Effect of glucosamine hydrochloride in the treatment of pain of osteoarthritis of the knee

OBJECTIVE

Glucosamine products have been used extensively for the management of pain in osteoarthritis (OA). We investigated the efficacy of the hydrochloride salt of glucosamine on pain and disability in knee OA.

METHODS

At Week -2, subjects were examined, randomized, and instructed to take only prescribed acetaminophen for pain. At Week 0 patients were examined, prescribed acetaminophen, and either placebo or glucosamine hydrochloride (glucosamine). At Week 4 the prescriptions for acetaminophen and placebo or glucosamine were renewed. At Weeks 4 and 8, patients returned diaries and unused medications, and were examined. The WOMAC questionnaire was administered at Weeks -2, 0, and 8. After completing the randomized 8 week trial, subjects were offered known glucosamine hydrochloride capsules in an 8 week open label trial, with followup telephone survey after the 8 week open label trial.

RESULTS

The primary endpoint (statistically significant difference in WOMAC pain score between Week 0 and Week 8) was not met. However, positive trends were noted for the glucosamine group in 23 of 24 WOMAC questions. A significant difference was noted from Week 5 through Week 8 in the knee examination (p = 0.026) and in the response to a daily diary pain question (p = 0.018). However, responding to the question, "Are you better than at the start of the trial?", 40% of placebo and only 49% of glucosamine subjects answered in the affirmative (p = 0.58). At the end of the randomized trial, 34% of placebo and 47% of glucosamine subjects believed that they had been given glucosamine. After the end of the 8 week open label trial, 77% of the subjects were still taking glucosamine, although now obliged to pay for commercially available products.

CONCLUSION

There was no significant difference in pain reduction between the glucosamine hydrochloride and placebo groups as measured by WOMAC. However, the secondary endpoints of cumulative pain reduction as measured by daily diary and knee examination were favorable, suggesting that glucosamine hydrochloride benefits some patients with knee OA.

Impact of heavy metals on mass and energy flux within the decomposition process in deciduous forests

: Laboratory experiments on microbial decomposition and on the contribution of diplopods to organic matter decomposition in soil were combined with field studies to reveal the major points of heavy metal effects on the leaf litter decomposition process. The study focused on the accumulation of organic litter material in heavy metal-contaminated soils. Microbial decomposition of freshly fallen leaves remained quantitatively unaffected by artificial lead contamination (1000 mg kg(-1)). The same was true for further decomposed leaf litter material, provided that the breakdown of this material was not influenced by faunal components. Although nutrient absorption in diplopods is affected by high lead contents in the food, this effect alone, however, was shown not to be sufficient for the massive deceleration of the decomposition process under heavy metal influence which could not only be observed in the field but occurred in microcosm studies as well. Reduced reproduction and lower activity of the diplopods most likely were responsible for the observation that lead-influenced diplopods enhanced microbial activity in soil only in a lesser degree than uncontaminated animals did. This effect is assigned to represent the main reason for decreased decomposition rates and the subsequent accumulation of organic material in heavy metal-contaminated soils.

In vitro translation of D2 dopamine receptors and their chimaeras: analysis by subtype-specific antibodies

We have developed a range of specific anti-peptide antibodies directed against the D2 and D3 dopamine receptors, and their alternatively spliced isoforms. To demonstrate the subtype- and isoform-specificities of these antibodies we have expressed the receptors in an in vitro translation system and have immunoprecipitated the expressed proteins. We have shown that the D2 and D3 receptors unexpectedly exhibit different migration properties on SDS-PAGE, in addition to displaying a significant difference between their predicted and apparent molecular weights. We have used D2/D3 chimaeric receptors to show that the differential migration between the subtypes can be attributed to the N-terminal half of the receptor and propose that the highly hydrophobic nature of the receptor proteins underlies their anomalous migration properties.