Cross-linking of proteins by Maillard processes: characterization and detection of lysine-arginine cross-links derived from glyoxal and methylglyoxal.

Alpha-dicarbonyl compounds, such as glyoxal and methylglyoxal, are crucial intermediates in the browning and cross-linking of proteins by reducing sugars in the course of the Maillard reaction. The cross-linking units 2-ammonio-6-([2-[(4-ammonio-5-oxido-5-oxopentyl)amino]-4,5-dihydro - 1H-imidazol-5-ylidene]amino)hexanoate (9) and 2-ammonio-6-([2-[(4-ammonio-5-oxido-5-oxopentyl) amino]-4-methyl-4,5-dihydro-1H-imidazol-5-ylidene]amino)hexanoate (10), designated as GODIC and MODIC, are identified and quantified from glyoxal/methylglyoxal-bovine serum albumin (BSA) incubations. Independent syntheses and unequivocal structural characterization are given for 9 and 10. A protocol was established for their determination by liquid chromatography-mass spectrometry (LC-MS) with electrospray ionization (ESI). BSA and the respective alpha-dicarbonyl compound were incubated at 37 degrees C, pH 7.4 for 1 week, and the time-dependent formation of 9 and 10 was observed. The maximum value obtained from a solution containing 50 g/L BSA and 2 mM glyoxal or methylglyoxal after a 7-day incubation period corresponds to an arginine derivatization quota of 13.0 +/- 0.32 mmol 9/mol Arg or 3.0 +/- 0.12 mmol 10/mol Arg. The cross-links 9 and 10 were also detected in a D-glucose-BSA incubation. From these results, it seems justified to assign an important role to 9 and 10 in the cross-linking of proteins in vivo as well as in foodstuffs. In an additional model study, formation of 9 and 10 was compared to that of the imidazolium cross-links GOLD 3 and MOLD 4.

[Spondylogenic cervical myelopathy: conservative and surgical therapy]. / Die spondylogene zervikale Myelopathie: konservative und operative Therapie.

The symptoms and signs of spondylotic cervical myelopathy (SCM) in the elderly are variable, but an ataxic-spastic gait disturbance combined with tingling in the finger tips and clumsy hands are often encountered. SCM is due to degenerative changes of discs and osseous and ligamentous structures with compression of the spinal cord. The symptoms, signs, surgical and conservative treatment, and outcome were retrospectively analyzed in 36 patients. Most of the patients undergoing surgery (n = 22) improved their clinical score and maintained this improvement for the period of observation; the non-operated patients (n = 14) had a very slow progression. Diagnostic difficulties and problems of the surgical and conservative approaches are discussed.

Anterior microsurgical approach for degenerative cervical disc disease.

One hundred-ninety-six patients with spinal cord or nerve root compression were operated on by anterior microsurgical discectomy without graft between 1978 and 1987. The patients presented either with spinal cord compression (33%) or radicular symptoms with a duration of 12 days to more than then years (66%). Investigations to confirm these clinical syndromes employed myelography, CT or MRI. Two-hundred-eighty-eight levels were explored; 124 one level, 54 two level, 17 three level and 2 four level operations were done. The follow-up (mean 6.7 years) showed 66% of the patients with excellent or good results after two years. The low risks of anterior discectomy were further diminished with skillful microsurgical technique without intercorporeal fusion. A comparison of our results at follow-up with published series, in which the anterior approach was used but with intervertebral autologous bone graft after disc removal, shows no significant differences. We therefore recommend the anterior microsurgical discectomy without fusion as the treatment of choice.

The diagnosis of solitary primary reticulum cell sarcoma of the posterior fossa with computed tomography.

The CT findings in two surgically and histologically verified cases of primary reticulum cell sarcoma of the cerebellar hemisphere with secondary involvement of the cerebellopontine angle are presented. It is suggested that a correct diagnosis is possible by CT if the following criteria are present: 1. slightly increased attenuation of the mass on the precontrast scan; 2. mottled appearance of the definitely enhancing mass; 3. ill-defined borders on both the pre- and postcontrast scans; 4. degree of mass effect less than that expected from the size of the lesion; 5. involvement of the cerebellopontine angle without signs indicating an extra-axial origin of the tumor. These criteria reflect the gross and microscopic neuropathological features of the tumor.

Gene expression of herpes simplex virus. II. UV radiological analysis of viral transcription units.

The transcriptional organization of the genome of herpes simplex virus type 1 was analyzed by measuring the sensitivity of viral polypeptide synthesis to UV irradiation of the infecting virus. Herpes simplex virus type 1 was irradiated with various doses of UV light and used to infect xeroderma pigmentosum fibroblasts. Immediate early transcription units were analyzed by having cycloheximide present throughout the period of infection, removing the drug at 8 h postinfection, and pulse-labeling proteins with [35S]methionine. Delayed early transcription units were analyzed in similar studies by having 9-beta-D-arabinofuranosyladenine present during the experiment to block replication of the input irradiated genome. The viral polypeptides were separated by gel electrophoresis and quantitated by densitometry of the gel autoradiograms. The following results were obtained. (i) The UV target sizes for the viral transcription units analyzed ranged from 1.44 to 5.65 kilobase pairs. This implies that the corresponding primary transcripts have minimum molecular weights ranging from 0.46 x 10(6). (ii) The genes for the four viral proteins, 165, 145, 116, and 71 (molecular weight x 10(3), exhibited UV target sizes that agree with their calculated gene size or measured mRNA size or both and thus must reside in promoter-adjacent positions. (iii) The transcription units for the remaining genes analyzed showed target sizes that range from 0.42 to 2.59 kilobase pairs greater than needed to encode the respective proteins. This probably is a reflection of their distances from promoters or the presence of intervening sequences or both. It further suggests that these genes are transcribed as precursor RNA molecules that are larger than their mRNA's. (iv) The results indicate that none of the immediate early genes analyzed can be cotranscribed, whereas some of the delayed early genes might be cotranscribed. No evidence was found for the existance of large, multigene transcription units.

A clinical and experimental study of meglumine iocarmate in the subarachnoid space: a complication of positive contrast ventriculography.

Meglumine iocarmate (Dimer-X) may be accidentally put into the subarachnoid space because of suboptimal technique during ventriculography. This may cause status epilepticus. Two cases of this complication are reported. It is emphasized that this should be avoided. Treatment is mentioned briefly.