Tritium Beta Spectrum Measurement and Neutrino Mass Limit from Cyclotron Radiation Emission Spectroscopy.

The absolute scale of the neutrino mass plays a critical role in physics at every scale, from the subatomic to the cosmological. Measurements of the tritium end-point spectrum have provided the most precise direct limit on the neutrino mass scale. In this Letter, we present advances by Project 8 to the cyclotron radiation emission spectroscopy (CRES) technique culminating in the first frequency-based neutrino mass limit. With only a cm^{3}-scale physical detection volume, a limit of m_{ß}<155 eV/c^{2} (152 eV/c^{2}) is extracted from the background-free measurement of the continuous tritium beta spectrum in a Bayesian (frequentist) analysis. Using ^{83m}Kr calibration data, a resolution of 1.66±0.19 eV (FWHM) is measured, the detector response model is validated, and the efficiency is characterized over the multi-keV tritium analysis window. These measurements establish the potential of CRES for a high-sensitivity next-generation direct neutrino mass experiment featuring low background and high resolution.

Effect of neutral proteases from blood leukocytes on human platelets.

Two highly purified neutral proteases from human leukocytes i.e. elastase-like protease (ELP) and chymotrypsin-like protease (CLP) do not destroy human platelets since no difference was found in 51Cr liberation from control and enzyme-treated platelets. As with pancreatic chymotrypsin (alpha-CT) ELP does not induce the release of 3H-serotonin while CLP provokes 3H-serotonin secretion, in an enzyme concentration and time dependent fashion. The rate and degree of 3H-serotonin release by CLP is similar to that produced by thrombin. Incubation of platelets at 37 degrees C for 30 min with alpha-CT or ELP renders them resistant to thrombin-releasing activity. Thrombin did not liberate any additional label from platelets which lost over 60% of serotonin during the preceding incubation with CLP. alpha-CT and ELP do not aggregate platelets either in the presence or absence of apyrase. CLP does aggregate platelets suspended in Tyrode buffer without apyrase but not in the presence of apyrase (100 mg/l). The action of alpha-CT, ELP and CLP on washed platelets induces a progressive prolongation of lag phase and a decrease in changes of light transmission during aggregation by thrombin. Similarly to alpha-CT-treated platelets, those subjected to CLP action aggregate in the presence of human fibrinogen. It is concluded that: (1) neutral proteases possibly contribute to development of defects in platelet function in pathological states associated with liberation of leukocyte content into the circulation, (2) CLP similarly to alpha-CT, exposes fibrinogen receptors but in contrast to alpha-CT, CLP aggregates platelets and stimulates serotonin secretion.

Effects of peptides cleaved from human fibrinogen by plasmin on rabbit kidney cells in culture.

Low molecular weight fibrinogen degradation products (LMW-FDP) containing a mixture of dialysable peptides cleaved from human fibrinogen by plasmin are cytotoxic to an established line of rabbit kidney cells and to primary cultures of rabbit kidney cells. The presence of LMW-FDP in a concentration of 50 micrograms/ml during the cell cultivation caused a considerable release of 51Cr from prelabelled cells and inhibited 3H-thymidine and 86Rb uptake. Among three isolated peptides of established primary structure only one, 6D: Ser-Gln-Leu-Gln-Lys-Val-Pro-Pro-Glu-Trp-Lys, induced a significant effect, i.e. it enhanced 3H-thymidine incorporation. Two others, 6A: Ala-Arg-Pro-Ala-Lys and 6E: Thr-Ser-Glu-Val-Lys, did not influence the examined parameters. Hence other components of LMW-FDP must be assumed to be responsible for the cytotoxic effect on kidney cell cultures.

Suppression of cell-mediated immune reactivity by peptides cleaved from human fibrinogen.

Peptides derived from fibrinogen, known from earlier studies to inhibit the stimulation of lymphocytes in vitro and to suppress the humoral immune response in vivo, were investigated for their effect on cell-mediated immune reactivity in mice. An unfractioned mixture of peptides with molecular weights under 3,500 injected intraperitoneally at repeated intervals suppressed the contact hypersensitivity to oxazolone but did not influence the skin inflammatory reaction to croton oil. Local injections of peptides had a stronger effect on contact hypersensitivity. Four 200 micrograms local injections of peptides prior to sensitization abolished the increase in lymph node weight and the uptake of 125I-iododeoxyuridine in the draining lymph node after sensitization. Three previously isolated peptides with vasoactive effects inhibited Con A-stimulated incorporation of 3H-thymidine into spleen cells. The first, a pentapeptide (Ala-Arg-Pro-Ala-Lys), and the second, an undecapeptide (Ser-Glu-Leu-Gln-Lys-Val-Pro-Pro-Glu-Trp-Lys) both with an enhancing effect on microvascular permeability, were more potent than the third, a pentapeptide with slight vasoconstrictive properties (Thr-Ser-Glu-Val-Lys). Cell viability was not altered, as measured by trypan blue exclusion and the release of 86Rb. Accumulating evidence indicates that peptides derived from fibrin may be of importance as modulators of cellular immunoreactivity in a number of clinical conditions.

Anti-inflammatory drugs modulate histamine release from mast cells induced by fibrinogen degradation products.

The products resulting from proteolytic degradation of human fibrinogen (FDP) were found to induce the release of histamine from rat peritoneal mast cells. Low molecular weight, dialysable peptides (FDP) showed the highest dose dependent, histamine releasing activity. Histamine release induced by FDP was effectively inhibited by the gold compound auranofin at a concentration of 10(-5)-10(-7) mol/l and also by the non-steroidal anti-inflammatory drugs BW 755c, timegadine, medosan, naproxen, and aspirin at the higher concentration range of 10(-4)-10(-6) mol/l. It is concluded that the release of histamine from mast cells may be modulated to some extent by anti-inflammatory drugs, especially auranofin, BW 755c and timegadine, a functional property which may be beneficial in the management of joint disease.

[Study on the content of certain elements in retained teeth]. / Badanie zawartosci wybranych pierwiastków w zebach zatrzymanych.

The content of calcium, phosphorus.potassium and zinc was determined in 21 retained canine teeth and in a control group of canine teeth erupted completely. In the measurement the method of X-ray fluorescence was used. The obtained results were subjected to statistical analysis. In relation to control canines the retained teeth contained significantly more calcium and phosphorus and significantly less potassium. No significant differences were found in zinc content.