Ultrasound induces contraction of the bladder smooth muscle

L-Type Calcium Channel Modulates Low-Intensity Pulsed Ultrasound-Induced Excitation in Cultured Hippocampal Neurons

As a noninvasive technique, ultrasound stimulation is known to modulate neuronal activity both in vitro and in vivo. The latest explanation of this phenomenon is that the acoustic wave can activate the ion channels and further impact the electrophysiological properties of targeted neurons. However, the underlying mechanism of low-intensity pulsed ultrasound (LIPUS)-induced neuro-modulation effects is still unclear. Here, we characterize the excitatory effects of LIPUS on spontaneous activity and the intracellular Ca2+ homeostasis in cultured hippocampal neurons. By whole-cell patch clamp recording, we found that 15 min of 1-MHz LIPUS boosts the frequency of both spontaneous action potentials and spontaneous excitatory synaptic currents (sEPSCs) and also increases the amplitude of sEPSCs in hippocampal neurons. This phenomenon lasts for > 10 min after LIPUS exposure. Together with Ca2+ imaging, we clarified that LIPUS increases the [Ca2+]cyto level by facilitating L-type Ca2+ channels (LTCCs). In addition, due to the [Ca2+]cyto elevation by LIPUS exposure, the Ca2+-dependent CaMKII-CREB pathway can be activated within 30 min to further regulate the gene transcription and protein expression. Our work suggests that LIPUS regulates neuronal activity in a Ca2+-dependent manner via LTCCs. This may also explain the multi-activation effects of LIPUS beyond neurons. LIPUS stimulation potentiates spontaneous neuronal activity by increasing Ca2+ influx.

Effect of low-intensity focused ultrasound therapy on postpartum uterine involution in puerperal women: A randomized controlled trial

BACKGROUND

Short-term poor uterine involution manifests as uterine contraction weakness. This is one of the important causes of postpartum hemorrhage, posing a serious threat to the mother's life and safety. The study aims to investigate whether low-intensity focused ultrasound (LIFUS) can effectively shorten lochia duration, alleviate postpartum complications, and accelerate uterine involution compared with the sham treatment.

METHODS

A multicenter, concealed, randomized, blinded, and sham-controlled clinical trial was conducted across three medical centers involving 176 subjects, utilizing a parallel group design. Enrollment occurred between October 2019 and September 2020, with a 42-day follow-up period. Participants meeting the inclusion and exclusion criteria based on normal prenatal examinations were randomly divided into the LIFUS group or the sham operation group via computer-generated randomization. Patients in the LIFUS group received usual care with the LIFUS protocol, wherein a LIFUS signal was transmitted to the uterine site through coupling gel, or sham treatment, where no low-intensity ultrasound signal output was emitted. The primary outcome, lochia duration, was assessed via weekly telephonic follow-ups post-discharge. The involution of the uterus, measured by uterine fundus height, served as the secondary outcome.

RESULTS

Among the 256 subjects screened for eligibility, 176 subjects were enrolled and randomly assigned to either the LIFUS group (n = 88) or the Sham group (n = 88). Data on the height of the uterine fundus were obtained from all the patients, with 696 out of 704 measurements (99%) successfully recorded. Overall, a statistically significant difference was noted in time to lochia termination (hazard ratio: 2.65; 95% confidence interval [CI]: 1.82-3.85; P < 0.001). The decline in fundal height exhibited notable discrepancies between the two groups following the second treatment session (mean difference: -1.74; 95% CI: -1.23 to -2.25; P < 0.001) and the third treatment session (mean difference: -3.26; 95% CI: -2.74 to -3.78; P < 0.001) after delivery. None of the subjects had any adverse reactions, such as skin damage or allergies during the treatment.

CONCLUSIONS

This study found that LIFUS treatment can promote uterine involution and abbreviate the duration of postpartum lochia. Ultrasound emerges as a safe and effective intervention, poised to address further clinical inquiries in the domain of postpartum rehabilitation.

Preliminary study of the effect of low-intensity focused ultrasound on postpartum uterine involution and breast pain in puerperal women: a randomised controlled trial

To evaluate the safety and efficacy of low-intensity focused ultrasound (LIFU) therapy in facilitating fundus descent and relieving postpartum breast pain compared with sham treatment. A multicentre, randomised, sham-controlled, blinded trial was conducted. A cohort of 176 eligible participants, who had normal prenatal check-ups and met the inclusion and exclusion criteria, were recruited from three medical centres and subsequently randomized into either the LIFU or sham group. All participants received three treatment sessions, wherein LIFU signal was applied to the uterus and breast sites using coupling gel, with the absence of ultrasound signal output in the sham group. Fundal height measurement and breast pain score were performed after each treatment. The primary outcome, uterine involution, was presented by measuring the fundal height of the uterus. The visual analogue scale (VAS) score, as a secondary outcome, was used to assess breast pain and determine the correlation between breast pain and fundal height as the outcome simultaneously. All participants were randomly assigned to either the LIFU group (n = 88) or sham group (n = 88), with seven individuals not completing the treatment. Overall, a statistically significant difference was noted in the rate and index of fundus descent after each treatment. The rate and index of fundus descent showed greater significance following the second treatment (rate: 1.5 (1.0, 2.0) cm/d; index: 0.15 (0.1, 0.18), P < 0.001) and third treatment (rate: 1.67 (1.33, 2.0) cm/d; index: 0.26 (0.23, 0.3), P < 0.001) in the LIFU group. VAS scores, which were based on the continuous variables for the baseline, first, second, and third treatments in the LIFU group (2.0 (2.0, 3.0), 1.0 (0.0, 2.0), 0.0 (0.0, 1.0), and 0.0 (0.0, 0.0) points, respectively), and the sham group (2.0 (2.0, 2.0), 2.0 (1.0, 2.0), 2.0 (1.0, 3.0), and 3.0 (1.0, 3.0) points, respectively), showed a statistically significant difference between the two groups. Meanwhile, the discrepancies in VAS score classification variables between the two groups were statistically significant. After the third treatment, a notable correlation was observed between the VAS score decrease and fundus descent rate; the more the VAS score decreased, the faster was the fundal decline rate in the LIFU group. LIFU therapy is safe and effective, contributing to the acceleration of uterine involution and the relief of postpartum breast pain.Trial ID The study has registered in the Chinese Clinical Trial Registry (ChiCTR2100049586) at 05/08/2021.

Low-intensity pulsed ultrasound in obstetrics and gynecology: advances in clinical application and research progress

In the past decade, research on ultrasound therapy in obstetrics and gynecology has rapidly developed. Currently, high-intensity ultrasound has been widely used in clinical practice, while low-intensity ultrasound has gradually emerged as a new trend of transitioning from pre-clinical research to clinical applications. Low-intensity pulsed ultrasound (LIPUS), characterized by a non-invasive low-intensity pulse wave stimulation method, employs its non-thermal effects to achieve safe, economical, and convenient therapeutic outcomes. LIPUS converts into biochemical signals within cells through pathways such as cavitation, acoustic flow, and mechanical stimulation, regulating molecular biological mechanisms and exerting various biological effects. The molecular biology mechanisms underlying the application of LIPUS in obstetrics and gynecology mainly include signaling pathways, key gene expression, angiogenesis, inflammation inhibition, and stem cell differentiation. LIPUS plays a positive role in promoting soft tissue regeneration, bone regeneration, nerve regulation, and changes in cell membrane permeability. LIPUS can improve the treatment benefit of premature ovarian failure, pelvic floor dysfunction, nerve damage caused by intrauterine growth restriction, ovariectomized osteoporosis, and incomplete uterine involution through the above biological effects, and it also has application value in the adjuvant treatment of malignant tumors such as ovarian cancer and cervical cancer. This study outlines the biological mechanisms and applications of LIPUS in treating various obstetric and gynecologic diseases, aiming to promote its precise application and provide a theoretical basis for its use in the field.

Low-intensity ultrasound promotes uterine involution after cesarean section: the first multicenter, randomized, controlled clinical trial

OBJECTIVE

To evaluate the clinical efficacy and safety of low-intensity ultrasound (LIUS) in promoting uterine involution and relieving postpartum pain.

METHODS

The randomized controlled clinical trial in this study was conducted at five centers in three regions across China from June 2014 to December 2014. A total of 498 subjects were randomly divided into two groups. The LIUS group received ultrasound treatment, and the control group received sham ultrasound treatment. The fundal height and visual analogue scale (VAS) scores of the subjects following cesarean section were recorded separately before and after five treatments. The incidence of adverse events was recorded, while the records on lochia duration were obtained by telephone follow-up. The Full Analysis Set (FAS) comprised all subjects randomized who received at least one treatment. The Per-Protocol Set (PPS) comprised all patients who did not seriously violate the study protocol and had good compliance with complete report forms. Efficacy analyses were performed based on the FAS and PPS. All safety analyses were performed based on the safety set (SS), which included all patients who received at least one treatment.

RESULTS

In the analysis of PPS and FAS, the LIUS group performed better than the control group in reducing the fundal height, shortening the duration of lochia, and relieving postpartum pain, with a significant difference between the two groups (p < 0.0001). In the SS analysis, there were no treatment-related adverse events observed in either group.

CONCLUSIONS

The LIUS therapy is safe and effective, which contributes to uterine involution and the alleviation of postpartum pain.

Pelvic Organ Prolapse: A Review of In Vitro Testing of Pelvic Support Mechanisms

Background: Pelvic organ prolapse (POP) affects a significant portion of the female population, impacting quality of life and often requiring intervention. The exact cause of prolapse is unknown.

Methods: We review some of the current research that focuses on defining the elements involved in POP, with a focus on in vitro testing.

Results: Treatment for POP, ranging from physical therapy or pessary use to more invasive surgery, has varying success rates. This variation is, in part, because the pathophysiology of pelvic floor support—and thus dysfunction—is incompletely understood, particularly regarding the structural components and biomechanical properties of tissue. However, researchers are working to identify and quantify the structural and functional dysfunction that may lead to the development of this condition.

Conclusion: Given the limited understanding of prolapse development, more research is needed to quantify the microstructure of the pelvic organs and pelvic support structures, with and without prolapse. Identifying biomechanical properties in multiaxial configurations will improve our understanding of pelvic tissue support, as well as our ability to establish predictive models and improve clinical treatment strategies.