Current overview of structural magnetic resonance imaging in schizophrenia

Non-invasive morphologic imaging (computer tomography, magnetic resonance imaging, MRT) has contributed significantly to our understanding of schizophrenic disorders as diseases of the brain. Improved MRT techniques enable us to analyse anatomical substructures. The present overview evaluates peer-reviewed MRT studies published between 1994 and July 2000 and provides a comparison with our own results. Chronic schizophrenic patients most frequently show an enlargement in the ventricular system along with a reduction in grey matter. A more detailed subdivision into cortical and subcortical regions additionally shows the noted volume reduction to be limited to specific areas within the brain rather than being distributed equally throughout the brain. Within the area of the temporal lobes the two most frequently affected areas are the hippocampus and the gyrus temporalis superior. Alterations within these areas correlate with clinical symptoms such as hallucinations or thought disorders. Within the frontal cortex nearly 70% of all studies show a decrease in overall volume, while 63% note a reduction in size within the thalamus and 60% in the cerebellum. Morphologically speaking these structures therefore play the greatest role in the pathophysiology of schizophrenia and the onset of clinical symptoms. More recent studies also showed a specific progression in subgroups of patients pointing toward a neurodegenerative process. Additionally there are a number of differential antipsychotic effects following longterm treatment with typical neuroleptics as compared to atypical antipsychotics. Based on these findings future longitudinal studies should examine to what extent such a progressive decrease in volume might be influenced by treatment with modern antipsychotics.     

Adjuvante Wirkung von EMLA®-Creme bei der Oberlidblepharoplastik

BACKGROUND: The injection of local anesthesia before upper lid blepharoplasty is perceived as unpleasant and painful by some patients. METHODS: In an intraindividual randomized prospective study, 14 patients undergoing upper lid blepharoplasty on both sides were examined. Before the operation the EMLA creme was put on one side. The pain sensibility was checked before and after using EMLA creme and during the infiltration of anesthesia and the operation. RESULTS: The sensitivity before putting on EMLA creme was equal in all patients on both sides. After application there was a distinct difference between the sides. During the infiltration of anesthesia 12 patients reported low and 2 patients medium pain on the treated side, while on the non-treated side 5 patients reported low, 4 patients medium, and 5 patients severe pain. CONCLUSIONS: Applying EMLA creme before an operation reduces the pain sensitivity during infiltration of anesthesia and during the operation.     

Molecular genetic analysis of the BIGH3 gene in lattice type I (Biber-Haab-Dimmer) and granular type II (Avellino) corneal dystrophy: is indirect mutation analysis for hot spots recommended?

BACKGROUND: Mutations of the BIGH3 gene were delineated as the underlying gene defect for corneal dystrophy Lattice Type I (CDL1) and corneal dystrophy Avellino type (CDA) in families with different regional provenance. Missense mutations in exon 4 with single base pair substitution which result in amino acid alterations Arg124Cys (CDL1) and ARG124His are described as hot spots. We report on histopathological and molecular genetic investigations in 2 German families and a single patient with CDL1 and CDA. METHOD: In 3 affected family members and 1 unaffected family member and in one single patient with CDL1 and in 3 affected family members and 1 unaffected family member of a family with CDA mutation analysis in exon 4 of BIGH3 gene by direct sequencing of genomic DNA from peripheral blood was performed. Histopathological examination of corneal tissue of both index patients was performed after penetrating keratoplasty. RESULTS: We revealed a heterozygous single base pair substitution 417C-->T in family A and patient B (CDL1) and a heterozygous single base pair substitution 418G-->A in family C (CDA). In all index patient's diagnosis was confirmed by histopathological examination of corneal tissue. The sequencing results were confirmed by restriction digestion with HpyCH4V (NEB; CDL1) restriction endonuclease site and AvaII (NEB; CDA) restriction endonuclease site. The heterozygous 417C-->T transition in family A and patient B alters the amino acid sequence from Arg124Cys while the heterozygous 418G-->A transition in family C alters the amino acid sequence from Arg124His in the keratoepithelin. COMMENT: Codon 124 of the BIGH3 gene appears as a mutation hot spot also in German families with CDL1 and CDA. Indirect mutation analysis with restriction digestion is suggested as first step investigation in families with relevant corneal dystrophies. Direct sequencing of all exons is recommended as a second step if there are no results in restriction digestion.     

Sensory information processing in neuroleptic-naive first-episode schizophrenic patients: a functional magnetic resonance imaging study

BACKGROUND: Schizophrenic disorders are thought to involve widespread abnormalities in information processing. The present study used functional magnetic resonance imaging and a simple and robust paradigm that involved auditory and visual activation to examine basic sensory input circuits. Our aim was to determine which stages of the input processing network are disturbed in first-episode schizophrenic patients. METHODS: Twelve neuroleptic-naive inpatients (paranoid subtype) were compared with 11 healthy subjects by means of echo-planar functional magnetic resonance imaging. In a block design, the paradigm included the simultaneous presentation of a moving 6-Hz checkerboard and auditory stimuli in the form of drumbeats. The subjects were asked to simply look and listen. RESULTS: In comparison with control subjects, patients showed reduced activation in the right thalamus, the right prefrontal cortex, and the parietal lobe (restricted to the dorsal visual pathway) bilaterally. There were no notable differences in the primary visual cortex or the object-specific occipitotemporal pathway. In addition, patients presented with a reduced signal change to auditory stimulation in the left acoustic cortex. CONCLUSIONS: The present study supports the concept of widespread cortical and subcortical deficits in schizophrenia. Our findings suggest abnormal functioning early in the information processing and in high-order association cortices already at illness onset, before the administration of medication or the most confounding effects of illness duration. The main regions have been implicated in visual motion perception and discrimination as well as in attention to sensorial events and perceptual synthesis.     

Clinical diagnosis of chronic canaliculitis by 20-MHz ultrasound

The practical value of high-resolution ultrasound (transducer frequency of 20 MHz) in the study of the lacrimal canaliculi has been proven. It can also be used in the clinical diagnosis of chronic canaliculitis. If the classic symptoms are absent, the clinical diagnosis is often inaccurate, and treatment is insufficient. Representative images of normal cases and of chronic canaliculitis illustrate the potential of high-resolution ultrasound. In our patient, 20-MHz scanner images revealed pathological findings which were invisible during slitlamp examination. Ultrasonic images of chronic canaliculitis showed ectasia of the canaliculus and sulfur grains. High-resolution ultrasonic examination of the lacrimal drainage system demonstrated that the 20-MHz scanner used was able to show concrements (sulfur grains), measuring 1-2 mm in diameter. Such more reflective structures (like sulfur grains) are a pathognomonic sign of chronic canaliculitis. Our report confirms the efficiency of 20-MHz sonography in the diagnosis of canaliculitis without any side effects.     

Synthesis and release of platelet-activating factor and eicosanoids in human endothelial cells induced by different agonists

Production of platelet-activating factor (PAF) and eicosanoids by human umbilical vein endothelial cells (HUVEC) after stimulation with different agonists has been studied. Significant amounts of PAF were measured in the cellular fraction after treatment with thrombin (2 NIHu/ml), calcium ionophore A23187 (2 M) and histamine (100 M) (110.3±14.3, 80.7±19.2 and 119.2±22.4 pg/10⁵ cells, respectively). Only thrombin caused a partial release of PAF into the supernatant. IL-1 (0.1 nM), TNF (1 nM), arachidonic acid (10 M) and endothelin (0.1 M) were not able to induce any PAF synthesis. High levels of 6-keto-PGF₁ were found after stimulation with thrombin and calcium ionophore A23187 (8641±2575 and 6715±3340 pg/10⁵ cells, respectively). Cytokines IL-1 and TNF were also able to stimulate PGI₂ synthesis, although to a lesser extent. PGE₂ production increased after treatment with thrombin and calcium ionophore A23187 three- and two-fold, respectively. Our results confirm that stimulated HUVEC are able to synthesize PAF and eicosanoids simultaneously, the relative amounts depending upon the agonist used. None of the agonists studied showed any significant effect on 15-HETE production.     

The control of sodium excretion following saline infusion in dogs

Summary The increase in fractional excretion of sodium following intravenous infusion of saline has been investigated in dogs fed with sodium-rich or poor diets after transplantation to the neck of these animals of kidneys removed from dogs submitted previously to either diet. The response of in situ and of transplanted organs has been compared in the four possible combinations of perfusors and kidney donors. No significant differences were observed between the four series, for the same net saline load, in arterial and venous pressures, extravascular and intravascular expansion, or blood dilution. The response in each series was independent of extracellular expansion and was best related to the degree of blood dilution. However, the magnitude of the response to the same net saline load depended on a resetting of the sensitivity of the kidney itself to the blood changes, this resetting depending on the previous dietary sodium balance. This sensitivity was related also to the presence in the blood of a potentiating material which might be, at least partly, of renal origin, and which might represent an intrarenal mediator of the natriuretic response.This work has been performed with the help of the Fonds National de la Recherche Scientifique of Belgium.