The Comet Interceptor Mission

Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA's F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum Δ V capability of 600  ms - 1 . Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes - B1, provided by the Japanese space agency, JAXA, and B2 - that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission's science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule.

Contribution of SARS-CoV-2 RNA shedding routes to RNA loads in wastewater

A portion of those infected with SARS-CoV-2 shed the virus and its genetic material in respiratory fluids, saliva, urine, and stool, thus giving the potential to monitor for infections via wastewater. Wastewater surveillance efforts to date have largely assumed that stool shedding has been the primary source of SARS-CoV-2 RNA signal; however, there are increasing questions about the possible contribution of other shedding routes, with implications for wastewater surveillance design and feasibility. In this study we used clinical SARS-CoV-2 RNA shedding data and a Monte Carlo framework to assess the relative contribution of various shedding routes on SARS-CoV-2 RNA loads in wastewater. Stool shedding dominated total SARS-CoV-2 RNA load for community-level surveillance, with mean contributions more than two orders of magnitude greater than other shedding routes. However, RNA loads were more nuanced when considering building-level monitoring efforts designed to identify a single infected individual, where any shedding route could plausibly contribute a detectable signal. The greatest source of model variability was viral load in excreta, suggesting that future modeling efforts may be improved by incorporating specific modeling scenarios with precise SARS-CoV-2 shedding data, and beyond that wastewater surveillance must continue to account for large variability during data analysis and reporting. Importantly, the findings imply that wastewater surveillance at finer spatial scales is not entirely dependent on shedding via feces for sensitive detection of infections thus enlarging the potential use cases of wastewater as a non-intrusive surveillance methodology.

Reduction in Accumulation of Plaque, Stain, and Calculus in Dogs by Dietary Means

We conducted 215 evaluations for plaque, stain, and calculus in 120 dogs at two research sites. Dogs were balanced in groups of five according to baseline plaque index scores; groups were randomly assigned to treatment or control dietary regimens. Dental cleanings were done on Day 0. Dogs in the treatment group were fed a food formulated to reduce accumulation of plaque, stain, and calculus. Control group dogs were fed a commercially available dry dog food. No other foods, treats, or snacks were given to either group. We graded 22 teeth for plaque accumulation on Day 7 and for stain and calculus accumulation on Day 21. Six trials were conducted and the results reported as a combined mean for all treatment and control groups. Dogs fed the treatment food had significantly less plaque, stain, and calculus accumulation (p=0.001) than dogs fed the control food. Plaque, stain, and calculus accumulation can be reduced by dietary means.

Association of Periodontal Disease and Histologic Lesions in Multiple Organs from 45 Dogs

Forty-five mixed breed dogs were evaluated for the presence and extent of periodontal disease. Histopathology was performed on samples of lung, myocardium, liver, kidney, tonsil, spleen, submandibular lymph node and tracheobronchial lymph node. Mitral valves were evaluated grossly. Statistical analysis was used to determine if there was a relationship between the extent of periodontal disease and histopathologic changes in the tissues examined. In the forty-five dogs studied, an association was found between periodontal disease and histopathologic changes in kidney, myocardium (papillary muscle), and liver.

Tildrakizumab efficacy and impact on quality of life up to 52 weeks in patients with moderate-to-severe psoriasis: a pooled analysis of two randomized controlled trials

BACKGROUND

Two randomized controlled trials (reSURFACE 1 and 2) have demonstrated the effectiveness of tildrakizumab, a high-affinity, humanized, IgG1κ, anti-interleukin-23 monoclonal antibody, for treating moderate-to-severe plaque psoriasis in the first 28 weeks.

OBJECTIVES

To examine the efficacy of tildrakizumab and its impact on quality of life (QoL) in patients with different levels of week-28 Psoriasis Area and Severity Index (PASI) improvement.

METHODS

Patients treated with tildrakizumab 100 mg or 200 mg from baseline to week 28 were pooled from reSURFACE 1 and reSURFACE 2 and classified into five mutually exclusive week-28 PASI improvement groups for each dose: PASI 0-49, 50-74, 75-89, 90-99 and 100. Mean PASI improvement and Dermatology Life Quality Index (DLQI) 0/1 over time were examined for each group.

RESULTS

Of 1156 patients, 575 were in the 100-mg and 578 in the 200-mg cohorts, respectively. At week 28, 8.3%, 14.3%, 23.8%, 30.4% and 23.1% in the 100-mg and 4.0%, 18.1%, 19.6%, 29.1% and 29.3% in the 200-mg cohort achieved PASI < 50, 50-74, 75-89, 90-99 and 100, respectively. Patients with PASI < 50 at week 28 could be identified as early as week 8, and those with week-28 PASI ≥ 90 had approximately 50% PASI improvement by week 4. Among patients achieving PASI > 50 at week 28 who continued the same dose of tildrakizumab to week 52, mean PASI improvement was maintained or improved over time. Similar results were observed for both doses. Higher proportions of patients achieved DLQI 0/1 in higher week-28 PASI groups, and DLQI 0/1 was maintained or improved to week 52. However, not all patients with PASI 100 had DLQI 0/1.

CONCLUSION

Patients unlikely to respond to tildrakizumab could be identified by week 8, and those likely to achieve a PASI ≥ 90 response could be identified as early as week 4. Week-28 PASI improvement level correlated with QoL improvement.

Two independent and primitive envelopes of the bilobate nucleus of comet 67P

The factors shaping cometary nuclei are still largely unknown, but could be the result of concurrent effects of evolutionary and primordial processes. The peculiar bilobed shape of comet 67P/Churyumov-Gerasimenko may be the result of the fusion of two objects that were once separate or the result of a localized excavation by outgassing at the interface between the two lobes. Here we report that the comet's major lobe is enveloped by a nearly continuous set of strata, up to 650 metres thick, which are independent of an analogous stratified envelope on the minor lobe. Gravity vectors computed for the two lobes separately are closer to perpendicular to the strata than those calculated for the entire nucleus and adjacent to the neck separating the two lobes. Therefore comet 67P/Churyumov-Gerasimenko is an accreted body of two distinct objects with 'onion-like' stratification, which formed before they merged. We conclude that gentle, low-velocity collisions occurred between two fully formed kilometre-sized cometesimals in the early stages of the Solar System. The notable structural similarities between the two lobes of comet 67P/Churyumov-Gerasimenko indicate that the early-forming cometesimals experienced similar primordial stratified accretion, even though they formed independently.

Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse

Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts. Alternative mechanisms like explosive activity have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface.

Practices in prescribing protein substitutes for PKU in Europe: No uniformity of approach

BACKGROUND

There appears little consensus concerning protein requirements in phenylketonuria (PKU).

METHODS

A questionnaire completed by 63 European and Turkish IMD centres from 18 countries collected data on prescribed total protein intake (natural/intact protein and phenylalanine-free protein substitute [PS]) by age, administration frequency and method, monitoring, and type of protein substitute. Data were analysed by European region using descriptive statistics.

RESULTS

The amount of total protein (from PS and natural/intact protein) varied according to the European region. Higher median amounts of total protein were prescribed in infants and children in Northern Europe (n=24 centres) (infants <1 year, >2-3g/kg/day; 1-3 years of age, >2-3 g/kg/day; 4-10 years of age, >1.5-2.5 g/kg/day) and Southern Europe (n=10 centres) (infants <1 year, 2.5 g/kg/day, 1-3 years of age, 2 g/kg/day; 4-10 years of age, 1.5-2 g/kg/day), than by Eastern Europe (n=4 centres) (infants <1 year, 2.5 g/kg/day, 1-3 years of age, >2-2.5 g/kg/day; 4-10 years of age, >1.5-2 g/kg/day) and with Western Europe (n=25 centres) giving the least (infants <1 year, >2-2.5 g/kg/day, 1-3 years of age, 1.5-2 g/kg/day; 4-10 years of age, 1-1.5 g/kg/day). Total protein prescription was similar in patients aged >10 years (1-1.5 g/kg/day) and maternal patients (1-1.5 g/kg/day).

CONCLUSIONS

The amounts of total protein prescribed varied between European countries and appeared to be influenced by geographical region. In PKU, all gave higher than the recommended 2007 WHO/FAO/UNU safe levels of protein intake for the general population.

Dietary management of urea cycle disorders: European practice

BACKGROUND

There is no published data comparing dietary management of urea cycle disorders (UCD) in different countries.

METHODS

Cross-sectional data from 41 European Inherited Metabolic Disorder (IMD) centres (17 UK, 6 France, 5 Germany, 4 Belgium, 4 Portugal, 2 Netherlands, 1 Denmark, 1 Italy, 1 Sweden) was collected by questionnaire describing management of patients with UCD on prescribed protein restricted diets.

RESULTS

Data for 464 patients: N-acetylglutamate synthase (NAGS) deficiency, n=10; carbamoyl phosphate synthetase (CPS1) deficiency, n=29; ornithine transcarbamoylase (OTC) deficiency, n=214; citrullinaemia, n=108; argininosuccinic aciduria (ASA), n=80; arginase deficiency, n=23 was reported. The majority of patients (70%; n=327) were aged 0-16y and 30% (n=137) >16y. Prescribed median protein intake/kg body weight decreased with age with little variation between disorders. The UK tended to give more total protein than other European countries particularly in infancy. Supplements of essential amino acids (EAA) were prescribed for 38% [n=174] of the patients overall, but were given more commonly in arginase deficiency (74%), CPS (48%) and citrullinaemia (46%). Patients in Germany (64%), Portugal (67%) and Sweden (100%) were the most frequent users of EAA. Only 18% [n=84] of patients were prescribed tube feeds, most commonly for CPS (41%); and 21% [n=97] were prescribed oral energy supplements.

CONCLUSIONS

Dietary treatment for UCD varies significantly between different conditions, and between and within European IMD centres. Further studies examining the outcome of treatment compared with the type of dietary therapy and nutritional support received are required.

Dietary practices in pyridoxine non-responsive homocystinuria: a European survey

BACKGROUND

Within Europe, the management of pyridoxine (B6) non-responsive homocystinuria (HCU) may vary but there is limited knowledge about treatment practice.

AIM

A comparison of dietetic management practices of patients with B6 non-responsive HCU in European centres.

METHODS

A cross-sectional audit by questionnaire was completed by 29 inherited metabolic disorder (IMD) centres: (14 UK, 5 Germany, 3 Netherlands, 2 Switzerland, 2 Portugal, 1 France, 1 Norway, 1 Belgium).

RESULTS

181 patients (73% >16 years of age) with HCU were identified. The majority (66%; n=119) were on dietary treatment (1-10 years, 90%; 11-16 years, 82%; and >16 years, 58%) with or without betaine and 34% (n=62) were on betaine alone. The median natural protein intake (g/day) on diet only was, by age: 1-10 years, 12 g; 11-16 years, 11 g; and >16 years, 45 g. With diet and betaine, median natural protein intake (g/day) by age was: 1-10 years, 13 g; 11-16 years, 20 g; and >16 years, 38 g. Fifty-two percent (n=15) of centres allocated natural protein by calculating methionine rather than a protein exchange system. A methionine-free l-amino acid supplement was prescribed for 86% of diet treated patients. Fifty-two percent of centres recommended cystine supplements for low plasma concentrations. Target treatment concentrations for homocystine/homocysteine (free/total) and frequency of biochemical monitoring varied.

CONCLUSION

In B6 non-responsive HCU the prescription of dietary restriction by IMD centres declined with age, potentially associated with poor adherence in older patients. Inconsistencies in biochemical monitoring and treatment indicate the need for international consensus guidelines.

Pain assessment during conscious sedation for cervical cancer high-dose-rate brachytherapy

BACKGROUND

This observational study set out to evaluate the effectiveness of conscious sedation anesthesia for pain control during high-dose-rate (hdr) brachytherapy using a ring-and-tandem applicator system for patients with cervical cancer.

METHODS

At the time of initiation of the hdr cervical cancer brachytherapy program at our institution, patients received a detailed symptom assessment during the procedures. Brachytherapy was carried out using a Smit sleeve, together with a ring-and-tandem applicator. Midazolam and an opioid-hydromorphone, morphine, or fentanyl-were the main agents used to achieve conscious sedation.

RESULTS

From January 2009 to October 2010, 20 patients (median age: 45 years) underwent 57 procedures. All patients received chemoradiation with curative intent. The median duration of the procedures was 1.4 hours, and no significant cardiovascular events were noted. The total dose of intravenous midazolam used ranged from 0.5 mg to 8.5 mg (median: 2.5 mg). The total dose of intravenous morphine equivalent used ranged from 2.5 mg to 60 mg (median: 8 mg). The mean and median pain scores during the procedures were 1.4 and 1.1 respectively. Brief moments of moderate to severe incidental pain were noted at the time of certain events during the procedure-specifically during insertion of the ring-and-tandem applicator. The maximal pain score during the entire procedure ranged from 0 to 10 (median: 4.7). The period of recovery from conscious sedation was relatively brief (median discharge time: 1 hour).

CONCLUSIONS

We were able to demonstrate that patients undergoing hdr brachytherapy for cervical cancer can achieve good pain control with conscious sedation.

Permanent draft genome sequence of Comamonas testosteroni KF-1

Comamonas testosteroni KF-1 is a model organism for the elucidation of the novel biochemical degradation pathways for xenobiotic 4-sulfophenylcarboxylates (SPC) formed during biodegradation of synthetic 4-sulfophenylalkane surfactants (linear alkylbenzenesulfonates, LAS) by bacterial communities. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 6,026,527 bp long chromosome (one sequencing gap) exhibits an average G+C content of 61.79% and is predicted to encode 5,492 protein-coding genes and 114 RNA genes.

Living with the BRCA1 and BRCA2 genetic mutation: learning how to adapt to a virtual chronic illness

The objective of this study was to understand how women living with the BRCA1 and BRCA2 genetic mutation adapt to this life transition and to identify the main adaptive tasks. A qualitative inquiry inspired by grounded theory revealed that participants cognitively appraised their test result in the same manner as women who have been diagnosed with breast cancer. Consequently, participants had to adapt to a condition that they perceived as a chronic illness. The following three main tasks were identified: Physical Task: Attempting to Limit the Impact of the Test Result, Psychological Task: Living with Uncertainty, and Social Task: Finding Effective Support. In conclusion, although these women live with the possibility of developing breast cancer, their experiences mirror those of individuals living with a chronic illness, and they must therefore adapt accordingly in a physical, psychological, and social manner.

Living with the BRCA genetic mutation: an uncertain conclusion to an unending process

Women carrying a BRCA1 or BRCA2 genetic mutation have an up to 80% lifetime risk of developing breast cancer. It is especially important to understand the experiences of these women, as their lives are permeated with the threat of cancer. This qualitative study examined the experiences of six young women of reproductive age (age < 45 years) who were identified as carriers. The analysis of the semi-structured interviews inspired by grounded theory methodology, showed that participants experienced the same type of uncertainty demonstrated by women who have already been diagnosed with breast cancer.

Dietary management of urea cycle disorders: UK practice

BACKGROUND

There is no published data describing UK dietary management of urea cycle disorders (UCD). The present study describes dietary practices in UK inherited metabolic disorder (IMD) centres.

METHODS

Cross-sectional data from 16 IMD centres were collected by a questionnaire describing the management of UCD patients on prescribed protein-restricted diets.

RESULTS

One hundred and seventy-five patients [N-acetylglutamate synthase deficiency, n = 3; carbamoyl phosphate synthase deficiency (CPS), n = 8; ornithine transcarbamoylase deficiency (OTC), n = 75; citrullinaemia, n = 41; argininosuccinic aciduria (ASA), n = 36; arginase deficiency, n = 12] were reported; 70% (n = 123) aged 0-16 years; 30% (n = 52) >16 years. Prescribed median protein intake decreased with age (0-6 months: 2 g kg(-1) day(-1); 7-12 months: 1.6 g kg(-1) day(-1); 1-10 years: 1.3 g kg(-1) day(-1); 11-16 years: 0.9 g kg(-1) day(-1) and >16 years: 0.8 g kg(-1) day(-1)) with little variation between disorders. Adult protein prescription ranged 0.4-1.2 g kg(-1) day(-1) (40-60 g day(-1)). In the previous 2 years, 30% (n = 53) were given essential amino acid supplements (EAAs) (CPS, n = 2; OTC, n = 20; citrullinaemia, n = 15; ASA, n = 7; arginase deficiency, n = 9). EAAs were prescribed for low plasma quantitative essential amino acids (n = 13 centres); inadequate natural protein intake (n = 11) and poor metabolic control (n = 9). From diagnosis, one centre prescribed EAAs for all patients and one centre for severe defects only. Only 3% (n = 6) were given branch chain amino acid supplements. Enteral feeding tubes were used by 25% (n = 44) for feeds and 3% (n = 6) for medications. Oral energy supplements were prescribed in 17% (n = 30) of cases.

CONCLUSIONS

In the UK, protein restriction based on World Health Organization 'safe intakes of protein', is the principle dietary treatment for UCD. EAA supplements are prescribed mainly on clinical need. Multicentre collaborative research is required to define optimal dietary treatments.

P3-08-04: “How Important Is This for Me?” – The Role of Necessity Beliefs as Determinants of Breast Cancer Prevention Intentions among High-Risk Women

Background Women at elevated risk for breast cancer (BC) face complex risk management decisions. Understanding the determinants of pre-counselling risk management intentions would be useful to clinicians in helping high-risk women make their decisions. Across several medical conditions, the Necessity-Concerns Framework (NCF) has emphasized the role of patient’ beliefs about interventions offered to them as central to decision-making. In the NCF, beliefs are conceptualized as perceived personal need for an intervention (necessity) and as concerns about its perceived negative effects. To date, the NCF has not been applied to investigate decision-making in the high-risk setting. Our objective was to use the NCF to describe the risk management beliefs of high-risk women prior to initial consultation. The relative importance of BC fear, perceived susceptibility to BC and necessity-concerns beliefs in predicting prevention intentions was also examined.

Methods A survey was sent to patients prior to their first risk consultation. BC fear was assessed with Champion BC Fear Scale and perceived susceptibility was measured by asking women to rate their likelihood of developing BC (0 =definitely will not get it to 100=definitely will get it). For each of screening, lifestyle modifications, pharmacoprevention (PP) and prophylactic surgery (PS), women rated (1=strongly disagree to 5=strongly agree) their need for the option (e.g., my health in the future will depend on this option, this option will protect me from becoming worse), and its negative consequences (e.g. I worry about the long-term effects of this option, this option will disrupt my life). Intentions were assessed by asking how strongly (1=definitely not to 5=Definitely Yes) they intended to adopt each option. The planned sample size is 100 women and recruitment is on-going. We report data from 44 women who have completed the questionnaire.

Results: The majority intended to adopt screening (92%) and lifestyle (91%) compared to PP (23%) or PS (18%). Screening and lifestyle were associated with stronger intentions, higher perceived need, and lower concerns than PP and PS (all t-tests, p &lt;0.0001). Hierarchical regression analyses revealed that perceived need predicted intentions for each option (all ps &lt; 0.005, except for screening, p &lt; .1) whereas concern beliefs were only correlated with PP intentions (β=-.398, p &lt; .005). Fear of BC was related to PP intentions (β=.401, p &lt; .005) and to intentions to remain smoke-free (β=-.341, p &lt; .05). Perceived susceptibility did not contribute to intentions.

Conclusions Our preliminary findings are promising and suggest that the NCF is useful for understanding decision-making in the high-risk setting. The findings emphasize the importance of necessity beliefs in BC risk management decisions. For the group as whole, across each risk management option, the strongest predictor of intentions was a women's perception of her personal need for the option. Concerns about negative effects and BC fear played only a minor role and perceived susceptibility did not predict intentions. These observations stress the importance of making screening or prevention recommendations hand in hand with the individual beliefs and concerns.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-08-04.

Complete genome sequence of Meiothermus silvanus type strain (VI-R2)

Meiothermus silvanus (Tenreiro et al. 1995) Nobre et al. 1996 belongs to a thermophilic genus whose members share relatively low degrees of 16S rRNA gene sequence similarity. Meiothermus constitutes an evolutionary lineage separate from members of the genus Thermus, from which they can generally be distinguished by their slightly lower temperature optima. M. silvanus is of special interest as it causes colored biofilms in the paper making industry and may thus be of economic importance as a biofouler. This is the second completed genome sequence of a member of the genus Meiothermus and only the third genome sequence to be published from a member of the family Thermaceae. The 3,721,669 bp long genome with its 3,667 protein-coding and 55 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

Genome erosion in a nitrogen-fixing vertically transmitted endosymbiotic multicellular cyanobacterium

Background

An ancient cyanobacterial incorporation into a eukaryotic organism led to the evolution of plastids (chloroplasts) and subsequently to the origin of the plant kingdom. The underlying mechanism and the identities of the partners in this monophyletic event remain elusive.

Methodology/Principal Findings

To shed light on this evolutionary process, we sequenced the genome of a cyanobacterium residing extracellularly in an endosymbiosis with a plant, the water-fern Azolla filiculoides Lam. This symbiosis was selected as it has characters which make it unique among extant cyanobacterial plant symbioses: the cyanobacterium lacks autonomous growth and is vertically transmitted between plant generations. Our results reveal features of evolutionary significance. The genome is in an eroding state, evidenced by a large proportion of pseudogenes (31.2%) and a high frequency of transposable elements (∼600) scattered throughout the genome. Pseudogenization is found in genes such as the replication initiator dnaA and DNA repair genes, considered essential to free-living cyanobacteria. For some functional categories of genes pseudogenes are more prevalent than functional genes. Loss of function is apparent even within the ‘core’ gene categories of bacteria, such as genes involved in glycolysis and nutrient uptake. In contrast, serving as a critical source of nitrogen for the host, genes related to metabolic processes such as cell differentiation and nitrogen-fixation are well preserved.

Conclusions/Significance

This is the first finding of genome degradation in a plant symbiont and phenotypically complex cyanobacterium and one of only a few extracellular endosymbionts described showing signs of reductive genome evolution. Our findings suggest an ongoing selective streamlining of this cyanobacterial genome which has resulted in an organism devoted to nitrogen fixation and devoid of autonomous growth. The cyanobacterial symbiont of Azolla can thus be considered at the initial phase of a transition from free-living organism to a nitrogen-fixing plant entity, a transition process which may mimic what drove the evolution of chloroplasts from a cyanobacterial ancestor.

International integrated database for the evaluation of severe sepsis and drotrecogin alfa (activated) therapy: analysis of efficacy and safety data in a large surgical cohort

BACKGROUND

The International Integrated Database for the Evaluation of Severe Sepsis and Drotrecogin alfa (activated) Therapy includes an extensive cohort of surgical patients (1659/4459; 37%). This database broadens the experience reported on a comparatively small set of surgical patients from the pivotal Protein C Worldwide Evaluation in Severe Sepsis trial to examine issues of safety and efficacy in a much larger cohort.

METHODS

We conducted a retrospective analysis of prospectively defined outcomes from 5 integrated clinical studies of severe sepsis. Multivariable analyses incorporated propensity scores, treatment, and significant baseline risk factors as independent variables in logistic regression models for 2 outcomes: serious adverse events that were observed during infusion and 28-day, all-cause mortality rates. Adjusted odds ratios were calculated for clinically important strata. Multiple subcategories of serious bleeding-event rates are presented.

RESULTS

Although surgical patients who were treated with drotrecogin alfa [activated] (DrotAA) experienced a greater proportion of serious bleeding events during the infusion period, most of the patients were treated without fatal consequence. A 10.7% absolute all cause mortality risk reduction (adjusted odds ratio, 0.66; 95% CI, 0.45-0.97) was observed for DrotAA-treated, high-risk (Acute Physiology and Chronic Health Evaluation II, >/= 25) surgical patients. We could not demonstrate a survival benefit in DrotAA-treated, low-risk (Acute Physiology and Chronic Health Evaluation II, <25) surgical patients. When surgical patients were stratified by number of organ dysfunctions, absolute risk reductions were observed in both categories: multiorgan (4.3%) and single (4.5%).

CONCLUSION

International Integrated Database for the Evaluation of Severe Sepsis and Drotrecogin alfa (activated) Therapy analyses affirmed the favorable benefit/risk profile of DrotAA for surgical patients. The serious adverse event rate that was experienced by surgical patients during the study drug infusion period was 7.5% in the DrotAA-treated group versus 6.3% in the placebo-treated group (odds ratio, 1.41; 95% CI, 0.89-2.25). The clinical benefit of DrotAA therapy paralleled baseline risk of death and substantiated findings from the Protein C Worldwide Evaluation in Severe Sepsis study. Future analyses are needed to evaluate the special relationships among sepsis severity, bleeding management, and the postoperative timing of DrotAA administration.

International integrated database for the evaluation of severe sepsis and drotrecogin alfa (activated) therapy: analysis of efficacy and safety data in a large surgical cohort

BACKGROUND

The International Integrated Database for the Evaluation of Severe Sepsis and Drotrecogin alfa (activated) Therapy includes an extensive cohort of surgical patients (1659/4459; 37%). This database broadens the experience reported on a comparatively small set of surgical patients from the pivotal Protein C Worldwide Evaluation in Severe Sepsis trial to examine issues of safety and efficacy in a much larger cohort.

METHODS

We conducted a retrospective analysis of prospectively defined outcomes from 5 integrated clinical studies of severe sepsis. Multivariable analyses incorporated propensity scores, treatment, and significant baseline risk factors as independent variables in logistic regression models for 2 outcomes: serious adverse events that were observed during infusion and 28-day, all-cause mortality rates. Adjusted odds ratios were calculated for clinically important strata. Multiple subcategories of serious bleeding-event rates are presented.

RESULTS

Although surgical patients who were treated with drotrecogin alfa [activated] (DrotAA) experienced a greater proportion of serious bleeding events during the infusion period, most of the patients were treated without fatal consequence. A 10.7% absolute all cause mortality risk reduction (adjusted odds ratio, 0.66; 95% CI, 0.45-0.97) was observed for DrotAA-treated, high-risk (Acute Physiology and Chronic Health Evaluation II, >or=25) surgical patients. We could not demonstrate a survival benefit in DrotAA-treated, low-risk (Acute Physiology and Chronic Health Evaluation II, <25) surgical patients. When surgical patients were stratified by number of organ dysfunctions, absolute risk reductions were observed in both categories: multiorgan (4.3%) and single (4.5%).

CONCLUSION

International Integrated Database for the Evaluation of Severe Sepsis and Drotrecogin alfa (activated) Therapy analyses affirmed the favorable benefit/risk profile of DrotAA for surgical patients. The serious adverse event rate that was experienced by surgical patients during the study drug infusion period was 7.5% in the DrotAA-treated group versus 6.3% in the placebo-treated group (odds ratio, 1.41; 95% CI, 0.89-2.25). The clinical benefit of DrotAA therapy paralleled baseline risk of death and substantiated findings from the Protein C Worldwide Evaluation in Severe Sepsis study. Future analyses are needed to evaluate the special relationships among sepsis severity, bleeding management, and the postoperative timing of DrotAA administration.

The need for flexibility in the operative management of type III paraesophageal hernias

BACKGROUND

A myriad of operation exist to treat type III paraesophageal hernias (T3PH). How does one choose?

METHODS

A retrospective review of a consecutive series of resident-preformed T3PH repair.

RESULTS

Three patients with T3PH were operated on during a 6-year period. The presentation of each patient was unique. Three different surgical procedures were used to treat these patients depending on the patient's condition at presentation, the location of the gastroesophageal junction, and the documentation of reflux. Transabdominal hernia reduction and a modified Hill procedure was used in 1 patient; a transthoracic hernia reduction was supplemented with a either a Belsy-Mark IV fundoplication or a Collis-Nissen gastroplasty in the other 2 patients. Patients were discharged home 7 (3-13) days postoperatively, and at a mean follow-up of 23 (2-60) months, all patients are asymptomatic and without radiographic recurrence.

CONCLUSION

Operative selection for T3PH should be flexible depending on the (1) urgency of symptoms, (2) location of the gastroesophageal junction, and (3) evidence for gastroesophageal reflux.

Recombinant human platelet-activating factor acetylhydrolase for treatment of severe sepsis: results of a phase III, multicenter, randomized, double-blind, placebo-controlled, clinical trial

OBJECTIVE

Platelet-activating factor (PAF) and structurally-related oxidized phospholipids are proinflammatory mediators in systemic inflammatory states such as severe sepsis. The enzyme platelet-activating factor acetylhydrolase (PAF-AH) rapidly degrades PAF and oxidized phospholipids into inactive metabolites. Reduced PAF-AH activity has been observed in patients with severe sepsis and may contribute to their systemic inflammatory response and organ dysfunction. A previous clinical trial with recombinant human PAF-AH (rPAF-AH, Pafase) suggested that this treatment may decrease 28-day all-cause mortality in patients with severe sepsis. The current study was undertaken to confirm this result.

DESIGN

A prospective, randomized, double-blind, placebo-controlled, multicenter, international trial.

SETTING

One hundred forty-six intensive care units from nine countries.

PATIENTS

Approximately 2,522 patients were planned to be enrolled < or =12 hrs after the onset of severe sepsis. Eligible patients were randomized to receive either rPAF-AH 1.0 mg/kg or placebo administered intravenously once daily for five consecutive days.

MEASUREMENTS AND MAIN RESULTS

The study was terminated based on the recommendation of an independent data and safety monitoring committee after the second of three planned interim analyses, and the enrollment of 1,425 patients. rPAF-AH treatment was well tolerated among the 1,261 patients included in the interim analysis (643 rPAF-AH and 618 placebo), but did not decrease 28-day all-cause mortality compared with placebo (25% for rPAF-AH vs. 24% for placebo; relative risk, 1.03; 95% confidence interval, 0.85-1.25; p =.80). There were no statistically significant differences between treatment groups in any of the secondary efficacy end points. The overall incidence of adverse events was similar among rPAF-AH and placebo-treated patients, and no rPAF-AH-treated patients developed antibodies to PAF-AH.

CONCLUSIONS

rPAF-AH was well tolerated and not antigenic, but did not decrease 28-day all-cause mortality in patients with severe sepsis.

Recombinant platelet-activating factor acetylhydrolase to prevent acute respiratory distress syndrome and mortality in severe sepsis: Phase IIb, multicenter, randomized, placebo-controlled, clinical trial

OBJECTIVE

Platelet-activating factor (PAF) is a potent proinflammatory mediator implicated in the pathogenesis of both severe sepsis and acute respiratory distress syndrome. One of the regulatory pathways for PAF involves degradation to the inactive metabolite lyso-PAF by the enzyme PAF acetylhydrolase (PAF-AH). Because reduced concentrations of the natural form of PAF-AH have been reported in septic patients, the present study was conducted to determine whether treatment with recombinant human PAF-AH (rPAF-AH, Pafase) was safe when administered after the onset of severe sepsis and whether it decreases the prevalence of acute respiratory distress syndrome and 28-day all-cause mortality.

DESIGN

A prospective, randomized, double-blind, placebo-controlled, multicenter trial.

SETTING

Thirty-three medical and surgical intensive care units located in the United States.

PATIENTS

A total of 127 patients with severe sepsis, but without established acute respiratory distress syndrome, were enrolled in the study. Randomization occurred within 12 hrs of the onset of severe sepsis. Patients then received 1.0 mg/kg rPAF-AH (n = 45), 5.0 mg/kg rPAF-AH (n = 39), or placebo (n = 43) administered intravenously, once daily, for five consecutive days.

MEASUREMENTS AND MAIN RESULTS

Demographic and baseline clinical characteristics of the three treatment groups were similar, except for a significantly higher prevalence of respiratory tract infections as the cause of severe sepsis in patients treated with 1.0 mg/kg rPAF-AH. There were no treatment-related deaths, and the overall prevalence of adverse events was similar among rPAF-AH-treated and placebo-treated patients. There were no significant differences in the prevalence of acute respiratory distress syndrome among the three treatment groups. However, 28-day all-cause mortality was 21% in the 1.0 mg/kg rPAF-AH group, 28% in the 5.0 mg/kg rPAF-AH group, and 44% in the placebo group (overall chi-square p =.07; 1.0 mg/kg rPAF-AH vs. placebo, p =.03). A trend toward reduced multiple organ dysfunction also was observed in the 1.0 mg/kg rPAF-AH group compared with the placebo group (p =.11).

CONCLUSION

The results from this study indicate that rPAF-AH was well tolerated and should be pursued as a potential new treatment to decrease mortality in patients with severe sepsis.

Integration of cytogenetic landmarks into the draft sequence of the human genome

We have placed 7,600 cytogenetically defined landmarks on the draft sequence of the human genome to help with the characterization of genes altered by gross chromosomal aberrations that cause human disease. The landmarks are large-insert clones mapped to chromosome bands by fluorescence in situ hybridization. Each clone contains a sequence tag that is positioned on the genomic sequence. This genome-wide set of sequence-anchored clones allows structural and functional analyses of the genome. This resource represents the first comprehensive integration of cytogenetic, radiation hybrid, linkage and sequence maps of the human genome; provides an independent validation of the sequence map and framework for contig order and orientation; surveys the genome for large-scale duplications, which are likely to require special attention during sequence assembly; and allows a stringent assessment of sequence differences between the dark and light bands of chromosomes. It also provides insight into large-scale chromatin structure and the evolution of chromosomes and gene families and will accelerate our understanding of the molecular bases of human disease and cancer.

Multicenter clinical trial of recombinant human insulin-like growth factor I in patients with acute renal failure

BACKGROUND

Patients with acute renal failure (ARF) have high morbidity and mortality rates, particularly if they have serious comorbid conditions. Several studies indicate that in rats with ARF caused by ischemia or certain nephrotoxins, insulin-like growth factor-I (IGF-I) enhances the recovery of renal function and suppresses protein catabolism.

METHODS

Our objective was to determine whether injections of recombinant human IGF-I (rhIGF-I) would enhance the recovery of renal function and is safe in patients with ARF. The study was designed as a randomized, double-blind, placebo-controlled trial in intensive care units in 20 teaching hospitals. Seventy-two patients with ARF were randomized to receive rhIGF-I (35 patients) or placebo (37 patients). The most common causes of ARF in the rhIGF-I and placebo groups were, respectively, sepsis (37 and 35% of patients) and hypotension or hemodynamic shock (42 and 27% of patients). At baseline, the mean (+/- SD) APACHE II scores in the rhIGF-I and placebo-treated groups were 24 +/- 5 and 25 +/- 8, respectively. In the rhIGF-I and placebo groups, the mean (median) urine volume and urinary iothalamate clearances (glomerular filtration rate) were 1116 +/- 1037 (887) and 1402 +/- 1183 (1430) ml/24 hr and 6.4 +/- 5.9 (4.3) and 8.7 +/- 7.2 (4.4) ml/min and did not differ between the two groups. Patients were injected subcutaneously every 12 hours with rhIGF-I, 100 microgram/kg desirable body weight, or placebo for up to 14 days. Injections were started within six days of the onset of ARF. The primary end-point was a change in glomerular filtration rate from baseline. Other end points included changes from baseline in urine volume, creatinine clearance and serum urea, creatinine, albumin and transferrin, frequency of hemodialysis or ultrafiltration, and mortality rate.

RESULTS

During the treatment period, which averaged 10.7 +/- 4.1 and 10.6 +/- 4.5 days in the rhIGF-I and placebo groups, there were no differences in the changes from baseline values of the glomerular filtration rate, creatinine clearance, daily urine volume, or serum urea nitrogen, creatinine, albumin or transferrin. In patients who did not receive renal replacement therapy, there was also no significant difference in serum creatinine and urea between the two groups. Twenty patients in the rhIGF-I group and 17 placebo-treated patients underwent dialysis or ultrafiltration. Twelve rhIGF-I-treated patients and 12 placebo-treated patients died during the 28 days after the onset of treatment.

CONCLUSIONS

rhIGF-I does not accelerate the recovery of renal function in ARF patients with substantial comorbidity.

Evaluation of undergraduate medical education - why and how?

The education of physicians both at the undergraduate and graduate level is no longer a matter for an individual professor or department in a medical faculty. The curriculum has to be developed and carried out according to the needs of the society in which the physician is going to function. Evaluation of the educational programme by external reviewers should therefore be seen as a normal part of the quality control process of all medical faculties. The most important part of such an evaluation is the self-assessment performed by the faculty and the students; self-assessment, together with advice from the external reviewers, will constitute the basis for necessary curriculum changes.

Fatal fentanyl intoxication following excessive transdermal application

The case history and toxicological findings of a fatal fentanyl intoxication due to the application of multiple transdermal patches are presented. An 83 year-old white female with terminal cancer was found dead with three 100 mg/h fentanyl patches on her chest. The autopsy and subsequent histological studies revealed extensive areas of gastric carcinoma, a large atrial tumor, ulceration of esophagus, metastasis of peripancreatic lymph nodes and a recent surgical removal of part of the lower lobe of the left lung. Toxicological analysis by GC/MS yielded fentanyl concentrations of blood, 25 ng/mL; brain, 54 ng/g; heart 94 ng/g; kidney 69 ng/g; and liver 104 ng/g. The cause of death was determined to be fentanyl overdose and the manner of death was ruled undetermined as the investigation was unable to conclusively establish whether this was an accidental overdose, a suicide, an assisted suicide, or possible a homicide. This case demonstrates the need for caution in self-administration of transdermal fentanyl patches, in particular, the dangers inherent in the application of multiple patches which can result in the release of potentially toxic or lethal doses.

Fatal ephedrine intoxication

A 28-year-old white female with a history of two prior suicide attempts was found dead in her home by her common law husband. Autopsy findings were unremarkable except for partially dissolved ephedrine tablets in the stomach contents. Quantitation of ephedrine was by gas chromatography/mass spectrometry (GC/MS) following liquid/liquid extraction from alkaline samples and pentafluoropropionic acid derivatization. Significant toxicological finding included ephedrine; blood, 11 mg/L; liver, 24 mg/kg; kidney, 14 mg/kg; brain, 8.9 mg/kg; and amitriptyline; blood, 0.33 mg/kg; liver 7.8 mg/kg. The ephedrine values found far exceed those associated with therapeutic administration and are consistent with the few reported cases of severe ephedrine intoxication. The cause of death was determined to be fatal ephedrine intoxication and manner of death suicide.

Association of periodontal disease and histologic lesions in multiple organs from 45 dogs

Forty-five mixed breed dogs were evaluated for the presence and extent of periodontal disease. Histopathology was performed on samples of lung, myocardium, liver, kidney, tonsil, spleen, submandibular lymph node and tracheobronchial lymph node. Mitral valves were evaluated grossly. Statistical analysis was used to determine if there was a relationship between the extent of periodontal disease and histopathologic changes in the tissues examined. In the forty-five dogs studied, an association was found between periodontal disease and histopathologic changes in kidney, myocardium (papillary muscle), and liver.

Reduction in accumulation of plaque, stain, and calculus in dogs by dietary means

We conducted 215 evaluations for plaque, stain, and calculus in 120 dogs at two research sites. Dogs were balanced in groups of five according to baseline plaque index scores; groups were randomly assigned to treatment or control dietary regimens. Dental cleanings were done on Day 0. Dogs in the treatment group were fed a food formulated to reduce accumulation of plaque, stain, and calculus. Control group dogs were fed a commercially available dry dog food. No other foods, treats, or snacks were given to either group. We graded 22 teeth for plaque accumulation on Day 7 and for stain and calculus accumulation on Day 21. Six trials were conducted and the results reported as a combined mean for all treatment and control groups. Dogs fed the treatment food had significantly less plaque, stain, and calculus accumulation (p = 0.001) than dogs fed the control food. Plaque, stain, and calculus accumulation can be reduced by dietary means.

Postgraduate training for overseas doctors in Britain

Foreign doctors, other than those from the European Economic Area, who want to train in Britain have to satisfy registration and immigration requirements before they can take up a post. The General Medical Council administers the registration regulations. These are quite separate from the immigration formalities, which are handled by the Home Office. The rules on both are complicated, and doctors should seek advice early to ensure that unnecessary difficulties do not add to the inevitable stresses associated with moving to a new country and working in a strange system.

Making change happen

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Trends in health care and their effects on medical education

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