Radiation recoil from highly distorted black holes

We present results from numerical evolutions of single black holes distorted by axisymmetric, but equatorially asymmetric, gravitational (Brill) waves. Net radiated energies, apparent horizon embeddings, and recoil velocities are shown for a range of Brill wave parameters, including both even and odd parity distortions of Schwarzschild black holes. We find that a wave packet initially concentrated on the black hole throat, a likely model also for highly asymmetric stellar collapse and late stage binary mergers, can generate a maximum recoil velocity of about 150 (23) km/sec for even (odd) parity perturbations, significantly less than that required to eject black holes from galactic cores.Comment: 15 pages, 8 figure

Cost-effectiveness analysis of cetuximab/irinotecan vs active/best supportive care for the treatment of metastatic colorectal cancer patients who have failed previous chemotherapy treatment

The treatment of colorectal cancer is rapidly becoming a significant financial burden to health-care systems within economically developed nations. A current challenge for oncologists and health-care payers is to integrate new, often high-cost, biologic therapies into clinical practice. Inherent to this process is the consideration of cost-effectiveness. The aim of this study was to compare the cost-effectiveness of cetuximab plus irinotecan with an appropriate comparator from a National Health Service (NHS) perspective. This economic evaluation is a trial-based study of cetuximab vs active/best supportive care. Effectiveness estimates for the treatment groups were modelled from key clinical trials. Cunningham et al (2004) compared cetuximab/irinotecan with cetuximab monotherapy; Cunningham et al (1998) compared irinotecan monotherapy in a second-line setting with supportive care. Modelling was necessary owing to an absence of head-to-head clinical trial data of cetuximab/irinotecan vs current standard care. Costs were calculated for the study drugs received, associated administration, palliative chemotherapy for patients in the standard care arm and other nonchemotherapy resources. The discounted life-expectancy of patients treated with cetuximab/irinotecan was 0.91 life-years, and 0.47 discounted life-years for patients receiving active/best supportive care. Patients treated with cetuximab/irinotecan accumulated mean additional costs of £18 901 per patient relative to the comparator arm, with £11 802 attributable to cetuximab. The incremental cost per life-year gained with cetuximab/irinotecan therapy compared with active/best supportive care was £42 975. The incremental cost per quality adjusted life-year gained was £57 608. The incremental cost per life-year gained for cetuximab/irinotecan is relatively high compared with other health-care interventions. However, this result should be considered in the context of a number of factors specific to the treated patient population

Cetuximab and irinotecan as third-line therapy in advanced colorectal cancer patients: a single centre phase II trial

The epidermal growth factor receptor (EGFR), which participates in signalling pathways that are deregulated in cancer cells, is frequently mutated in colorectal-cancer cells. Cetuximab is a monoclonal antibody that specifically blocks the EGFR. We evaluated the efficacy of cetuximab in weekly combination with irinotecan in metastatic colorectal cancer patients refractory to previous treatments based on oxaliplatin or irinotecan. We included 55 heavily pretreated patients (colon/rectum: 34/11, M/F: 16/29, median age 63 years, range: 27–79) whose disease had progressed during or within an oxaliplatin-based first-line chemotherapy and a irinotecan-based second-line regimen. Patients were followed for tumour response and were also evaluated for the time to tumour progression, and safety of treatment. Cetuximab was given at an initial dose of 400 mg m−2, followed by weekly infusions of 250 mg m−2. Irinotecan was administered weekly at the dose of 90 mg m−2. All patients were assessable for treatment efficacy and safety response rate was 25.4% (95% CI: 21.7–39.6%); 38.2% (95 CI: 18.6–39.8%) of patients showed a disease stability as the best response. As a consequence, the overall tumour control rate was 63.6% (95% CI: 46.4–70.6%). The median time to progression was 4.7 months (95% CI: 2.5–7.1 months) and the median survival time was 9.8 months (95% CI: 3.9–10.1 months). The most common G3-4 noncutaneous side toxicities were: diarrhoea (16.4%), fatigue (12.7%) and stomatitis (7.3%). 89.1% of patients developed skin toxicity and 32.6% of cases was of grade 3–4. No allergic reactions were identified at any courses in any patients. Fever was documented in 27.3% of patients and was most commonly recorded after the first administration. Cetuximab has clinically significant activity even in heavily pretreated colorectal cancer patients progressed after both oxaliplatin and irinotecan-based chemotherapy regimens

Emerging Infectious Disease leads to Rapid Population Decline of Common British Birds

Emerging infectious diseases are increasingly cited as threats to wildlife, livestock and humans alike. They can threaten geographically isolated or critically endangered wildlife populations; however, relatively few studies have clearly demonstrated the extent to which emerging diseases can impact populations of common wildlife species. Here, we report the impact of an emerging protozoal disease on British populations of greenfinch Carduelis chloris and chaffinch Fringilla coelebs, two of the most common birds in Britain. Morphological and molecular analyses showed this to be due to Trichomonas gallinae. Trichomonosis emerged as a novel fatal disease of finches in Britain in 2005 and rapidly became epidemic within greenfinch, and to a lesser extent chaffinch, populations in 2006. By 2007, breeding populations of greenfinches and chaffinches in the geographic region of highest disease incidence had decreased by 35% and 21% respectively, representing mortality in excess of half a million birds. In contrast, declines were less pronounced or absent in these species in regions where the disease was found in intermediate or low incidence. Also, populations of dunnock Prunella modularis, which similarly feeds in gardens, but in which T. gallinae was rarely recorded, did not decline. This is the first trichomonosis epidemic reported in the scientific literature to negatively impact populations of free-ranging non-columbiform species, and such levels of mortality and decline due to an emerging infectious disease are unprecedented in British wild bird populations. This disease emergence event demonstrates the potential for a protozoan parasite to jump avian host taxonomic groups with dramatic effect over a short time period

Vi polysaccharide and conjugated vaccines afford similar early, IgM or IgG-independent control of infection but boosting with conjugated Vi vaccines sustains the efficacy of immune responses

IntroductionVaccination with Vi capsular polysaccharide (Vi-PS) or protein-Vi typhoid conjugate vaccine (TCV) can protect adults against Salmonella Typhi infections. TCVs offer better protection than Vi-PS in infants and may offer better protection in adults. Potential reasons for why TCV may be superior in adults are not fully understood.Methods and resultsHere, we immunized wild-type (WT) mice and mice deficient in IgG or IgM with Vi-PS or TCVs (Vi conjugated to tetanus toxoid or CRM197) for up to seven months, with and without subsequent challenge with Vi-expressing Salmonella Typhimurium. Unexpectedly, IgM or IgG alone were similarly able to reduce bacterial burdens in tissues, and this was observed in response to conjugated or unconjugated Vi vaccines and was independent of antibody being of high affinity. Only in the longer-term after immunization (>5 months) were differences observed in tissue bacterial burdens of mice immunized with Vi-PS or TCV. These differences related to the maintenance of antibody responses at higher levels in mice boosted with TCV, with the rate of fall in IgG titres induced to Vi-PS being greater than for TCV.DiscussionTherefore, Vi-specific IgM or IgG are independently capable of protecting from infection and any superior protection from vaccination with TCV in adults may relate to responses being able to persist better rather than from differences in the antibody isotypes induced. These findings suggest that enhancing our understanding of how responses to vaccines are maintained may inform on how to maximize protection afforded by conjugate vaccines against encapsulated pathogens such as S. Typhi.</p

Testing of an oral dosing technique for double-crested cormorants, \u3ci\u3ePhalacocorax auritus\u3c/i\u3e, laughing gulls, \u3ci\u3eLeucophaeus atricilla\u3c/i\u3e, homing pigeons, \u3ci\u3eColumba livia\u3c/i\u3e, and western sandpipers, \u3ci\u3eCalidris mauri\u3c/i\u3e, with artificially weather MC252 oil

Scoping studies were designed to determine if double-crested cormorants (Phalacocorax auritus), laughing gulls (Leucophaues atricilla), homing pigeons (Columba livia) and western sandpipers (Calidris mauri) that were gavaged with a mixture of artificially weathered MC252 oil and food for either a single day or 4–5 consecutive days showed signs of oil toxicity. Where volume allowed, samples were collected for hematology, plasma protein electrophoresis, clinical chemistry and electrolytes, oxidative stress and organ weigh changes. Double-crested cormorants, laughing gulls and western sandpipers all excreted oil within 30 min of dose, while pigeons regurgitated within less than one hour of dosing. There were species differences in the effectiveness of the dosing technique, with double-crested cormorants having the greatest number of responsive endpoints at the completion of the trial. Statistically significant changes in packed cell volume, white cell counts, alkaline phosphatase, alanine aminotransferase, creatine phosphokinase, gamma glutamyl transferase, uric acid, chloride, sodium, potassium, calcium, total glutathione, glutathione disulfide, reduced glutathione, spleen and liver weights were measured in double-crested cormorants. Homing pigeons had statistically significant changes in creatine phosphokinase, total glutathione, glutathione disulfide, reduced glutathione and Trolox equivalents. Laughing gulls exhibited statistically significant decreases in spleen and kidney weight, and no changes were observed in any measurement endpoints tested in western sandpipers

Antimonial Resistance in Leishmania donovani Is Associated with Increased In Vivo Parasite Burden

Leishmania donovani is an intracellular protozoan parasite that causes visceral leishmaniasis (VL). Antimonials (SSG) have long been the first-line treatment against VL, but have now been replaced by miltefosine (MIL) in the Indian subcontinent due to the emergence of SSG-resistance. Our previous study hypothesised that SSG-resistant L. donovani might have increased in vivo survival skills which could affect the efficacy of other treatments such as MIL. The present study attempts to validate these hypotheses. Fourteen strains derived from Nepalese clinical isolates with documented SSG-susceptibility were infected in BALB/c mice to study their survival capacity in drug free conditions (non-treated mice) and in MIL-treated mice. SSG-resistant parasites caused a significant higher in vivo parasite load compared to SSG-sensitive parasites. However, this did not seem to affect the strains' response to MIL-treatment since parasites from both phenotypes responded equally well to in vivo MIL exposure. We conclude that there is a positive association between SSG-resistance and in vivo survival skills in our sample of L. donovani strains which could suggest a higher virulence of SSG-R strains compared to SSG-S strains. These greater in vivo survival skills of SSG-R parasites do not seem to directly affect their susceptibility to MIL. However, it cannot be excluded that repeated MIL exposure will elicit different adaptations in these SSG-R parasites with superior survival skills compared to the SSG-S parasites. Our results therefore highlight the need to closely monitor drug efficacy in the field, especially in the context of the Kala-azar elimination programme ongoing in the Indian subcontinent

Simple Metals at High Pressure

In this lecture we review high-pressure phase transition sequences exhibited by simple elements, looking at the examples of the main group I, II, IV, V, and VI elements. General trends are established by analyzing the changes in coordination number on compression. Experimentally found phase transitions and crystal structures are discussed with a brief description of the present theoretical picture.Comment: 22 pages, 4 figures, lecture notes for the lecture given at the Erice course on High-Pressure Crystallography in June 2009, Sicily, Ital