A Case of Keraunoparalysis: A Bolt from the Blue.

Keraunoparalysis is a catastrophic but fortunately totally reversible neuroparalysis of the limbs occurring due to a lightning strike. One such case with transient right hemiparesis along with a brief account of the pathophysiology of this unique neurologic problem has been presented here.

Determination of IgG- and IgM-class antibodies to mumps virus by solid-phase enzyme immunoassay.

An indirect enzyme immunoassay (EIA) for the determination of IgG and IgM antibodies to mumps virus is described. Viral antigens and control antigens were adsorbed onto polystyrene microtiter plates, and antibodies attached to the antigens were detected by subsequent binding of commercial peroxidase-labeled antibodies to the heavy chains of human IgG and IgM immunoglobulins. A comparison of antibody titers obtained by the EIA and by indirect immunofluorescence test showed a close concordance between these two tests, with EIA, however, being more sensitive. Occasional cross-reactions between mumps and parainfluenza antibodies were detected in the IgG antibody test but not in the IgM antibody test. In sera from 84 patients with mumps infection, all cases were diagnosed by the EIA IgM antibody assay, 96% from the first serum specimen. Mumps was diagnosed by complement fixation (CF) in 71% of these cases: unclear or erroneous results with parainfluenza titer increases in 10% and no diagnosis in 18% of the cases. The EIA IgM antibody assay was thus better than the CF test for the diagnosis of acute mumps infection.

A "reverse" solid-phase radio-immuno-assay for IgM-antibodies to hepatitis A virus.

A "reverse"solid-phase radio-immuno-assay for IgM antibodies to hepatitis A virus (HAV) was developed. Anti-human IgM immunoglobulins were bound on the wells of polyvinylchloride microtiter plates. Serum specimens were incubated in the anti-human IgM coated wells and bound IgM antibodies were then assayed for antigen specificity by subsequent incubations with HAV antigen and 125I-labelled human anti-HAV IgG. The test showed a high sensitivity and specificity for anti-HAV IgM antibodies. No false-positive reactions were observed either in the sera from patients with hepatobiliary disorders other than HAV infection or in the sera containing both rheumatoid factor and anti-HAV IgG antibodies. In acute HAV infections specific IgM antibodies were present already in the first specimens taken within a few days after the onset of jaundice. The persistence of the IgM antibodies was from 4 to 6 months. IgM antibody titers up to 1,000,000 were observed in the acute phase of HAV infection. In routine diagnostic work the titration of the sea was not necessary, since a reliable qualitative result was obtained by testing the sera in a single dilution of 1:100. A similar "reverse" immuno-assay principle may be adaptable for the diagnostic determination of IgM antibodies to different viral and microbial antigens.

Solid-phase enzyme immunoassay for determination of antibodies to cytomegalovirus.

A solid-phase enzyme immunoassay for the determination of immunoglobulin H (IgG) and IgM antibodies to cytomegalovirus is described. The enzyme immunoassay gave reliable and consistent results which were in concordance with those obtained by the complement fixation test and the indirect immunofluorescence test. Antibodies to herpes simplex and varicella-zoster viruses did not interfere in the enzyme immunoassay for cytomegalovirus IgM antibodies. In a few patients with IgM antibodies to Epstein-Barr virus, cytomegalovirus IgM antibodies were also detected. False-positive cytomegalovirus IgM antibody results were observed in sera containing both the rheumatoid factor and cytomegalovirus IgG antibodies. This rheumatoid factor interference was overcome by the absorption of sera with polymerized human gamma globulin. The absorption did not affect true cytomegalovirus IgM antibody titers. Also described is a simple enzyme immunoassay that makes possible a more sensitive detection of the rheumatoid factor than the latex agglutination test.

Biosynthesis of proline in Pseudomonas aeruginosa. Partial purification and characterization of gamma-glutamyl kinase.

A gamma-glutamyl kinase (ATP-L-glutamate 5-phosphotransferase) was purified about 85-fold from crude extracts of Pseudomonas aeruginosa strain PAO 1 by (NH4)2SO4 precipitation, molecular-sieving by Sephadex G-150 and DEAE-cellulose chromatography. The molecular weight of this enzyme was 84,000. The preparation catalysed formation of gamma-glutamyl hydroxamate from L-glutamate, ATP and Mg2+ or Mn2+ with concomitant hydrolysis of ATP to ADP + Pi. L-Proline inhibited the gamma-glutamyl kinase activity by 50% at 5 mM and almost completely at 30 mM. The inhibition of L-proline was non-competitive, wherease L-methionine-DL-sulphoximine inhibited the enzyme competitively. Proline was found to inhibit the gamma-glutamyl kinase activity of the wild-type strain and of representatives of two of the three transductional classes of proline-auxotrophic mutants. Strain PAO 879, a mutant representing the third transductional class of proline auxotrophs, lacked proline-inhibitible gamma-glutamyl kinase. Thiol-blocking reagents inhibited the gamma-glutamyl kinase and this effect was prevented by dithiothreitol.

Biosynthesis of proline in Pseudomonas aeruginosa. Properties of gamma-glutamyl phosphate reductase and 1-pyrroline-5-carboxylate reductase.

gamma-Glutamyl phosphate reductase, the second enzyme of proline biosynthesis, catalyses the formation of l-glutamic acid 5-semialdehyde from gamma-glutamyl phosphate with NAD(P)H as cofactor. It was purified 150-fold from crude extracts of Pseudomonas aeruginosa PAO 1 by DEAE-cellulose chromatography and hydroxyapatite adsorption chromatography. The partially purified preparation, when assayed in the reverse of the biosynthetic direction, utilized l-1-pyrroline-5-carboxylic acid as substrate and reduced NAD(P)(+). The apparent K(m) values were: NAD(+), 0.36mm; NADP(+), 0.31mm; l-1-pyrroline-5-carboxylic acid, 4mm with NADP(+) and 8mm with NAD(+); P(i), 28mm. 3-(Phosphonoacetylamido)-l-alanine, a structural analogue of gamma-glutamyl phosphate, inhibited this enzyme competitively (K(i)=7mm). 1-Pyrroline-5-carboxylate reductase (EC 1.5.1.2), the third enzyme of proline biosynthesis, was purified 56-fold by (NH(4))(2)SO(4) fractionation, Sephadex G-150 gel filtration and DEAE-cellulose chromatography. It reduced l-1-pyrroline-5-carboxylate with NAD(P)H as a cofactor to l-proline. NADH (K(m)=0.05mm) was a better substrate than NADPH (K(m)=0.02mm). The apparent K(m) values for l-1-pyrroline-5-carboxylate were 0.12mm with NADPH and 0.09mm with NADH. The 3-acetylpyridine analogue of NAD(+) at 2mm caused 95% inhibition of the enzyme, which was also inhibited by thio-NAD(P)(+), heavy-metal ions and thiol-blocking reagents. In cells of strain PAO 1 grown on a proline-medium the activity of gamma-glutamyl kinase and gamma-glutamyl phosphate reductase was about 40% lower than in cells grown on a glutamate medium. No repressive effect of proline on 1-pyrroline-5-carboxylate reductase was observed.

Polynucleotide phosphorylase has a role in growth of Escherichia coli.

Mutants having low levels of polynucleotide phosphorylase activity grow poorly at 45 C. All revertants isolated for their ability to grow better at that temperature also regained higher levels of polynucleotide phosphorylase and the ability to be induced for tryptophanase. Thus, a physiological role is implied for the enzyme polynculeotide phosphorylase.

Enzymic synthesis of N-acetyl-L-phenylalanine in Escherichia coli K12.

1. Cell-free extracts of Escherichia coli K12 catalyse the synthesis of N-acetyl-l-phenylalanine from acetyl-CoA and l-phenylalanine. 2. The acetyl-CoA-l-phenylalanine alpha-N-acetyltransferase was purified 160-fold from cell-free extracts. 3. The enzyme has a pH optimum of 8 and catalyses the acetylation of l-phenylalanine. Other l-amino acids such as histidine and alanine are acetylated at slower rates. 4. A transacylase was also purified from E. coli extracts and its substrate specificity studied. 5. The properties of both these enzymes were compared with those of other known amino acid acetyltransferases and transacylases.