Zur Frage der „Paralyse-Encephalitis“ Beim Kaninchen Nach Subduraler Injektion von Paralytikerliquor

Ohne Zusammenfassung     

Die Einwirkung der Strahlung auf den Menschen

Ohne Zusammenfassung     

Vascular air embolism: A rare complication of nasal CPAP

Abstract: A preterm infant developed bilateral tension pneumothoraces and extensive vascular air embolism 6 h after being commenced on nasal continuous positive airway pressure (CPAP). Neonatal clinicians should be aware that catastrophic vascular air embolism could occur in infants receiving nasal CPAP, a modality of respiratory support conventionally considered non-invasive and 'safe'.     

Neonatal cholestasis and hypopituitarism

The diagnosis of optic nerve hypoplasia and hypopituitarism must be entertained in infants who present for evaluation of cholestatic jaundice, particularly if there is associated hypoglycaemia and wandering nystagmus. Although the hepatic dysfunction seems to resolve, the long term prognosis of liver disease in optic nerve hypoplasia remains unknown.     

Diplopia in a swimmer due to badly fitting goggles

An unusual effect of badly fitting swimming goggles is described. The goggles pressed on the trochlea of the left eye, interfering with the action of the superior oblique muscle. Diplopia resulted, which took several weeks to resolve.     

Localization of the cleavage site specificity determinant of Haemophilus influenzae immunoglobulin A1 protease genes.

Immunoglobulin A1 (IgA1) proteases are produced by a number of different species of bacteria which cause infection at human mucosal surfaces. The sole substrate of these proteases is human IgA1. Cleavage is within the hinge region of IgA1, although there is variability in the exact peptide bond within the hinge region that is cut by a particular protease. The cleavage site of the Haemophilus influenzae type 1 protease is located four amino acids from the cleavage site of the type 2 enzyme. In this study, the region of the H. influenzae IgA1 protease gene (iga) that determines the cleavage site specificity was localized through the comparison of the type 1 and type 2 genes and the construction and analysis of type 1-type 2 hybrid genes. The hybrid genes were generated by in vivo and in vitro techniques which facilitated the selection and screening of randomly generated hybrids. The cleavage site determinant was found to be within a 370-base-pair region near the amino-terminal coding region, in one of two large areas of nonhomology between the two types of H. influenzae iga genes. DNA sequence analysis of the cleavage site determinant and surrounding regions did not reveal a simple mechanism whereby one enzyme type could be converted to the other type. Comparison of the type 2 gonococcal IgA1 protease gene to the two Haemophilus genes revealed a significant amount of homology around the cleavage site determinant, with the two type 2 genes showing greater homology.     

Inhibition of microbial IgA proteases by human secretory IgA and serum

Microbial IgA proteases cleave human serum IgA1 immunoglobulin, but human secretory IgA is resistant to hydrolysis. We have found this resistance to be due to an inhibition of protease activity that is mediated by the Fab region of secretory IgA. The IgA proteases of the genus Neisseria are more sensitive to inhibition than is the protease of Streptococcus sanguis. There is also a serum inhibitor of Neisseria proteases that co-chromatographs with IgG. Monoclonal (myeloma) human IgG proteins and plasma protease inhibitors such as alpha-1-antitrypsin and alpha-2-macroglobulin do not inhibit. Human sera do not contain inhibitor to S. sanguis protease activity. We conclude that microbial IgA proteases are subject to inhibition by IgA in secretions and IgG in serum, and this activity is most consistent with being an anti-enzyme antibody. The insensitivity of S. sanguis IgA protease to inhibition is unexplained but provides further evidence that the IgA proteases are structurally diverse.     

Loss of antibody activity in human immunoglobulin A exposed extracellular immunoglobulin A proteases of Neisseria gonorrhoeae and Streptococcus sanguis.

Immunoglobulin A (IgA) proteases are extracellular enzymes elaborated by Neisseria gonorrhoeae, N. meningitidis, and Streptococcus sanguis. These enzymes each cleave human IgA1 at a critically situated prolyl-threonyl peptide bond to yield Fab alpha and Fc alpha fragments. To study their effect on the antibody activity of human IgA, we enzymatically digested a group of five human IgA monoclonal immunoglobulins with high-titer rheumatoid factor or cold agglutinin activity and human serum macroamylase, an amylase-IgA complex. In contrast to four control IgM rheumatoid factor monoclonal proteins, whose activity was unaffected by enzyme, gonococcal and streptococcal IgA proteases caused prompt, major reductions of IgA antibody activity to negligible levels and converted macroamylase activity to amylase of normal size, as determined by molecular sieve chromatography. In addition, both enzymes promptly deagglutinated sensitized cells that had been aggregated by IgA rheumatoid factors, indicating that IgA bound to antigen is also susceptible to enzyme cleavage. Fab fragments of Iga protein Chr, a rheumatoid factor, showed essentially no antigen-binding activity despite the high titers observed with the parent protein. These studies emphasize the high degree of specificity of the microbial proteases for IgA and their potential for interfering with antibody activity in the IgA1 subclass.     

Anti B cell targeted immunotherapy for treatment of refractory autoimmune haemolytic anaemia in a young infant

We report the case of an 8 week old infant with fulminant autoimmune haemolytic anaemia refractory to conventional immunomodulating treatment. Massive haemolysis resulted in cardiac decompensation and acute renal failure which necessitated mechanical ventilation and peritoneal dialysis. Rituximab, a chimeric anti-CD20 monoclonal antibody, halted progression of the haemolytic process, but the patient died of acute viral pneumonia and disseminated fungal infection. Earlier introduction of rituximab might have prevented the renal complications. Paediatricians should be aware of this useful therapeutic tool for treatment of refractory autoimmune haemolytic anaemia and balance its use against the risk of potential life threatening infection.