Lack of type 2 T cell-independent B cell responses and defect in isotype switching in TNF-lymphotoxin alpha-deficient mice

TNF is implicated in in vitro Ig production, but its role in vivo is not clearly defined. Our previous studies had shown that TNF-LT alpha double-deficient mice have defective IgM and IgG primary Ab responses to the T cell-dependent (TD) Ag SRBC. We now extend these studies to secondary responses and to T cell-independent (TI) B cell responses. Injections of the TD Ag SRBC did not induce germinal center formation in the spleen of TNF-LT alpha-deficient mice. Associated with the morphologic defect, there was a defective IgG Ab response and a secondary hyper-IgM response to the TD Ag in TNF-LT alpha-deficient mice. The response to the TI Ag type 2 DNP-alanyl-glycyl-glycyl-Ficoll was essentially absent in TNF-LT alpha-deficient mice, while that to the TI Ag type 1 TNP-LPS was significantly reduced only for IgG2b isotype. Transplantation of bone marrow cells from wild-type mice into irradiated TNF-LT alpha-deficient mice restored the formation of splenic germinal centers and corrected the IgM and IgG responses to both TD and TI Ags. These data suggest that TNF and/or LT alpha signaling are critically required for germinal center formation and for the IgM and IgG responses to both TD and TI type 2 Ags.     

Preventing the cardiotoxic effects of anthracyclines with Cardioxane]

An immune response to heparin, which is clinically manifested by the development of thrombocytopenia with or without thrombosis, is stimulated by a complex of heparin with platelet factor 4 (PF4). The primary thrombotic events in patients with heparin-induced thrombocytopenia (HIT) are more frequently venous than arterial. The development of antibodies, however, does not always result in thrombocytopenia or in catastrophic events. The antibodies, which are of the IgG, IgM, and IgA isotypes, can be easily measured by an ELISA that contains a complex of heparin-platelet factor 4 (PF4). Initial antibody formation can be greatly reduced by limiting the exposure to unfractionated heparin or by the use of low-molecular-weight heparin. For those patients who require anticoagulation and who have antibodies to heparin-PF4, danaparoid (Orgaran), a low-molecular weight heparinoid that does not react with the antibodies, is now commercially available; argatroban, a thrombin-specific inhibitor, can also be obtained for compassionate use. The use of these agents during anticoagulation with warfarin is preferable to the simple discontinuation of heparin and intitiation of warfarin, because the latter treatment can result in ongoing thrombosis.     

Stability-beta limit of helical equilibria

Investigation of helical, net longitudinal currentless equilibria with the help of the high-n number ballooning criterion and with the 2D spectral code HERA of m = 1, 2, 3 (2m poloidal node number) internal and external modes suggests that the MHD stability limit of helical equilibria exceeds 〈β〉 = 0.1.     

State of rat liver and spleen DNA after space flight on the "Cosmos-605" satellite

The effect of space flight on the content of nucleic acids and the structure of DNA in the rat liver and spleen was studied. The 22-day exposure did not influence the DNA content in tissues, whereas the RNA content decreased by 14% and 19% in the liver and spleen, respectively. The flight did not induce changes like one-stranded or paired breakages in the DNA structure. Studies of the liver showed a minor trend towards a fall of elastic viscosity of the DNA supermolecular structure (difference between the flight and control rats was statistically insignificant). The above changes in the state of nucleic acids in the liver and spleen were transient.     

Numerical problems associated with the presence of continuous spectra

The discretisation of noncompact operators leading to continuous spectra and resonant absorption is discussed from a physical point of view. Relations between discrete “continua” and validity limits in evolution codes are revealed. In particular, it is demonstrated that spectral pollution might be an unpleasant problem in multidimensional evolution codes. Several open questions concerning present-day computational models are put forward.     

Diagnosis of coronary insufficiency using bicycle ergometry

The bicycle ergometry has proved as screening test for the diagnostics of the latent coronary insufficiency. Taking into consideration well-known prerequisites, indications, contraindications, the criteria of withdrawal and the ECG criteria in coronary insufficiency own results and experiences from an analysis of 1,000 bicycle ergometries are presented and compared with literary data.     

Weanling and adult rats differ in fatty acid and carnitine metabolism during sepsis

Increased oxidation of fat is an important host response to sepsis, and carnitine is essential for long-chain fatty acid oxidation. Because neonates have low levels of carnitine, their ability to respond to a septic insult may be impaired. The purpose of this study was to compare fatty acid and carnitine metabolism in septic weanling (60 to 85 g) and septic adult (285 to 310 g) rats. Sepsis was induced in weanling and adult male Sprague-Dawley rats by cecal ligation and puncture (CLP). The rats were killed 16 hours after CLP or sham operation, and serum glucose, lactate, beta-hydroxybutyrate, fatty acid, carnitine, liver fatty acid, and tissue carnitine levels were measured. The data suggest that during sepsis weanling rats may be more dependent on fatty acid oxidation than adult rats are, as evidenced by their elevated serum fatty acid and acylcarnitine levels, and relative hypoglycemia and hyperketonemia. In addition, although total serum carnitine levels were increased in both adult and weanling septic rats, tissue carnitine levels of weanling rats became significantly depleted during sepsis, unlike in adult rats. This study supports further investigation regarding the role of exogenous carnitine in newborn sepsis.