New Constraint on the Local Relic Neutrino Background Overdensity with the First KATRIN Data Runs.

We report on the direct search for cosmic relic neutrinos using data acquired during the first two science campaigns of the KATRIN experiment in 2019. Beta-decay electrons from a high-purity molecular tritium gas source are analyzed by a high-resolution MAC-E filter around the end point at 18.57 keV. The analysis is sensitive to a local relic neutrino overdensity ratio of η<9.7×10^{10}/α (1.1×10^{11}/α) at a 90% (95%) confidence level with α=1 (0.5) for Majorana (Dirac) neutrinos. A fit of the integrated electron spectrum over a narrow interval around the end point accounting for relic neutrino captures in the tritium source reveals no significant overdensity. This work improves the results obtained by the previous neutrino mass experiments at Los Alamos and Troitsk. We furthermore update the projected final sensitivity of the KATRIN experiment to η<1×10^{10}/α at 90% confidence level, by relying on updated operational conditions.

Bound on 3+1 Active-Sterile Neutrino Mixing from the First Four-Week Science Run of KATRIN.

We report on the light sterile neutrino search from the first four-week science run of the KATRIN experiment in 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are analyzed by a high-resolution MAC-E filter down to 40 eV below the endpoint at 18.57 keV. We consider the framework with three active neutrinos and one sterile neutrino. The analysis is sensitive to the mass, m_{4}, of the fourth mass state for m_{4}^{2}≲1000 eV^{2} and to active-to-sterile neutrino mixing down to |U_{e4}|^{2}≳2×10^{-2}. No significant spectral distortion is observed and exclusion bounds on the sterile mass and mixing are reported. These new limits supersede the Mainz results for m_{4}^{2}≲1000 eV^{2} and improve the Troitsk bound for m_{4}^{2}<30 eV^{2}. The reactor and gallium anomalies are constrained for 100<Δm_{41}^{2}<1000 eV^{2}.

Improved Upper Limit on the Neutrino Mass from a Direct Kinematic Method by KATRIN.

We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic end point at 18.57 keV gives an effective neutrino mass square value of (-1.0_{-1.1}^{+0.9}) eV^{2}. From this, we derive an upper limit of 1.1 eV (90% confidence level) on the absolute mass scale of neutrinos. This value coincides with the KATRIN sensitivity. It improves upon previous mass limits from kinematic measurements by almost a factor of 2 and provides model-independent input to cosmological studies of structure formation.

Familial Mediterranean Fever in Armenian population.

Familial Mediterranean Fever (FMF) is an inherited, recessively transmitted inflammatory condition usually occurred in populations from Mediterranean descent (Armenian, Arab, Jewish, Greek, Turkish and Italian populations). Identification of MEFV gene mutations has been of tremendous help for early diagnosis of most cases. The frequency of FMF is different. The prevalence of heterozygous carriers of one of the mutations of MEFV gene is as high as 1 in 5 healthy individuals in Armenia. Genetic testing of this rare Mendelian disorder (MIM no 249100) is efficient for early and prenatal diagnosis of the disease, especially for atypic cases, for carrier screening and pregnancy planning since certain mutations have been shown to have significant correlation with renal amyloidosis (RA), the most severe possible manifestation of FMF. Also genetic testing is very important for colchicine therapy correction. Twelve MEFV mutations are identified in 7000 Armenian FMF patients. Investigation of MEFV mutations in FMF patients (heterozygotes, homozygotes and compound heterozygotes) in comparison with healthy individuals has revealed the most frequent mutations and genotypes, and the information was received about the heterozygous carriers and genotype-phenotype correlation. In heterozygote carriers the most prevalent and severe cases are caused by the presence of a single M694V mutation. Our results could confirm that the MEFV gene analysis provides the first objective diagnostic criterion for FMF (characterisation of the two MEFV mutated alleles in more than 90% of the patients). Molecular testing is also used to screen the MEFV gene for mutations in patients with a clinical suspicion of FMF. We also demonstrated the unfavourable prognostic value of the M694V homozygous genotype, and provided the first molecular evidence for incomplete penetrance and pseudo-dominant transmission of the disease. Overall, these data, which confirm the involvement of the MEFV gene in the development of FMF, should be essential in clinical practice, leading to new ways of managment and treatment of FMF patients.

[Antibodies to myocardial muscle fiber sarcolemmic antigens in rheumatism and other heart diseases]. / Izuchenie antitel k asntigenam sarkolemmy myshechnogo volokna miokarda pri revmatizme i drugikh zabolevaniiakh serdtsa.

The work discusses the results of studying by indirect immunofluorescence and the passive hemagglutination test antibodies to sacolemma antigens of myocardial muscle fiber in patients with rheumatic fever as compared to those in patients with affection of myocardium of nonrheumatic origin. The frequency of the detection of antibodies to sarcolemma antigens in sera of patients with rheumatic fever by immunofluorescence correlates with the activity of the process. No differences were revealed in the frequency of detection of antibodies reacting with sarcolemma in rheumatic fever and in other heart diseases in the active phase. Antibodies to sarcolemma antigens contained in HCL-extracts from human myocardium preparations, which are detected in the passive hemagglutination test are revealed significantly more often in sera of patients with rheumatic fever. Control experiments with IgG fractions obtained from whole sera were conducted to remove any possible nonspesific reactions of tissue extracts with the sera tested.

[Ordering of antibodies, that react with cardiac muscle fiber and interstitial connective tissue antigens, in different immunoglobulin classes]. / Prinadlezhnost' antitel, reagiruiushchikh s antigenami myshechnogo volokna i interstitsial'noi soedinitel'noi tkani serdtsa k raznym klassam immunoglobinov.

Sera of patients suffering from rheumatic diseases and myocarditis were examined on the sections of human and bovine myocardial tissue by indirect immunofluorescence with the use of pure IgG antibodies or monospecific sera against IgG, IgA and IgM. It was shown that antibodies reacting with different myofibers and interstitial connective tissue of the heart belong to the main immunoglobulin classes (IgG, IgA and IgM). There was a significant predominance of IgG antibodies as shown by the frequency of their detection and by the titer height. The predominance of antibodies to certain classes of immunoglobulins did not correlate with a specific disease entity. The frequency of detecting antibodies to a certain immunoglobulin class was in good agreement with the time of the disease onset. Moreover, the frequency of positive reactions due to IgG, IgA, and IgM antibodies correlated with the level of the appropriate immunoglobulins in the test sera.

[Reactions of normal human and rabbit immunoglobulins with heart valve fibroblasts]. / Reaktsii normal'nykh immunoglobulinov cheloveka i krolika s fibroblastami klapanov serdtsa.

It was demonstrated using the indirect immunofluorescent technique that normal human and rabbit sera, and IgG isolated from them intensively reacted with fibroblasts of human and bovine heart valves. The results obtained with Fab and Fc fragments of IgG sugges that this reaction is due to the Fc region of the IgG molecule and related to the presence of the Fc receptor on fibroblasts of heart valves.