-
Echo Research and Practice Dec 2023A reduction in right ventricular (RV) function during recovery from prolonged endurance exercise has been documented alongside RV dilatation. A relative elevation in...
BACKGROUND
A reduction in right ventricular (RV) function during recovery from prolonged endurance exercise has been documented alongside RV dilatation. A relative elevation in pulmonary artery pressure and therefore RV afterload during exercise has been implicated in this post-exercise dysfunction but has not yet been demonstrated. The current study aimed to assess RV structure and function and pulmonary artery pressure before, during and after a 6-h cycling exercise bout.
METHODS
Eight ultra-endurance athletes were recruited for this study. Participants were assessed prior to exercise supine and seated, during exercise at 2, 4 and 6 h whilst cycling seated at 75% maximum heart rate, and post-exercise in the supine position. Standard 2D, Doppler and speckle tracking echocardiography were used to determine indices of RV size, systolic and diastolic function.
RESULTS
Heart rate and RV functional parameters increased from baseline during exercise, however RV structural parameters and indices of RV systolic and diastolic function were unchanged between in-exercise assessment points. Neither pulmonary artery pressures (26 ± 9 mmHg vs 17 ± 10 mmHg, P > 0.05) nor RV wall stress (7.1 ± 3.0 vs 6.2 ± 2.4, P > 0.05) were significantly elevated during exercise. Despite this, post-exercise measurements revealed RV dilation (increased RVD1 and 3), and reduced RV global strain (- 21.2 ± 3.5 vs - 23.8 ± 2.3, P = 0.0168) and diastolic tissue velocity (13.8 ± 2.5 vs 17.1 ± 3.4, P = 0.019) vs pre-exercise values.
CONCLUSION
A 6 h cycling exercise bout at 75% maximum heart rate did not alter RV structure, systolic or diastolic function assessments during exercise. Pulmonary artery pressures are not elevated beyond normal limits and therefore RV afterload is unchanged throughout exercise. Despite this, there is some evidence of RV dilation and altered function in post-exercise measurements.
PubMed: 38115147
DOI: 10.1186/s44156-023-00035-8 -
Journal of the American Heart... Dec 2023Marijuana leaf vaporizers, which heat plant material and sublimate Δ-9-tetrahydrocannabinol without combustion, are popular alternatives to smoking cannabis that are...
BACKGROUND
Marijuana leaf vaporizers, which heat plant material and sublimate Δ-9-tetrahydrocannabinol without combustion, are popular alternatives to smoking cannabis that are generally perceived to be less harmful. We have shown that smoke from tobacco and marijuana, as well as aerosol from e-cigarettes and heated tobacco products, impair vascular endothelial function in rats measured as arterial flow-mediated dilation (FMD).
METHODS AND RESULTS
We exposed 8 rats per group to aerosol generated by 2 vaporizer systems (Volcano and handheld Yocan) using marijuana with varying Δ-9-tetrahydrocannabinol levels, in a single pulsatile exposure session of 2 s/min over 5 minutes, and measured changes in FMD. To model secondhand exposure, we exposed rats for 1 minute to diluted aerosol approximating release of uninhaled Volcano aerosol into typical residential rooms. Exposure to aerosol from marijuana with and without cannabinoids impaired FMD by ≈50%. FMD was similarly impaired by aerosols from Yocan (237 °C), and from Volcano at both its standard temperature (185 °C) and the minimum sublimation temperature of Δ-9-tetrahydrocannabinol (157 °C), although the low-temperature aerosol condition did not effectively deliver Δ-9-tetrahydrocannabinol to the circulation. Modeled secondhand exposure based on diluted Volcano aerosol also impaired FMD. FMD was not affected in rats exposed to clean air or water vapor passed through the Volcano system.
CONCLUSIONS
Acute direct exposure and modeled secondhand exposure to marijuana leaf vaporizer aerosol, regardless of cannabinoid concentration or aerosol generation temperature, impair endothelial function in rats comparably to marijuana smoke. Our findings indicate that use of leaf vaporizers is unlikely to reduce the vascular risk burden of smoking marijuana.
Topics: Animals; Rats; Aerosols; Cannabinoids; Cannabis; Dilatation, Pathologic; Dronabinol; Electronic Nicotine Delivery Systems; Marijuana Smoking; Nebulizers and Vaporizers; Plant Leaves; Smoke
PubMed: 38014661
DOI: 10.1161/JAHA.123.032969 -
World Journal of Gastrointestinal... Jan 2024Esophageal cancer is the seventh most common type of cancer and the sixth leading cause of cancer -related mortality worldwide. Endoscopic submucosal dissection (ESD) is...
Esophageal cancer is the seventh most common type of cancer and the sixth leading cause of cancer -related mortality worldwide. Endoscopic submucosal dissection (ESD) is widely used for the resection of early esophageal cancer. However, post-ESD esophageal stricture is a common long-term complication, which requires attention. Patients with post-ESD esophageal stricture often experience dysphagia and require multiple dilatations, which greatly affects their quality of life and increases healthcare costs. Therefore, to manage post-ESD esophageal stricture, researchers are actively exploring various strategies, such as pharmaceutical interventions, endoscopic balloon dilation, and esophageal stenting. Although steroids-based therapy has achieved some success, steroids can lead to complications such as osteoporosis and infection. Meanwhile, endoscopic balloon dilatation is effective in the short term, but is prone to recurrence and perforation. Additionally, esophageal stenting can alleviate the stricture, but is associated with discomfort during stenting and the complication of easy displacement also present challenges. Tissue engineering has evolved rapidly in recent years, and hydrogel materials have good biodegradability and biocompatibility. A novel type of polyglycolic acid (PGA) sheets has been found to be effective in preventing esophageal stricture after ESD, with the advantages of a simple operation and low complication rate. PGA membranes act as a biophysical barrier to cover the wound as well as facilitate the delivery of medications to promote wound repair and healing. However, there is still a lack of multicenter, large-sample randomized controlled clinical studies focused on the treatment of post-ESD esophageal strictures with PGA membrane, which will be a promising direction for future advancements in this field.
PubMed: 38313459
DOI: 10.4253/wjge.v16.i1.1 -
MedEdPORTAL : the Journal of Teaching... 2023Despite the need for providers skilled in second-trimester dilation and evacuation (D&E) procedures, there are few second-trimester abortion training opportunities for...
INTRODUCTION
Despite the need for providers skilled in second-trimester dilation and evacuation (D&E) procedures, there are few second-trimester abortion training opportunities for OB/GYN residents and other health care trainees. Barriers to such training include restrictive state laws and institutional policies, lack of trained faculty, and limited procedural volume. Simulation-based D&E training is, therefore, a critical tool for OB/GYN residents and other medical professionals to achieve clinical competency.
METHODS
This simulation for OB/GYN residents centers on a 29-year-old woman at 18 weeks gestation with intrauterine fetal demise, requiring learners to perform a second-trimester D&E and manage an unexpected postprocedural hemorrhage. We designed the simulation to be used with a high-fidelity mannequin. Personnel roles required for the simulation included an anesthesiologist, medical assistant, OR nurse, and two OB/GYN faculty. Learner performance was assessed using a pre- and postsimulation learner evaluation, a critical action checklist, and a focus group with simulation facilitators.
RESULTS
Forty-nine residents participated over an 8-year period. Learners demonstrated improved competency performing a second-trimester D&E and increased confidence managing postprocedural hemorrhage after participating in this simulation. In addition, focus group participants reported that a majority of learners demonstrated confidence and effective communication with team members while performing in a decision-making role.
DISCUSSION
In addition to improving learners' clinical competency and surgical confidence for second-trimester D&E procedures, this simulation serves as a valuable instrument for the standardized assessment of learners' performance, as well as an opportunity for all participants to practice teamwork and communication in a high-acuity setting.
Topics: Female; Pregnancy; Humans; Adult; Dilatation; Pregnancy Trimester, Second; Curriculum; Faculty; Checklist
PubMed: 37588139
DOI: 10.15766/mep_2374-8265.11336 -
ESC Heart Failure Aug 2023We assessed the diagnostic yield of genetic testing and the relationship of left ventricular (LV) reverse remodelling (LVRR) with the presence of DNA pathogenic (P) or...
AIMS
We assessed the diagnostic yield of genetic testing and the relationship of left ventricular (LV) reverse remodelling (LVRR) with the presence of DNA pathogenic (P) or likely pathogenic (LP) variants in patients with dilated cardiomyopathy (DCM).
METHODS AND RESULTS
From 680 outpatients followed at the Heart Failure Outpatient Clinic of our institution, we selected subjects with a diagnosis of DCM as defined by LV ejection fraction (LVEF) ≤40% and LV dilatation not explained by coronary artery disease or other causes. All patients were offered genetic investigation of 42 disease-associated DCM genes with next-generation sequencing. Seventy patients fulfilled the definition of DCM and 66 underwent genetic investigation. We identified 18 P/LP variants in 16 patients, with a diagnostic yield of 24%. The most common variants were truncating TTN variants (n = 7), followed by LMNA (n = 3), cytoskeleton Z-disc (n = 3), ion channel (n = 2), motor sarcomeric (n = 2), and desmosomal (n = 1) genes. After a median follow-up of 53 months (inter-quartile range 20-111), patients without P/LP variants exhibited higher systolic and diastolic blood pressure, lower plasma brain natriuretic peptide levels, and a larger extent of LVRR, as reflected by the increase in LVEF (+14% vs. +1%, P = 0.0008) and decrease in indexed LV end-diastolic diameter (-6.5 vs. -2 mm/m , P = 0.03) compared with patients with P/LP variants.
CONCLUSIONS
Our results confirm the high diagnostic yield of genetic testing in selected DCM patients and suggest that identification of P/LP variants in DCM portends poorer LVRR in response to guideline-directed medical therapy.
Topics: Humans; Cardiomyopathy, Dilated; Ventricular Remodeling; Ventricular Function, Left; Stroke Volume; Genetic Testing
PubMed: 37282787
DOI: 10.1002/ehf2.14395 -
DEN Open Apr 2024Obstructive colitis is an acute condition caused by colorectal strictures and requires a combination of therapeutic strategies, including surgery, endoscopic...
Obstructive colitis is an acute condition caused by colorectal strictures and requires a combination of therapeutic strategies, including surgery, endoscopic interventions, and medications. Here, we describe the case of a 69-year-old man who developed severe obstructive colitis owing to diverticular stenosis of the sigmoid colon. We immediately performed endoscopic decompression to avoid perforation. The mucosa of the dilated colon appeared black, suggesting severe ischemia. We considered surgical total colectomy owing to the extensive colitis. However, considering the invasiveness of the emergent surgery, we adopted a conservative approach as enhanced computed tomography demonstrated colonic dilation with maintained blood flow in the deeper layer of the colonic wall and no signs of colonic necrosis, such as peritoneal irritation sign or elevation of deviation enzymes, were observed. Moreover, the patient preferred a conservative approach, and surgeons in our team agreed with this conservative approach. While relapses of colonic dilation occurred several times, antibiotic treatment and repeated endoscopic decompression successfully suppressed the dilation and systemic inflammation. The colonic mucosa healed gradually, and we performed a colostomy without resecting a large portion of the colorectum. In conclusion, severe obstructive colitis with maintained blood flow can be treated with endoscopic decompression instead of emergent resection for a wide portion of the colorectum. Moreover, endoscopic images of improved colitic mucosa obtained through repeated colorectal procedures are rare and noteworthy.
PubMed: 37205318
DOI: 10.1002/deo2.233 -
Proceedings of the National Academy of... Nov 2023Fast and slow earthquakes are two modes of energy release by the slip in tectonic fault rupture. Although fast and slow slips were observed in the laboratory stick-slip...
Fast and slow earthquakes are two modes of energy release by the slip in tectonic fault rupture. Although fast and slow slips were observed in the laboratory stick-slip experiments, due to the sampling rate limitation, the details of the fault thickness variation were poorly understood. Especially, why a single fault would show different modes of slip remains elusive. Herein, we report on ring shear experiments with an ultrahigh sampling rate (10 MHz) that illuminate the different physical processes between fast and slow slip events. We show that the duration of slips ranged from dozens to hundreds of milliseconds. Fast slip events are characterized by continuous large-amplitude AE (acoustic emission) and somewhat intricate variation of the sample thickness: A short compaction pulse during the rapid release of stress is followed by dilation and vibrations of the sample thickness. As the slip ends, the thickness of the sample first recovers by slow compaction and then dilates again before nucleation of the following slip event. In contrast, during slow slip events, the shear stress reduction is accompanied by intermittent bursts of low-amplitude AE and sample dilation. We observed the detailed thickness variation during slips and found that dilation occurs during both fast and slow slips, which is consistent with natural observations of coseismic dilatation. This study may be used to reveal the mechanism of fault slips during fast and slow earthquakes, which explain the potential effect of fast and slow slips on stress redistribution and structural rearrangement in faults.
PubMed: 37967222
DOI: 10.1073/pnas.2305134120 -
Children (Basel, Switzerland) May 2024Ultrasound serves as a valuable tool for the early detection of fetal bowel dilatation, yet the correlation between fetal bowel dilatation and gastrointestinal...
BACKGROUND
Ultrasound serves as a valuable tool for the early detection of fetal bowel dilatation, yet the correlation between fetal bowel dilatation and gastrointestinal malformations remains to be further investigated. This study aims to explore the relationship by conducting a follow-up and analysis of fetuses with bowel dilation.
METHODS
A retrospective analysis was conducted on 113 fetuses with bowel dilatation at our center from July 2014 to December 2019. The location and degree of bowel dilatation were analyzed. ROC curves were constructed based on the diameter of the bowel and its ratio to fetal gestational age.
RESULTS
In total, 40 of 41 cases (97.6%) with upper gastrointestinal dilatation (double-bubble sign) and 46 of 72 cases (63.9%) with lower gastrointestinal dilatation were diagnosed with gastrointestinal malformations postnatally. The AUC of the dilatation diameter was 0.854 with a cutoff value of 18.05 mm in patients with lower gastrointestinal dilatation. The ratio of the diameter to gestational age (D/GA) showed a higher AUC of 0.906 with a cutoff value of 0.4931.
CONCLUSIONS
The presence of the double-bubble sign in fetuses indicates a close association with duodenal obstruction. The risk of gastrointestinal malformations increases when the bowel diameter exceeds 18.05 mm, particularly when the D/GA surpasses 0.4931.
PubMed: 38929249
DOI: 10.3390/children11060670 -
Circulation Research Jan 2024Elevated plasma ceramides and microvascular dysfunction both independently predict adverse cardiac events. Despite the known detrimental effects of ceramide on the...
BACKGROUND
Elevated plasma ceramides and microvascular dysfunction both independently predict adverse cardiac events. Despite the known detrimental effects of ceramide on the microvasculature, evidence suggests that activation of the shear-sensitive, ceramide-forming enzyme NSmase (neutral sphingomyelinase) elicits formation of vasoprotective nitric oxide (NO). Here, we explore a novel hypothesis that acute ceramide formation through NSmase is necessary for maintaining NO signaling within the human microvascular endothelium. We further define the mechanism through which ceramide exerts beneficial effects and discern key mechanistic differences between arterioles from otherwise healthy adults (non-coronary artery disease [CAD]) and patients diagnosed with CAD.
METHODS
Human arterioles were dissected from discarded surgical adipose tissue (n=166), and vascular reactivity to flow and C2-ceramide was assessed. Shear-induced NO and mitochondrial hydrogen peroxide (HO) production were measured in arterioles using fluorescence microscopy. HO fluorescence was assessed in isolated human umbilical vein endothelial cells.
RESULTS
Inhibition of NSmase in arterioles from otherwise healthy adults induced a switch from NO to NOX-2 (NADPH-oxidase 2)-dependent HO-mediated flow-induced dilation. Endothelial dysfunction was prevented by treatment with sphingosine-1-phosphate (S1P) and partially prevented by C2-ceramide and an agonist of S1P-receptor 1 (S1PR1); the inhibition of the S1P/S1PR1 signaling axis induced endothelial dysfunction via NOX-2. Ceramide increased NO production in arterioles from non-CAD adults, an effect that was diminished with inhibition of S1P/S1PR1/S1P-receptor 3 signaling. In arterioles from patients with CAD, inhibition of NSmase impaired the overall ability to induce mitochondrial HO production and subsequently dilate to flow, an effect not restored with exogenous S1P. Acute ceramide administration to arterioles from patients with CAD promoted HO as opposed to NO production, an effect dependent on S1P-receptor 3 signaling.
CONCLUSION
These data suggest that despite differential downstream signaling between health and disease, NSmase-mediated ceramide formation is necessary for proper functioning of the human microvascular endothelium. Therapeutic strategies that aim to significantly lower ceramide formation may prove detrimental to the microvasculature.
Topics: Adult; Humans; Ceramides; Hydrogen Peroxide; Vascular Diseases; Coronary Artery Disease; Human Umbilical Vein Endothelial Cells; Endothelium
PubMed: 38037825
DOI: 10.1161/CIRCRESAHA.123.323445 -
Journal of Clinical Imaging Science 2023This study aimed to compare the safety and efficacy of balloon and non-balloon (or dilator) gastrostomy devices in radiologically inserted gastrostomy (RIG) for patients...
OBJECTIVES
This study aimed to compare the safety and efficacy of balloon and non-balloon (or dilator) gastrostomy devices in radiologically inserted gastrostomy (RIG) for patients with neurological disease.
MATERIAL AND METHODS
A retrospective analysis of 152 patients was conducted at a tertiary care hospital from July 2017 to September 2020. 104 and 48 patients were included in the balloon and non-balloon groups, respectively. The frequency of complications per specific neurological indication as well as the breakdown of the different complications pertaining to each indication was recorded for analysis. The recovery time, fluoroscopy time, contrast volume, peak radiation, and pain management dosages for each procedure were all reviewed to evaluate for statistical differences between the balloon and non-balloon groups. An adjusted model odds ratio (OR) was conducted to evaluate how each of the variables (type of gastrostomy tube, body mass index [BMI], age, and gender) affected the frequency of complications within our cohort.
RESULTS
This study included 152 patients, with an average age of 65.17 years (interquartile range [IQR] = 12.66) and an average BMI of 26.97 (IQR = 7.19). The majority of patients were male (71.1%). The most common indication for the procedure was stroke (24.3%), followed by post-intubation dysphagia (16.4%) and intracranial hemorrhage (11.8%). Amyotrophic lateral sclerosis (ALS) and altered mental status had a similar prevalence at 9.9%. The overall complication rate was 33.8%, overall mortality rate 3.3%, 30-day mortality rate of 2.6%, and no other major complications according to CIRSE criteria. Notably, patients with neurodegenerative disorders exhibited comparable rates of minor complications: 33.3% in ALS (5/15 patients), 50% in myasthenia gravis (1/2 patients), and 100% in muscular dystrophy (1/1 patient). The study compared two groups: the balloon group (104 patients) and the dilator group (48 patients). The balloon group received significantly lower preoperative sedation in the form of fentanyl (Avg = 4.46 min vs. 6.54 min, = 0.287). The balloon group had shorter fluoroscopy time, lower radiation exposure dose, and shorter operating time compared to the dilator group, though not statistically significant. In the logistic regression model, there was no statistical difference in complication rates between the dilator and balloon groups. BMI, age, and gender did not significantly affect minor complication rates.
CONCLUSION
RIG tube insertions may serve as a valuable, alternative approach in providing enteral support in patients with neurological disease.
PubMed: 37941924
DOI: 10.25259/JCIS_78_2023