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Biomedical subjects

A Falini

Publications and source records attributed to A Falini.

At least 37 records · Page 2Linked to original sources

Progressive brain failure after diffuse hypoxic ischemic brain injury: a serial MR and proton MR spectroscopic study.

The findings at sequential MR imaging and proton MR spectroscopy of a patient with profound hypoxic-ischemic brain injury are reported. The pattern of structural and biochemical changes observed closely reflected the known evolution of postasphyxic brain degeneration. Particularly noteworthy were the sharp decrease of cortical N-acetylaspartate in the acute phase, suggesting the severity of the neuronal insult, and the subsequent progressive increase of choline, paralleling the delayed degeneration of white matter.

Adult↗

The use of magnetic resonance spectroscopy in the evaluation of the natural history of multiple sclerosis.

Magnetic resonance spectroscopic imaging (MRSI) can be used to define specific chemical-pathological changes in the brain of patients with multiple sclerosis. Magnetic resonance spectroscopy offers promise for improved definition of the nature of individual lesions, the dynamics of their evolution, their effects on normal appearing white matter, and their relation to clinical disability. Combined multimodal MRSI studies of the brains of patients with multiple sclerosis therefore soon may provide efficient, specific, and quantitative new approaches to assessment of drug effects in therapeutic trials.

Axons↗

Cerebral involvement in celiac disease: a serial MRI study in a patient with brainstem and cerebellar symptoms.

A patient with celiac disease and relapsing-progressive symptoms suggesting brainstem and cerebellar involvement underwent serial MRIs. The first examination revealed multiple enhancing and nonenhancing lesions. Thereafter, a large enhancing cerebellar lesion appeared, followed by severe cerebellar atrophy. The presence of structural neuronal damage was confirmed by proton MR spectroscopy and magnetization transfer imaging. MRI results and CSF findings suggested that neurologic complications were more likely due to an inflammatory process.

Adult↗

Proton magnetic resonance spectroscopy and intracranial tumours: clinical perspectives.

Proton magnetic resonance spectroscopy (1H-MRS) was applied to characterize intracranial tumours of different hystological types. Seventy patients with intracranial neoplasms were studied before receiving surgery, radiotherapy or chemotherapy. All tumours were characterized by reduced or absent N-acetylasparate and increased signal from choline-containing compounds. Distinctive patterns were observed only for primitive brain neoplasms; high-grade gliomas were differentiated from low-grade ones by higher levels of choline-containing compounds. The metabolic aspects of metastatic lesions were similar to high-grade gliomas. These results, together with the limitations of 1H-MRS and future applications are reviewed.

Adenoma↗

Proton magnetic resonance spectroscopy in patients with glial tumors: a multicenter study.

The authors represent a cooperative group of 15 institutions that examined the feasibility of using metabolic features observed in vivo with 1H-magnetic resonance (MR) spectroscopy to characterize brain tumors of the glial type. The institutions provided blinded, centralized MR spectroscopy data processing long with independent central review of MR spectroscopy voxel placement, composition and contamination by brain, histopathological typing using current World Health Organization criteria, and clinical data. Proton 1H-MR spectroscopy was performed using a spin-echo technique to obtain spectra from 8-cc voxels in the tumor and when feasible in the contralateral brain. Eighty-six cases were assessable, 41 of which had contralateral brain spectra. Glial tumors had significantly elevated intensities of choline signals, decreased intensities of creatine signals, and decreased intensities of N-acetylaspartate compared to brain. Choline signal intensities were highest in astrocytomas and anaplastic astrocytomas, and creatine signal intensities were lowest in glioblastomas. However, whether expressed relative to brain or as intratumoral ratios, these metabolic characteristics exhibited large variations within each subtype of glial tumor. The resulting overlaps precluded diagnostic accuracy in the distinction of low-and high-grade tumors. Although the extent of contamination of the 1H-MR spectroscopy voxel by brain had a marked effect on metabolite concentrations and ratios, selection of cases with minimal contamination did not reduce these overlaps. Thus, each type and grade of tumor is a metabolically hetero-geneous group. Lactate occurred infrequently and in all grades. Mobile lipids, on the other hand, occurred in 41% of high-grade tumors with higher mean amounts found in glioblastomas. This result, coupled with the recent demonstration that intratumoral mobile lipids correlate with microscopic tumor cell necrosis, leads to the hypothesis that mobile lipids observed in vivo in 1H-MR spectroscopy may correlate independently with prognosis of individual patients.

Adolescent↗

Imaging of tumors of the central nervous system.

Research in diagnosing and understanding brain tumors in neuroradiology is influenced by the investigative tools available to neuroradiologists. CT has represented the gold standard for the past two decades. The role of angiography has become complementary; relevant in the therapeutic phase of embolization of meningiomas or base of the skull tumors or in intra-arterial chemotherapy for gliomas. In 1991, the MR imaging revolution continues to provide new insights in the diagnosis, classification, and understanding of the biology of brain tumors. Interest has been focused mainly on information provided by MR imaging and MR spectroscopy. Spectroscopy is being used in a more systematic way and in large series with different histologic tumor types. Spectra from tumors are definitely different from those of normal brain, although no specific patterns for histologic types were found, with the possible exception of meningiomas. Comparison with positron emission tomography is considered to be useful. Analysis of rare tumors using MR imaging allows better understanding, classification, diagnosis, and surgical therapy of lesions such as central neurocytomas, hamartomatous tumors, and lymphomas. An attempt at a better classification for brain tumors was proposed and may prove to be very useful for systematization and communication.

Acquired Immunodeficiency Syndrome↗

Human fetal brain beta-nerve growth factor cDNA: molecular cloning of 5' and 3' untranslated regions.

The mRNA of beta-nerve growth factor (beta-NGF) has been demonstrated to be present in the human brain, both in adult and fetal stages of development. However, its complete nucleotide sequence is unknown since a full-length cDNA has yet to be isolated. We report here the cloning and complete analysis of the human fetal brain beta-NGF transcript. cDNA synthesis was performed from total brain RNA and overlapping regions of beta-NGF cDNA were enzymatically amplified and sequenced. The central portion of the cDNA was amplified using primers designed on the known genomic DNA sequence. The 5' and 3' unknown regions were amplified by the anchored polymerase chain reaction (PCR) and by complementary DNA Ends-PCR respectively. The latter method is an original variation of Inverted PCR. The sequenced transcript is very similar to the most common form of beta-NGF mRNA present in the mouse central nervous system. In addition, both the 5' and 3' untranslated regions show a high degree of homology to the corresponding murine sequences.

Base Sequence↗

Beta-nerve growth factor (beta-NGF) mRNA expression in the parkinsonian adrenal gland.

The adrenal gland is a well-demonstrated source for different neurotrophic factors. The presence of the beta-nerve growth factor (beta-NGF) mRNA in the adrenal tissue used for grafting in a Parkinsonian patient is reported here. Adrenal samples were obtained on the day of implantation, and a specific cDNA was synthesized after the extraction of total RNA using a synthetic oligonucleotide as a reverse transcription primer. A 168-bp portion of the cDNA was amplified using two other oligonucleotides as Taq polymerase primers in a polymerase chain reaction. Thirty-two cycles of amplification were performed. The amplification products were identified by agarose gel electrophoresis and Southern blot analysis as a single DNA band hybridizing with a third beta-NGF specific oligonucleotide. The identity of the fragment was confirmed by DNA sequencing. Quantitative analysis demonstrated a beta-NGF mRNA concentration exceeding 5 fg/micrograms of total adrenal RNA. These findings add NGF to the other neurotrophic factors produced by the gland (i.e., basic fibroblast growth factor) and demonstrate the retained functional capacity of the Parkinsonian adrenal to express the beta-NGF mRNA. All these data may assume relevant meaning for neurotransplantation research.

Adrenal Glands↗

Detection of beta-nerve growth factor mRNA in the human fetal brain.

Nerve growth factor (NGF) is a trophic molecule recently demonstrated to interact with different structures in the central nervous system. The expression of the beta-NGF mRNA from human fetal cortices at the 15-16th week of gestational age has been demonstrated and quantitated by polymerase chain reaction amplification of the specific cDNA. beta-NGF mRNA expression in the human brain coincides with the period of active differentiation and synaptogenesis, suggesting that the trophic agent plays a role in the cerebral development.

Base Sequence↗

Human neuronal cells in culture: from concepts to basic methodology.

The paper reviews some conceptual and methodological aspects of the tissue culture models which, during the past three decades, demonstrated a remarkable mimicry of many important structures and functions of the mammalian Central Nervous System (CNS) and related peripheral sensory and motor elements. Emphasis is placed on an original human neuronal tissue culture model obtained from selective CNS areas. The different cell types were identified and the neurotrophic interactions preliminary characterized. Neuropathological findings suggest hypothesis that can be fully tested using in vitro human models of affected cerebral specific areas.

Brain↗

Human neuronal cell viability demonstrated in culture after cryopreservation.

A human neuronal cell freezing technique has been developed. The results indicate that human fetal neuronal cells can be frozen with 7%-10% dimethyl sulfoxide (DMSO) as cryoprotectant. The survival of isolated thawed cells has been evaluated in culture. Cells have been frozen at -196 degrees C for 370 days without loss of viability. Average recovery rate of frozen cells was 62% of the recovery rate of cultured unfrozen controls. Thawed cells show neurite outgrowth and maintain both cellular markers such as neuron specific enolase (NSE) and neurochemical characteristics (GABA synthesis). Morphological integrity of cryopreserved neurons has been confirmed at ultrastructural level.

Cell Survival↗

Cryopreservation of human fetal adrenal medullary cells.

Cryopreservation of human fetal adrenomedullary cells was performed, after dissociation of the gland and purification of chromaffin aggregates, using 10% dymethyl sulfoxide as cryoprotectant. More than 90% of thawed cultured clusters appear morphologically intact, showing extensive neurite outgrowth and absence of appreciable cellular loss. Immunoreactivity for tyrosine hydroxylase and response to nerve growth factor were demonstrated. These findings indicate that human medullary cells maintain their distinctive functional characteristics after cryopreservation.

Adrenal Medulla↗

Primary cultures of human caudate nucleus.

It is possible to grow functional primary dissociated cultures and explants from stereotactic biopsies of human parkinsonian caudate nuclei. Two major classes of cells were identified on morphological grounds. The culture cells appear to be stimulated by an unidentified soluble factor(s) obtained from human fetal neuronal cells in vitro. Culture of primary neuronal and glial cells from human adult cerebral nuclei seems to be a useful tool for several research purposes and in particular for studying both trophic factor action and target effects on afferent neurons for prospective human brain grafting.

Adult↗