Live Cell Imaging Reveals the Dynamics of Telomerase Recruitment to Telomeres.

Telomerase maintains genome integrity by adding repetitive DNA sequences to the chromosome ends in actively dividing cells, including 90% of all cancer cells. Recruitment of human telomerase to telomeres occurs during S-phase of the cell cycle, but the molecular mechanism of the process is only partially understood. Here, we use CRISPR genome editing and single-molecule imaging to track telomerase trafficking in nuclei of living human cells. We demonstrate that telomerase uses three-dimensional diffusion to search for telomeres, probing each telomere thousands of times each S-phase but only rarely forming a stable association. Both the transient and stable association events depend on the direct interaction of the telomerase protein TERT with the telomeric protein TPP1. Our results reveal that telomerase recruitment to telomeres is driven by dynamic interactions between the rapidly diffusing telomerase and the chromosome end.

Novel quantitative immunohistochemistry method using histone H3, family 3B as the internal reference standard for measuring human epidermal growth factor receptor 2 expression in breast cancer.

BACKGROUND: Immunohistochemistry (IHC) is an essential technique in surgical and clinical pathology for detecting diagnostic, prognostic, and predictive biomarkers for personalized cancer therapy. However, the lack of standardization and reference controls results in poor reproducibility, and a reliable tool for IHC quantification is urgently required. The objective of this study was to describe a novel approach in which H3F3B (histone H3, family 3B) can be used as an internal reference standard to quantify protein expression levels using IHC. METHODS: The authors enrolled 89 patients who had human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC). They used a novel IHC-based assay to measure protein expression using H3F3B as the internal reference standard. H3F3B was uniformly expressed at the protein level in all tumor regions in cancer tissues. HER2 expression levels were measured with the H-score using HALO software. RESULTS: Kaplan-Meier analysis indicated that, among patients who had HER2-positive BC in The Cancer Genome Atlas data set and the authors' data set, the subgroup with low HER2 expression had a significantly better prognosis than the subgroup with high HER2 expression. Furthermore, the authors observed that HER2 expression levels were precisely evaluated using the proposed method, which can classify patients who are at higher risk of HER2-positive BC to receive trastuzumab-based adjuvant therapy. Dual-color IHC with H3F3B is an excellent tool for internal and external quality control of HER2 expression assays. CONCLUSIONS: The proposed IHC-based quantification method accurately assesses HER2 expression levels and provides insights for predicting clinical prognosis in patients with HER2-positive BC who receive trastuzumab-based adjuvant therapy.

Abnormal metabolism in melanocytes participates in the activation of dendritic cell in halo nevus.

A comprehensive analysis of spatial transcriptomics was carried out to better understand the progress of halo nevus. We found that halo nevus was characterized by overactive immune responses, triggered by chemokines and dendritic cells (DCs), T cells, and macrophages. Consequently, we observed abnormal cell death, such as apoptosis and disulfidptosis in halo nevus, some were closely related to immunity. Interestingly, we identified aberrant metabolites such as uridine diphosphate glucose (UDP-G) within the halo nevus. UDP-G, accompanied by the infiltration of DCs and T cells, exhibited correlations with certain forms of cell death. Subsequent experiments confirmed that UDP-G was increased in vitiligo serum and could activate DCs. We also confirmed that oxidative response is an inducer of UDP-G. In summary, the immune response in halo nevus, including DC activation, was accompanied by abnormal cell death and metabolites. Especially, melanocyte-derived UDP-G may play a crucial role in DC activation.

Spatially Decoupled H2O2 Activation Pathways and Multi-Enzyme Activities in Rod-Shaped CeO2 with Implications for Facet Distribution.

CeO2, particularly in the shape of rod, has recently gained considerable attention for its ability to mimic peroxidase (POD) and haloperoxidase (HPO). However, this multi-enzyme activities unavoidably compete for H2O2 affecting its performance in relevant applications. The lack of consensus on facet distribution in rod-shaped CeO2 further complicates the establishment of structure-activity correlations, presenting challenges for progress in the field. In this study, the HPO-like activity of rod-shaped CeO2 is successfully enhanced while maintaining its POD-like activity through a facile post-calcination method. By studying the spatial distribution of these two activities and their exclusive H2O2 activation pathways on CeO2 surfaces, this study finds that the increased HPO-like activity originated from the newly exposed (111) surface at the tip of the shortened rods after calcination, while the unchanged POD-like activity is attributed to the retained (110) surface in their lateral area. These findings not only address facet distribution discrepancies commonly reported in the literature for rod-shaped CeO2 but also offer a simple approach to enhance its antibacterial performance. This work is expected to provide atomic insights into catalytic correlations and guide the design of nanozymes with improved activity and reaction specificity.

Halo-1,2,3-triazoles: Valuable Compounds to Access Biologically Relevant Molecules.

1,2,3-triazole is an important building block in organic chemistry. It is now well known as a bioisostere for various functions, such as the amide or the ester bond, positioning it as a key pharmacophore in medicinal chemistry and it has found applications in various fields including life sciences. Attention was first focused on the synthesis of 1,4-disubstituted 1,2,3-triazole molecules however 1,4,5-trisubstituted 1,2,3-triazoles have now emerged as valuable molecules due to the possibility to expand the structural modularity. In the last decade, methods mainly derived from the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction have been developed to access halo-triazole compounds and have been applied to nucleosides, carbohydrates, peptides and proteins. In addition, late-stage modification of halo-triazole derivatives by metal-mediated cross-coupling or halo-exchange reactions offer the possibility to access highly functionalized molecules that can be used as tools for chemical biology. This review summarizes the synthesis, the functionalization, and the applications of 1,4,5-trisubstituted halo-1,2,3-triazoles in biologically relevant molecules.

Bt corn and cotton planting may benefit peanut growers by reducing aflatoxin risk.

Decades of studies have shown that Bt corn, by reducing insect damage, has lower levels of mycotoxins (fungal toxins), such as aflatoxin and fumonisin, than conventional corn. We used crop insurance data to infer that this benefit from Bt crops extends to reducing aflatoxin risk in peanuts: a non-Bt crop. In consequence, we suggest that any benefit-cost assessment of how transgenic Bt crops affect food safety should not be limited to assessing those crops alone; because the insect pest control offered by Bt crops affects the food safety profile of other crops grown nearby. Specifically, we found that higher Bt corn and Bt cotton planting rates in peanut-growing areas of the United States were associated with lower aflatoxin risk in peanuts as measured by aflatoxin-related insurance claims filed by peanut growers. Drought-related insurance claims were also lower: possibly due to Bt crops' suppression of insects that would otherwise feed on roots, rendering peanut plants more vulnerable to drought. These findings have implications for countries worldwide where policies allow Bt cotton but not Bt food crops to be grown: simply planting a Bt crop may reduce aflatoxin and drought stress in nearby food crops, resulting in a safer food supply through an inter-crop "halo effect."

The influence of the cardiac cycle on the halo sign and its impact on the ultrasound diagnosis of giant cell arteritis.

OBJECTIVES: To investigate whether hypoechoic wall thickness is influenced by the systole or diastole moment in the cardiac cycle and if this can influence ultrasound (US) assessments of giant cell arteritis (GCA). METHODS: US videos of 100 consecutive patients (50 with GCA, 50 without) performed between January 2021 and June 2023 were reviewed. Intima-media thickness (IMT) of temporal (including common trunk, frontal and parietal branches), axillary and subclavian arteries were measured at two different time points, at systolic peak (SP) and at the end-diastole (ED). Differences between SP IMT and ED IMT, as well as in the halo count (HC) and in the OMERACT GCA Ultrasonography Score (OGUS) between these two times, were analyzed. RESULTS: IMT was significantly higher (4.8-5%) at ED in all arteries, in both GCA and non-GCA groups. HC and OGUS were also higher in ED in both groups. In 4 non-GCA patients (8%), the HC was positive in ED and negative in SP; in all of them the HC in ED was 1. In the GCA group, the timing of the cardiac cycle did not influence the final US diagnosis; however, it did modify the HC in 14 patients (28%). CONCLUSION: IMT can fluctuate during the cardiac cycle, with higher measurements occurring at ED. This variability could potentially impact the accuracy of US diagnoses and assessments of GCA. If further research corroborates these findings, it may be imperative to revise the guidelines for employing US in diagnosing GCA in order to incorporate these nuanced aspects.

A novel pectin methylesterase inhibitor, PMEI3, in common bean suggests a key role of pectin methylesterification in Pseudomonas resistance.

The mechanisms underlying susceptibility to and defense against Pseudomonas syringae (Pph) of the common bean (Phaseolus vulgaris) have not yet been clarified. To investigate these, 15-day-old plants of the variety Riñón were infected with Pph and the transcriptomic changes at 2 h and 9 h post-infection were analysed. RNA-seq analysis showed an up-regulation of genes involved in defense/signaling at 2 h, most of them being down-regulated at 9 h, suggesting that Pph inhibits the transcriptomic reprogramming of the plant. This trend was also observed in the modulation of 101 cell wall-related genes. Cell wall composition changes at early stages of Pph infection were associated with homogalacturonan methylation and the formation of egg boxes. Among the cell wall genes modulated, a pectin methylesterase inhibitor 3 (PvPMEI3) gene, closely related to AtPMEI3, was detected. PvPMEI3 protein was located in the apoplast and its pectin methylesterase inhibitory activity was demonstrated. PvPMEI3 seems to be a good candidate to play a key role in Pph infection, which was supported by analysis of an Arabidopsis pmei3 mutant, which showed susceptibility to Pph, in contrast to resistant Arabidopsis Col-0 plants. These results indicate a key role of the degree of pectin methylesterification in host resistance to Pph during the first steps of the attack.

Targeted Photoactivatable Green-Emitting BODIPY Based on Directed Photooxidation-Induced Activation and its Application to Live Dynamic Super-Resolution Microscopy.

Photoactivatable fluorescent probes are valuable tools in bioimaging for tracking cells down to single molecules and for single molecule localization microscopy. For the latter application, green emitting dyes are in demand. We herein developed an efficient green-emitting photoactivatable furanyl-BODIPY (PFB) and we established a new mechanism of photoactivation called Directed Photooxidation Induced Activation (DPIA) where the furan is photo-oxidized in a directed manner by the singlet oxygen produced by the probe. The efficient photoconverter (93-fold fluorescence enhancement at 510 nm, 49% yield conversion) is functionalizable and allowed targeting of several subcellular structures and organelles, which were photoactivated in live cells. Finally, we demonstrated the potential of PFB in super-resolution imaging by performing PhotoActivated Localization Microscopy (PALM) in live cells.

Human plasmacytoid dendritic cells express the functional purinergic halo (CD39/CD73).

Plasmacytoid dendritic cells (pDCs) are a specialized DC subset mainly associated with sensing viral pathogens and high-type I interferon (IFN-I) release in response to toll-like receptor (TLR)-7 and TLR-9 signaling. Currently, pDC contribution to inflammatory responses is extensively described; nevertheless, their regulatory mechanisms require further investigation. CD39 and CD73 are ectoenzymes driving a shift from an ATP-proinflammatory milieu to an anti-inflammatory environment by converting ATP to adenosine. Although the regulatory function of the purinergic halo CD39/CD73 has been reported in some immune cells like regulatory T cells and conventional DCs, its presence in pDCs has not been examined. In this study, we uncover for the first time the expression and functionality of the purinergic halo in human blood pDCs. In healthy donors, CD39 was expressed in the cell surface of 14.0 ± 12.5% pDCs under steady-state conditions, while CD73 showed an intracellular location and was only expressed in 8.0 ± 2.2% of pDCs. Nevertheless, pDCs stimulation with a TLR-7 agonist (R848) induced increased surface expression of both molecules (43.3 ± 23.7% and 18.6 ± 9.3%, respectively), as well as high IFN-α secretion. Furthermore, exogenous ATP addition to R848-activated pDCs significantly increased adenosine generation. This effect was attributable to the superior CD73 expression and activity because blocking CD73 reduced adenosine production and improved pDC allostimulatory capabilities on CD4 + T cells. The functional expression of the purinergic halo in human pDCs described in this work opens new areas to investigate its participation in the regulatory pDC mechanisms in health and disease.

Halogenation of Anilines: Formation of Haloacetonitriles and Large-Molecule Disinfection Byproducts.

Aniline-related structures are common in anthropogenic chemicals, such as pharmaceuticals and pesticides. Compared with the widely studied phenolic compounds, anilines have received far less assessment of their disinfection byproduct (DBP) formation potential, even though anilines and phenols likely exhibit similar reactivities on their respective aromatic rings. In this study, a suite of 19 aniline compounds with varying N- and ring-substitutions were evaluated for their formation potentials of haloacetonitriles and trihalomethanes under free chlorination and free bromination conditions. Eight of the aniline compounds formed dichloroacetonitrile at yields above 0.50%; the highest yields were observed for 4-nitroaniline, 3-chloroaniline, and 4-(methylsulfonyl)aniline (1.6-2.3%). Free bromination generally resulted in greater haloacetonitrile yields with the highest yield observed for 2-ethylaniline (6.5%). The trihalomethane yields of anilines correlated with their haloacetonitrile yields. Product analysis of aniline chlorination by liquid chromatography-high-resolution mass spectrometry revealed several large-molecule DBPs, including chloroanilines, (chloro)hydroxyanilines, (chloro)benzoquinone imines, and ring-cleavage products. The product time profiles suggested that the reaction pathways include initial ring chlorination and hydroxylation, followed by the formation of benzoquinone imines that eventually led to ring cleavage. This work revealed the potential of aniline-related moieties in micropollutants as potent precursors to haloacetonitriles and other emerging large-molecule DBPs with the expected toxicity.

Structural Characterization of 6-Halo-6-Deoxycelluloses by Direct-Dissolution Solution-State NMR Spectroscopy.

Regioselective modifications of cellulose using activated cellulose derivatives such as 6-halo-6-deoxycelluloses provide a convenient approach for developing sustainable products with properties tailored to specific applications. However, maintaining precise regiochemical control of substituent distribution in 6-halo-6-deoxycelluloses is challenging due to their insolubility in most common solvents and the resulting difficulties in precise structure elucidation by modern instrumental analytical techniques. Herein, an accessible NMR-based approach toward detailed characterization of 6-halo-6-deoxycelluloses, including the determination of the degrees of substitution at carbon 6 (DS6), is presented. It is shown that the direct-dissolution cellulose solvent, tetrabutylphosphonium acetate:DMSO-d6, converts 6-halo-6-deoxycelluloses to 6-monoacetylcellulose, enabling in situ solution-state NMR measurements. A range of 1D and 2D NMR experiments is used to demonstrate the quantitivity of the conversion and provide optimum dissolution conditions. In comparison with other NMR-based derivatization protocols for elucidating the structure of 6-halo-6-deoxycelluloses, the presented approach offers major advantages in terms of accuracy, speed, and simplicity of analysis, and minimal requirements for reagents or NMR instrumentation.

Leadless pacemaker implantation using halo-shape technique in a severe dextroscoliosis octogenarian.

The halo-shape technique (HST) is an emerging approach for implanting a leadless pacemaker in scoliosis patients in recent years. Severe scoliosis and humpback made it challenging to push the tip of the delivery catheter towards the ventricular septum using the conventional gooseneck-shape technique. The feasibility and safety of the use of HST in an octogenarian with severe dextroscoliosis and humpback have not been well-assessed. Here, we report a case of high-degree atrioventricular block octogenarian with severe dextroscoliosis and humpback who successfully received a leadless pacemaker implantation using HST. Procedure-related complications were not observed, and the electrical parameters were stable at 6-month follow-up.

Indole Alkaloid Production by the Halo Blight Bacterium Treated with the Phytoalexin Genistein.

When Pseudomonas savastanoi pv. phaseolicola, the bacterium that causes halo blight, induces hypersensitive immunity in common bean leaves, salicylic acid and phytoalexins accumulate at the site of infection. Both salicylic acid and the phytoalexin resveratrol exert antibiotic activities and toxicities in vitro, adversely disrupting the P. savastanoi pv. phaseolicola proteome and metabolism and stalling replication and motility. These efficacious properties likely contribute to the cessation of bacterial spread in beans. Genistein is an isoflavonoid phytoalexin that also accumulates during bean immunity, so we tested its antibiotic potential in vitro. Quantitative proteomics revealed that genistein did not induce proteomic changes in P. savastanoi pv. phaseolicola in the same way that salicylic acid or resveratrol did. Rather, a dioxygenase that could function to metabolize genistein was among the most highly induced enzymes. Indeed, high-throughput metabolomics provided direct evidence for genistein catabolism. Metabolomics also revealed that genistein induced the bacterium to produce indole compounds, several of which had structural similarity to auxin. Additional mass spectrometry analyses proved that the bacterium produced an isomer of the auxin indole-3-acetic acid but not indole-3-acetic acid proper. These results reveal that P. savastanoi pv. phaseolicola can tolerate bean genistein and that the bacterium likely responds to bean-produced genistein during infection, using it as a signal to increase pathogenicity, possibly by altering host cell physiology or metabolism through the production of potential auxin mimics.

Characteristics of disk halo size and its correlation with lenticule quality in small incision lenticule extraction for moderate to high myopia.

PURPOSE: To investigate changes in disk halo size after small incision lenticule extraction (SMILE) and the correlation between halo size and lenticule quality in moderate to high myopia. METHODS: Thirty eyes of 30 consecutive patients (mean age, 24.9 ± 4.5 years; mean spherical equivalent, -6.85 ± 1.18 D) undergoing SMILE were included in this prospective study. Lenticule surface quality was accessed with a scanning electron microscopy by a scoring system. Halo size was measured preoperatively and at 1, 3, and 6 months postoperatively. Multiple linear regression analysis was performed to explore associations between halo size and a range of factors, including lenticule quality. RESULTS: Disk halo size increased slightly at 1 month and then recovered continually from 3 to 6 months postoperatively, with no difference between halo size during the preoperative period and at 6 months postoperatively (P > 0.05). One month after SMILE, halo size (1 cd/m2, 5 cd/m2) was associated only with uncorrected distance visual acuity (P ≤ 0.004). A halo size of 5 cd/m2 at 3 months postoperatively correlated with the anterior surface quality of the lenticule (P = 0.046). At 6 months postoperatively, a halo size of 1 cd/m2 was associated only with the baseline, accounting for 11.9% of the variability (P = 0.041); no correlations were found for the halo size of 5 cd/m2. CONCLUSIONS: Disk halo size after SMILE was enlarged at an early stage postoperatively and subsequently declined to the baseline level during a 6-month follow-up. The quality of the lenticule surface influenced halo size changes in the early phase.

Frontal correction assessment in severe adolescent idiopathic scoliosis surgery using halo gravity traction before to posterior vertebral arthrodesis: a multicenter retrospective observational study.

PURPOSE: Preoperative preparation with halo gravity traction (HGT) has several advantages but is still controversial. A multicenter, observational, retrospective study was conducted to determine whether HGT provides better frontal correction in surgery for adolescent idiopathic scoliosis (AIS). METHODS: Between 2010 and 2020, all patients who underwent posterior spinal fusion (PSF) AIS with a Cobb angle greater than 80° were included. The included patients who underwent HGT were compared (complications rate and radiographic parameters) to patients who did not undergo traction (noHGT). For patients who underwent HGT, a spinal front X-ray at the end of the traction procedure was performed. RESULTS: Sixty-four in noHGT and forty-seven in HGT group were analyzed with a 31-month mean follow-up. The mean ratio of Cobb angle correction was 58.8% in noHGT and 63.6% in HGT group (p = 0.023). In HGT, this ratio reached 9% if the traction lasted longer than 30 days (p = 0.009). The complication rate was 11.7% with a rate of 6.2% in noHGT and 19.1% in HGT group (p = 0.07). In patient whose preoperative Cobb angle was greater than 90°, the mean ratio of Cobb angle correction increases to 6.7% (p = 0.035) and the complications rate increased to 14% in the no HGT group and decreased to 13% in the HGT group (p = 0.9). CONCLUSION: HGT preparation in the management of correction of AIS with a Cobb angle greater than 90° is a technique providing a greater frontal correction gain with similar complication rate than PSF correction alone. We recommend a minimum halo duration of 4 weeks.

Risk factors for neurophysiological events related to intraoperative halo-femoral traction in spinal deformity surgery.

PURPOSE: This study identifies risk factors for neurophysiological events caused by intraoperative halo-femoral traction (IOHFT) in patients with adolescent idiopathic scoliosis (AIS), and neuromuscular scoliosis (NMS). METHODS: Neurophysiological integrity was monitored using motor evoked potentials (MEPs). IONM event was defined as a decreased MEP amplitude of more than 80% of baseline in, at least, one muscle. Time between application of IOHFT and event, affected muscles, surgical stage, and time between removal of IOHFT and recovery of MEPs were described. Characteristics (age, height, weight, diagnosis, Cobb angle, and flexibility of the curve) of patients with and without IOHFT-events were compared using analysis of variance. Binary logistic regression analyses were performed to identify predictors. RESULTS: The study included 81 patients (age 15.6 ± 2.4 years, 53 females, AIS: n = 47, NMS n = 34). IOHFT-events occurred in 11 patients (13%; AIS n = 4, NMS n = 7). IOHFTevents affecting all limbs occurred pre-incision in NMS. Events affecting only the legs occurred during all stages of surgery. Patients with IOHFT-events were smaller (p = 0.009) and had stiffer curves (p = 0.046). Height was a predictor (odds ratio, 0.941; 95% confidence interval = 0.896-0.988). All MEPs recovered after removing IOHFT. CONCLUSION: Neurophysiologic events due to IOHFT were common, with the majority in patients with NMS. A shorter stature was a risk factor, and larger Cobb angle and stiffer curve were associated with IOHFT-events. Events occurred at any stage of surgery and involved upper and lower limbs. With an adequate response on IOHFT events, none of the patients had postoperative neurological impairments due to IOHFT.

Surgical management of omega deformity in a patient with neurofibromatosis type 1: a case report.

PURPOSE: To describe the surgical treatment in a patient with a partial omega deformity in the thoracic spine with neurofibromatosis type 1. METHODS: The patient was a 55-year-old man with an omega deformity, which is defined as a curvature in which the end vertebra is positioned at the level of, above, or below the apical vertebra (i.e., a horizontal line bisecting it). We performed halo gravity traction (HGT) for 7 weeks, followed by posterior spinal instrumented nearly equal in situ fusion from T2-L5 with three femoral head allografts and a local bone autograft. We avoided reconstruction of the thoracic anterior spine because of his severe pulmonary dysfunction. RESULTS: HGT improved the % vital capacity from 32.5 to 43.5%, and improved the Cobb angle of the kyphosis from > 180° before traction to 144° after traction. The Cobb angle of kyphosis and scoliosis changed from > 180° preoperatively to 155° and 146°, respectively, postoperatively, and 167° and 156°, respectively, at final follow-up. His postoperative respiratory function deteriorated transiently due to bilateral pleural effusions and compressive atelectasis, which was successfully treated with a frequent change of position and nasal high flow for 1 week. At final follow-up, his pulmonary function improved from 0.86 to 1.04 L in VC, and from 32.5 to 37.9% in %VC. However, there was no overall improvement in preoperative distress following surgery, although his modified Borg scale improved from 3 preoperatively to 0.5 postoperatively. One month after discharge, he felt worsening respiratory distress (SpO2:75%) and was readmitted for pulmonary hypertension for 2 months. He was improved by non-invasive positive pressure ventilation (biphasic positive airway pressure) for 1 week, medication and daily lung physiotherapy. Thereafter, he has been receiving permanent daytime (0.5 L/min) and nighttime (2 L/min) oxygen therapy at home. A solid arthrodesis through the fusion area was confirmed on computed tomography. However, the kyphosis correction loss was 12° (i.e., 155°-167°), while the scoliosis correction loss was 10° (i.e., 146°-156°) at 2 years of recovery. CONCLUSIONS: We suggest that nearly equal in situ fusion is a valid option for preventing further deformity deterioration and avoiding fatal complications.

Direct evidence of a prey depletion "halo" surrounding a pelagic predator colony.

Colonially breeding birds and mammals form some of the largest gatherings of apex predators in the natural world and have provided model systems for studying mechanisms of population regulation in animals. According to one influential hypothesis, intense competition for food among large numbers of spatially constrained foragers should result in a zone of prey depletion surrounding such colonies, ultimately limiting their size. However, while indirect and theoretical support for this phenomenon, known as "Ashmole's halo," has steadily accumulated, direct evidence remains exceptionally scarce. Using a combination of vessel-based surveys and Global Positioning System tracking, we show that pelagic seabirds breeding at the tropical island that first inspired Ashmole's hypothesis do indeed deplete their primary prey species (flying fish; Exocoetidae spp.) over a considerable area, with reduced prey density detectable >150 km from the colony. The observed prey gradient was mirrored by an opposing trend in seabird foraging effort, could not be explained by confounding environmental variability, and can be approximated using a mechanistic consumption-dispersion model, incorporating realistic rates of seabird predation and random prey dispersal. Our results provide a rare view of the resource footprint of a pelagic seabird colony and reveal how aggregations of these central-place foraging, marine top predators profoundly influence the oceans that surround them.

Preoperative halo-gravity traction combined with one-stage posterior spinal fusion surgery following for severe rigid scoliosis with pulmonary dysfunction: a cohort study.

BACKGROUND: To assess the efficacy of preoperative halo-gravity traction (HGT) in treating severe spinal deformities, evaluating radiological outcomes, pulmonary function, and nutritional status. METHODS: This study retrospectively included 33 patients with severe spinal deformity who were admitted to our department from April 2018 to January 2022. All the patients underwent HGT prior to the posterior spinal fusion corrective surgery, with no patients having undergone anterior or posterior release procedures. The correction of deformity, pulmonary function tests (PFTs), and nutritional status data were collected and analyzed before and after HGT. RESULTS: A total of 33 patients (9 males, 24 females) were finally included in this study with an average age of 17.79 ± 7.96 (range 12-29) years. Among them, 20 patients were aged ≤ 16 years. The traction weight started from 1.5 kg and raised to 45.2 ± 13.2% of body weight on average progressively, with the average traction duration of 129 ± 63 days. After traction, the main curve was corrected from an average of 120.66 ± 3.89° to 94.88 ± 3.35°, and to 52.33 ± 22.36° (53%) after surgery(P < 0.05). PFTs also showed a significant increase in FVC%, FEV1%, and MEF% after traction [43.46 ± 14.76% vs. 47.33 ± 16.04%, 41.87 ± 13.68% vs. 45.19 ± 15.57%, and 40.44 ± 15.87% vs. 45.24 ± 17.91%, p < 0.05]. Total protein, albumin, and BMI were used as indicators of nutritional status. TP and albumin were significantly improved after traction, from 67.24 ± 5.43 g/L to 70.68 ± 6.98 g/L and 42.40 ± 3.44 g/L 45.72 ± 5.23 g/L, respectively(P < 0.05). No significant difference was found in deformity correction and lung function improvement between patients with traction for more or less than three months (p > 0.05). Two patients developed transient brachial plexus palsy during traction. CONCLUSIONS: Halo-gravity traction can partially correct spinal deformity, enhance pulmonary function. And HGT has been shown to facilitate an improved nutritional status in these patients. It could be used as a preoperative adjuvant treatment for severe spinal deformity. However, according to the study, a traction period longer than three months may not be necessary.