Stretchable Device for Simultaneous Measurements of Contractility and Electrophysiology of Neuromuscular Tissue in the Gastrointestinal Tract

Devices interfacing with biological tissues can provide valuable insights into function, disease, and metabolism through electrical and mechanical signals. However, certain neuromuscular tissues, like those in the gastrointestinal tract, undergo significant strains of up to 40%. Conventional inextensible devices cannot capture the dynamic responses in these tissues. This study introduces electrodes made from poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and polydimethylsiloxane (PDMS) that enable simultaneous monitoring of electrical and mechanical responses of gut tissue. The soft PDMS layers conform to tissue surfaces during gastrointestinal movement. Dopants, including Capstone FS-30 and polyethylene glycol, are explored to enhance the conductivity, electrical sensitivity to strain, and stability of the PEDOT:PSS. The devices are fabricated using shadow masks and solution-processing techniques, providing a faster and simpler process than traditional clean-room-based lithography. Tested on ex vivo mouse colon and human stomach, the device recorded voltage changes of up to 300 µV during contraction and distension consistent with muscle activity, while simultaneously recording resistance changes of up to 150% due to mechanical strain. These devices detect and respond to chemical stimulants and blockers, and can induce contractions through electrical stimulation. They hold great potential for studying and treating complex disorders like irritable bowel syndrome and gastroparesis.

Investigation of (d, 3n) reaction cross section using theoretical nuclear codes calculations on some nuclear materials

It is important to examine the effects of the nuclear reaction, which is used as a building material in nuclear reactors. Nuclear reactions occur as a result of the interaction between incident particles with the target nuclei. The charged particle-induced reactions have prime importance in understanding the reaction mechanism which can be applicable to understand the particles resulting from the reaction. It is useful to develop shielding the particle accelerators and fusion reactors. The present study contributes to providing the theoretical prediction of excitation functions for ¹¹²Cd (d, 3n)¹¹¹In, ¹⁴¹Pr (d, 3n)¹⁴⁰Nd, ¹⁶⁷Er (d, 3n)¹⁶⁶Tm, ¹⁹⁷Au (d, 3n)¹⁹⁶Hg and ²⁰⁹Bi (d, 3n)²⁰⁸Po reactions using theoretical model codes such as TALYS-1.95, EMPIRE-3.2.3, and ALICE-2014 within the incident deuteron energy range of threshold energy to 50 MeV. Also, newly developed (d, 3n) cross-section formula (Kavun, 2020) calculations have been performed for these reactions at 20 MeV of deuteron energy. Lastly, all calculated results have been compared with one another and with the previously published experimental data of the EXFOR database.

P-229 Has rampant use of ICSI wiped out Conventional IVF for non male factor infertility, or can Conventional IVF hold its ground

Study question

Can ICSI completely replace and produce higher implantation rates as compared to conventional IVF for non-male factor infertility patients?

Summary answer

ICSI has no advantage over Conventional IVF in improving fertilization and implantation rates in non-male factor infertility. Rampant use of ICSI is not recommended.

What is known already

ICSI is the technique of choice for male factor infertility, no argument there. But in the recent times, the unbridled use of ICSI for non male factor patients worldwide has pushed Conventional IVF out of the picture. The evidence states otherwise, ICSI holds no significant advantage over Conventional IVF in couples with normal semen parameters when it comes to fertilization and implantation rates. The mechanical damage as a result of ICSI to oocytes cannot be ignored. Conventional IVF holds a certain advantage in allowing the oocyte to choose the sperm, mimicking in vivo selection.

Study design, size, duration

Prospective randomized study conducted in 140 patients, undergoing IVF & ICSI with non-male factor infertility. The oocytes recovered for all the patients included in the study underwent split insemination, and were divided into 2 groups:

Group 1: Insemination by Conventional IVF, and

Group 2: Insemination by ICSI.

Fertilization and Implantation rates were recorded.

Participants/materials, setting, methods

140 patients with non-male factor cause of infertility were undergoing IVF/ICSI cycle were included in this study. Post ovum pick-up, the oocytes recovered for each patient were split into 2 separate groups and inseminated using Conventional IVF (413) and ICSI (679). The fertilization check was done at 17±1 hours. The implantation rates were noted 14 days after embryo transfer using the beta HCG values. The results were noted and compared.

Main results and the role of chance

In the Conventional IVF(C-IVF) group, fertilization rates were 69.23% compared to 71.44% in the ICSI group.

The implantation rates were 26.50% in C-IVF group vs 22.10% in ICSI group.

Limitations, reasons for caution

A major limitation is the time constraint which did not allow us to track the live birth rates along with the small sample size, the lack of data showing clinical outcomes of this study can be improved upon in the future and with similar studies.

Wider implications of the findings

While ICSI holds the gold standard as the technique of choice for male factor infertility, it is not superior to C-IVF in patients with normal semen parameters. ICSI for all cannot be justified at this moment. Larger RCTs are required to establish superiority of one technique over the other

Trial registration number

not applicable

Effects of some level density models and γ-ray strength functions on production cross-section calculations of 16,18O and 24,26Mg radioisotopes

Oxygen and magnesium isotopes can be used in nuclear reactor materials as cooling, shielding, coating, electronics etc. They can also occur through nuclear reactions during the reactor operation. The exposure of high energy gamma can change the material and its properties, and hence its objective of selection may not remain satisfied. Thus, it is required to study the cross section of different reactions on nuclear reactor materials to understand their sustainability for the properties, for which they are chosen. In the scope of this study, theoretically, different level density model calculations and γ-ray strength functions have been performed for (γ, p) reaction for 16,18O and 24,26Mg nuclei using TALYS 1.9 and EMPI˙RE 3.2.2 codes. Also, semi empirical (γ, p) formula by Tel et al., have been calculated and compared with all results. The effect of different level density models defined in these codes on gamma strength has been studied. Finally, the consistency of these obtained data with EXFOR data have been investigated.

Measurement of 232Th and 238U neutron capture cross-sections in the energy range 5-17 MeV

The neutron capture cross sections of ²³²Th and ²³⁸U at the average neutron energies of 5.08 ± 0.17, 8.96 ± 0.77, 12.47 ± 0.83, and 16.63 ± 0.95 MeV have been measured by using the activation technique and off-line γ-ray spectroscopy. The ²³²Th and ²³⁸U were irradiated with neutrons produced from the ⁷Li(p, n) reaction using the proton energies of 7, 11, 15 and 18.8 MeV from the 14UD BARC-TIFR Pelletron facility in Mumbai, India. Detailed covariance analysis was also performed to evaluate the uncertainties in the measured cross-sections. The excitation function of the ²³²Th(n, γ) and ²³⁸U(n, γ) reactions were calculated using the theoretical model code TALYS-1.9. The experimental and theoretical results from the present work were compared with the ENDF/B-VII-1 and JENDL-4.0 nuclear data libraries and were found to be in good agreement.

TNF-α-induces airway hyperresponsiveness to cholinergic stimulation in guinea pig airways

BACKGROUND AND PURPOSE

TNF-α is an inflammatory cytokine implicated in the pathogenesis of asthma and it causes airway inflammation, bronchoconstriction and airway hyperresponsiveness to a number of spasmogens following inhalation.

EXPERIMENTAL APPROACH

We compared contractions of guinea pig isolated trachea incubated with saline or TNF-α for 1, 2 or 4 days to electrical field stimulation (EFS), 5-HT or methacholine. In addition, we compared bronchoconstriction in anaesthetized guinea pigs 6 h after intratracheal instillation of saline or TNF-α to vagal nerve stimulation, i.v. 5-HT or methacholine. Differential counts were performed on the bronchoalvelolar lavage fluid (BALF).

KEY RESULTS

Maximum contractions to methacholine, 5-HT and EFS were not different between freshly prepared and saline-incubated tissues. Exposure to TNF-α concentration-dependently potentiated contractions to 5-HT and EFS, but not methacholine. All contractions were atropine-sensitive, but not hexamethonium-sensitive. 5-HT-evoked contractions were inhibited by ketanserin or epithelial denudation. Only EFS-evoked contractions were tetrodotoxin-sensitive. Vagal stimulation, i.v. 5-HT or MCh caused a significant atropine-sensitive, frequency- and dose-dependent bronchoconstriction and decreased blood pressure similarly in both saline and TNF-α pre-treated animals. TNF-α potentiated the bronchoconstriction to vagal stimulation and 5-HT, but not MCh. The BALF from saline-treated animals contained predominantly macrophages, whereas that from TNF-α-treated animals contained neutrophils.

CONCLUSIONS AND IMPLICATIONS

TNF-α caused airway hyperresponsiveness to nerve stimulation in vivo and increased contractility in vitro. However, responsiveness to MCh was unchanged, suggesting a pre-synaptic action of TNF-α on parasympathetic nerves. TNF-α-induced airway hyperresponsiveness to 5-HT suggested an increased 5-HT(2A) receptor-mediated acetylcholine release from epithelial cells.

Evidence for both inverse agonism at the cannabinoid CB1 receptor and the lack of an endogenous cannabinoid tone in the rat and guinea-pig isolated ileum myenteric plexus-longitudinal muscle preparation

BACKGROUND AND PURPOSE

Cannabinoid receptor agonists reduce intestinal propulsion in rodents through the CB(1) receptor. In addition to its antagonistic activity at this receptor, rimonabant (N-(piperidino)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-3-pyrazole-carboxyamide) alone augments intestinal transit. Using rat and guinea-pig ileum MPLM (myenteric plexus-longitudinal muscle) preparations, we investigated whether the latter effect was through inverse agonism or antagonism of endocannabinoid agonist(s).

EXPERIMENTAL APPROACH

Inverse agonism was investigated by comparing the maximal enhancement of electrically evoked contractions of the MPLM by two CB(1) receptor antagonists, AM 251 (N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide) and O-2050 [(6aR,10aR)-3-(1-methanesulphonylamino-4-hexyn-6-yl)-6a,7,10,10a-tetrahydro-6,6,9-trimethyl-6-H-dibenzo[b,d]pyran], with that produced by rimonabant. To reveal ongoing endocannabinoid activity, effects of inhibiting endocannabinoid hydrolysis by fatty acid amide hydrolase (FAAH) using AA-5HT (arachidonyl-5-hydroxytryptamine), PMSF (phenylmethylsulphonyl fluoride) or URB-597 (3'-carbamoyl-biphenyl-3-yl-cyclohexylcarbamate), or putative uptake using VDM-11 [(5Z,8Z,11Z,14Z)-N-(4-hydroxy-2-methylphenyl)-5,8,11,14-eicosatetraenamide] was evaluated.

KEY RESULTS

The presence of CB(1) receptors was revealed by antagonism of exogenous anandamide, arachidonylethanolamide (AEA) and WIN 55,212-2 [(R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)-pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-naphthalenylmethanone mesylate] by rimonabant. The rank order of potentiation of contractions was AM 251 > rimonabant > O-2050. Neither the FAAH inhibitors nor VDM-11 affected electrically evoked contractions. Each FAAH inhibitor increased the potency of AEA but not WIN 55,212-2. VDM-11 did not alter the inhibitory effect of AEA.

CONCLUSIONS AND IMPLICATIONS

The different levels of maximal potentiation of contractions by the CB(1) receptor antagonists suggest inverse agonism. The potentiation of the action of AEA by the FAAH inhibitors showed that FAAH was present. The lack of effect of FAAH inhibitors and VDM-11 alone on electrically evoked contractions, and on the potency of exogenous AEA suggests that pharmacologically active endocannabinoids were not released and the endocannabinoid transporter was absent. Thus, the CB(1) receptor antagonists behave as inverse agonists.

The short-circuit current of the ileum, but not the colon, is altered in the streptozotocin diabetic rat

Ion transport in control and streptozotocin-diabetic rat colon and ileum was studied using the Ussing chamber technique. No differences were observed between control and diabetic colonic mucosal short-circuit current under either basal or carbachol (100 nmol/L – 1 µmol/L)-stimulated or prostaglandin E2 (100 nmol/L – 1 µmol/L)-stimulated conditions. Similarly to colonic tissues, no differences in the short circuit current in either carbachol-stimulated or prostaglandin E2-stimulated tissues were observed between control and diabetic ileal mucosa. The basal diabetic ileal short circuit current (99.58 ± 22.67 μA) was significantly greater than that of control ileal tissues (29.67 ± 4.45 μA). This difference was abolished by the sodium–glucose-cotransporter inhibitor, phloridzin (50 µmol/L) (118.00 ± 28.09 μA vs. 25.60 ± 4.59 μA) and was also prevented by the replacement of glucose with mannitol in the buffer bathing the apical side of the tissue (control: 17.05 ± 5.85 μA vs. 17.90 ± 3.10 μA). Acetazolamide (450 µmol/L; a carbonic anhydrase inhibitor), amiloride, and bumetanide (100 µmol/L each; Na+-channel blockers), piroxicam (50 µmol/L; a COX1 cyclooxygenase inhibitor), and ouabain (1 mmol/L; a K+ transport inhibitor) had no effect on the basal short circuit current of either control or diabetic ileal tissues. This indicated that the alteration in the basal short circuit current of diabetic ileal tissues was due to a change in cellular glucose transport, whereas the evoked changes in short circuit current were unaffected by the diabetic state.