ABSTRACT
A proposal that an endogenous benzodiazepine-like agent named endozepine-4 might be responsible for presentations of recurrent stupor has gained wide acceptance. A case of recurrent stupor over two decades is presented with many similarities to previous cases of "endozepine stupor". This case, however, was caused by exogenous benzodiazepine administration and serves as a warning to clinicians to beware of this diagnosis.
Subject(s)
Coma/chemically induced , Lorazepam/poisoning , Oxazepam/poisoning , Aged , Crime , Humans , Lorazepam/administration & dosage , Male , Oxazepam/administration & dosage , Periodicity , Poisoning/diagnosis , SpousesABSTRACT
Although rare, direct infiltration of the cauda equina by non-Hodgkin's lymphoma (NHL) must be considered as a potential cause of subacute onset paraplegia. We present two cases of lymphomatous involvement of the cauda equina presenting with subacute paraplegia, each associated with a palsy of an oculomotor nerve. We highlight the need to use gadolinium-enhanced magnetic resonance imaging (MRI) when investigating potential cauda equina lesions, since it is crucial in detecting and outlining the extent of disease. Differential diagnoses and treatment options for NHL involving the cauda equina are also discussed.
Subject(s)
Cauda Equina/pathology , Lymphoma, Non-Hodgkin/pathology , Neoplasm Invasiveness/pathology , Oculomotor Nerve Diseases/etiology , Polyradiculopathy/pathology , Spinal Neoplasms/pathology , Abducens Nerve Diseases/etiology , Aged , Antineoplastic Agents/therapeutic use , Cauda Equina/physiopathology , Contrast Media , Fatal Outcome , Female , Gadolinium , Humans , Lymphoma, Non-Hodgkin/complications , Lymphoma, Non-Hodgkin/physiopathology , Magnetic Resonance Imaging/methods , Male , Neoplasm Invasiveness/physiopathology , Neoplasm Recurrence, Local , Pain/etiology , Paraparesis/etiology , Paraplegia/etiology , Polyradiculopathy/etiology , Polyradiculopathy/physiopathology , Skull Neoplasms/pathology , Spinal Neoplasms/complications , Spinal Neoplasms/physiopathology , Steroids/therapeutic use , Thoracic Vertebrae/pathology , Treatment FailureSubject(s)
Adenoma/complications , Cushing Syndrome/etiology , Pituitary Neoplasms/complications , Adenoma/diagnosis , Adenoma/therapy , Antineoplastic Agents, Hormonal/therapeutic use , Cushing Syndrome/diagnosis , Cushing Syndrome/therapy , Diagnosis, Differential , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Pituitary Neoplasms/diagnosis , Pituitary Neoplasms/therapy , Vision Disorders/etiology , Weight GainABSTRACT
Recent neuroimaging studies have provided evidence for localized perceptual specificity in the processing of human voice stimuli, paralleling the specificity for human faces. This study attempted to delineate the perceptual features of human voices yielding selective processing, and to characterize its time-course. Electrophysiological recordings revealed a positive potential peaking at 320 ms post-stimulus onset, in response to sung tones compared with fundamental-frequency-matched instrumental tones, when both categories were distracters in an oddball task. This voice-specific response (VSR) evoked under conditions different from those yielding positivity at that latency in other contexts, indicates the overriding salience of voice stimuli, possibly reflecting the operation of a gating system directing voice stimuli to be processed differently from other acoustic stimuli.
Subject(s)
Speech Perception/physiology , Acoustic Stimulation/methods , Adolescent , Adult , Analysis of Variance , Auditory Pathways/physiology , Brain Mapping , Electroencephalography , Electrooculography , Electrophysiology , Evoked Potentials, Auditory/physiology , Female , Humans , Male , Music , Reaction Time/physiologyABSTRACT
People who have the ability to label or to produce notes without any reference are considered to possess Absolute Pitch (AP). Others, who need a reference in order to identify the notes, possess Relative Pitch (RP). The AP ability is assumed to reflect a unique, language-like representation of non-lexical musical notes in memory. The purpose of this study was to examine this assumption by comparing Event Related Potentials (ERP) of musicians with and without AP, to lexical and non-lexical representation of musical material. Subjects were eighteen young adult musicians. Seven were AP and eleven RP. Auditory stimuli, presented through earphones, were piano notes (non-lexical) or a voice saying the note's name (lexical). Visual stimuli, presented on a computer display were note symbols (non-lexical) or letters (lexical). Subjects performed a number of tasks, combining the two modalities (visual and auditory) and stimulus types (lexical and non-lexical), and reaction times (RT), performance accuracy and evoked potentials were recorded. The tasks forced the subjects to transfer mental representations of musical material from one mode to another. Our most important findings were the differences, between groups, in the scalp distribution of P300 amplitudes. We conclude that absolute pitch possessors use the same internal language as relative pitch possessors, when possible, but the distribution of the underlying brain activity is different between AP and RP subjects.
Subject(s)
Electroencephalography , Evoked Potentials, Auditory/physiology , Evoked Potentials, Visual/physiology , Hearing/physiology , Acoustic Stimulation , Adolescent , Adult , Discrimination, Psychological/physiology , Humans , Memory, Short-Term/physiology , Music , Photic Stimulation , Reaction Time/physiologyABSTRACT
Urease was bound to commercially available nonwoven nylon fabric filters. Multilayer immobilized-enzyme filter reactors were constructed by packing varying numbers of urease-nylon filters in a column. Owing to the relatively open structure and high mechanical strength of the filter fabric, compaction and pressure drop effects were minimal. The reactors could be operated in a wide range of substrate concentrations and flow rates under conditions where mass-transfer limitations could be neglected. The kinetic behavior of the immobilized-enzyme filter reactors could be described by a linear form of the integrated Michaelis-Menten equation using a model based on the sequential action of the enzyme filters.
