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Mirror movement: application of movement-related cortical potentials.

In a patient with Kallmann's syndrome (hypogonadotropic hypogonadism and anosmia) manifesting mirror movement, cortical potentials associated with unilateral and bilateral simultaneous voluntary middle finger extensions were studied. Premovement negative slope, which has been shown to reflect preparatory excitation of motor cortex corresponding to the voluntary movement, was recorded bilaterally in this patient in spite of intended unilateral hand movement. It is suggested that mirror movement in this particular patient is generated by unintended excitation of the opposite motor cortex.

Adult↗

Percutaneous balloon valvuloplasty in mirror-image dextrocardia and rheumatic mitral stenosis.

A 28-year-old woman with mirror-image dextrocardia and severe rheumatic mitral stenosis underwent successful percutaneous balloon mitral valvuloplasty (PBMV). Standard technique was altered to include transseptal catheterization via the left femoral vein and inter-atrial septal puncture with the transseptal needle rotated to a 7 o'clock position. The predilatation transmitral gradient (mean) of 16 mmHg decreased to 5 mmHg following PBMV. The valve area improved from 1.0 cm2 to 2.6 cm2. There were no complications. This case illustrates that transseptal catheterization can be accomplished safely in patients with unusual cardiac anatomy and mitral valvuloplasty can be performed in patients with mirror-image dextrocardia and rheumatic mitral stenosis.

Adult↗

Mirror-image response during the first two years of life.

Children aged 1-24 months viewed themselves in planar or distorted mirrors that were either clear or partially occluded. Analysis of videotaped records revealed that interest in viewing one's face did not vary with age among the 1- to 24-month-old subjects. All performed the simple behaviors of observing themselves although the older ones performed more complex (related) behaviors. Neither the flat nor the distorted mirror exposure was preferred suggesting that the infant observes the general configuration of the face for its intrinsic interest. Specific developmental trends were noted in the kind and amount of activity during the 1st 2 years of life culminating in a sequence of behaviors that suggested self-recognition.

Age Factors↗

Absence of self-recognition in a monkey (Macaca fascicularis) following prolonged exposure to a mirror.

To date only chimpanzees, orangutans, and humans have been found capable of recognizing themselves in mirrors. In an attempt to provide a more definitive test of the capacity for self-recognition in monkeys. I gave a preadolescent crab-eating macaque 2400 hr of mirror exposure. However, patterns of self-directed behavior never developed and a more explicit test of self-recognition yielded negative results. The data indicate possible differences between great apes and monkeys in self-awareness.

Animals↗

Mirror densitometry for higher sensitivity and resolution.

In order to increase the pathway of the light inside a gel (or autoradiogram) during scanning, it is placed on top of a mirror and the densitometry is performed in a vertical reflection mode. As the light passes the gel a second time after being reflected by the mirror, the absorbance is nearly doubled. This increase in absorbance results in higher sensitivity and resolution.

Autoradiography↗

Mirror-image duplication of the primary axis and heart in Xenopus embryos by the overexpression of Msx-1 gene.

The Msx-1 gene (formerly known as Hox-7) is a member of a discrete subclass of homeobox-containing genes. Examination of the expression pattern of Msx-1 in murine and avian embryos suggests that this gene may be involved in the regionalization of the medio-lateral axis during earlier development. We have examined the possible functions of Xenopus Msx-1 during early Xenopus embryonic development by overexpression of the Msx-1 gene. Overexpression of Msx-1 causes a left-right mirror-image duplication of primary axial structures, including notochord, neural tube, somites, suckers, and foregut. The embryonic developing heart is also mirror-image duplicated, including looping directions and polarity. These results indicate that Msx-1 may be involved in the mesoderm formation as well as left-right patterning in the early Xenopus embryonic development.

Animals↗

Topological mirror images in protein structure computation: an underestimated problem.

When calculating three-dimensional structures from NMR data, alternative solutions with very large RMS deviation can be obtained. Sometimes local or global inversions of the protein folding can be observed. We call these different solutions topological mirror images, as they keep the correct amino acid chirality. They are observed when the number of restraints is insufficient and represent different solutions from the same scalar information. Therefore they are common in small peptides where the NMR data are often limited and the secondary structure is not very well defined. They can also be observed in large molecules in regions of higher flexibility. In our experience the observation of topological mirror images is independent of the efficiency of sampling of the algorithm used. We present four examples of proteins with different size and folding. We also discuss ways to distinguish among the different solutions.

Acid Anhydride Hydrolases↗

Characterization of ricin heterogeneity by electrospray mass spectrometry, capillary electrophoresis, and resonant mirror.

Electrospray mass spectrometry (ES/MS), capillary-zone electrophoresis (CZE), capillary isoelectric focusing (CIEF), and multianalyte resonant mirror are used to evaluate the heterogeneity of samples of ricin toxins extracted from five horticultural varieties of Ricinus communis seeds: R. communis zanzibariensis, carmencita, impala, sanguineus, and gibsonii. The investigation is also extended to the geographical provenance of the beans. Combining mass spectrometry, CE techniques, and resonant mirror results in a powerful analytical tool capable to characterize and differentiate between different varieties of ricin toxins. Each technique complements the others, adding another level of information. This study reveals a large extent of heterogeneity for each cultivar, demonstrating that ricin toxins consist of a series of glycosylated proteins most likely originating from a multigene family. By combining these techniques, it is possible to differentiate between zanzibariensis and the other four varieties, and that variations in the functional characteristics may be observed between the different cultivars. This study demonstrates that knowledge of the variety of R. communis beans used and their geographical provenance is essential before any type of investigation of ricin toxins is carried out. Consequently, any unusual behavior observed can only be attributed to that particular cultivar studied and not automatically extended to include all R. communis varieties.

Biosensing Techniques↗

A 1.2-megabase BAC/PAC contig spanning the 14q13 breakpoint of t(2; 14) in a mirror-image polydactyly patient.

We previously assigned a 14q13 breakpoint of t(2; 14) in a patient with mirror-image polydactyly to a segment between two loci, AFM200ZH4 and D14S306, within a genetic distance of 0.6 cM. In the present study, we constructed a 1.2-Mb high-resolution physical map with a contig composed of 16 bacterial artificial chromosomes (BACs) and 6 P1-derived artificial chromosomes (PACs) at a region around the breakpoint, extending from D14S75 to D14S728 loci. Thirty-four novel sequence-tagged sites (STSs) were also characterized at this region. Of nine ESTs that had been mapped between D14S75 and D14S288, T99065 was confirmed to be in two BAC clones, B102 and B319. This BAC/PAC contig with STSs is useful for further genomic sequencing, for construction of a transcription map, and for the isolation of the putative gene for mirror-image polydactyly.

Chromosome Mapping↗

Acute lymphoblastic leukemia hand-mirror cells. Study of nine cases.

Acute lymphoblastic leukemia with hand-mirror cells (HMC) was diagnosed in nine adult patients. Blast HMC were seen only in the bone marrow (12-57% range). Cytochemical studies revealed a positive reaction to tartrate-sensitive acid phosphatase in the tail portion of the cells in seven cases, with a strong, localized cytoplasmic reaction in four. Leukemic cells lacked surface immunoglobulins and were E rosette negative in all cases. Normal levels of adenosine deaminase activity (ADA) were found in five of the seven patients. Electron microscope studies confirmed the hand-mirror shape of the cell. These HMC contained large numbers of mitochondria and microspikes in the handle portion of the cell. The patients failed to respond to initial conventional ALL chemotherapy, but the prolonged survival with passable health of the majority of these, despite their lack of complete remission, is emphasized.

Acid Phosphatase↗

Differences between pattern-evoked electroretinograms obtained by a scanning laser ophthalmoscope and by a mechanical mirror system.

Pattern electroretinograms were studied in response to stripe patterns of different spatial frequencies and intensities in the pattern-onset and reversal mode by means of a scanning laser ophthalmoscope and a mechanical mirror system (maxwellian view). The stimulus conditions in both procedures were as close as possible: 31 degrees square field, 633-nm wavelength and the same equipment for recording. The remaining differences between the two methods were the line and pixel structure in the scanning laser ophthalmoscope and the buildup speed (40 ms in the scanning laser ophthalmoscope and less than 1 ms in the mirror system). This difference was reflected in the response peak times of the pattern electroretinogram, which were up to 10 ms in the scanning laser ophthalmoscope measurement. The pattern-related onset response was smaller with the scanning laser ophthalmoscope, indicating a strong sensitivity to the slow build-up speed, while the offset and reversal responses showed no differences in amplitudes. All differences were found only with the use of high luminances. The results suggest that responses evoked with patterns displayed on a television screen could be faster and larger if stimulators faster than the conventional television standard were used. Because of the smallness of onset amplitudes, the pattern-reversal mode might be better for stimulation in a clinical study when the scanning laser ophthalmoscope is used.

Adult↗

MR of right aortic arch with mirror-image branching and a left ligamentum arteriosum: an unusual cause of a vascular ring.

An unusual case is presented of a vascular ring due to a right arch with mirror-image branching and a left ligamentum arteriosum from the descending aorta to the left pulmonary artery. There have been only four previous reports of this rare arch anomaly. In addition, the patient had no underlying congenital heart lesions, which is also very unusual in patients with right aortic arch with mirror-image branching.

Aorta, Thoracic↗

Severe congenital limb deficiencies, vertebral hypersegmentation, absent thymus and mirror polydactyly: a defect expression of a developmental control gene?

We describe two unrelated patients with a complex malformation pattern that may be a candidate for a developmental gene disorder. These two patients had severe, symmetrical upper and lower limb deficiencies, vertebral hypersegmentation, and duodenal atresia. Patient 1 also had mirror-image polydactyly of his feet; patient 2 was athymic. The concurrence in two unrelated patients of additional vertebrae with severe anomalies in limb development, including a symmetrical deficiency of the four limbs and either mirror-image duplication of some toes (only in patient 1) or absence of the thymus (only in patient 2), represents an early alteration in body-plan organization. Since limb development, thymus development and segmentation are possibly under the control of homeobox genes in the human embryo, it seems reasonable that the malformations observed in these two patients resulted from a defect of a gene controlling developmental pattern formation, possibly a homeobox gene or a paired-box gene. Severe limb deficiencies have been reported in other well-known genetic entities, such as Roberts syndrome, Baller-Gerold syndrome, X-linked amelia, and DK-phocomelia syndrome. However, since the specific pattern of anomalies observed in these patients makes the diagnosis of some of the abovementioned disorders unlikely, we conclude that our patients have a previously undescribed disorder.

Abnormalities, Multiple↗

Mirror-image right aortic arch: a proposed mechanism in symptomatic vascular ring.

We describe a rare case of right aortic arch with mirror-image branching and a left ductus arteriosus that form an anomalous vascular ring. The unusual feature of this symptomatic vascular ring is presence of a left (posterior) circumflex descending aorta in lieu of an aortic diverticulum which usually represents the posterior element of the vascular ring associated with right aortic arch and mirror-image branching. This we believe is the seventh reported case of Type 1 right aortic arch and only the third such case with a left circumflex descending aorta. Accurate diagnosis was made by barium esophagogram and angiocardiogram and was confirmed surgically. We propose a new theory as to why some vascular rings formed by the right aortic arch are symptomatic while others are not.

Aorta, Thoracic↗

Acoustic mirror effect increases prey detection distance in trawling bats.

Many different and phylogenetically distant species of bats forage for insects above water bodies and take insects from and close to the surface; the so-called 'trawling behaviour'. Detection of surface-based prey by echolocation is facilitated by acoustically smooth backgrounds such as water surfaces that reflect sound impinging at an acute angle away from the bat and thereby render a prey object acoustically conspicuous. Previous measurements had shown that the echo amplitude of a target on a smooth surface is higher than that of the same target in mid-air, due to an acoustic mirror effect. In behavioural experiments with three pond bats (Myotis dasycneme), we tested the hypothesis that the maximum distances at which bats can detect prey are larger for prey on smooth surfaces than for the same prey in an airborne situation. We determined the moment of prey detection from a change in echolocation behaviour and measured the detection distance in 3D space from IR-video recordings using stereo-photogrammetry. The bats showed the predicted increase in detection distance for prey on smooth surfaces. The acoustic mirror effect therefore increases search efficiency and contributes to the acoustic advantages encountered by echolocating bats when foraging at low heights above smooth water surfaces. These acoustic advantages may have favoured the repeated evolution of trawling behaviour.

Animals↗

French mirror site of the NPAC visible human viewer: first year evaluation.

The NPAC visible human viewer (NPAC VHV), graphical interface written in JAVA, freely accessible by the Web, allows the display of anatomic cross-sections of the Visible Human Project developed by the National Library of Medicine. In April 1997, the Medical Media Library of Lyons undertook the construction of a French-language mirror site of the NPAC VHV. The aim of this work is to evaluate first year utilisation of this site. From May 1st, 1997 to April 30th, 1998, the mirror site was consulted 34,752 times. In 45.14% of cases, the request came from France, in 4.42% of cases from Belgium, in 3.98% from Canada and in 2.12% from Switzerland. Other connections came either from a country responsible for fewer than 1% of connections or from unidentified computers. Data analysis showed a peak of connections between 15:00 and 17:00, and an increased number of connections from September to March 1998. The NPAC VHV is housed in 5 sites in the world. It is a software very simple to use. As the figures have no legends, it is more appropriate for group teaching than for self-teaching.

Anatomy, Cross-Sectional↗

Chiral compounds in metabolism: a look in the molecular mirror.

UNLABELLED: We know that many familiar objects such as gloves, shoes and screws are non identical with their mirror images. The same applies to certain chemical compounds. These compounds show a degree of asymmetry in their structure which means that when looked at in a mirror, their images are not superimposable--they are chiral compounds and have two forms (enantiomers). Until recently biochemists have only been concerned with perhaps one form, other forms having been ignored primarily due to analytical difficulties. We now know of inborn errors of metabolism where one form of a pathological metabolite predominates, thus requiring precise enantiomeric analysis. This article provides a background to the field of enantiomers and their analysis as demonstrated by examples of inborn errors of metabolism and hints at the possible discovery of as yet unidentified metabolic pathways. CONCLUSION: Recent advances in the field of enantiomeric metabolite analysis, in particular the use of enantioselective gas chromatography-mass spectrometry, have an increasingly important role to play, not only in the diagnosis of inborn errors of metabolism, but also to increase our understanding of normal physiological processes.

Adult↗

A non-randomized clinical control trial of Harrison mirror image methods for correcting trunk list (lateral translations of the thoracic cage) in patients with chronic low back pain.

Spinal trunk list is a common occurrence in clinical practice, but few conservative methods of spinal rehabilitation have been reported. This study is a non-randomized clinical control trial of 63 consecutive retrospective subjects undergoing spinal rehabilitation and 23 prospective volunteer controls. All subjects presented with lateral thoracic-cage-translation posture (trunk list) and chronic low back pain. Initial and follow-up numerical pain rating scales (NRS) and AP lumbar radiographs were obtained after a mean of 11.5 weeks of care (average of 36 visits) for the treatment group and after a mean of 37.5 weeks for the control group. The radiographs were digitized and analyzed for a horizontal displacement of T12 from the second sacral tubercle, verticality of the lumbar spine at the sacral base, and any dextro/levo angle at mid-lumbar spine. Treatment subjects received the Harrison mirror image postural correction methods, which included an opposite trunk-list exercise and a new method of opposite trunk-list traction. Control subjects did not receive spinal rehabilitation therapy, but rather self-managed their back pain. For the treatment group, there were statistically significant improvements (approximately 50%) in all radiographic measurements and a decrease in pain intensity (NRS: 3.0 to 0.8). For the control group, no significant radiographic and NRS differences were found, except in trunk-list displacement of T12 to S1, worsened by 2.4 mm. Mirror image (opposite posture) postural corrective exercises and a new method of trunk-list traction resulted in 50% reduction in trunk list and were associated with nearly resolved pain intensity in this patient population. The findings warrant further study in the conservative treatment of chronic low back pain and spinal disorders.

Adult↗