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Biomedical subjects

J S Cox

Publications and source records attributed to J S Cox.

At least 19 recordsLinked to original sources

A promoter element that exerts positive and negative control of the interleukin 2-responsive J-chain gene.

In a primary immune response a signal from interleukin 2 (IL-2) induces B lymphocytes to express the gene for the IgM joining component, the J chain. The signaling mechanism was pursued in this study by examining the J-chain gene 5' flanking region for regulatory sequences and interacting nuclear factors. The analyses identified a major control region located between -75 and -45 that encodes two adjacent elements: a T-rich sequence (JA) containing a single positive regulatory motif and an A+G-rich sequence (JB) containing overlapping positive and negative regulatory motifs. Dissection of the two elements indicated that the bifunctional JB sequence is the likely target of the IL-2 signal. The evidence was based on findings that (i) JB activity correlated with J-chain gene transcription--i.e., JB acts as a repressor in J-chain-silent B cells and as an activator in J-chain-expressing cells, and (ii) JB activator function is mediated by a B-cell-specific nuclear protein, NF-JB, that exhibits an IL-2-responsive binding pattern.

Animals

Long-term outcome of a self-help very-low-calorie-diet weight-loss program.

This paper presents 90-wk data on five seriously overweight subjects originally brought together for 1-2 wk in simple residential accommodation to share the experience of beginning a program of very-low-calorie dieting. All subjects have remained well below their starting weight; four of the five subjects have continued to lose weight (weight losses 33.7-66.8 kg), now weighing less than at the end of the first 26 wk previously reported (1). It is proposed that this self-help group model, incorporating a very-low-calorie diet, is valuable for the long-term management of obesity.

Behavior Therapy

Patellofemoral problems in runners.

Unlike twisting and cutting sports, in which there are torsional forces placed on the knee, distance running involves straight line motion. The biomechanics of running usually insure a relatively smooth tracking of the patella in the femoral groove, so it is rare for a runner to experience an acute traumatic injury of the joint. Since such injuries are rare, this article concentrates on stress-related patellofemoral syndromes that are seen in runners.

Athletic Injuries

Surgical and nonsurgical treatment of acute ankle sprains.

In the treatment of eversion injuries or tears of the medial structures, exact anatomic restoration is mandatory, and this must be accomplished by either closed reduction or surgery. The treatment of lateral ankle ligament injuries is usually cast immobilization, taping, or a cast-brace. Surgical treatment of lateral ankle ligament sprains is performed only on those highly competitive young individuals who require an almost normally functioning ankle.

Ankle Injuries

"Normal" talar tilt angle.

A study to determine the degree of normal talar tilt in individuals with no history of ankle injuries was performed on 404 ankles of 202 midshipmen at the U.S. Naval Academy. Manual inversion stress roentgenograms were used to test this group of young healthy adults, most of whom were males. Of the 404 ankles tested, only 39 (9.7%) had any measurable talar tilt and only 7 ankles (1.7%) had a tilt over 5 degrees. Normal talar tilt does not range to 23 degrees. A normal ankle in a healthy young adult with no history of trauma has a small probability of having any talar tilt. When stress roentgenograms are used to evaluate a fresh lateral ankle ligament sprain in this type of individual, there is a very high probability that talar tilt over 5 degrees would represent significant injury to one or more of the lateral supporting structures.

Adolescent

Interaction of cromolyn sodium in aqueous solution with magnesium ions.

The interaction of the antiasthmatic drug cromolyn sodium with Mg2+ ions in solution was studied. Selective ion electrode and torsion viscometer measurements were used to establish the degree of interaction. At the concentrations studied, the cromolyn ion had no more affinity for Mg2+ than SO42-. However, thixotropic gels were formed between 4 X 10(-2) M cromolyn sodium and 4 X 10(-4) Mg2+. At lower concentrations of Mg2+, viscosity still increased significantly. However, when the cromolyn concentration was lowered, the increase in viscosity was much less marked.

Chemical Phenomena

The degenerative effects of partial and total resection of the medial meniscus in dogs' knees.

An experimental effort to determine the degenerative effects in the articular cartilage of the knee joint caused by meniscectomy was performed by doing partial and total meniscectomies on the medial compartment of dogs' knees. Gross and microscopic pathological changes in teh articular cartilage were studied by sacrificing the dogs at intervals of three to ten months. Results indicated that meniscectomy is not a benign procedure, and the removal of a meniscus in itself can lead to degenerative changes in the knee joint. Partial meniscectomy leads to less severe degenerative changes with the degree of change directly related to the amount of meniscus removed. In total meniscectomies when meniscus regeneration occurred, the cartilage surfaces where the meniscus had regenerated were protected. The degree of degenerative change was directly related to the amount of fibrocartilage that remained absent. Therefore, the knee menisci function to protect the articular cartilages from degenerative damages, but the exact mechanism of this is unknown.

Animals