185 research outputs found
Routine immunofluorescent and histochemical analysis of bone marrow involvement of lymphoma/leukaemia: the use of cryostat sections.
Enzyme histochemical and immunohistological (immuno-fluorescence and -peroxidase) techniques have been routinely used for investigating over 70 normal and pathological bone marrow samples. This recently standardized diagnostic procedure is very quick and can be performed in a few hours. In 6 cases the clinical diagnosis of leukaemia/lymphoma has become apparent only after the immunohistological analysis of the bone marrow. In 6 other cases the information about the staging of B cell malignancies was superior in the frozen biopsies to the paraffin embedded preparations. Amongst many other features the monoclonality of B CLL/lymphomas, the special features of B CLL infiltrates (RFA-1+, Leu-1+, HLA-DR+, SmIg+), follicular lymphoma deposits (containing follicular dendritic cells) and non-T, non-B acute lymphoblastic leukaemic blasts (terminal transferase+, HLA-DR+) as well as the sometimes conspicuous presence of infiltrating normal T cells could be clearly and reproducibly demonstrated
Quiescent and flare analysis for the chromospherically active star Gl355 (LQHya)
We discuss ROSAT and ASCA observations of the young active star Gl355}.
During the ROSAT observation a strong flare was detected with a peak flux more
than an order of magnitude larger than the quiescent level. Spectral analysis
of the data allows us to study the temperature and emission measure
distribution, and the coronal metal abundance, for the quiescent phase and, in
the case of ROSAT, also during the evolution of the flare. The global coronal
metallicity derived from both ROSAT and ASCA data is
much lower than solar and presumably also much lower than the photospheric
abundance expected for this very young star. The temperature structure of the
quiescent corona was about the same during the various observations, with a
cooler component at MK and a hotter component (to which only ASCA
was sensitive) at MK. During the flare, the low temperature
component remained approximately constant and equal to the quiescent value,
while the high-temperature component was the only one that varied. We have
modeled the flare with the hydrodynamic-decay sustained-heating approach of
Reale at al. (1997) and we have derived a loop semi--length of the order of
stellar radii, i.e. much larger than the dimensions of flares on the
Sun, but comparable with the typical dimensions inferred for other stellar
flares. We have compared the derived loop size with that estimated with a
simpler (but physically inconsistent) approach, finding that for this, as well
for several other stellar flares, the two methods give comparable loop sizes.
Possible causes and consequences of this result are discussed.Comment: A&A, in pres
Assessing Susceptibility from Early-Life Exposure to Carcinogens
Cancer risk assessment methods currently assume that children and adults are equally susceptible to exposure to chemicals. We reviewed available scientific literature to determine whether this was scientifically supported. We identified more than 50 chemicals causing cancer after perinatal exposure. Human data are extremely limited, with radiation exposures showing increased early susceptibility at some tumor sites. Twenty-seven rodent studies for 18 chemicals had sufficient data after postnatal and adult exposures to quantitatively estimate potential increased susceptibility from early-life exposure, calculated as the ratio of juvenile to adult cancer potencies for three study types: acute dosing, repeated dosing, and lifetime dosing. Twelve of the chemicals act through a mutagenic mode of action. For these, the geometric mean ratio was 11 for lifetime exposures and 8.7 for repeat exposures, with a ratio of 10 for these studies combined. The geometric mean ratio for acute studies is 1.5, which was influenced by tissue-specific results [geometric mean ratios for kidney, leukemia, liver, lymph, mammary, nerve, reticular tissue, thymic lymphoma, and uterus/vagina > 1 (range, 1.6–8.1); forestomach, harderian gland, ovaries, and thyroid < 1 (range, 0.033–0.45)]. Chemicals causing cancer through other modes of action indicate some increased susceptibility from postnatal exposure (geometric mean ratio is 3.4 for lifetime exposure, 2.2 for repeat exposure). Early exposures to compounds with endocrine activity sometimes produce different tumors after exposures at different ages. These analyses suggest increased susceptibility to cancer from early-life exposure, particularly for chemicals acting through a mutagenic mode of action
Suppression of circulating IgD+CD27+ memory B cells in infants living in a malaria-endemic region of Kenya
Background: Plasmodium falciparum infection leads to alterations in B cell subset distribution. During infancy,
development of peripheral B cell subsets is also occurring. However, it is unknown if infants living a malaria
endemic region have alterations in B cell subsets that is independent of an age effect.
Methods: To evaluate the impact of exposure to P. falciparum on B cell development in infants, flow cytometry
was used to analyse the distribution and phenotypic characteristic of B cell subsets in infant cohorts prospectively
followed at 12, 18 and 24 months from two geographically proximate regions in western Kenya with divergent
malaria exposure i.e. Kisumu (malaria-endemic, n = 24) and Nandi (unstable malaria transmission, n = 21).
Results: There was significantly higher frequency and absolute cell numbers of CD19+ B cells in Kisumu relative to
Nandi at 12(p = 0.0440), 18(p = 0.0210) and 24 months (p = 0.0493). No differences were observed between the
infants from the two sites in frequencies of naïve B cells (IgD+CD27-) or classical memory B cells (IgD-CD27+).
However, immature transitional B cells (CD19+CD10+CD34-) were higher in Kisumu relative to Nandi at all three
ages. In contrast, the levels of non-class switched memory B cells (CD19+IgD+CD27+) were significantly lower
overall in Kisumu relative to Nandi at significantly at 12 (p = 0.0144), 18 (p = 0.0013) and 24 months (p = 0.0129).
Conclusions: These data suggest that infants living in malaria endemic regions have altered B cell subset
distribution. Further studies are needed to understand the functional significance of these changes and long-term
impact on ability of these infants to develop antibody responses to P. falciparum and heterologous infections
Measurements of branching fraction ratios and CP-asymmetries in suppressed B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^- decays
We report the first reconstruction in hadron collisions of the suppressed
decays B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^-, sensitive to the
CKM phase gamma, using data from 7 fb^-1 of integrated luminosity collected by
the CDF II detector at the Tevatron collider. We reconstruct a signal for the
B^- -> D(-> K^+ pi^-)K^- suppressed mode with a significance of 3.2 standard
deviations, and measure the ratios of the suppressed to favored branching
fractions R(K) = [22.0 \pm 8.6(stat)\pm 2.6(syst)]\times 10^-3, R^+(K) =
[42.6\pm 13.7(stat)\pm 2.8(syst)]\times 10^-3, R^-(K)= [3.8\pm 10.3(stat)\pm
2.7(syst]\times 10^-3, as well as the direct CP-violating asymmetry A(K) =
-0.82\pm 0.44(stat)\pm 0.09(syst) of this mode. Corresponding quantities for
B^- -> D(-> K^+ pi^-)pi^- decay are also reported.Comment: 8 pages, 1 figure, accepted by Phys.Rev.D Rapid Communications for
Publicatio
The sacral chordoma margin
[Objective]: Aim of the manuscript is to discuss how to improve margins in sacral chordoma.
[Background]: Chordoma is a rare neoplasm, arising in half cases from the sacrum, with reported local failure in >50% after surgery.
[Methods]: A multidisciplinary meeting of the “Chordoma Global Consensus Group” was held in Milan in 2017, focusing on challenges in defining and achieving optimal margins in chordoma with respect to surgery, definitive particle radiation therapy (RT) and medical therapies. This review aims to report on the outcome of the consensus meeting and to provide a summary of the most recent evidence in this field. Possible new ways forward, including on-going international clinical studies, are discussed.
[Results]: En-bloc tumor-sacrum resection is the cornerstone of treatment of primary sacral chordoma, aiming to achieve negative microscopic margins. Radical definitive particle therapy seems to offer a similar outcome compared to surgery, although confirmation in comparative trials is lacking; besides there is still a certain degree of technical variability across institutions, corresponding to different fields of treatment and different tumor coverage. To address some of these questions, a prospective, randomized international study comparing surgery versus definitive high-dose RT is ongoing. Available data do not support the routine use of any medical therapy as (neo)adjuvant/cytoreductive treatment.
[Conclusion]: Given the significant influence of margins status on local control in patients with primary localized sacral chordoma, the clear definition of adequate margins and a standard local approach across institutions for both surgery and particle RT is vital for improving the management of these patients
ECMO for COVID-19 patients in Europe and Israel
Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO
support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed
on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients
Search for B_s --> mu+mu- and B_d --> mu+mu- Decays with CDF II
A search has been performed for B_s --> mu+mu- and B_d --> mu+mu- decays
using 7/fb of integrated luminosity collected by the CDF II detector at the
Fermilab Tevatron collider. The observed number of B_d candidates is consistent
with background-only expectations and yields an upper limit on the branching
fraction of BF(B_d-->mu+mu-) < 6.0E-9 at 95% confidence level. We observe an
excess of B_s candidates. The probability that the background processes alone
could produce such an excess or larger is 0.27%. The probability that the
combination of background and the expected standard model rate of B_s -->
mu+mu- could produce such an excess or larger is 1.9%. These data are used to
determine BF(B_s-->mu+mu-) = (1.8^{+1.1}_{-0.9})E-8 and provide an upper limit
of BF(B_s -->mu+mu-) < 4.0E-8 at 95% confidence level.Comment: 7 pages, 1 figure; version accepted by PR
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