The cosmic ray shadow of the Moon observed with the ANTARES neutrino telescope

One of the main objectives of the ANTARES telescope is the search for point-like neutrino sources. Both the pointing accuracy and the angular resolution of the detector are important in this context and a reliable way to evaluate this performance is needed. In order to measure the pointing accuracy of the detector, one possibility is to study the shadow of the Moon, i.e. the deficit of the atmospheric muon flux from the direction of the Moon induced by the absorption of cosmic rays. Analysing the data taken between 2007 and 2016, the Moon shadow is observed with 3.5 σ statistical significance. The detector angular resolution for downward-going muons is 0 . 73 ∘ ± 0 . 14 ∘ . The resulting pointing performance is consistent with the expectations. An independent check of the telescope pointing accuracy is realised with the data collected by a shower array detector onboard of a ship temporarily moving around the ANTARES location.

An algorithm for the reconstruction of high-energy neutrino-induced particle showers and its application to the ANTARES neutrino telescope

A novel algorithm to reconstruct neutrino-induced particle showers within the ANTARES neutrino telescope is presented. The method achieves a median angular resolution of [Formula: see text] for shower energies below 100 TeV. Applying this algorithm to 6 years of data taken with the ANTARES detector, 8 events with reconstructed shower energies above 10 TeV are observed. This is consistent with the expectation of about 5 events from atmospheric backgrounds, but also compatible with diffuse astrophysical flux measurements by the IceCube collaboration, from which 2-4 additional events are expected. A [Formula: see text] C.L. upper limit on the diffuse astrophysical neutrino flux with a value per neutrino flavour of [Formula: see text] is set, applicable to the energy range from 23 TeV to 7.8 PeV, assuming an unbroken [Formula: see text] spectrum and neutrino flavour equipartition at Earth.

Sperm whale long-range echolocation sounds revealed by ANTARES, a deep-sea neutrino telescope

Despite dedicated research has been carried out to adequately map the distribution of the sperm whale in the Mediterranean Sea, unlike other regions of the world, the species population status is still presently uncertain. The analysis of two years of continuous acoustic data provided by the ANTARES neutrino telescope revealed the year-round presence of sperm whales in the Ligurian Sea, probably associated with the availability of cephalopods in the region. The presence of the Ligurian Sea sperm whales was demonstrated through the real-time analysis of audio data streamed from a cabled-to-shore deep-sea observatory that allowed the hourly tracking of their long-range echolocation behaviour on the Internet. Interestingly, the same acoustic analysis indicated that the occurrence of surface shipping noise would apparently not condition the foraging behaviour of the sperm whale in the area, since shipping noise was almost always present when sperm whales were acoustically detected. The continuous presence of the sperm whale in the region confirms the ecological value of the Ligurian sea and the importance of ANTARES to help monitoring its ecosystems.

Antibody binding to endothelial and epithelial antigens triggers pig-to-rabbit xenograft rejection and its absence results in atypical complement deposition

In pig-to-rabbit kidney xenograft (PRKX), endothelial antigen determinants (EAD) are immediately recognized by IgG and IgA, while IgM does not react with them. The purpose of this study was to investigate the different roles of IgG, IgA, IgM, and complement in the hyperacute rejection of a PRKX model. Nine isolated Landrace pig kidneys were each perfused with 10 ml normal New Zealand rabbit serum. Perfusates (serum A) were collected after discarding the first 0.5 ml. Serum A and rabbit complement were then incubated for 30 min with frozen sections of normal pig kidney. After washing with buffer solution all the specimens were treated for immunohistochemistry. Three frozen sections of normal Landrace pig kidney and three samples of normal New Zealand rabbit serum were used as controls. Immunohistochemical analysis of the nine perfused kidneys demonstrated IgG, IgA and C3 deposition on the peritubular and glomerular vascular endothelium. No IgM reactivity was shown. In the frozen sections exposed to serum A, immunofluorescence showed minimal IgG, IgA and C3 reactivity while IgM deposition was clearly evident on the tubular epithelium. Immunofluorescence of frozen sections exposed to rabbit complement, done by fluorescein-labeled goat anti-rabbit C3 antibodies were positive only in the glomerular endothelium. The same rabbit complement was active in antibody dependent cytotoxicity on human T cells. Our results indicated that in the PRKX model, IgG and IgA acted as preformed antibodies recognizing endothelial EAD. IgM did not bind to any endothelial molecules, but recognized antigens located on the brush border of the tubular epithelium. Furthermore, in this model, absence of antigen-antibody complexes resulted in atypical complement deposition.

Serum protein immunogenicity: implications for liver xenografting

The objectives of this study were threefold: (i) assess immunogenicity of donor plasma proteins following hepatic xenotransplantation, (ii) identify potential immunogens, and (iii) consider the implications of antibody formation against these plasma proteins in xenograft survival. We studied liver and heart xenografts in a concordant combination, hamster to rat. All grafts were examined at necropsy for evidence of rat immunoglobulin G (IgG) deposition. Cardiac xenografts were placed in recipients who had, or had not, been sensitized with hamster serum. Hepatic xenografts were placed in naive recipients to see if antibodies to hamster serum proteins could be eluted from the rejecting organ. Sera of immunized rats were examined for the presence of anti-hamster antibodies by immunoelectrophoresis and by Western blotting following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) separation of hamster serum. Antibodies in sera of immunized rats were compared with those eluted from rejecting livers. Candidate antigens were identified by tandem mass spectrometry, sequence analysis, and reference to protein databases. Results showed that sera of immunized rats recognized a minimum of four different antigens in hamster serum by immunoelectrophoresis, and a minimum of seven by the more sensitive SDS-PAGE Western blot. IgG eluted from rejecting livers bound three of seven candidate antigens recognized by sera of the immunized animals. Sequence analysis searches revealed proteinase inhibitors in each of the three SDS-PAGE bands common to the above samples. All of these candidate proteinase inhibitor immunogens share a common catabolic fate, uptake via the lipoprotein-related protein (LRP/alpha 2-macroglobulin receptor (CD91). Sensitization to hamster serum proteins hastened cardiac xenograft rejection in 30-50% of recipients (depending on sensitization protocol). Vascular deposition of rat IgG occurred in all rejecting xenografts. Antibody binding to proteinase inhibitors could disturb their functional activity and contribute to the pathogenesis of delayed xenograft rejection.

Serum protein immunogenicity: implications for liver xenografting

The objectives of this study were threefold: (i) assess immunogenicity of donor plasma proteins following hepatic xenotransplantation, (ii) identify potential immunogens, and (iii) consider the implications of antibody formation against these plasma proteins in xenograft survival. We studied liver and heart xenografts in a concordant combination, hamster to rat. All grafts were examined at necropsy for evidence of rat immunoglobulin G (IgG) deposition. Cardiac xenografts were placed in recipients who had, or had not, been sensitized with hamster serum. Hepatic xenografts were placed in naive recipients to see if antibodies to hamster serum proteins could be eluted from the rejecting organ. Sera of immunized rats were examined for the presence of anti-hamster antibodies by immunoelectrophoresis and by Western blotting following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) separation of hamster serum. Antibodies in sera of immunized rats were compared with those eluted from rejecting livers. Candidate antigens were identified by tandem mass spectrometry, sequence analysis, and reference to protein databases. Results showed that sera of immunized rats recognized a minimum of four different antigens in hamster serum by immunoelectrophoresis, and a minimum of seven by the more sensitive SDS-PAGE Western blot. IgG eluted from rejecting livers bound three of seven candidate antigens recognized by sera of the immunized animals. Sequence analysis searches revealed proteinase inhibitors in each of the three SDS-PAGE bands common to the above samples. All of these candidate proteinase inhibitor immunogens share a common catabolic fate, uptake via the lipoprotein-related protein (LRP/alpha 2-macroglobulin receptor (CD91). Sensitization to hamster serum proteins hastened cardiac xenograft rejection in 30-50% of recipients (depending on sensitization protocol). Vascular deposition of rat IgG occurred in all rejecting xenografts. Antibody binding to proteinase inhibitors could disturb their functional activity and contribute to the pathogenesis of delayed xenograft rejection.

Early recipient-donor switch of the complement type after liver xenotransplantation

Liver transplantation is an immunological peculiarity with respect to the resistance of the graft to humoral rejection. We undertook a kinetic analysis of molecules involved in humoral rejection for a period of one week following xenografting in the hamster to rat model system. A complement-dependent lymphocytotoxicity test (CDC) was used to detect anti-donor antibodies in the recipient rats. Complement was studied by two methods. Function of the classical complement pathway was evaluated with a hemolytic assay, and C3 was measured by radial immunodiffusion. Conversion of the major plasma proteins from recipient to donor profile was studied by zone electrophoresis on agarose. CDC showed antibody titers rose during the first week post-transplantation, and they were of complement-activating isotypes. Zone electrophoresis showed almost complete replacement of rat C3 by hamster C3 within 72 hours. Hemolytic assay of complement on day 6 post-transplant showed serum of the xenograft recipients could lyse erythrocytes sensitized with rat antibody with 80% of efficiency of normal rat serum. Our data show the effector molecules for humoral rejection, rat antibodies with anti-hamster specificity and a functional complement cascade, were present within the first week following transplantation. Rapid conversion of serum complement to hamster proteins maintains compatibility with the species-specific membrane inhibitors of complement activation expressed by the xenografted hepatocytes, and could limit complement-mediated damage.

Tacrolimus pretreatment attenuates preexisting xenospecific immunity and abrogates hyperacute rejection in a presensitized hamster to rat liver transplant model

In the hamster to rat liver transplant model, we determined the efficacy of tacrolimus in attenuating natural xenospecific humoral immunity and in abrogating the hyperacute liver rejection that is produced by presensitizing the Lewis rat recipient. Hamster livers, transplanted orthotopically into naive rats (controls), were rejected with animal death after 6.4.+/- 0.5 (SD) days. The infusion on (day -6) of 1.5 x 10(7) hamster hepatocytes, or of 1.5 x 10(8) nonparenchymal cells (NPC), resulted in hyperacute rejection and death in < or = 1.9 days. However, when the rats were pretreated with 1 mg/kg/day tacrolimus from days -6 to -1, survival of non-presensitized animals was prolonged to 25 +/- 20 days and that of recipients presensitized with hamster hepatocytes to 36 +/- l6 days or with NPC to 32 +/- 1.7 days. The tacrolimus pretreatment significantly reduced the hamster-specific complement-dependent cytotoxic antibodies response directed to liver NPC but not to lymph node cell targets. These observations suggest that the prolongation of survival by appropriately timed treatment with this T cell directed drug model is caused by the inhibition of humoral as well as cellular xenograft rejection.

Functional cooperation of xenoproteins after hamster-to-rat liver transplantation: With particular reference to hamster C3 and secretory component for rat IgA

Long-term survival after hamster-to-rat liver xenotransplantation has provided the opportunity to study the posttransplantation source of major serum proteins and the functional consequences of several different receptor-ligand interactions, where one or the other is a xenogeneic protein. We report here that serum albumin, α-1-antitrypsin, complement component 3, and other acute phase reactants switch from recipient to donor origin during the first week after transplantation while serum immunoglobulins remain largely that of recipient. Despite the disparate source of complement (hamster) and immunoglobulins (rat), these two proteins were able to cooperate effectively to produce lysis of sheep red blood cells. Moreover, rat IgA was successfully processed by hamster hepatocytes and biliary epithelial cells, being present in the bile of successful liver xenograft recipients within one day after transplantation. The ability of these liver xenograft recipients to survive long-term in conventional and viral-free animal facilities without grossly obvious morbidity or unusual susceptibility to stress, suggests that xenogeneic proteins are able to successfully interact with several different physiologic systems in the hamster-to-rat combination.

Donor species complement after liver xenotransplantation. The mechanism of protection from hyperacute rejection

Hamster hearts transplanted into stable rat recipients of hamster livers (OLT rats) were hyperacutely rejected after transfer with unaltered rat antihamster hyperimmune serum (HS). This was followed by immediate liver xenograft rejection in 4 of 5 rats. In contrast, simple heat inactivation of the rat HS resulted in prolonged survival of hamster hearts to 25 days without deterioration effect in the liver xenografts. This effect was species-specific because third-party mouse heart grafts in OLT rats were hyperacutely rejected in minutes if either active or heat inactivated antimouse HS was given. In cytotoxicity experiments, the complement in OLT serum produced weak lysis of hamster lymphocytes, while efficiently doing so with mouse cell targets. Because normal hamster serum caused no lysis at all of hamster target cells, the residual low-grade lysis of OLT serum was possibly being mediated by extrahepatic sources of rat C. In conclusion, the homology of C and target cells represents a mechanism of protection that the liver confers to other organs, and that is mostly easily seen in xenografts but may be allospecifically operational with allografts as well within the limits of MHC restriction.

Xenotransplantation rejection is antibody-mediated in both sensitized and nonsensitized recipients

This study analyzes the mechanisms involved in xenotransplantation rejection between closely related species. Hamster hearts were transplanted heterotopically into both normal rats and rats previously sensitized by the transfusion of donor blood. Sequential ultrastructural and immunohistochemical analyses were performed on the grafts, spleens, and sera. The data obtained support the view that induced antibodies directed against the xenograft endothelium play a very important role in producing graft damage. Moreover, the demonstration of antibodies against myocyte determinants suggests that it is possible, in this particular model, that the antiendothelial antibodies are not the only ones involved in the injury process.

Humoral and cellular immunopathology of hepatic and cardiac hamster-into-rat xenograft rejection. Marked stimulation of IgM++bright/IgD+dull splenic B cells

Normal Lewis rat serum contains antibodies (IgM > IgG) that bind to hamster leukocytes and endothelial cells. Transplantation of either the heart or liver from hamster rat results in release of hamster hematolymphoid cells from the graft, which lodge in the recipient spleen (cell migration), where recipient T- and B-cell populations initiate DNA synthesis within one day. There is marked stimulation of splenic IgM++(bright)/IgD+(dull) B cells in the marginal zone and red pulp, which account for 48% of the total splenic blast cell population by 4 days after liver transplantation. CD4+ predominant T-cell proliferation in the splenic periarterial lymphatic sheath and paracortex of peripheral lymph nodes occurs almost simultaneously. The effector phase of rejection in cardiac recipients is dominated by complement-fixing IgM antibodies, which increase daily and result in graft destruction in 3 to 4 days, even in animals treated with FK506. In liver recipients, combined antibody and cellular rejection, associated with graft infiltration by OX8+ natural killer, and fewer W3/25+ (CD4) lymphocytes, are responsible for graft failure in untreated recipients at 6 to 7 days. FK506 inhibits the T-cell response in liver recipients and significantly prolongs graft survival, but does not prevent the rise or deposition of IgM antibodies in the graft. However, a single injection of cyclophosphamide 10 days before transplantation effectively depletes the splenic IgM++(bright)/Ig+(dull) cells and in combination with FK506, results in 100% survival of both cardiac and hepatic xenografts for more than 60 days. Although extrapolation of morphological findings to functional significance is fraught with potential problems, we propose the following mechanisms of xenografts rejection. The reaction initially appears to involve primitive host defense mechanisms, including an IgM-producing subpopulation of splenic B cells and natural killer cells. Based on the reaction and distribution of OX8+ and W3/25+ cells, antibody-dependent cell cytotoxicity and delayed-type hypersensitivity responses seem worthy of further investigation as possible effector mechanisms. Effective control of xenograft rejection is likely to require a dual pharmaceutical approach, one to contain T-cell immunity and another to blunt the primitive B-cell response.

Long-term survival of heart and liver xenografts with splenectomy and FK 506

We have reported that while hamster-to-rat liver xenograft survival is prolonged by FK 506, hamster hearts undergo humoral rejection under this immunosuppressant.1 Because the spleen has been shown to be one of the main sources of xenoantibodies,2 ,3 and in vivo experiments have demonstrated that splenectomy (Spx) is able to increase the efficacy of various immunosuppressive agents after xenotransplantation,4 –6 we combined Spx with FK 506 to test whether survival of the intractable cardiac xenografts is prolonged, and of liver xenografts improved.

[Dumbbell neurogenic tumors in children]

Dumbbell neurogenic tumours are unusual neoplasms in the pediatric age group. Six cases all in children under 10 years of age, have been reviewed with respect to diagnosis, management and results. Neurologic deficits have been found in 4 patients only; in the other 2 cases the tumours were occasionally discovered. Myelograms, sometimes associated with CT scan, allowed a correct diagnosis in all the patients. Initial treatment consisted in all the cases in laminectomy or laminotomy with total excision of the extradural tumour. The primary paravertebral tumours have been removed in one patient during the same neurosurgical operation, and in other three patients at a second stage. Two patients did not require the second operation: one recovered after chemotherapy and the other died few days after the first surgical procedure. Five patients are still alive: two, who had the tumour occasionally discovered, are free from disease; among the other 3 patients, presenting with neurological symptoms, 1 is free from disease without neurological symptoms and 2 have still long lasting sequelae. The authors emphasize the role of early diagnosis to prevent neurologic abnormalities and to achieve better results.

Orthotopic transplantation of the liver in children with biliary atresia and polysplenia syndrome: report of two cases

Biliary atresia is the most common indication for liver transplantation in infants and children, despite the advent of the Kasai operation. Coexisting anomalies, which have been noted in up to 27% of patients with biliary atresia, may form an association known as the "polysplenia syndrome," which includes (1) polysplenia, (2) midgut malrotation, (3) preduodenal portal vein, (4) absent prerenal inferior vena cava with azygos continuation, (5) situs inversus, (6) symmetric liver, (7) hepatic arterial anomalies, and (8) bilobed right lung with hyparterial bronchus. Two of 31 patients undergoing orthotopic liver transplantation for biliary atresia following failed portoenterostomy over the past 11 years manifested the polysplenia syndrome with absent prerenal inferior vena cava. The clinical course of these patients, constellation of anomalies, and technical adjustments required to perform liver transplantation are described. We do not believe that these complex congenital anomalies preclude liver transplantation.

An approach to the study of the biological activity of Eschscholtzia californica Cham

Pharmacological activities of Eschscholtzia californica Cham. are not yet well known. The aim of this work is to verify the pharmacological properties and to get a first identification of the active principles.

Comparison of combined portal-arterial versus portal perfusion during liver procurement

PAP of harvested livers is routinely used to minimize parenchymal anoxia during storage. PP is compared with PAP to evaluate the relative reliability of PAP. Sixty female Landrace pigs were used for 30 OLTs. Group 1 livers underwent PP, whereas group 2 livers were treated with PAP. The cold ischemic time was less than 120 minutes for both groups, with no warm ischemia. Intraoperative and 24-hour postoperative biochemical, coagulation, and histocytological data were analyzed. Morphological studies of cellular damage were based on the percentage of CVD and KP and classified as light, moderate, and severe damage. Data, at closing, were compared by using Fisher's test (group 1 v group 2,P = 0.003 for light damage and P = .04 for severe damage; first postoperative day for group 1 v group 2, P = .133 for light damage and P = .25 for severe damage. Blood samples at closing and 24 hours postoperatively showed significant differences between groups 1 and 2: At closing for groups 1 and 2, respectively: AST, 968.9 +/- 742.7 and 327.4 +/- 174.7 IU/L (P less than .001); ALT, 63.1 +/- 40.3 and 20.3 +/- 5.3 IU/L (P less than .001); AP, 292.2 +/- 107.1 and 139.5 +/- 45.3 IU/L (P less than .001); and 24 hours postoperatively for groups 1 and 2, respectively: AST, 1,664.9 +/- 917.8 and 419.3 +/- 230.9 IU/L (P less than .001): ALT. 180.4 +/- 28.9 and 66.4 +/- 17.5 IU/L (P less than .001); AP, 602.1 +/- 153.3 and 255.7 +/- 116.3 IU/L (P less than .01). Comprehensively, the results reflect a better perfusate distribution of the PAP livers compared with PP ones: uniform organ preservation, faster metabolic recovery, and reduced postoperative mortality.

Liver replacement with reduced size donor organs

End stage liver disease in children can be treated with orthotopic liver transplantation (OLT). Nevertheless, the expansion of this therapy in Europe has been limited because of the shortage of appropriate size-matched donors. One possible technical solution is the OLT of a liver graft previously reduced in size by in situ resection preceding the harvesting procedure. To study the impact of this technique we examined two different operative procedures performed on Landrace pigs. Group 1 consisted of 20 standard donor/recipient weight matched OLT. In group 2, 15 OLT were performed using right lateral and medial lobes (55% of the original donor liver). The donor/recipient weight ratio in the group was 2:1. Cold ischemia times were 90 +/- 16 min for group 1 and 98 +/- 9 min for group 2. It is emphasized that in contrast to all the other reports using resected liver grafts for OLT, the donor resection in our study was always performed in situ under normothermic conditions, preceding the harvesting procedure. This was designed to reduce the cold ischemia time. No significant technical problems were encountered. The biochemical results of group 2 pigs compared to group 1 demonstrate an analogous, postoperative course. This might be explained by regenerative stimuli acting on the resected liver tissues and enhancing their metabolic function. These data support the conclusion that resected adult donor liver grafts may be used for pediatric transplant recipients.