Characterizing the pharmacokinetics of panobinostat in a non-human primate model for the treatment of diffuse intrinsic pontine glioma.

PURPOSE: Diffuse intrinsic pontine glioma (DIPG) is one of the deadliest forms of childhood cancers. To date, no effective treatment options have been developed. Recent drug screening studies identified the HDAC inhibitor panobinostat as an active agent against DIPG cells lines and animal models. To guide in the clinical development of panobinostat, we evaluated the CNS pharmacokinetics of panobinostat using CSF as a surrogate to CNS tissue penetration in a pre-clinical nonhuman primate (NHP) model after oral administration. METHODS: Panobinostat was administered orally to NHP (n = 3) at doses 1.0, 1.8, 2.4, and 3.0 mg/kg (human equivalent dose: 20, 36, 48, 60 mg/m2, respectively). The subjects served as their own controls where possible. Serial, paired CSF and plasma samples were collected for 0-48 h. Panobinostat was quantified via a validated uHPLC-MS/MS method. Pharmacokinetic (PK) parameters were calculated using non-compartmental methods. RESULTS: CSF penetration of panobinostat after systemic delivery was low, with levels detectable in only two subjects. CONCLUSION: The CSF penetration of panobinostat was low following oral administration in this pre-clinical NHP model predictive of human PK.

[Acute intracranial hypertension during xenon anesthesia in a patient with a giant brainstem tumor and cerebrospinal fluid flow obstruction: a case report].

Today there are prospects for the wide use of xenon for anesthesia or analgesic sedation in neurosurgical patients, but clinical trials of and experience in using the agent in neurosurgery are scanty. The paper reports the first case of acute intracranial hypertension during xenon anesthesia in a patient with a giant brain base tumor and cerebrospinal fluid flow obstruction in the presence of subcompensated intracranial hypertension. Comparison of intracranial pressure, blood pressure, cerebral perfusion pressure, and linear blood flow velocity suggests the nature of the effect of xenon on cerebral vascular tone, cerebral blood flow, and its autoregulation. Based on the findings, the authors discuss whether xenon may be used in patients with intracranial hypertension.

Cerebrospinal fluid and serum carcinoembryonic antigen in brain tumors.

Carcinoembryonic antigen (CEA) has been indicated to be a marker for brain tumors. In this study CEA was measured in serum and cerebrospinal fluid (CSF) of 14 patients with benign brain lesions, 16 with primary brain tumors and 8 with metastatic brain tumors by radioimmuno assay. Tumor cyst fluid CEA of 6 patients having intracranial tumors was also measured. The control group (n=20) had no neurological disease. The mean CEA levels in CSF for the control group, patients with benign tumors, primary tumors and metastatic tumors were 0.22 ng/ml, 0.31 ng/ml, 0.92 ng/ml, and 6.3 ng/ml respectively. Corresponding serum CEA levels were 2.5, 2.7, 3.0 and 5.2 ng/ml. Results showed that CEA level in CSF may play an important role in differential diagnosis of primary and metastatic brain tumors and consequently management of the treatment. To our knowledge this is the first such study on brain tumors from India.

Cerebrospinal fluid from a dog with neurologic collapse.

A 3-year-old Staffordshire Terrier was presented to the Texas Veterinary Medical Center with a short progressive history of anorexia, weight loss, and weakness that had progressed to ataxia and collapse with empirical treatment. The dog was tetraparetic and obtunded. Results of a complete neurologic evaluation were consistent with severe, multifocal to diffuse disease involving the forebrain, spinal cord, and brainstem. Cerebrospinal fluid, obtained via cerebellomedullary cisternal puncture, was highly cellular and contained large atypical round cells with small numbers of nondegenerate neutrophils and large mononuclear cells. Rare eosinophils and small lymphocytes were noted. The atypical round cells were approximately 15-25 micro m in diameter with a single nucleus set in a small amount of cytoplasm. The nuclei were typically round to slightly ovoid; however, occasional notched, lobulated, and reniform nuclei were observed. These cells were interpreted as malignant lymphocytes. Owing to a grave prognosis, the animal was euthanized and a necropsy was performed. No gross lesions were found in the central nervous system. Multiple sections of cerebellum, medulla, and spinal cord contained a diffuse neoplastic infiltrate that was predominantly meningeal with rare superficial neuropil invasion. The neoplastic cells were arranged in sheets, cords, and rosettes. Immunohistochemical staining for vimentin, pancytokeratin, CD3, CD79a, synaptophysin, S-100, and neuron-specific enolase was negative; glial fibrillary acidic protein (GFAP) staining was equivocal. Based on histologic findings, a diagnosis of medulloblastoma was made. This case documents the rare occurrence of a canine medulloblastoma and illustrates the difficulty in distinguishing between some embryonal brain tumors and lymphoma.

Cerebrospinal fluid oligoclonal IgG bands in patients with spinal arteriovenous malformation and structural central nervous system lesions.

OBJECTIVE: To investigate the incidence and characteristics of patients with structural central nervous system (CNS) lesions and cerebrospinal fluid oligoclonal IgG bands. DESIGN: A retrospective study. METHOD: The medical records of patients with cerebrospinal fluid oligoclonal IgG bands were evaluated for the presence of structural CNS lesions, their location and cause, and for clinical characteristics. SETTING: Cerebrospinal fluid oligoclonal IgG bands were examined in the Neuroimmunology Laboratory, Hadassah University Hospital, Jerusalem, Israel. PATIENTS: Two hundred seventy of 570 patients with positive cerebrospinal fluid oligoclonal IgG bands were available for analysis. Twenty patients had structural CNS lesions. RESULTS: Twenty (7.5%) of the 270 patients had structural CNS lesions: 3 patients had spinal arteriovenous malformation; 5 patients had tumors; 9 patients had compressive cervical myelopathy. Traumatic leukomalacia, Arnold-Chiari malformation type 1, and CNS hemosiderosis were present in 1 patient each. In 2 patients (1 patient with recurrent meningioma and 1 patient with posttraumatic encephalomalacia) the presence of a structural CNS lesion was followed by the development of multiple sclerosis. In all 3 patients with spinal arteriovenous malformation, oligoclonal IgG identification prolonged the time to diagnosis and therapy, which varied from a few weeks to 3 years. CONCLUSIONS: Structural CNS lesions, responsible for the neurological disorder, were present in 20 patients (7.5%) with cerebrospinal fluid oligoclonal IgG bands. The mechanism underlying oligoclonal IgG presence in spinal arteriovenous malformation and the coexistence of multiple sclerosis and structural CNS lesions is unknown, but may be related to recurrent tissue damage with repeated presentation of CNS antigens to the immune system.