A controlled comparison of light box and head-mounted units in the treatment of seasonal depression.

BACKGROUND: Patterns of response to the light box and head-mounted unit (HMUs) in seasonal affective disorder (SAD) appear to differ. The current study employed a "no light" condition to compare the response rates with the light box and HMU against a plausible placebo. METHOD: Forty-three subjects with DSM-III-R nonpsychotic, unipolar major depression, seasonal subtype, were randomly assigned, in a double-blind manner, to receive 2 weeks of active treatment with a light box (N=9) or HMU (N=12) that emitted no visible light, or 2 weeks of placebo treatment with a light box (N=12) or HMU (N=10) that emitted no visible light. Response was defined as a 50% or greater reduction in both the 17-item "typical" score and 8-item "atypical" score on the Structured Interview Guide for the Hamilton Rating Scale for Depression-SAD version (SIGH-SAD). RESULTS: Using ANOVA for repeated measures, with change in total SIGH-SAD score as the dependent measure, we found no significant main effect of light (F=0.20, p=N.S.) or unit (F=0.50, p=N.S.), and no interaction (F=0.21, p=N.S.). Using log-linear analysis, we found no significant difference in response rate between the four cells (likelihood ratio chi-square = 2.1, p=N.S.). Using chi-square analysis, we found no significant difference in response rates between patients who received light (48%) versus patients who received no light (41%; chi-square = 0.2, p=N.S.) or between patients who received the light box (38%) versus HMU (50%; chi-square = 0.62, p=N.S.). CONCLUSION: The failure to detect any significant difference in efficacy between active and placebo treatments calls into question the specificity of light in light therapy for SAD. Methodological limitations, particularly small sample size, are discussed.

Early mobilization following carpal tunnel release. A prospective randomized study.

A prospective randomized study was undertaken of 50 consecutive patients undergoing surgery for idiopathic carpal tunnel syndrome to determine the value of splintage of the wrist following open carpal tunnel release. Patients were randomized to either be splinted for 2 weeks following surgery or to begin range-of-motion exercises on the first post-operative day. Subjects were evaluated at 2 weeks, 1 month, 3 months, and 6 months after surgery by motor and sensory testing, physical examination, and a questionnaire. Variables assessed included date of return to activities of daily living, dates of return to work at light duty and at full duty, pain level, grip strength, key pinch strength, and occurrence of complications. Patients who were splinted had significant delays in return to activities of daily living, return to work at light and full duty, and in recovery of grip and key pinch strength. Patients with splinted wrists experienced increased pain and scar tenderness in the first month after surgery; otherwise there was no difference between the groups in the incidence of complications. We conclude that splinting the wrist following open release of the flexor retinaculum is largely detrimental, although it may have a role in preventing the rare but significant complications of bowstringing of the tendons or entrapment of the median nerve in scar tissue. We recommend a home physiotherapy programme in which the wrist and fingers are exercised separately to avoid simultaneous finger and wrist flexion, which is the position most prone to cause bowstringing.

A respirometric method for the assessment of ready biodegradability: results of a ring test.

A collaborative exercise involving twelve laboratories was organized for the European Economic Community to check the validity of an enclosed respirometric method for assessing the ready biodegradability of test chemicals, including insoluble substances. The method, based partly on the OECD-Japanese Ministry of International Trade and Industry (MITI) I method (301C) and partly on the U.K. method, allowed the use of a less restrictive, natural inoculum and a wider variety of respirometers than the original MITI I method. Eight compounds of a wide range of degradative behavior were tested over an incubation period of 28 days. The agreement between participating laboratories in the lag period before biodegradation started and in the proportions of theoretical oxygen uptake achieved was at least as good as in other ring tests; it is proposed that the method be accepted. Differences in behavior of pentaerythritol reported here and in the literature are examined and suggestions for future study are discussed.

A mathematical model of biodegradability screening tests as an aid to interpretation of observed results.

A mathematical model, based on a modification of the Michaelis--Menten and Monod equations describing bacterial growth, has been used to predict the course of removal of the organic substrates in the modified OECD and other screening tests. A range of initial concentrations of bacteria in the inoculum has been selected, using published data on the total bacterial count in secondary sewage effluents and activated sludge, to simulate the wide range of volumes of these materials used in practice. The arbitrary definition of ready biodegradability adopted by the OECD, that is, 5 to the equivalent of 70% DOC removal in not more than 10 days in a total incubation period of 28 days, is expressed in terms of inoculum size and kinetic constants. Modifications are proposed to the screening test with the object of making it more useful and realistic in predicting whether or not a chemical will be removed in sewage treatment.