Collagen V haploinsufficiency in female murine patellar tendons results in altered matrix engagement and cellular density, demonstrating decreased healing.

Collagen V (Col5) is a quantitatively minor component of collagen fibrils comprising tendon, however, plays a crucial role in regulation of development and dynamic healing processes. Clinically, patients with COL5a1 haploinsufficiency, known as classic Ehlers-Danlos Syndrome (cEDS), present with hyperextensible skin, joint instability and laxity, with females more likely to be affected. Previous studies in Col5-deficient mice indicated that reduced Col5a1 expression leads to a reduction in stiffness, fibril deposition, and altered fibril structure. Additionally, Col5-deficient male tendons demonstrated altered healing compared to wild-type tendons, however female mice have not yet been studied utilizing this model. Along with clinical differences between sexes in cEDS patient populations, differences in hormone physiology may be a factor influencing tendon health. Therefore, the objective of this study was to utilize a Col5a1+/ - female mouse model, to determine the effect of Col5 on tendon cell morphology, cell density, tissue composition, and mechanical properties throughout healing. We hypothesized that reduction in Col5 expression would result in an abnormal wound matrix post-injury, resulting in reduced mechanical properties compared to normal tendons. Following patellar tendon surgery, mice were euthanized at 1, 3, and 6-week post-injury. Col5-deficient tendons demonstrated altered and decreased healing compared to WT tendons. The lack of resolution in cellularity by 6-week post-injury in Col5-deficient tendons influenced the decreased mechanical properties. Stiffness did not increase post-injury in Col5-deficient mice, and collagen fiber realignment was delayed during mechanical loading. Therefore, increased Col5a1 expression post-injury is necessary to re-establish matrix engagement and cellularity throughout tendon healing.

Presumed Melanocytoma-Associated Choroidal Neovascular Membrane with Hemorrhage Successfully Treated with Intravitreal Aflibercept Injections.

A patient presented with melanocytoma and associated choroidal neovascular membrane with hemorrhage involving the macula. The patient was treated with monthly aflibercept (Eylea) injections with significant improvement of best corrected visual acuity. In this report, we explore the development of a choroidal neovascular membrane (CNVM) formation in a patient with melanocytoma and the effect of intravitreal aflibercept (Eylea) on disease course. Case report study used patient data obtained from examination and imaging. The patient was treated with monthly intravitreal aflibercept injections leading to complete resolution of CNVM and hemorrhage, with significant improvement of best corrected visual acuity. Awareness and proper monitoring for the sequelae of melanocytoma are important for early detection and prevention of visually threatening outcomes. In cases of melanocytoma-associated CNVM formation with large subretinal hemorrhage, intravitreal aflibercept can be an effective tool for inducing CNVM regression and allowing improvement of visual acuity.

Multicenter analysis of stereotactic radiosurgery for multiple brain metastases from EGFR and ALK driven non-small cell lung cancer.

INTRODUCTION: Patients with brain metastases (BrMs) arising from EGFR and ALK driven non-small cell lung cancer (NSCLC) have favorable prognoses and evolving treatment options. We evaluated multicenter outcomes for stereotactic radiosurgery (SRS) to multiple (≥4) BrMs, where randomized data remain limited. METHODS: Data were collected retrospectively from 5 academic centers on EGFR and ALK NSCLC who received SRS to ≥4 BrMs with their first SRS treatment between 2008 and 2018. Analyzed endpoints included overall survival (OS), freedom from CNS progression (FFCNSP), and freedom from whole-brain radiotherapy (FFWBRT). RESULTS: Eighty-nine patients (50 EGFR, 39 ALK) received a total of 159 SRS treatments to 1,080 BrMs, with a median follow up of 51.3 months. The median number of BrMs treated with SRS treatment-1 was 6 (range 4-26) and median for all treatments was 9 (range 4-47). Sixteen patients (18 %) had received WBRT prior to SRS treatment-1. The median OS was 24.2, 21.2, and 33.2 months for all patients, EGFR, and ALK subsets, respectively. After multivariable adjustment, only receipt of a next-generation tyrosine kinase inhibitor was associated with OS (HR 0.40, p = 0.005). No differences in OS were observed based on number of BrMs treated. The median FFCNSP was 9.4, 11.6, and 7.5 months, for all patients, EGFR, and ALK subsets, respectively. After multivariable adjustment, the number of BrMs (continuous) treated during treatment-1 was the only negative prognostic factor associated with FFCNSP (HR 1.071, p = 0.045). The 5-year FFWBRT was 73.6 %. CONCLUSIONS: This multicenter analysis over a >10-year period demonstrated favorable OS, FFCNSP, and FFWBRT, in patients with EGFR and ALK driven NSCLC receiving SRS to ≥4 BrMs. These data support SRS as an option in the upfront and salvage setting for higher burden CNS disease in this population.

NCCN Guidelines® Insights: Central Nervous System Cancers, Version 2.2022.

The NCCN Guidelines for Central Nervous System (CNS) Cancers focus on management of the following adult CNS cancers: glioma (WHO grade 1, WHO grade 2-3 oligodendroglioma [1p19q codeleted, IDH-mutant], WHO grade 2-4 IDH-mutant astrocytoma, WHO grade 4 glioblastoma), intracranial and spinal ependymomas, medulloblastoma, limited and extensive brain metastases, leptomeningeal metastases, non-AIDS-related primary CNS lymphomas, metastatic spine tumors, meningiomas, and primary spinal cord tumors. The information contained in the algorithms and principles of management sections in the NCCN Guidelines for CNS Cancers are designed to help clinicians navigate through the complex management of patients with CNS tumors. Several important principles guide surgical management and treatment with radiotherapy and systemic therapy for adults with brain tumors. The NCCN CNS Cancers Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights summarize the panel's most recent recommendations regarding molecular profiling of gliomas.

Post-injury tendon mechanics are not affected by tamoxifen treatment.

PURPOSE: A growing interest in the mechanisms that govern tendon healing has resulted in the develop-ment of tools, such as the tamoxifen-inducible mouse knockdown model, to address these questions. However, tamoxifen is a selective estrogen receptor modulator and may interfere with the tendon healing process. The objective of this study was to evaluate the effects of tamoxifen on post-injury tendon mechanics in wild-type mice. METHODS: The mice underwent treatment at the time of injury using an established mouse injury model and the injured tendons were evaluated 3 weeks post-injury. The treatment contained tamoxifen suspended in corn oil and was compared to a treatment with only corn oil, as well as mice with no treatment. Tendons were evaluated by measuring the quasi-static and viscoelastic mechanics, collagen fiber realignment, cellularity, and nuclear morphology. RESULTS: Mechanical testing of the tendons post-injury revealed no changes to viscoelastic mechanics, quasi-static mechanics, or collagen realignment during loading after tamoxifen treatment with the dosage regimen utilized (three daily injections of 4.5 mg/40 g body weight). Additionally, histological analysis revealed no changes to cellularity or cell nuclear shape. CONCLUSION: Overall, this study revealed that tamoxifen treatment at the time of tendon injury did not result in changes to tendon mechanics or the histological parameters at 3 weeks post-injury.

Factors Associated with Reconstruction Failure and Major Complications After Postmastectomy Radiation to a Reconstructed Breast.

PURPOSE: Postmastectomy radiation therapy is known to increase risk of complications in the reconstruction setting. We aim to identify the variables associated with reconstruction failure and other major complications. METHODS AND MATERIALS: A prospectively collected institutional database was queried for patients with up to stage IIIC breast cancer treated from 2000 to 2017, undergoing mastectomy, immediate implant or autologous tissue reconstruction, and radiation to the reconstructed breast within 1 year of surgery. Reconstruction failure was defined as complication requiring surgical revision or implant removal. Additional major complications were defined as any infection, contracture, necrosis, or fibrosis. Covariates of interest included age, body mass index, smoking status, stage, hormone receptor and HER2 status, systemic therapy timing, radiation technique, nodal irradiation, and interval between surgery and start of postmastectomy radiation therapy. Differences in complication rates were assessed with χ² or Fisher exact tests. Competing risk regression was used to estimate hazard ratios; covariates were included one at a time to avoid over adjustment. RESULTS: A total of 206 reconstructed breasts in 202 patients resulted from our initial query, with 139 treated with intensity-modulated radiation therapy (IMRT) and 67 treated with conventional radiation therapy (CRT). Median follow-up was 45 months (range, 4-210 months); patient cohorts were generally similar. Eight patients were excluded from toxicity analysis for insufficient follow-up (<2 years). Overall, reconstruction failure and major complication rates were significantly lower in the IMRT group. Reconstruction failure rates were 3.0% for IMRT versus 16.4% for CRT (P = .002), and major complication rates were 6.8% for IMRT versus 24.6% for CRT (P < .001). On univariate analysis, CRT was significantly predictive of implant failure (hazard ratio, 5.54; P = .003) and increased complication rates (hazard ratio, 3.83; P = .001). Significance persisted on multivariable analysis. Survival outcomes were similar, with no difference in 2 year overall survival (P = .12) and local recurrence (P = .41). CONCLUSIONS: Using IMRT may improve reconstruction outcomes over CRT, with significantly lower reconstruction failure and complication rates without compromising local control or survival.

Protecting Infants from Sudden Unexpected Infant Death: Guidelines for Interventions during the Perinatal Period from the French National College of Midwives.

With 300-400 annual deaths in France, sudden unexpected infant death (SUID) is the leading cause of mortality in France among infants from the end of their first through their 12th month of life. These clinical practice guidelines aim to identify strategies for (future) parents to prevent avoidable SUIDs. They are based on a narrative literature review and an analysis of the existing reports and guidelines available on the topic in 2019-2020. In summary, it is recommended that parents ensure that their infants sleep on their back on a firm, empty surface in a sufficiently ventilated environment, share the parental bedroom, and be breastfed and vaccinated. All of these actions create protective factors against SUID. Conversely, parents should know that several factors increase the risk of SUID: unsafe sleep, maternal smoking, passive smoking after birth, exposure to alcohol or other psychoactive substances, and excessive heat. Precis: Sudden Unexpected Infant Death prevention includes infants being breastfed and vaccinated, sleeping on their back, on a firm, empty surface, near parents, and that they are not overheated.

Decreased Clinical Toxicity and Two-Phase Elimination Kinetics Observed After Intravenous Iron Sucrose Overdose.

BACKGROUND: Management of oral iron overdoses is well-established, but there is limited literature regarding intravenous iron sucrose overdoses. Indications for administering deferoxamine after oral iron overdoses include clinical signs and symptoms of toxicity, along with a serum iron concentration ≥ 500 µg/dL. Reported signs and symptoms of iron sucrose overdose do not appear to correlate with those of oral iron overdoses. CASE REPORT: We present a case of intravenous iron sucrose overdose in a clinically well-appearing patient with a presenting serum iron concentration that was several times higher than the usual threshold concentration for initiating deferoxamine treatment. A 21-year-old woman presented to the emergency department after an accidental intravenous iron sucrose overdose. The patient received a home infusion of 1000 mg iron sucrose, which was five times the prescribed dose. Her presenting serum iron concentration was 1799 µg/dL, with bicarbonate and anion gap both within normal limits and an unremarkable physical examination. Because she did not have evidence of severe iron toxicity, she was treated supportively and deferoxamine was not administered. Her serum iron concentration decreased below the toxic range over the next 14 h, and she was discharged home the next day. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This patient was managed successfully with expectant care alone, suggesting that iron sucrose overdose has much lower toxicity than oral iron salt overdose. This discrepancy between measured iron concentrations and clinical presentation may be explained by the elimination kinetics of iron sucrose having separate redistribution and elimination phases.

Rates and types of urine drug screen false negative results compared with confirmatory toxicology testing in major trauma patients.

BACKGROUND: Trauma centers are required to screen patients for alcohol use, and if necessary, intervene and refer to treatment (SBIRT). Similar screening for illicit drug use is recommended but not required. Urine drug screening (UDS) underestimates problematic substance use. This study aimed to estimate the types and rates of UDS false negatives (FN) compared to comprehensive testing by liquid chromatography-mass spectrometry (LC-MS) in trauma patients. METHODS: We performed a prospective cohort study of deidentified urine samples from adult trauma and burn activation patients. Both UDS and LC-MS comprehensive testing of >200 analytes were performed by a reference laboratory on all samples. Iatrogenic medications were excluded from the FN count. Crosstab analyses were conducted for UDS versus LC-MS outcomes to establish FN types and rates. We dichotomized the results by creating an "intentionality" variable (intentional injuries by self/others versus accidental injuries). A series of crosstabs with odds ratios considered intentionality by substance class and demographics. Statistically significant variables by Chi-Square were assessed by logistic regression. RESULTS: Psychoactive FN were detected in 56/100 urine samples analyzed; the most frequent included anticonvulsants (primarily gabapentin, N = 13), opioid agonists (N = 12), antihistamines (primarily diphenhydramine, N = 10), and phenethylamines (primarily bupropion, N = 5). Nonpsychoactive FN were detected in 70/100 samples; the most common were nicotine (N = 33), caffeine (N = 23), acetaminophen (N = 22), and antidepressants (N = 12). Of substance classes included in the UDS and also tested by LC-MS, FN occurred for opiates (3%), amphetamines (5%) and opioids (25%). Polypharmacy was associated with fall injuries in elderly patients. Cocaine (p = 0.015) and cannabinoids (p = 0.002) were significantly associated with intentionality. CONCLUSIONS: Our results indicate that FN for potentially important psychoactive and nonpsychoactive substances are common when toxicologic testing is limited to routine UDS in trauma patients. We recommend expanding SBIRT in this patient population to include misuse of tobacco products, prescription analgesics, and over-the-counter antihistamines.

Real-world Use of Radiation for Newly Diagnosed Brain Metastases in Patients With ALK-positive Lung Cancer Receiving First-line ALK Inhibitor.

PURPOSE: Management paradigms now allow for systemic targeted drugs before central nervous system (CNS)-directed radiation therapy (RT) in selected asymptomatic patients with non-small cell lung cancer (NSCLC) and brain metastases (BM). We aimed to quantify how novel targeted agents with improved CNS activity, such as second-generation anaplastic lymphoma kinase (ALK) inhibitors (eg, alectinib), might affect the role of CNS-directed RT. METHODS AND MATERIALS: This retrospective, observational, real-world, patterns-of-care study used a nationwide, electronic, health record-derived, de-identified, longitudinal database. A random sample of patients with ALK+ advanced NSCLC and BM on first-line ALK-inhibitor monotherapy between January 1, 2014 and August 31, 2019 were included. Using an index date of the first instance of BM, the outcome was brain-directed local treatment within 4 months. Trends over time were reported and tested using multivariable modified Poisson regression with robust error variance, including an indicator during or after 2017 (when alectinib was approved). RESULTS: Of the 352 included patients, 146 had BM. In addition, 104 patients received CNS-directed local therapy, and 42 did not. The majority of patients (89.4%) were treated with RT alone. Of those receiving RT, stereotactic radiosurgery monotherapy was the most common (53%), followed by whole brain RT alone (39%). On multivariable analysis, patients who had their first BM during or after 2017 had a decreased rate of receiving local BM treatment versus those before 2017 with an adjusted incidence rate ratio of 0.63 (95% confidence interval [CI], 0.41-0.95; P = .026). We found no change in the proportion of BM treated with whole brain RT during or after 2017 versus before (adjusted incidence rate ratio: 0.70; 95% CI: 0.24-2.06; P = .517). CONCLUSIONS: We found decreasing use of CNS-directed RT in patients with NSCLC with new BM on first-line ALK inhibitors. Clinical outcomes for these patients require continued investigation, because physicians may become increasingly comfortable deferring upfront local therapy for BM in lieu of novel targeted agents with improved CNS activity.

Radiation Therapy for IDH-Mutant Grade 2 and Grade 3 Diffuse Glioma: An ASTRO Clinical Practice Guideline.

PURPOSE: This guideline provides evidence-based recommendations for adults with isocitrate dehydrogenase (IDH)-mutant grade 2 and grade 3 diffuse glioma, as classified in the 2021 World Health Organization (WHO) Classification of Tumours. It includes indications for radiation therapy (RT), advanced RT techniques, and clinical management of adverse effects. METHODS: The American Society for Radiation Oncology convened a multidisciplinary task force to address 4 key questions focused on the RT management of patients with IDH-mutant grade 2 and grade 3 diffuse glioma. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength. RESULTS: A strong recommendation for close surveillance alone was made for patients with oligodendroglioma, IDH-mutant, 1p/19q codeleted, WHO grade 2 after gross total resection without high-risk features. For oligodendroglioma, WHO grade 2 with any high-risk features, adjuvant RT was conditionally recommended. However, adjuvant RT was strongly recommended for oligodendroglioma, WHO grade 3. A conditional recommendation for close surveillance alone was made for astrocytoma, IDH-mutant, WHO grade 2 after gross total resection without high-risk features. Adjuvant RT was conditionally recommended for astrocytoma, WHO grade 2, with any high-risk features and strongly recommended for astrocytoma, WHO grade 3. Dose recommendations varied based on histology and grade. Given known adverse long-term effects of RT, consideration for advanced techniques such as intensity modulated radiation therapy/volumetric modulated arc therapy or proton therapy were given as strong and conditional recommendations, respectively. Finally, based on expert opinion, the guideline recommends assessment, surveillance, and management for toxicity management. CONCLUSIONS: Based on published data, the American Society for Radiation Oncology task force has proposed recommendations to inform the management of adults with IDH-mutant grade 2 and grade 3 diffuse glioma as defined by WHO 2021 classification, based on the highest quality published data, and best translated by our task force of subject matter experts.

Endophthalmitis Caused by Kocuria Kristinae.

Kocuria is an anaerobic, Gram-positive bacterium, which has been rarely reported to cause endophthalmitis following cataract surgery, intravitreal injections, penetrating ocular trauma, and also secondary to endogenous sources. Visual prognosis is often guarded, with no previous cases reporting a final visual acuity better than 20/60. We describe a young female patient who developed culture-proven Kocuria kristinae endophthalmitis associated with a traumatic scleral rupture. Visual acuity at 2 months of follow-up improved from light perception to 20/50 after treatment with intravitreal antimicrobial therapy and pars plana vitrectomy.

Increasing Vascular Response to Injury Improves Tendon Early Healing Outcome in Aged Rats.

Tendon injuries positively correlate with patient age, as aging has significant effects on tendon homeostatic maintenance and healing potential after injury. Vascularity is also influenced by age, with both clinical and animal studies demonstrating reduced blood flow in aged tissues. However, it is unknown how aging effects vascularity following tendon injury, and if this vascular response can be modulated through the delivery of angiogenic factors. Therefore, the objective of this study is to evaluate the vascular response following Achilles tendon injury in adult and aged rats, and to define the alterations to tendon healing in an aged model following injection of angiogenic factors. It was determined that aged rat Achilles tendons have a reduced angiogenesis following injury. Further, the delivery of vascular endothelial growth factor, VEGF, caused an increase in vascular response to tendon injury and improved mechanical outcome in this aged population. This work suggests that reduced angiogenic potential with aging may be contributing to impaired tendon healing response and that the delivery of angiogenic factors can rescue this impaired response. This study was also the first to relate changes in vascular response in an aged model using in vivo measures of blood perfusion to alterations in healing properties.

Prediction of Residual Curing Capacity of Melamine-Formaldehyde Resins at an Early Stage of Synthesis by In-Line FTIR Spectroscopy.

Melamine-formaldehyde (MF) resins are widely used as surface finishes for engineered wood-based panels in decorative laminates. Since no additional glue is applied in lamination, the overall residual curing capacity of MF resins is of great technological importance. Residual curing capacity is measured by differential scanning calorimetry (DSC) as the exothermic curing enthalpy integral of the liquid resin. After resin synthesis is completed, the resulting pre-polymer has a defined chemical structure with a corresponding residual curing capacity. Predicting the residual curing capacity of a resin batch already at an early stage during synthesis would enable corrective measures to be taken by making adjustments while synthesis is still in progress. Thereby, discarding faulty batches could be avoided. Here, by using a batch modelling approach, it is demonstrated how quantitative predictions of MF residual curing capacity can be derived from inline Fourier Transform infrared (FTIR) spectra recorded during resin synthesis using partial least squares regression. Not only is there a strong correlation (R2 = 0.89) between the infrared spectra measured at the end of MF resin synthesis and the residual curing capacity. The inline reaction spectra obtained already at the point of complete dissolution of melamine upon methylolation during the initial stage of resin synthesis are also well suited for predicting final curing performance of the resin. Based on these IR spectra, a valid regression model (R2 = 0.85) can be established using information obtained at a very early stage of MF resin synthesis.

Metastatic Melanoma With Leptomeningeal Disease.

Leptomeningeal disease in patients with melanoma historically portends a grim prognosis, with median survival measured in weeks to months. The advent of effective immunotherapy and targeted agents may modify the outcome of such patients. This case report describes a 43-year-old patient diagnosed with stage IIIa BRAF-positive cutaneous melanoma in 2012 who subsequently developed leptomeningeal involvement as her sole site of melanotic metastasis. She received multiple systemic therapies and radiotherapy and survived 2.5 years after her diagnosis with central nervous system involvement. This case report highlights the importance of a multidisciplinary team and the advent of effective agents, which offers the potential for significantly improved outcomes for patients with metastatic melanoma involving the central nervous system.

A unified multi-activation (UMA) model of cell survival curves over the entire dose range for calculating equivalent doses in stereotactic body radiation therapy (SBRT), high dose rate brachytherapy (HDRB), and stereotactic radiosurgery (SRS).

PURPOSE: Application of linear-quadratic (LQ) model to large fractional dose treatments is inconsistent with observed cell survival curves having a straight portion at high doses. We have proposed a unified multi-activation (UMA) model to fit cell survival curves over the entire dose range that allows us to calculate EQD2 for hypofractionated SBRT, SRT, SRS, and HDRB. METHODS: A unified formula of cell survival S = n / e D D o + n - 1 using only the extrapolation number of n and the dose slope of Do was derived. Coefficient of determination, R2 , relative residuals, r, and relative experimental errors, e, normalized to survival fraction at each dose point, were calculated to quantify the goodness in modeling of a survival curve. Analytical solutions for α and ß, the coefficients respectively describe the linear and quadratic parts of the survival curve, as well as the α/ß ratio for the LQ model and EQD2 at any fractional doses were derived for tumor cells undertaking any fractionated radiation therapy. RESULTS: Our proposed model fits survival curves of in-vivo and in-vitro tumor cells with R2  > 0.97 and r < e. The predicted α, ß, and α/ß ratio are significantly different from their values in the LQ model. Average EQD2 of 20-Gy SRS of glioblastomas and melanomas metastatic to the brain, 10-Gy × 5 SBRT of the lung cancer, and 7-Gy × 5 HDRB of endometrial and cervical carcinomas are 36.7 (24.3-48.5), 114.1 (86.6-173.1),, and 45.5 (35-52.6) Gy, different from the LQ model estimates of 50.0, 90.0, and 49.6 Gy, respectively. CONCLUSION: Our UMA model validated through many tumor cell lines can fit cell survival curves over the entire dose range within their experimental errors. The unified formula theoretically indicates a common mechanism of cell inactivation and can estimate EQD2 at all dose levels.

A Case Report of a Severe, Unusually Delayed Anaphylactoid Reaction to Intravenous N-Acetylcysteine During Treatment of Acute Acetaminophen Toxicity in an Adolescent.

INTRODUCTION: Anaphylactoid reactions are well-documented adverse events associated with the intravenous administration of N-acetylcysteine (NAC) in patients with acetaminophen overdose. Most reactions are mild, occurring within the first 1-5 hours of initiation. This report presents the case of an adolescent with a delayed, life-threatening anaphylactoid reaction 24.5 hours after starting NAC, where discontinuing NAC could have resulted in fulminant hepatic failure (FHF) and death. CASE REPORT: A 17-year-old previously healthy female presented with nausea, vomiting, and abdominal pain 10 hours after an acute acetaminophen ingestion. Her 11-hour serum acetaminophen concentration was above the treatment line (149 µg/mL), and she had elevated transaminases (AST = 202 U/L, ALT = 284 U/L). She was treated with intravenous NAC, which was suspended for 3 hours after she developed an apparent life-threatening anaphylactoid reaction with angioedema and respiratory distress 24.5 hours after treatment initiation. Given her high risk of progression to FHF, NAC was resumed at double the previous rate along with scheduled corticosteroids and antihistamines after resolution of her symptoms. Her AST increased to 10,927 U/L, and INR peaked at 3.6, but she had no further anaphylactoid symptoms. She was discharged in her normal state of health after 6 days. DISCUSSION: Discontinuing NAC in this case of severe, delayed anaphylactoid reaction could have resulted in FHF requiring liver transplant. The reason for her reaction is unclear but could be related to patient risk factors or medication error. Guidelines for reinitiation of NAC after development of delayed anaphylactoid reactions are not well-established.  Close observation beyond the first 1-5 hours of NAC administration is warranted.