Publications by authors named "Justine Chen"

3 Publications

  • Page 1 of 1

Dynamic Intracranial Pressure Waveform Morphology Predicts Ventriculitis.

Neurocrit Care 2021 Jul 30. Epub 2021 Jul 30.

Department of Neurology, Columbia University Vagelos College of Physicians and Surgeons, 177 Fort Washington Ave, 8 Milstein - 300 Center, New York, NY, USA.

Background: Intracranial pressure waveform morphology reflects compliance, which can be decreased by ventriculitis. We investigated whether morphologic analysis of intracranial pressure dynamics predicts the onset of ventriculitis.

Methods: Ventriculitis was defined as culture or Gram stain positive cerebrospinal fluid, warranting treatment. We developed a pipeline to automatically isolate segments of intracranial pressure waveforms from extraventricular catheters, extract dominant pulses, and obtain morphologically similar groupings. We used a previously validated clinician-supervised active learning paradigm to identify metaclusters of triphasic, single-peak, or artifactual peaks. Metacluster distributions were concatenated with temperature and routine blood laboratory values to create feature vectors. A L2-regularized logistic regression classifier was trained to distinguish patients with ventriculitis from matched controls, and the discriminative performance using area under receiver operating characteristic curve with bootstrapping cross-validation was reported.

Results: Fifty-eight patients were included for analysis. Twenty-seven patients with ventriculitis from two centers were identified. Thirty-one patients with catheters but without ventriculitis were selected as matched controls based on age, sex, and primary diagnosis. There were 1590 h of segmented data, including 396,130 dominant pulses in patients with ventriculitis and 557,435 pulses in patients without ventriculitis. There were significant differences in metacluster distribution comparing before culture-positivity versus during culture-positivity (p < 0.001) and after culture-positivity (p < 0.001). The classifier demonstrated good discrimination with median area under receiver operating characteristic 0.70 (interquartile range 0.55-0.80). There were 1.5 true alerts (ventriculitis detected) for every false alert.

Conclusions: Intracranial pressure waveform morphology analysis can classify ventriculitis without cerebrospinal fluid sampling.
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July 2021

A Case Report of Recombinant Tissue Plasminogen Activator Use in a SPAN-100-Positive Geriatric Patient with Thrombocytopenia.

Cureus 2017 Dec 11;9(12):e1933. Epub 2017 Dec 11.

Neurology, Columbia University.

Thrombocytopenia (platelet count: < 100,000/mm) is considered a contraindication in the use of intravenous thrombolysis for acute ischemic stroke. Little literature exists regarding tissue plasminogen activator (tPA) usage in thrombocytopenic patients, especially in older patients. Age and stroke severity are major prognostic indicators of the risk of hemorrhagic transformation. The Stroke Prognostication using Age and NIH Stroke Scale (SPAN) index estimates a patient's risk of intracerebral hemorrhage (ICH) and clinical response to thrombolysis by combining age in years with the National Institutes of Health Stroke Scale (NIHSS) scores. If the total numeric sum is 100 or more, these individuals are considered SPAN-100-positive, while those with a sum less than 100 are considered SPAN-100-negative patients. SPAN-100-positive patients are found to have a greater risk of ICH and poorer long-term outcomes than SPAN-100-negative patients both with and without thrombolysis treatment. SPAN-100-positive patients are found to have a greater risk of ICH and poorer long-term outcomes than SPAN-100-negative patients both with and without thrombolysis treatment. Nonetheless, SPAN-100-positive patients treated with tPA have a reduced relative likelihood of severe disability or death than SPAN-100-positive patients not treated with tPA. We report a case of a SPAN-100-positive, 90-year-old community-dwelling patient who presented with an acute ischemic stroke, an NIHSS score of 14 with near complete left-sided plegia, and a platelet count of 85,000/mm. Our patient was at increased risk of ICH and poor outcome regardless of tPA administration. However, due to the patient's high functional capacity prior to hospitalization and probable severe morbidity with poor recovery potential at his age, he was treated with tPA and showed a rapid improvement in neurological symptoms with no thrombolytic-associated morbidity. Thrombolytic therapy requires a case-by-case approach. Taking into account the patient's baseline and recovery potential is critical. Even absolute and relative contraindications, as they stand now, may need reconsideration, particularly those with little empiric evidence. More research is indicated to establish if thrombocytopenia should be reclassified as a relative rather than absolute contraindication to tPA.
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December 2017

Increased IL-21 secretion by aged CD4+T cells is associated with prolonged STAT-4 activation and CMV seropositivity.

Aging (Albany NY) 2012 Sep;4(9):648-59

Department of Medicine, Division of Basic and Clinical Immunology, University of California, Irvine, CA 92617, USA.

Advancing age leads to significant decline in immune functions. IL-21 is produced primarily by T follicular helper (Tfh) cells and is required for effective immune cell functions. Here we compared the induction of IL-21 in aged and young subjects. Our investigation demonstrates that CD4+T cells from healthy elderly individuals (age ≥ 65) secreted significantly higher levels of IL-21 on priming with aged and young dendritic cells (DC). Though the aged and young DCs secreted comparable levels of IL-12 on stimulation with anti-CD40 antibody and LPS, culture of DCs with aged CD4+ T cells resulted in increased production of IL-21 as compared to that with young CD4+ T cells. Further examination revealed that the response of aged naïve CD4+ T cells to IL-12 was altered, resulting in increased differentiation of aged Th cells towards Tfh cells. Investigation into the signaling mechanism suggested that phosphorylation of STAT-4 in response to IL-12 was sustained for a longer duration in aged CD4+ T cells as compared to CD4+ T cells from young subjects. Additional analysis demonstrated that increased IL-21 secretion correlated with chronic CMV infection in aged subjects. These findings indicate that chronic CMV infection alters the response of aged CD4+ T cells to IL-12 resulting in an increased secretion of IL-21 and that aging affects Tfh cell responses in humans which may contribute to age-associated inflammation and immune dysfunctions.
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September 2012