A 500-kiloton airburst over Chelyabinsk and an enhanced hazard from small impactors.

Most large (over a kilometre in diameter) near-Earth asteroids are now known, but recognition that airbursts (or fireballs resulting from nuclear-weapon-sized detonations of meteoroids in the atmosphere) have the potential to do greater damage than previously thought has shifted an increasing portion of the residual impact risk (the risk of impact from an unknown object) to smaller objects. Above the threshold size of impactor at which the atmosphere absorbs sufficient energy to prevent a ground impact, most of the damage is thought to be caused by the airburst shock wave, but owing to lack of observations this is uncertain. Here we report an analysis of the damage from the airburst of an asteroid about 19 metres (17 to 20 metres) in diameter southeast of Chelyabinsk, Russia, on 15 February 2013, estimated to have an energy equivalent of approximately 500 (±100) kilotons of trinitrotoluene (TNT, where 1 kiloton of TNT = 4.185×10(12) joules). We show that a widely referenced technique of estimating airburst damage does not reproduce the observations, and that the mathematical relations based on the effects of nuclear weapons--almost always used with this technique--overestimate blast damage. This suggests that earlier damage estimates near the threshold impactor size are too high. We performed a global survey of airbursts of a kiloton or more (including Chelyabinsk), and find that the number of impactors with diameters of tens of metres may be an order of magnitude higher than estimates based on other techniques. This suggests a non-equilibrium (if the population were in a long-term collisional steady state the size-frequency distribution would either follow a single power law or there must be a size-dependent bias in other surveys) in the near-Earth asteroid population for objects 10 to 50 metres in diameter, and shifts more of the residual impact risk to these sizes.

The impact and recovery of asteroid 2008 TC(3).

In the absence of a firm link between individual meteorites and their asteroidal parent bodies, asteroids are typically characterized only by their light reflection properties, and grouped accordingly into classes. On 6 October 2008, a small asteroid was discovered with a flat reflectance spectrum in the 554-995 nm wavelength range, and designated 2008 TC(3) (refs 4-6). It subsequently hit the Earth. Because it exploded at 37 km altitude, no macroscopic fragments were expected to survive. Here we report that a dedicated search along the approach trajectory recovered 47 meteorites, fragments of a single body named Almahata Sitta, with a total mass of 3.95 kg. Analysis of one of these meteorites shows it to be an achondrite, a polymict ureilite, anomalous in its class: ultra-fine-grained and porous, with large carbonaceous grains. The combined asteroid and meteorite reflectance spectra identify the asteroid as F class, now firmly linked to dark carbon-rich anomalous ureilites, a material so fragile it was not previously represented in meteorite collections.

Pneumonectomy in isoflurane-anesthetized rats without tracheal intubation: an experimental model.

INTRODUCTION: A few models for pneumonectomy in rats have been described, and in most of these, anesthesia includes orotracheal intubation, which increases morbidity and mortality and also adds technical complexity. Models without tracheal intubation but with injectable anesthesia are difficult to reproduce, however, and lead to a lengthy postoperative-recovery period with high morbidity and mortality rates. OBJECTIVE: The objective of this study was to describe a simple, safe, and effective experimental model for pneumonectomy in rats without tracheal intubation. MATERIALS AND METHODS: A left-sided pneumonectomy was performed on 26 Sprague-Dawley rats anesthetized by isoflurane applied via a mask without tracheal intubation. To avoid dangerous traction movements, the lung pedicle was ligated en bloc using clips. RESULTS AND DISCUSSION: No rat demonstrated cardiorespiratory depression. Of the 26 rats, 1 was dehydrated and had lost more than 10% of its body weight, resulting in death on the third day after surgery. Total mortality was therefore 3.8%. Mean (standard deviation [SD]) anesthesia duration was 9.8 (1.0) minutes, surgery time was 3.0 (0.6) minutes, and open pneumothorax time was 1.2 (0.3) minutes. Mean (SD) weight loss during the early postoperative period was 4.5% (3.5%). These results were more satisfactory than results obtained using ketamine mixtures as anesthetic agents (ketamine plus xylacine, and ketamine plus diazepam). CONCLUSION: Our model for left-sided pneumonectomy in isoflurane-anesthetized rats does not require endotracheal intubation and is effective, safe, quick, and easily reproducible.

The fall, recovery, orbit, and composition of the Tagish Lake meteorite: a new type of carbonaceous chondrite.

The preatmospheric mass of the Tagish Lake meteoroid was about 200,000 kilograms. Its calculated orbit indicates affinity to the Apollo asteroids with a semimajor axis in the middle of the asteroid belt, consistent with a linkage to low-albedo C, D, and P type asteroids. The mineralogy, oxygen isotope, and bulk chemical composition of recovered samples of the Tagish Lake meteorite are intermediate between CM and CI meteorites. These data suggest that the Tagish Lake meteorite may be one of the most primitive solar system materials yet studied.

Autologous hematopoietic stem cell transplantation has better outcomes than conventional therapies in patients with rapidly progressive systemic sclerosis.

We retrospectively evaluated the efficacy of autologous hematopoietic stem cell transplantation (AHSCT) in 18 patients with rapidly progressive diffuse cutaneous systemic sclerosis (rp-dcSSc), and compared their disease outcomes with those of 36 demographically- and clinically-matched patients treated with conventional therapies. Cutaneous involvement, by performing modified Rodnan skin score (mRss), lung diffusion capacity, by measuring diffusing capacity of lung for carbon monoxide (DLCO), and disease activity, by applying the European Scleroderma Study Group (ESSG) scoring system, were the outcome variables measured at the baseline time and then every 12 months for the following 60 months in both the AHSCT-treated patients and the control group. In the AHSCT group, treatment-related mortality was 5.6%. In this group, both mRss and ESSG scores showed a significant reduction 1 year after AHSCT (P<0.002); and these results were maintained until the end of follow-up. Conversely, DLCO values remained stable during the whole period of follow-up. Survival rate of AHSCT group was much higher than that observed in the whole control group (P=0.0005). The probability that the ESSG score and mRss would remain at a high level, and DLCO could decrease, was significantly higher in the control group as a whole and in the subgroup of control patients treated with cyclophosphamide than in the AHSCT group. This study confirms that the AHSCT is effective in prolonging survival, as well as in inducing a rapid reduction of skin involvement and disease activity, and preserving lung function in patients with rp-dcSSc.

Evaluation of a modified cleaning procedure in the prevention of carbapenem-resistant Acinetobacter baumannii clonal spread in a burn intensive care unit using a high-sensitivity luminometer.

BACKGROUND: Enhanced environmental cleaning practices are among the most accepted measures for controlling the spread of carbapenem-resistant Acinetobacter baumannii (CR-Ab). AIM: To evaluate the impact of heightened cleaning on an ongoing CR-Ab outbreak in a burn intensive care unit (BICU) of an Italian teaching hospital, where chlorhexidine-60% isopropyl alcohol was applied as a complementary disinfectant on high-touch surfaces. METHODS: Compliance with the microbial limit proposed for the BICU by AFNOR-NF-S90-351 (20 colony-forming units/100cm2) was assessed by plate count, and compared with the results obtained with intracellular adenosine triphosphate (ATP) detection. Genotyping was performed using pulsed-field gel electrophoresis. FINDINGS: During the standard cleaning regimen, three out of 23 samples (13%) gave results over the AFNOR limit and five (21.7%) showed unacceptable ATP levels with 100 relative light units/100cm2 as the benchmark limit (sensibility 86.4%, specificity 92.2%). Following improvement of the cleaning procedure, only two samples out of 50 (4%) did not satisfy the microbiological criteria and seven (14%) exceeded the ATP limit. In a successive phase, eight of 30 samples collected showed unacceptable results (27%). CONCLUSIONS: Adding chlorhexidine-60% isopropyl alcohol as complementary disinfectant proved to be effective for reducing environmental microbial contamination, ATP levels and CR-Ab infection/colonization in patients admitted to the BICU. Real-time monitoring by ATP assay was useful for managing the cleaning schedule and reducing hospital infections, although the calculated values must be interpreted as cleanliness indicators rather than risk indicators.

Management of cardiac device infections: A retrospective survey of a non-surgical approach combining antibiotic therapy with transvenous removal.

Pacemakers (PMs) and implantable cardioverter defibrillators (ICDs) have become life-saving therapeutic tools for patients with cardiac arrhythmia. Complications include thrombosis, embolism and infections at a highly variable rate. Surgical removal of the infected device has been perceived as the only way to guarantee a successful outcome and to reduce the high risk of mortality. Recently, a transvenous extraction method has been developed to remove infected intracardiac leads without sternotomy. This survey was designed to evaluate the outcome of an approach combining antibiotic therapy with non-surgical transvenous complete removal for the management of cardiac device infections (CDIs). We reviewed case-histories of 121 patients (105 with PM and 16 with ICD infections). The aim of our retrospective survey was to ascertain that a non-invasive transvenous complete removal of the infected devices is safe and effective when associated with appropriate antibiotic therapy starting 10 days before the procedure and extending to at least three weeks after. The infected devices were successfully removed in all patients with a non-surgical transvenous technique. The infections were most frequently caused by coagulase-negative staphylococci (70%), Staphylococcus aureus (14%), and Gram-negative rods (12%). Polymicrobial infections were documented in 19 patients and represent 16% of all device-related infections. The removal of the devices was done during antibiotic therapy, administered for a median of 26 days (range 23 to 45 days). Neither fatalities nor relapse of infections were recorded in the patient population during the one-year follow-up visits. According to our experience, CDIs can be treated with antibiotic therapy and non-surgical removal of the entire infected device, thus allowing a successful reimplantation. This procedure prevents recurrent infections and operative mortality.

Cytogenetic and myelodysplastic alterations after autologous hemopoietic stem cell transplantation.

Secondary myelodysplastic syndrome/acute myelogenous leukemia (MDS/AML) are today considered a primary complication of autologous hematopoietic stem cell transplantation. In our Center, 83 autografted patients underwent bone marrow (BM) biopsy and cytogenetic analysis at fixed intervals. Twelve patients developed non-clonal cytogenetic abnormalities and 10 patients clonal abnormalities, five of whom (three - 7, one - 5 and one t(9;11)) developed secondary MDS/AML. MDS was also diagnosed in two patients with a normal karyotype. In brief, seven patients (three males, four females; median age 36 years) developed MDS/AML 12-48 months (median 14) after autografting. The FAB diagnosis was AML-M2 in one, chronic myelomonocytic leukemia in two and refractory anemia with excess of blasts in transformation in four cases. Two patients presented a BM biopsy picture of MDS with fibrosis; none of them experienced leukemic transformation. Four MDS patients died, three of leukemic transformation and one of BM insufficiency; the two remaining patients are still living and untransformed. Our data underline the leukemogenic role of previous treatments, even if it is not possible to exclude that underlying disease and/or conditioning therapy may be involved.

Haematopoietic abnormalities after autologous stem cell transplantation in lymphoma patients.

Haematopoietic reconstitution after autologous stem cell transplantation (ASCT) was evaluated at different times in 26 lymphoma patients. All of the patients showed a significant decrease in the number of both committed (CFU-C) and more primitive progenitor cells (LTC-IC). The expansion of bone marrow progenitor cells in a 'stroma-free' long-term liquid culture system supplemented with SCF, IL-3, IL-6 and GM-CSF from 19 transplanted patients was significantly reduced compared to normal controls. The stromal cell compartment, evaluated by means of a CFU-F assay, was also greatly reduced. The number of haematopoietic and stromal cell progenitors was, nevertheless, very similar to their pre-transplant values. Bone marrow histology, which was evaluated at different times after transplant, showed an increase in reticulin fibres, the dilatation of parenchymal sinusoids and some morphological evidence of trilineage dysplasia in 11 patients; however, the same abnormalities were seen in the majority of pre-transplant samples. No cytogenetic abnormalities were observed in 15 patients before transplant, but four subsequently developed persistent clonal karyotypic alterations and five showed non-clonal abnormalities that generally disappeared over time. Our data suggest that both the stromal and the haematopoietic compartments are somehow damaged after ASCT for lymphoma; however, these defects generally pre-exist the transplant conditioning regimen and seem to become less pronounced over time.

Unrelated mismatched cord blood transplantation in an adult with secondary AML.

Umbilical cord blood (CB) has been widely used for related and unrelated transplants in pediatric patients. We present the case of an adult with secondary AML who received an unrelated, one-antigen mismatched CB transplant due to the lack of a matched donor. The patient was a 26-year-old female (35 kg/bw) who had received an autologous bone marrow transplant for Hodgkin's disease in April 1994 and, 6 months later, developed secondary MDS (RAEB, 46, XX, -7, +mar), which slowly evolved into acute myelogenous leukemia. In May 1995, she was transplanted with a 165 ml CB unit containing a total of 1.6 x 10(9) nucleated cells, 11 x 10(6) CD34+ cells and 7.2 x 10(5) CFU-GM. GVHD prophylaxis consisted of standard CsA and methotrexate. Myeloid engraftment occurred on day +28 (PMN > 500) and full donor chimerism was confirmed twice (on days +33 and +56) by means of cytogenetics and DNA microsatellite analysis. Erythroid and megakaryocytic engraftment was documented by immunohistochemical analysis of a bone marrow biopsy on day +40, showing the presence of erythroblastic islands and isolated CD61+ immature cells. The patient did not develop GVHD but died on day +56 from idiopathic interstitial pneumonia and multiorgan failure. To our knowledge, this is one of the first case reports of unrelated mismatched CB transplantation in an adult.

Autologous bone marrow transplantation in advanced Hodgkin's disease.

Autologous bone marrow transplantation (ABMT) has been proposed as an alternative treatment of resistant/refractory Hodgkin's disease (HD). Thirty-seven patients in various phases of HD underwent autografting in our Center: fourteen received a CBV conditioning regimen, the others BCNU or VP16 followed by cyclophosphamide and TBI. Three patients died before engraftment, 28 (75.67%) achieved CR and 6 showed persistent disease. As of March 1996, 18 patients had died and 13 were in continuous CR. The median event-free survival (EFS) and 3-year EFS chances were respectively 9 months and 31.3% in the series as a whole, 14 months and 40% in primary resistant disease, 9 months and 28.4% in responsive relapse, and 3 months and 22.2% in resistant relapse. As many of these patients had failed to respond to third-line therapies, their EFS figures are primarily attributable to the therapeutic efficacy of ABMT. Furthermore, since the EFS curves are better in patients seemingly characterized by a lower chance of chemoresistance, our data favour the use of ABMT in the earlier phases of HD.

G-CSF after autologous hemopoietic stem cell transplantation in malignant lymphoma.

Forty-eight autografted patients were studied after treatment with granulocyte-colony stimulating factor (G-CSF) and were compared with a historical series of 24 patients autografted with bone marrow (BM) without G-CSF. When the patients were divided on the basis of G-CSF administration, type of lymphoma and the source of hemopoietic stem cells, no significant difference was found in the median number of infused BM cells, duration of febrile episodes, platelet and hemoglobin recovery, or in the number of transfusions. The patients receiving peripheral blood (PB) + G-CSF had significantly shorter median durations of antibiotic therapy, hospital stay and polymorphonucleate (PMN) recovery. When the Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL) cases were considered separately, a significant difference between those receiving and those not receiving G-CSF was observed only in the HD group. The advantage offered by PB + G-CSF over BM + G-CSF was far more evident in the NHL group than in HD. It can be concluded that G-CSF improves the outcome of BM transplant in HD, and that the use of PB + G-CSF adds a further advantage; conversely, in NHL, PB + G-CSF is strikingly superior to BM + G-CSF, but the addition of G-CSF adds little advantage.

Ion chromatographic determination of inositol in infant formulae and clinical products for enteral feeding.

An ion chromatographic method is described for the determination of inositol in infant formula and products for enteral feeding. A two-step procedure for hydrolysis and extraction of total inositol has been developed, involving alkaline hydrolysis with 3 M potassium hydroxide and enzymatic dephosphorylation. Substances having a long chromatographic retention time were removed with an ion-exchange resin. Inositol was separated on a high-resolution ion-exchange column and detected by pulsed amperometric detection. Phytic acid interferes only slightly in the analysis. This method can be used for determination of total inositol in infant formulae, and enteral feeding products. The analytical method gave an average recovery of 94% from infant formula samples spiked with inositol and a recovery of 86+/-3% from products spiked with lecithin.

Moderate zinc and vitamin A deficiency in breast milk of mothers from East-Jakarta.

OBJECTIVE: To gain information about the micronutrient status of urban, middle-income, breast-feeding mothers in relation to zinc and selected fat-soluble vitamins in plasma and breast milk and to assess possible interaction between the measured micronutrients. DESIGN: Cross-sectional study. SUBJECTS: 91 mothers and their infants living in middle-income areas of Jakarta, Indonesia. RESULTS: None of the measured anthropometric data of the mothers (e.g. BMI: 22.0+/-3.1 kg/m2) and their infants (birth weight: 3.2+/-0.5 kg) gave any indication of undernutrition. The mean concentrations in blood were 124+/-18 g/l for hemoglobin, 385+/-111 microg/l for retinol, 34+/-23 microg/l for alpha-carotene, 104+/-72 microg/l for beta-carotene, 7.7+/-3.3 mg/l for alpha-tocopherol, 0.57+/-0.23 mg/l for gamma-tocopherol, 855+/-242 microg/l for zinc, and the median concentration of lycopene was 29 microg/l. The median breast milk concentrations were 420 microg/l for retinol, 7.8 microg/l for beta-carotene, and 2.7 mg/l for zinc. With increased duration of lactation, vitamin A and zinc concentrations significantly decreased in breast milk whereas plasma zinc concentration increased. Plasma alpha- and beta-carotene were positively correlated (P < 0.0001) with each other and with plasma lycopene. Breast milk beta-carotene was positively correlated with breast milk retinol and with plasma beta-carotene (P < 0.0001). There was no correlation between zinc and vitamin A in either breast milk or plasma. Forty per cent of the mothers were anemic, 29.1% had a low plasma zinc concentration, and 23.7% had a moderately low plasma vitamin A concentration. Breast milk from 70% of the women had a low concentration of vitamin A and that from 66% had a low concentration of zinc. CONCLUSIONS: Multi-micronutrient intervention should be considered to provide a sufficient supply of zinc and vitamin A for growth of exclusively breast-fed infants.

Microbiological activity and clinical efficacy of a colistin and rifampin combination in multidrug-resistant Pseudomonas aeruginosa infections.

The aim of the study was to assess the microbiological activity and clinical efficacy of colistin and rifampin combination against multidrug-resistant (MDR) Pseudomonas aeruginosa infections. The antimicrobial activity of the colistin/rifampin combination was evaluated using the checkerboard and time-kill curve methods against different MDR P. aeruginosa strains. The combination of rifampin and colistin resulted fully (1 strain) or partially (5 strains) synergistic for 6/7 strains and minimum inhibitory concentrations (MICs) in combination were reduced to easily obtainable therapeutic levels. The time-kill curves showed that the combination was bactericidal against the strains tested. The clinical efficacy of the combination was tested in four patients with difficult-to treat infections (sepsis or pneumonia) caused by MDR P. aeruginosa. All infections were successfully treated. Our microbiological and clinical observations suggest that the addition of rifampin to colistin may result in a synergistic bactericidal combination that may be useful in patients with infections caused by MDR P. aeruginosa which are difficult to cure.

IgD Multiple Myeloma Paraproteinemia as a Cause of Myositis.

A 48-years old man was diagnosed an IgD-k multiple myeloma (MM) at age 38 years for which he successfully underwent chemotherapy and bone marrow transplant. He then developed a graft-versus-host disease (GVHD) whose manifestations included, three years later, a polymyositis, diagnosed at muscle biopsy and successfully treated with steroids. Few months after polymyositis remission, myeloma relapsed and the patient was treated with thalidomide for six years with good remission. Soon after thalidomide suspension, MM relapsed again and the patient came to our observation for a new onset of neuromuscular symptoms. He underwent both muscle and peripheral nerve biopsy to discriminate between myositis (paraproteinemia versus GVHD), amyloidosis, and thalidomide toxicity. The first muscle biopsy showed an inflammatory pattern with necrotic fibres, macrophagical invasion (CD68 positive), rare interstitial cellular infiltrates (CD8 positive and CD4 negative), widespread anti-HLA positivity and negative antiMAC. The second muscle biopsy showed the same inflammatory pattern plus an involvement of blood vessels. Direct immunofluorescence for IgD showed diffuse positivity along the sarcolemmal in both muscle biopsies. Sural nerve biopsy demonstrated both demyelinating and axonal aspects with no inflammatory infiltrates, but positivity for HLA and MAC. Congo Red was negative in both skeletal muscle and peripheral nerve.