Sacroiliitis in inflammatory bowel disease on abdominal computed tomography: prevalence, misses, and associated factors

OBJECTIVE

To evaluate the prevalence and rate of a missed diagnosis of sacroiliitis on abdominal computed tomography (CT) in patients with inflammatory bowel disease (IBD). Factors associated with sacroiliitis were also assessed.

METHOD

This retrospective study included 210 patients with IBD (mean age 31.1 years) who underwent abdominal CT. Based on a validated abdominal CT scoring tool, bilateral sacroiliac (SI) joints on abdominal CT in the whole study population were retrospectively reviewed. Subsequently, patients were classified into the 'patients with sacroiliitis' group and the 'patients without sacroiliitis' group. Univariate and multivariate regression analyses were used to clarify the factors associated with sacroiliitis.

RESULTS

Sacroiliitis was identified in 26 out of 210 patients (12.4%). However, sacroiliitis was recognized on the primary reading in only five of these 26 patients (19.2%) and was missed on the initial report in the remaining 21 patients (80.8%). Among the 21 patients, 20 (95.2%) were finally diagnosed with axial spondyloarthritis (axSpA). There was a higher prevalence of female sex (p = 0.04), upper gastrointestinal involvement (p = 0.04), and back pain (p < 0.01) in patients with sacroiliitis than in those without sacroiliitis. However, on multivariate analysis, back pain was the only factor associated with sacroiliitis (p = 0.01).

CONCLUSION

Physicians should carefully evaluate SI joints on abdominal CT in patients with IBD to enable early detection of sacroiliitis, potentially leading to an early diagnosis of axSpA. In addition, if patients with IBD present with back pain, the possibility of sacroiliitis should be considered.

Position paper on olfactory dysfunction: 2023

BACKGROUND

Since publication of the original Position Paper on Olfactory Dysfunction in 2017 (PPOD-17), the personal and societal burden of olfactory disorders has come sharply into focus through the lens of the COVID-19 pandemic. Clinicians, scientists and the public are now more aware of the importance of olfaction, and the impact of its dysfunction on quality of life, nutrition, social relationships and mental health. Accordingly, new basic, translational and clinical research has resulted in significant progress since the PPOD-17. In this updated document, we present and discuss currently available evidence for the diagnosis and management of olfactory dysfunction. Major updates to the current version include, amongst others: new recommendations on olfactory related terminology; new imaging recommendations; new sections on qualitative OD and COVID-19 OD; updated management section. Recommendations were agreed by all co-authors using a modified Delphi process.

CONCLUSIONS

We have provided an overview of current evidence and expert-agreed recommendations for the definition, investigation, and management of OD. As for our original Position Paper, we hope that this updated document will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency, and generalisability of work in this field.

A Phase II Trial Evaluating Rapid Mid-Treatment Nodal Shrinkage to Select for Adaptive Deescalation in p16+ Oropharyngeal Cancer Patients Undergoing Definitive Chemoradiation

PURPOSE/OBJECTIVE(S)

The purpose of this study is to determine if rapid mid-treatment nodal shrinkage (RMNS) can identify patients with p16+ oropharyngeal cancer (OPC) who can be safely deescalated with reduced dose chemoradiation therapy (CRT). The primary endpoint was 2-year progression free survival (PFS).

MATERIALS/METHODS

Inclusion criteria were as follows: T1-3, N1, M0 (AJCC 8th edition) p16+ OPC with <10 pack-year smoking history. All patients were initially planned for standard dose CRT (70 Gy) and weekly cisplatin. Patients were evaluated with a CT scan at week 4 for RMNS, defined as >40% nodal volumetric reduction from baseline. If RMNS was achieved, they proceeded to deescalated CRT (60 Gy). If not, they received standard CRT. Biomarker correlates were collected at baseline and week 4 of CRT including plasma TTMV (tumor tissue modified viral) HPV DNA and MRI diffusion weighted imaging (DWI). Univariate logistic regression analyses (UVA) were performed to evaluate predictors of RMNS. Odds ratios with 95% CI are reported, using a p<0.05 for statistical significance with a two-sided test. Wilcoxon rank sum tests were used to evaluate differences between the two groups using p < 0.05, 2-sided) for statistical significance. All statistical procedures were performed using R () with no adjustments for multiple testing.

RESULTS

Thirty-six patients were enrolled: median age: 60 years; 81% male; primary site: 36% base of tongue, 53% tonsil, 11% both; T-stage: 39% T1, 50% T2, 11% T3; N-stage: 100% N1; any smoking history: 58% yes, 42% no; 67% (n = 24) had RMNS and received deescalated CRT while the remaining proceeded to standard CRT. At a median follow-up of 32.4 months, 2-year PFS between the standard and deescalated groups were 91.7% vs 90.9%, respectively (p = 0.97). All patients with recurrence underwent successful salvage treatment with 2-year OS 100% for all patients. On UVA, rapid TTMV HPV DNA clearance (baseline to week 4) (OR 12.0 [1.65-250], p = 0.034), lower MRI diffusivity (ADC) at baseline (OR 0.79 [0.61-0.97], p = 0.042) and week 4 (OR 0.76 [0.60-0.91], p = 0.009), and higher MRI diffusional kurtosis at baseline (OR 1.09 [1.01-1.21], p = 0.051) and week 4 (OR 1.24 [1.09-1.52], p = 0.009) were significantly associated with RMNS. When comparing the deescalated and standard cohorts, the mean baseline and week 4 MRI ADC were significantly lower and week 4 MRI diffusional kurtosis was significantly higher in the deescalated group.

CONCLUSION

In this phase II study, rapid mid-treatment nodal shrinkage appeared to select favorable risk p16+ oropharynx cancer patients for treatment de-escalation. Rapid clearance of TTMV HPV DNA at week 4 as well as MRI DWI biomarkers of low ADC and high diffusional kurtosis values were correlated with RMNS. A larger study is planned to incorporate RMNS and biomarkers for further treatment de-escalation. Additional trial information is available at ClinicalTrials.gov (Identifier: NCT03215719).

Can Acupuncture be a Part of the Treatment for Breast Cancer-Related Lymphedema? A Systematic Review of the Safety and Proposed Model for Care

Acupuncture is a potential therapy for breast cancer-related lymphedema (BCRL). Despite a recent meta-analysis on efficacy, data on acupuncture safety in BCRL are lacking. Current clinical guidelines recommend avoiding needling in the upper extremity affected by lymph node dissection. We undertook a systematic review focusing on acupuncture safety and treatment protocols in clinical trials for BCRL. Literature searches were conducted in PubMed, Ovid, CINAHL, and Cochrane library. Eight clinical trials on acupuncture for BCRL were analyzed. The Standards of Acupuncture intervention (STRICTA 2010) and Cochrane risk of bias (RoB2 2019) were applied to assess methods for acupuncture interventions within Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework. Quantity and severity of adverse events (AE) were reviewed. A total of 189 subjects participated in 8 clinical trials with 2965 acupuncture treatments. No serious adverse events (SAE) were reported regardless of treatment laterality or protocol, with only a single grade 2 skin infection in 2,965 total treatments (0.034%), including 1,165 bilateral and 225 ipsilateral treatments. Our comprehensive review of clinical trials of acupuncture for BCRL demonstrated no significant adverse events in 2,965 treatments, including 1,390 in the affected limb. An approach for routine integration of acupuncture into BCRL maintenance therapy is proposed.

Arterial Baroreflex Inhibits Muscle Metaboreflex Induced Increases in Effective Arterial Elastance: Implications for Ventricular-Vascular Coupling

The ventricular-vascular relationship assesses the efficacy of energy transferred from the left ventricle to the systemic circulation and is quantified as the ratio of effective arterial elastance to maximal left ventricular elastance. This relationship is maintained during exercise via reflex increases in cardiovascular performance raising both arterial and ventricular elastance in parallel. These changes are, in part, due to reflexes engendered by activation of metabosensitive skeletal muscle afferents-termed the muscle metaboreflex. However, in heart failure, ventricular-vascular uncoupling is apparent and muscle metaboreflex activation worsens this relationship through enhanced systemic vasoconstriction markedly increasing effective arterial elastance which is unaccompanied by substantial increases in ventricular function. This enhanced arterial vasoconstriction is, in part, due to significant reductions in cardiac performance induced by heart failure causing over-stimulation of the metaboreflex due to under perfusion of active skeletal muscle, but also as a result of reduced baroreflex buffering of the muscle metaboreflex-induced peripheral sympatho-activation. To what extent the arterial baroreflex modifies the metaboreflex-induced changes in effective arterial elastance is unknown. We investigated in chronically instrumented conscious canines if removal of baroreflex input via sino-aortic baroreceptor denervation (SAD) would significantly enhance effective arterial elastance in normal animals and whether this would be amplified after induction of heart failure. We observed that effective arterial elastance (E_a), was significantly increased during muscle metaboreflex activation after SAD (0.4 ± 0.1 mmHg/mL to 1.4 ± 0.3 mmHg/mL). In heart failure, metaboreflex activation caused exaggerated increases in E_a and in this setting, SAD significantly increased the rise in E_a elicited by muscle metaboreflex activation (1.3 ± 0.3 mmHg/mL to 2.3 ± 0.3 mmHg/mL). Thus, we conclude that the arterial baroreflex does buffer muscle metaboreflex induced increases in E_a and this buffering likely has effects on the ventricular-vascular coupling.

Prognostic implication of left atrial strain in patients undergoing totally thoracoscopic ablation of atrial fibrillation

Background

Atrial fibrillation (AF) is a common form of arrhythmia and associated with poor quality of life. Totally thoracoscopic ablation (TTA) is a novel minimally invasive strategy for symptomatic atrial fibrillation (AF) refractory to other therapy. However, some of patients undergoing TTA are still exposed to a risk of AF recurrence.

Purpose

The aim of this study is to investigate prognostic factors related with AF recurrence after TTA, and to determine the prognostic implication of left atrial (LA) strain in this population.

Methods

This was a prospective observational study. Between February 2012 and March 2015, left atrial appendage (LAA) was harvested from patients who underwent TTA in our Medical Center. Degree of LAA fibrosis was expressed as the percentage of area of positive collagen staining in the total area of the image of specimen. All echocardiographic parameters were measured in preoperative echocardiography. The primary outcome was any recurrence of AF detected in 12- lead electrocardiogram or holter monitoring during 5 years of follow-up.

Results

Out of 150 patients who underwent TTA during the study period, 129 were eligible for analysis with appropriate surgery, LAA specimen, and echocardiographic images. A mean age was 54.4±8.8 years, and 123 patients (95.3%) were male. Twenty four patients (18.6%) had paroxysmal AF and a mean CHA2DS2 VASc score was 1.1±1.2. A median value of peak longitudinal LA strain (reservoir strain) was 15.2% (IQR 12.1–19.2), and the median value of LAA fibrosis was 38.5% (IQR 33.0–44.7). Among clinical and echocardiographic variables, peak longitudinal LA strain (p&lt;0.001) and left ventricular ejection fraction (p=0.044) were significantly associated with degree of LAA fibrosis (Figure). Of 129 patients, 47 (36.4%) experienced recurrent AF during the median 3.9 years of follow-up. In a multivariable Cox regression analysis using clinical, echocardiographic and operative parameters, peak longitudinal LA stain was the only predictor of recurrent AF (adjusted HR 0.89, 95% CI 0.81–0.98, p=0.024; Table).

Conclusions

Peak longitudinal LA strain was associated with LAA fibrosis, and was a significant predictor of recurrent AF after TTA

Funding Acknowledgement

Type of funding sources: None.

Viral stimulation modulates endotype-related ACE2 expression in eosinophilic chronic rhinosinusitis

BACKGROUND

Angiotensin-converting enzyme 2 (ACE2), a receptor targeted by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is highly expressed in the nasal mucosa. Chronic rhinosinusitis (CRS) shows diverse endotypes and is aggravated by viral infection. Whether viral stimulation and CRS endotype influence ACE2 expression remains unclear. We investigated the expression of ACE2 and the transmembrane protease, serine 2 (TMPRSS2), which mediate the entry of SARS-CoV-2 into cells, and assessed polyinosinic:polycytidylic acid (poly[I:C])-induced changes based on CRS endotype.

METHODOLOGY

ACE2 and TMPRSS2 expression was evaluated based on CRS phenotype, endotype, and tissue type. Correlations between ACE2/TMPRSS2 expression and inflammatory mediators in nasal polyps (NP) were examined. Air-liquid interface culture experiments were performed to assess the effects of major cytokines or poly(I:C) stimulation on ACE2/TMPRSS2 expression in primary epithelial cells from healthy nasal mucosa, eosinophilic NP (ENP), and non-eosinophilic NP (NENP).

RESULTS

In primary nasal epithelial cells, interleukin (IL)-13 decreased ACE2 expression but increased TMPRSS2. Eosinophilic CRS showed lower ACE2 expression than non-eosinophilic CRS, regardless of CRS phenotype. CRS endotype was an independent factor associated with ACE2/TMPRSS2 expression in NP. Serum and tissue eosinophilic marker levels were inversely correlated with ACE2 expression, whereas tissue neutrophilic marker levels and ACE2 expression were positively correlated in NP. ACE2 expression was suppressed in ENP tissues; however, a combination of poly(I:C) and IL-13 induced ACE2/TMPRSS2 upregulation in ENP.

CONCLUSIONS

ENP tissues have lower ACE2 expression than NENP; however, viral stimulation promotes ACE2/TMPRSS2 upregulation in ENP.

Effects of chronic dietary grape seed extract supplementation on aortic stiffness and hemodynamic responses in obese/overweight males during submaximal exercise

We investigated the effect of chronic grape seed extract (GSE) on blood pressure and aortic stiffness (AoS) among overweight and obese males. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), stroke volume (SV), cardiac output (Q), total vascular conductance (TVC), and AoS were measured during two submaximal cycling exercises (40% and 60% VO_2max), after 7 consecutive days of GSE or placebo (PL) ingestion with one week washout period. Compared with PL, GSE supplementation significantly decreased MAP at rest (85 ± 3 mmHg vs. 82 ± 3 mmHg), 40% (102 ± 3 mmHg vs. 99 ± 3 mmHg), and 60% workloads (109 ± 3 mmHg vs. 107 ± 3 mmHg) (P = 0.001, ES = 0.2). AoS was significantly reduced (13.0 ± 1.9 AU vs. 10.2 ± 1.0 AU) at rest (P = 0.002, ES = 0.6). Q was decreased at rest and across all workloads, but there were no significant differences (7.5 ± 0.4 L/min vs. 7.1 ± 0.4 L/min; 20.4 ± 1.2 L/min vs. 19.6 ± 0.9 L/min; 26.3 ± 1.1 L/min vs. 25.5 ± 1.6 L/min, respectively). GSE had no effect on HR, TVC, and SV. Our study indicates that chronic supplementation with GSE reduces arterial pressure at rest and during exercise primarily via the substantial reduction in AoS. Thus, GSE can be a dietary supplement to treat augmented blood pressure responses in obese and overweight males at rest and during exercise.Trial registration: ClinicalTrials.gov identifier: NCT04465110.

Subepithelial neutrophil infiltration as a predictor of the surgical outcome of chronic rhinosinusitis with nasal polyps

BACKGROUND

Neutrophils present as major inflammatory cells in refractory chronic rhinosinusitis with nasal polyps (CRSwNP), regardless of the endotype. However, their role in the pathophysiology of CRSwNP remains poorly understood. We investigated factors predicting the surgical outcomes of CRSwNP patients with focus on neutrophilic localization.

METHODS

We employed machine-learning methods such as the decision tree and random forest models to predict the surgical outcomes of CRSwNP. Immunofluorescence analysis was conducted to detect human neutrophil elastase (HNE), Bcl-2, and Ki-67 in NP tissues. We counted the immunofluorescence-positive cells and divided them into three groups based on the infiltrated area, namely, epithelial, subepithelial, and perivascular groups.

RESULTS

On machine learning, the decision tree algorithm demonstrated that the number of subepithelial HNE-positive cells, Lund-Mackay (LM) scores, and endotype (eosinophilic or non-eosinophilic) were the most important predictors of surgical outcomes in CRSwNP patients. Additionally, the random forest algorithm showed that, after ranking the mean decrease in the Gini index or the accuracy of each factor, the top three ranking factors associated with surgical outcomes were the LM score, age, and number of subepithelial HNE-positive cells. In terms of cellular proliferation, immunofluorescence analysis revealed that Ki-67/HNE-double positive and Bcl-2/HNE-double positive cells were significantly increased in the subepithelial area in refractory CRSwNP.

CONCLUSION

Our machine-learning approach and immunofluorescence analysis demonstrated that subepithelial neutrophils in NP tissues had a high expression of Ki-67 and could serve as a cellular biomarker for predicting surgical outcomes in CRSwNP patients.

Radiomics-based model for predicting pathological complete response to neoadjuvant chemotherapy in muscle-invasive bladder cancer

AIM

To develop and validate a radiomics-based model for predicting response to neoadjuvant chemotherapy (NAC) using baseline computed tomography (CT) images in patients with muscle-invasive bladder cancer (MIBC).

MATERIALS AND METHODS

A radiomics signature for predicting pathological complete response (pCR) was developed using radiomics features selected by a random forest classifier on baseline CT images, and imaging predictors were identified in the training set (87 patients). By incorporating imaging predictors and radiomics signature, an imaging-based model was constructed using multivariate logistic regression analysis and validated in an independent validation set consisting of 48 patients with CT from outside institutions. The performance and clinical usefulness of the imaging-based model for predicting pCR were evaluated using area under the receiver operating characteristic curve (AUC) and decision curve analysis. Using a cut-off determined in the training set, the positive likelihood ratios of the imaging-based model were calculated and compared with imaging and histological predictors.

RESULTS

The radiomics signature was developed based on six stable radiomics features. An imaging-based model incorporating radiomics signature, tumour shape, tumour size, and clinical stage showed good performance for predicting pCR in both the training (AUC, 0.85; 95% confidence interval [CI], 0.78-0.93) and validation (AUC, 0.75; 95% CI, 0.60-0.86) sets, providing a larger net benefit in decision curve analysis. The imaging-based model showed a higher positive likelihood ratio (1.91) for pCR than imaging and histological predictors (1.33-1.63).

CONCLUSIONS

The radiomics-based model using baseline CT images may predict the response of patients with MIBC to NAC.

Timing and clinical outcomes of tracheostomy in patients with COVID-19

In this retrospective multicentre cohort study that included 27 COVID-19 patients who underwent tracheostomy, the mean time between intubation and tracheostomy was 15.8 days and the negative conversion time of COVID-19 was 43.1 days. Eleven patients (40.7%) died of COVID-19 and the use of percutaneous dilatation tracheostomy was significantly associated with in-hospital death. Timely tracheostomy could be performed in COVID-19 patients, regardless of duration of intubation or positivity of COVID-19 test, with an open surgical tracheostomy as a preferable technique.

Physiological and Biomechanical Differences Between Seated and Standing Uphill Cycling

Despite differences in economy, cyclists climb in seated and standing positions. Prompted by gaps in research, we compared VO2 and heart rate (HR) (Study 1), muscle activation (Study 2) and breathing and pedaling entrainment (Study 3).

METHODS

Subjects rode their bicycles on a treadmill in seated and standing positions. In Study 1, VO2 and HR of four male cyclists (21.3 ± 1.7 yrs; 69.1 ± 6 ml/kg/min) were collected, alternating positions every 5 minutes for 20 minutes (8 mph, 8% grade). In Study 2, muscle activations of eight male cyclists (24 ± 5 yrs, 67.6 ± 5.5 ml/kg/min) were collected on Rectus Femoris (RF), Biceps Femoris, Vastus Medialis (VM) and Gastrocnemius alternating positions every minute (8 mph, 8% grade). In Study 3, flow rate and entrainment of nine male cyclists (28 ± 7 yrs, 62.7 ± 7.7 ml/kg/min) were collected in 2-minute stages at 6, 8 and 10 mph, (8% grade) alternating positions every minute.

RESULTS

VO2 and HR increased standing (3.17± 0.43 L/min, 175 ± 4 bpm) compared to seated (3.06 ± 0.37 L/min, 166 ± 5 bpm) (p < 0.05). Normalized EMG for RF and VM increased standing (47 ± 5%, 57 ± 15%) compared to seated (34 ± 3%, 36 ± 8%) (p < 0.05). Peak Inspiratory and Expiratory Flow increased standing (3.44±0.07 and 2.45±0.05 L/sec) compared to seated (3.09 ±0.06 and 2.21±0.04 L/sec) (p < 0.05).

CONCLUSION

Uphill cycling while standing results in decreased cycling economy due to physiological and biomechanical variations compared to riding seated.

Montel mirror based collimating analyzer system for high-pressure resonant inelastic X-ray scattering experiments

Resonant inelastic X-ray scattering (RIXS) is increasingly playing a significant role in studying highly correlated systems, especially since it was proven capable of measuring low-energy magnetic excitations. However, despite high expectations for experimental evidence of novel magnetic phases at high pressure, unequivocal low-energy spectral signatures remain obscured by extrinsic scattering from material surrounding the sample in a diamond anvil cell (DAC): pressure media, Be gasket and the diamond anvils themselves. A scattered X-ray collimation based medium-energy resolution (∼100 meV) analyzer system for a RIXS spectrometer at the Ir L₃-absorption edge has been designed and built to remediate these difficulties. Due to the confocal nature of the analyzer system, the majority of extrinsic scattering is rejected, yielding a clean low-energy excitation spectrum of an iridate Sr₂IrO₄ sample in a DAC cell. Furthermore, the energy resolution of different configurations of the collimating and analyzing optics are discussed.

Impact of inversion symmetry on a quasi-1D S = 1 system

Here, we report the synthesis and magnetic properties of a novel, centrosymmetric, quasi-1D spin chain system La₃VWS₃O₆, with hexagonal crystal structure (P6₃/m, a  =  9.460 76(3), c  =  5.518 09(2) Å). Pure powders were obtained by solid-state reactions from La₂O₃, WO₃ and metal powders of V and W. X-ray powder diffraction, specific heat, magnetization, ¹³⁹La-nuclear magnetic resonance (NMR), and electric resistivity measurements indicate that the compound is a low dimensional magnet with an S  =  1 spin chain that exhibits no sign of magnetic ordering above 2 K. A single ion anisotropy (D/k _B ~ 10 K), caused by magneto-crystalline effects, is probably responsible for a thermodynamic entropy release at lower temperatures, which concurs with ¹³⁹La-NMR data. By detailed comparison with non-centrosymmetric Ba₃V₂S₄O₃, having a very similar magnetic lattice, it is obvious that the presence of crystallographic inversion symmetry has an effect on the behaviour of the magnetic chains.

The organ-specific differential roles of rice DXS and DXR, the first two enzymes of the MEP pathway, in carotenoid metabolism in Oryza sativa leaves and seeds

BACKGROUND

Deoxyxylulose 5-phosphate synthase (DXS) and deoxyxylulose 5-phosphate reductoisomerase (DXR) are the enzymes that catalyze the first two enzyme steps of the methylerythritol 4-phosphate (MEP) pathway to supply the isoprene building-blocks of carotenoids. Plant DXR and DXS enzymes have been reported to function differently depending on the plant species. In this study, the differential roles of rice DXS and DXR genes in carotenoid metabolism were investigated.

RESULTS

The accumulation of carotenoids in rice seeds co-expressing OsDXS2 and stPAC was largely enhanced by 3.4-fold relative to the stPAC seeds and 315.3-fold relative to non-transgenic (NT) seeds, while the overexpression of each OsDXS2 or OsDXR caused no positive effect on the accumulation of either carotenoids or chlorophylls in leaves and seeds, suggesting that OsDXS2 functions as a rate-limiting enzyme supplying IPP/DMAPPs to seed carotenoid metabolism, but OsDXR doesn't in either leaves or seeds. The expressions of OsDXS1, OsPSY1, OsPSY2, and OsBCH2 genes were upregulated regardless of the reductions of chlorophylls and carotenoids in leaves; however, there was no significant change in the expression of most carotenogenic genes, even though there was a 315.3-fold increase in the amount of carotenoid in rice seeds. These non-proportional expression patterns in leaves and seeds suggest that those metabolic changes of carotenoids were associated with overexpression of the OsDXS2, OsDXR and stPAC transgenes, and the capacities of the intermediate biosynthetic enzymes might be much more important for those metabolic alterations than the transcript levels of intermediate biosynthetic genes are. Taken together, we propose a 'Three Faucets and Cisterns Model' about the relationship among the rate-limiting enzymes OsDXSs, OsPSYs, and OsBCHs as a "Faucet", the biosynthetic capacity of intermediate metabolites as a "Cistern", and the carotenoid accumulations as the content of "Cistern".

CONCLUSION

Our study suggests that OsDXS2 plays an important role as a rate-limiting enzyme supplying IPP/DMAPPs to the seed-carotenoid accumulation, and rice seed carotenoid metabolism could be largely enhanced without any significant transcriptional alteration of carotenogenic genes. Finally, the "Three Faucets and Cisterns model" presents the extenuating circumstance to elucidate rice seed carotenoid metabolism.

Effects of combined histamine H1 and H2 receptor blockade on hemodynamic responses to dynamic exercise in males with high-normal blood pressure

While postexercise hypotension is associated with histamine H₁ and H₂ receptor-mediated postexercise vasodilation, effects of histaminergic vasodilation on blood pressure (BP) in response to dynamic exercise are not known. Thus, in 20 recreationally active male participants (10 normotensive and 10 with high-normal BP) we examined the effects of histamine H₁ and H₂ receptor blockade on cardiac output (CO), mean atrial pressure (MAP), aortic stiffness (AoStiff), and total vascular conductance (TVC) at rest and during progressive cycling exercise. Compared with the normotensive group, MAP, CO, and AoStiff were higher in the high-normal group before and after the blockade at rest, while TVC was similar. At the 40% workload, the blockade significantly increased MAP in both groups, while no difference was found in the TVC. CO was higher in the high-normal group than the normotensive group in both conditions. At the 60% workload, the blockade substantially increased MAP and decreased TVC in the normotensive group, while there were no changes in the high-normal group. A similar CO response pattern was observed at the 60% workload. These findings suggest that the mechanism eliciting an exaggerated BP response to exercise in the high-normal group may be partially due to the inability of histamine receptors. Novelty Males with high-normal BP had an exaggerated BP response to exercise. The overactive BP response is known due to an increase in peripheral vasoconstriction. Increase in peripheral vasoconstriction is partially due to inability of histamine receptors.

P4641Are coronary artery abnormalities in Kawasaki disease associated with iron deficiency anemia?

Purpose

Coronary artery abnormalities (CAA) are the most important complication of Kawasaki disease (KD). Iron deficiency anemia (IDA) is prevalent micronutrient deficiencies and its association with KD remains unknown. We hypothesized the presence of IDA could be a predictor of CAA.

Methods

This retrospective study included 173 KD patients, divided into two groups by absence (Group 1) and presence (Group 2) of CAA. The odds ratio (OR) with 95% confidence interval (CI) was calculated using a logistic regression model to estimate the association between CAA and other indicators. Due to the collinearity between the IDA indicators, each indicator was paired with anemia in 3 models.

Results

The 3 indicators of IDA, serum iron, iron saturation and ferritin, were all significantly higher in Group 1 than in Group 2. Three sets of models including anemia with iron indicators produced the odd ratio (OR) of CAA of 3.513, 3.171, and 2.256, respectively. The 3 indicators of IDA were negatively associated with CAA, by OR of 0.965, 0.914, and 0.944, respectively. The Area under the curve (AUC) of ferritin, iron saturation, serum iron, anemia, and Kobayashi score was 0.907 (95% CI, 0.851–0.963), 0.729 (95% CI, 0.648–0.810), 0.711 (95% CI, 0.629–0.793), 0.638 (95% CI, 0.545–0.731), and 0.563 (95% CI, 0.489–0.636) respectively.

Figure 1 & 3

Conclusion

The indicators of IDA, especially ferritin, were highly associated with CAA, so that they were stronger predictors compared to the Kobayashi score. The IDA indicators can be used to predict CAA development and suggest the need for early intervention.

Acknowledgement/Funding

None

P5661Validation of CHA2DS2-VA score (excluding female sex) in non-valvular atrial fibrillation patients: a nationwide population-based study

Background

Sex category (Sc, ie, female sex) confers 1 point on CHA2DS2-VASc score. So, no woman with atrial fibrillation (AF) can have a CHA2DS2-VASc score of 0. This study aimed to compare CHA2DS2-VA (excluding female sex) and CHA2DS2-VASc score in Korean AF patients.

Methods

Using the Korean National Health Insurance Service database, we analyzed the risk of ischemic stroke in non-valvular AF patients between 2013 and 2017. The predictive value of the CHA2DS2-VA and CHA2DS2-VASc scores for ischemic stroke was evaluated by c-statistic difference and net reclassification improvement (NRI). The propensity score matching method was used to balance covariates across male and female AF patients.

Results

A total of 182,133 patients with AF (49.2% women) were included to this study. The adjusted incidence rate (IR) of ischemic stroke was not significantly different between males and females (0.89%/y and 0.90%/y, respectively, p=0.411) in low-risk patients without risk factor. Also, no sex difference was found in high-risk patients with above 2 risk factors for ischemic stroke (4.46%/y for male and 4.49%/y for male, p=0.498). In c-statistic analysis for ischemic stroke, there was no significant difference between the CHA2DS2-VA and CHA2DS2-VASc scores (AUC 0.662 vs. 0.664, z=1.572, p=0.116). When compared with CHA2DS2-VASc score, CHA2DS2-VA score was not significantly inferior in net reclassification improvement (NRI 0.031, 95% CI 0.002–0.037, p=0.118) for ischemic stroke.

C-statistics

Conclusions

In Korean AF patients, the CHA2DS2-VA score excluding female sex is a useful risk scoring system for ischemic stroke.

Within-cluster resampling for multilevel models under informative cluster size

A within-cluster resampling method is proposed for fitting a multilevel model in the presence of informative cluster size. Our method is based on the idea of removing the information in the cluster sizes by drawing bootstrap samples which contain a fixed number of observations from each cluster. We then estimate the parameters by maximizing an average, over the bootstrap samples, of a suitable composite loglikelihood. The consistency of the proposed estimator is shown and does not require that the correct model for cluster size is specified. We give an estimator of the covariance matrix of the proposed estimator, and a test for the noninformativeness of the cluster sizes. A simulation study shows, as in Neuhaus & McCulloch (2011), that the standard maximum likelihood estimator exhibits little bias for some regression coefficients. However, for those parameters which exhibit nonnegligible bias, the proposed method is successful in correcting for this bias.

The use of postoperative prophylactic antibiotics in stented distal hypospadias repair: a systematic review and meta-analysis

INTRODUCTION

The current literature on the use of antibiotics perioperatively for many pediatric procedures, including hypospadias, is inconsistent. There is currently no clear evidence for the use of postoperative antibiotic prophylaxis for stented distal hypospadias repair.

OBJECTIVE

This study aims to synthesize and assess the available literature on the use versus non-use of postoperative antibiotic prophylaxis for stented distal hypospadias repair.

METHODOLOGY

Systematic literature search was performed on March 2018 for evaluation of trials that assessed the use and non-use of postoperative prophylactic antibiotics among stented distal hypospadias repair in children. Methodological quality of the studies was assessed according to the study design as recommended by the Cochrane Collaboration. The outcome assessed includes composite overall posthypospadias repair complications of infection and wound healing complications. The event rate for each treatment group was extracted to extrapolate intervention relative risk (RR) and corresponding 95% confidence interval (CI). Mantel-Haenszel method with random effect model was used in pooling of effect estimates from the included studies. Heterogeneity was assessed with subgroup analysis performed according to the study design. Publication bias was likewise determined. The protocol of this review was registered in PROSPERO (CRD42018087301) and reported in accordance with preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines.

RESULT

A total of seven studies (four cohorts, three randomized controlled trials) with 986 stented distal hypospadias repairs (408 with no post-operative prophylactic antibiotics and 578 given postoperative prophylactic antibiotics) were included for the meta-analysis. Moderate to serious risk of bias was noted among the cohort studies, while the included randomized controlled trials (RCT) were of high risk of bias. Inconsistencies of effect estimates between subgroups and publication bias with small study effect were likely present. The overall pooled effect estimates comparing treatment groups showed no significant difference for outcomes of overall composite postoperative complication (RR 0.93, 95% CI 0.45, 1.93). Assessment of composite infection related complications and wound healing complications likewise did not show any significant between-group differences (RR 1.28, 95% CI 0.49, 3.35 and RR 1.01, 95% CI 0.48, 2.12; respectively) (Table). Asymptomatic bacteriuria was noted to be significantly higher among the intervention group with no postoperative prophylactic antibiotics (RR 4.01, 95% CI 1.11, 14.54).

CONCLUSION

The available evidence to date was assessed to be of high risk. The low level of evidence generated suggests that there is limited utility in the use of postoperative prophylactic antibiotics to prevent clinically significant posthypospadias repair complications.

The evaluation of vesicoureteral reflux among children using contrast-enhanced ultrasound: a literature review

INTRODUCTION

Voiding cystourethrogram (VCUG) with fluoroscopy remains the gold standard for detection and evaluation of vesicoureteral reflux (VUR) among children. However, the ionizing radiation exposure remains a concern for this diagnostic modality. Recent studies have proposed using contrast-enhanced ultrasound as an alternative option for VUR screening and follow-up in children. The aim of the study was to review the literature of comparative studies that assessed the diagnostic accuracy of contrast-enhanced ultrasound compared with VCUG.

METHODOLOGY

A systematic literature search was performed on electronic medical literature databases in July 2017. Literature identification, screening, and assessment of eligibility were performed by five reviewers with a pediatric radiologist. Literature was summarized for the study population, contrast used, and ultrasound mode as well as the timing of comparative reference study being performed. The studies were clustered according to the kind of contrast used. Reported diagnostic accuracy was extracted from individual studies and summarized across the included studies using descriptive statistics of median and interquartile range (IQR).

RESULT

A total of 45 comparative studies were identified as eligible for the summary of the literature. Two generations of ultrasound contrast were identified in the available studies (first generation, Levovist and second generation, SonoVue). For the ultrasound studies using the first-generation contrast, the median sensitivity, regardless of the ultrasound mode, was 90.25 (IQR 83.25-97), and the median specificity was 93 (IQR 91.3-95.25). Among studies using the second-generation contrast, the median sensitivity was 86.26 (IQR 81.13-97), and the median specificity was 90.99 (IQR 84-98). No serious adverse events were reported in any of the studies.

CONCLUSION

Overall, this review highlights the application of contrast-enhanced ultrasound for its advantage of no exposure to ionizing radiation and diagnostic accuracy relatively comparable to VCUG in the evaluation of VUR. In addition to the functional evaluation of the VUR, it also provides an anatomic evaluation of the kidneys and bladder with ultrasound imaging. However, one should also note that this alternate procedure is highly operator dependent where diagnostic accuracy is excellent when the expertise is available.

Functional MRI as an Objective Measure of Olfaction Deficit in Patients with Traumatic Anosmia

BACKGROUND AND PURPOSE

While posttraumatic anosmia is not uncommon, the olfactory function evaluation has strongly relied on subjective responses given by patients. We aimed to examine the utility of fMRI as an objective tool for diagnosing traumatic anosmia.

MATERIALS AND METHODS

Sixteen patients (11 men and 5 women; mean age, 42.2 ± 10.4 years) with clinically diagnosed traumatic anosmia and 19 healthy control subjects (11 men and 8 women; mean age, 29.3 ± 8.5 years) underwent fMRI during olfactory stimulation with citral (a pleasant odor) or β-mercaptoethanol (an unpleasant odor). All patients were subjected to a clinical olfactory functional assessment and nasal endoscopic exploration. Two-sample t tests were conducted with age as a covariate to examine group differences in brain activation responses to olfactory stimulation (false discovery rate-corrected P < .05).

RESULTS

Compared with healthy control subjects, patients with traumatic anosmia had reduced activation in the bilateral primary and secondary olfactory cortices and the limbic system in response to β-mercaptoethanol stimulation, whereas reduced activation was observed only in the left frontal subgyral region in response to citral stimulation.

CONCLUSIONS

Brain activation was decreased in the bilateral primary and secondary olfactory cortices as well as the limbic system in response to olfactory stimulation in patients with traumatic anosmia compared with healthy control subjects. These preliminary results may shed light on the potential of fMRI for the diagnosis of traumatic anosmia.

Salivary gland ultrasonography findings are associated with clinical, histological, and serologic features of Sjögren's syndrome

OBJECTIVE

Salivary gland ultrasonography (SGUS) has been applied in the diagnosis of Sjögren's syndrome (SS). The aim of this study is to investigate the association of SGUS findings with clinical, histological, and serologic features of SS.

METHODS

A total of 104 patients with suspected SS underwent SGUS for evaluation of salivary gland involvement. Patients with primary SS were determined according to the classification criteria for SS. The parenchymal inhomogeneity of bilateral parotid and submandibular glands was graded from 0 (homogeneity) to 4 (gross inhomogeneity). Receiver operating characteristic curve analysis was performed to compare the diagnostic performance of different SGUS scoring methods. Clinical and serologic features were compared between groups classified by SGUS score. The association between SGUS and these features of SS was explored by multivariable linear regression analysis.

RESULTS

Study participants were predominantly women (96.2%) and had a mean age of 54.1 years. Eighty-seven patients and 88 patients with primary SS were identified based on AECG criteria and ACR/EULAR classification criteria for SS, respectively. Among the different scoring methods, the sum of the grades of four salivary glands (range 0-16) had the best diagnostic performance, with sensitivity of 77.3% and specificity of 87.5% (cutoff value, 7) for distinguishing primary SS from sicca non-SS. SGUS score was associated with focus score in labial salivary gland biopsy (β = 0.240, p = 0.033) and anti-Ro/SSA serology (β = 0.283, p = 0.016) and inversely associated with unstimulated whole salivary flow (β = -0.298, p = 0.011).

CONCLUSION

Ultrasonography of major salivary glands is associated with histopathology of minor salivary glands, serology of SS, and salivary gland function.

Corticocancellous bone graft vs cancellous bone graft for the management of unstable scaphoid nonunion

INTRODUCTION

This study was undertaken to determine whether corticocancellous bone grafting and cancellous bone grafting differ in terms of bone union rate, restoration of scaphoid anatomy, and wrist function when unstable scaphoid nonunions are concomitantly treated by screw fixation.

MATERIALS AND METHODS

This is retrospective cohort study. In Group A (17 patients), unstable scaphoid nonunion was treated with corticocancellous graft harvested from the iliac crest and headless compression screw using volar approach. In Group B (18 patients), unstable scaphoid nonunion was treated with cancellous graft harvested from the distal radius or iliac crest and headless compression screw using volar approach Mean time to union was measured using CT image. Scaphoid deformity was also measured using lateral intrascaphoid angle and height to length ratio using CT images. Wrist functional status was assessed by measuring grip strength, wrist range of motion, and DASH score at 1 year postoperatively.

RESULTS

Mean time to union was significantly greater in Group A (15 weeks vs. 11 weeks). No significant intergroup difference was observed for lateral intrascaphoid angle and height to length ratio after treatment of scaphoid nonunion. No significant intergroup difference was observed for grip strength, wrist range of motion, or DASH scores at 1 year postoperatively.

CONCLUSIONS

Cancellous bone grafting was found to lead to earlier bone union than corticocancellous bone grafting and to similar restorations of scaphoid deformity and wrist function when scaphoid nonunion was treated by headless compression screw fixation and bone grafting.

LEVEL OF EVIDENCE

Prognostic, III.

Bovine colostrum supplementation does not affect plasma I-FABP concentrations following exercise in a hot and humid environment

PURPOSE

To quantify the impact of a 14-day bovine colostrum (BC) supplementation on intestinal cell damage following exercise in a hot and humid environment.

METHODS

Ten male participants (20 ± 2 years, VO_2max 55.80 ± 3.79 mL kg^-1 min^-1, 11.81 ± 2.71% body fat) ran for 46 ± 7.75 min at 95% of ventiliatory threshold in 40 °C and 50% RH following a 14-day double-blinded supplementation with either BC or placebo (Plac). Core temperature, skin temperature, heart rate, and rating of perceived exertion were recorded every 5 min during exercise. Blood was taken pre, post, 1 h, and 4 h post exercise. Intestinal cell damage was assessed via intestinal fatty acid binding protein (I-FABP).

RESULTS

I-FABP concentrations were similar between conditions at all time points [pre 989.39 ± 490.88 pg ml^-1 (BC) 851.35 ± 450.71 pg ml^-1 (Plac) post 1505.10 ± 788.63 pg ml^-1 (BC) 1267.12 ± 521.51 pg ml^-1 (Plac) 1-h, 1087.77 ± 397.06 pg ml^-1 (BC) 997.25 ± 524.74 pg ml^-1 (Plac) 4-h, 511.35 ± 243.10 pg ml^-1 (BC) 501.46 ± 222.54 pg ml^-1 (Plac)]. I-FABP was elevated pre to post exercise for both BC (162 ± 50%) and Plac (162 ± 56%) (p < 0.05). BC had no effect on mean body temperature [beginning 36.11 ± 0.30 °C, ending: 39.52 ± 0.28 °C (BC); beginning:35.96 ± 0.43 °C, ending:39.42 ± 0.38 °C (Plac)].

CONCLUSIONS

While BC supplementation may protect against enterocyte damage during exercise in thermonuetral environments, our data suggest that BC supplementation may not be an effective technique for preventing enterocyte damage during exercise when core temperature exceeds 39 °C.

Intra-articular comminution worsens outcomes of distal radial fractures treated by open reduction and palmar locking plate fixation

We studied 50 patients with AO type C2 distal radial fractures and 35 with AO type C3 distal radial fractures treated by open reduction and palmar locking plate fixation. At 3-month clinical assessments, mean wrist flexion arcs, grip strengths and disabilities of the arm, shoulder and hand scores were significantly better for AO type C2 fractures. At 2-year post-operative clinical assessments, mean disabilities of the arm, shoulder and hand scores were significantly better for AO type C2 fractures than for AO type C3 fractures. At 2-year radiographic examinations, anterior angulations, ulnar variances and arthritis grades were also significantly better for AO type C2 fractures. This study showed that AO type C3 distal radial fractures, which have intra-articular comminution, had poorer clinical and radiographic outcomes than AO type C2 fractures, despite open reduction and palmar locking plate fixation.

LEVEL OF EVIDENCE

IV.

Natural history and factors associated with ulnar-sided wrist pain in distal radial fractures treated by plate fixation

We documented longitudinal changes in the incidence of ulnar-sided wrist pain after distal radial fractures treated by plate fixation and identified factors associated with ulnar-sided wrist pain. A total of 140 patients were enrolled in this study. Radiographs were taken 3 months after operation, and were used to measure radial inclination, anterior angulation and ulnar variance, and to identify the presence of an ulnar styloid fracture. Clinical assessments at the same time included grip strengths, ranges of wrist motion and the patient-rated wrist evaluation questionnaire. The presence of ulnar-sided wrist pain was noted at each follow-up visit. The incidence of ulnar-sided wrist pain decreased significantly with time after surgery (22 patients at 3 months, 11 patients at 6 months and three patients at 12 months). The mean age, sex, the presence of an ulnar styloid fracture and the classification of the distal radial fracture were not factors that were associated with a higher incidence of ulnar-sided wrist pain, but there was an association between higher patient-rated wrist evaluation scores and the presence of ulnar-sided wrist pain.

LEVEL OF EVIDENCE

Prognosis, Level IV.

Characterization of microRNAs and their target genes associated with transcriptomic changes in gamma-irradiated Arabidopsis

MicroRNAs (miRNAs) regulate gene expression in response to biotic and abiotic stress in plants. We investigated gamma-ray-responsive miRNAs in Arabidopsis wild-type and cmt3-11t mutant plants using miRNA microarray analysis. miRNA expression was differentiated between the wild-type and cmt3-11t mutants. miR164a, miR169d, miR169h, miR172b*, and miR403 were identified as repressible in the wild-type and/or cmt3-11t mutant in response to gamma irradiation, while miR827, miR840, and miR850 were strongly inducible. These eight miRNA genes contain UV-B-responsive cis-elements, including G-box, I-box core, ARE, and/or MBS in the putative promoter regions. Moreover, Box 4, MBS, TCA-element, and Unnamed_4, as well as CAAT- and TATA-box, were identified in these eight miRNA genes. However, a positive correlation between the transcriptions of miRNAs and their putative target genes was only observed between miR169d and At1g30560 in the wild-type, and between miR827 and At1g70700 in the cmt3-11t mutant. Quantitative RT-PCR analysis confirmed that the transcription of miR164a, miR169d, miR169h, miR172b*, miR403, and miR827 differed after gamma irradiation depending on the genotype (wild-type, cmt3-11t, drm2, drd1-6, and ddm1-2) and developmental stage (14 or 28 days after sowing). In contrast, high transcriptional induction of miR840 and miR850 was observed in these six genotypes regardless of the developmental stage. Although the actual target genes and functions of miR840 and miR850 remain to be determined, our results indicate that these two miRNAs may be strongly induced and reproducible genetic markers in Arabidopsis plants exposed to gamma rays.

Histamine H2 receptor blockade augments blood pressure responses to acute submaximal exercise in males

Histamine is a potent vasodilator that has been found to increase during exercise. We tested the hypothesis that histamine would attenuate blood pressure (BP), cardiac output (CO), and vascular resistance responses to short-term, submaximal dynamic exercise during H2 receptor blockade. Fourteen healthy men (20-29 years of age) were studied. Systolic (SBP), diastolic (DBP), and mean arterial (MAP) BP and heart rate (HR) were assessed at rest and during the last minute of 10 min of submaximal cycling exercise (60% of peak oxygen consumption) in the absence and presence of histamine H2 receptor blockade (ranitidine, 300 mg). Stroke volume (SV) (impedance cardiography) and plasma norepinephrine (NE) were measured, and CO, rate × pressure product (RPP), and total peripheral resistance (TPR) were calculated. Plasma levels of histamine were also measured. H2 blockade had no effects on any variables at rest. During exercise, SBP (184 ± 3 mm Hg vs. 166 ± 2 mm Hg), MAP (121 ± 2 mm Hg vs. 112 ± 5 mm Hg), and RPP (25.9 ± 0.8 × 10(3) mm Hg·beats/min vs. 23.5 ± 0.8 × 10(3) mm Hg/beats·min) were greater during blocked conditions (P < 0.05), and an interaction was observed for TPR. SV, DBP, HR, and NE levels were unaffected by blockade. Plasma histamine increased from 1.83 ± 0.14 ng/mL at rest to 2.33 ± 0.23 ng/mL during exercise (P < 0.05) and was not affected by H2 blockade (1.56 ± 0.23 ng/mL vs. 1.70 ± 0.24 ng/mL). These findings suggest that, during submaximal exercise, histamine attenuates BP, vascular resistance, and the work of the heart via activation of H2 receptors and that these effects occurred primarily in the vasculature and not in the myocardium.

Effects of supplemental lysine and methionine with zilpaterol hydrochloride on feedlot performance, carcass merit, and skeletal muscle fiber characteristics in finishing feedlot cattle

Feeding zilpaterol hydrochloride (ZH) with ruminally protected AA was evaluated in a small-pen feeding trial. Crossbred steers ( = 180; initial BW = 366 kg) were blocked by weight and then randomly assigned to treatments (45 pens; 9 pens/treatment). Treatment groups consisted of no ZH and no AA (Cont-), ZH and no AA (Cont+), ZH and a ruminally protected lysine supplement (Lys), ZH and a ruminally protected methionine supplement (Met), and ZH and ruminally protected lysine and methionine (Lys+Met). Zilpaterol hydrochloride (8.3 mg/kg DM) was fed for the last 20 d of the finishing period with a 3-d withdrawal period. Lysine and Met were top dressed daily for the 134-d feeding trial to provide 12 or 4 g·hd·d, respectively, to the small intestine. Carcass characteristics, striploins, and prerigor muscle samples were collected following harvest at a commercial facility. Steaks from each steer were aged for 7, 14, 21, and 28 d, and Warner-Bratzler shear force (WBSF) was determined as an indicator of tenderness. Prerigor muscle samples were used for immunohistological analysis. Cattle treated with Met and Lys+Met had increased final BW ( < 0.3) and ADG ( < 0.05) compared to Cont- and Cont+. Supplementation of Lys, Met, and Lys+Met improved G:F ( < 0.05) compared to Cont- during the ZH feeding period (d 111 to 134) as well as the entire feeding period ( < 0.05). Zilpaterol hydrochloride increased carcass ADG ( < 0.05) when compared to non-ZH-fed steers. Methionine and Lys+Met treatments had heavier HCW ( < 0.02) than that of Cont-. Yield grade was decreased ( < 0.04) for Cont+ steers compared to steers treated with Lys, Lys+Met, and Cont-. Tenderness was reduced ( < 0.05) with ZH regardless of AA supplementation. Lysine, Met, Lys+Met, and Cont+ had less tender steaks ( < 0.05) throughout all aging groups compared to Cont-. Steaks from Lys-treated steers were less tender ( < 0.05) than those of Cont+ during the 7- and 14-d aging periods. Nuclei density was the greatest with Cont- cattle compared to all other treatments suggesting a dilution effect of the nuclei in the larger muscle fibers with ZH feeding. Supplementation of Met in conjunction with ZH feeding increased ADG and HCW although this may lead to decreased tenderness even after aging for 28 d. These findings indicated that steers fed ZH may require additional AA absorbed from the small intestine to maximize performance.