Real-World Multicenter Study of PD-1 Blockade in HIV-Associated Classical Hodgkin Lymphoma Across the United States.

BACKGROUND: Despite a higher risk of classical Hodgkin lymphoma (cHL) in people with HIV and the demonstrated safety and efficacy of PD-1 blockade in cHL, there are limited data on the use of these agents in HIV-associated cHL (HIV-cHL). PATIENTS/METHODS: We retrospectively identified patients with HIV-cHL from the "Cancer Therapy using Checkpoint inhibitors in People with HIV-International (CATCH-IT)" database who received nivolumab or pembrolizumab, alone or in combination with other agents, and reviewed records for demographics, disease characteristics, immune-mediated adverse events (imAEs), and treatment outcomes. Changes in CD4+ T-cell counts with treatment were measured via Wilcoxon signed-rank tests. Overall response rate (ORR) was defined as the proportion of patients with partial or complete response (PR/CR) per 2014 Lugano classification. RESULTS: We identified 23 patients with HIV-cHL who received a median of 6 cycles of PD-1 blockade: 1 as 1st-line, 6 as 2nd-line, and 16 as ≥3rd-line therapy. Seventeen (74%) patients received monotherapy, 5 (22%) received nivolumab plus brentuximab vedotin, and 1 received nivolumab plus ifosfamide, carboplatin, and etoposide. The median baseline CD4+ T-cell count was 155 cells/µL, which increased to 310 cells/µL at end-of-treatment (P = .009). Three patients had grade 3 imAEs; none required treatment discontinuation. The ORR was 83% with median duration of response of 19.7 months. The median progression-free survival was 21.2 months and did not differ between patients with <200 versus ≥200 CD4+ cells/µL (P = .95). CONCLUSION: Our findings support the use of PD-1 blockade in HIV-cHL for the same indications as the general population with cHL.

Eucommia ulmoides Leaves Alleviate Cognitive Dysfunction in Dextran Sulfate Sodium (DSS)-Induced Colitis Mice through Regulating JNK/TLR4 Signaling Pathway.

Ulcerative colitis (UC) is one of the inflammatory bowel diseases (IBD) that is characterized by systemic immune system activation. This study was performed to assess the alleviative effect of administering an aqueous extract of Eucommia ulmoides leaves (AEEL) on cognitive dysfunction in mice with dextran sulfate sodium (DSS)-induced colitis. The major bioactive compounds of AEEL were identified as a quinic acid derivative, caffeic acid-O-hexoside, and 3-O-caffeoylquinic acid using UPLC Q-TOF/MSE. AEEL administration alleviated colitis symptoms, which are bodyweight change and colon shortening. Moreover, AEEL administration protected intestinal barrier integrity by increasing the tight junction protein expression levels in colon tissues. Likewise, AEEL improved behavioral dysfunction in the Y-maze, passive avoidance, and Morris water maze tests. Additionally, AEEL improved short-chain fatty acid (SCFA) content in the feces of DSS-induced mice. In addition, AEEL improved damaged cholinergic systems in brain tissue and damaged mitochondrial and antioxidant functions in colon and brain tissues caused by DSS. Also, AEEL protected against DSS-induced cytotoxicity and inflammation in colon and brain tissues by c-Jun N-terminal kinase (JNK) and the toll-like receptor 4 (TLR4) signaling pathway. Therefore, these results suggest that AEEL is a natural material that alleviates DSS-induced cognitive dysfunction with the modulation of gut-brain interaction.

An Importance-Performance Analysis of Korean Middle School Students' Health Management Awareness during the Post-COVID-19 Era Depending on Sex.

This study aimed to conduct importance-performance analyses (IPAs) based on Korean middle school students' health management awareness during the post-coronavirus disease 2019 (COVID-19) era. Data were collected from 867 Korean middle school students (13-15 years old) via online and offline surveys between May and June 2023. Frequency analysis, reliability analysis, IPA based on the entire student group, and IPA depending on sex were carried out with the collected data, which revealed the following. First, regardless of sex, the IPA results indicated that four factors of mental health were located in the third quadrant, with one factor of the same variable in the fourth quadrant. The three factors of disease management were located in the third quadrant. Regarding physical activity, two factors were located in the first quadrant, one in the second quadrant, and one in the third quadrant. Regarding sleep management, two factors were located in the second quadrant, one in the third quadrant, and one in the first quadrant. Regarding eating management, two factors were located in the third quadrant and one in the fourth quadrant. Regarding the social distancing variable, all four factors were located in the third quadrant. Regarding hygiene management, two factors were located in the first quadrant, one in the third quadrant, and one in the fourth quadrant. Furthermore, the IPA results indicated sex differences in regular sports and vigorous movement activities associated with physical activity. Additionally, a sex difference was observed in regular diet associated with eating management. This study proposed possible measures for encouraging middle school students to recognize the importance of health and increase their health-related performance during the COVID-19 endemic phase.

Blunted cardiovascular responses to exercise by inhibiting afferent feedback via spinal cord stimulation in heart failure.

This case study investigated the impact of SCS on alterations in blood pressure during constant-load exercise in a female patient with heart failure. Three different SCS frequencies [No SCS (~0 Hz), Low SCS (~100 Hz), and High SCS (~1000 Hz)] with and without ischaemic stimulation of the legs (cuffs) were randomly applied during constant-load exercise. To determine cardiovascular and ventilatory responses to exercise following SCS frequencies, BP, heart rate (HR), and respiratory gas exchange were measured. This experiment was duplicated in visit 1 and visit 2 with a random application of SCS frequency order and the data were averaged. There were no significant differences among three frequencies with no leg ischaemia. However, High SCS demonstrated lower BP, HR, and respiratory gas exchange relative to No SCS and Low SCS. SCS may be effective in improving cardiovascular and ventilatory responses in HF and high-frequency stimulation provides more clinical benefit; however, further studies are needed.

Efficacy of Digital Therapeutics for Pulmonary Rehabilitation: A Multi-Center, Randomized Controlled Trial.

BACKGROUND: This study aimed to investigate the efficacy and safety of digital therapeutics (DTx), EASYBREATH, for pulmonary rehabilitation (PR) in patients with chronic respiratory diseases (CRDs). MATERIALS AND METHODS: This prospective randomized controlled trial was conducted at multiple centers. Participants were randomly allocated 1:1 to the DTx group (DTxG), provided with DTx using EASYBREATH. The DTxG underwent an 8-week PR program with evaluations conducted at baseline, four weeks, and eight weeks. The control group (CG) underwent one PR session and was advised to exercise and undergo the same evaluation. The primary outcome was the change in six-minute walking distance (6MWD) over eight weeks, and secondary outcomes included changes in scores of Modified Medical Research Council (mMRC), chronic obstructive pulmonary disease assessment test (CAT), and St. George's respiratory questionnaire (SGRQ). RESULTS: The change in 6MWD after eight weeks demonstrated a significant difference between the DTxG and CG (57.68 m vs. 21.71 m, p = 0.0008). The change in mMRC scores (p = 0.0008), CAT scores (p < 0.0001), and total SGRQ scores (p = 0.0003) also showed a significant difference between the groups after eight weeks. CONCLUSIONS: EASYBREATH significantly improved exercise capacity, alleviated dyspnea, and enhanced the overall quality of life at eight weeks. EASYBREATH is a highly accessible, time-efficient, and effective treatment option for CRD with high compliance.

The Impact of Polymers on Enzalutamide Solid Self-Nanoemulsifying Drug Delivery System and Improved Bioavailability.

Enzalutamide (ENZ), marketed under the brand name Xtandi® as a soft capsule, is an androgen receptor signaling inhibitor drug actively used in clinical settings for treating prostate cancer. However, ENZ's low solubility and bioavailability significantly hinder the achievement of optimal therapeutic outcomes. In previous studies, a liquid self-nanoemulsifying drug delivery system (L-SNEDDS) containing ENZ was developed among various solubilization technologies. However, powder formulations that included colloidal silica rapidly formed crystal nuclei in aqueous solutions, leading to a significant decrease in dissolution. Consequently, this study evaluated the efficacy of adding a polymer as a recrystallization inhibitor to a solid SNEDDS (S-SNEDDS) to maintain the drug in a stable, amorphous state in aqueous environments. Polymers were selected based on solubility tests, and the S-SNEDDS formulation was successfully produced via spray drying. The optimized S-SNEDDS formulation demonstrated through X-ray diffraction and differential scanning calorimetry data that it significantly reduced drug crystallinity and enhanced its dissolution rate in simulated gastric and intestinal fluid conditions. In an in vivo study, the bioavailability of orally administered formulations was increased compared to the free drug. Our results highlight the effectiveness of solid-SNEDDS formulations in enhancing the bioavailability of ENZ and outline the potential translational directions for oral drug development.

Potential of Lycii Radicis Cortex as an Ameliorative Agent for Skeletal Muscle Atrophy.

Lycii Radicis Cortex (LRC) is a traditional medicine in East Asia with various beneficial effects, including antioxidant, anti-inflammatory, anti-tumor, anti-diabetic, and anti-depressant properties. However, its potential effects on skeletal muscle atrophy have not been studied. In this study, the protective effects of LRC extract (LRCE) on dexamethasone (DEX)-induced muscle atrophy were investigated in C2C12 myotubes and mice. We evaluated the effect of LRCE on improving muscle atrophy using a variety of methods, including immunofluorescence staining, quantitative polymerase chain reaction (qPCR), Western blot, measurements of oxidative stress, apoptosis, ATP levels, and muscle tissue analysis. The results showed that LRCE improved myotube diameter, fusion index, superoxide dismutase (SOD) activity, mitochondrial content, ATP levels, expression of myogenin and myosin heavy chain (MHC), and reduced reactive oxygen species (ROS) production in dexamethasone-induced C2C12 myotubes. LRCE also enhanced protein synthesis and reduced protein degradation in the myotubes. In mice treated with DEX, LRCE restored calf thickness, decreased mRNA levels of muscle-specific RING finger protein 1 (MuRF1) and atrogin-1, and increased insulin-like growth factor 1 (IGF-1) mRNA level. Moreover, LRCE also repaired gastrocnemius muscle atrophy caused by DEX. Although human studies are not available, various preclinical studies have identified potential protective effects of LRCE against muscle atrophy, suggesting that it could be utilized in the prevention and treatment of muscle atrophy.

The Ecological Design of Marine Urban Green Space Plant Landscaping Based on the Concept of Sustainability.

With global climate change and accelerating urbanization, marine cities face unique environmental challenges. Ecological landscape creation is a form of design planning guided by the disciplines of landscape ecology and ecological aesthetics in the process of urban planning and construction. It seeks a design that can maintain the virtuous cycle of the ecosystem and at the same time maintain the spatial equilibrium of the dynamic development of urban landscapes, so as to make them have good ecological functions and corridor functions. The aim of this study is to explore the ecological design methods of plant landscaping in marine urban green spaces under the concept of sustainability. We first reviewed the concept of sustainable development and its application to urban green space design, especially the special requirements in the marine urban environment. This research focuses on how to select plant species that are adapted to the marine climate and how to promote biodiversity, enhance ecosystem services, and improve the quality of life of urban residents through eco-design approaches. Through the analysis of a number of domestic and international cases of green spaces in marine cities, we found that effective eco-design is not only about choosing the right plant species but also includes the rational management of water resources, soil protection, and ecosystem restoration, among other aspects. This study also points out that public participation and interdisciplinary cooperation play a crucial role in the ecological design process. Finally, this paper carries out a specific analysis of the landscape model landscape evaluation system for the ecological design of plant landscaping in marine urban green spaces and experimentally verifies that, compared with other styles, the experience of the European-style landscape is good overall. However, the view openness rating of the European style landscape is only about 0.42, and the best plant landscaping is the mixed mode of alkali poncho and salt poncho. This study aims to provide a practical reference and guidance for urban planners, landscape architects, and environmentalists.

Revisiting the impact of clinicopathologic characteristics in PD-L1 profile in a large cohort of non-small cell lung cancer.

Background: Immunotherapies using anti-programmed cell death ligand-1 (PD-L1) agents have recently shown remarkable outcomes in patients with non-small cell lung cancer (NSCLC). However, there was a poor correlation between PD-L1 expression and treatment response. Many researchers have focused on the clinicopathological factors associated with prognosis, but the results are conflicting. In the present study, we investigated the clinicopathological significance of PD-L1 overexpression in NSCLC cells. Methods: In total, 344 NSCLC cases with PD-L1 assays were retrospectively analyzed. PD-L1 expression was evaluated via immunohistochemical staining using antibodies against SP263 and SP142. The correlation between clinicopathological factors and PD-L1 expression was analyzed for various clinicopathological features. Results: PD-L1 expression significantly correlated with several poor clinicopathological factors, including the solid component of adenocarcinoma, lymphatic invasion, and recurrence. Squamous cell carcinoma, older age, and male sex were also associated with PD-L1 expression. However, we could not observe correlation between PD-L1 expression and disease-free survival (DFS). A novel finding was that lower metastasis was associated with high PD-L1 expression of SP142 in tumor-infiltrating immune cells (ICs). Conclusions: PD-L1 expression in NSCLC is associated with adverse clinicopathological features and recurrence; therefore, it could be utilized to predict poor prognosis. Furthermore, the high PD-L1 expression of SP142 in tumor-infiltrating ICs could be a potential marker for low metastasis.

Functional characterization of plant specific Indeterminate Domain (IDD) transcription factors in tomato (Solanum lycopersicum L.).

Plant-specific transcription factors (TFs) are responsible for regulating the genes involved in the development of plant-specific organs and response systems for adaptation to terrestrial environments. This includes the development of efficient water transport systems, efficient reproductive organs, and the ability to withstand the effects of terrestrial factors, such as UV radiation, temperature fluctuations, and soil-related stress factors, and evolutionary advantages over land predators. In rice and Arabidopsis, INDETERMINATE DOMAIN (IDD) TFs are plant-specific TFs with crucial functions, such as development, reproduction, and stress response. However, in tomatoes, IDD TFs remain uncharacterized. Here, we examined the presence, distribution, structure, characteristics, and expression patterns of SlIDDs. Database searches, multiple alignments, and motif alignments suggested that 24 TFs were related to Arabidopsis IDDs. 18 IDDs had two characteristic C2H2 domains and two C2HC domains in their coding regions. Expression analyses suggest that some IDDs exhibit multi-stress responsive properties and can respond to specific stress conditions, while others can respond to multiple stress conditions in shoots and roots, either in a tissue-specific or universal manner. Moreover, co-expression database analyses suggested potential interaction partners within IDD family and other proteins. This study functionally characterized SlIDDs, which can be studied using molecular and bioinformatics methods for crop improvement.

Cost-Utility Analysis of Early Detection with Ultrasonography of Differentiated Thyroid Cancer: A Retrospective Study on a Korean Population.

BACKGRUOUND: There is debate about ultrasonography screening for thyroid cancer and its cost-effectiveness. This study aimed to evaluate the cost-effectiveness of early screening (ES) versus symptomatic detection (SD) for differentiated thyroid cancer (DTC) in Korea. METHODS: A Markov decision analysis model was constructed to compare the cost-effectiveness of ES and SD. The model considered direct medical costs, health outcomes, and different diagnostic and treatment pathways. Input data were derived from literature and Korean population studies. Incremental cost-effectiveness ratio (ICER) was calculated. Willingness-to-pay (WTP) threshold was set at USD 100,000 or 20,000 per quality-adjusted life year (QALY) gained. Sensitivity analyses were conducted to address uncertainties of the model's variables. RESULTS: In a base case scenario with 50 years of follow-up, ES was found to be cost-effective compared to SD, with an ICER of $2,852 per QALY. With WTP set at $100,000, in the case with follow-up less than 10 years, the SD was cost-effective. Sensitivity analysis showed that variables such as lobectomy probability, age, mortality, and utility scores significantly influenced the ICER. Despite variations in costs and other factors, all ICER values remained below the WTP threshold. CONCLUSION: Findings of this study indicate that ES is a cost-effective strategy for DTC screening in the Korean medical system. Early detection and subsequent lobectomy contribute to the cost-effectiveness of ES, while SD at an advanced stage makes ES more cost-effective. Expected follow-up duration should be considered to determine an optimal strategy for DTC screening.

Effects of Enteric-Coated Formulation of Sodium Bicarbonate on Bicarbonate Absorption and Gastrointestinal Discomfort.

Sodium bicarbonate is used as an ergogenic supplement to enhance people's performances in various exercises. This study aimed to evaluate the effects of intestinal delivery of sodium bicarbonate on bicarbonate absorption and associated side effects in an experimental human trial. After preparing and assessing enteric-coated and uncoated sodium bicarbonate tablet formulations, pharmacokinetic analysis and gastrointestinal symptom tests were performed after oral administration in the human body. The dose required to increase blood bicarbonate concentration over 5 mmol∙L-1 for the purpose of improving performance during high-intensity exercise was also determined. Enteric-coated tablet formulation protects sodium bicarbonate under acidic conditions and releases bicarbonate in the intestine. Enteric-coated tablet formulation also reduced the oral dose required to achieve a blood bicarbonate concentration over 5 mmol∙L-1 from 300 mg∙kg-1 of uncoated tablet formulation to 225 mg∙kg-1. Gastrointestinal discomfort was significantly decreased for the group given 225 mg∙kg-1 enteric-coated tablets compared to that given 300 mg∙kg-1 uncoated tablets. These results suggest that enteric-coated tablet formulation could reduce the oral dose required in order to achieve a blood bicarbonate concentration over 5 mmol∙L-1 by 25%, from 300 mg∙kg-1 to 225 mg∙kg-1, along with its ability to reduce gastrointestinal discomfort associated with the dosage.

Immune checkpoint inhibitor monotherapy is sufficient to promote microenvironmental normalization via the type I interferon pathway in PD-L1-expressing head and neck cancer.

Immune checkpoint blockers (ICBs) targeting programmed cell death protein 1 (PD-1) have been proven to be an effective first-line therapy against programmed cell death 1 ligand 1 (PD-L1; also known as CD274 molecule)-expressing head and neck squamous cell carcinoma (HNSCC) in recent KEYNOTE-048 trial. However, associated changes in the tumor microenvironment (TME) and underlying mechanisms remain elusive. Oral tumors in C57/BL6 mice were induced by administering 7,12-dimethylbenzanthracene into the buccal mucosa. Single-cell suspension was isolated from tumor tissue; proliferating cells were injected subcutaneously into the left flank of mice to establish Ajou oral cancer (AOC) cell lines. Subsequently, a syngeneic PD-L1-expressing HNSCC model was developed by injecting AOC cells into the buccal or tongue area. The model recapitulated human HNSCC molecular features and showed reliable in vivo tumorigenicity with significant PD-L1 expression. ICB monotherapy induced global changes in the TME, including vascular normalization. Furthermore, the antitumor effect of ICB monotherapy was superior to those of other therapeutic agents, including cisplatin and inhibitors of vascular endothelial growth factor receptor 2 (VEGFR2). The ICB-induced antitumorigenicity and TME normalization were alleviated by blocking the type I interferon pathway. In summary, ICB monotherapy is sufficient to induce TME normalization in the syngeneic model; the type I interferon pathway is indispensable in realizing the effects of ICBs. Furthermore, these results explain the underlying mechanism of the efficacy of ICB monotherapy against PD-L1-expressing HNSCC in the KEYNOTE-048 trial.

Comparison of surgical outcomes for hip fracture between older patients with and without cancer: a propensity score matching analysis.

Research on the treatment outcomes and mortality of patients with cancer and hip fractures remains limited. We aimed to assess the treatment outcomes and mortality in older patients with cancer and hip fractures. We retrospectively reviewed the data of 1264 patients aged ≥ 60 years treated for hip fractures between January 2005 and April 2022. The operation time, blood transfusion-related indicators, postoperative complications, reoperation rate, length of hospital stay, admission to the intensive care unit, mortality rate, and clinical scores were compared. We also performed survival analysis. Subsequently, 1:1 propensity-score matching was performed. In the unmatched cohort, we compared 273 patients with cancer and 991 controls. The cancer group exhibited a higher incidence of pneumonia (P = 0.025) and higher in-hospital and 1-year follow-up mortality rates (P = 0.044 and P < 0.001, respectively). In the matched cohort, the 1-year mortality rate remained higher in the cancer group (P < 0.001). The control group showed a higher survival rate in both unmatched and matched cohorts (P < 0.001 for both). The surgical outcomes for hip fractures were comparable between patients with and without cancer. We recommend surgical treatment for hip fractures in patients with cancer.

Do Patients with Benign Paroxysmal Positional Vertigo Have a Higher Prevalence of Osteoporosis? A Systematic Review and Meta-Analysis.

Benign paroxysmal positional vertigo (BPPV) is a common vestibular disorder characterized by episodic vertigo. BPPV primarily affects older adults. Thus, understanding the potential relationship between BPPV and osteoporosis is clinically important. We performed a systematic search of MEDLINE (PubMed), Embase, and Cochrane Library databases for studies on the risk of osteoporosis between BPPV (+) and BPPV (-) groups up until 17 April 2023. We compared osteoporosis prevalence between groups and performed subgroup analyses for male, female, and older patients (aged ≥ 55 years). The 12 studies included 32,460 patients with BPPV and 476,304 controls. Pooled analysis showed that the BPPV (+) group had a significantly higher osteoporosis risk than the control group (odds ratio [OR], 1.73; 95% confidence interval [CI], 1.45-2.06; p < 0.01). Subgroup analyses also presented similar trends as male (OR, 2.41; 95% CI, 1.18-4.90; p = 0.02), female (OR, 2.14; 95% CI, 1.57-2.92; p < 0.001), and older patient subgroups (OR, 1.91; 95% CI, 1.47-2.49; p < 0.01) showed a higher osteoporosis risk in the BPPV (+) group than in the control group. This meta-analysis supports the hypothesis that patients with BPPV have a higher osteoporosis prevalence than those without.

Higher mortality and longer length of stay in hospitalized patients with newly diagnosed diabetes.

AIMS: We investigated the association between diabetes status at admission and in-hospital outcomes in all hospitalized patients, regardless of the reason for admission. METHODS: All individuals aged 20 years or older who were admitted to Yongin Severance Hospital between March 2020 and February 2022 were included in study. Subjects were categorized into three groups: non-DM, known DM, and newly diagnosed DM, based on medical history, anti-diabetic medications use, and laboratory test. Hospitalization-related outcomes, including in-hospital mortality and length of hospital stay, were compared between groups. RESULTS: 33,166 participants were enrolled. At hospitalization, 6,572 (19.8 %) subjects were classified as known DM, and another 2,634 (7.9 %) subjects were classified as newly diagnosed DM. In-hospital mortality was highest in newly diagnosed DM (HR 1.89, 95% CI 1.58-2.26, p < 0.001) followed by known DM (HR 1.41, 95% CI 1.18-1.69, p < 0.001) compared to non-DM. Length of hospital stay was significantly longer in newly diagnosed DM (median [IQR] 9.0 [5.0-18.0],days) than known DM (median [IQR] 5.0 [3.0-10.0],days)(p < 0.001) and non-DM (median [IQR] 4.0 [2.0-7.0],days). After adjusting for multiple covariates, newly diagnosed diabetes was independently associated with increased in-hospital mortality (p < 0.001). CONCLUSIONS: Diabetes status at admission was closely linked to hospitalization-related outcomes. Notably, individuals with newly diagnosed diabetes demonstrated a higher risk of in-hospital mortality and a prolonged length of hospital stay.

The Importance of Biomarker Testing in the Treatment of Advanced Non-Small Cell Lung Cancer: A Podcast.

The identification of actionable biomarkers and development of targeted therapies have revolutionized the field of lung cancer treatment. In patients with advanced non-small cell lung cancer (NSCLC), biomarker testing can inform selection of effective targeted therapies as well as avoid therapies that are less likely to be effective in certain populations. A growing number of actionable targets, including those involving EGFR, ALK, ROS1, BRAF, MET, KRAS, NTRK, RET, HER2, and PD-L1, can be identified with biomarker testing. More than half of patients with advanced NSCLC have tumors that harbor genetic alterations that can be targeted. When these patients are treated with targeted therapy, survival and quality of life may be significantly improved. In addition, broad-based molecular testing may detect alterations identifying patients who are potentially eligible for current or future clinical trials. Comprehensive biomarker testing rates in communities are often low, and turnaround times for results can be unacceptably long. There is an unmet need for widespread, efficient, and routine testing of all biomarkers recommended by clinical guidelines. New testing techniques and technologies can make this an attainable goal. Panel-based sequencing platforms are becoming more accessible, and molecular biomarker analysis of circulating tumor DNA is becoming more common. In this podcast, we discuss the importance of biomarker testing in advanced NSCLC and explore topics such as testing methodologies, effect of biomarker testing on patient outcomes, emerging technologies, and strategies for improving testing rates in the United States. Supplementary file1 (MP4 121301 KB).

The correlation between carotid artery Doppler and stroke volume during central blood volume loss and resuscitation.

BACKGROUND: Using peripheral arteries to infer central hemodynamics is common among hemodynamic monitors. Doppler ultrasound of the common carotid artery has been used in this manner with conflicting results. We investigated the relationship between changing common carotid artery Doppler measures and stroke volume (SV), hypothesizing that more consecutively-averaged cardiac cycles would improve SV-carotid Doppler correlation. METHODS: Twenty-seven healthy volunteers were recruited and studied in a physiology laboratory. Carotid artery Doppler pulse was measured with a wearable, wireless ultrasound during central hypovolemia and resuscitation induced by a stepped lower body negative pressure protocol. The change in maximum velocity time integral (VTI) and corrected flow time of the carotid artery (ccFT) were compared with changing SV using repeated measures correlation. RESULTS: In total, 73,431 cardiac cycles were compared across 27 subjects. There was a strong linear correlation between changing SV and carotid Doppler measures during simulated hemorrhage (repeated-measures linear correlation [Rrm ]=0.91 for VTI; 0.88 for ccFT). This relationship improved with larger numbers of consecutively-averaged cardiac cycles. For ccFT, beyond four consecutively-averaged cardiac cycles the correlation coefficient remained strong (i.e., Rrm of at least 0.80). For VTI, the correlation coefficient with SV was strong for any number of averaged cardiac cycles. For both ccFT and VTI, Rrm remained stable around 25 consecutively-averaged cardiac cycles. CONCLUSIONS: There was a strong linear correlation between changing SV and carotid Doppler measures during central blood volume loss. The strength of this relationship was dependent upon the number of consecutively-averaged cardiac cycles.

Condition Monitoring of Railway Bridges Using Vehicle Pitch to Detect Scour.

This study proposes the new condition monitoring concept of using features in the measured rotation, or 'pitch' signal, of a crossing vehicle as an indicator of the presence of foundation scour in a bridge. The concept is explored through two-dimensional vehicle-bridge interaction modelling, with a reduction in stiffness under a pier used to represent the effects of scour. A train consisting of three 10-degree-of-freedom carriages cross the model on a profiled train track, each train varying slightly in terms of mass and velocity. An analysis of the pitch of the train carriages can clearly identify when scour is present. The concept is further tested in a scaled laboratory experiment consisting of a tractor-trailer crossing a four-span simply supported bridge on piers. The foundation support is represented by four springs under each pier, which can be replaced with springs of a reduced stiffness to mimic the effect of scour. The laboratory model also consistently shows a divergence in vehicle pitch between healthy and scoured bridge states.