Carotenoids up-regulate connexin43 gene expression independent of their provitamin A or antioxidant properties.

Epidemiological evidence and studies in whole animals and cell culture have indicated that carotenoids have cancer chemopreventive action. In mouse C3H10T1/2 cells, this activity is highly correlated with the ability of carotenoids to up-regulate gap junctional intercellular communication. Here, we report that in mouse cells, carotenoids increase the expression of connexin43, a gene that encodes a major gap junction protein. This effect appears unrelated to their provitamin A or antioxidant properties, since carotenoids with and without provitamin A activity increased levels of connexin43 mRNA and protein, whereas the antioxidants methyl-bixin and alpha-tocopherol were inactive. Moreover, the active carotenoid canthaxanthin did not induce the vitamin A-inducible gene retinoic acid receptor-beta. Connexin43 is the first carotenoid-inducible gene described in mammals. By indicating an additional pathway through which carotenoids function, these data provide a mechanistic basis for cancer chemoprevention by carotenoids and may lead to a re-evaluation of carotenoid physiology.     

Imaging Barrett's oesophagus

Eight patients who had Barrett's oesophagus confirmed by histology are presented. All had barium swallow examinations and technetium-99m sodium pertechnetate (99Tcm-pertechnetate) scintigraphy, the findings of which are reviewed and discussed. The most valuable diagnostic signs on barium swallow examination related to the site of the stricture and the presence of mucosal outpouchings. Scintigraphy was positive in all eight cases. Patients suspected of having Barrett's oesophagus on barium swallow examination should undergo scintigraphy. When the latter is positive, the endoscopist should be alerted to obtain biopsies not only at the site of stricture but serially as far as the gastrooesophageal junction.     

Biomechanics of the golf swing in players with pathologic conditions of the forearm, wrist, and hand

Golf is an activity generally stressful to the hands and wrists and particularly can produce increasing symptoms in players with underlying problems such as hand and wrist arthritis or tendinitis. The purpose of this study was to quantitate wrist motion and club head/ball impact force in subjects with pathologic conditions of the hand, wrist, or forearm, within a laboratory environment. A regular straight-handled golf club was compared to a new BioCurve handle design that has a 19 degrees ulnar bend. We measured and compared the effect of the two grips on wrist motion, club head velocity, ball impact force, ball impact location, and isometric torsional strength in 20 subjects who had a variety of upper extremity disorders. This data was then compared to data collected in an identical fashion from golfers without such conditions. The results of our study show that there were no differences related to club handle design on impact force or impact location, club head velocity, or club head path and face angle. Wrist kinematic differences were minimal between handle designs. The differences that were significant (P less than 0.05) centered around the decreased ulnar deviation of the left hand that resulted when subjects used the BioCurve handle design, which also allowed greater resistance to torque than the straight grip club. In addition to collecting objective data, we asked subjects for their opinions of the two grips. As a whole, the normal group and the group with pathologic conditions noted more comfort, improved grip, and less shock transmission with the BioCurve handle.     

Free flap reconstruction of the lower extremity in the elderly

Summary Over a four year period, thirteen patients over the age of 60 (mean 69 years) underwent reconstruction of lower extremity defects with free tissue transfers. Ten latissimus dorsi, one tensor facia lata, and two rectus abdominus free flaps were used. Despite significant risk factors which included previous tobacco use, hypertension, diabetes mellitus, and angiographic vessel abnormalities, ten of thirteen cases had successful outcomes. There was one acute flap failure secondary to arterial thrombosis. Four flaps had delayed healing, with one patient eventually requiring amputation secondary to persistent pain and wound drainage. This experience demonstrates that free flap reconstruction of lower extremity defects in the elderly patient is a reasonable alternative to amputation when other options are limited.From the Section of Plastic and Reconstructive Surgery at the Mayo Clinic and Mayo Foundation, Rochester, Minnesota, USA Requests for reprints: J. Fisher, M.D.     

Contraceptive use and sterilization among Puerto Rican women.

A comparison of contraceptive use in the early to mid-1980s among married Puerto Rican women aged 15-49 in the New York City area reveals that island-born Puerto Rican women living in New York rely on female sterilization to nearly the same extent as do women living in Puerto Rico (45% and 41%, respectively) and that mainland-born Puerto Rican women use sterilization as much as do all women in the United States (19% for both groups). Puerto Rican women in New York use reversible methods to a greater extent than do women in Puerto Rico (22% v. 16%), but to a lesser extent than do all women in the United States (37%). Although mainland-born Puerto Rican women in New York use reversible methods more than do island-born women in New York (42% v. 23%), they tend not to adopt these methods to the same extent as do all U.S. women during the early reproductive years, when education and employment are critical to socioeconomic attainment.     

Cell renewal and gene expression in the trachea of hamster at different ages.

The tracheal mucosa of the Syrian golden hamster has been extensively employed as a model system for respiratory tract cell renewal, injury, and carcinogenesis. However, baseline cell kinetic data are not available for normal juvenile and adolescent animals in which the mucosa and cartilage are rapidly enlarging. The objective of this research was to elucidate alterations in cell kinetics, epithelial morphology, and gene expression in the trachea of hamsters at different ages. Cell kinetics were examined by 3H-thymidine labeling indices, morphology by light and electron microscopic examination, and gene expression by slot blot analysis. Results showed that mucosal epithelium of the young and adolescent hamster undergoes cyclic necrosis and cell shedding, exposing portions of the elastic basal lamina. Epithelial shedding was associated with hyperplasia and squamous metaplasia. Additionally, the labeling indices of mucosal epithelial cells and chondroblasts also exhibited variable patterns which were associated with a cyclic pattern of expression of c-fos and c-erbB2 proto-oncogenes and epidermal growth factor receptor.