ABSTRACT
State of the art minimally invasive treatments and diagnostics of neurological and cardiovascular diseases demand for flexible instruments and implants that enable sensing and stimulation of bioelectric signals. Besides medical applications, implantable bioelectronic brain-computer interfaces are envisioned as the next step in communication and data transfer. Conventional microelectrode arrays used for these types of applications are based on polymer substrates that are not suitable for biostable, rigid and self-expanding devices. Here, we present fully integrated bioelectrodes on superelastic NiTi carriers fabricated by microsystem technology processes. The insulation between the metallic NiTi structure and the Pt electrode layer is realized by different oxide layers (SiOx, TaOx and Yttrium stabilized Zirconia YSZ). Key properties of bioelectronic implants such as dissolution in body fluids, biocompatibility, mechanical properties and bioelectrical sensing/stimulation capabilities have been investigated by in vitro methods. Particular devices with YSZ are biostable and biocompatible, enabling sensing and stimulation. The major advantage of this system is the combination of medically approved materials and novel fabrication technology that enables miniaturization and integration beyond the state-of-the-art processes. The results demonstrate that this functionalization of superelastic NiTi is an enabling technology for the development of new kinds of bioelectronic devices.
Subject(s)
Biosensing Techniques/instrumentation , Electrochemical Techniques/methods , Electrodes, Implanted , Microelectrodes , Nickel/chemistry , Titanium/chemistry , Alloys/chemistry , Animals , Biocompatible Materials/chemistry , Body Fluids/metabolism , Equipment and Supplies , Humans , Mechanical Phenomena , Microtechnology , Oxides/chemistry , Polymers/chemistry , Prostheses and Implants , Surface PropertiesABSTRACT
Chromosome 10 deletions are among the most common genetic changes in highly malignant glial tumors. It has been noted that loss of heterozygosity (LOH) at 10q23 is a frequent alteration in a variety of human tumors and occurs in approximately 70% of all glioblastomas. By mapping of homozygous deletions on 10q23, a candidate tumor suppressor gene has been isolated, called PTEN for "phosphatase and tensin homolog deleted on chromosome 10" and MMAC1 for "mutated in multiple advanced cancers-1." Mutations of this tumor suppressor gene PTEN/MMAC1 have been reported in anaplastic glial tumors. The objective of this paper was to individuate a prognostic marker in exons 5, 6, 7, and 8 of the PTEN/MMAC1 gene for the high-grade malignant glioma with the most aggressive clinical behavior. In this study, we undertook sequence analysis of these exons in six selected patients with high-grade malignant gliomas who underwent radical aggressive tumor resection followed by radiotherapy within 3 weeks after surgery and subsequent chemotherapy. In them, the exon 5 sequence of the PTEN/MMAC1 gene is suggestive of a genetic survival marker in gliomas with high-grade malignancy.
Subject(s)
Brain Neoplasms/genetics , Brain Neoplasms/mortality , Exons/genetics , Glioma/genetics , Glioma/mortality , Phosphoric Monoester Hydrolases/genetics , Tumor Suppressor Proteins/genetics , Adult , Aged , Anaplasia/genetics , Anaplasia/mortality , Anaplasia/pathology , Brain Neoplasms/pathology , Female , Genetic Markers/genetics , Glioma/pathology , Humans , Male , Middle Aged , Mutation/genetics , PTEN Phosphohydrolase , Polymerase Chain Reaction , Prognosis , Sequence Analysis, DNA , Survival RateABSTRACT
The authors describe a case of large intrathoracic meningocele (16 cm) associated with neurofibromatosis. Computed tomography with metrizamide myelography proved valuable in locating the lesion and in reformation after surgery. The authors make some comments about surgical excision of large meningocele.
Subject(s)
Meningocele/etiology , Neurofibromatoses/complications , Humans , Male , Meningocele/diagnostic imaging , Meningocele/surgery , Metrizamide , Middle Aged , Myelography , Tomography, X-Ray ComputedABSTRACT
Interhemispheric subdural hematoma (ISH) is a rare form of post-traumatic intracranial hemorrhage. The Authors report a further case and review the relevant literature. ISH most frequently gives a clinical picture corresponding to the falx syndrome. The possibility of an interhemispheric hematoma evolving into a chronic subdural hematoma of the convexity is considered together with both surgical and medical therapeutic indications.
Subject(s)
Hematoma, Subdural/surgery , Accidental Falls , Aged , Hematoma, Subdural/diagnosis , Hematoma, Subdural/diagnostic imaging , Humans , Male , Tomography, X-Ray ComputedABSTRACT
A case of multiformis glioblastoma with a parieto-temporal and brainstem localization is presented. Multicentric gliomas are unfrequently reported in the literature, and very often rise diagnostic problems with other multiple lesions of the Central Nervous System, either of neoplastic nature or not. After briefly reviewing the pathogenetic hypothesis concerning this lesion, indication and limits of clinical and radiological investigations are discussed.
