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We report two cases of patients with bilateral 'mirror image' or 'kissing' aneurysms at the distal anterior cerebral arteries who presented with subarachnoid haemorrhage and frontal intracerebral haematoma.
Comparison of cDNA libraries derived from the spinal cord with those derived from the visual cortex by means of forward and reverse subtractive hybridization resulted in the cataloguing of 60 genes differentially expressed in the spinal cord. 1. The differentially expressed genes represent a mixture of novel and known sequences with known and unknown protein products. 2. The possibility that the subtraction process was simply overwhelmed by background sequences was significantly reduced by several observations including comparisons between suppression subtractive hybridization (SSH) and mirror orientation selection (MOS). 3. Nearly half of all genes up-regulated in the spinal cord are of myelin origin. 4. Twenty-five percent of all up-regulated clones in the spinal cord versus the visual cortex are for proteolipid protein. 5. Ten percent of all up-regulated clones in spinal cord versus visual cortex are for ferretin heavy chain, which is known to be produced in oligodendroglial cells in the CNS. 6. Two of the up-regulated sequences, proteolipid protein and N-myc down-regulated gene 4, are identified with genes known to directly affect neuron survival. 7. Two of the up-regulated genes, ferritin and transferrin, are indirectly associated with apoptosis through their ability to sequester iron and reduce free radical formation.
A mirror is the ideal fixation device for an ophthalmoscopic examination: it is the essense of simplicity, and there is nothing the patient would rather watch than himself.
Submicroscopic changes of neurons, synapses, glial cells and some elements of capillaries were established by studying chronic mirror foci which appeared in the rat cerebral cortex after implantation of cobalt-gelatinous rods into the contralateral hemisphere. The results were compared with normal control cortex and with changes after thermocoagulation of the symmetrical contralateral cortex. It is shown that epileptogenic lesions produce a significant reduction of RNA-components, edema and vacuolization of neuronal cytoplasm, hypertrophy and proliferation of glial cells. The revealed pathological changes of the synapses were manifested by dilatation of some vesicles and the appearance of heterogenic inclusions. The characteristic features of Wallerian degeneration of callosal synapses and the reversible retrograde changes of the neurons which send their axons into the traumatized zone of the contralateral hemisphere were observed to be similar after both experimental lesions.
Golgi-impregnated 'starburst' amacrine cells share significant morphological features with cholinergic neurons in rabbit retina. They are mirror-symmetrical about the a/b (OFF/ON) sublaminar border of the inner plexiform layer. Type a starburst amacrines have cell bodies in the amacrine cell layer and dendrites in sublamina a, while type b cells have their cell bodies in the ganglion cell layer and dendrites in sublamina b of the inner plexiform layer (IPL). The two levels of narrow dendritic stratification are precisely those demonstrated by Masland and Mills for cholinergic amacrine cells. The morphological evidence indicates that the duality of ON and OFF pathways is served separately by type b (displaced) and type a starburst amacrine cells, respectively.
The 'mirror technique' was applied in immunoelectron microscopy to demonstrate the synaptic relationship between neuronal structures containing catecholamines and substance P in the caudal part of nucleus of the solitary tract in the rat, using antisera against tyrosine hydroxylase and substance P. Substance P-immunoreactive axon terminals were shown to make two types of synaptic contacts (asymmetrical and symmetrical) with catecholaminergic neurons. It is concluded that substance P afferents can directly affect catecholaminergic neurons in this nucleus via synapses.
The 'mirror technique' was used in immuno-electron microscopy to examine the synaptic relationships between neuronal structures containing catecholamines and cholecystokinin (CCK) in the caudal part of the dorsomedial medulla oblongata in the rat, using antisera against tyrosine hydroxylase and CCK. CCK-immunoreactive axon terminals made synaptic contacts with catecholaminergic neurons. Some of these catecholaminergic neurons contained CCK.
A direct synaptic contact between nigrostriatal dopamine neurons and substance P axons in the substantia nigra was demonstrated using the immunoelectron microscopic mirror technique combined with the fluorescent double-staining method for transmitter-specific projections. Substance P-immunoreactive terminals were found to make synaptic contact with nigral cells exhibiting tyrosine hydroxylase immunoreactivity and retrograde fluorescent labeling following injection of biotinylated lectin into the neostriatum. It appears that substance P afferents directly affect nigrostriatal dopamine neurons in the substantia nigra via the synaptic contacts.
Mirror movements (MMs) are involuntary movements executed on one side of the body during voluntary movements of the contralateral homologous body parts which may abnormally persist into adulthood. In 6 subjects affected by persistent MM with autosomal dominant inheritance, movement-related cortical potentials (MRCPs) during self-paced, voluntary extensions of either the left or right middle finger were recorded from 30 EEG electrodes simultaneously with the electromyogram (EMG) of both extensor digitorum communis muscles. The negative potentials before and during EMG onset were evaluated statistically for the two electrodes next to the cortical hand areas. A comparison with 7 normal subjects revealed no marked differences for the Bereitschaftspotential (BP) and the negative slope (NS'). Only in the periods around EMG onset (from -50 to +50 msec) a significant difference between both groups was found. The MM subjects showed fairly symmetric potentials over the right and left hemispheres, whereas the potentials of the control subjects were lateralized to the hemisphere contralateral to the intended movement. No difference was found for the amplitude of the maximum negative peak of MRCP following EMG onset. Our data showed no evidence for a different type of movement preparation in MM subjects as compared to normals. We propose that the additional ipsilateral cortical activation around movement onset may be the cortical mechanism, which compensates for abnormal ipsilateral corticospinal pathways in subjects with persistent MM.
Research on fading and delay procedures has shown that extra-stimulus prompts frequently fail to help children learn difficult discriminations. The present study analyzed two delay conditions for an extra-stimulus prompt to help preschoolers discriminate mirror-image stimuli as a function of the configurations and locations of the prompts. All subjects were selected on their ability to discriminate the task stimuli in the presence of a third stimulus, a replica of the S+ and an arrow pointing to that stimulus; and on their inability to do so without these stimuli. Experiments 1 and 2 compared these prompt configurations (S+ replica, arrow) when presented equidistant from the task stimuli. Experiment 3 analyzed the contribution of the replica configuration in terms of its location, in between stimuli or immediately above the S+. Experiment 4 investigated the extent to which the results of the previous experiments could be influenced by the methodology for the assessment of prompt control. The results consistently demonstrated that most subjects did not learn the task unless the extra-stimulus prompt had the same configuration as the S+ and was located equidistant from both task stimuli.
Progressively delayed extra-stimulus prompts were used to help normal preschool children discriminate left-right mirror-image stimuli. Two issues were addressed, the attention guiding properties of the prompts and the necessity for their gradual elimination. The study consisted of four experiments in which one or multiple prompt conditions were used. Each condition involved three prompts: a reference prompt for indicating the S+ and two superimposed prompts, one on the S+, and one on the S-. The prompts required subjects to respond to the orientation of the S+ (Orientation condition) or to the location of the reference prompt (Location condition); or allowed them to respond to the discriminative shapes of the superimposed prompts (Shape condition). The results showed the following. First, most subjects rapidly learned to respond to the Orientation prompts. Second, delayed orientation prompting was always successful regardless of how the prompts were eliminated. Delay training was never successful in either of the other two conditions. Third, the Orientation condition did not reliably produce learning unless the delayed prompting procedure was used.
We have used a resonant mirror biosensor to determine the kinetics of binding of four antibodies, and their Fab' fragments, to their antigen, the plant-derived ribosome-inactivating protein (RIP) saporin. The analysis of the affinity of the antibodies was in reasonable agreement with values obtained by conventional techniques. However, the kinetic data showed that all four antibodies have a high dissociation rate constant (kdiss). These antibodies have been used in the construction of bispecific antibodies used to deliver saporin to tumour cells, and it is highly probable that the in vivo efficacy of the bispecific antibodies is limited by the high rate of dissociation of antibody-toxin complexes.
A portable and collapsible mirror system has been described that enables both lateral profiles and anterior facial views to be recorded with a single photograph in a standardized and reproducible manner. Therefore, routine records and measurements can be made in the many branches of dentistry that plan and execute treatments which could change the facial form of the patient.
Reading performance is poorer in the peripheral than in the central visual field, even after size-scaling to compensate for differences in visual acuity at the different eccentricities. Since several studies have indicated that the peripheral retina is deficient with respect to spatial phase discrimination, we compared the psychometric functions for detection (D) and identification (I) of size-scaled, mirror-symmetric letters (i.e. letters differing in the phase spectra of their odd symmetric components) at three inferior field eccentricities (0, 4, and 7.5 deg) using a two-alternative, temporal, forced-choice procedure and retinal image stabilization to control retinal locus. Each subject's data were fit with Weibull functions and tested for goodness-of-fit under several hypotheses. This analysis revealed that while the psychometric functions were of constant shape across eccentricity for the respective tasks, they showed statistically significant variations in the D/I threshold ratios. However, these variations were so small that poorer reading outside the fovea is unlikely to be due to reduced letter discriminability that might occur secondary to a loss of peripheral field phase sensitivity.
An 18-year-old male medical student presented with subarachnoid hemorrhage. Other than stiffness of the neck, the neurological examination yielded normal findings. Bloody cerebrospinal fluid was obtained by lumbar puncture. Bilateral carotid arteriography revealed a right internal carotid artery aneurysm at the level of the posterior communicating artery. The angiogram of the left carotid artery was entirely normal. A right trapping procedure followed. The patient was asymptomatic for 4 years, when a repeat subarachnoid hemorrhage occurred. A new (mirror) aneurysm on the opposite (left) internal carotid artery was at this time demonstrated by repeat bilateral carotid arteriography. The newly developed aneurysm was successfully clipped. The patient has led a normal, useful life, with no recurrent episodes of subarachnoid hemorrhage in the next 18 years.
We report 12 children with severe obesity in very early childhood who had no evidence of organic causes for their obesity and whose families evidenced psychosocial dysfunction comparable to that often seen in growth failure of psychosocial origin. Features seen include family disorganization, separation of mother and child, displacement of child care to others, maternal depression, denial of the growth abnormality, hostility towards health care providers, and inconsistent medical follow-up. In all cases, parental limit setting was impaired. We suggest that this condition should be called "severe obesity of psychosocial origin." Very severe obesity of early childhood may be conceptualized as the mirror image of growth failure. Like growth failure, it requires evaluation and management focused on psychosocial issues. Research is needed to clarify the prevalence, diagnostic features, and optimal treatment of obesity of psychosocial origin.
A new technique was developed for visualizing virus particles electrophoretically transferred from infected leaves to nitrocellulose membranes. This technique was used to study the distribution of peanut mottle virus (PMV) particles in vivo. The immobilized transferable virus proteins from leaf tissue to nitrocellulose membranes were detected by an enzyme-linked immunobinding technique. The free binding groups on the nitrocellulose membrane were blocked with casein. The nitrocellulose membrane was then treated with PMV-specific antiserum. The virus-bound antibodies were located by protein A-peroxidase or protein A-alkaline phosphatase conjugate followed by the peroxidase substrate mixture, 4-chloro-1-naphthol and H2O2, in the first case or the alkaline phosphatase substrate mixture, 5-bromo-4-chloro-3-indolyl phosphate and Nitroblue tetrazolium in the second case. The locations of virus particles were detected by the corresponding reaction product. A mirror image was obtained on nitrocellulose membrane showing a pattern identical to that of necrotic lesions on leaf pieces but with a significantly larger size of local lesion copy, indicating the presence of virus particles in the apparently healthy tissue outside the necrotic lesion. The new technique is expected, because of its relative simplicity and sensitivity, to be useful for many other fields of biological research where the in vivo distribution of pathogens, antigenic molecules including drugs, or cells of specific antigenic molecules such as cancer or genetically engineered cells needs to be investigated.
A right-sided heart associated with mirror-image atrial arrangement (situs inversus) is a rare condition. The incidence of coronary arterial disease in this setting is probably similar to that in the general population. Description of coronary angiography in this condition is very rare. We have recently catheterized such a patient. The necessary approach to coronary angiography is emphasized.