Observation of Seven Astrophysical Tau Neutrino Candidates with IceCube.

We report on a measurement of astrophysical tau neutrinos with 9.7 yr of IceCube data. Using convolutional neural networks trained on images derived from simulated events, seven candidate ν_{τ} events were found with visible energies ranging from roughly 20 TeV to 1 PeV and a median expected parent ν_{τ} energy of about 200 TeV. Considering backgrounds from astrophysical and atmospheric neutrinos, and muons from π^{±}/K^{±} decays in atmospheric air showers, we obtain a total estimated background of about 0.5 events, dominated by non-ν_{τ} astrophysical neutrinos. Thus, we rule out the absence of astrophysical ν_{τ} at the 5σ level. The measured astrophysical ν_{τ} flux is consistent with expectations based on previously published IceCube astrophysical neutrino flux measurements and neutrino oscillations.

Search for Relativistic Magnetic Monopoles with Eight Years of IceCube Data.

We present an all-sky 90% confidence level upper limit on the cosmic flux of relativistic magnetic monopoles using 2886 days of IceCube data. The analysis was optimized for monopole speeds between 0.750c and 0.995c, without any explicit restriction on the monopole mass. We constrain the flux of relativistic cosmic magnetic monopoles to a level below 2.0×10^{-19} cm^{-2} s^{-1} sr^{-1} over the majority of the targeted speed range. This result constitutes the most strict upper limit to date for magnetic monopoles with ß≳0.8 and up to ß∼0.995 and fills the gap between existing limits on the cosmic flux of nonrelativistic and ultrarelativistic magnetic monopoles.

Search for Unstable Sterile Neutrinos with the IceCube Neutrino Observatory.

We present a search for an unstable sterile neutrino by looking for a resonant signal in eight years of atmospheric ν_{µ} data collected from 2011 to 2019 at the IceCube Neutrino Observatory. Both the (stable) three-neutrino and the 3+1 sterile neutrino models are disfavored relative to the unstable sterile neutrino model, though with p values of 2.8% and 0.81%, respectively, we do not observe evidence for 3+1 neutrinos with neutrino decay. The best-fit parameters for the sterile neutrino with decay model from this study are Δm_{41}^{2}=6.7_{-2.5}^{+3.9} eV^{2}, sin^{2}2θ_{24}=0.33_{-0.17}^{+0.20}, and g^{2}=2.5π±1.5π, where g is the decay-mediating coupling. The preferred regions of the 3+1+decay model from short-baseline oscillation searches are excluded at 90% C.L.

Strong Constraints on Neutrino Nonstandard Interactions from TeV-Scale ν_{µ} Disappearance at IceCube.

We report a search for nonstandard neutrino interactions (NSI) using eight years of TeV-scale atmospheric muon neutrino data from the IceCube Neutrino Observatory. By reconstructing incident energies and zenith angles for atmospheric neutrino events, this analysis presents unified confidence intervals for the NSI parameter ε_{µτ}. The best-fit value is consistent with no NSI at a p value of 25.2%. With a 90% confidence interval of -0.0041≤ε_{µτ}≤0.0031 along the real axis and similar strength in the complex plane, this result is the strongest constraint on any NSI parameter from any oscillation channel to date.

Observation of high-energy neutrinos from the Galactic plane.

The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, is unknown. Because of deflection by interstellar magnetic fields, cosmic rays produced within the Milky Way arrive at Earth from random directions. However, cosmic rays interact with matter near their sources and during propagation, which produces high-energy neutrinos. We searched for neutrino emission using machine learning techniques applied to 10 years of data from the IceCube Neutrino Observatory. By comparing diffuse emission models to a background-only hypothesis, we identified neutrino emission from the Galactic plane at the 4.5σ level of significance. The signal is consistent with diffuse emission of neutrinos from the Milky Way but could also arise from a population of unresolved point sources.

Evidence for neutrino emission from the nearby active galaxy NGC 1068.

A supermassive black hole, obscured by cosmic dust, powers the nearby active galaxy NGC 1068. Neutrinos, which rarely interact with matter, could provide information on the galaxy's active core. We searched for neutrino emission from astrophysical objects using data recorded with the IceCube neutrino detector between 2011 and 2020. The positions of 110 known gamma-ray sources were individually searched for neutrino detections above atmospheric and cosmic backgrounds. We found that NGC 1068 has an excess of [Formula: see text] neutrinos at tera-electron volt energies, with a global significance of 4.2σ, which we interpret as associated with the active galaxy. The flux of high-energy neutrinos that we measured from NGC 1068 is more than an order of magnitude higher than the upper limit on emissions of tera-electron volt gamma rays from this source.

Plasminogen activator and its inhibitor in cancer patients treated with tumor necrosis factor.

BACKGROUND: We noted the presence of plasma fibrin degradation products in patients treated with recombinant human tumor necrosis factor (TNF) in a phase I trial. PURPOSE: To further define this observation, we investigated the effects of TNF on the fibrinolytic system in patients entered in the same trial. METHODS: In the 14 patients studied, fibrinolytic parameters were measured by analyzing blood samples for tissue plasminogen activator and inhibitor at 0, 1, 2, 4, 6, and 18-24 hours after initiation of TNF treatment. We used a chromogenic substrate method to determine activity of plasminogen activator and its inhibitor and an enzyme-linked immunosorbent assay (ELISA) to determine levels of antigen (tissue-type plasminogen activator). Molecular weight was determined by zymographic assay. RESULTS: TNF treatment was associated with tissue-type plasminogen activator induction within 1 hour of TNF initiation. The plasminogen activator produced was consistent with tissue-type plasminogen activator derived from endothelium as evidenced by molecular weight analysis and ELISA. Moreover, induction of plasminogen activator inhibitor occurred following the release of tissue-type plasminogen activator, and our data suggest a dose-response effect for TNF. At high doses (i.e., 200 and 240 micrograms/m2), there was a more rapid and prolonged release of plasminogen activator inhibitor, which had an inverse relationship with the level of antigenic tissue-type plasminogen activator. Zymographic analysis showed urokinase-type plasminogen activator activity in 13 of 14 patients. In three patients, simultaneous measurements of white blood cells and tissue-type plasminogen activator revealed a temporal association between the TNF-associated rapid granulocytopenia at 30 minutes after TNF initiation and release of tissue-type plasminogen activator antigen. CONCLUSIONS: The results suggest a positive association between TNF and rapid induction of plasminogen activator activity that is consistent with an endothelial product. It is possible that, at high doses, TNF may interact directly with vascular endothelium, leading to rapid and prolonged production of plasminogen activator inhibitor. There was a dose-response effect between TNF and release of tissue-type plasminogen activator. The release of tissue-type plasminogen activator was preceded by granulocytopenia, which may indicate an association between a proposed TNF-induced granulocyte-endothelial interaction in vivo and release of tissue-type plasminogen activator. IMPLICATIONS: These findings demonstrating the effects of TNF on the fibrinolytic system can be analyzed further in experimental systems to determine the implications for use of this agent as a biological response modifier in cancer therapy.

Decreased helper/suppressor cell ratios after treatment with factor VIII and IX concentrates and fresh frozen plasma.

The immunologic status of three groups of multiply transfused asymptomatic patients was evaluated. These included five with acquired inhibitors to factor VIII treated with both factor VIII and factor IX concentrates (Group A), seven with hemophilia B treated with factor IX concentrate (Group B), and six with hemophilia B treated with fresh frozen plasma (Group C). Mean helper/suppressor T cell ratios (+/- SEM) for the three groups were 0.72 +/- 0.09, 1.35 +/- 0.18, and 1.37 +/- 0.12, respectively. All three differed significantly (p less than 0.01) from the control mean ratio of 2.22 +/- 0.16. In addition, the mean ratio of Group A patients was significantly different (p less than 0.01) from those of Groups B and C. An inverted ratio (less than 1.00) was found in all Group A patients and only one Group B patient. Increased IgG levels were found in 80, 57, and 50 percent of each group, respectively. These immunologic findings bear a striking resemblance to those of the acquired immunodeficiency syndrome (AIDS) of homosexuals, intravenous-drug abusers, Haitian immigrants, and factor VIII concentrate-treated hemophiliacs. Transmission via a blood-borne infectious agent seems likely.

Systemic effects of tissue plasminogen activator-associated fibrinolysis and its relation to thrombin generation in orthotopic liver transplantation.

Orthotopic liver transplantation is frequently associated with hyperfibrinolysis, the origin and clinical relevance of which is largely unknown. In 20 orthotopic liver transplantations, we studied the occurrence and systemic effects of hyperfibrinolysis. Severe fibrinolysis was defined to be present when the euglobulin-clot lysis time and the whole-blood-clot lysis time, as measured by thrombelastography, were shorter than 60 and 90 min, respectively, at some time during the operation. Based on these criteria, 7 patients had minimal fibrinolysis (group I), and 13 patients had severe fibrinolysis (group II). In group II a gradual increase of tissue-type plasminogen activator (t-PA) activity was seen during the anhepatic stage, followed by an "explosive" increase immediately after graft reperfusion (P = 0.0004, compared with group I), and a reduction of plasminogen activator inhibitor (PAI) activity. Plasma degradation products of fibrinogen and fibrin increased parallel to t-PA activity, and levels were significantly higher at 45 min after graft reperfusion in group II compared with group I (P less than 0.04). Thrombin-antithrombin III complexes showed an identical steady increase in both groups, indicating that increased t-PA activity was not related to thrombin formation. A combination of increased endothelial release and reduced hepatic clearance may have caused the increased t-PA activity. The t-PA-associated destruction of fibrinogen and fibrin after graft reperfusion is consistent with the clinical signs of severe oozing often seen in this period. These observations may have important clinical implications for the treatment of bleeding in patients undergoing orthotopic liver transplantation.

The relation of preoperative coagulation findings to diagnosis, blood usage, and survival in adult liver transplantation.

A group of 70 adults with end-stage liver disease received 87 homologous liver transplants from 7/11/81 and 7/11/83. The recipients fell into the following diagnostic categories: postnecrotic cirrhosis (PNC) in 22, primary biliary cirrhosis (PBC) in 18, cancer or neoplasia (CA) in 11, sclerosing cholangitis (SC) in 8 and miscellaneous (MISC) in 11. Survival for six months or longer was 46%: survival by group was PBC = 67%, CA = 55%, PNC = 45%, SC = 25%, and MISC = 18%. Preoperative coagulation profiles were evaluated on 64 of the 70 first transplant patients by assigning a score derived from one point per abnormality in each of 8 tests. Mean coagulation abnormality scores (CAS) were strikingly elevated in the PNC and MISC groups. Mean intraoperative blood product usage was 43 units of RBCs, 40 units of fresh frozen plasma (FFP), 21 units of platelets, and 9 bags of cryoprecipitate. Direct correlations were found between CAS and RBC usage (+0.454, P = less than .001), CAS, and survival of 6 months or longer (-0.281, P = less than .02), and RBC usage and survival (-0.408, P = less than .001). These findings indicate that the degree of coagulation abnormality and the type of liver disease may be predictive of intraoperative blood usage and survival in liver transplantation in adults.

Plasma fibronectin levels in clinical disease states and after cryoprecipitate infusion.

Fibronectin levels were measured in 151 hospitalized patients with liver disease, sepsis, malignancy, leukemia, and following trauma or surgery, using heterologous precipitating antibody in an immunoassay. The mean (+/- S.E.M.) in 25 controls was 0.95 +/- 0.06 U/ml, with females, 0.83 +/- 0.07 U/ml, lower than males, 1.09 +/- 0.09 U/ml. Mean fibronectin levels were decreased in all disease groups except in obstructive liver disease. The reduced levels in hepatocellular disease and the restoration of levels to normal after orthotopic liver transplantation in patients with hepatocellular disease supports the theory that hepatic synthesis contributes significantly to plasma fibronectin levels. Following cryoprecipitate infusion in four hemophiliac patients, plasma fibronectin levels rose to 32% to 45% of the levels predicted. In patients with reduced fibronectin and poor clinical response to standard treatment (antibiotics, chemotherapy), cryoprecipitate infusions may raise the levels of fibronectin and, perhaps, contribute to clinical improvement.

Hepatitis C testing. Comparison of Ortho's EIA and RIBA II tests in 1,182 patients undergoing primary liver transplantation.

Plasma samples from 1,182 patients undergoing primary liver transplantation were tested for anti-hepatitis C (HCV) virus by two methods: Ortho HCV ELISA Test System (EIA) and Chiron RIBA HCV Test System (RIBA II). The EIA results, 0 or +, were recorded first, followed by RIBA results, N = negative, P = positive, or I = indeterminate. Concordant results--0N, + P, + I--were found in 1,076 (91%), and discordant results were found in 106 (9%). The EIA optical density did not relate to concordant or discordant results. Band patterns were described by stating the band position (1, 2, 3, or 4) and inserting a dash (-) if no band was visualized. Most + P samples fell into two patterns: 47% showed all four bands, pattern 1234, and 15% showed the two-band pattern, 34. When the EIA was negative, 0P, the opposite was seen: 8% showed the 1234 pattern and 81% showed the 34 pattern. There were 226 samples that formed bands (+ P, 149; 0P, 31; + I, 15; 0I, 31). The frequency of bands was as follows: 4, 32%; 3, 31%; 2, 19%; and 1, 18%. Band 2 and the EIA test detected antibodies to the same c100-3 fragment and showed 74% concordance. No explanation is apparent for the lower concordance rate here than that between the EIA test and bands 3 = 96% or 4 = 88%. The EIA and RIBA II tests, together with positive liver function tests and abnormal tissue pathologic findings, provide a basis for the diagnosis of HCV.

General surgery in adult hemophiliacs.

From 1976 to 1984, 23 operations were performed on 22 patients with hemophilia (18 patients with factor VIII and four with factor IX deficiency). Elective procedures included resection of abdominal aortic aneurysm, liver transplantation, vagotomy/pyloroplasty, insertion of Mousseau-Barbin tube, colectomy, cholecystectomy, inguinal herniorrhaphy (four patients), colonoscopy/polypectomy, mediastinoscopy, arteriovenous fistula for dialysis, anal fistulectomy, and miscellaneous skin and soft-tissue procedures (five patients). Emergency operations were appendectomy (two patients), repair of bleeding liver biopsy site, and repair of an incarcerated inguinal hernia. There were two deaths (9%) within 30 days of operation, neither directly caused by the coagulopathy. Four patients had bleeding after surgery, which was treated with additional cryoprecipitate or factor concentrate. There were no nonhemorrhagic complications. Before operation, appropriate replacement therapy with factor VIII concentrate, cryoprecipitate, or fresh-frozen plasma was provided. Coagulation factor levels were measured before operation and monitored daily after operation. Generally, factor levels were raised to at least 1.0 U/ml and maintained at greater than 0.5 U/ml for 7 to 14 days after operation. However, when patients were treated with fresh-frozen plasma, plasma exchange was performed and factor levels of approximately 0.35 U/ml were achieved before surgery. We conclude that operations in patients with hemophilia can be accomplished safely with careful monitoring of coagulation factor levels and appropriate replacement therapy.

Protein C and protein S plasma levels in patients with lipodermatosclerosis and venous ulceration.

Lipodermatosclerosis of the lower extremity, with or without ulceration, is a common manifestation of severe venous disease and the result of sustained venous hypertension. The latter is generally a sequela of deep vein thrombosis. Factors that enhance clot formation or impair fibrinolysis contribute to the pathogenesis of venous disease. It is already established that faulty fibrinolysis may play a pathogenic role in patients with venous disease. We examined the possibility that patients with venous disease have abnormally low plasma levels of proteins C and S, two proteins whose deficiencies have been reported to cause an increased frequency of thromboembolic disease. Using immunologic and functional assays for plasma proteins C and S, we found that 4 (21%) of 19 patients with lipodermatosclerosis and leg ulcers had abnormally low levels of protein C or protein S. One of 7 patients with lipodermatosclerosis without ulceration had a profoundly depressed level of protein C and a history of cerebral stroke at a young age. Plasma levels of protein C were normal in five patients with arterial insufficiency severe enough to cause leg ulceration. We conclude that abnormally low plasma levels of proteins C and S may be found in patients with lipodermatosclerosis and venous ulceration. As with the abnormally low fibrinolytic activity in these patients, our findings indicate a possible propensity for increased thrombotic disease.

Peripheral retinal neovascularization (Eales disease) associated with the factor V Leiden mutation.

PURPOSE: To illustrate a case of peripheral retinal neovascularization (Eales disease) in a patient who tested positive for the factor V Leiden mutation. METHODS: A 42-year-old woman had a 1-week history of blurred vision in her right eye. Her medical history was remarkable for a cerebrovascular accident. Ophthalmoscopy of the right eye disclosed a mild vitreous hemorrhage and a ridge of retinal neovascularization in the temporal periphery. The left fundus showed evidence of temporal retinal ischemia. A laboratory evaluation for hypercoagulability was positive for factor V Leiden mutation. RESULTS: Peripheral scatter laser photocoagulation was applied to the ischemic retina, and the neovascularization regressed. The patient began taking warfarin sodium to prevent further thrombotic events. CONCLUSION: A laboratory evaluation for coagulopathy, including the factor V Leiden mutation, should be added to the examination of patients with Eales disease, especially individuals with a history of a previous thrombotic event.

Arterial thromboembolic events in patients with the factor V Leiden mutation.

BACKGROUND: The factor V Leiden mutation affects 6% of the United States population and is known to be associated with venous thrombosis. We identify, herein, 30 individuals with the Leiden mutation and known arterial thromboembolic events. METHODS: The factor V mutation was assessed using polymerase chain reaction. RESULTS: In the 16 patients sustaining a cerebrovascular accident, the mean age was 44.1 and 11 (69%) were younger than 50. Similarly, the 13 patients presenting with an acute myocardial infarction were relatively young with a mean age of 45.5, and 9 (65%) patients presented at less than 50 years of age. Radiographic information was available for 19 patients in this study. No significant arterial atherosclerotic disease was demonstrated in 18 (95%) of these patients. CONCLUSIONS: This study demonstrates an association between the factor V Leiden mutation and the development of unexplained arterial thromboembolic events, especially in younger patients without existing atherosclerotic disease.

Adenotonsillectomy in children with von Willebrand disease.

OBJECTIVE: To review the effectiveness of a perioperative management protocol and our experience with a large population of patients with von Willebrand disease (vWD) who require adenotonsillar surgery (T&A). DESIGN: A retrospective review of the medical records of all patients having the diagnosis of vWD who underwent T&A between January 1, 1992, and July 31, 1996. SETTING: A tertiary care, university-based children's hospital. INTERVENTIONS: Patients having a preoperative diagnosis of vWD received a single intravenous dose of desmopressin acetate, 0.3 pg/kg, approximately 20 minutes before the induction of anesthesia. Beginning January 15, 1994, a standard management protocol involving the postoperative administration of fluids and electrolytes was followed. MAIN OUTCOME MEASURES: Operative blood loss and the incidence of postoperative bleeding and of hyponatremia. RESULTS: Of approximately 4800 patients who underwent T&A during the study period, 69 patients had a diagnosis of vWD. All 67 patients identified preoperatively received desmopressin; 2 were identified by postoperative workup as a result of excessive surgical bleeding. Minimal immediate postoperative bleeding was noted in 7 patients (10%), but none required intervention. Delayed bleeding occurred in 9 patients (13%); all were readmitted to the hospital for observation, 4 (6%) requiring operative cauterization. Substantial postoperative hyponatremia occurred in 3 patients, and 1 patient had seizure activity. Symptomatic hyponatremia has been avoided since a protocol of fluid and electrolyte administration was instituted. CONCLUSIONS: Although T&A can be performed safely in patients with vWD, it is not without an increased risk of postoperative hemorrhage. The administration of desmopressin has been reported to reduce the risk of bleeding, but it is not without risk. A protocol for fluid and electrolyte management is recommended.

Low-dose aspirin and prednisone treatment of pregnancy loss caused by lupus anticoagulants.

The objective of this study was to ascertain the complications and the efficacy of low-dose aspirin (LDA) and prednisone therapy in women with pregnancy loss and "lupus anticoagulants" (LAC). During the period 1985 to 1993, 255 patients with two or more pregnancy losses (RPL) were tested for LAC with an activated partial thromboplastin time (aPTT) and a tissue thromboplastin inhibition index (TTI, normal value < 1.3). The diagnosis of LAC was established if two TTI values were > or = 1.3 or if a prolonged aPTT was measured in the patient's plasma that did not correct to normal by 1:1 mixing with normal plasma. We excluded patients with RPL who had only anticardiolipin antibodies. We treated 28 pregnancies in 21 women with LDA/prednisone for RPL associated with LAC. Therapy with LDA/prednisone was initiated as soon as a viable pregnancy was diagnosed. Therapy was continued until delivery in all but one case. Prednisone dose was minimized by measuring TTI and aPTT every 2 weeks and adjusting the dosage to maintain a TTI < or = 1.2 and to correct the aPTT to less than 36 seconds. Among the 28 pregnancies there were four (14%) first-trimester spontaneous abortions and four (14%) second-trimester fetal deaths. Of 20 surviving neonates (72%), seven were delivered after 37 weeks and 13 before 37 weeks (mean 35.9 +/- 2.3 weeks, range 31.5 to 40.4 weeks). Pre-term premature rupture of membranes occurred in three pregnancies, hypertensive disorders in six, and four small-for-gestational-age neonates were delivered (two stillborn). Mean birth weight of 20 surviving neonates was 2736 +/- 763 gm (range 900 to 3920 gm). Mean daily prednisone dose in 20 live births was 24.1 +/- 8.5 (SD) mg (range 11.3 to 49.3 mg/day) with mean duration of LDA/prednisone therapy of 185 +/- 40 days (range 97 to 223 days). Maximum prednisone dose was 60 mg/day (mean 36.8 +/- 12.7 mg/day). Only one serious maternal complication of LDA/prednisone therapy was observed. One neonate had talipes equinovarus that resolved without surgical therapy. LDA/prednisone therapy seemed effective and reasonably well tolerated in this population. These findings should be confirmed in a prospective, controlled investigation if such a trial can be organized and performed.

Evaluation and treatment of the plastic surgical patient having a potential to bleed.

The clinical plastic surgeon needs to be able to determine which of his or her patients are low risk and which of his or her patients require additional tests. Which patients can be operated on today, and which patients need to be delayed and possibly treated preoperatively? After a review of the literature, we present these guidelines: 1. Take a good history. 2. Stratify the risk to the patient. 3. Test as indicated. a. Don't necessarily rely on the bleeding time. b. Be aware of the high false-positive rate of coagulation tests. 4. Be mindful of the effects of certain medicines. 5. "Surgical" bleeding is the most common cause of bleeding and should prompt reoperation if coagulation tests are negative. 6. Consult a hematologist early as questions arise, particularly in patients stratified to moderate- and high-risk groups.