Early Interval Research Articles

Relationships between oxygen changes in the brain and periphery following physiological activation and the actions of heroin and cocaine

Using two-sensor electrochemical recordings in freely moving rats, we examined the relationship between physiological and drug-induced oxygen fluctuations in the brain and periphery. Animals chronically implanted with oxygen sensors in the nucleus accumbens (NAc) and subcutaneous (SC) space were subjected to several mildly arousing stimuli (sound, tail-pinch and social interaction) and intravenous injections of cocaine and heroin. Arousing stimuli induced rapid increases in NAc oxygen levels followed by and correlated with oxygen decreases in the SC space. Therefore, cerebral vasodilation that increases cerebral blood flow and oxygen entry into brain tissue results from both direct neuronal activation and peripheral vasoconstriction, which redistributes arterial blood from periphery to the brain. The latter factor could also explain a similar pattern of oxygen responses found in the substantia nigra reticulata, suggesting hyperoxia as a global phenomenon with minor structural differences during early time intervals following the stimulus onset. While arousing stimuli and cocaine induced similar oxygen responses in the brain and SC space, heroin induced a biphasic down-up brain oxygen fluctuation associated with a monophasic oxygen decrease in the SC space. Oxygen decreases occurred more rapidly and stronger in the SC space, reflecting a drop in blood oxygen levels due to respiratory depression.

Upper Ordovician (Hirnantian) to Lower Silurian (Telychian, Llandovery) graptolite biostratigraphy of the Tielugou section, Shennongjia anticline, Hubei Province, China

The Tielugou section, Shennongjia Anticline, Hubei Province (China) includes a relatively complete succession of Hirnantian (latest Ordovician) to basal Telychian (Llandovery, early Silurian) graptolite faunas. The section shows the first record of a fauna of the late Aeronian Stimulograptus halli Biozone from South China, even though the index species was not reported. The Stimulograptus sedgwickii Biozone may not be represented, indicating a possible gap at the base of the Stimulograptus halli Biozone. The interval yields a number of taxa that are elsewhere reported to originate only in the Stimulograptus halli Biozone. The youngest graptolitic levels are included in the Spirograptus guerichi Biozone based on specimens of Parapetalolithus dignus and Parapetalolithus palmeus not known from earlier intervals. Spirograptus guerichi is not represented in the section. The Tielugou section provides the first detailed information on the faunas and thickness of the encountered biostratigraphic units for the Shennongija region.

A long-term follow-up analysis of associations between tooth loss and multiple cancers in the Linxian General Population cohort

Poor oral health, indicated by tooth loss and periodontal disease, may be an important risk factor for various cancers. Prior studies have found inconsistent associations between tooth loss and several cancer types. Here, we examined the relationship between tooth loss and incident cases of multiple cancers in the Linxian General Population Nutrition Intervention Trial cohort. In this large prospective cohort of over 29,000 participants, there were 3101, 1701, 626, 327, 348, and 179 incident esophageal, gastric cardia, gastric noncardia, liver, lung, and colorectal cancer cases, respectively, over 30 years of follow-up. Adjusted Cox proportional hazards regression models with time-varying covariates were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between tooth loss and cancer outcomes during three time intervals: ≤ 5 years (early), > 5 and ≤ 10 years (mid), > 10 years (late). Tooth loss was assessed as quartiles of the number of lost teeth in excess of the loess-smoothed, age-specific median number of teeth lost. For esophageal cancer, the increase in risk associated with the highest quartile of tooth loss was 25% (95% CI: 1.02, 1.52) in the mid time interval, but the association weakened thereafter. For gastric cardia cancer, the increase in risk associated with the highest quartile of tooth loss was 1.34 in both the early (95% CI: 1.06, 1.71) and mid time intervals (95% CI: 1.02, 1.76), with no significant associations in the late interval. Gastric noncardia cancer was only associated with the second quartile of tooth loss in the late time interval (HR = 1.54; 95% CI: 1.16, 2.04). All associations between tooth loss and liver, lung, and colorectal cancers were null. Tooth loss was associated with risk of esophageal and gastric cancers in this updated analysis from the cohort.

Timing of corticosteroids impacts mortality in hospitalized COVID-19 patients.

The optimal timing of initiating corticosteroid treatment in hospitalized patients is unknown. We aimed to assess the relationship between timing of initial corticosteroid treatment and in-hospital mortality in COVID-19 patients. In this observational study through medical record analysis, we quantified the mortality benefit of corticosteroids in two equally matched groups of hospitalized COVID-19 patients. We subsequently evaluated the timing of initiating corticosteroids and its effect on mortality in all patients receiving corticosteroids. Demographic, clinical, and laboratory variables were collected and employed for multivariable regression analyses. 1461 hospitalized patients with confirmed COVID-19 were analyzed. Of these, 760 were also matched into two equal groups based on having received corticosteroid therapy. Patients receiving corticosteroids had a lower risk of death than those who did not (HR 0.67, 95% CI 0.67–0.90; p = 0.01). Timing of corticosteroids was assessed for all 615 patients receiving corticosteroids during admission. Patients receiving first dose of corticosteroids > 72 h into hospitalization had a lower risk of death compared to patients with first dose at earlier time intervals (HR 0.56, 95% CI 0.38–0.82; p = 0.003). There was a mortality benefit in patients with > 7 days of symptom onset to initiation of corticosteroids (HR 0.56, 95% CI 0.33–0.95; p = 0.03). In patients receiving oxygen therapy, corticosteroids reduced risk of death in mechanically ventilated patients (HR 0.38, 95% CI 0.24–0.60; p < 0.001) but not in patients on high-flow or other oxygen therapy (HR 0.46, 95% CI 0.20–1.07; p = 0.07) and (HR 0.84, 95% CI 0.35–2.00; p = 0.69), respectively. Timing of corticosteroids initiation was related to in-hospital mortality for COVID-19 patients. Time from symptom onset > 7 days should trigger initiation of corticosteroids. In the absence of invasive mechanical ventilation, corticosteroids should be initiated if the patient remains hospitalized at 72 h. Hypoxia requiring supplemental oxygen therapy should not be a trigger for initiation of corticosteroids unless the timing is appropriate.

Changes in basement membrane components in an experimental model of skeletal muscle degeneration and regeneration induced by snake venom and myotoxic phospholipase A2

Skeletal muscle regeneration is impaired after myonecrosis induced by viperid snake venoms, but the mechanisms behind such poor regenerative outcome are not fully understood. This study compared the changes in basement membrane (BM) components in mouse skeletal muscle in two different scenarios of muscle injury: (a) injection of Bothrops asper venom, as a model of poor regeneration, and (b) injection of a myotoxic fraction (Mtx) isolated from this venom, as a model of successful regeneration. The degradation and reposition of laminin, type IV collagen and fibronectin were assessed over time by a combination of immunohistochemistry, Western blot, and real time polymerase chain reaction. Both treatments induced degradation of laminin and type IV collagen in areas of muscle necrosis since day one, however, there were differences in the pattern of degradation and reposition of these proteins along time. Overall, Mtx induced a higher synthesis of fibronectin and higher degradation of laminin at intermediate time points, together with higher levels of transcripts for the chains of the three proteins. Instead, venom induced a higher degradation of laminin and type IV collagen at early time intervals, followed by a reduced recovery of type IV collagen by 15 days. These differences in extracellular matrix degradation and remodeling between the two models could be associated to the poor muscle regeneration after myonecrosis induced by B. asper venom.

Adaptations of Coccolithophore Size to Selective Pressures During the Oligocene to Early Miocene High CO2 World

AbstractCulture experiments with coccolithophore algae—the dominant group of marine calcifying phytoplankton—imply a strong sensitivity in growth rate, degree of cellular calcification, and cell size to changes in the carbon chemistry of their growth environment. These results underpin recent studies that have explored how these physiological parameters have varied on geological time scales, in response to changing surface ocean habitats and the concentrations of carbon in the ocean‐atmosphere system. Here, we add to this work with a study of reticulofenestrid coccolith size—the dominant coccolithophore family of the Cenozoic—over the Oligocene to Early Miocene time interval. We examine sediments from contrasting latitudes and regional environmental settings, comparing sites using coherent, updated age models to distinguish globally synchronous trends in cell size from regional trends. Our results confirm several changes in coccolith size—which is strongly correlated to cell size—that are globally reproducible within the ~1 Myr age uncertainty, including a reduction in mean size by &gt;2 μm from 30.2 to 27 and 24.5 to 23 Ma, and then increase in mean size after 20 Ma. The main difference among regions is the presence/absence of coccoliths larger than 8 μm. We evaluate which scenarios of change in carbon dioxide, temperature, and nutrient availability could have exerted selective pressure on cell size for different size classes to produce the observed size trends at each studied site. These million‐year scale adaptations of ancient coccolithophores contribute to the understanding of phytoplankton physiology in the transition to the modern “icehouse” world.

Abstract 16115: The Society of Cardiovascular Angiography and Interventions Cardiogenic Shock Classification Predicts Mortality in Cardiac Arrest Patients Prior to Pci

Introduction: Acute coronary syndrome (ACS) complicated by cardiac arrest (CA) has a heterogeneous presentation, and risk can be challenging to stratify. This study aimed to apply the SCAI cardiogenic shock stages to patients with ACS complicated by CA at early pivotal time intervals when prompt interventions may have a greater impact. Methods: Patients undergoing PCI presenting with CA were stratified according to the SCAI shock classification, retrospectively, on arrival to the cardiac catheterization laboratory (CCL) and on arrival to the intensive care unit (ICU). The primary end-point was in-hospital mortality. Secondary end-points were mortality stratified by the use of mechanical circulatory support or the level of vasopressor support used. Results: Between 01/2014 -08/2018, seventy-nine patients presented with ACS complicated by a CA. The mean age was 70 (SD ± 12) years, and 19 (24%) were females. On arrival to the CCL 17 (22%) were stage A, 6 (8%) were stage B, 31 (40%) were stage C, 19 (24%) were stage D, and 6 (8%) were stage E. In general, there was a stepwise increase in mortality with increasing stage (A 35% vs. B 16% vs. C 48% vs. D 68% vs. E 83%; p=0.05). There was a similar trend when stratified on arrival to the ICU (Figure 1), although of marginal statistical significance (P = 0.07). Presentation with shock stage D or E to the CCL was predictive of mortality (OR 3.7 CI 1.3-10.5; p=0.01) on logistic regression models. The use of mechanical support was not associated with increased mortality. However, the use of an Impella in patients requiring high vasopressor support at arrival to the CCL was associated with a trend towards decreased mortality (25% vs. 61%, p=0.18). Conclusion: Increasing SCAI shock stages on arrival to the CCL and ICU is associated with increased in-hospital mortality among patients who presented after a CA and underwent PCI. The SCAI classification at defined time points has the potential to serve as an important research tool.

Plantar flexor strength at different knee positions in older and young males and females.

This study examined the effects of age and knee position (fully extended, K0; 90° flexed, K90) on plantar flexor maximal voluntary contraction (MVC) torque and the rate of torque development (RTD) in both sexes. The following parameters were measured in 32 older (66-81yr, 17 males and 15 females) and 37 young (20-30yr, 18 males and 19 females) adults: evoked peak twitch torque, time to peak twitch torque, RTD of the twitch torque, MVC torque, RTD at early (0-50ms, RTD0-50) and later (100-200ms, RTD100-200) time intervals during explosive contractions, voluntary activation (VA%) during MVC, root mean square of the electromyogram (RMS-EMG) during MVC and explosive contractions, thickness of the triceps surae, and pennation angle of the medial gastrocnemius. The magnitudes of the differences were interpreted based on Cohen's d (d). Age-related difference in RTD0-50 was greater for females (d=1.36) than males (d=1.03) and vice versa for MVC torque and RTD100-200. For young adults, MVC torque, RTDs, and RMS-EMGs of the gastrocnemius but not the soleus were significantly higher in K0 than in K90. For older adults, no differences in voluntary RTDs were observed between K0 and K90, and RMS-EMGs of the gastrocnemius were higher in K90 than in K0, except for that of the lateral gastrocnemius in the early time intervals during explosive contraction. The age-related difference in the effect of knee position for RTD0-50 was higher in females than males, and vice versa for MVC torque and RTD100-200. The results suggested that the effects of age and knee joint angle on the plantar flexor performance were more prominent in the early phase of force production for females and were more apparent in the later phase and maximal force for males.

Early gonadal maturation and vitellogenin mRNA expression in Siberian sturgeon Acipenser baerii cultured in a semi-closed water recirculating system in Korea

Changes of gonadal morphology and mRNA expression patterns of vitellogenin were investigated in Siberian sturgeon Acipenser baerii (Chondrostei) during its early gonadal maturation period. Early differentiations and morphological transitions of both ovaries and testes appeared to occur actively until the age of 3 years, however from then on, the maturation patterns to full maturity were largely gender-dependent, in which males showed a faster progression of maturation than did females while females experienced a steady-state progress with a lagged interval before entering the final maturation. Expression of vitellogenin mRNAs are closely correlated with transitional patterns of gonadal appearances. In both females and males, hepatic mRNA levels of vitellogenin exponentially increased in the earliest interval (up to 1-year-old). However, in subsequent periods, vitellogenin expression in females continued to increase with age, whereas in males, the expression stabilized at a younger age. Nevertheless, at the age older than or equal to 7-year-old, fully matured individuals showed a quite low level of vitellogenin expression in both females and males. Collectively, results from this study could be useful as a fundamental guideline to address the gonad maturation of this sturgeon species, which is helpful for making practical decisions about farming practices and management for caviar production on local sturgeon farms.

193. Biomimetic 3D-printed titanium-alloy interbody spacers demonstrate uniform bone growth over 12 weeks

BACKGROUND CONTEXT A primary clinical outcome of interbody fusion surgery is achievement of bony fusion. Polyetheretherkeytone (PEEK) and titanium-alloy (TAV) have been used for years as interbody implant materials, although each material has unique drawbacks related to visualization, stiffness, and biocompatibility. Due to advancements in 3D printing technology, titanium-alloy (TAV) interbody spacers can be made with complex and innovative designs, such as a porous structure that mimics the architecture of trabecular bone. Implants with a microscale surface roughness and a biomimetic, porous structure may promote formation of new bone. A uniform rate of bone formation during healing may lead to optimized fusion. PURPOSE The purpose of this study was to compare bone growth rate (BGR) following lateral lumbar interbody fusion (LLIF) between interbody fusion devices made from polyetheretherketone (PEEK), titanium-alloy (TAV), and 3D-printed biomimetic titanium-alloy (3DP) interbody implants in an ovine model. STUDY DESIGN/SETTING In Vivo animal study. PATIENT SAMPLE N/A OUTCOME MEASURES Microcomputed tomography was used to quantify bone volume (BV) and the BGR within the spacers at three time points. Postoperative time points were 6 and 12 weeks. BV at the initial postoperative time point (0 weeks) was also quantified by implanting cadaver sheep with autograft bone packed spacers (n=4 levels per group). METHODS Eighteen sheep underwent a two-level (L2–L3 and L4–L5) LLIF using PEEK, TAV or 3DP spacers (n=6 levels per group per time point). Animals were sacrificed at 6 and 12 weeks postoperatively. BGR was calculated for each treatment group between the three time points. RESULTS The 3DP-treated group demonstrated a more consistent BGR over 12 weeks compared to PEEK and TAV groups. The BGR for the 3DP group was 10.6 mm3/week and 9.6 mm3/week from 0 to 6 weeks and 6 to 12 weeks, respectively. Bone growth in PEEK and TAV groups was delayed, evidenced by not surpassing the remodeling phase until after 6 weeks. Additionally, PEEK and TAV groups had an inconsistent BGR between early and late time intervals (PEEK: 1.5 and 17.0mm3/week, respectively; TAV: -2.1 and 17.7mm3/week, respectively). CONCLUSIONS This study demonstrated porous, biomimetic 3DP TAV interbody spacers led to robust intervertebral fusion. 3DP implants facilitated uniform bone growth through the spacers over 12 weeks, evidenced by lower bone volume observed with PEEK and TAV implants at 6 weeks. This data suggests that porous, biomimetic 3DP spacers are a favorable alternative to PEEK and TAV for interbody fusion, promoting a uniform rate of bone growth over 12 weeks. FDA DEVICE/DRUG STATUS HEDRON (Globus Medical) (Approved for this indication)

Reliability of calcareous nannofossil events in the Tithonian–early Berriasian time interval: Implications for a revised high resolution zonation

The latest Jurassic was a crucial time for calcareous nannoplankton as a major speciation episode took place with the appearance and rapid evolution of several new genera and species, particularly of highly calcified nannoliths at low latitudes: this origination pulse provides the opportunity to achieve high-resolution biostratigraphic data amplifying the possibility of dating and correlating.A thorough revision of published as well as newly updated nannofossil biostratigraphies across the Tithonian–lowermost Berriasian interval was achieved to quantitatively evaluate the reliability of individual nannofossil events. Our database comprises 95 land and oceanic sites from different paleogeographic settings and latitudes (Europe, Atlantic Ocean, America, South Asia). We excluded sections with hiatuses or characterized by uncertain calcareous nannofossil biostratigraphy due to scarcity of data and/or poor preservation, as well as taxonomic incongruities. For each stratigraphic section, the critical assessment took into account sampling rates, nannofossil preservation, abundance and taxonomy: biohorizons based on single samples, questionably determined, or based on ambiguous/mismatching taxonomic concepts were excluded. We first performed calibration of nannofossil events against magnetostratigraphy to highlight reproducibility and time variability through the CM22–CM17 interval. The time uncertainties of individual nannofossil events were calculated, considering sampling and sedimentation rates derived from magnetostratigraphy. The reproducibility and variability of nannofossil events were also estimated relative to calpionellid biostratigraphy, as the latter is the primary tool selected by the Berriasian Working Group (ICS) for the definition of the Cretaceous base.We distinguished highly reliable events characterized by maximum reproducibility, shorter time variability, common and continuous occurrence; moderately reliable events are distinguished by intermediate reproducibility and time variability; unreliable events have minimum reproducibility and longest time variability.The quantitative evaluation of 37 events against magnetostratigraphy in the CM22–CM17 interval allowed to discriminate among 9 highly reliable first occurrences, 4 reliable first occurrences, 10 moderately reliable events (7 first occurrences, 2 last occurrences and 1 last common occurrence), 6 poorly reliable events (5 first occurrences and 1 last occurrence) and 8 unreliable first occurrences. The evaluation of 18 events against the calpionellid zonation resulted in 4 highly reliable first occurrences.The revisited taxonomy and reliability assessment of calcareous nannofossil events were used to revise the calcareous nannofossil zonation of the Tithonian–early Berriasian time interval: one zone (NC 0 Zone) and four subzones (NC 0a, NC 0b, NJT 14a, NJT 14b Subzones) are newly defined here. Moreover, one zonal definition is emended (NJT 17 Zone) and the age of top/bases of four zones (NJT 14, NJT 15; NJT 16, NC 1 Zones) are revised. The first appearance datum of Nannoconus wintereri, showing the highest reproducibility and lowest time variability, correlates with magnetochron 19n-2n and results to be the calcareous nannofossil event best approximating the base of the Calpionella alpina Zone equated to the Jurassic/Cretaceous boundary.

Bone volume change following vascularized free bone flap reconstruction of the mandible

BackgroundBone volume changes following vascularized bone flaps and possible confounding factors over time are described in the literature with some controversy. The purpose of this study was to evaluate the bone volume behavior of two frequently used free flaps. Materials and methodsComputed tomography (CT) scans were examined with regard to bone volume using the software program ITK-SNAP for all patients who required mandibular reconstruction with a free fibula flap (FFF, conventionally vs assisted by computer-aided design/computer-aided manufacturing (CAD/CAM)) or iliac crest flap (DCIA) following mandibular resection because of benign or malign processes, between August 2010 and August 2015. Clinical data, complication rates, and CT scans were analyzed retrospectively. Additionally, complication rates (microvascular revision, flap loss, postoperative fistula or dehiscence, and postoperative bone exposure) were compared within early (≤30 days), late (31st–100th day), and overall (≤100th day) postoperative time intervals. Results113 cases, comprizing 89 FFF and 24 DCIA cases, were included. FFF showed superior bone volume behavior over the DCIA flap. Multivariable regression models assessed the relationships between the following and bone volume behavior: interval between operation and CT scan (p < 0.683), age (p = 0.004), gender (p = 0.006), BMI (p = 0.400), adjuvant radiation therapy (p = 0.334), reconstruction with DCIA flap (p < 0.0001), number of segments (p = 0.02), and incidence of dental implant insertion (p = 0.45). ConclusionsThe bone volume of FFFs remains stable. DCIA flaps show a higher bone volume reduction, but the postoperative course might be associated with fewer complications. Time interval between operation and CT scan, age, gender, reconstruction with DCIA flap, and number of fibula segments contributed significantly to bone volume behavior.

Biscutum constans coccolith size patterns across the mid Cretaceous in the western Tethys: Paleoecological implications

The morphometric record of the calcareous nannofossil species Biscutum constans from the western Tethys indicates that this species underwent marked size changes across the latest Barremian-Cenomanian interval (~ 28 Myrs). Significant size reduction occurred during the core of the early Aptian Oceanic Anoxic Event (OAE) 1a (~ 120 Ma) and soon after OAE 1a followed by a 9 Myr-long interval characterized by small specimens. Larger coccoliths marked the middle to late Albian and, particularly, the lower part of the nannofossil subzone NC10a was characterized by abundant large specimens. A minor size decrease coincided with the late Albian OAE 1d onset (~ 100 Ma), but very small size was reached again during the latest Cenomanian OAE 2 (~ 94.4 Ma). The sequence of relatively long (millions of years) intervals marked by different average sizes is interpreted to reflect adaptation to changing paleoecological conditions. Temperature and fertility were not directly influencing the size of B. constans. On shorter time scale, abrupt changes in ocean chemistry related to Large Igneous Provinces submarine volcanism played a central role in secretion of small B. constans coccoliths to face ocean acidification during OAE 1a and OAE 2. Contrarily, during the late early Aptian-early Albian time interval, smaller B. constans size was related to cooler temperature which possibly also promoted CO2 sequestration in cooler surface waters forcing B. constans to produce small coccoliths to survive lowered pH. In addition, pulses of subaerial volcanism of the Southern Kerguelen Plateau may have further affected the ocean chemistry. The termination of intense volcanism and warmer temperature in the middle Albian-early Cenomanian coincided with restoration of bigger B. constans specimens.

New middle and late Smithian ammonoid faunas from the Utah/Arizona border: New evidence for calibrating Early Triassic transgressive-regressive trends and paleobiogeographical signals in the western USA basin

New Smithian (Early Triassic) ammonoid assemblages were sampled near the Utah/Arizona border. They provide several spatiotemporal constraints on the regional Sinbad Formation showing that the extent of the Smithian sea in the southwestern-most part of the western USA basin is larger than previously expected, reaching northern Arizona and an area just east of Kanab in Kane County, Utah. This southwestern-most excursion of the sea in the western USA basin is part of the third order Smithian transgression-regression cycle, which is well-documented worldwide. These new spatiotemporal constraints also indicate that the Sinbad Formation spans the late middle to early late Smithian time interval in the studied area. The observed transgressive trend corresponds to the warm temperatures of the middle-early late Smithian and the regressive trend to the cooling phase spanning the Smithian-Spathian transition. Thus, the Sinbad Formation and its marine deposits are the direct result of global climatic fluctuations and related sea-level changes that occurred from the late middle Smithian to the Smithian-Spathian transition. This highlights the importance of the Sinbad Formation in untangling local and global changes occurring around the late Smithian, and thus in overcoming a major obstacle to the understanding of the biotic recovery after the Permian/Triassic boundary mass extinction. This also indirectly confirms that the western USA basin is a key area containing essential information for the understanding of the Early Triassic events. The taxonomic richness of late middle Smithian assemblages is much lower in the studied area than in the more northern localities. However, the occurring taxa confirm the known regional to global distribution of Smithian ammonoids, witnessing the major global environmental changes from the middle Smithian to the early Spathian.

Serial Assessment of Body Fat and Fat-Free Mass Accretion in Very Preterm Infants: A Randomized Trial

Abstract Objectives To incorporate assessment of body composition in the routine care of preterm infants to guide feeding practices before and after hospital discharge. Methods Very preterm infants with gestational ages between 29 and 32 weeks of gestation were included. Infants with gastrointestinal or neurologic malformations and terminal illness needing to limit or withhold support were excluded. All study participants were eligible for serial assessments of body composition between birth and 32 weeks PMA, at 36 weeks PMA or hospital discharge, and at 3 months of corrected age. Infants randomly assigned to the intervention group had the information about infant body composition available to the clinicians caring for them (including reference data). Infants randomly assigned to the control group also underwent serial assessments, but this information on infant body composition was not shown to the clinicians caring for them. The primary outcome was % body fat (%BF) estimated by air displacement plethysmography. Results Fifty very preterm infants were randomized. Mean birthweight of study participants was 1387 g +/– SD 283 and median gestational age at birth was 30 weeks (IQR: 30 – 31). Sociodemographic characteristics did not differ between groups. Mean %BF between birth and 32 weeks PMA (n = 45) was 6 +/– 4, mean %BF at 36 weeks PMA (n = 35) was 14 +/– 4, and mean %BF at 3 months of corrected age (n = 25) was 20 +/– 4. Mean differences in %BF between the intervention group and the control group were not statistically significant at 36 weeks PMA (−0.8) or 3 months corrected age (−1.2). Similarly, feeding practices during hospitalization did not differ between groups. Growth outcomes did not differ between groups. Conclusions Serial assessments of body composition at birth, 36 weeks PMA, and 3 months corrected age in very preterm infants show increased %BF in both intervention and control groups without an apparent influence of the intervention on feeding practices. While 36 weeks PMA has been a common assessment point for research purposes, body composition assessments may need to be done at earlier intervals in order to make meaningful clinical changes to the infant diet in order to affect body composition later in infancy. Funding Sources UAB OHDRC.

Abstract TMP91: Pre-Sepsis P-wave Terminal Force in Lead V1 (PTFV1) as a Predictor of Atrial Fibrillation, In-Hospital Mortality, and Cognition in Sepsis Patients

Introduction: Enlarged P-wave terminal force in lead V1 (PTFV1) &gt;5000 μV*ms is a long-term predictor of the left atrial abnormality such as atrial fibrillation (AF), cognitive dysfunction, and stroke at age ≤ 60. Sepsis patients are at high risk of cardiac dysfunction, AF, stroke, and impaired cognition acutely and longitudinally, but predictive value pre-sepsis PTFV1 has not been studied. Hypothesis: Higher PTFV1 before sepsis onset is associated with AF events, left atrial enlargement, mortality, and 1-year cognitive impairment in patients who developed sepsis. Methods: Patients with acute sepsis were prospectively screened and enrolled in an observational study years 2015-2019. Of the 360 consented, 287 had pre-sepsis electrocardiograms (ECG), and 272 were evaluable. PTFV1 was measured using the Mitutoyo 500-195-30CAL Absolute Digimatic Caliper. Left atrial diameter index (LADI) pre-sepsis and post enrollment were recorded (median of 2 days [interquartile range (IQR) 1-13]). Occurrence of AF was assessed on the next available ECG, 3 days [IQR 1-11] post-enrollment. Cognitive function at 1-year follow-up was assessed by the mini-mental state examination (MMSE) and the Hopkins Verbal Learning test (HVLT). Statistical significance was evaluated using linear and logistic univariate regression. Results: In this cohort, the median age was 63 years [IQR 53-71], 44% women. The median PTVF1, LADI at pre-sepsis and follow up were 3219 μV*ms [IQR 0 - 5487], 1.86 cm/mm 2 [IQR 1.58 - 2.14], and 1.89 cm/mm 2 [IQR 1.59 - 2.17], respectively. Pre-sepsis PTFV1 was &gt; 5,000 μV*ms in 32%. Elevated PTFV1 at age ≥ 60 was not associated with AF (p=0.06) or in-hospital mortality (p=0.17). Similarly, high PTFV1 at age &lt; 60 was not associated in-hospital mortality (p=0.50), and only 3 in this cohort had AF. There was no association with pre-sepsis LADI (p=0.55), follow-up LADI (p=0.70), MMSE (p=0.35), or HVLT (p=0.78) and PTFV1. Conclusions: Here, PTFV1 values were not associated with AF or measures of cognitive impairment. While our findings differ from other longitudinal studies, the early time interval and setting of sepsis in our study is unique. Future studies will include multivariate analysis and evaluation of long term outcome measures linked to PTFV1 such as stroke.

Comparison of the effects of audio-instructed and video-instructed dispatcher-assisted cardiopulmonary resuscitation on resuscitation outcomes after out-of-hospital cardiac arrest

BackgroundThis study compared the real-world effects of audio-instructed dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) and video-instructed DA-CPR on resuscitation outcomes after out-of-hospital cardiac arrest (OHCA). MethodsA retrospective cohort study was conducted among adult OHCA patients in whom resuscitation was attempted in 2017 in Seoul, Korea. The dispatch center of Seoul introduced video-instructed DA-CPR in 2017, whereas audio-instructed DA-CPR was first implemented in 2010. When more than two bystanders were at the scene and could handle a video-call, the dispatcher call back a video-call and provided CPR instructions. In other situations, standard audio-instructed DA-CPR was provided. The primary outcome was survival to discharge. The secondary outcome was good neurological outcome at hospital discharge. The tertiary outcome was early instruction time interval (ITI, time from call to the initiation of CPR instruction ≤90 s). The study outcomes of audio-instructed DA-CPR (audio group) and video-instructed DA-CPR (video group) were compared. The propensity score matching (PSM) method was used to increase the comparability of the two groups and the logistic regression was performed for the PSM cohort. ResultsA total of 1720 eligible OHCA patients (1489 and 231 in the audio and video groups, respectively) were evaluated. The median ITI was 136 s in the audio group and 122 s in the video group (p = 0.12). The survival to discharge rates were 8.9% in the audio group and 14.3% in the video groups (p < 0.01). Good neurological outcome occurred in 5.8% and 10.4% in the audio and video groups, respectively (p < 0.01). Compared to the audio group, the AORs (95% CIs) for survival to discharge, good neurological outcome and early ITI of the video group were 1.20 (0.74–1.94), 1.28 (0.73–2.26) and 1.00 (0.70–1.43), respectively. The PSM population showed similar results as those of the original cohort. ConclusionCompared to audio-instructed DA-CPR, video-instructed DA-CPR was not associated with survival improvement in this observational study conducted in one metropolitan city. Randomized controlled trials are needed to compare the effects of video- and audio-instructed DA-CPR.

Abstract 457: Comparison of Effect of Audio-Instructed and Video-Instructed Dispatcher-Assisted Cardiopulmonary Resuscitation on Resuscitation Outcomes After Out-Of-Hospital Cardiac Arrest

Introduction: This study aimed to compare the effect of audio-instructed dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) and video-instructed DA-CPR on resuscitation outcome after out-of-hospital cardiac arrest (OHCA) in the real world. Methods: A cross-sectional study was conducted for resuscitation-attempted adult OHCAs of 2017 in Seoul, Korea. Seoul implemented video-instructed DA-CPR program in 2017. According to the protocol, when dispatcher detected OHCA, they checked two condition: 1) more than two bystanders were in the scene, 2) they could handle a video-call. If both conditions were met, dispatcher initiated the CPR instruction and called back a video-call to the caller for instructing CPR via video (video group). Unless, standard audio-instructed DA-CPR was provided (audio group). The primary outcome was survival to discharge. The secondary outcome was good neurological outcome at hospital discharge. The tertiary outcome was early instruction time interval (ITI, time from call to the initiation of CPR instruction≤ 90 seconds). The study outcomes were compared between audio and video group. A multivariable logistic regression analysis was performed and adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were calculated adjusting for potential confounders. Propensity score matching (PSM) method was used to increase comparability of two groups and same logistic regression model was analyzed for the PSM population. Results: A total of 1,720 eligible OHCA cases (1,489 in audio and 231 in video group) were evaluated. The median seconds of ITI was 136 seconds in audio group and 122 seconds in the video group (p=0.12). Survival to discharge was 8.9% in audio group and 14.3% in video group (p&lt;0.01). Good neurological outcome was 5.8% in audio group and 10.4% in video group (p&lt;0.01). Compared with audio group, the AORs (95% CIs) for survival to discharge, good neurological outcome and early ITI of the video group were 1.20 (0.74 to 1.94), 1.28 (0.73 to 2.26) and 1.00 (0.70 t0 1.43), respectively. PSM population showed similar results with original population. Conclusion: Compared with audio-instructed DA-CPR, video-instructed DA-CPR was not associated with survival improvement in the observational study.

Depositional Environment and Sequence Stratigraphy of the Oligocene-Miocene Deposits North and East of Dehdasht, Izeh Zone, Zagros Basin, Iran

In this study, four well-exposed outcrops of the Asmari Fm in the southeastern part of the Izeh Zone of the Zagros Mountains were measured and sampled. In this region, the Asmari Fm is Oligocene to Early Miocene in age as determined by large benthic foraminifera. Based on depositional geometries, biogenic contents and lateral and vertical variations of facies, three depositional models are proposed to illustrate the evolution of the Asmari carbonate platform. During the Chattian, large benthic foraminifera and coral-coralline red algae were dominant, while through the Early Miocene time interval (Aquitanian-Burdigalian), non-skeletal components along with porcelaneous foraminifera were the most conspicuous elements. These deposits formed a carbonate ramp in the Chattian and a low angle carbonate-ramp during the Early Miocene. Five major 3rd-order depositional sequences have been identified based on stratal stacking patterns and facies relationships. These depositional sequences show systematic progradations from SE to NW into and over the basinal Pabdeh Fm during Oligo-Miocene times.

Evaluation of nonlinear optical behavior of mouse colon cancer cell line CT26 in hyperthermia treatment.

Hyperthermia treatment can induce component changes on cell. This study explored the potential of Z-scan to improve accuracy in the identification of subtle differences in mouse colon cancer cell line CT26 during hyperthermia treatment. Twenty-one samples were subjected individually to treatment of hyperthermia at 41, 43, and 45°C. Each hyperthermia treatment was done in six different time (15, 30, 45, 60, 75, and 90min). Two optical setups were used to investigate the linear and nonlinear optical behavior of samples. Prior to the Z-scan technique, all samples were fixed with 1mL of 5% paraformaldehyde. The linear optical setup indicated that extinction coefficient cannot monitor cell changes at different treatment regimes. But the nonlinear behavior of CT26 in all hyperthermia treatment regimens was different. By increasing the time and/or temperature of hyperthermia treatments, change in the sign of nonlinear refractive index from negative to positive occurred in earlier time intervals. This phenomenon was seen for 41, 43, and 45°C in 75, 60, and 45min, respectively. The results showed that the Z-scan technique is a reliable method with the potential to characterize cell changes during hyperthermia treatment regimes. Nonlinear refractive index can be used as a new index for evaluation of cell damage.