Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 28
Filter
Add more filters










Publication year range
1.
J Neurosurg Case Lessons ; 2(19): CASE21331, 2021 Nov 08.
Article in English | MEDLINE | ID: mdl-36061974

ABSTRACT

BACKGROUND: Dural reconstruction to achieve expansion duraplasty is important in suboccipital decompression for Chiari malformation type 1 (CM1). Although various dural substitutes are available, including synthetic collagen matrix grafts and dural xenografts, they have the potential to induce an inflammatory response. In this case series, the authors present their experience and discuss the incidence and possible mechanism of aseptic meningitis after the use of bovine collagen matrix graft as a dural substitute in patients with CM1 after suboccipital decompression. OBSERVATIONS: Three consecutive adult female patients who underwent suboccipital decompression at a single institution by a single neurosurgeon were retrospectively reviewed. They all presented with signs of aseptic meningitis in a delayed fashion, responded well to steroid administration, but had recurrence of their symptoms. Bovine collagen dural substitutes are resorbed in a process that induces an inflammatory response manifesting with signs of aseptic meningitis and is only alleviated with removal of the dural substitute. LESSONS: DuraMatrix Suturable, a dural xenograft derived from bovine dermis, though a viable choice for dural repair, is a potential cause of chemical meningitis after duraplasty in Chiari decompression surgery. In patients presenting with delayed and persistent aseptic meningitis after intervention, removal of this dural substitute led to improved symptomatology.

2.
J Neurol Sci ; 418: 117102, 2020 Nov 15.
Article in English | MEDLINE | ID: mdl-32866816

ABSTRACT

Temozolomide (TMZ) therapy is the standard of care for patients with glioblastoma (GBM). Clinical studies have shown that elevated levels of DNA repair protein O (6)-methylguanine-DNA methyltransferase (MGMT) or deficiency/defect of DNA mismatch repair (MMR) genes is associated with TMZ resistance in some, but not all, GBM tumors. Another reason for GBM treatment failure is signal redundancy due to coactivation of several functionally linked receptor tyrosine kinases (RTKs), including anaplastic lymphoma kinase (ALK) and c-Met (hepatocyte growth factor receptor). As such, these tyrosine kinases serve as potential targets for GBM therapy. Thus, we tested two novel drugs: INC280 (Capmatinib: a highly selective c-Met receptor tyrosine kinase-RTK inhibitor) and LDK378 (Ceritinib: a highly selective anaplastic lymphoma kinase-ALK inhibitor), aiming to overcome TMZ resistance in MGMT-unmethylated GBM cells in in vitro cell culture models. Treatments were examined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, caspase-3 assay and western blot analysis. Results obtained from our experiments demonstrated that preconditioning with INC280 and LDK378 drugs exhibit increased MMR protein expression, specifically MMR protein MLH1 (MutL Homolog 1) and MSH6 (MutS Homolog 6) and sensitized TMZ in MGMT-unmethylated GBM cells via suppression of ALK and c-Met expression. INC280 and LDK378 plus TMZ also induced apoptosis by modulating downstream signaling of PI3K/AKT/STAT3. Taken together, this data indicates that co-inhibition of ALK and c-MET can enhance growth inhibitory effects in MGMT-unmethylated cells and enhance TMZ sensitivity in-vitro, suggesting c-Met inhibitors combined with ALK-targeting provide a therapeutic benefit in MGMT-unmethylated GBM patients.


Subject(s)
Brain Neoplasms , Glioblastoma , Pharmaceutical Preparations , Antineoplastic Agents, Alkylating/pharmacology , Antineoplastic Agents, Alkylating/therapeutic use , Benzamides , Brain Neoplasms/drug therapy , Brain Neoplasms/genetics , Cell Line, Tumor , DNA Modification Methylases/genetics , DNA Repair Enzymes/genetics , Drug Resistance, Neoplasm/genetics , Glioblastoma/drug therapy , Glioblastoma/genetics , Humans , Imidazoles , Phosphatidylinositol 3-Kinases , Pyrimidines , Sulfones , Temozolomide/pharmacology , Temozolomide/therapeutic use , Triazines , Tumor Suppressor Proteins/genetics
3.
Cancer Invest ; 38(6): 349-355, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32441531

ABSTRACT

Background: Meningiomas represent ∼30% of primary central nervous system (CNS) tumors. Although advances in surgery and radiotherapy have significantly improved survival, there remains an important subset of patients whose tumors have more aggressive behavior and are refractory to conventional therapy. Recent advances in molecular genetics and epigenetics suggest that this aggressive behavior may be due to the deletion of the DNA repair and tumor suppressor gene, CHEK2, neurofibromatosis Type 2 (NF2) mutation on chromosome 22q12, and genetic abnormalities in multiple RTKs including FGFRs. Management of higher-grade meningiomas, such as anaplastic meningiomas (AM: WHO grade III), is truly challenging and there isn't an established chemotherapy option. We investigate the effect of active multi tyrosine receptor kinase inhibitor Dovitinib at stopping AM cell growth in in vitro with either frequent codeletion or mutated CHEK2 and NF2 gene.Methods: Treatment effects were assessed using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, western blot analysis, caspases assay, and DNA fragmentation assay.Results: Treatment of CH157MN and IOMM-Lee cells with Dovitinib suppressed multiple angiokinases-mainly FGFRs, leading to suppression of downstream signaling by RAS-RAF-MAPK molecules and PI3K-AKT molecules which are involved in cell proliferation, cell survival, and tumor invasion. Furthermore, Dovitinib induced apoptosis via downregulation of survival proteins (Bcl-XL), and over-expression of apoptotic factors (Bax and caspase-3) regardless of CHEK2 and NF2 mutation status.Conclusions: This study establishes the groundwork for the development of Dovitinib as a therapeutic agent for high-grade AM with either frequent codeletion or mutated CHEK2 and NF2, an avenue with high translational potential.


Subject(s)
Benzimidazoles/pharmacology , Checkpoint Kinase 2/genetics , Meningioma/drug therapy , Neurofibromin 2/genetics , Quinolones/pharmacology , Apoptosis/drug effects , Caspase 3/genetics , Cell Line, Tumor , Cell Proliferation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Meningioma/genetics , Meningioma/pathology , Mutation/genetics , Neoplasm Staging , Phosphatidylinositol 3-Kinases/genetics , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-akt/genetics , Receptors, Fibroblast Growth Factor/antagonists & inhibitors , Receptors, Fibroblast Growth Factor/genetics , Signal Transduction/drug effects , bcl-2-Associated X Protein/genetics , bcl-X Protein/genetics
4.
Cancer Chemother Pharmacol ; 82(6): 945-952, 2018 12.
Article in English | MEDLINE | ID: mdl-30209569

ABSTRACT

PURPOSE/INTRODUCTION: Glioblastoma (GB) remains incurable despite aggressive chemotherapy, radiotherapy, and surgical interventions; immunotherapies remain experimental in clinical practice. Relevant preclinical models that can accurately predict tumor response to therapy are equally challenging. This study aimed to validate the effect of the naturally occurring agent diallyl trisulfide (DATS) in human GB in relevant pre-clinical models. METHODS: Ex vivo slice culture, in vivo cell line derived orthotopic xenograft and patient-derived orthotopic xenograft (PDX) animal models of GB were utilized to assess efficacy of treatment with DATS. RESULTS: Our results showed 72-h treatments of 25 µM DATS induced cell death in ex vivo human GB slice culture. We treated U87MG orthotopic xenograft models (U87MGOX) and patient-derived orthotopic xenograft models (PDX) with daily intraperitoneal injections of DATS for 14 days. Magnetic resonance (MR) imaging of mice treated with DATS (10 mg/kg) demonstrated reduced tumor size at 5 weeks when compared with saline-treated U87MGOX and PDX controls. Hematoxylin (H&E) staining demonstrated dose-dependent reduction in gross tumor volume with decreased proliferation and decreased angiogenesis. Western blotting showed that DATS was associated with increases in histone acetylation (Ac-Histone H3/H4) and activated caspase-3 in this novel preclinical model. Histological assessment and enzyme assays showed that even the highest dose of DATS did not negatively impact hepatic function. CONCLUSIONS: DATS may be an effective and well-tolerated therapeutic agent in preventing tumor progression and inducing apoptosis in human GB.


Subject(s)
Allyl Compounds/therapeutic use , Glioblastoma/drug therapy , Histone Deacetylase Inhibitors/therapeutic use , Histone Deacetylases/metabolism , Sulfides/therapeutic use , Allyl Compounds/administration & dosage , Animals , Apoptosis/drug effects , Astrocytes/drug effects , Astrocytes/pathology , Cell Line, Tumor , Dose-Response Relationship, Drug , Glioblastoma/enzymology , Glioblastoma/pathology , Histone Deacetylase Inhibitors/administration & dosage , Humans , Male , Mice, SCID , Neurons/drug effects , Neurons/pathology , Sulfides/administration & dosage , Xenograft Model Antitumor Assays
5.
World Neurosurg ; 117: 242-245, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29929032

ABSTRACT

BACKGROUND: The authors report the case of a 76-year-old woman presenting with leg pain, numbness, and weakness mimicking a lumbosacral radiculopathy. CASE DESCRIPTION: Initial lumbar spine magnetic resonance imaging demonstrated mild root compression, but lumbar decompression afforded only transient symptomatic relief. Postoperative magnetic resonance imaging of the lumbosacral plexus and sciatic nerve revealed a gluteal venous varix compressing the sciatic nerve just distal to the piriformis muscle. Neurolysis and surgical resection of the offending varix resulted in resolution of her symptoms. CONCLUSIONS: Variceal compression is a rare cause of extraspinal origin of lower extremity radicular pain. It should be considered if there is lack of correlation between radiologic findings and the clinical picture or if there is a failure of response to treatment of the assumed spinal cause.


Subject(s)
Nerve Compression Syndromes/etiology , Sciatica/etiology , Varicose Veins/complications , Aged , Decompression, Surgical , Diagnosis, Differential , Female , Humans , Lumbar Vertebrae/diagnostic imaging , Lumbar Vertebrae/surgery , Nerve Compression Syndromes/diagnostic imaging , Nerve Compression Syndromes/surgery , Reoperation , Sciatic Nerve/diagnostic imaging , Sciatica/diagnostic imaging , Sciatica/surgery , Varicose Veins/diagnostic imaging , Varicose Veins/surgery
6.
Neurol India ; 66(3): 678, 2018.
Article in English | MEDLINE | ID: mdl-29766925

Subject(s)
Hemangioblastoma , Animals , Birds , Brain
7.
Biotechnol J ; 13(1)2018 Jan.
Article in English | MEDLINE | ID: mdl-28881095

ABSTRACT

Polymeric nanoparticles have been extensively studied as drug delivery vehicles both in vitro and in vivo for the last two decades. In vitro methods to assess drug release profiles usually utilize degradation of nanoparticles in aqueous medium, followed by the measurement of the concentration of the released drug. This method, however, is difficult to use for drugs that are poorly water soluble. In this study, a protocol for measuring drug release kinetic using albumin solution as the medium is described. Albumin is a major blood transport protein, which mediates transport of many lipid soluble compounds including fatty acids, hormones, and bilirubin. The use of a dialysis-based system utilizing albumin dialysate solution allows hydrophobic drug release from a diverse set of drug delivery modalities is demonstrated. The method using liposomes and PLGA nanoparticles as drug carriers, and two model hydrophobic drugs, 17ß-estradiol, and dexamethasone is validated.


Subject(s)
Drug Carriers/chemistry , Drug Delivery Systems , Drug Liberation , Nanoparticles/chemistry , Albumins/chemistry , Dexamethasone/chemistry , Drug Carriers/therapeutic use , Humans , Hydrophobic and Hydrophilic Interactions , Kinetics , Lipids/chemistry , Liposomes/chemistry , Nanoparticles/therapeutic use , Polymers/chemistry , Solutions/chemistry , Water/chemistry
8.
J Neurosurg ; 125(3): 598-602, 2016 09.
Article in English | MEDLINE | ID: mdl-26771846

ABSTRACT

Peripheral nerve involvement may be the first sign of systemic amyloid light-chain (AL) amyloidosis, a rare disease. Physical examination and electrodiagnostic testing are the mainstays of peripheral neuropathy evaluation at presentation. Sural nerve biopsy is performed in conjunction with serum and urine protein evaluation to differentiate between focal and systemic disease. Systemic disease is treated with a combination of chemotherapy, steroids, and stem cell transplantation. Isolated peripheral nerve disease is extremely rare. The authors here report the case of an 80-year-old woman who presented with progressive right upper-extremity weakness due to right radial neuropathy discovered upon electrodiagnostic testing. Magnetic resonance neurography (MRN) revealed a focal lesion within the right radial nerve. She underwent radial nerve exploration and excision of an intraneural mass consisting of amyloid on histopathology, with mass spectrometry analysis diagnostic for AL amyloidosis. Noninvasive testing and clinical history did not suggest systemic involvement. This unique case of isolated peripheral nerve AL amyloidosis in the absence of signs and symptoms of systemic disease is described, and the literature demonstrating peripheral nerve involvement in AL amyloidosis is reviewed.


Subject(s)
Immunoglobulin Light-chain Amyloidosis/diagnosis , Radial Neuropathy/diagnosis , Aged, 80 and over , Female , Humans
9.
Tumour Biol ; 37(6): 7525-34, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26684801

ABSTRACT

Radiation-induced necrosis (RN) is a relatively common side effect of radiation therapy for glioblastoma. However, the molecular mechanisms involved and the ways RN mechanisms differ from regulated cell death (apoptosis) are not well understood. Here, we compare the molecular mechanism of cell death (apoptosis or necrosis) of C6 glioma cells in both in vitro and in vivo (C6 othotopically allograft) models in response to low and high doses of X-ray radiation. Lower radiation doses were used to induce apoptosis, while high-dose levels were chosen to induce radiation necrosis. Our results demonstrate that active caspase-8 in this complex I induces apoptosis in response to low-dose radiation and inhibits necrosis by cleaving RIP1 and RI. When activation of caspase-8 was reduced at high doses of X-ray radiation, the RIP1/RIP3 necrosome complex II is formed. These complexes induce necrosis through the caspase-3-independent pathway mediated by calpain, cathepsin B/D, and apoptosis-inducing factor (AIF). AIF has a dual role in apoptosis and necrosis. At high doses, AIF promotes chromatinolysis and necrosis by interacting with histone H2AX. In addition, NF-κB, STAT-3, and HIF-1 play a crucial role in radiation-induced inflammatory responses embedded in a complex inflammatory network. Analysis of inflammatory markers in matched plasma and cerebrospinal fluid (CSF) isolated from in vivo specimens demonstrated the upregulation of chemokines and cytokines during the necrosis phase. Using RIP1/RIP3 kinase specific inhibitors (Nec-1, GSK'872), we also establish that the RIP1-RIP3 complex regulates programmed necrosis after either high-dose radiation or TNF-α-induced necrosis requires RIP1 and RIP3 kinases. Overall, our data shed new light on the relationship between RIP1/RIP3-mediated programmed necrosis and AIF-mediated caspase-independent programmed necrosis in glioblastoma.


Subject(s)
Gamma Rays/adverse effects , Glioblastoma/radiotherapy , Necrosis/metabolism , Necrosis/pathology , Protein Serine-Threonine Kinases/metabolism , Radiation Injuries/metabolism , Radiation Injuries/pathology , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , Animals , Apoptosis , Biomarkers, Tumor/metabolism , Blotting, Western , Caspases , Cell Proliferation , Glioblastoma/metabolism , Glioblastoma/pathology , Immunoenzyme Techniques , Male , Necrosis/etiology , Radiation Injuries/etiology , Rats , Rats, Sprague-Dawley , Signal Transduction , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
10.
Cancer Growth Metastasis ; 8: 51-60, 2015.
Article in English | MEDLINE | ID: mdl-26648752

ABSTRACT

Glioblastoma (GB) is the most common malignant brain tumor. Drug resistance frequently develops in these tumors during chemotherapy. Therefore, predicting drug response in these patients remains a major challenge in the clinic. Thus, to improve the clinical outcome, more effective and tolerable combination treatment strategies are needed. Robust experimental evidence has shown that the main reason for failure of treatments is signal redundancy due to coactivation of several functionally linked receptor tyrosine kinases (RTKs), including anaplastic lymphoma kinase (ALK), c-Met (hepatocyte growth factor receptor), and oncogenic c-ros oncogene1 (ROS1: RTK class orphan) fusion kinase FIG (fused in GB)-ROS1. As such, these could be attractive targets for GB therapy. The study subjects consisted of 19 patients who underwent neurosurgical resection of GB tissues. Our in vitro and ex vivo models promisingly demonstrated that treatments with crizotinib (PF-02341066: dual ALK/c-Met inhibitor) and temozolomide in combination induced synergistic antitumor activity on FIG-ROS1-positive GB cells. Our results also showed that ex vivo FIG-ROS1+ slices (obtained from GB patients) when cultured were able to preserve tissue architecture, cell viability, and global gene-expression profiles for up to 14 days. Both in vitro and ex vivo studies indicated that combination blockade of FIG, p-ROS1, p-ALK, and p-Met augmented apoptosis, which mechanistically involves activation of Bim and inhibition of survivin, p-Akt, and Mcl-1 expression. However, it is important to note that we did not see any significant synergistic effect of crizotinib and temozolomide on FIG-ROS1-negative GB cells. Thus, these ex vivo culture results will have a significant impact on patient selection for clinical trials and in predicting response to crizotinib and temozolomide therapy. Further studies in different animal models of FIG-ROS1-positive GB cells are warranted to determine useful therapies for the management of human GBs.

11.
Tumour Biol ; 36(9): 7027-34, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25864108

ABSTRACT

Recurrent meningiomas constitute an uncommon but significant problem after standard (surgery and radiation) therapy failure. Current chemotherapies (hydroxyurea, RU-486, and interferon-α) are only of marginal benefit. There is an urgent need for more effective treatments for meningioma patients who have failed surgery and radiation therapy. Limonin, Tangeritin, Zerumbone, 6-Gingerol, Ganoderic Acid A, and Ganoderic Acid DM are some of the plant derivatives that have anti-tumorgenic properties and cause cell death in meningioma cells in vitro. Due to its ease of administration, long-term tolerability, and low incidence of long-term side effects, we explored its potential as a therapeutic agent against meningiomas by examining their efficacy in vitro against meningioma cells. Treatment effects were assessed using MTT assay, Western blot analysis, caspases assay, and DNA fragmentation assay. Results indicated that treatments of IOMM-Lee and CH157MN meningioma cells with Limonin, Tangeritin, Zerumbone, 6-Gingerol, Ganoderic Acid A, and Ganoderic Acid DM induced apoptosis with enhanced phosphorylation of glycogen synthase kinase 3 ß (GSK3ß) via inhibition of the Wnt5/ß-catenin pathway. These drugs did not induce apoptosis in normal human neurons. Other events in apoptosis included downregulation of tetraspanin protein (TSPAN12), survival proteins (Bcl-XL and Mcl-1), and overexpression apoptotic factors (Bax and caspase-3). These results provide preliminary strong evidence that medicinal plants containing Limonin, Tangeritin, 6-Gingerol, Zerumbone, Ganoderic Acid A, and Ganoderic Acid DM can be applied to high-grade meningiomas as a therapeutic agent, and suggests that further in vivo studies are necessary to explore its potential as a therapeutic agent against malignant meningiomas.


Subject(s)
Catechols/administration & dosage , Fatty Alcohols/administration & dosage , Flavones/administration & dosage , Heptanoic Acids/administration & dosage , Lanosterol/analogs & derivatives , Limonins/administration & dosage , Meningioma/drug therapy , Sesquiterpenes/administration & dosage , Triterpenes/administration & dosage , Apoptosis/drug effects , Catechols/chemistry , Cell Line, Tumor , DNA Fragmentation/drug effects , Fatty Alcohols/chemistry , Flavones/chemistry , Glycogen Synthase Kinase 3/biosynthesis , Glycogen Synthase Kinase 3/genetics , Glycogen Synthase Kinase 3 beta , Heptanoic Acids/chemistry , Humans , Lanosterol/administration & dosage , Lanosterol/chemistry , Limonins/chemistry , Meningioma/genetics , Meningioma/pathology , Sesquiterpenes/chemistry , Triterpenes/chemistry , Wnt Signaling Pathway/drug effects
12.
Anticancer Res ; 35(2): 615-25, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25667438

ABSTRACT

Glioblastoma is the most common and deadliest of malignant primary brain tumors (Grade IV astrocytoma) in adults. Current standard treatments have been improving but patient prognosis still remains unacceptably devastating. Glioblastoma recurrence is linked to epigenetic mechanisms and cellular pathways. Thus, greater knowledge of the cellular, genetic and epigenetic origin of glioblastoma is the key for advancing glioblastoma treatment. One rapidly growing field of treatment, epigenetic modifiers; histone deacetylase inhibitors (HDACis), has now shown much promise for improving patient outcomes through regulation of the acetylation states of histone proteins (a form of epigenetic modulation) and other non-histone protein targets. HDAC inhibitors have been shown, in a pre-clinical setting, to be effective anticancer agents via multiple mechanisms, by up-regulating expression of tumor suppressor genes, inhibiting oncogenes, inhibiting tumor angiogenesis and up-regulating the immune system. There are many HDAC inhibitors that are currently in pre-clinical and clinical stages of investigation for various types of cancers. This review will explain the theory of epigenetic cancer therapy, identify HDAC inhibitors that are being investigated for glioblastoma therapy, explain the mechanisms of therapeutic effects as demonstrated by pre-clinical and clinical studies and describe the current status of development of these drugs as they pertain to glioblastoma therapy.


Subject(s)
Epigenesis, Genetic , Glioblastoma/drug therapy , Histone Deacetylase Inhibitors/therapeutic use , Benzamides/therapeutic use , Fatty Acids/therapeutic use , Humans , Hydroxamic Acids/therapeutic use , Oligopeptides/therapeutic use
13.
Article in English | MEDLINE | ID: mdl-25485306

ABSTRACT

Meningiomas are by far the most common tumors arising from the meninges. A myriad of aberrant signaling pathways involved with meningioma tumorigenesis, have been discovered. Understanding these disrupted pathways will aid in deciphering the relationship between various genetic changes and their downstream effects on meningioma pathogenesis. An understanding of the genetic and molecular profile of meningioma would provide a valuable first step towards developing more effective treatments for this intracranial tumor. Chromosomes 1, 10, 14, 22, their associated genes, and other potential targets have been linked to meningioma proliferation and progression. It is presumed that through an understanding of these genetic factors, more educated meningioma treatment techniques can be implemented. Future therapies will include combinations of targeted molecular agents including gene therapy, si-RNA mediation, proton therapy, and other approaches as a result of continued progress in the understanding of genetic and biological changes associated with meningiomas. This review provides an overview of the current knowledge of the genetic, signaling and molecular profile of meningioma and possible treatments strategies associated with such profiles.

14.
J Neurol Neurosurg ; 1(1)2014 Apr 05.
Article in English | MEDLINE | ID: mdl-25346943

ABSTRACT

Glioblastoma is a form of brain tumor with a very high morbidity and mortality. Despite decades of research, the best treatments currently in clinical practice only extend survival by a number of months. A promising alternative to conventional treatment for glioblastomas is immunotherapy. Although proposed over a century ago, the field of cancer immunotherapy has historically struggled to translate it into effective clinical treatments. Better understanding is needed of the various regulatory and co-stimulatory factors in the glioblastoma patient for more efficient immunotherapy treatments. The tumor microenvironment is anatomically shielded from normal immune-surveillance by the blood-brain barrier, irregular lymphatic drainage system, and it's in a potently immunosuppressive environment. Immunotherapy can potentially manipulate these forces effectively to enhance anti-tumor immune response and clinical benefit. New treatments utilizing the immune system show promise in terms of targeting and efficacy. This review article attempts to discuss current practices in glioblastoma treatment, the theory behind immunotherapy, and current research into various clinical trials.

15.
J Neurooncol ; 114(1): 43-50, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23754639

ABSTRACT

Glioblastoma, the most lethal brain tumor, remains incurable despite aggressive chemotherapy and surgical interventions. New chemotherapeutics for glioblastoma have been explored in preclinical models and some agents have reached the clinical setting. However, success rates are not significant. Previous investigations involving diallyl trisulfide (DATS), a garlic compound, indicated significant anti-cancer effects in glioblastoma in vitro. DATS has also been shown to inhibit histone deacetylase activity and impede glioblastoma tumor progression. We hypothesized that DATS would block ectopic U87MG tumor by multiple pro-apoptotic pathways via inhibiting histone deacetylase (HDAC). To prove this, we developed ectopic U87MG tumors in SCID mice and treated them daily with intraperitoneal injections of DATS for 7 days. Results indicated that DATS (10 µg/kg-10 mg/kg) dose-dependently reduced tumor mass and number of mitotic cells within tumors. Histological and biochemical assays demonstrated that DATS reduced mitosis in tumors, decreased HDAC activity, increased acetylation of H3 and H4, inhibited cell cycle progression, decreased pro-tumor markers (e.g., survivin, Bcl-2, c-Myc, mTOR, EGFR, VEGF), promoted apoptotic factors (e.g., bax, mcalpian, active caspase-3), and induced DNA fragmentation. Our data also demonstrated an increase in p21Waf1 expression, which correlated with increased p53 expression and MDM2 degradation following DATS treatment. Finally, histological assessment and enzyme assays showed that even the highest dose of DATS did not negatively impact hepatic function. Collectively, our results clearly demonstrated that DATS could be an effective therapeutic agent in preventing tumor progression and inducing apoptosis in human glioblastoma in vivo, without impairing hepatic function.


Subject(s)
Allyl Compounds/therapeutic use , Apoptosis/drug effects , Brain Neoplasms/drug therapy , Glioblastoma/drug therapy , Histone Deacetylases/metabolism , Sulfides/therapeutic use , Analysis of Variance , Animals , Apoptosis Regulatory Proteins/genetics , Apoptosis Regulatory Proteins/metabolism , Cell Line, Tumor , Disease Models, Animal , Disease Progression , Gene Expression Regulation, Neoplastic/drug effects , Humans , In Situ Nick-End Labeling , Liver/pathology , Mice , Mice, SCID , Xenograft Model Antitumor Assays
16.
Neurochem Res ; 38(5): 895-905, 2013 May.
Article in English | MEDLINE | ID: mdl-23462880

ABSTRACT

The incidence of acute and chronic spinal cord injury (SCI) in the United States is more than 10,000 per year, resulting in 720 cases per million persons enduring permanent disability each year. The economic impact of SCI is estimated to be more than 4 billion dollars annually. Preclinical studies, case reports, and small clinical trials suggest that early treatment may improve neurological recovery. To date, no proven therapeutic modality exists that has demonstrated a positive effect on neurological outcome. Emerging data from recent preclinical and clinical studies offer hope for this devastating condition. This review gives an overview of current basic research and clinical studies for the treatment of SCI.


Subject(s)
Spinal Cord Injuries , Clinical Trials as Topic , Humans , Spinal Cord Injuries/epidemiology , Spinal Cord Injuries/physiopathology , Spinal Cord Injuries/therapy , United States/epidemiology
17.
Head Neck ; 35(6): E197-201, 2013 Jun.
Article in English | MEDLINE | ID: mdl-22367919

ABSTRACT

BACKGROUND: Esophageal strictures are a common sequela of chemoradiation and/or surgery to the head and neck cancers and can lead to stenosis and significant dysphagia. Endoscopic dilation endoscopic and placement of self-expanding stents are often to used relieve dysphagia symptoms. However, these stents are not without risks and complications. METHODS: We present a case of a 58-year-old man who had the rare complication of cervical osteomyelitis as a result of plastic esophageal stent placement for palliation of chemoradiation-induced strictures. RESULTS: The patient was successfully managed with immobilization of the cervical spine in a halo vest and appropriate antibiotics. CONCLUSION: To the best of our knowledge, this is the first reported case of cervical spine osteomyelitis after self-expanding plastic stent (SEPS) placement for esophageal stricture. It was successfully treated with immobilization and antibiotic therapy. The treating physician should be aware of this rare complication to make an early diagnosis. Literature on esophageal stent-induced cervical osteomyelitis is reviewed.


Subject(s)
Chemoradiotherapy, Adjuvant/adverse effects , Esophageal Stenosis/surgery , Osteomyelitis/etiology , Palliative Care , Stents/adverse effects , Anti-Bacterial Agents/therapeutic use , Carcinoma, Squamous Cell/therapy , Cefepime , Cephalosporins/therapeutic use , Deglutition Disorders/etiology , Deglutition Disorders/surgery , Esophageal Stenosis/complications , Esophageal Stenosis/etiology , Humans , Male , Middle Aged , Osteomyelitis/drug therapy , Pharyngeal Neoplasms/therapy , Vancomycin/therapeutic use
18.
J Pineal Res ; 54(1): 58-68, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22823500

ABSTRACT

Melatonin has shown particular promise as a neuroprotective agent to prevent motoneuron death in animal models of both amyotrophic lateral sclerosis (ALS) and spinal cord injuries (SCI). However, an understanding of the roles of endogenous melatonin receptors including MT1, MT2, and orphan G-protein receptor 50 (GPR50) in neuroprotection is lacking. To address this deficiency, we utilized plasmids for transfection and overexpression of individual melatonin receptors in the ventral spinal cord 4.1 (VSC4.1) motoneuron cell line. Receptor-mediated cytoprotection following exposure to glutamate at a toxic level (25 µm) was determined by assessing cell viability, apoptosis, and intracellular free Ca(2+) levels. Our findings indicate a novel role for MT1 and MT2 for increasing expression of the calcium-binding proteins calbindin D28K and parvalbumin. Increased levels of calbindin D28K and parvalbumin in VSC4.1 cells overexpressing MT1 and MT2 were associated with cytoprotective effects including inhibition of proapoptotic signaling, downregulation of inflammatory factors, and expression of prosurvival markers. Interestingly, the neuroprotective effects conferred by overexpression of MT1 and/or MT2 were also associated with increases in the estrogen receptor ß (ERß): estrogen receptor α (ERα) ratio and upregulation of angiogenic factors. GPR50 did not exhibit cytoprotective effects. To further confirm the involvement of the melatonin receptors, we silenced both MT1 and MT2 in VSC4.1 cells using RNA interference technology. Knockdown of MT1 and MT2 led to an increase in glutamate toxicity, which was only partially reversed by melatonin treatment. Taken together, our findings suggest that the neuroprotection against glutamate toxicity exhibited by melatonin may depend on MT1 and MT2 but not GPR50.


Subject(s)
Glutamic Acid/toxicity , Motor Neurons/drug effects , Receptors, Melatonin/biosynthesis , Animals , Apoptosis/drug effects , Calbindins/biosynthesis , Cell Line , Cell Survival/drug effects , Gene Knockdown Techniques , Mice , Motor Neurons/metabolism , Nerve Tissue Proteins/drug effects , Neuroprotective Agents/pharmacology , Parvalbumins/biosynthesis , RNA, Small Interfering/pharmacology , Receptor, Melatonin, MT1/genetics , Receptor, Melatonin, MT2/genetics , Receptors, G-Protein-Coupled/drug effects
19.
Spine J ; 12(6): 500-6, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22698998

ABSTRACT

BACKGROUND CONTEXT: Percutaneous vertebroplasty (PV) can provide pain relief and biomechanical stabilization of lytic metastasis of the spine in selected patients. Percutaneous vertebroplasty of the atlas has been reported in only five cases and has been performed with different techniques and approaches. PURPOSE: To describe the technique we used to perform PV of a lytic lesion of the lateral mass of C1 under computed tomography, computed tomography angiography, and computed tomography fluoroscopy guidance with a posterolateral approach, sparing the vertebral artery (VA). STUDY DESIGN/SETTING: Technical note. METHODS: A 36-year-old woman with a history of intestinal carcinoid tumor presented with neck pain refractory to medical treatment. Radiological evaluation showed osteolytic destruction of the left lateral mass of the atlas, at the risk of collapse, with erosion of the VA canal. Under computed tomography and computed tomography angiography guidance, a percutaneous posterolateral oblique approach to the C1 left lateral mass was performed followed by cement augmentation under computed tomography fluoroscopy control. RESULTS: Complete cement filling of the osteolytic lesion was achieved. A cement leak was noted along the horizontal V3 segment of the left VA. Computed tomography angiography scan showed patency of the VA after the procedure. There were no clinical complications. The patient reported substantial pain relief and improved range of motion at 12 hours postprocedure, which remained stable at 2-month follow-up examination. CONCLUSIONS: Computed tomography-guided PV of C1 lytic lesion with posterolateral approach was effective in the described case for pain control and stabilization, and it may be a therapeutic option in selected patients to avoid occipitocervical fusion. This procedure requires good understanding of the anatomy and rigorous technique to avoid potential complications.


Subject(s)
Cervical Atlas/surgery , Orthopedic Procedures/methods , Surgery, Computer-Assisted/methods , Vertebroplasty/methods , Adult , Bone Cements/therapeutic use , Carcinoid Tumor/secondary , Carcinoid Tumor/surgery , Female , Humans , Intestinal Neoplasms/pathology , Spinal Neoplasms/secondary , Spinal Neoplasms/surgery , Tomography, X-Ray Computed
SELECTION OF CITATIONS
SEARCH DETAIL
...