An innovative cardiac rehabilitation based on the power-force-velocity profile to further improve cardiorespiratory capacities in coronary artery disease patients

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Doctoral contract 2018-2022

Background

Several studies have shown the importance of the relationship between the power-force-velocity profile (PFVP) and sport performance in elite athletes through optimised exercise training.[1] Optimising the training programme is constantly sought in rehabilitation among patients always younger with coronary artery disease. Nowadays, it is well established that intermittent training should be offered to coronary patients during the rehabilitation cycle.[2] In this continuity, the assessment of the PFVP at the beginning of the cardiac rehabilitation (CR) would allow to better adapt the CR training programme for each patient.

Purpose

The aim of this study was to compare the effects of two exercise training programmes: a traditional CR versus a new CR relied on patient’s PFVP on cardiorespiratory, functional and autonomic systems in coronary patients.

Methods

This prospective randomized controlled trial was conducted from May 2020 to July 2021 in an university hospital. A total of 89 patients were randomly assigned (1:1) to test or control group. Before starting CR, participants performed two sprints of 8 s on a cycle ergometer to define the PFVP. The PFVP was analysed to determine whether the participant had a force or velocity deficit. Patients included in test group followed a specific cycling training programme based on their weak point (i.e., specific force training with high resistance and low pedalling frequency on the cycle if the PFVP was oriented in velocity and reversely). While control patients attended a conventional CR programme.

The 3-week training intervention consisted of 40 min of cycling, 30 min of walking on treadmill and 20 min of strength training (4/week).

Cardiopulmonary exercise test (VO2 at the first ventilatory threshold, SV1 and VO2 peak in ml/min/kg), functional assessments (distance of 6-min walk test, handgrip strength, 10 sit-to-stand repetitions, cholesterol levels, LDL-C and quality of life) and autonomic nervous system (heart rate variability and sensitivity baroreflex) were performed at the baseline and after CR.

A two-way ANOVA with one repeated measure (pre vs. post) and one independent factor (test vs. control) was realized.

Results

The mean age was 61.0 ± 9.6 years, 18% were women. A significant difference was observed in VO2 peak (test: +22.0 ± 19.1% vs. control: +10.2 ± 15.8%, p=0.003) and VO2 SV1 (test: +35.9 ± 33.9% vs. control: +11.9 ± 34.4%, p<0.001), LDL-C (p=0.016) and quality of life (p<0.001). No significant change between groups in other functional tests and autonomic activity occurred after CR programme.

Conclusion

Cardiopulmonary activity, cholesterol and quality of life were improved after 3-week exercise programme. The novel CR depending on initial PFVP showed greater cardiorespiratory benefits than a conventional CR. Therefore, the PFVP can be used in CR to adapt specifically the content of training sessions.

Plasmon-enhanced scattering and charge transfer in few-layer graphene interacting with buried printed 2D-pattern of silver nanoparticles

Hybrid structures combing silver nanoparticles and few-layer graphene have been synthetized by combining low-energy ion beam synthesis and stencil techniques. A single plane of metallic nanoparticles plays the role of an embedded plasmonic enhancer located in dedicated areas at a controlled nanometer distance from deposited graphene layers. Optical imaging, reflectance and Raman scattering mapping are used to measure the enhancement of electronic and vibrational properties of these layers. In particular electronic Raman scattering is shown as notably efficient to analyze the optical transfer of charge carriers between the systems and the presence of intrinsic and extrinsic defects.

Fracture of the cobalt-chromium modular femoral neck component in total hip arthroplasty

Total hip prostheses using cervico-metaphyseal modularity were designed to better replicate the geometry of the native extra-medullary femur. However, they are associated with numerous complications including corrosion, disassembly, pseudotumours and, most notably, fractures of the modular neck. All reported cases of modular neck fractures occurred with titanium components (Ti-6Al-4V). To prevent this weakness, manufacturers developed modular necks made of cobalt-chromium (Co-Cr). We report a fracture of a long, 8° varus, Co-Cr modular neck connected to a 36-mm short (-3.5mm) femoral head. The fracture occurred 22 months post-implantation in a woman who had a low level of physical activity and a body mass index of 28.7 kg/m(2). To our knowledge, this case is the first reported instance of Co-Cr modular neck fracture. It may challenge the wisdom of further developing this modularity design, as our patient had none of the known risk factors for modular neck fracture. In addition, cases of pseudotumour have been reported with Co-Cr modular necks subjected to fretting corrosion, which contributed to the fracture in our patient.

[Recommendations for the standardization of growth hormone assays]

The diagnosis of growth hormone (GH) deficiency is based on the GH biological response to pharmacological stimulation tests. The cut-off value defining normality is the same whatever the GH assay used. In a group of the French Society for Clinical Biology (SFBC), we have evaluated whether differences between the GH concentrations obtained with the 9 commercial GH assays available in France exist or not. The study samples consisted of 72 serum pools and serial dilutions of the recombinant GH 22 kDa international standard, IS 98/574. These dilutions were performed by using 3 different diluents: the specific diluent provided by the manufacturers and thus different from one assay to another, serum without GH and heparin plasma without GH. Despite being calibrated against the same international standard, the different assays proposed variable conversion factors between microg and mIU, and we decided to express the results in mIU. The GH concentrations obtained for the 72 serum pools with the 9 assays were highly correlated, but absolute concentrations were significantly different from one assay to another. In particular, the ratio between the concentrations measured with both assays giving the lowest and highest concentration in the same sample respectively was about 50%. In the recovery test executed by adding the international standard, the slope of the regression curve describing the relationship between expected and measured concentrations was different of 1 in all but one assay. Furthermore, for a given assay and a given expected concentration, the measured values were sometimes different by up to 30% depending on the diluent used. These results led us to advise the manufacturers to calibrate their assays against the recombinant GH international standard, IS 98/574, to take into account the matrix effect detected in our study and to use the official conversion factor of 3 mIU/microg. Waiting for this new calibration, it is recommended that the results should be expressed in mIU/L and that serum samples should be used for the measurement of GH instead of plasma samples.

Vascular endothelial cell growth factor (VEGF), an emerging target for cancer chemotherapy

Angiogenesis is a process of development and of growth of new capillary blood vessels from pre-existing vessels. When pathological, it contributes to the development of numerous types of tumors, and the formation of metastases. In order to grow, carcinoma need new blood vessels to form so that they can feed themselves. Therefore, nowadays the concept according to which the development of cancer is angiogenesis dependent is generally recognized. This concept makes the control of tumoral angiogenesis one of the promising therapeutic ways in cancerology. The transition from the latent phase to the invasive and metastatic phase of a cancer is linked to what is called the angiogenic switch. It implies complex cellular and molecular interactions between cancerous cells, endothelial cells and the components of the extra-cellular matrix and namely the existence of specific proteins secreted by the tumoral cells able to stimulate the proliferation of capillary endothelial cells. Among them, VEGF, Vascular Endothelial Growth Factor was found in several types of tumors. It has shown a tumoral angiogenic activity in vitro and in vivo, and thus is a privileged target for the control of angiogenesis in an anti-tumoral goal. The role of VEGF in tumoral angiogenesis has been extensively studied. It has been proved to undergo as well autocrine as paracrine stimulation of tumoral angiogenesis. During the last few years, several members of the VEGF family have been described namely the VEGF-A, B, C, D, E and placenta growth factor (PlGF) among which VEGF-A (121 aminoacids) plays a role of prime importance in angiogenesis. VEGF is a 45 kDA glycoprotein, homodimeric, basic, and able to bind heparin. The three-dimensional structure of VEGF has been recently determined, by X-rays diffraction, and NMR spectroscopy. The different forms of the VEGF bind to receptors that exhibit a tyrosine-kinase activity (RTK). The specific action of the VEGF on the endothelial cells is mainly regulated by two types of RTK of the VEGF family, VEGFR1, or Flt-1, and VEGFR2, or KDR/Flk-1. Mutagenesis studies have shown that only a small number of VEGF residues are important and essential for the binding with RTK. Data described to date from the studies of VEGF/RTK interactions agree to the hypothesis that KDR receptor is the main human receptor responsible for the VEGF activity in both physiological and pathological vascular development, and VEGF-KDR signalling pathway has been validated as a priority target for the development of anti- and pro- angiogenic agents. Therefore angiogenesis mediated by VEGF constitutes a new target for anti-cancer therapy which has explored through different ways of intervention aiming at the blocking of the tumoral angiogenesis. The main ones are: -Struggle against the stroma degradation and invasion by the neo-vessels -Inhibition of activated endothelial cells. -Inhibition of angiogenic factors production and of their receptors. -Inhibition of the VEGF signal pathway, by peptides blocking the bond between VEGF and its receptors through the inhibition of intracellular transduction of VEGF signal. In conclusion, this bibliographic study allows to situate works of medicinal chemistry in the context of present knowledge concerning the vascular endothelial growth factor (VEGF) and its role in angiogenesis.

Melanin affinity of N-(2-diethylaminoethyl)-4-iodobenzamide, an effective melanoma imaging agent

The cellular uptake and incorporation in macromolecules of iodine-125 labelled N-(2-diethylaminoethyl)-4-iodobenzamide ([125I]BZA), a melanoma imaging agent, was studied using human melanoma cells M3Dau (amelanotic) and M4Beu (melanotic). The interaction between [125I]BZA and synthetic melanin was examined in various conditions of incubation. The results showed that uptake was high only for M4Beu, whereas the incorporation in trichloroacetic acid-precipitable proteins was very low for both model cell lines, with no correlation with melanin content. Experiments with synthetic melanin showed that BZA binding to melanin was saturable and reversible, and involved several types of interaction. The influence of the ionic environment indicated that electrostatic forces play a role in the affinity, and the decrease in binding produced by the presence of an alcohol in the medium suggested that hydrophobic interactions may be involved in the binding mechanism. This was supported by the Scatchard analysis, which revealed two classes of binding sites, and the determination of two association constants (K1 = 3.9 +/- 1.9 x 106/M and K2 = 2.9 +/- 0.9 x 104/M). The affinity of BZA for melanin might explain the good results obtained in a phase II clinical trial for the diagnosis of malignant melanoma metastases, in which the specificity was 100%.

Synthesis, characterization and comparative biodistribution study of a new series of p-iodine-125 benzamides as potential melanoma imaging agents

Iodobenzamides are reported to possess some affinity for melanoma. In order to identify the compound having the most appropriate pharmacokinetic properties as a potential melanoma imaging agent, thirteen new [125I]radioiodobenzamides with a butylene amide-amine spacer and various substituents on the terminal amino group were investigated. Their synthesis, radioiodination and biodistribution in B16 melanoma bearing C57BL6 mice are described and compared to [125I] labeled N-(2-diethylaminoethyl)-4-iodobenzamide ([125I]BZA), our reference compound. Changes in the terminal amino constituents induced modifications of lipophilicity, tumor uptake and organ distribution. The dimethylaminobutyl iodobenzamide appeared to be the most promising radiopharmaceutical imaging agent for the detection of melanoma and its metastases.

Synthesis and evaluation of the in vivo trypanocidal activity of water soluble organotin compounds

A series of (3-(2-methoxy)ethoxypropyl)tin derivatives were synthesized as potential trypanocidal drugs. The series included an alkyltin trichloride, a dialkyltin dichloride and the corresponding dialkyltin oxide, and six dialkyltin dithio derivatives. Compounds were evaluated for trypanocidal activity using in vitro cultures of Trypanosoma equiperdum and mice infected with the same strain of parasite for in vivo tests. Two of the title derivatives, the bis (3-(2-methoxy)ethoxypropyl)tin dichloride 2 and the corresponding bis (3-(2-methoxy)ethoxypropyl)tin oxide 3, appeared to be water soluble reagents. Furthermore, they are the first examples of organotin compounds presenting interesting in vivo trypanocidal activity.

Synthesis, radiolabeling, and preliminary evaluation in mice of some (N-diethylaminoethyl)-4-iodobenzamide derivatives as melanoma imaging agents

N-(2-Diethylaminoethyl)-4-iodobenzamide (BZA) is a radiopharmaceutical recently developed in our laboratory for the scintigraphic detection of melanoma and metastases. Optimal time for imaging was between 18-24 h p.i. of [123I] BZA. With a view to selecting compounds able to provide quality images shortly after the injection, synthesis of an initial series of BZA derivatives and their evaluation in B16 melanoma bearing mice have been carried out. The [125I] radiolabeled products were obtained by a simple isotopic exchange procedure with high radiochemical yields (85-95%). After i.v. administration of the compounds we observed a good tumoral targeting ability. Tumoral activity peaked at 2.6 to 7.70% injected dose per g within 1 h post-injection. One of the benzamides with a blood clearance faster than that of BZA--0.06 vs. 0.2% I D/g--6 h p.i. gave the same tumor to blood and to organ ratios as BZA at 12-18 h p.i. Based on these preclinical data we hope to obtain good tumoral images 6 h p.i. in scintigraphic studies in man.

Simultaneous noninvasive evaluation of gastric emptying and orocaecal transit times. Use in studying the actions of cisapride in diabetic patients

The aim of the study was to use a novel combination of two methods for the simultaneous evaluation of two effects of oral cisapride in 10 diabetic patients with autonomic neuropathy; gastric empyting time was measured by following radio-opaque markers and orocaecal transit time by the sulphasalazine-sulphapridine method. The study was of double-blind, randomized, placebo-controlled, cross-over design. It was possible to evaluate the effect of a prokinetic drug on gastric emptying and orocaecal transit times using these two noninvasive techniques at the same time. Cisapride significantly reduced both the gastric empyting (1.2 h versus 2.1 h) and orocaecal tansit (5.9 h versus 7.7 h) times.