic Press.