Short Intervals Research Articles

The Time Course of Injury Risk After Return-to-Play in Professional Football (Soccer).

Injury risk in professional football (soccer) is increased in the weeks following return-to-play (RTP). However, the time course of injury risk after RTP (the hazard curve) as well as its influencing factors are largely unknown. This knowledge gap, which is arguably due to the volatility of instantaneous risk when calculated for short time intervals, impedes on informed RTP decision making and post-RTP player management. This study aimed to characterize the hazard curve for non-contact time-loss injuries after RTP in male professional football and to investigate the influence of the severity of the index injury and playing position. Media-based injury records from the first German football league were collected over four seasons as previously published. Time-to-event analysis was employed for non-contact time-loss injury after RTP. The Kaplan-Meier survival function was used to calculate the cumulative hazard function, from which the continuous hazard function was retrieved by derivation. There were 1623 observed and 1520 censored events from 646 players analyzed. The overall shape of the hazard curve was compatible with an exponential decline of injury risk, from an approximately two-fold level shortly after RTP towards baseline, with a half-time of about 4weeks. Interestingly, the peak of the hazard curve was slightly delayed for moderate and more clearly for severe index injuries. The time course of injury risk after RTP (the hazard curve) can be characterized based on the Kaplan-Meier model. The shape of the hazard curve and its influencing factors are of practical as well as methodological relevance and warrant further investigation.

False-Positive Human Immunodeficiency Virus-1 Test Results With Rapid Seroreversion After Third-Trimester Tdap Booster Vaccination.

False-positive and false-negative results in human immunodeficiency virus (HIV) testing are expected at some frequency. False-positive results have been reported in association with various conditions, including pregnancy, autoimmune disease, and infection. We present an atypical case of a pregnant patient receiving false-positive HIV results for both screening and antibody confirmatory tests after a recent routine vaccination. A 34-year-old woman, G4P1021, with a negative first-trimester HIV test result received a tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) booster at 35 2/7 weeks of gestation. Test results at 36 2/7 weeks of gestation were positive in both HIV-1/2 antigen-antibody screening and a confirmatory HIV-1 antibody differentiation immunoassay, but follow-up test results at 36 5/7 weeks and later were negative. Repeat testing and erythrocyte typing confirmed that this was not a result of laboratory error or specimen mishandling. HIV antiretroviral therapy was started and was later discontinued. A scheduled primary cesarean delivery performed at 39 1/7 weeks of gestation due to breech presentation was uncomplicated. False-positive results in HIV screen and confirmation testing were associated with receipt of a Tdap vaccine booster 7 days prior. This test result pattern is similar to that seen very rarely in previous cases, and the rapid seroreversion to negative suggests an acute immunologic trigger leading to a falsely reactive antibody. Clinicians should be aware of the potential for false-positive HIV test results in patients who recently received vaccination or with other immune triggers and retest at a short interval if suspected.

Accurate surface profile measurement using CMM without estimating tip correction vectors

Detailed measurement of the curved surface of an industrial product with a radius of curvature of less than a few millimeters is a challenging task for tactile coordinate measuring machines. To estimate a surface profile, tip radius correction is typically performed by estimating the tip correction vector direction. However, a substantial measurement error is introduced by the error in estimating the tip correction vector direction under measurement conditions such as a large position measurement error of an indicated measured point or a short sampling interval, In this study, a method that can estimate a surface profile by calculating the envelope of a probe tip path was proposed. The proposed method was experimentally and numerically confirmed to be able to estimate surface profiles with sub-micrometer accuracy under such measurement conditions.

Progress of intracranial metastases during the interval before stereotactic radiosurgery, a retrospective cohort analysis

IntroductionThe incidence of intracranial metastatic disease is increasing worldwide. As a valuable treatment modality, stereotactic radiosurgery requires detailed imaging, and this study evaluated the differences between imaging obtained on the day of treatment compared to historical or referral imaging. Materials and methodsA retrospective cohort study was performed, evaluating all the patients presenting with eligible referral imaging in a 13-month period and comparing this imaging to the imaging taken on the day of treatment. Numbers of additional metastases, volumes and volume differences among the images were compared. ResultsThere was a median interval of 19 days between the acquisition of the diagnostic or referral scan and the day of treatment imaging. Even the group that had the shortest interval (up to 2 weeks) showed at least one additional deposit in 50 % of the patients. Volume was increased in 75 % of this group. Longer intervals were associated with higher increases in volume. ConclusionThese results demonstrate the increase in the disease burden in patients with intracranial metastatic disease, in relation to number and volume, in the interval between the referral and treatment imaging. This has significant implications for planning pathways, to ensure that metastatic deposits are not missed or undertreated.

Variation in 10 year birth trajectories of mothers involved in family court care proceedings and their peers in England.

ObjectiveFamily court (FC) care proceedings decide on removing children from parental care in response to concerns about risks of harm. Courts and social care report frequent births, often after short birth intervals as a key problem among mothers presenting to FCs. ApproachWe used a cohort of mothers with a first live birth (FLB) between 2007 and 2019 to estimate the cumulative incidence of FC within 10 years and compare birth trajectories with peers. Results3,118,327 women (15-50 years) had a FLB, of whom 34,062 had FC involvement. Cumulative incidence of FC within 10 years from FLB was 1.3% (95% Confidence Interval [CI]; 1.3-1.3) overall but highest in mothers who were younger (6.7% if <20 years), more deprived (2.5% in most deprived areas) and with morbidity (22.7% with learning or multiple disability, 12.8% with adversity-related injuries or 5.7% with mental health admissions). If followed for 10 years from FLB, 58.4% (8,889/15,229) of women with FC involvement had ≤2 deliveries, compared to 82.2% otherwise (1,007,365/1,225,163). If <25years at FLB, women involved in FC had more deliveries than their peers (3+ deliveries: 47.8%, 5,853/12,255 vs 29.5%, 123,092/416,904), however, if 25+, they had fewer deliveries if involved in FC (1 delivery: 49.6% 1,475/2,974 vs 39.2% 316,976/808,259). Conclusions and ImplicationsAt-risk mothers may benefit from early, targeted health and social care interventions to prevent FC involvement. Birth data highlights variation in birth trajectories and dispels the stereotype of women involved in FCs having many children, particularly if older at FLB.

Acute necrotizing encephalopathy in adult patients with influenza: a case report and review of the literature

The neurological complications of influenza affect mainly the pediatric Asian population. In the category of influenza-associated encephalopathy, acute necrotizing encephalopathy (ANE) is a rapidly progressive and fulminant brain disorder associated with significant neurological sequelae and mortality. To date, only a few adult cases of influenza-associated ANE have been reported. We describe a 44-year-old woman who presented with rapid progression of consciousness impairment and recurrent generalized convulsions. Influenza was diagnosed three days prior to presentation, and infection with influenza A (H3N2) pdm09 was subsequently confirmed. A diagnosis of ANE was made based on the presence of characteristic brain MRI findings, the exclusion of central nervous system infection, and an elevated serum interleukin-6 level. Pulse steroid therapy followed by tocilizumab was initiated, which led to clinical stabilization and improvement. Genetic testing revealed that the patient carried heterozygous human leukocyte antigen DQB1 03:03 and DRB1 09:01 genotypes. An analysis of the adult cases of influenza-associated ANE in the literature and the present case revealed a wide range of ages (22–71 years), a short interval (median 3 days) between the clinical onset of influenza and ANE, and a high overall mortality rate (32%). The thalamus was the most frequent (91%) location of the lesions. Our report highlights the importance of identifying this devastating but treatable neurological complication of influenza in adults, especially those of Asian descent. As a cytokine storm is the most accepted pathogenic mechanism for ANE, cytokine-directed therapies may be promising treatments for which further investigation is warranted.

Half-Isolated Zeros and Zero-Density Estimates

Abstract We introduce a new method to detect the zeros of the Riemann zeta function, which is sensitive to the vertical distribution of the zeros. This allows us to prove there are few “half-isolated” zeros. By combining this with classical methods, we improve the Ingham–Huxley zero-density estimate under the assumption that the non-trivial zeros of the zeta function are restricted to lie on a finite number of fixed vertical lines. This has new consequences for primes in short intervals under the same assumption.

White matter structural bases for phase accuracy during tapping synchronization.

We determined the intersubject association between the rhythmic entrainment abilities of human subjects during a synchronization-continuation tapping task (SCT) and the macro- and microstructural properties of their superficial (SWM) and deep (DWM) white matter. Diffusion-weighted images were obtained from 32 subjects who performed the SCT with auditory or visual metronomes and five tempos ranging from 550 to 950 ms. We developed a method to determine the density of short-range fibers that run underneath the cortical mantle, interconnecting nearby cortical regions (U-fibers). Notably, individual differences in the density of U-fibers in the right audiomotor system were correlated with the degree of phase accuracy between the stimuli and taps across subjects. These correlations were specific to the synchronization epoch with auditory metronomes and tempos around 1.5 Hz. In addition, a significant association was found between phase accuracy and the density and bundle diameter of the corpus callosum (CC), forming an interval-selective map where short and long intervals were behaviorally correlated with the anterior and posterior portions of the CC. These findings suggest that the structural properties of the SWM and DWM in the audiomotor system support the tapping synchronization abilities of subjects, as cortical U-fiber density is linked to the preferred tapping tempo and the bundle properties of the CC define an interval-selective topography.

New Insight of Lipiodol Flush on Pregnancy Outcomes in Women with Recurrent Implantation Failure Undergoing IVF/ICSI: a Prospective Study Based on Propensity Score Matching.

Pregnancy outcomes in women with recurrent implantation failure (RIF) undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI): does treatment with lipiodol flush matter? In this propensity score-matched study, we recruited 966 RIF patients who underwent IVF/ICSI from two tertiary hospitals. These patients were divided into groups based on whether they received lipiodol flush or not. Further stratification was applied to investigate the effect of lipiodol flush on pregnancy outcomes in RIF patients with different cycle type of embryo transferred. Then, patients subjected to lipiodol flush were categorized into three groups based on the duration of the interval: short interval (≤ 3months), moderate interval (3-6months), and long interval (≥ 6months). The groups were well-matched at baseline. The lipiodol flush group exhibited a significantly lower incidence of biochemical pregnancy (46.27% vs. 56.22%, p = 0.046) and live birth (25.87% vs. 37.31%, p = 0.014). Subgroup analysis for fresh embryo transfer cycles revealed no significant differences in pregnancy outcomes. Among RIF patients underwent frozen-thawed embryo transfer cycle, a statistically significant difference in the live birth rate was observed in the lipiodol flush group when compared to the control group (26.40% vs. 37.21%, p = 0.030). Analysis of different lipiodol flush intervals demonstrated a significantly lower live birth rate in the lipiodol flush group. Our results challenge the value of lipiodol use in clinical practice for the treatment of RIF.Trial registration: Chinese Clinical Trial Registry, ChiCTR1900024273. Registered 4 July 2019.

Treatment Outcomes in Patients with Recurrent Adrenocortical Carcinoma.

While numerous studies have explored treatment outcomes for the overall ACC patient cohort, data on the subpopulation of patients with recurrent disease are limited. Therefore, the aim of this study was to assess treatment outcomes in patients with recurrent ACC. In this retrospective study, we included 18 patients median age 49 years (42-62); 67% female) diagnosed with recurrent ENSAT stage I-III ACC who underwent either R0 (n = 16) or Rx (n = 2) surgical resection of the tumor. The median time from the initial surgery to ACC recurrence was 29 months (IQR 18-50). Seven patients (39%) manifested local recurrence, while 11 patients (61%) developed distant metastases. The median follow-up duration after tumor recurrence was 32 months (IQR 25-53). Regarding the treatment of ACC recurrence, 10 patients underwent a second surgery either as an alone procedure (n = 4), or in combination with mitotane (n = 4), mitotane and chemotherapy (n = 1), or mitotane combined with radiotherapy (n = 1). The remaining patients received treatment involving chemotherapy±mitotane (n = 4) and locoregional therapy ±chemotherapy (n = 3). One patient chose not to proceed with further management and follow-up. The median PFS was 17 (95% CI 8-26) months while the median OS was not reached. In the multivariate model, increased mortality was associated with advanced age (p = 0.04) and a shorter interval to ACC recurrence (p = 0.03). A significant proportion of patients with ACC recurrence experience disease progression or second recurrence, despite all treatment efforts. Nevertheless, by integrating diverse treatment modalities, many patients have the potential to attain long-term survival.

Bayesian frameworks for integrating petrologic and geochronologic data

Constraining the absolute time and duration of geologic processes is one of the great challenges and goals in Earth sciences. Increasingly, the integration of geochronologic constraints with petrologic information is being qualitatively applied to understanding the timescales of metamorphic, igneous, tectonic, and fluid-related processes. Many rocks and geochronometers preserve relative age constraints such as compositional zoning or cross cutting relationships. This prior information can be formalized in a Bayesian statistical framework to generate a probabilistic posterior chronology. As we show here, these “age-sequence” models can enhance precision on geochronologic dates and rates and insight into tectonic models. Bayesian modeling of complex, concentrically, zoned monazite from the northern Appalachian orogen was used to develop a detailed temperature-time history through the Acadian (∼405–395 Ma) and Neoacadian (∼380–350 Ma) orogenies with significantly reduced uncertainties (40–70 %). Modeling of zoned monazite from a southern Trans-Hudson orogen granulite yielded durations of 0.5+9/-0.4 Ma and 20+5/-8 Ma for biotite-dehydration melting and suprasolidus conditions, respectively. The relatively short intervals of heating and peak conditions are consistent with a back-arc tectonic setting. A complementary approach, Bayesian change point detection, provides a framework to constrain the timing of compositional changes that can be linked with metamorphic reactions. Applying this approach in the northern Appalachian orogen demonstrates contrasting durations of low-Y monazite crystallization (∼10 vs ∼30 myr) in regions with different pressure-temperature histories. Compositionally distinct monazite domains can be linked with garnet stability, which provides a key constraint on tectonic models. Bayesian statistical analysis represent a powerful tool that can be widely applied to refine the absolute time and duration of geologic processes. A more objective and reproducible set of interpretations are produced by this more formal, although not necessarily complex, statistical analysis.

DMD-based spatiotemporal superresolution measurement of a supersonic jet using dual planar PIV and acoustic data

The present study applies a framework of the spatiotemporal superresolution measurement based on the total-least-squares dynamic mode decomposition, the Kalman filter and the Rauch-Tung-Striebel smoother to an axisymmetric underexpanded supersonic jet of a jet Mach number of 1.35. Dual planar particle image velocimetry was utilized, and paired velocity fields of the flow with a short time interval were obtained at a temporal resolution of 5000 Hz. High-frequency acoustic data of 200,000 Hz were simultaneously obtained. Then, the time-resolved velocity fields of the supersonic jet were reconstructed at a temporal resolution of 200,000 Hz. Also, time coefficients of dynamic modes in high temporal resolution were calculated. The correlation between time coefficients implies that the mixing promotion by screech tone causes the lift-up of the high-velocity fluid from the jet center and accelerates at the downstream side.

The prevalence of short inter-pregnancy interval and its associated risk factors among women attending primary health care centers of NGHA in Jeddah, Saudi Arabia: A cross-sectional study.

The inter-pregnancy interval (IPI) refers to the time between one pregnancy and the next. Studies have shown that IPIs shorter than 18 months are linked to negative outcomes, such as preterm delivery, infant mortality, and small-for-gestational-age birth. The aim of this study was to measure the prevalence and risk factors of short inter-pregnancy intervals among women receiving care at primary health centers in Jeddah, Saudi Arabia. This is a cross-sectional study conducted at primary health care centers among mothers with a history of giving birth to at least one child and having two successive pregnancies. The data was collected through face-to-face interviews using a structured questionnaire. Statistical analysis was carried out using RStudio (R version 4.3.0). A total of 300 responses were analyzed. The prevalence of short IPI was 36.0%, 31.0% had prolonged IPI, and 33.0% had optimal IPI. Lower educational level, unemployment as a student, low or middle income, a rise in the number of children, typically more than six, and an increase in the number of male offspring, mostly four or more, lack of breastfeeding, and breastfeeding duration have all been identified as statistically significant risk factors for short IPIs. Short inter-pregnancy interval is prevalent in Jeddah city, which can negatively impact the perinatal outcomes. Addressing the risk factors and providing proper education in antenatal and postnatal clinics to reduce the number of unintended pregnancies can help in decreasing the number of short inter-pregnancy intervals and improving maternal and fetal outcomes.

Telemedicine in Post-ExposureProphylaxis to Biological Material During the COVID-19 Pandemic: Impact on Care and Outcome Indicators.

Introduction: The restrictions on face-to-face care for exposure to biological material during the COVID-19 pandemic required alternatives to maintain outpatient assistance. This study evaluated the impact of telemedicine on care and outcome indicators of a reference service for exposure to biological material during the COVID-19 pandemic. Methods: This pre- and post-study compared the effectiveness of telemedicine in the Hospital Correia Picanço in Recife (Pernambuco, Brazil) before (August 2018 to January 2019 [P1]) and during the COVID-19 pandemic (August 2020 to January 2021 [P2]). Individuals above 18 years old exposed to biological material who sought the service during P1 or P2 were included in the study. Results: A total of 4,494 cases were assessed (1,997 in P1 and 2,497 in P2), mostly because of sexual exposure (62.3%). The mean age was 32.2 ± 9.2 years, most individuals were male (64.9%), originated from Recife (56.6%), and the education level was up to 12 years (53.7%). P2 presented 43% more attendances and shorter intervals between the exposure and first attendance (51%), first testing (28%), and discharge (10%) than P1 (p < 0.05), and cases had no difference in discharge rate (p = 0.339). Cases of sexual exposure had the highest dropout rate in both periods. Conclusion: Telemedicine maintained similar outcomes to face-to-face care and improved the indicators, increasing the mean monthly attendance and reducing the time between exposure and follow-up.

Adjusting the timing of inseminations to the time lag on luteolysis alerts results in higher conception in dairy cattle

Dairy cow fertility is a complex trait that depends on the cow's physiological status, the farm's environmental and management conditions, and their interactions. Already the slightest improvement in fertility can positively impact a farm's profitability and sustainability. In research, milk progesterone (P4) has often been used as an accurate and feasible way to identify a dairy cow's reproduction status. Moreover, in Europe and Canada, it has been used to improve fertility management on commercial farms as it allows to accurately identify reproduction issues, pregnancy and the optimal insemination window. An on-farm P4 device (OPD) automatically samples, measures and monitors the milk P4 concentration of individual cows. To this end, the P4 data is smoothed to be robust for measurement errors and outliers, and fixed thresholds are used to estimate the time of luteolysis preceding ovulation, thereby generating a luteolysis alert (LA). By smoothing the P4 data, the OPD introduces a time lag on the LA. Variation in this time lag is not considered in the estimation of the optimal insemination window that is advised to the farmer. Ignoring this variation might decrease the accuracy of the optimal insemination window and, therefore, decreases the likelihood of conception. We hypothesize that considering the length of the time lag and adapting the advice accordingly improves the conception rate. This observational retrospective study uses an extensive data set from 17 commercial dairy farms that are equipped with an OPD. We estimated the time lag on the alerts and evaluated their relationship with the interval from LA to insemination for successful (n = 3721) and unsuccessful inseminations (n = 3896) separately. Results showed that the probability of conception increases when a longer LA time lag is compensated with a shorter interval from LA to insemination and vice versa. In addition, for successful inseminations, we found a clear negative relation between the time lag and the interval from LA to insemination and the interval was significantly shorter when the time lag of the LA was longer. This negative relation between time lag and interval from LA to insemination was less pronounced for unsuccessful inseminations. Additionally, we evaluated the conception rates for inseminations that are performed too early, in time or too late with respect to the optimal insemination window advised by the OPD, in function of their associated time lags. We found that, for inseminations that were preceded by a short time lag (<8 h), the conception rate was 17.5 percentage points higher when cows were inseminated later than advised. Likewise, when inseminations were preceded by a long time lag (≥24 h), we found that the conception rate was 13 percentage points higher when cows were inseminated earlier than advised. Our results suggest that farmers using an OPD could potentially increase their conception success by compensating the variable time lag on the LA by adapting the interval from alert to insemination accordingly. This could be used to develop reproductive management strategies to improve reproductive performance on those farms, which can positively impact their sustainability.

Localized and Long-Lasting Adaptation in Dragonfly Target-Detecting Neurons.

Some visual neurons in the dragonfly (Hemicordulia tau) optic lobe respond to small, moving targets, likely underlying their fast pursuit of prey and conspecifics. In response to repetitive targets presented at short intervals, the spiking activity of these "small target motion detector" (STMD) neurons diminishes over time. Previous experiments limited this adaptation by including intertrial rest periods of varying durations. However, the characteristics of this effect have never been quantified. Here, using extracellular recording techniques lasting for several hours, we quantified both the spatial and temporal properties of STMD adaptation. We found that the time course of adaptation was variable across STMD units. In any one STMD, a repeated series led to more rapid adaptation, a minor accumulative effect more akin to habituation. Following an adapting stimulus, responses recovered quickly, though the rate of recovery decreased nonlinearly over time. We found that the region of adaptation is highly localized, with targets displaced by ∼2.5° eliciting a naive response. Higher frequencies of target stimulation converged to lower levels of sustained response activity. We determined that adaptation itself is a target-tuned property, not elicited by moving bars or luminance flicker. As STMD adaptation is a localized phenomenon, dependent on recent history, it is likely to play an important role in closed-loop behavior where a target is foveated in a localized region for extended periods of the pursuit duration.

Children and Adolescent Patients with Variants in the ATP1A3 -encoded Sodium-Potassium ATPase Alpha-3 Subunit Demonstrate an Impaired QT Response to Bradycardia and Predisposition to Sinus Node Dysfunction.

Alternating hemiplegia of childhood (AHC) is a rare disorder with both neurologic and cardiac manifestations. The ATP1A3-D801N variant is associated with a pathologically short QT interval and risk of ventricular arrhythmia following bradycardia; however, the mechanism of this remains unknown. We investigated the relationship between heart rate (HR), QT, and QTc, hypothesizing that individuals with ATP1A3-D801N have abnormal, impaired shortening of QT and QTc at lower HR leading to arrhythmia predisposition. We performed a retrospective observational study of individuals who underwent clinical evaluation, Holter monitoring, and genetic testing for AHC at Duke University Hospitals. We also compiled a group of healthy individuals as a control cohort. A larger, worldwide cohort of individuals with ATP1A3 - related phenotypes was compiled to investigate sinus node dysfunction. Linear regression analysis was then performed. The cohort consisted of 44 individuals with ATP1A3 -related phenotypes with 81 Holter recordings (52.27% female; mean age at first Holter 8.04 years, range 0.58 - 33 years), compared to 36 healthy individuals with 57 Holter recordings (52.78% female; mean age at first Holter 9.84 years, range 0.08 - 38 years). Individuals with ATP1A3-D801N had reduced prolongation of QT at lower HR, manifest as a significantly lower slope for HR vs QT compared to healthy (P<0.0001). This resulted in a significantly higher slope of the relationship for HR vs QTc compared to healthy (P<0.0001). Individuals with ATP1A3 - related phenotypes and baseline QTc <350 milliseconds (ms) had increased shortening of QT and QTc at lower HR compared to those with normal QTc (P=0.003; P=0.001). Among worldwide cases, 3 out of 131 individuals with ATP1A3 -related phenotypes required device implantation and/or had sinus pauses >4 seconds. Individuals with the ATP1A3-D801N variant exhibit paradoxical shortening of QT and QTc at lower HR, which contribute to an increased risk of arrhythmias during bradycardia. This is exacerbated by an underlying risk of sinus node dysfunction. What is Known: Individuals with ATP1A3-D801N have a short baseline QTc.Two individuals with AHC experienced ventricular fibrillation following bradycardia. What the Study Adds: The QT and QTc shorten to a greater extent at lower heart rate in individuals with ATP1A3-D801N than in healthy individuals. Individuals with ATP1A3 -related phenotypes and QTc <350ms show greater impairment of QT and QTc dynamics than those with normal QTc. There is low prevalence of device implantation and significant sinus pauses in individuals with ATP1A3 -related phenotypes, with a relatively greater prevalence in those with ATP1A3-D801N.

Interval to Recurrence Affects Survival in Recurrent Head and Neck Squamous Cell Carcinoma.

Approximately half of head and neck squamous cell carcinoma (HNSCC) cases recur, with most recurrences occurring within the first two years after treatment. Although it has been suggested that the interval to recurrence after radical treatment is associated with prognosis in patients with HNSCC, further investigation is needed. Patients diagnosed with HNSCC at Kyushu University Hospital were retrospectively analyzed (n=500). Early recurrence (ER) was defined as disease recurrence within six months of radical treatment, whereas late recurrence (LR) was defined as recurrence after more than six months. Continuous variables were assessed using the Mann-Whitney U-test and categorical variables were assessed using Fisher's exact test. A total of 234 patients experienced recurrence, with 110 and 124 patients experiencing ER (recurrence within two to six months) and LR (recurrence after six months), respectively. Multivariate analyses identified two independent risk factors for poor prognosis: ER [hazard ratio (HR)=3.200, 95% confidence interval (CI)=1.570-6.521, p=0.001] and absence of radiotherapy (HR=0.374, 95%CI=0.191-0.733, p=0.004). In patients with recurrent HNSCC, a short interval to recurrence is a risk factor for poor prognosis and survival. This study demonstrated the prognostic value of ER in these patients. The selection of treatment for patients with recurrent head and neck squamous cell carcinoma should consider the timing of recurrence, the initial treatment regimen, and the strategy for changing salvage therapy depending on the recurrence status.

406. EXPLORING THE OPTIMAL TIMING OF MINIMALLY INVASIVE SURGERY FOR ESOPHAGEAL SQUAMOUS CELL CARCINOMA AFTER NEOADJUVANT CHEMORADIOTHERAPY

Abstract Background Neoadjuvant chemoradiotherapy has gradually become a first-line treatment for esophageal squamous cell carcinoma patients. After the completion of neoadjuvant chemoradiotherapy, patients usually undergo minimally invasive surgery to ensure complete removal of the tumor and lymphatic tissue. However, the optimal interval between neoadjuvant chemoradiotherapy and minimally invasive surgery is still an unknown factor, and whether it affects postoperative disease-free survival (DFS) and overall survival (OS) of patients remains unknown. Therefore, the main purpose of this study is to explore the specific impact of the interval between neoadjuvant chemoradiotherapy and minimally invasive surgery on patients, and to find the optimal interval time. Methods Patients who underwent neoadjuvant chemoradiotherapy and minimally invasive surgery from two institutions between October 2012 and September 2022 were included in this study. The time interval is defined as the days between the last time a patient receives neoadjuvant chemoradiotherapy and the execution of surgery. Determine the optimal interval truncation point using the surv_cutpoint function in the survminer package. The main research result is the OS and DFS of different interval groups. A multivariate Cox regression model was established to determine the main factors affecting Patient's OS. Construct a nomogram based on selected factors to meet clinical needs. Results 252 patients were included in the study. The average interval between patients undergoing neoadjuvant chemoradiotherapy and minimally invasive surgery is 59 days. The earliest interval for patients to undergo surgery is 28 days. Determine the optimal interval of 46 days based on the survminer package and divide the patients into two groups. The five-year OS rates for the short interval group and the long interval group were 82.6% and 61.0% (P = 0.023). The five-year DFS rates for the two groups were 67.6% and 48.2% (P=0.068). Multivariate Cox regression shows that the time interval, patient's sex, tumor differentiation, ypT, and ypN are the main factors affecting overall survival. Conclusions The interval between neoadjuvant chemoradiotherapy and minimally invasive surgery has a certain impact on patient survival, and it is recommended to undergo surgery between 28 and 46 days to improve patient prognosis and survival.

Short Interval Repeat Colonoscopy After Inadequate Bowel Preparation Is Low Among Veterans

Short Interval Repeat Colonoscopy After Inadequate Bowel Preparation Is Low Among Veterans