Previous reports have shown that cellular functions could be influenced by visual light (400-700 nm). Recent evidence indicates that cellular proliferation could be triggered by the interaction of a helium-neon laser (He-Ne laser, 632.8 nm) with the mitochondrial photoacceptor-cytochrome c oxidase. Our previous studies demonstrated that He-Ne irradiation induced an increase in cell proliferation, but not migration, in the melanoma cell line A2058 cell. The aim of this study was to investigate the underlying mechanisms involved in photostimulatory effects induced by an He-Ne laser. Using the A2058 cell as a model for cell proliferation, the photobiologic effects induced by an He-Ne laser were studied. He-Ne irradiation immediately induced an increase in mitochondrial membrane potential (delta psi(mt)), ATP, and cAMP via enhanced cytochrome c oxidase activity and promoted phosphorylation of Jun N-terminal kinase (JNK)/activator protein-1 (AP-1) expressions. He-Ne irradiation-induced A2058 cell proliferation was significantly abrogated by the addition of delta psi(mt) and JNK inhibitors. Moreover, treatment with an He-Ne laser resulted in delayed effects on IL-8 and transforming growth factor-beta1 release from A2058 cells. These results suggest that He-Ne irradiation elicits photostimulatory effects in mitochondria processes, which involve JNK/AP-1 activation and enhanced growth factor release, and ultimately lead to A2058 cell proliferation.

Pm'po~: In a randomized, double-blind clinical trial, we compared the postoperative analgesic effect and dose consumption of fentanyl after intraoperative high dose and low dose fentanyl administration. Methods: Sixty ASA class I to II female patients undergoing total abdominal hysterectomy CI-AH), were randomly allocated to receive either I Hg.kg -I (low dose group, n = 30) or 15 Hg.kg -a (high dose group, n = 30) fentanyl during induction of anesthesia. Anesthesia depth was maintained with inhalation of halothane in the low dose group, or combined with 100 Hg'hr -~ fentanyl iv in the high dose group. Postoperative pain was treated with an intravenous patient-controlled analgesia system and was assessed with a visual analog pain score at rest. R~ts: Patients in the high dose group had higher pain intensity at four and eight hours postoperatively, more fentanyl consumption and a greater incidence of emesis in the postoperative period of 16 hr than those in the low dose group (P < 0.05). Heart rate, blood pressure, and respiratory rate were similar between the two groups. C, oncJttdon: Our results suggest that acute fentanyl tolerance develops after administration of high dose fentanyl during surgery and, consequently, results in a higher postoperative pain intensity and greater fentanyl consumption. REsultats : Les patientes qui ont re~u la forte dose ont connu des douleurs plus intenses quatre et huit heures apr~s I'op&ation, ont pris davantage de fentanyl et ont eu une plus grande incidence de vomissements dans les 16 h qui ont suivi I'opEration, que celles qui ont re~u une faible dose (P < 0,05). La fr~quence cardiaque, la tension art&ielle et le rythme respiratoire n'ont pas pr&entd de diff&ence intergroupe. Conclusion : Les r&ultats sugg&ent qu'une tol&ance soudaine au fentanyl se ddveloppe aprEs l'administration peropEratoire d'une forte dose et qu'elle entra~ne, par consdquent, des douleurs postop&atoires plus intenses et une plus grande consommation de fentanyl.

The purposes of this study were to examine the attitudes of physicians regarding the optimal use of analgesics for cancer pain management (CPM), to evaluate their knowledge and attitudes toward opioid prescribing, and to comprehend their perceptions of the barriers to optimal CPM. A survey was conducted on 356 physicians with cancer patient care responsibilities practicing in two medical centers in Taiwan. A total of 204 (57%) physicians responded, including internists (28%), surgeons (27%), oncologists (11%), anesthesiologists (10%), and other specialties (24%). The majority of physicians displayed significantly inadequate knowledge and negative attitudes toward the optimal use of analgesics and opioid prescribing. Multivariate analyses showed that the following six categories of physicians would be inclined to have inadequate knowledge of opioid prescribing: 1) those with perception of good medical school training in CPM, 2) those with perception of poor residency or fellowship training in CPM, 3) those with a medical specialty in surgery, medicine, or oncology (vs. anesthesiology), 4) those with limited clinical experience in cancer patient care (number of patients less than 30), 5) those with a limited aim of pain relief, and 6) those with an underestimation of analgesic effect. Additionally, physicians with inadequate knowledge of opioid prescribing and with hesitation to intervene earlier with maximal dose of analgesia would be inclined to have reluctant attitudes toward opioid prescribing. The most important barriers to optimal CPM identified by physicians themselves were physician-related problems, such as inadequate guidance from a pain specialist, inadequate knowledge of CPM, and inadequate pain assessment. The results of this study suggest that active analgesic education programs are urgently needed in Taiwan.

No abstract

We sought to determine the minimum effective dose of dexamethasone in preventing postoperative nausea and vomiting in women undergoing thyroidectomy. Two hundred twenty-five women (n = 45 in each of five groups) undergoing thyroidectomy under general anesthesia were enrolled in this randomized, double-blinded, placebo-controlled study. Immediately after the induction of anesthesia, patients received IV dexamethasone at doses of 10 mg (D10), 5 mg (D5), 2.5 mg (D2.5), 1.25 mg (D1.25), or saline (S). We found that Groups D10 and D5 were significantly different from Group S in the total incidences of nausea and vomiting, more than four vomiting episodes, the proportions of patients requiring rescue antiemetics, and the incidences of complete responses. The differences between Groups D10 and D5 were not significant. Dexamethasone 2.5 mg reduced the total incidence of nausea and vomiting. Dexamethasone 1.25 mg was not effective. Dexamethasone 5 mg IV is the minimum effective dose in preventing postoperative nausea and vomiting in women undergoing thyroidectomy.

The present study was performed to evaluate the effects of the tricyclic antidepressant amitriptyline on morphine tolerance in rats. Male Wistar rats were implanted with two intrathecal (i.t.) catheters with or without a microdialysis probe, then received a continuous i.t. infusion of saline (control) or morphine (15 microg/h) and/or amitriptyline (15 microg/h) for 5 days. The results showed that amitriptyline alone did not produce an antinociceptive effect, while morphine alone induced antinociceptive tolerance and down-regulation of spinal glutamate transporters (GLAST, GLT-1, and EAAC1) in the rat spinal cord dorsal horn. Co-administration of amitriptyline with morphine attenuated morphine tolerance and up-regulated GLAST and GLT-1 expression. On day 5, morphine challenge (10 microg/10 microl) resulted in a significant increase in levels of the excitatory amino acids (EAAs), aspartate and glutamate, in CSF dialysates in morphine-tolerant rats. Amitriptyline co-infusion not only markedly suppressed this morphine-evoked EAA release, but also preserved the antinociceptive effect of acute morphine challenge at the end of infusion. Glial cells activation and increased cytokine expression (TNFalpha, IL-1beta, and IL-6) in the rat spinal cord were induced by the 5-day morphine infusion and these neuroimmune responses were also prevented by amitriptyline co-infusion. These results show that amitriptyline not only attenuates morphine tolerance, but also preserves its antinociceptive effect. The mechanisms involved may include: (a) inhibition of pro-inflammatory cytokine expression, (b) prevention of glutamate transporter down-regulation, and even up-regulation of glial GTs GLAST and GLT-1 expression, with (c) attenuation of morphine-evoked EAA release following continuous long-term morphine infusion.

These results indicated that the anti-inflammatory effects of these compounds were mediated, at least partly, through the suppression of chemical mediators released from mast cells and neutrophils.

We evaluated the prophylactic effect of small-dose dexamethasone (5 mg) on postoperative nausea and vomiting (PONV) in patients undergoing laparoscopic cholecystectomy. Tropisetron (2 mg) and saline served as controls. We found that dexamethasone 5 mg (IV) significantly reduced the incidence of PONV in these patients, and, at this dose, dexamethasone was as effective as tropisetron and was more effective than placebo.