Efficacy of Full µ-Opioid Receptor Agonists is not Impaired by Concomitant Buprenorphine or Mixed Opioid Agonists/Antagonists - Preclinical and Clinical Evidence.

Buprenorphine and the mixed agonists/antagonists nalbuphine and pentazocine, formerly classified as µ-opioid (MOP) receptor antagonists, have more recently been shown to be partial to full agonists of the human MOP receptor. These receptors do not necessarily have to be maximally activated for a full physiological response. Partial agonists can also sufficiently stimulate signaling processes leading to a full analgesic response, as shown by the effectiveness of buprenorphine, nalbuphine and pentazocine in animal pain models and in clinical settings where these drugs induce analgesia with full efficacy without a ceiling effect. Submaximal doses of MOP receptor analgesics combined with submaximal doses of buprenorphine, pentazocine, or nalbuphine result in additive to over-additive antinociceptive effects in animal experiments. Only when doses are given that exceed the therapeutic dose range may the antinociceptive effect be reduced to the effect of either opioid alone. The analgesic effects of pentazocine and nalbuphine combined with morphine are reported to be additive or over-additive in various clinical pain conditions. Buprenorphine, which clinically behaves as a full MOP receptor agonist for pain relief, can be combined with full opioid agonists without precipitating withdrawal. Thus, the overall evidence on the analgesic effects of buprenorphine, pentazocine or nalbuphine combined with opioid analgesics under various clinical pain conditions contradicts the consensus that these compounds diminish MOP receptor analgesia when co-administered with a full MOP receptor agonist.

Ranitidine does not affect psoriasis: a multicenter, double-blind, placebo-controlled study.

BACKGROUND: Data from open studies suggest that ranitidine has a beneficial effect on psoriasis and is well tolerated. OBJECTIVE: Our purpose was to determine the effectiveness of ranitidine in a 24-week, multicenter, double-blind, placebo-controlled, dose-comparing study of 201 patients with psoriasis. METHODS: Patients with moderate to severe psoriasis who had stopped systemic antipsoriatic therapy, including PUVA and UVB, for at least 10 weeks were included. After a washout period of 2 weeks, patients were randomly allocated to use either ranitidine, 150 mg twice a day; ranitidine, 300 mg twice a day; or placebo for up to 24 weeks. Assessment with the Psoriasis Area and Severity Index was performed at weeks 3, 6, 9, 12, 18, and 24 after randomization. Reduction of the Psoriasis Area and Severity Index score by 70% at the completion of the study was considered a treatment success. RESULTS: The success rates at week 24 in the 300 mg, 600 mg, and placebo groups were 11%, 5%, and 12%, respectively. No significant differences were observed between the three treatment groups at any stage of the study. CONCLUSION: This study provides strong evidence that ranitidine does not affect the skin disease in patients with psoriasis.

Does color vision deficiency in the endoscopist influence the accuracy of endoscopic diagnosis? An anonymous study with Dutch gastrointestinal endoscopists.

Colors play a major role in the endoscopic diagnosis of many gastrointestinal conditions. Gastrointestinal endoscopists in the Netherlands are predominantly male (> 90%), and from population data it is to be expected that approximately 8% will have a color vision deficiency. The present study was designed to assess the prevalence of color vision deficiencies amongst Dutch gastrointestinal endoscopists and to determine whether color vision deficiency affects an endoscopist's diagnostic skill. One hundred and thirty-nine gastroenterologists and physicians of internal medicine took an F2 color vision test and assessed nine videofragments of endoscopies. Color vision deficiencies were detected in 8% of Dutch gastrointestinal endoscopists. In one out of the nine video excerpts of endoscopies, a statistically significant difference was detected between test subjects with and without a color vision deficiency. However, this video excerpt showed a green pea, which could not be mistaken for a polyp at polypectomy. The study therefore does not show any effect of color vision deficiencies on endoscopic skills, nor does it show any deviant prevalence of color vision deficiencies amongst Dutch gastrointestinal endoscopists.

A study on the dimeric structure of creatine kinase (EC 2.7.3.2).

The generally accepted dimeric structure of creatine kinase (CK) is one in which M subunits and B subunits can occur. This paper reports the existence of three MM-bands and two MB-bands in human sera with increased CK-activity. These findings and supplementary data gathered from hybridisation experiments have led to the conclusion that there are two different M subunits, which can both occur in the enzyme in vivo. Further, findings are reported on the different CK-isozyme patterns of extracts from the cerebellum and from the cortex and the medulla of the cerebrum.