Characteristics of impaired awareness after traumatic brain injury

The condylar constrained total knee arthroplasty was performed on 29 patients undergoing 33 procedures and were reviewed clinically and radiographically at an average follow-up of 5 years (range, 2-10 years). There were 21 women and 8 men. The average age at the time of surgery was 70 years (range, 32-84). Of the 16 knees that were revision total knee arthroplasties, 8 had a previous infected total knee arthroplasty, and 17 knees had severe deformities requiring the use of the condylar constrained prosthesis. The patients were rated according to the Knee Society clinical and radiological evaluation protocol. Measurements of femoral and tibial component position were obtained as well as femoral tibial angle, patella position, and cement bone radiolucencies. All clinical measurements were made by an independent physical therapist. Clinical results revealed an improvement from an average preoperative knee score of 38 points to an average postoperative score of 86 points. The clinical results for 19 (58%) knees were excellent, 8 (24%) had a good result, 1 (3%) was fair, 2 (6%) were poor, and 3 (9%) were failures. The patients' average functional levels increased from 24 to 58. The final average flexion was 96 degrees. Three knees have been revised (9%). One was revised for recurrent infection, one for periprosthetic fracture, and one for mechanical loosening of the tibial component. There were no other knees with evidence of radiologic loosening. We conclude that the condylar constrained total knee prosthesis provides an acceptable solution for revision and complex primary total knee replacements at an intermediate follow-up term of 5 years.     

Use of propensities of amino acids to the local structural environments to understand effect of substitution mutations on protein stability

Advances in site-directed mutagenesis and other genetic engineeringtechniques have made it possible to create novel proteins of interest. Achallenging aspect of these studies is to understand the effect ofsubstitution mutations on folding and stability of natural proteins. Wepresent an analysis of protein structure data, available from theliterature, for which substitution mutations have been made and changes instability characteristics are reported. Amino acid structural environmentparameters have been computed for a set of 304 non- homologous bestresolved protein structures. The structural environment parameters wereused to calculate each of the 20 amino acid propensities to a givenstructural environment. The observed increase or decrease in stability uponmutation was found to be correlated with the average residue structuralenvironment propensity of wild-type residue versus mutant residue. Theanalysis presented here helps identification of less optimally placedresidues in a given protein structure, and suggests possible substitutionmutations to a residue with higher propensity to the corresponding localstructural environment. We propose that such substitution mutations,suggested based on amino acid propensities to local structuralenvironments, should bestow higher stability to the protein structure.     

Randomised double-masked placebo-controlled trial of a treatment for congenital nystagmus

Several therapies have been developed for congenital nystagmus (CN) but without placebo-controlled trials. We investigated a treatment which combined two therapies that had been advocated by several authors and were reported to improve visual acuity (VA). A placebo treatment was designed to mimic the time, attention, 'high tech' apparatus, and the explanation used in the experimental treatment. To each group, 38 subjects with CN were randomly allocated. Their VA and contrast sensitivity (CS) were assessed three times before undergoing treatment for 6 weeks and then once more. An improvement in VA occurred, however, this was not significantly different in the two groups. The improvement in CS was greater in the experimental than in the control group, but the difference failed to reach significance in most statistical tests. We conclude that putative therapies for CN should be assumed to be placebos until proven otherwise with randomized controlled trials.     

Incidence and evolution of moles and the relationship to malignant melanoma in eastern India

Malignant melanoma is rather uncommon in India. Pigmented moles are also less common than among Caucasians. The fewer number of moles probably is one factor responsible for the relative rarity of malignant melanomas in this area.