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Dive into the research topics where Howard T. Chang is active.

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Featured researches published by Howard T. Chang.


Archives of Pathology & Laboratory Medicine | 2004

Balamuthia mandrillaris Meningoencephalitis in an Immunocompetent Patient An Unusual Clinical Course and a Favorable Outcome

Sungmi Jung; Robert L. Schelper; Govinda S. Visvesvara; Howard T. Chang

Balamuthia mandrillaris meningoencephalitis is a rare but often fatal infection; only 2 survivors have been reported to date worldwide. We report the case of an apparently immunocompetent patient (72-year-old woman) who developed several episodes of seizures without prior history of respiratory or skin infections. Magnetic resonance imaging with contrast revealed 2 ring-enhancing lesions, one in the right precentral region and the other in the left posterotemporal region. Open biopsy revealed Balamuthia encephalitis. The patient was treated with combination antibiotics (pentamidine, 300 mg intravenously once a day; sulfadiazine, 1.5 g 4 times a day; fluconazole, 400 mg once a day; and clarithromycin, 500 mg 3 times a day) and was discharged home. There have been no significant neurological sequelae at this writing (6 months after biopsy). We present this case with unusual clinical course to raise awareness of this infectious disease, which may have a more favorable outcome if diagnosed and treated in its early states.


Cancer and Metabolism | 2015

Treatment of glioma patients with ketogenic diets: report of two cases treated with an IRB-approved energy-restricted ketogenic diet protocol and review of the literature.

Kenneth A. Schwartz; Howard T. Chang; Michele Nikolai; Joseph Pernicone; Sherman Rhee; Karl Olson; Peter C. Kurniali; Norman G. Hord; Mary Noel

BackgroundBased on the hypothesis that cancer cells may not be able to metabolize ketones as efficiently as normal brain cells, the ketogenic diet (KD) has been proposed as a complementary or alternative therapy for treatment of malignant gliomas.Case presentationWe report here our experience in treating two glioma patients with an IRB-approved energy-restricted ketogenic diet (ERKD) protocol as monotherapy and review the literature on KD therapy for human glioma patients. An ERKD protocol was used in this pilot clinical study. In addition to the two patients who enrolled in this study, we also reviewed findings from 30 other patients, including 5 patients from case reports, 19 patients from a clinical trial reported by Rieger and 6 patients described by Champ. A total of 32 glioma patients have been treated using several different KD protocols as adjunctive/complementary therapy. The two patients who enrolled in our ERKD pilot study were monitored with twice daily measurements of blood glucose and ketones and daily weights. However, both patients showed tumor progression while on the ERKD therapy. Immunohistochemistry reactions showed that their tumors had tissue expression of at least one of the two critical mitochondrial ketolytic enzymes (succinyl CoA: 3-oxoacid CoA transferase, beta-3-hydroxybutyrate dehydrogenase 1). The other 30 glioma patients in the literature were treated with several different KD protocols with varying responses. Prolonged remissions ranging from more than 5 years to 4 months were reported in the case reports. Only one of these patients was treated using KD as monotherapy. The best responses reported in the more recent patient series were stable disease for approximately 6 weeks. No major side effects due to KD have been reported in any of these patients.ConclusionsWe conclude that 1. KD is safe and without major side effects; 2. ketosis can be induced using customary foods; 3. treatment with KD may be effective in controlling the progression of some gliomas; and 4. further studies are needed to determine factors that influence the effectiveness of KD, whether as a monotherapy, or as adjunctive or supplemental therapy in treating glioma patients.Trial registrationClinicalTrials.gov# NCT01535911


Nutrition & Metabolism | 2013

Ketolytic and glycolytic enzymatic expression profiles in malignant gliomas: implication for ketogenic diet therapy

Howard T. Chang; Lawrence Karl Olson; Kenneth A. Schwartz

BackgroundRecent studies in animal models, based on the hypothesis that malignant glioma cells are more dependent on glycolysis for energy generation, have shown promising results using ketogenic diet (KD) therapy as an alternative treatment strategy for malignant glioma, effectively starving glioma cells while providing ketone bodies as an energy source for normal neurons and glial cells. In order to test this treatment strategy in humans, we investigated the relative expression of several key enzymes involved in ketolytic and glycolytic metabolism in human anaplastic glioma (WHO grade III) and glioblastoma (GBM, WHO grade IV).MethodsImmunohistochemistry was performed on formalin fixed paraffin embedded sections from 22 brain biopsies (17 GBM, 3 anaplastic astrocytoma and 2 anaplastic oligoastrocytoma) using antibodies raised against glycolytic and ketolytic enzymes. The glycolytic enzymes included hexokinase-II (HK2) and pyruvate kinase M2 isoform (PKM2). The ketone body metabolic enzymes included: succinyl CoA: 3-oxoacid CoA transferase (OXCT1), 3-hydroxybutyrate dehydrogenase 1 and 2 (BDH1 and BDH2), and acetyl-CoA acetyltransferase 1 (ACAT1). The immunoreactivities were graded using a semi-quantitative scale based on the percentage of positive cells: POS (>20%), LOW (5-20%), and very low (VLOW) (<5%). Focal non-neoplastic “normal” brain tissue within the biopsy specimens served as internal controls.ResultsThe rate limiting mitochondrial ketolytic enzymes (OXCT1 and BDH1) were either LOW or VLOW, concordantly in 14 of the 17 GBMs and in 1 of 5 anaplastic gliomas, whereas at least one of the glycolytic enzymes was POS in 13 of these 17 GBMs and all 5 anaplastic gliomas. Cytosolic BDH2 and mitochondrial ACTAT1 were, surprisingly, POS in most of these tumors.ConclusionOur results showing that malignant gliomas have differential expression of ketolytic and glycolytic enzymes are consistent with previous studies that have shown that these are genetically heterogeneous tumors. It seems reasonable to hypothesize that patients with low or very low expression of key ketolytic enzymes in their malignant gliomas may respond better to the KD therapy than those patients with positive expression of these enzymes. Further studies in animal models and/or a large-scale clinical trial would be needed to test this hypothesis.


Spinal Cord | 2007

Subacute human spinal cord contusion: few lymphocytes and many macrophages

Howard T. Chang

Study design:Clinicopathological correlation of three cases of subacute cervical spinal cord contusions.Objective:To correlate the pathology of subacute cervical spinal cord injury (SCI) with imaging and clinical-functional studies, and to compare with findings from previous human SCI studies and animal models of SCI.Setting:Department of Pathology, SUNY-Upstate Medical University, Syracuse, NY, USA.Method:Post mortem pathology report.Case report/Results:The clinical, radiological, and pathological findings of three cases of subacute spinal cord contusions are described in detail. The postinjury survival periods were 15, 20, and 60 days, respectively. Extensive microglia/macrophage infiltrations without significant lymphocytes are seen in all cases. Free radical injury as assessed by immunocytochemistry for 4-hydroxynonenal and nitrotyrosine showed a labeling pattern parallel to that of the macrophage distribution at 15 days, but no significant labeling in the injury sites at 20 and 60 days.Conclusion:The present report, though limited in sample size, shows plenty of activated microglia/macrophages in human SCI up to 60 days postinjury. This observation not only confirms similar findings in previous studies, but also raises an intriguing question of potential interactions between these activated microglia/macrophages and the experimental therapy, proposed by some authors, of injecting exogenously activated macrophages to promote SCI repair. The small number of human SCI cases (in this as well as in most other single medical centers) available for detailed study illustrates the need for the establishment of a consortium of human SCI tissue banks.


Childs Nervous System | 2006

Pediatric cerebellar pleomorphic xanthoastrocytoma with anaplastic features: a case of long-term survival after multimodality therapy

Howard T. Chang; Julius Latorre; Seung S. Hahn; Ronald L. Dubowy; Robert L. Schelper

Case reportA 4-year-old girl had a large midline cerebellar solid and cystic mass partially attached to the meninges. The original diagnosis was glioblastoma multiforme and she was treated by a gross-total surgical resection followed by chemotherapy and radiation theraphy to the posterior fossa during the ensuing 14 months. She has received no further theraphy and appears to be doing well 12 years later. This unusual favorable clinical outcome prompted our review of this case.MethodsAdditional special stains and immunocytochemistry were performed on the paraffin embedded tumor sections.ResultsWe have confirmed the original histopathological observations of hypercellularity and focal nuclear pleomorphism, atypical mitoses, vascular hyperplasia, as well as focal necrosis. However, the additional stains revealed that the tumor is a relatively well-circumscribed meningeal-based astrocytic tumor (positive for GFAP) with extensive reticulin deposit and focal neuronal differentiation (positive for synaptophysin). A Ki67 labeling index is generally very low, but is positive in up to 5-10% of tumor cells focally. In the light of the favorable clinical outcome and the overall histological features, this tumor may be best reclassified as a rare example of cerebellar pleomorphic xanthoastrocytoma with foci of anaplasia.


Pediatric Neurology | 2008

Hemorrhagic colloid cyst in a 9-year-old girl.

Muhammad U. Farooq; Archit Bhatt; Howard T. Chang

Colloid cysts of the third ventricle are benign intracranial tumors that usually become symptomatic in adults, rather than in children. Rare hemorrhages in these cysts can cause acute obstructive hydrocephalus and sudden death. We report a novel pediatric case of hemorrhagic colloid cyst in a 9-year-old girl who presented with headaches, nausea, and had sudden deterioration of her mental status. The patient underwent emergent ventriculostomy and then craniotomy to resect the colloid cyst; she had an excellent recovery.


Archive | 1989

Intracellular Labeling and Immunocytochemistry

Stephen T. Kitai; G. Richard Penny; Howard T. Chang

Since its introduction in 1976 (Cullheim and Kellerth, 1976; Jankowska et al., 1976; Kitai et al., 1976; Light and Durkovic, 1976; Snow et al., 1976), the method of intracellular injection of horseradish peroxidase (HRP) has established itself as an enormously productive tool for neurobiology (Kitai and Bishop, 1981; Kitai and Wilson, 1982). The fundamental advantage of the technique is that it allows direct correspondence between cellular physiology and morphology to be established. First, as a physiological tool, the HRP-filled microelectrode is suitable for the analysis of any neurophysiological property of a neuron that can be assayed by intracellular recording. Second, as a morphological tool, intracellular iontophoresis of HRP fills and labels the entire extent of a neuron, including soma, dendrites, dendritic specializations such as spines, and as much of the axon, axonal collaterals, and terminals as survival time permits. The morphological rendition of the HRP-filled neuron revealed by enzyme histochemistry is equal to or better than the results of the very best Golgi stains.


Journal of Neuropathology and Experimental Neurology | 2015

Disrupting NOTCH Slows Diffuse Intrinsic Pontine Glioma Growth, Enhances Radiation Sensitivity, and Shows Combinatorial Efficacy With Bromodomain Inhibition.

Isabella Taylor; Marianne Hütt-Cabezas; William D. Brandt; Madhuri Kambhampati; Javad Nazarian; Howard T. Chang; Katherine E. Warren; Charles G. Eberhart; Eric Raabe

Abstract NOTCH regulates stem cells during normal development and stemlike cells in cancer, but the roles of NOTCH in the lethal pediatric brain tumor diffuse intrinsic pontine glioma (DIPG) remain unknown. Because DIPGs express stem cell factors such as SOX2 and MYCN, we hypothesized that NOTCH activity would be critical for DIPG growth. We determined that primary DIPGs expressed high levels of NOTCH receptors, ligands, and downstream effectors. Treatment of the DIPG cell lines JHH-DIPG1 and SF7761 with the &ggr;-secretase inhibitor MRK003 suppressed the level of the NOTCH effectors HES1, HES4, and HES5; inhibited DIPG growth by 75%; and caused a 3-fold induction of apoptosis. Short hairpin RNAs targeting the canonical NOTCH pathway caused similar effects. Pretreatment of DIPG cells with MRK003 suppressed clonogenic growth by more than 90% and enhanced the efficacy of radiation therapy. The high level of MYCN in DIPG led us to test sequential therapy with the bromodomain inhibitor JQ1 and MRK003, and we found that JQ1 and MRK003 inhibited DIPG growth and induced apoptosis. Together, these results suggest that dual targeting of NOTCH and MYCN in DIPG may be an effective therapeutic strategy in DIPG and that adding a &ggr;-secretase inhibitor during radiation therapy may be efficacious initially or during reirradiation.


Veterinary Pathology | 2012

Toxic equine parkinsonism: an immunohistochemical study of 10 horses with nigropallidal encephalomalacia.

Howard T. Chang; W. Rumbeiha; J. S. Patterson; B. Puschner; A. P. Knight

Chronic ingestion of yellow star thistle (Centaurea solstitialis) or Russian knapweed (Acroptilon repens) causes nigropallidal encephalomalacia (NPE) in horses with an abrupt onset of neurologic signs characterized by dystonia of lips and tongue, inability to prehend food, depression, and locomotor deficits. The objectives of this study were to reexamine the pathologic alterations of NPE and to conduct an immunohistochemistry study using antibodies to tyrosine hydroxylase and α-synuclein, to determine whether NPE brains show histopathologic features resembling those in human Parkinson disease. Results confirm that the NPE lesions are located within the substantia nigra pars reticulata, sparing the cell bodies of the dopaminergic neurons in the substantia nigra pars compacta, and in the rostral portion of the globus pallidus, with partial disruption of dopaminergic (tyrosine hydroxylase–positive) fibers passing through the globus pallidus. No abnormal cytoplasmic inclusions like the Lewy bodies of human Parkinson disease were seen in these NPE brains. These findings indicate that equine NPE may serve as a large animal model of environmentally acquired toxic parkinsonism, with clinical phenotype directly attributable to lesions in globus pallidus and substantia nigra pars reticulata rather than to the destruction of dopaminergic neurons.


Journal of Hematology & Oncology | 2009

Lymphomatoid granulomatosis masquerading as interstitial pneumonia in a 66-year-old man: a case report and review of literature

Ashima Makol; Kalyan Kosuri; Deimante Tamkus; Wanderley de M Calaca; Howard T. Chang

Lymphomatoid granulomatosis (LG) is a rare, Epstein-Barr virus (EBV)-associated systemic angiodestructive lymphoproliferative disorder that may progress to a diffuse large B cell lymphoma. Pulmonary involvement may mimic other more common lung pathologies including pneumonias. Therapeutic standards have not been established for LG, but rituximab, interferon-α2b (INF-α2b), and chemotherapy have shown to improve symptoms and long term prognosis.We report a case of rapid respiratory deterioration in a 66-year-old man with clinical presentation, chest radiography, pulmonary function testing and high resolution computed tomography (HRCT) findings consistent with idiopathic interstitial pneumonia, but very poor response to antibiotics and low dose steroids. Lung biopsy showed histopathology consistent with LG that was confirmed by a positive in situ hybridization for Epstein - Barr virus encoded RNA (EBER). The patient was treated with rituximab and combination chemotherapy and showed significant initial clinical improvement with gradual resolution of abnormal findings on imaging. However, the patient developed pancytopenia as a complication of chemotherapy and died secondary to septic shock and renal failure that were refractory to medical management. Autopsy showed diffuse alveolar damage but no evidence of any residual LG within the lungs.This case demonstrates that an open lung biopsy or video-assisted thoracoscopic surgical (VATS) biopsy is often necessary to rule out the presence of LG in order to determine the appropriate therapeutic strategy early in the course of illness to improve prognosis.

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Robert L. Schelper

State University of New York Upstate Medical University

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Mary Noel

Michigan State University

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Archit Bhatt

Michigan State University

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Eric Raabe

Johns Hopkins University School of Medicine

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Michele Nikolai

Michigan State University

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Javad Nazarian

Children's National Medical Center

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