Defining reference values of arterioles in healthy individuals for studies with adaptive optics imaging.

Purpose: To investigate age-dependent wall to lumen ratio (WLR) reference values for healthy individuals in adaptive optics imaging (AO). WLR serves as an objective, dimensionless parameter for the evaluation of structural changes in vessels caused by conditions like arterial hypertension, diabetes or vascular stenosis. Methods: 50 right eyes of healthy individuals were examined by adaptive optics imaging. The central big arterioles and smaller arterial branches at least one disc diameter away from the optic disc, approximately above or below the macula were measured by the manufacturer's software. The wall-lumen-ratio (WLR), the wall cross-sectional area (WCSA) and lumen diameter (LD) were assessed. Subsequent data analysis was performed with a focus on variables including age, gender and blood pressure. Results: Normative values for WLR, WCSA and LD in 5 different age groups could be established. However, no significant differences between the age groups were found. Intra-subject comparisons revealed significantly higher WLRs on peripheral branches when compared to central arterioles. WLR showed in this normotensive cohort no relevant correlation with the systolic, diastolic and mean blood pressure. Gender and intraocular pressure had no influence on the vascular parameters. Conclusion: AO is capable of examining vascular alterations in arterioles at an almost microscopic level. Age did not seem to alter WLR, normotensive blood pressure parameters showed also no significant impact. AO-based vessel analysis may provide clinically useful biomarkers for cardiovascular health and should be tested in future studies.

Exploring developmental MeHg impact on extraembryonic and cardiac vessels and its effect on cardiomyocyte contractility.

The toxicity of methylmercury (MeHg) during embryonic development is a relevant issue that remains unclear and deserves investigation. In this sense, there is evidence that links the intake of contaminated food with cardiovascular pathologies in human adults and children. Thus, this study aimed to verify the impact of MeHg on the structure and integrity of extraembryonic and cardiac blood vessels and the contractile function of cardiomyocytes, also evaluating embryonic weight and the cardiosomatic index (CSI). Thus, chicken embryos, used as an experimental model, were exposed to a single dose of 0.1 µg MeHg/50 µl saline at E1.5 and analyzed at E10. After exposure, an increase in the number of extraembryonic blood vessels and the veins of the cardiac tissue was observed. These increases were accompanied by a reduction in the content of VEGF and VCAM proteins related to vessel growth and adhesiveness. Together, these results were related to reduced nitrite (NOx) levels. Furthermore, MeHg reduces the number of sarcomeres and increases the content of cardiac troponin I (cTnI), a protein that regulates contraction. In general, exposure to MeHg affected the integrity of extraembryonic and cardiac vessels and the contractile function of cardiomyocytes, which had a systemic impact evidenced by the reduction in embryonic weight gain and CSI.

Long-term outcomes of IVUS-guided and angiography-guided drug-eluting stent implantation for left main coronary artery disease: a retrospective consort study.

BACKGROUND: In patients with unprotected left main coronary artery disease (ULMCAD), this study compared the long-term prognosis of drug-eluting stent insertion guided by intravascular ultrasonography (IVUS) vs. angiography. PATIENTS AND METHODS: This retrospective consort investigation was performed in December 2021. This analysis included 199 patients who underwent IVUS-guided (IVUS group, n = 81) or angiography-guided (angiography group, n = 118) drug-eluting stent implantation at the Affiliated Hospital of Inner Mongolia Medical University between September 2013 and September 2018. Major adverse cardiac events (MACE) were defined as cardiovascular death, sudden cardiac death, myocardial infarction. RESULTS: The IVUS group had considerably lower proportions of MACE within 1 year postoperatively (P = 0.002) and cardiac mortality within 3 years postoperatively (P = 0.018) compared to the angiography group. However, after adjusting for confounding variables, the hazard ratio for 3-year cardiac mortality was similar between the two groups (P = 0.28). In the IVUS group, there was considerably greater minimum lumen diameter (MLD) (P = 0.046), and reduced frequencies of target vessel restenosis (P < 0.050) and myocardial infarction (MI) (P = 0.024) compared to the angiography group. Cox regression analysis for 3-year cardiac mortality found that MSD was independently associated with low cardiac mortality (HR = 0.1, 95% CI: 0.01-14.92, P = 0.030). CONCLUSION: IVUS-guided drug-eluting stent implantation may lead to better long-term prognosis in patients with ULMCAD, and MSD may be a predictor for lower cardiac mortality.

Predictive factors for size change of aorta in patients with acute blunt traumatic aortic injury.

OBJECTIVE: We aimed to investigate the changes in aorta size, the factors affecting size changes in patients with acute blunt traumatic aortic injury and to evaluate the adequacy of the current 120% thoracic endovascular aortic repair graft oversizing policy. DESIGN AND METHODS: This retrospective review study was conducted using the prospectively collected medical records of 45 patients (mean age: 53.5 years, male: 39 patients) with blunt traumatic aortic injury treated at a level 1 trauma center between 2012 and 2021. Aortic diameter was measured by computed tomography angiographic images at four different levels [ascending aorta (A), isthmus (B), descending thoracic aorta (C), and infrarenal aorta (D)] on arrival and follow-up (median time interval, 13 days). Associated factors including patient characteristics and hemodynamic parameters on arrival and follow-up were collected to determine their influence on changes in the aorta. RESULTS: The mean diameter of all four aortic levels increased on follow-up computed tomography compared to initial computed tomography (A: + 11.77%, B: + 10.19%, C: + 7.71%, D: + 12.04%). Patient age and injury severity score influenced changes in the diameter of the ascending aorta (P < 0.05). Patient age and blunt traumatic aortic injury grade were significantly associated with changes in the infrarenal aortic diameter (P < 0.05). Three cases of type 1 endoleak were observed at follow-up but all were spontaneously resolved without further intervention at next computed tomography follow-up. CONCLUSIONS: In patients with acute blunt traumatic aortic injury, aortic diameter is significantly smaller by about 10% under shock and is not considered a basis for oversizing the currently implemented 120% thoracic endovascular aortic repair graft sizing. However, in young patients under the age of 40, the change is significantly large and subsequent computed tomography follow-up is required.

Measurement of Optic Nerve Sheath Diameter by Bedside Ultrasound in Patients With Traumatic Brain Injury Presenting to Emergency Department: A Review.

The aim of this review article is to outline the effectiveness of using bedside ultrasound to measure the optic nerve sheath diameter (ONSD) in order to identify variations in intracranial pressure (ICP) and subsequently avoid the complication of secondary brain injury in patients with traumatic brain injury (TBI), who are admitted to an emergency department (ED). Reputable publications and numerous studies demonstrate the problem's exponential rampancy and pervasiveness. In a TBI patient, the emergence of secondary brain damage has been recognized as a serious emergency. It is believed that secondary brain damage is caused by an abnormally high ICP. High levels of ICP can be measured using both invasive and non-invasive approaches. ONSD measurement via bedside ultrasound has been identified as a quick, useful technique to be used in the ED to avoid potential morbidity and mortality owing to secondary brain injury.

Characteristics of radioactive aerosols during the pre-decommission phase of the experimental shielding reactor.

The decommissioning of nuclear reactors is a global concern, in part because of the generation of radioactive aerosols that can lead to internal radiation exposure. At present, radioactive aerosols generated during nuclear decommissioning have not been actively studied, and data collected from the actual decommissioning are limited. This paper presents a study of radioactive aerosols generated during the pre-decommission phase of an experimental shielding reactor. Among all the on-site operations, cutting resulted in the highest levels of radioactivity. Plasma arc cutting, in particular, had a maximum gross α and ß radioactivity over 0.10 and 0.14 Bq/m3, respectively. Assumed AMAD (activity median aerodynamic diameter) values are employed to assess the impact of particle size on the internal exposure dose resulting from the inhalation of 137Cs aerosols based on the Human Respiratory Tract Model of International Commission on Radiological Protection. When cutting stainless steel by plasma arc, the internal exposure dose caused by 137Cs aerosols with an AMAD of 0.1 µm is estimated to be nearly four times as that of aerosols with an AMAD of 10 µm. Results show that the internal exposure dose is highly dependent on the AMAD, implying the importance of measuring size-related parameters of radioactive aerosols in the future nuclear decommissioning. This study has revealed some characteristics of radioactive aerosols released in decommissioning operations, which can serve as a valuable reference for controlling and removing aerosols during the decommissioning of nuclear facilities.

Genetic Dissection of Major Rice QTLs for Strong Culms and Fine Mapping of qWS5 for Breeding Application in Transplanted System.

BACKGROUND: Rice is one of the major staples that feeds about one half of the global populations, and it is important to identify the genetic loci for the traits related to yield improvement. Lodging will cause severe yield loss when it happens, and stem diameter has been characterized as an important trait for lodging resistance. However, most QTLs for stem diameter have not been finely dissected due to their sensitivity to environmental fluctuation. RESULT: In this study, we performed QTL analysis for stem diameter using populations derived from Nipponbare (NIP) and strong culm variety YYP1, and confirmed the single and combined effect of three major QTLs by recombinant inbred lines (RILs). Based on the QTL location, we found that qWS5 is a novel QTL not well characterized before. To finely dissect the novel locus, several recombinant heterogeneous inbred families (HIFs) were selected from the RILs for linkage analysis and their derived nearly isogenic lines (NILs) were subjected to detailed trait investigation throughout different years. The HIF-NILs strategy confined the QTL to about 380 kb region supported by repeated genotype and phenotype data, and it lays the foundation for QTL cloning in the future. In addition, introgression of the QTL to an elite japonica variety SD785 was performed by successive backcrossing, and it confirmed the value of qWS5 in increasing stem diameter and other agronomic traits during rice breeding. CONCLUSIONS: We prove that qWS5 is a novel QTL with relatively stable effect for stem diameter and the QTL can be finely mapped to small region by the HIF-NILs strategy. The result will facilitate the improvement of rice lodging resistance by molecular marker assisted selection breeding.

Evaluation of the proximal femur using the digital photographs: Does change in proximal femur position due to anteversion affect the measurement of the size of the femoral head diameter?

Background: A plain pelvic radiograph is usually conducted with the lower limbs in internal rotation. This is to correct the anteversion of the femur. However, in the fracture neck of the femur, internal rotation of the fractured limb is avoided, because it would be painful. We examined the effect of correction of anteversion or otherwise on the diameter of the head of the femur using imaging. Objectives: This study aimed to determine if there was a significant difference between the femoral head diameter at two different positions, at the normal anatomical position (without correcting the anteversion) and at the corrected anteversion position. It also aimed to document the correlation and the statistical significance between the differences in the size of the diameter at these two different positions with the anteversion angles of the femoral bone. Materials and Methods: Two sets of digital photographs of the proximal part of 55 non-sexed, non-paired femoral bones were taken. Images obtained were at two positions: normal anatomical (with anteversion uncorrected) and anteversion corrected positions. The diameters of the head of the femur were documented at these two different positions. The anteversion angles and actual femoral head (AFH) diameters were also measured and documented. Results: The femoral head diameters at anatomical positions were persistently larger than those measured after the anteversion was corrected, except in three femoral bones (5%) where no differences were observed. The difference in the two measurements was statistically significant to the anteversion angle of the femoral bone. (P = 0.0005). The means of the two sets of measurements were statistically different from each other. Pairwise correlation showed that both were strongly associated with the AFH diameter but the measurements from images with corrected anteversion had a higher value (0.8166) than the measurements from normal anatomical position (0.7526). Conclusion: The correction of femoral anteversion produced femoral head size measurements that were closer to AFH diameters compared to those without the correction of the femoral anteversion. Femoral anteversion should always be corrected as per protocol.

Border row effects improved the spatial distributions of maize and peanut roots in an intercropping system, associated with improved yield.

Background: Border row effects impact the ecosystem functions of intercropping systems, with high direct interactions between neighboring row crops in light, water, and nutrients. However, previous studies have mostly focused on aboveground, whereas the effects of intercropping on the spatial distribution of the root system are poorly understood. Field experiments and planting box experiments were combined to explore the yield, dry matter accumulation, and spatial distribution of root morphological indexes, such as root length density (RLD), root surface area density (RSAD), specific root length (SRL), and root diameter (RD), of maize and peanut and interspecific interactions at different soil depths in an intercropping system. Results: In the field experiments, the yield of intercropped maize significantly increased by 33.45%; however, the yield of intercropped peanut significantly decreased by 13.40%. The land equivalent ratio (LER) of the maize-peanut intercropping system was greater than 1, and the advantage of intercropping was significant. Maize was highly competitive (A = 0.94, CR=1.54), and the yield advantage is mainly attributed to maize. Intercropped maize had higher RLD, RSAD, and SRL than sole maize, and intercropped peanut had lower RLD, RSAD, and SRL than sole peanut. In the interspecific interaction zone, the increase in RLD, RSAD, SRL, and RD of intercropped maize was greater than that of intercropped peanut, and maize showed greater root morphological plasticity than peanut. A random forest model determined that RSAD significantly impacted yield at 15-60 cm, while SRL had a significant impact at 30-60 cm. Structural equation modeling revealed that root morphology indicators had a greater effect on yield at 30-45 cm, with interactions between indicators being more pronounced at this depth. Conclusion: These results show that border-row effects mediate the plasticity of root morphology, which could enhance resource use and increase productivity. Therefore, selecting optimal intercropping species and developing sustainable intercropping production systems is of great significance.

Consistent decrease in conifer embolism resistance from the stem apex to base resulting from axial trends in tracheid and pit traits.

Introduction: Drought-induced embolism formation in conifers is associated with several tracheid and pit traits, which vary in parallel from stem apex to base. We tested whether this axial anatomical variability is associated with a progressive variation in embolism vulnerability along the stem from apex to base. Methods: We assessed the tracheid hydraulic diameter (Dh), mean pit membrane area (PMA) and the xylem pressure at 50% loss of conductivity (P50) on longitudinal stem segments extracted at different distances from the stem apex (DFA) in a Picea abies and an Abies alba tree. Results: In both trees, Dh and PMA scaled with DFA 0.2. P50 varied for more than 3 MPa from the treetop to the stem base, according to a scaling of -P50 with DFA-0.2 . The largest Dh, PMA and P50 variation occurred for DFA<1.5 m. PMA and Dh scaled more than isometrically (exponent b=1.2). Pit traits vary proportionally with tracheid lumen diameter. Discussion and conclusions: Apex-to-base trends in tracheid and pit traits, along with variations in P50, suggest a strong structure-function relationship that is influenced by DFA. Although the effect of DFA on P50 has not been extensively explored previously, we propose that analyzing the relationship between P50 and DFA could be crucial for a comprehensive assessment of embolism vulnerability at the individual level.

A method for measuring banana pseudo-stem phenotypic parameters based on handheld mobile LiDAR and IMU fusion.

Diameter and height are crucial morphological parameters of banana pseudo-stems, serving as indicators of the plant's growth status. Currently, in densely cultivated banana plantations, there is a lack of applicable research methods for the scalable measurement of phenotypic parameters such as diameter and height of banana pseudo-stems. This paper introduces a handheld mobile LiDAR and Inertial Measurement Unit (IMU)-fused laser scanning system designed for measuring phenotypic parameters of banana pseudo-stems within banana orchards. To address the challenges posed by dense canopy cover in banana orchards, a distance-weighted feature extraction method is proposed. This method, coupled with Lidar-IMU integration, constructs a three-dimensional point cloud map of the banana plantation area. To overcome difficulties in segmenting individual banana plants in complex environments, a combined segmentation approach is proposed, involving Euclidean clustering, Kmeans clustering, and threshold segmentation. A sliding window recognition method is presented to determine the connection points between pseudo-stems and leaves, mitigating issues caused by crown closure and heavy leaf overlap. Experimental results in banana orchards demonstrate that, compared with manual measurements, the mean absolute errors and relative errors for banana pseudo-stem diameter and height are 0.2127 cm (4.06%) and 3.52 cm (1.91%), respectively. These findings indicate that the proposed method is suitable for scalable measurements of banana pseudo-stem diameter and height in complex, obscured environments, providing a rapid and accurate inter-orchard measurement approach for banana plantation managers.

The effect of age on lens parameters and axial length among wide age range of Saudis: A prospective, cross-sectional study.

PURPOSE: The purpose of the study is to establish normative values of eye parameters such as lens thickness (LT), lens diameter (LD), and axial length (AXL) among wide age range of Saudis using Pentacam AXL and compare these values between gender, in addition to that, to find the correlation between the age and those parameters. METHODS: In this prospective cross-sectional study, we measured LT, LD, and AXL in 125 healthy Saudi controls aged between 8 and 60 years using OCULUS Pentacam AXL. The screening tests were performed for each subject to exclude any ocular abnormalities using slit lamp (Haag-Streit BQ 900), refractive error measured using auto refractometer (Topcon KR-1 Autorefractor/Keratometer), and subject who has spherical equivalent more than ± 4.00D and astigmatism more than 1.00DC was excluded from the study. The mean of three readings of LT, LD, and AXL was taken. All examination was applied on one eye (right eye). RESULTS: The overall mean and standard deviation of LT, LD, and AXL was 2.2 mm ± 0.5, 2.7 mm ± 0.6, and 23.8 mm ± 1.0, respectively. There was no statistically significant difference between males and females in these parameters in all age groups, except in Group 2 (age: 19-30 years), there was a statistically significant difference between males and females in AXL, mean difference (M = 0.48), and P = 0.015. The mean of LT and LD was negatively associated with age. However, there was no significant correlation between AXL and age. CONCLUSION: Normative values of LT, LD, and AXL have been established in wide age group of healthy Saudis; the findings of the present study can highlight not only the normal range of the different ocular parameters, namely LT, LD, and AXL, but also their variation with age and gender.

Direct Photobiomodulation Therapy on the Sciatic Nerve Significantly Attenuates Acute Nociceptive Sensitivity Without Affecting Motor Output.

OBJECTIVES: Pharmacologic pain treatments lack specific targeting and often produce unwanted side effects (eg, addiction, additional hyperalgesia). We previously established that the direct application of laser irradiation (direct photobiomodulation [PBM]) of the sural nerve reduces thermal hypersensitivity in a rodent model of chronic pain, but not mechanical hypersensitivity. These observations were consistent with a selective reduction in the small-diameter fiber contribution to electrophysiologically measured evoked response after direct PBM of a sensory nerve (saphenous). However, to our knowledge, direct application of laser irradiation has never been performed in an animal model of acute nociceptive pain or on a mixed nerve in which sensory and motor outcomes can be observed. MATERIALS AND METHODS: In this study, we describe the effects of direct application of laser irradiation (808 nm, 60 mW, 4 minutes) on a mixed nerve (sciatic nerve) in an acute nociceptive pain model (intradermal capsaicin injection) in rats over the course of two weeks. To investigate whether laser irradiation of a mixed nerve alters motor function, in separate experiments, we applied laser irradiation to the sciatic nerve (using the same parameters as in the chronic pain experiments), and force generation of the gastrocnemius was measured. RESULTS: Capsaicin-induced hypersensitivities to mechanical (pin prick) and thermal (Hargreaves) noxious stimuli, associated with Aδ- and C-fibers, showed a maximal reduction of 70% and 56.2%, respectively, by direct PBM, when compared with a control group (vehicle injection, no PBM) on the same day. This reduction was determined to be significant using a mixed-design analysis of variance with a p value < 0.05. Force generation remained unchanged for up to 120 minutes after laser irradiation. In summary, direct PBM selectively inhibits C- and Aδ-fiber transmission while leaving Aɑ-, Aß-, and motor-fiber activity intact. CONCLUSIONS: These results, in conjunction with our previous analyses of laser irradiation effects on the sural nerve in a chronic spared nerve injury pain model, suggest that direct PBM is a promising candidate for treating pain induced by small-diameter fiber activity.

A Comparative Analysis of Follicular Diameter Assessment Versus Doppler Ultrasound in Predicting Ovulation Timing for the Infertility Treatment: Insights From a Prospective Study.

Background Infertility remains a significant challenge affecting millions of couples worldwide, with ovulation abnormalities being a common underlying cause. Pharmacological methods, such as clomiphene citrate, are often used to stimulate ovulation. However, the optimal timing for sexual intercourse during ovulation induction remains contentious. Objectives This study aimed to compare the efficacy of transvaginal ultrasonography (TVS) for measuring follicle size with Doppler ultrasound for assessing changes in blood flow to predict the timing of ovulation. Methods We conducted a comparative analysis involving 64 women undergoing infertility therapy. Participants were evaluated using both TVS to measure follicle diameter and Doppler ultrasound to assess perifollicular blood flow dynamics. The primary outcomes measured included ovulation rates, resistive index (RI) values, peak systolic velocity (PSV) values, and conception rates. Results The analysis showed comparable age distributions between the TVS and Doppler groups. There was no significant correlation between follicle diameter and ovulation when assessed by TVS. However, Doppler ultrasound revealed a substantial association between perifollicular blood flow dynamics and ovulation. Higher ovulation rates were linked to lower RI values and higher PSV values, indicating their potential as predictors of ovulation. Additionally, higher conception rates were positively correlated with increased vascularity in Zone 4 of the endometrium. Conclusion Doppler ultrasonography indices, particularly RI and PSV values, provide critical insights into perifollicular blood flow dynamics and endometrial vascularity, which can enhance the effectiveness of fertility treatments. While these findings highlight the potential of Doppler ultrasound in predicting ovulation and improving treatment outcomes, further research is required to understand the underlying mechanisms and validate these results for personalised treatment strategies.

Fluid Responsiveness and Management in Obstetrics using Point-of-Care Ultrasound.

Fluid management in obstetric care is crucial due to the complex physiological conditions of pregnancy, which complicate clinical manifestations and fluid balance management. This expert review examines the use of point-of-care ultrasound (POCUS) to evaluate and monitor the response to fluid therapy in pregnant patients. Pregnancy induces significant physiological changes, including increased cardiac output and glomerular filtration rate, decreased systemic vascular resistance, and plasma oncotic pressure. Conditions like preeclampsia further complicate fluid management due to decreased intravascular volume and increased capillary permeability. Traditional methods of assessing fluid volume status, such as physical examination and invasive monitoring, are often unreliable or inappropriate. POCUS provides a non-invasive, rapid, and reliable means to assess fluid responsiveness, which is essential in managing fluid therapy in pregnant patients. This review details various POCUS modalities used to measure dynamic changes in fluid status, focusing on the evaluation of the inferior vena cava (IVC), lung ultrasound (Lung US), and the left ventricular outflow tract (LVOT). IVC ultrasound in spontaneously breathing patients determines diameter variability, predicting fluid responsiveness and being feasible even late in pregnancy. Lung ultrasound is critical for detecting early signs of pulmonary edema before clinical symptoms arise and is more accurate than traditional radiography. The LVOT velocity-time integral (VTI) assesses stroke volume response to fluid challenges, providing a quantifiable measure of cardiac function, especially beneficial in critical care settings where rapid and accurate fluid management is essential. The expert review synthesizes current evidence and practice guidelines, suggesting integrating POCUS as a fundamental aspect of fluid management in obstetrics. It calls for ongoing research to enhance techniques and validate their use in broader clinical settings, aiming to improve outcomes for pregnant patients and their babies by preventing complications associated with both under- and over-resuscitation.

Association of maximum uterine diameter with postoperative complications in laparoscopic supracervical hysterectomy: A retrospective cohort study.

OBJECTIVE: To determine the maximum uterine diameter threshold associated with an elevated risk of complications following laparoscopic supracervical hysterectomy (LSH). METHODS: This was a retrospective cohort study from a single tertiary referral center. We enrolled patients who underwent LSH for benign indications at our hospital between January 2013 and June 2023. The primary outcome was the occurrence of surgical complications within the 30-day timeframe of hysterectomy. The covariate included the year of the procedure, patient age, body mass index, parity, American Society of Anesthesiologists classification, comorbidities, history of previous abdominal and pelvic surgery, and preoperative anemia, blood loss, surgical time, hospital stay and pathology. The exclusion criteria comprised those who underwent hysterectomy for malignancy, individuals who underwent total vaginal hysterectomy or laparoscopically assisted vaginal hysterectomy, and those with missing data on uterine maximum diameter, study outcomes, or covariates. RESULTS: We included a final sample of 120 patients, revealing a median uterine diameter of 9.12 cm, with 9.2% experiencing complications. The median uterine weight among 40 patients was 275 g. Receiver operating characteristic (ROC) curve analysis suggested a potential cutoff of 11.55 cm for predicting complications, with an area under the ROC curve of 0.67. Multivariate logistic regression confirmed a significant association between uterine diameter exceeding the cutoff and increased complication risk (OR 33.925, 95% CI: 2.294-501.690, P = 0.0103). A correlation (r = 0.762, P < 0.001) between uterine weight and diameter indicated the latter's suitability for preoperative assessment of uterine weight. CONCLUSION: The maximum uterine diameter with an optimal cutoff of 11.55 cm was associated with increased complication risk.

Does ponticulus posticus affect vertebral artery diameter.

PURPOSE: Ponticulus Posticus, atlantooccipital ligament ossification-induced anomaly, surrounds the vertebral artery and the first cervical nerve root. It is believed to wrap around the first cervical nerve root and the vertebral artery, causing compression. We hypothesized that it would also reduce the diameter of the vertebral artery. METHODS: Between January 1, 2022, and December 31, 2022, cervical spine CT scans taken for any reason were retrospectively reviewed. The images of 1365 patients suitable for evaluation were evaluated by two expert radiologists in 3 dimensions. Among patients with PP, those who underwent cervical angiography were identified for vertebral artery diameter measurement. RESULTS: The average age of the 1365 individuals included in the study (732 males, 633 females) was 55.78 (± 18.85) with an age range of 1-96. Among this group, PP was detected in 288 individuals, resulting in a total prevalence of 21.1%. Right and left vertebral artery diameters were significantly lower in patients with complete PP compared to the absent group (p < 0,001, p < 0,001, respectively). Additionally, it was observed that width and height diameters and artery diameters were positively correlated in patients with Complete PP. CONCLUSIONS: Ponticulus posticus can cause vertebrobasilar insufficiency by reducing the diameter of the vertebral artery. Therefore, imaging and detailed evaluation of this region are important in symptomatic patients.

Predictors of failed left bundle branch pacing implant in heart failure with reduced ejection fraction: importance of left ventricular diameter and QRS morphology.

BACKGROUND: Left bundle branch pacing (LBBP) is considered an alternative to cardiac resynchronization therapy (CRT). However, LBBP is not suitable for all heart failure patients. OBJECTIVE: The aim of our study was to identify predictors of unsuccessful LBBP implantation in CRT candidates. METHODS: A cohort of consecutive patients with indications for CRT were included. Clinical, echocardiography and electrocardiography variables were prospectively recorded. RESULTS: A total of 187 patients were included in the analysis. LBBP implantation was successful in 152/187 (81.2%) patients and failed in 35/187 (18.7%) patients. The causes of unsuccessful implantation were unsatisfactory paced QRS (28/35; 80%), inability to screw the helix (4/35; 11.4%), lead instability (2/35; 5.7%), and high pacing thresholds (1/35; 2.8%). The left ventricular end diastolic diameter (LVEDD), non-LBBB (left bundle branch block) QRS morphology, and QRS width were predictors of failed implantation according to the univariate analysis. According to the multivariable regression analysis, LVEDD [OR 1.31 per 5 mm increase (95% CI 1.05, 1.63) p=0.02] and non-LBBB [OR 3.07 (95% CI 1.08, 8.72) p=0.03] were found to be independent predictors of unsuccessful LBBP implantation. An LVEDD of 60 mm has 60% sensitivity and 71% specificity for predicting LBBP implant failure. CONCLUSIONS: When LBBP was used as CRT, LVEDD and non-LBBB QRS morphology predicted unsuccessful implantation. Non-LBBB triples the likelihood of failed implantation independent of LVEDD. Caution should be taken when considering these parameters to plan the best pacing strategy for patients.

Myelinated peripheral axons are more vulnerable to mechanical trauma in a model of enlarged axonal diameters.

The velocity of axonal impulse propagation is facilitated by myelination and axonal diameters. Both parameters are frequently impaired in peripheral nerve disorders, but it is not known if the diameters of myelinated axons affect the liability to injury or the efficiency of functional recovery. Mice lacking the adaxonal myelin protein chemokine-like factor-like MARVEL-transmembrane domain-containing family member-6 (CMTM6) specifically from Schwann cells (SCs) display appropriate myelination but increased diameters of peripheral axons. Here we subjected Cmtm6-cKo mice as a model of enlarged axonal diameters to a mild sciatic nerve compression injury that causes temporarily reduced axonal diameters but otherwise comparatively moderate pathology of the axon/myelin-unit. Notably, both of these pathological features were worsened in Cmtm6-cKo compared to genotype-control mice early post-injury. The increase of axonal diameters caused by CMTM6-deficiency thus does not override their injury-dependent decrease. Accordingly, we did not detect signs of improved regeneration or functional recovery after nerve compression in Cmtm6-cKo mice; depleting CMTM6 in SCs is thus not a promising strategy toward enhanced recovery after nerve injury. Conversely, the exacerbated axonal damage in Cmtm6-cKo nerves early post-injury coincided with both enhanced immune response including foamy macrophages and SCs and transiently reduced grip strength. Our observations support the concept that larger peripheral axons are particularly susceptible toward mechanical trauma.