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.

Current technical surgical practice of emergency appendicectomy: a cross-sectional survey of surgical registrars in the UK.

INTRODUCTION: Appendicectomy remains one of the most commonly performed procedures in general surgery. The aim of this study was to explore variation in operative techniques of an appendicectomy among surgical registrars in England. MATERIALS AND METHODS: An anonymised survey was sent out to surgical registrars in the UK via email and social media. Subgroup analyses were performed comparing respondents based on their level of seniority and subspecialty background. RESULTS: A total of 168 respondents completed the survey, of whom 77.4% (130/168) were specialty trainees years 3-8 and 44.6% (75/168) were colorectal trainees. The majority (98.8%) preferred a laparoscopic approach to appendicectomy. Overall, 73.2% opted to use diathermy to divide an uninflamed mesoappendix. Half of the respondents (50%) preferentially used diathermy to control the appendicular artery, followed by 44% preferring use of metal or polymeric clips. The appendicular stump was most often secured with Endoloops (85.7%) when removing a macroscopically uninflamed appendix but less readily used in the visibly inflamed appendix (75.6%, p = 0.01). Colorectal and upper gastrointestinal registrars were more likely to use diathermy on the mucosa of the appendix stump compared with other subspecialties (p = 0.03). The majority (82.1%) of respondents extracted the appendix via a retrieval bag. Regarding skin closure, most respondents (69%) adopted absorbable subcuticular sutures. Preferential duration of postoperative antibiotic use following appendicectomy for complicated appendicitis varied among the respondents. CONCLUSION: There are similarities and differences across surgical registrars in terms of technical practice in appendicectomy, partially attributed to prior experience and training.

Allogeneic stem cell transplantation from matched related and unrelated donors in thalassemia major patients using a reduced toxicity fludarabine-based regimen.

The only radical cure for thalassemia major patients today is the replacement of the defective hematopoietic system by allogeneic stem cell transplantation (allo-SCT). The major obstacles for the application of allo-SCT even from matched family members have been the transplant-related morbidity and mortality and graft failure that is usually associated with the recurrence of the thalassemia hematopoiesis. The outcome of allo-SCT from HLA-identical family donors is largely dependent on the age of the recipient as well as on pretransplant parameters reflecting the degree of organ damage from iron overload. In this study we report our experience of allo-SCT from matched related and unrelated donors, using a reduced toxicity conditioning consisting of fludarabine, busulfan or more recently busulfex and antithymocyte globulin, in a cohort of 20 patients with thalassemia major. The regimen-related toxicity was minimal, while the incidence of acute grade II-IV and chronic GVHD was 25 and 25%, respectively. With a median follow-up period of 39 months (range: 5-112 months) the overall survival was 100%, while thalassemia-free survival was 80%. Although the results of our study look promising, larger cohorts of patients and prospective clinical trials are required to confirm the benefits of our approach as a possible better alternative to the existing protocols.

Nucleotide sequence and transcriptional regulation of the yeast recombinational repair gene RAD51.

The RAD51 gene of Saccharomyces cerevisiae is required both for recombination and for the repair of DNA damage caused by X rays. Here we report the sequence and transcriptional regulation of this gene. The RAD51 protein shares significant homology (approximately 50%) over a 70-amino-acid with the RAD57 protein (J.A. Kans and R.K. Mortimer, Gene 105:139-140, 1991), the product of another yeast recombinational repair gene, and also moderate (approximately 27%), but potentially significant, homology with the bacterial RecA protein. The homologies cover a region that encodes a putative nucleotide binding site of the RAD51 protein. Sequences upstream of the coding region for RAD51 protein share homology with the damage response sequence element of RAD54, an upstream activating sequence required for damage regulation of the RAD54 transcript, and also contain two sites for restriction enzyme MluI; the presence of MluI restriction sites has been associated with cell cycle regulation. A 1.6-kb transcript corresponding to RAD51 was observed, and levels of this transcript increased rapidly after exposure to relatively low doses of X-rays. Additionally, RAD51 transcript levels were found to that of a group of genes involved primarily in DNA synthesis and replication which are thought to be coordinately cell cycle regulated. Cells arrested in early G1 were still capable of increasing levels of RAD51 transcript after irradiation, indicating that increased RAD51 transcript levels after X-ray exposure are not solely due to an X-ray-induced cessation of the cell cycle at a period when the level of RAD51 expression is normally high.

Enhanced lymphoid cell recovery after bone marrow transplantation: correlation with the presence of costimulatory antibodies in serum.

We describe a patient with T cell deficiency who underwent bone marrow transplantation (BMT) from an HLA-identical brother. The patient's white blood cell count recovered with exceptional rapidity post-BMT: after 7 to 9 days it rose sharply to 98x10(9) cells/L, 76% of which were mononuclear leukocytes. It then decreased, and a second peak was observed 250 days post-BMT. Lymphocytes from both peaks displayed a phenotype of mature T cells together with characteristics of a constitutively activated state; that is, they 1) exhibited high levels of tyrosine-phosphorylated T cell receptor (TCR) zeta chain, 2) spontaneously secreted IL-2, 3) expressed activation specific cell surface markers, and 4) were unresponsive to in vitro stimuli. The increased cell counts in both peaks correlated with the presence of anti-lymphocytic antibodies in the patient's serum, which reacted with peripheral blood lymphocytes (PBLs) both from the donor and from unrelated individuals. These antibodies were present before BMT and reappeared post-BMT. Variable number tandem repeats analysis revealed that the patient's PBLs were chimeras for up to 2 years post-BMT. This finding could explain the newly synthesized post-BMT anti-lymphocytic antibodies and the appearance of the second WBC peak during that period. The patient's anti-lymphocytic antibodies displayed costimulatory activity, enhancing the in vitro proliferation of normal T cells suboptimally activated via the TCR. The unique characteristics of these antibodies could explain the enhanced T cell recovery observed post-BMT as well as the constitutive activation state of these cells. Furthermore, such antibodies may eventually facilitate development of a therapeutic method for inducing enhanced post-BMT recovery.

Low-intensity conditioning is sufficient to ensure engraftment in matched unrelated bone marrow transplantation.

OBJECTIVE: Matched unrelated bone marrow transplantation (BMT) for patients with hematological malignancies is associated with a high incidence of transplant-related complications due to high doses of chemoradiotherapy administered pre-BMT to ensure engraftment. The aim of this study was to investigate the feasibility of low-intensity conditioning for BMT from matched unrelated donors. MATERIALS AND METHODS: Sixteen patients with hematologic malignancies underwent non-T-cell-depleted BMT following a low-intensity conditioning regimen consisting of fludarabine monophosphate 30 mg/m(2)/day for 6 days, busulfan 4 mg/kg/day for 2 days, anti-T lymphocyte globulin 10 mg/kg/day for 4 days. Seven of the patients suffered from chronic myelogenous leukemia, four from acute lymphoblastic leukemia, four from acute myelogenous leukemia, and one from Ki-1 non-Hodgkin's lymphoma. Three of the patients had secondary leukemia and two were post-autologous BMT (ABMT). All patients were transplanted from fully matched unrelated donors. RESULTS: Fifteen of the 16 patients had 100% donor chimerism; no graft rejection was observed. None of the patients developed >Grade II veno-occlusive disease, sepsis, multiorgan failure, or renal or pulmonary toxicity. Four patients died posttransplant; one of thrombocytopenia and severe hemorrhagic cystitis, one of central nervous system toxicity, one of Grade IV graft-vs-host disease, and one following relapse (9 months post-BMT). Survival and disease-free survival at 36 months are 75% (95% confidence interval 46-90%) and 60% (95% confidence interval 30-80%), respectively. CONCLUSION: These results indicate that low-intensity conditioning is sufficient to ensure stable engraftment of bone marrow grafts in a matched unrelated setting.

Engraftment of marrow allografts treated with Campath-1 monoclonal antibodies.

We have analyzed the factors associated with engraftment in 216 recipients of T-cell depleted allogeneic HLA identical sibling marrow transplants using Campath 1 monoclonal antihuman lymphocyte (CD52) antibodies. The patient population consisted of 168 patients with hematologic malignancies, 26 with severe aplastic anemia (SAA), and 22 with hemoglobinopathies, half of whom received marrow treated in vitro with Campath-1M (IgM) and half received marrow with Campath-1G (IgG2b isotype). Patients with durable engraftment had fast hematopoietic recovery: SAA patients reached ANC > 0.5 x 10(6)/L on Day 14; those with leukemia attained ANC > 0.5 x 10(6)/L on Days 18, 17, and 15 for ANLL, ALL and CML respectively, while patients with thalasemia reached ANC > 0.5 x 10(6)/L on Day 21. Overall, 24 patients (17 with leukemia, 4 with SAA, and 3 with thalassemia) suffered graft failure: 10 patients (all grafted with Campath-1M) rejected their grafts, while 14 others (9 grafted with Campath-1M, and 5 with 1G isotype) never engrafted (p = 0.009). Multivariate analysis revealed that neither pretransplant protocol, nor stage of disease or type of antibody used, donor sex and ABO match had any impact on engraftment. The variables favorably associated with engraftment were older age (p = 0.030, RR = 1.016) and CFU-GM number (p = 0.013, RR = 1.001). Patients with ANLL or SAA had a better chance to engraft (p = 0.027, RR = 1.400; and p = 0.003, RR = 2.677, respectively) compared to patients with thalassemia (p = 0.001, RR = 0.551). A higher concentration of Campath-1 antibody in vitro and in vivo adversely affected engraftment. Our data show that satisfactory engraftment can be achieved in patients transplanted with Campath-1 treated marrow allografts. However, despite the measures undertaken to prevent rejection, graft failure still poses a problem. Further pretransplant immunosuppression and perhaps more selective T-cell depletion may reduce the increased graft failure in these patients.

Serotonin transporter polymorphisms predict response inhibition in healthy volunteers.

Serotoninergic transmission is reliably implicated in inhibitory control processes. The aim of this study was to test the hypothesis if serotonin transporter polymorphisms mediate inhibitory control in healthy people. 141 healthy subjects, carefully screened for previous and current psychopathology, were genotyped for the 5-HTTLPR and rs25531 polymorphisms. Inhibitory control was ascertained with the Stop Signal Task (SST) from the Cambridge Neuropsychological Test Automated Battery (CANTAB). The triallelic gene model, reclassified and presented in a biallelic functional model, revealed a dose-dependent gene effect on SST performance with Individuals carrying the low expressive allele had inferior inhibitory control compared to high expressive carriers. This directly implicates serotonin transporter polymorphisms (5-HTTLPR plus rs25531) in response inhibition in healthy subjects.

First position wobble in codon-anticodon pairing: amber suppression by a yeast glutamine tRNA.

A 2.4-kb fragment of DNA isolated from the Saccharomyces cerevisiae genome was found to suppress amber mutations when its carrier plasmid was present in high copy number. A 1.2-kb subclone of this fragment was sufficient to confer suppressor activity. Sequencing has established that this fragment carries a normal glutamine tRNA gene. Deletion of this tRNA gene from the subclone resulted in the loss of suppressor activity. The tRNAGln has the anticodon CUG that normally recognizes the glutamine codon CAG. We propose that suppression occurs via an inefficient readthrough of the UAG amber stop codons during translation. Such readthrough requires wobble in the first position of the codon.

Bacterial pneumonia in recipients of bone marrow transplantation. A five-year prospective study.

Bacterial pneumonia as an important complication of bone marrow transplantation (BMT) has not been subjected to comprehensive analysis. Two hundred fifty-five consecutive allogeneic and autologous BMT recipients, ranging in age from 1 month to 53 years, were prospectively followed for 3 days to 3 years (median, 108 days) for development of bacterial pneumonia. Etiology, place acquired, chest radiography, and outcome were recorded and the association between bacterial pneumonia and demographic and clinical variables was analyzed. Thirty-seven (15%) patients experienced 52 episodes of bacterial pneumonia: onset of 13 episodes occurred within 30 days after transplantation, 10 episodes occurred on days +31 to +100, and 29 episodes occurred thereafter. Bacterial pneumonia was the terminal event or contributed to fatal outcome in 8 patients (22% of bacterial pneumonia cases, 3% total study population). Mortality due to hospital-acquired pneumonia (6/21) was significantly higher than (P = 0.03). Bacterial pathogens were identified in 27 (52%) episodes. During the first 100 days after BMT, hospital-acquired Gram-negative bacteria predominated, caused mainly by Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter lwoffi, and Enterobacter cloacae. After day +100, community-acquired, Gram-positive bacteria predominated, particularly Streptococcus pneumoniae. Haemophilus influenzae occurred periodically. Considering all episodes, significant association was found between bacterial pneumonia and veno-occlusive disease (VOD) (P < 0.01) and chronic graft-versus-host disease (GVHD) (P < 0.02). For culture-positive episodes, the association between bacterial pneumonia and VOD was significant (P < 0.001) and borderline for acute GVHD (P = 0.07). It is concluded that VOD and GVHD are positively associated with post-BMT bacterial pneumonia. Its incidence, etiology, risk factors, and outcome are important considerations in its prevention and treatment.

Bone marrow transplantation from a cadaveric donor.

A 2.5-year-old girl with neurogenic Gaucher's disease was transplanted with donor bone marrow from her HLA-compatible 12-year-old brother whose marrow was harvested 30 min post-mortem, after he suffered a severe head and neck injury. The marrow was stored in liquid nitrogen for 30 days prior to infusion. The post-transplantation period was uneventful with good engraftment and no signs of graft-versus-host disease. Currently, 6 months post-allogeneic bone marrow transplantation (alloBMT), analysis of both bone marrow and blood samples by PCR documented only cells of donor origin. This case demonstrates the feasibility of cadaveric marrow as a source of donor cells. To our knowledge, this patient is the only survivor of alloBMT from a cadaveric donor.

Immunotherapy of hematologic malignancies and metastatic solid tumors in experimental animals and man.

Following engraftment of donor hematopoietic cells and induction of host-versus-graft tolerance, immunocompetent lymphocytes of donor origin can induce graft-versus-leukemia (GVL) and graft-versus-tumor (GVT) effects. Engraftment of allogeneic bone marrow cells can be accomplished following non-myeloablative conditioning while possibly controlling graft-versus-host disease (GVHD). GVL and GVT effects may thus be successfully accomplished following non-myeloablative stem cell transplantation (NST) as shown by data derived from experimental animals and man.

Total lymphoid irradiation, anti-lymphocyte globulin and Campath 1-G for immunosuppression prior to bone marrow transplantation for aplastic anemia after repeated graft rejection.

Allogeneic BMT for severe aplastic anemia is associated with a significant rate of graft rejection, especially in patients who have been previously transfused. We report a child with aplastic anemia who rejected donor marrow twice despite adequate immunosuppression as part of the conditioning therapy but engrafted successfully following combined administration of three modalities of immunosuppression: antithymocyte globulin, total lymphoid irradiation and the monoclonal antibody Campath-1G. Restriction fragment length polymorphism studies > 1 year after BMT show full donor hematopoiesis with no evidence of autologous recovery.

Cytosine arabinoside as a major risk factor for Streptococcus viridans septicemia following bone marrow transplantation: a 5-year prospective study.

The incidence and clinical course of nosocomial septicemia with Streptococcus viridans was evaluated prospectively in 242 consecutive bone marrow transplant (BMT) recipients throughout their 15-213 days' (median 47) hospitalization, including 4-58 days (median 18) of neutropenia. Initial empiric therapy for febrile neutropenia consisted of mezlocillin, gentamicin and cefazolin; glycopeptide was excluded. S. viridans septicemia occurred in 23/209 (11%) subjects with underlying malignant disease, and only during neutropenia with concomitant mucositis: in 20 subjects (four with ampicillin-resistant strains), S. viridans septicemia occurred at onset of febrile neutropenia, 1-5 days (median 4.5) post-BMT. All survived with an uncomplicated clinical course. Thus, glycopeptide seems unnecessary in the initial empiric antibiotic regimen. The other three subjects demonstrated S. viridans septicemia (two with ampicillin-resistant strains) on day 11 post-BMT; two died. The major risk identified was cytosine arabinoside administration in the conditioning regimen (P < 0.01).

Antibody response to a two-dose regimen of influenza vaccine in allogeneic T cell-depleted and autologous BMT recipients.

Induction of protective hemagglutination-inhibition (HI) antibodies in response to influenza virus vaccine and the effectiveness of two doses versus a single dose of vaccine were studied in 48 BMT recipients. The patients were 1-50 years old (median 21 years), 33 with malignant and 15 with non-malignant disease. Thirty-five of the patients underwent allogeneic, T lymphocyte-depleted, BMT and 13, autologous BMT. Nine patients had GVHD at initial immunization. The time interval from BMT to influenza vaccination ranged from 2 to 82 months (median 14.5 months). Two doses of vaccine, administered 1 month apart, consisted of trivalent influenza subunit inactivated vaccine with the following strains: A/Singapore/6/86 (H1N1), A/Sichuan/2/87 (H3N2), and B/Beijing/1/87. There was a statistically significant association between development of protective antibody level (> or = 1:40) and the time interval between BMT and initial vaccination (p < or = 0.001). Regression analysis revealed that longer time interval between the BMT and immunization was positively correlated with seroconversion (a fourfold or greater rise in titers). In the presence of GVHD, there was reduced seroconversion to H1N1, but not to H3N2 or B strains. Influenza vaccination within the first 6 months following BMT was totally ineffective. The efficacy of the vaccine was similar to that described in non-immunocompromised hosts initiated 2 years following BMT. As, overall, specific response was only marginally enhanced by the second dose of vaccine, its indication is questionable.

Immune response to polio vaccination in bone marrow transplant recipients.

Following a small outbreak of poliomyelitis which occurred in the summer of 1988 in Israel, two sequential doses of inactivated polio vaccine (IPV) were administered to 42 bone marrow transplant (BMT) recipients (aged 2-50 years) who were 6-96 months (median 16 months) after transplantation. Prior to vaccination, only 68-80% patients (n = 42) had protective (greater than or equal to 4) antibody levels against the three serotypes of poliovirus, compared with 92-96% (n = 25) before BMT (p = 0.02 for types 1 and 3). After the second dose of IPV, 89-98% (n = 27) of the recipients had protective antibody levels. The pre-vaccination antibody titers were lower than before BMT (p = 0.006, 0.0007 and 0.0008 for types 1,2 and 3, respectively). After the first dose of IPV, antibody titers rose in the 42 patients (p = 0.002, 0.043 and 0.002 for types 1, 2 and 3, respectively) and following the second dose, a further increase in antibody levels was noted. Regression analysis revealed that graft-versus-host disease, pre-BMT polio antibody titers, age and type of transplantation (allogeneic versus autologous) were significant explanatory variables for the specific antibody levels, while the time lapse between BMT and vaccination, and primary disease proved of no significance. Vaccination against poliovirus after BMT is advocated, as it reinstates and raises the lost specific humoral immunity.

Osteopetrosis: a single centre experience of stem cell tranisplantation and prenatal diagnosis.

Malignant osteopetrosis (MOP) is an autosomal recessive disease in which osteoclast dysfunction results in excessive bone deposition and early infant death. Thirteen children suffering from MOP from four related families all belonging to one Bedouin tribe, were studied. The disease was diagnosed as early as at a few days postnatal to 5 months. Nine children underwent BMT, four of whom are still alive; one is blind and two have markedly reduced vision. Four children who did not undergo BMT died between 4 and 6 months of age. Recently, the gene for MOP has been mapped for this Bedouin tribe allowing prenatal diagnosis. Seven pregnancies were subsequently prenatally diagnosed and two fetuses were found to be affected. Pregnancy was electively terminated in one case. In the other case the parents refused and after establishing the diagnosis, the newborn was transplanted at the age of 7 days.

The role of recombinant human erythropoietin in the treatment of thalassemia.

The rationale for treatment with recombinant human erythropoietin (rHuEPO) in thalassemia came from studies in baboons, thalassemic mice and in erythroid cultures. The results demonstrated an increase in gamma globin synthesis and consequently in fetal Hb (Hb F) resulting in improvement in erythropoietic parameters. In addition, endogenous serum Epo levels in various forms of thalassemia were inconsistent and not related to the severity of the anemia. Therefore, several preliminary studies with rHuEPO were performed, mainly on patients with beta thalassemia intermedia. The results indicate: a) a significant, dose-related (500 u/kg to 1000 u/kg x 3/week) increase in thalassemia erythropoiesis without changes in % of Hb F, MCV and MCH, mainly in splenectomized patients; b) the minimum effective dose is 500 u/kg x 3/week; c) there were no major side effects during the continuous treatment period of 9 months. In order to improve both quantitative and qualitative thalassemia erythropoiesis, several trials were undertaken combining rHuEPO with hydroxyurea (HU), which is known to increase % Hb F, MCV and MCH without a major effect on Hb levels. The designed trial included 3 to 6 months of HU alone (20 mg/kg x 4/week), or with rHuEPO alone (500 u/kg x 3/week or 375 u/kg x 2/week) or a combination of the two drugs. The results show an additive effect of the two drugs, in some of the patients. It is not known whether the addition of oral iron to rHuEPO is warranted for maximal erythropoietic response. The major limiting factor in designing large scale clinical trials is the relatively high cost of the drug. Nevertheless rHuEPO alone or in combination with other Hb F modulating drugs may have a positive effect in thalassemia with resulting improvement in the quality of life.