Elevation of extracellular cortical noradrenaline may contribute to the antidepressant activity of zotepine: an in vivo microdialysis study in freely moving rats.

The antipsychotic, zotepine, as well as possessing affinity for dopamine D1- and D2-1ike receptors, has high affinity for the noradrenaline (NA) transporter and inhibits [3H]NA uptake by rat frontal cortex synaptosomes, in vitro. The present studies investigated the effects of zotepine on extracellular NA in the frontal cortex of freely moving rats using in vivo microdialysis. Removal of calcium from the perfusate reduced extracellular NA by 70.

Somatosensory cortex: a comparison of the response to noxious thermal, mechanical, and electrical stimuli using functional magnetic resonance imaging.

In the present study, functional magnetic resonance imaging (fMRI) was used to examine pain perception in humans. Three types of noxious stimuli were presented: electric shock (20.8 mA, 2 Hz), heat (48 degrees C), and mechanical, as well as a control tactile stimulus.

Magnetoencephalography and magnetic source imaging.

Current brain imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI), provide noninvasive, high-resolution images that depict fine anatomic structure and delineate pathology by control of image contrast and sensitivity to the physicochemical microenvironment. These methods, although invaluable for the identification, characterization, and localization of lesions, do not provide any assessment of the functional viability of brain tissues, nor of the spatial organization of sensory, motor, and cognitive systems. However, such additional functional information is of great significance to the clinician in the determination of treatment strategies and patient management.

Peri-threshold encoding of stimulus frequency and intensity in the M100 latency.

Recent work has suggested that, in addition to spatial tonotopy, pitch and timbre information may be encoded in the temporal activity of the auditory cortex. Specifically, the post-stimulus latency of the maximal cortical evoked neuromagnetic field (M100 or N1m) is a function of stimulus frequency. We investigated the additional effect of varying the stimulus intensity on the M100 response.

p53 protein expression in tumours from head and neck subsites, larynx and hypopharynx, and differences in relationship to survival.

The present study involves an immunohistochemical analysis of p53 protein expression in head and neck tumours located at two separate subsites, the larynx and hypopharynx. It attempts to relate differences in expression to differences in the behaviour of these tumours. Detection of the p53 protein was performed using immunohistochemistry on 32 specimens of hypopharyngeal squamous cell carcinoma and 35 specimens of laryngeal squamous cell carcinoma.

Imaging patterns of neonatal hypoglycemia.

Purpose: Our purpose was to report the patterns of injury observed in five patients who suffered brain damage consequent to neonatal hypoglycemia.

Methods: The imaging studies and clinical records of five patients with brain damage caused by neonatal hypoglycemia were reviewed retrospectively. Patterns of injury were compared with those described in the literature and those seen in neonatal hypoxic-ischemic injury.

p53 expression and p53 gene mutation in oral cancer and dysplasia.

Background: The aim of the current study was to examine the possible association of the p53 tumor suppressor gene with the development of oral cancer. We examined biopsy material from patients with oral squamous cell carcinoma for p53 protein expression and p53 mutations.

Methods: Eighteen samples were analyzed.

PROACT: a phase II randomized trial of recombinant pro-urokinase by direct arterial delivery in acute middle cerebral artery stroke. PROACT Investigators. Prolyse in Acute Cerebral Thromboembolism.

Background And Purpose: To test the safety and recanalization efficacy of intra-arterial local delivery of plasminogen activators in acute ischemic stroke, a randomized trial of recombinant pro-urokinase (rpro-UK) versus placebo was undertaken in patients with angiographically documented proximal middle cerebral artery occlusion.

Methods: After exclusion of intracranial hemorrhage by CT scan, patients with abrupt onset of symptoms of focal ischemia likely to receive treatment within 6 hours who satisfied all clinical eligibility criteria underwent carotid angiography. Patients displaying Thrombolysis in Acute Myocardial Infarction grade 0 or 1 occlusion of the M1 or M2 middle cerebral artery were randomized 2:1 to receive rpro-UK (6 mg) or placebo over 120 minutes into the proximal thrombus face.

Adenoid cystic carcinoma of the head and neck.

Adenoid cystic carcinoma has a long natural history but frequently proves fatal. The present study describes 108 patients with an adenoid cystic carcinoma of the head and neck seen over a 30-year period. Analysis of the data utilized both univariate and multivariate methods.

Presurgical multimodality neuroimaging in electroencephalographic lateralized temporal lobe epilepsy.

The purpose of this study was to compare 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET), hippocampal volumetry (HV), T2 relaxometry, and proton magnetic resonance spectroscopic imaging (1H-MRSI) in the presurgical neuroimaging lateralization of patients with nonlesional, electroencephalogram (EEG)-defined unilateral temporal lobe epilepsy (TLE). Twenty-five patients were prospectively studied, along with age-matched controls. T2 relaxometry examinations were performed in 13 patients.

Generalised seizure-induced changes in rat hippocampal glutamate but not GABA release are potentiated by repeated seizures.

The effects of repeated or a single generalised seizure on extracellular glutamate and gamma-aminobutyric acid (GABA) levels in the ventral hippocampus of the freely-moving rat were studied using maximal electroshock-induced seizures in conjunction with in vivo microdialysis. A single seizure resulted in three phases of post-ictal changes in glutamate and GABA levels: during phase I, there were transient increases in both glutamate and GABA whilst in phase II, levels of both amino acids were reduced. In phase III, glutamate levels were elevated above basal whilst the decrease in GABA levels was sustained.

Magnetoencephalography in partial epilepsy: clinical yield and localization accuracy.

The goals of this study were to determine (1) the yield of magnetoencephalography (MEG) according to epilepsy type, (2) if MEG spike sources colocalize with focal epileptogenic pathology, and (3) if MEG can identify the epileptogenic zone when scalp ictal electroencephalogram (EEG) or magnetic resonance imaging (MRI) fail to localize it. Twenty-two patients with mesial temporal (10 patients), neocortical temporal (3 patients), and extratemporal lobe epilepsy (9 patients) were studied. A 37-channel biomagnetometer was used for simultaneously recording MEG with EEG.

Learning transfer and neuronal plasticity in humans trained in tactile discrimination.

Adult humans were unilaterally trained in a tactile discrimination task of sequentially applied multi-finger stimuli. Magnetic source imaging (MSI) was performed before and after the training to evaluate use-dependent neuronal plasticity. All subjects showed fast improvements in performance and complete transfer of the learned task.

Magnetic source imaging as a tool for presurgical functional brain mapping.

This article describes magnetic source imaging, a newly-developing technology which can be used to noninvasively map eloquent cortex prior to surgical procedures. It is based on large-array detection of extracranial magnetic fields arising from neuronal currents evoked by peripheral stimulation. A range of evoked and spontaneous neuromagnetic activities are discussed along with clinical examples of the utility of the technique and comparison to other brain mapping techniques, such as positron emission tomography, functional magnetic resonance imaging, EEG, and ECoG.

Mapping of the sensorimotor cortex: functional MR and magnetic source imaging.

Purpose: To assess the reliability and comparability of functional MR imaging and magnetic source imaging for mapping the somatosensory cortex.

Methods: Parallel studies were performed in eight volunteer subjects in whom both hemispheres were measured with the use of painless tactile stimulation of the tip of each index finger. Magnetic source imaging was performed using a 37-channel biomagnetometer; evoked magnetic fields were analyzed using the single-equivalent dipole representation to ascertain the neuronal source.

An immunohistochemical analysis of p53 protein expression in pre-malignant and malignant tissues of the oral cavity.

This study looks at p53 protein expression in dysplastic and malignant lesions of the oral cavity using an immunohistochemical staining technique. Archival biopsy specimens of oral dysplasia of squamous cell carcinoma from 64 patients were analysed immunohistochemically. Sections from 90 oral biopsy specimens were examined in all.

Processing of vowels in supratemporal auditory cortex.

The auditory evoked neuromagnetic fields elicited by synthesized vowels of two different fundamental frequencies F0 were recorded in six subjects over the left and right temporal cortices using a 37-channel biomagnetometer. Single equivalent current dipole modeling of the fields elicited by all vowel types localized activity to a well-circumscribed area in supratemporal auditory cortex in both hemispheres. There were hemisphere asymmetries in the amplitude and latency of the M100 response.

Sensory mapping in a congenitally deaf subject: MEG and fRMI studies of cross-modal non-plasticity.

It has been proposed that the auditory cortex of deaf subjects may provide an example of cross-modal compensatory plasticity. We investigated whether sensory stimulation could elicit responses from auditory areas of a congenitally deaf subject. Neuromagnetic fields were recorded using a 37-channel biomagnetometer under conditions of: 1) visual stimulation; 2) somatosensory stimulation; and 3) a simple motor task.

Task-induced asymmetry of the auditory evoked M100 neuromagnetic field elicited by speech sounds.

The auditory evoked neuromagnetic fields elicited by synthesized speech sounds (consonant-vowel syllables) were recorded in six subjects over the left and right temporal cortices using a 37-channel SQUID-based magnetometer. The latencies and amplitudes of the peaks of the M100 evoked responses were bilaterally symmetric for passively presented stimuli. In contrast, when subjects were asked to discriminate among the same syllabic stimuli, the amplitude of the M100 increased in the left and decreased in the right temporal cortices.

MIB-1 and involucrin expression in laryngeal squamous carcinoma: the relationship to host and tumour factors and survival.

MIB-1 is an antibody which attaches to the Ki67 antigen expressed by proliferating cells. MIB-1 immunoreactivity may be used to quantify the proliferative component of a tumour. Involucrin is a protein expressed by mature keratinocytes and may be used as a marker of differentiation.

Noninvasive somatosensory monitoring of the injured inferior alveolar nerve using magnetic source imaging.

Purpose: This study evaluates magnetoencephalography (MEG) as an objective monitor for the evaluation of post-traumatic inferior alveolar nerve injuries.

Materials And Methods: Six patients with unilateral inferior alveolar nerve injuries were assessed using conventional sensory examination techniques. All damaged nerves, and their contralateral controls, were then reexamined using MEG technology.