Effect of mechanical properties on in vitro dynamic digestion of starch contained in hydrogels

BACKGROUND

This study evaluates the effect of mechanical properties on the in vitro dynamic gastrointestinal digestion of hydrogels containing starch (HCSs) as a model for studying the nutrient digestibility of solid foods. It provides a useful theoretical basis for the processing of specific foods.

RESULT

Four types of HCSs with two levels of fracture stress (17.4-20.9 kPa and 55.5-57.6 kPa) and two levels of fracture strain (25.4-28.5% and 53.7-57.4%) were prepared. For these HCSs, the degree of gastric disintegration of hydrogels reduced significantly when fracture strain exceeded 30% (P < 0.05). The gastric emptying of HCS particles was also affected by mechanical properties. For example, even at the same level of fracture stress (ca. 20 kPa), the dry solids retention ratio decreased markedly from 0.90 to 0.43 with a decrease in fracture strain from 53.7% to 25.4% (P < 0.05). For the starch hydrolysis of HCSs after gastric digestion, more than 70% of starch in the particles of all types of HCSs emptied did not undergo digestion. The starch hydrolysis of HCSs during small intestinal digestion was also influenced by their mechanical properties. Fracture strains of HCSs, rather than their fracture stress, affected starch digestibility in hydrogels.

CONCLUSION

The gastric disintegration, the gastric emptying, and the starch hydrolysis of HCSs are suppressed when fracture strain exceeded 30%. Even with the amount of nutritional components contained in hydrogels being the same, the in vitro gastrointestinal digestion behavior of HCSs depends on their mechanical properties. This behavior has the potential to be used in the design of processed foods with controlled bioaccessibility. © 2023 Society of Chemical Industry.

Cholelithiasis prevalence and risk factors in individuals with severe or profound intellectual and motor disabilities

BACKGROUND

The prevalence and risk factors of cholelithiasis in individuals with severe or profound intellectual and motor disabilities (SPIMD) are poorly characterised. Thus, we aimed to investigate the prevalence and risk determinants of cholelithiasis in a cohort with SPIMD under medical care in a residential facility.

METHODS

We categorised 84 patients in a residential hospital for persons with SPIMD into groups: those with (Group CL) and without (Group N) cholelithiasis. Gallstones were detected via computed tomography, ultrasonography or both. We evaluated gastrostomy status, nutritional and respiratory support, constipation, and bladder and kidney stones. Data were significantly analysed using univariate and multivariate logistic regression analyses.

RESULTS

The prevalence rate of cholelithiasis in our SPIMD cohort was 27%. There were no significant differences in sex, age, weight, height, or Gross Motor Function Classification System between the two groups. However, more patients received enteral nutrition (39.13% vs. 6.56%; P = 0.000751) and were on ventilator support (56.52% vs. 19.67%; P = 0.00249) in Group CL than in Group N. Enteral nutrition [odds ratio (OR) 10.4, 95% confidence interval (CI) 1.98-54.7] and ventilator support (OR 20.0, 95% CI 1.99-201.0) were identified as independent risk factors for the prevalence of cholelithiasis in patients with SPIMD.

CONCLUSIONS

Patients with SPIMD demonstrated an increased prevalence of cholelithiasis, with a notable association between nutritional tonic use and respiratory support. Therefore, to emphasise the need for proactive screening, it is crucial to devise diagnostic and therapeutic strategies specific to patients with SPIMD. Further investigation is essential to validate our findings and explore causative factors.

Intravenous vagal stimulation catheter, JOHAKU, rapidly decreases heart rate and myocardial oxygen consumption without worsening hemodynamics

Background

Rapid reduction of heart rate (HR) is the most evident physiological response of vagal nerve stimulation (VNS). Since HR reduction is the most potent factor to decrease myocardial oxygen consumption rate (MVO2), the appropriate VNS can exert cardio-protective effects. It is also known that VNS reduces inflammation, oxidative stress, and sympathetic overload. In addition, the VNS during ischemia-reperfusion is known to attenuate myocardial damage by studies in various animal species. Despite the presence of preclinical evidence of VNS benefits, the lack of the device has limited the translation of this technology to clinical practice. We have recently developed an intravenous VNS catheter (JOHAKU, Neuroceuticals Inc.) that can stimulate the right vagal nerve via superior vena cava (SVC) (Figure 1) on temporary basis.

Purpose

We aimed to confirm the feasibility of JOHAKU as a device to modulate heart rate and MVO2 rapidly by a canine experiment.

Methods

In eight beagle dogs, JOHAKU was inserted from the right femoral vein and placed at the SVC level. The stimulation intensity was adjusted to 10–20 V (20 Hz). We simultaneously recorded electrocardiogram and intraarterial blood pressure (BP). In three of eight dogs, we measured the left anterior descending coronary artery flow and oxygen saturations of arterial and coronary sinus blood to calculate MVO2. We compared HR, BP, and MVO2 during JOHAKU stimulation to ones at baseline.

Results

As shown in Figure 2, JOHAKU attenuated HR immediately after stimulation. Compared with baseline, JOHAKU significantly reduced HR (baseline: 135±13 vs. 5 min on stimulation: 107±13 bpm, p&lt;0.05), and did not affect mean BP significantly (96.2±22.8 vs. 89.4±26.6 mmHg, P=0.59). HR promptly recovered to baseline level after JOHAKU stopped. JOHAKU also reduced MVO2 (0.57±0.43 vs. 0.48±0.38 ml/min, p&lt;0.05).

Conclusion

JOHAKU rapidly attenuated cardiac metabolism burden via the rapid HR reduction. The controllability of HR by JOHAKU without affecting BP enables us to apply the VNS even for patients with hemodynamic instability, such as heart failure and acute myocardial infarction.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical and Research Development

Effect of radiofrequency heating of vacuum-packed nitrite-free sausage on quality properties and microorganism inactivation

The effect of radiofrequency (RF) heating technology at 27 MHz and 8 kW on the quality properties of vacuum-packed nitrite-free sausages was investigated. One of the several advantages of RF heating technology is the use of less time compared to retort heating. RF heating at 125 °C for a holding time of 2 min and retort heating at 121 °C for 7 min reduced Bacillus subtilis to 7 log cfu/g. In addition, the textural properties of the RF-heated sausages were better than those of retort-heated samples. Furthermore, the growth of B. subtilis and general live bacteria at 25 °C were not detected after 42 days of shelf life in the sausages that underwent RF heating at 125 °C with a holding time of 2 min.

Mice with cleavage-resistant N-cadherin exhibit synapse anomaly in the hippocampus and outperformance in spatial learning tasks

N-cadherin is a homophilic cell adhesion molecule that stabilizes excitatory synapses, by connecting pre- and post-synaptic termini. Upon NMDA receptor (NMDAR) activation by glutamate, membrane-proximal domains of N-cadherin are cleaved serially by a-disintegrin-and-metalloprotease 10 (ADAM10) and then presenilin 1(PS1, catalytic subunit of the γ-secretase complex). To assess the physiological significance of the initial N-cadherin cleavage, we engineer the mouse genome to create a knock-in allele with tandem missense mutations in the mouse N-cadherin/Cadherin-2 gene (Cdh2 R714G, I715D, or GD) that confers resistance on proteolysis by ADAM10 (GD mice). GD mice showed a better performance in the radial maze test, with significantly less revisiting errors after intervals of 30 and 300 s than WT, and a tendency for enhanced freezing in fear conditioning. Interestingly, GD mice reveal higher complexity in the tufts of thorny excrescence in the CA3 region of the hippocampus. Fine morphometry with serial section transmission electron microscopy (ssTEM) and three-dimensional (3D) reconstruction reveals significantly higher synaptic density, significantly smaller PSD area, and normal dendritic spine volume in GD mice. This knock-in mouse has provided in vivo evidence that ADAM10-mediated cleavage is a critical step in N-cadherin shedding and degradation and involved in the structure and function of glutamatergic synapses, which affect the memory function.

Spray technology applications of xanthan gum-based edible coatings for fresh-cut lotus root (Nelumbo nucifera)

In this study, the effect of spraying method as an application technique for xanthan gum-based edible coatings was investigated, based on its barrier and microbial properties on fresh-cut lotus root. Xanthan gum solutions (0.1%, 0.3%, and 0.5%) were prepared and incorporated with 2% (w/w) citric acid as an anti-browning agent and 1% (w/w) glycerol as plasticizer. The coatings were then sprayed using a pilot spray system to 5 mm-thick slices of fresh-cut lotus root for 20 s, packed in polyethylene bags, stored for 16 d at 5 °C and analyzed for color, pH, morphology and microbial counts. It was found that spray-coated fresh-cut lotus root samples had significant reduction in the total color changes as compared to non-coated samples. The experimental results suggested that the spray coating treatments were effective in decreasing the enzymatic browning of fresh-cut lotus root during storage which could potentially increase its shelf-life in the market. In addition, we have also found that the xanthan gum-based spray coated treatments were also effective against inhibiting the growth of Bacillus subtilis during 24 h of incubation which were indicated by the lower microbial counts recorded as compared to non-coated fresh-cut lotus root samples. In this part of the work, the author highlighted the spray coating technique of xanthan gum-based edible coatings as a promising strategy in improving the storage stability of fresh-cut lotus root during post-harvest storage. Overall, the application of edible coatings is a promising strategy in extending the shelf life of fresh-cut lotus root. In the future, the author aims to widen the scope of the application of these coatings to other agricultural products which are prone to degradation during storage in the market.

Effective reflection distance and its association with pressure augmentation index under a variety of acute hemodynamic perturbation

 

Effective reflection distance (ERD), a conceptual distance to a major reflection site from the aortic root, is associated with aging and pressure augmentation index (AIx) in clinical population. However, it is poorly understood how ERD varies and associates with AIx within a subject when the hemodynamic condition is changed extensively by acute pharmacological interventions.

Methods

In 13 anesthetized dogs, we measured aortic pressure (AP) and flow (AF) and femoral arterial flow (FF). Using AP, AF and FF, ERD based on an arterial model comprising a tube with frequency-dependent load (ERD_TL) was determined as a physiologically valid reference. ERD was also determined by wave separation (ERD_WSA) and pressure-only analyses (ERD_AW). Hemodynamic condition was changed by administrating zatebradine (bradycardic agent), nitroprusside, noradrenaline, dobutamine, and dextran.

Results

ERD_TL shortened significantly in response to infusion of nitroprusside or dobutamine. ERD_TL was significantly and negatively associated with AIx in multivariate analysis (Figure/Table). Changes in ERD_WSA or ERD_AW, and their association with AIx were not necessarily concordant with those observed in ERD_TL.

Conclusion

For the first time, we demonstrated that under diverse hemodynamic conditions, ERD_TL can change sensitively, and associates with AIx physiologically. This substantiates importance of tight attention to medication at clinical analysis of wave reflection phenomena. ERD_WSA or ERD_AW may not be a surrogate of ERD_TL.

Responses of ERD to drugs

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science (JSPS)

Donepezil markedly prevents the progression of chronic heart failure and renal dysfunction in renal artery stenosis-induced hypertensive rats

Introduction

Parasympathetic activation by donepezil has been shown to improve prognosis in chronic heart failure (CHF) rats following myocardial infarction. We examined whether donepezil is effective in the treatment of another CHF model complicated with renal artery stenosis (RAS)-induced hypertension.

Methods

RAS was created by ligating the left renal artery up to 50% in SD rats, at the same time, we implanted a blood pressure (BP) transmitter for confirming RAS-induced hypertension (7-week post-RAS: systolic BP = 154±7 mmHg; diastolic BP = 115±8 mmHg). In the 11th week after induction of RAS, surviving animals were randomly assigned to untreated (UT, n=10) or donepezil treated [DT, n=10, dissolved in drinking water (3mg/kg/day)] group. After a 6-week treatment, the effects of donepezil were evaluated by hemodynamics, blood levels of neurohumoral markers, and morphology.

Results

Compared with UT, DT significantly prevented the progression of the left kidney atrophy (2.38±0.13 vs. 1.51±0.34 g/kg, P&lt;0.05) and kidney fibrosis (left: −64%, P&lt;0.001; right: −55%, P&lt;0.01). DT also significantly prevented the progression of CHF, through suppressing cardiac hypertrophy (2.30±0.06 vs. 2.57±0.08 g/kg, P&lt;0.01), cardiac fibrosis (−70%, P&lt;0.01), and cardiac dysfunction [cardiac index: 102±3 vs. 86±3 ml/min/kg, P&lt;0.05; left ventricular (LV) end-diastolic pressure: 12±2 vs. 20±2 mmHg, P&lt;0.05; LV dp/dtmin: 5856±259 vs. 4924±227 mmHg/sec, P&lt;0.05]. DT not only decreased serum levels of creatinine (0.54±0.02 vs. 0.63±0.03 mg/dl, P&lt;0.05) and uric acid (1.4±0.2 vs. 1.9±0.2 mg/dl, P&lt;0.05); but also decreased plasma levels of norepinephrine (273±38 vs. 846±242, P&lt;0.01), AVP (2729±347 vs. 4783±695 pg/ml, P&lt;0.05), BNP (360±13 vs. 460±39 pg/ml, P&lt;0.05), angiotensin II and aldosteron, and suppressed the systemic inflammation.

Conclusions

Donepezil treatment markedly prevented the progression of CHF and renal dysfunction, and improved the neurohumoral markers in the CHF rat model complicated with RAS-induced hypertension, suggesting that donepezil may be used as a new pharmacotherapy for CHF patients complicated with RAS-induced hypertension.

Funding Acknowledgement

Type of funding source: None

A minimally-occlusive cuff method utilizing ultrasound vascular imaging for stress-free blood pressure measurement

Objective

Occlusive cuff inflation in ambulatory blood pressure (BP) monitoring disturbs the daily life of the user, and affects efficacy of monitoring. To overcome this limitation, we have developed a novel minimally-occlusive cuff method for stress-free measurement of BP. This study aimed to experimentally evaluate the reliability of this method, and improve the precision of this method by implementing a machine learning algorithm.

Methods

In this method, a thin-plate-type ultrasound probe (Size: 5.6mm-thickness × 28mm × 26mm; weight: 10g) is placed between the cuff and the skin, and used to measure the ultrasonic dimension of the artery (Figure 1). The cuff pressure (Pc), arterial dimension at systole (Ds) and diastole (Dd), systolic BP (SBP) and diastolic BP (DBP) during cuff inflation are theoretically related by the following equations,

SBP-Pc = P0·Exp[α·Ds]

DBP-Pc = P0·Exp[α·Dd]

Where P0 and α are constants, and α indicates arterial stiffness. Since multiple sets of the two equations can be defined over multiple cardiac beats while measuring Pc, Ds and Dd during mild cuff inflation (Pc is controlled less than 50 mmHg, Figure 1), it is possible to estimate SBP (SBPe) and DBP (DBPe) as solutions of the equations. In 6 anesthetized dogs, we attached the cuff and the probe to the right thigh to get SBPe and DBPe, which were one-time calibrated in each animal against reference SBP and DBP measured by using an intra-arterial catheter. We also determined the pulse arrival time (PAT), which is a commonly employed parameter in cuff-less BP monitoring. In all the dogs, BP was changed extensively by infusing noradrenaline or sodium nitroprusside.

Results

DBPe correlated tightly with DBP with a coefficient of determination (R2) of 0.85±0.08, and predicted DBP with error of 3.9±7.9 mmHg after one-time calibration (Figure 2). PAT correlated poorly with DBP (R2=0.49±0.17), and predicted DBP less accurately than this method. SBPe correlated well with SBP (R2=0.78±0.08) (Figure 3). However, even after one-time calibration, difference between SBPe and SBP was 2.6±18.9 mmHg, which was not acceptable. To improve the precision in SBP prediction, we used supervised machine learning approach with use of a support vector algorithm (Python, Scikit-learn), which regressed feature variables (SBPe, DBPe, Ds, Dd heart rate, and PAT) against teacher signal (reference SBP). The support vector algorithm, once trained, predicted SBP with acceptable accuracy with error of 0.7±6.9 mmHg (Figure 3).

Conclusions

This method reliably tracks BP changes without occlusive cuff inflation. Once calibrated, this method measures DBP accurately. With the aid of machine learning, precision in SBP prediction was greatly improved to an acceptable level. This method with machine learning approach has potential for stress-free BP measurement in ambulatory BP monitoring.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science

Donepezil as a novel therapy for suppressing the progression of cardiovascular remodeling in obesity-induced hypertensive rats with reperfused myocardial infarction

Introduction

Acetylcholinesterase inhibition by donepezil has been shown to improve long-term survival in permanent myocardial infarction (MI)-induced chronic heart failure rats. This study examined whether donepezil is applicable to the treatment of obesity-induced hypertension with reperfused MI (RMI).

Methods

Four-week-old SD rats were fed a high-fat diet (57% kcal as fat) for 15 weeks. We implanted a blood pressure (BP) telemetry into the animals (8-week-old) for monitoring artery pressure. After a 1-week recovery, RMI was created by occluding the left coronary artery (30min) followed by reperfusion. Surviving animals were randomly assigned to untreated (UT, n=16) or donepezil treated (DT, n=16, 3 mg/kg/day) group. After a 10-week treatment, the effects of donepezil were evaluated by hemodynamics, blood biomarkers, immunohistochemistry, and morphology.

Results

The high-fat diet caused obesity and hypertension (9-week-old: systolic BP = 134±4 mmHg; diastolic BP = 92±2 mmHg) in the normal rats. Compared with UT, DT significantly decreased the heart rate (296±5 vs. 318±8 bpm, P&lt;0.05). DT significantly prevented the progression of cardiac remodeling and dysfunction [cardiac index: 91±4 vs. 73±9 ml/min/kg, P&lt;0.01; left ventricular (LV) end-diastolic pressure: 11±1 vs. 20±2 mmHg, P&lt;0.01; LV dp/dt max: 5347±206 vs. 3637±433 mmHg/sec, P&lt;0.01], through increasing capillary density (+120%/field, P&lt;0.001), reducing cardiac fibrosis (−50%, P&lt;0.01) and myocardial infarcted area (17±2 vs. 24±2%, P&lt;0.05), suppressing cardiac hypertrophy (2.35±0.04 vs. 2.70±0.14 g/kg, P&lt;0.01) and coronary artery remodeling (wall thickness: 30±1 vs. 37±2 mm, P&lt;0.01; media-to-lumen ratio: 2.3±0.2 vs. 6.2±1.6, P&lt;0.001). Additionally, DT not only decreased plasma levels of insulin, norepinephrine, BNP, angiotensin II, but also improved the systemic inflammation.

Conclusions

Donepezil treatment significantly suppressed the progression of cardiovascular remodeling and dysfunction following RMI in obesity-induced hypertensive rats, suggesting that donepezil may be used as a potential candidate for post-RMI therapy in obesity-induced hypertensive patients.

Funding Acknowledgement

Type of funding source: None

Oil-in-water emulsions containing tamarind seed gum during in vitro gastrointestinal digestion: rheological properties, stability, and lipid digestibility

BACKGROUND

Polysaccharides may enhance/inhibit lipid digestibility of oil-in-water (O/W) emulsions because of their emulsifying and/or stabilizing ability and can also affect the formation, stability, and viscosity of emulsions. Tamarind seed gum (TSG) was used as the sole emulsifier/stabilizer to stabilize an O/W emulsion prepared using high-speed homogenization. We investigated the effects of various TSG concentrations (50-150 g kg^-1 ) on the lipid digestibility, rheological properties, and stability of O/W emulsions during in vitro gastrointestinal digestion.

RESULTS

A low concentration (50 g kg^-1 ) and a high concentration (150 g kg^-1 ) of TSG reduced lipid digestibility by about 33% and 45%, respectively, compared to the control sample (without TSG). However, the emulsion containing the intermediate TSG concentration at 100 g kg^-1 was the most efficient in the inhibition of lipid digestion, reducing lipid digestibility by about 70% compared to that of the control sample. The stability of emulsion tended to enhance as the concentration of TSG increased. The size of oil droplets before passing through the intestinal phase and the viscosity of the intestinal digested system may be important factors for enhancing/inhibiting lipid digestibility of emulsions. The destabilization of the emulsion during digestion was not clearly detected by rheological analysis because rheological characteristics (e.g. flow behavior index) were mainly driven by TSG.

CONCLUSIONS

The addition of TSG in O/W emulsions inhibited lipid digestibility. TSG at a concentration of 100 g kg^-1 was the most efficient in the inhibition of lipid digestibility, suggesting that TSG is an attractive alternative ingredient for control of lipid digestibility of emulsion foods. © 2020 Society of Chemical Industry.

P105 Chronic vagal nerve stimulation suppress thirst through decreasing vasopressin secretion in the rats with chronic heart failure

Introduction

Chronic right cervical vagal nerve electric stimulation (VS) exerted prognostic benefits in heart failure rats. Exploring the mechanism is significant for clinical application. This study examined the effect of VS on arginine vasopressin (AVP) secretion and drinking behavior in the rats with chronic heart failure.

Methods

After a week recovery of myocardial infarction (MI), surviving rats after were randomly instrumented to VS group and sham stimulation (SS) group. A drop sensor was used to record real-time fluid consumption. Blood samples were collected weekly from the 3rd week during the 6 weeks treatment.

Results

Vagal stimulation did not change the daily fluid consumption (Mean ± SE, 76.2 ± 1.1 vs. 77.8 ± 2.1 ml/kg/day, n = 6, P &lt; 0.05). Thirst, which is defined as per drinking volume (PDV), significantly increased during the early weeks after MI (Fig A), while VS significantly suppressed PDV (Fig B is the data of 6th week) by increasing the drinking intervals. The level of plasma AVP was increased to about 2 fold during 6 weeks observation in the SS group, however, VS suppressed this upregulation (Fig C).

Conclusion

These results suggest that VS may activate vagal afferent components which related to inhibition of AVP secretion and then suppressed the augmentation of thirst. Frequent drinking small volume may benefit for homeostasis in CHF.

Abstract P105 Figure. Drinking behavior and AVP

P3501Oral administration of donepezil markedly prevents the progression of chronic heart failure in renal artery stenosis-induced hypertensive rats

Introduction

Parasympathetic activation by donepezil has been shown to improve prognosis in chronic heart failure (CHF) rats following myocardial infarction. We examined whether donepezil is effective in the treatment of another CHF model complicated with renal artery stenosis (RAS)-induced hypertension.

Methods

RAS was created by ligating the left renal artery up to 50% in SD rats, at the same time, we implanted a blood pressure (BP) transmitter for confirming RAS-induced hypertension (7-week post-RAS: systolic BP = 154±7 mmHg; diastolic BP = 115±8 mmHg). At the 11th week after induction of RAS, surviving animals were randomly assigned to untreated (UT, n=10) or donepezil treated [DT, n=10, dissolved in drinking water (3mg/kg/day)] group. After a 6-week treatment, the effects of donepezil were evaluated by hemodynamics, blood levels of neurohumoral markers, and morphology.

Results

Compared with UT, DT significantly prevented the progression of the left kidney atrophy (2.38±0.13 vs. 1.51±0.34 g/kg, P<0.05). DT also significantly improved cardiac remodeling, through suppressing the progression of cardiac hypertrophy (2.30±0.06 vs. 2.57±0.08 g/kg, P<0.01), cardiac dysfunction [cardiac index: 102±3 vs. 86±3ml/min/kg, P<0.05; left ventricular (LV) end-diastolic pressure: 12±2 vs. 20±2 mmHg, P<0.05; LV dp/dtmin: 5856±259 vs. 4924±227 mmHg/sec, P<0.05]. DT not only decreased serum levels of creatinine (0.54±0.02 vs. 0.63±0.03 mg/dl, P<0.05) and uric acid (1.4±0.2 vs. 1.9±0.2 mg/dl, P<0.05); but also decreased plasma levels of norepinephrine (273±38 vs. 846±242, P<0.01), angiotensin II (17±2 vs. 23±2 pg/ml, P<0.05), AVP (2729±347 vs. 4783±695 pg/ml, P<0.05) and BNP (360±13 vs. 460±39 pg/ml, P<0.05), and suppressed the systemic inflammation (CRP: 190±12 vs. 382±58 mg/ml, P<0.01).

Conclusions

Donepezil treatment markedly prevented the progression of cardiac remodeling and renal dysfunction, and improved the neurohumoral markers in the CHF rat model complicated with RAS-induced hypertension, suggesting that donepezil may be used as a new pharmacotherapy for CHF patients complicated with RAS-induced hypertension.

P4605Landiolol, a beta-blocker, optimizes cardiac energetics and peripheral microhemodynamics better than ivabradine while reducing heart rate at hemodynamic resuscitation of experimental septic shock

Background

Septic shock is associated with sympathetic over-activation characterized by tachycardia, which is associated with poor survival. Though several kinds of drugs are available to reduce heart rate (HR), it is not clear which drug should be used to reduce HR effectively in initial hemodynamic resuscitation in septic shock.

Purpose

The aim of this study was to experimentally investigate comparative effects of landiolol (a β-blocker) and ivabradine (an If-channel inhibitor) on initial hemodynamic resuscitation in a canine model of endotoxin shock.

Methods

We used 19 anesthetized dogs. Seven dogs were allocated to control (CT) group, six dogs to landiolol (BB) group, and six dogs to ivabradine (IVA) group. In all the groups, endotoxin shock was induced by intravenous infusion of Escherichia coli lipopolysaccharide (4 mg/kg) over 1 h. After induction of endotoxin shock, we started hemodynamic resuscitation to restore mean arterial pressure (AP) and cardiac output (CO) by infusing noradrenaline (NA) and Ringer acetate solution (RiA). Dose of NA and RiA were automatically titrated with use of a computer-controlled drug infusion system that we developed previously. Hemodynamic resuscitation was continued for 4 h. During resuscitation, the BB group was given landiolol infusion at a low-dose range (1–10 μg/kg/min, manually titrated), while the IVA group was given ivabradine at 0.25 mg/kg bolus-injected every 2 h.

Results

The drug infusion system automatically restored AP to 70 mmHg and CO to greater than 90% of baseline level in all the groups. The restored AP and CO were not significantly different among the three groups (Figure A, B). There were no significant differences in the computer-controlled infusion rate of NA and cumulated volume of RiA infused among the three groups (Figure C). During the first 2 h of resuscitation, HR was significantly reduced in the BB and IVA groups in comparison to the CT group (Figure D). However, only in the BB group, cardiac oxygen consumption was significantly lower than that in the CT group (Figure E). Blood lactate level decreased significantly after hemodynamic resuscitation only within the BB group (Figure F).

Figure 1

Conclusions

In the initial hemodynamic resuscitation of septic shock, both low-dose landiolol infusion and ivabradine injection may be used to reduce HR. However, to optimize cardiac energetics and peripheral microhemodynamics, low-dose landiolol infusion may be preferable to ivabradine injection.

Acknowledgement/Funding

This work was supported by JSPS KAKENHI Grant Number 15K01307, 18K12126.

Randomized clinical trial of extensive intraoperative peritoneal lavage versus standard treatment for resectable advanced gastric cancer (CCOG 1102 trial)

BACKGROUND

A survival benefit of extensive intraoperative peritoneal lavage (EIPL) has been reported in patients with gastric cancer with positive peritoneal cytology. The hypothesis of this study was that EIPL may reduce peritoneal recurrence in patients with advanced gastric cancer who undergo surgery with curative intent.

METHODS

This was an open-label, multi-institutional, randomized, phase 3 trial to assess the effects of EIPL versus standard treatment after curative gastrectomy for resectable gastric cancer of T3 status or above. The primary endpoint was disease-free survival (DFS); secondary endpoints were overall survival, peritoneal recurrence-free survival and incidence of adverse events.

RESULTS

Between July 2011 and January 2014, 314 patients were enrolled from 15 institutions and 295 patients were analysed (145 and 150 in the EIPL and no-EIPL groups respectively). The 3-year DFS rate was 63·9 (95 per cent c.i. 55·5 to 71·2) per cent in the EIPL group and 59·7 (51·3 to 67·1) per cent in the control group (hazard ratio (HR) 0·81, 95 per cent c.i. 0·57 to 1·16; P = 0·249). The 3-year overall survival rate was 75·0 (67·1 to 81·3) per cent in the EIPL group and 73·7 (65·9 to 80·1) per cent in the control group (HR 0·91, 0·60 to 1·37; P = 0·634). Peritoneal recurrence-free survival was not significantly different between the two groups (HR 0·92, 0·62 to 1·36; P = 0·676). No intraoperative complications related to EIPL were observed.

CONCLUSION

EIPL did not improve survival or peritoneal recurrence in patients who underwent gastrectomy for advanced gastric cancer. Registration number: 000005907 (http://www.umin.ac.jp/ctr/index.htm).

The effect of radio-frequency heating on vacuum-packed saury (Cololabis saira) in water

We characterized vacuum-packed whole saury (Cololabis saira) treated using radio-frequency (RF) heating and compared it with that treated using conventional retort heating. RF heating is electrical heating based on dielectric heating. In this study, the effect of RF heating on softening and collagen in backbone was analyzed. RF heating heated the center of fish faster than water. The backbone was softened to a chewable level, and the heating time was shortened to one-third. The amount of crude protein and collagen in backbone decreased with decreasing elasticity, although that heated using RF (131°C) still contained a higher amount than conventional heating. However, β and γ collagen, and then α1 and α2 collagen chain in backbone disappeared with heating; therefore, collagen was degraded to collagen peptide. Results confirmed that RF heating provided wholly eatable fish containing low-molecular collagen peptide in a short heating time.