Using b-tagging to enhance the SUSY reach of the CERN Large Hadron Collider

Assuming that supersymmetry is realized with parameters in the hyperbolic branch/focus point (HB/FP) region of the minimal supergravity (mSUGRA) model, we show that by searching for multijet + missing E_T events with tagged b jets the reach of experiments at the LHC may be extended by as much as 20% from current projections. The reason for this is that gluino decays to third generation quarks are enhanced because the lightest neutralino has substantial higgsino components. Although we were motivated to perform this analysis because the HB/FP region is compatible with the recent determination of the relic density of cold dark matter, our considerations may well have a wider applicability since decays of gluinos to third generation quarks are favoured in a wide variety of models.Comment: 16 pages, 1 figur

Covariant Lagrangian Formulation of Chern-Simons and BF Theories

We investigate the covariant formulation of Chern-Simons theories in a general odd dimension which can be obtained by introducing a vacuum connection field as a reference. Field equations, Noether currents and superpotentials are computed so that results are easily compared with the well-known results in dimension 3. Finally we use this covariant formulation of Chern-Simons theories to investigate their relation with topological BF theories.Comment: 23 pages, refs. adde

Rapid switching between transdermal fentanyl and methadone in cancer patients

Purpose The aim of this study was to examine the clinical effects of switching from transdermal (TTS)fentanyl to methadone, or vice versa, in patients with a poor response to the previous opioid. Patients and Methods A prospective study was carried out on 31 patients who switched from TTS fentanyl to oral methadone, or vice versa, because of poor opioid response. A fixed conversion ratio of fentanyl to methadone of 1:20 was started and assisted by rescue doses of opioids, and then doses were changed according to clinical response. Pain and symptom intensity, expressed as distress score, were recorded before switching doses of the two opioids and after subsequent doses. The number of changes of the daily doses, time to achieve stabilization, and hospital stay were also recorded. Results Eighteen patients were switched from TTS fentanyl to methadone, and seven patients were switched from methadone to TTS fentanyl. A significant decrease in pain and symptom intensity, expressed as symptom distress score, was found within 24 hours after switching took place in both directions. Unsuccessful switching occurred in six patients, who were subsequently treated with an alternative therapy. Conclusion A rapid switching using an initial fixed ratio of fentanyl to methadone of 1:20 is an effective method to improve the balance between analgesia and adverse effects in cancer patients with poor response to the previous opioid. No relationship between the final opioid dose and the dose of the previous opioid has been found

Prevalence of opioid-related dysuria in patients with advanced cancer having pain.

The aim of this study was to assess the prevalence of opioid-induced dysuria in patients with advanced cancer having pain and to evaluate the possible factors associated. A consecutive sample of cancer patients admitted to an acute pain relief and palliative care unit during 8 months was surveyed. Most patients (147, 86.5%) were receiving opioids at admission. The mean age was 65.1 (SD 12.2) and 106 patients were males. Twenty-five patients presented with dysuria at admission (of which 22 were taking opioids, 14.9%). Eleven patients were inserted a bladder catheter at admission for urine monitoring and 18 patients had urinary incontinence. During admission, 31 patients presented dysuria (19% of population was taking opioids). The prevalence of dysuria was more frequent in males, in patients presenting pelvic masses or who had pelvic surgery, and patients with neurological deficits. Opioid switching during admission was correlated to the occurrence of dysuria. Patients with chronic cancer pain receiving opioid therapy present a prevalence of bladder dysfunction of about 15%, which is influenced by several concomitant factors. Given the complex clinical picture of advanced cancer patients, further studies should be performed to explore the presence of dysuria in patients with no pain and not receiving opioids to know the real weight of opioid therapy with respect to other variables.</jats:p

Opioid-induced or pain relief-reduced symptoms in advanced cancer patients?

Background: While opioids in increasing doses may produce adverse effects, the same adverse effects may be associated with poor pain control. Moreover, in the clinical setting symptomatic treatment and illness may balance the outcome of opioid titration. Some adverse effects may tend to disappear continuing the treatment in a long-term period. Aims: The aim of this study was to monitor the effects of a rapid opioid titration combined with symptomatic treatment in patients with poor relief and to monitor these changes in the following period of 20 days. Methods: A consecutive sample of 35 patients admitted to an acute Pain Relief and Palliative Care Unit were titrated with opioids, according to a department policy, allowing administration of parenteral opioids to assist opioid titration with oral or transdermal opioids. Results: Thirty-three patients were followed up for the period of the study. Pain was adequately controlled and doses were opioid doses were stable after a mean of 40 h. Opioid escalation index (OEI) was extremely high initially, and then progressively declined at the following study intervals. Weakness and nausea and vomiting did not change, as well as confusion and appetite. Drowsiness, constipation and dry mouth significantly increased and then did not change, although a significant decrease in drowsiness was subsequently observed. Well-being improved some weeks after opioid stabilization. In multivariate analysis, drowsiness and dry mouth were correlated to opioid doses. Conclusion: The effects reported were often due to multiple causes. A rapid decrease in pain intensity induced by rapid opioid titration does not produce changes in weakness, nausea and vomiting, appetite. While constipation appears the most relevant problem,resistant to common symptomatic treatment, drowsiness initially produced by acute opioid dose increase and the achievement of pain relief, tends to spontaneously decrease, probably as the result of late tolerance. Improved well-being may be the late positive effect of pain relief, also influenced by the setting of home care

The use of opioids in the last week of life in an acute palliative care unit.

The aim of this survey was to assess the opioid use in the last week of life of cancer patients admitted at an acute palliative care unit. From a consecutive sample of patients surveyed for a period of one year, patients who died in the unit were selected. Type of opioid, route of administration, and doses were recorded one week before death (or at admission time if the interval admission-death was less than one week) (-7), and on the day of death (Tend). Seventy-seven patients died in the unit in the period taken into consideration (12.4%). Oral morphine equivalents were 170 mg/day and 262 mg/day at -7 and Tend, respectively. Patients were receiving transdermal drugs or intravenous morphine at Tend, with a trend in the use of intravenous morphine at Tend (p=0.07). Intravenous morphine was more frequently used in sedated patients at Tend (p=0.015).No differences in age, gender, opioid doses, and OEI were found among opioids used. In patients who were sedated doses of opioids were significantly increased (p=0.012). In the last week of life intravenous morphine is the preferred modality to deliver opioids in an acute palliative care unit. Doses increases prevalently observed in sedated patients were performed before starting sedation with the purpose to treat concomitant distressing symptoms, such as dyspnoea