Brown adipose tissue thermogenesis does not explain the intra-administration hyperthermic sign-reversal induced by serial administrations of 60% nitrous oxide to rats.

Initial administration of ≥60% nitrous oxide (N2O) to rats promotes hypothermia primarily by increasing whole-body heat loss. We hypothesized that the drug promotes heat loss via the tail and might initially inhibit thermogenesis via brown adipose tissue (BAT), major organs of thermoregulation in rodents. Following repeated administrations, N2O inhalation evokes hyperthermia underlain by increased whole-body heat production. We hypothesized that elevated BAT thermogenesis plays a role in this thermoregulatory sign reversal. Using dual probe telemetric temperature implants and infrared (IR) thermography, we assessed the effects of nine repeated 60% N2O administrations compared to control (con) administrations on core temperature, BAT temperature, lumbar back temperature and tail temperature. Telemetric core temperature, telemetric BAT temperature, and IR BAT temperature were reduced significantly during initial 60% N2O inhalation (p≤0.001 compared to con). IR thermography revealed that acute N2O administration unexpectedly reduced tail temperature (p=0.0001) and also inhibited IR lumbar temperature (p<0.0001). In the 9th session, N2O inhalation significantly increased telemetric core temperature (p=0.007) indicative of a hyperthermic sign reversal, yet compared to control administrations, telemetric BAT temperature (p=0.86), IR BAT temperature (p=0.85) and tail temperature (p=0.47) did not differ significantly. Thus, an initial administration of 60% N2O at 21°C may promote hypothermia via reduced BAT thermogenesis accompanied by tail vasoconstriction as a compensatory mechanism to limit body heat loss. Following repeated N2O administrations rats exhibit a hyperthermic core temperature but a normalized BAT temperature, suggesting induction of a hyperthermia-promoting thermogenic adaptation of unknown origin.

Efficacy and safety of sorafenib in patients with advanced hepatocellular carcinoma according to baseline status: subset analyses of the phase III Sorafenib Asia-Pacific trial.

BACKGROUND: The phase III Sorafenib Asia-Pacific (AP) trial-conducted in China, Taiwan and South Korea - confirmed that sorafenib improves overall survival (OS) and is safe for patients with advanced hepatocellular carcinoma (HCC). We performed a series of exploratory subset analyses to determine whether baseline status affected response to sorafenib. METHODS: In the Sorafenib AP trial, 226 patients with well-preserved liver function (>95% Child-Pugh A) were randomised 2:1 to sorafenib 400mg bid or matching placebo. Subanalyses were based on aetiology (hepatitis B virus present/absent); tumour burden (macroscopic vascular invasion and/or extrahepatic spread present/absent); presence or absence of either lung or lymph node metastasis at baseline, Eastern Cooperative Oncology Group performance status (0, 1-2); serum concentrations of alanine aminotransferase/aspartate aminotransferase (normal, mildly elevated, moderately elevated), alpha-fetoprotein (normal/elevated) and total bilirubin (normal/elevated); and whether or not there was a history of hepatectomy or transarterial chemoembolisation/embolisation. Subgroup assessments included OS, time to progression (TTP), disease control rate and safety. FINDINGS: Sorafenib consistently improved both median OS and median TTP, compared with placebo (range of hazard ratios (HR), 0.32-0.87 and 0.31-0.75, respectively). The most common grade 3/4 adverse events were hand-foot skin reaction, diarrhoea and fatigue, the incidence of which was similar between subgroups. INTERPRETATION: The efficacy and safety profiles of sorafenib in the subpopulations described were comparable with those in the overall study population. These exploratory analyses suggest that sorafenib is effective for patients from the AP region with advanced HCC, irrespective of baseline status.

Efficacy and safety of sorafenib in patients in the Asia-Pacific region with advanced hepatocellular carcinoma: a phase III randomised, double-blind, placebo-controlled trial.

BACKGROUND: Most cases of hepatocellular carcinoma occur in the Asia-Pacific region, where chronic hepatitis B infection is an important aetiological factor. Assessing the efficacy and safety of new therapeutic options in an Asia-Pacific population is thus important. We did a multinational phase III, randomised, double-blind, placebo-controlled trial to assess the efficacy and safety of sorafenib in patients from the Asia-Pacific region with advanced (unresectable or metastatic) hepatocellular carcinoma. METHODS: Between Sept 20, 2005, and Jan 31, 2007, patients with hepatocellular carcinoma who had not received previous systemic therapy and had Child-Pugh liver function class A, were randomly assigned to receive either oral sorafenib (400 mg) or placebo twice daily in 6-week cycles, with efficacy measured at the end of each 6-week period. Eligible patients were stratified by the presence or absence of macroscopic vascular invasion or extrahepatic spread (or both), Eastern Cooperative Oncology Group performance status, and geographical region. Randomisation was done centrally and in a 2:1 ratio by means of an interactive voice-response system. There was no predefined primary endpoint; overall survival, time to progression (TTP), time to symptomatic progression (TTSP), disease control rate (DCR), and safety were assessed. Efficacy analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00492752. FINDINGS: 271 patients from 23 centres in China, South Korea, and Taiwan were enrolled in the study. Of these, 226 patients were randomly assigned to the experimental group (n=150) or to the placebo group (n=76). Median overall survival was 6.5 months (95% CI 5.56-7.56) in patients treated with sorafenib, compared with 4.2 months (3.75-5.46) in those who received placebo (hazard ratio [HR] 0.68 [95% CI 0.50-0.93]; p=0.014). Median TTP was 2.8 months (2.63-3.58) in the sorafenib group compared with 1.4 months (1.35-1.55) in the placebo group (HR 0.57 [0.42-0.79]; p=0.0005). The most frequently reported grade 3/4 drug-related adverse events in the 149 assessable patients treated with sorafenib were hand-foot skin reaction (HFSR; 16 patients [10.7%]), diarrhoea (nine patients [6.0%]), and fatigue (five patients [3.4%]). The most common adverse events resulting in dose reductions were HFSR (17 patients [11.4%]) and diarrhoea (11 patients [7.4%]); these adverse events rarely led to discontinuation. INTERPRETATION: Sorafenib is effective for the treatment of advanced hepatocellular carcinoma in patients from the Asia-Pacific region, and is well tolerated. Taken together with data from the Sorafenib Hepatocellular Carcinoma Assessment Randomised Protocol (SHARP) trial, sorafenib seems to be an appropriate option for the treatment of advanced hepatocellular carcinoma.