Clinical findings in a patient mosaic for a supernumerary ring chromosome 20.

Marker chromosomes present a problem in genetic counseling because there are often no clear phenotype-karyotype correlations. We present the clinical findings in a patient who is mosaic for a supernumerary marker chromosome 20 determined by fluorescence in situ hybridization (FISH) and compare these findings to others reported in the literature.

Functional motion of the medial column joints of the foot during propulsion.

Motion in the ankle, subtalar, midtarsal, and first metatarsophalangeal joints has been well documented. However, motion in the first metatarsocuneiform, the first cuneonavicular, and the first interphalangeal joint has not been addressed. Motion in these joints has not been documented because many believe that little motion occurs at these joints, and because of the difficulty in assessing motion at these joints. Using two-dimensional motion analysis, the authors present sagittal plane ranges of motion occurring in the first metatarsophalangeal joint, the first metatarsocuneiform joint, the medial cuneonavicular joint, and the first interphalangeal joint during the propulsive period of gait. This pilot study indicates that sagittal plane motion between the navicular and calcaneus and between the first metatarsal and first cuneiform are very mild and inconsistent. However, plantarflexion motion between the first cuneiform and the navicular is significant and comprises most of the plantarflexion motion of the first ray during propulsion. Motion in the first interphalangeal joint is slight during the first 80% of the propulsive period but shows slight-to-moderate dorsiflexion during the last 20% of the propulsive period of gait.

1998 William J. Stickel Gold Award. The effects of extrinsic muscle forces on the forefoot-to-rearfoot loading relationship in vitro. Tibia and Achilles tendon.

The effects of muscular activity on the distribution of forces under the foot, as well as within the foot, are of great importance for determining the mechanisms of foot pathologies. Limited data exist concerning muscle forces during the gait cycle and the effects of muscle forces conveyed to the ground-reactive forces of the foot. The authors developed a cadaveric loading system to determine the effects of force applied to the Achilles tendon on the forefoot-to-rearfoot loading relationship in eight cadaveric specimens. The study indicated that, during axial loading of the tibia, force was inherently transferred from the rearfoot to the forefoot. However, the observed forefoot-to-rearfoot loading relationship did not match the predicted loading relationship from a rigid-body diagram, as would be observed in a class I lever. The results indicated that, as the force was increased on the Achilles tendon, the change in loads on the forefoot and rearfoot was not linear. Specimens with calcaneal inclination angles greater than 20 degrees demonstrated a more linear increase as compared with those with inclination angles less than 20 degrees.

Dialysis or death? Doctors should stop covering up for an inadequate health service.

Doctors who entered the National Health Service to practice medicine now find themselves forced to practise selection. It seems that patients are being lost at GP level. Surely the basis of a good relationship between doctor and patient relies on trust and trust is based on truth which should not be concealed from patients. And should any one dare decide the quality of life for another human being?

KIE: Ward, president of the British Kidney Patient Association, charges that the underfunded Renal Replacement Programme of the National Health Service (NHS) is denying dialysis to medically qualified patients based on social factors and physician-determined quality of life criteria. She deplores physicians' cover-up of the inadequacies of the NHS by using these criteria, by not offering dialysis as an option, or by declaring it not medically indicated. The author urges physicians to reveal the truth to patients and to unite in proclaiming, "We cannot practise medicine under these conditions."

[Gene therapy and its applications]. / La terapia génica y sus aplicaciones.

Gene therapy consists in the introduction of genes in cells of the human organism. It allows the treatment of not only monogenic diseases (those in which one gene is altered, such as rare enzymatic diseases), but also of diseases in which there is an acquired gene alteration such as AIDS and cancer, and diseases in which several genes and the environment interact, such as diabetes and coronary artery disease. In the few years of development of this therapy several clinical trials have been approved, that, along with experiment of this therapy several clinical trials have been approved, that, along with experimental research, are offering promising results. In this new field of modern medicine, specially in experiments related to genetic manipulation of germinal cells, ethical aspects have great importance.

Truncation of the A alpha chain of MHC class II molecules results in inefficient antigen presentation to antigen-specific T cells.

Antigen presenting cells (APC) expressing MHC class II molecules composed of chains with part or all of the cytoplasmic domains deleted are inefficient at presenting hen egg lysozyme peptides to antigen specific T cell hybrids compared with APC that express wild-type MHC class II molecules. This effect is most apparent for mutants in which the alpha chain has been truncated. The inefficiency in antigen presentation can be amplified by pulsing the APC for 4 h with peptide rather than having peptide present throughout the presentation assay. Fixation of antigen-pulsed APC improves the capacity of APC with truncated class II molecules to stimulate T cell hybrids. Fixation of APC prior to exposure to antigen also leads to significant improvement in antigen presentation by the truncated class II molecules. Because the inefficiency of a given hybrid for antigen presentation does not correlate with its ability to transduce a signal as measured by protein kinase C translocation, we suggest that defects in this pathway are not the only cause of impaired antigen presentation. However, because previous studies have demonstrated the need for an intact cytoskeleton for successful antigen presentation, we propose that the carboxy truncated class II molecules are inefficient in antigen presentation because they are unable to generate the signal that ultimately leads to their interaction with the cytoskeleton. These observations underscore the complexity of the events that are required for achieving effective interactions between MHC class II molecules and TCR, and suggest, with regard to efficient antigen presentation, that the physical state of the class II molecules is at least as important as their signal transducing capacity.