Enzymatically degraded low density lipoproteins are more potent inducers of egr-1 mRNA than oxidized or native low density lipoproteins

OBJECTIVES

The transcription factor early growth response gene-1 (Egr-1) may contribute to atherosclerosis by inducing genes that mediate inflammation and thrombosis. Egr-1 mRNA is highly expressed in human atherosclerotic lesions. Enzymatic modification transforms LDL into atherogenic molecules (E-LDL) which are also present in atherosclerotic lesions. We have investigated whether E-LDL induces egr-1 mRNA in human monocytes.

DESIGN AND METHODS

Mono-Mac-6 cells were incubated with E-LDL, oxidized (Ox-LDL) and native LDL (N-LDL). Egr-1 mRNA expression was followed by quantitative RT-PCR.

RESULTS

E-LDL (25 microg cholesterol/mL) induced egr-1 mRNA maximally within 1 h and were 2.3 and 3.6 fold (p < 0.05) more effective than Ox-LDL or N-LDL. At a concentration of 10 microg/mL cholesterol, E-LDL were twofold less effective.

CONCLUSIONS

These results show that E-LDL are potent inducers of egr-1 mRNA and may therefore represent a link between lipoproteins trapped in the subendothelium and enhanced expression of egr-1 in human atherosclerotic lesions.

A gravity-independent ergometer to be used for resistance training in space

An ergometer, to be used for resistance training in space, has been developed and validated. It is designed to activate the extensor muscles of the knee and ankle joints while performing the leg press exercise. Resistance is provided independent of gravity by using the inertial focus of a flywheel. Eleven men performed two series of consecutive maximal voluntary concentric and eccentric muscle actions. Force, power, work and electromyographic (EMG) activity, measured during exercise on this ergometer and a traditional leg press resistive apparatus were similar. This mechanical ergometer seems to meet the operational and technical requirements of equipment that can be flown and used in space. Also, the physiological responses to acute exercise suggest that adaptations similar to those achieved by traditional weight training can be produced. Exercise using the inertia ergometer would, therefore, probably also be effective in combating the muscle atrophy and loss of strength that occur in microgravity.

Cloning and sequencing of the fus-gene encoding elongation factor 2 in the archaebacterium Thermoplasma acidophilum

We have cloned a 1.6-kb region of chromosomal DNA from Thermoplasma acidophilum into Escherichia coli using as a probe part of the Methanococcus vannielii fus-gene. The sequence of the clone was highly homologous to part of the corresponding Methanococcus vannielii gene. By chromosome walking, a 4.7-kb EcoRI fragment containing the complete gene was isolated. Nucleotide sequencing revealed an open reading frame of 2196 nucleotides. The deduced amino acid sequence contains the known peptide sequence around the ADP-ribosylation site of T. acidophilum elongation factor 2, which unequivocally confirms that the fus-gene has been cloned. The amino acid sequence was compared to that of hamster and E. coli, as well as to known archaebacterial EF-2 sequences.

A novel eubacterial phylum: comparative nucleotide sequence analysis of a tuf-gene of Flexistipes sinusarabici

A tuf-gene of Flexistipes sinusarabici has been cloned and sequenced. The primary structure of the predicted elongation factor protein was compared with available sequences of homologous genes and elongation factors Tu or 1 alpha of eubacteria, archaebacteria and eukaryotes. Based on elongation factor Tu data Flexistipes sinusarabici belongs to the eubacterial kingdom but no specific relationship to any phylum was detected. The amino acid of the elongation factor Tu of F. sinusarabici exhibits no striking pecularities. Among the highly conserved positions only two are different. Sites of known or postulated functions are conserved.

Cloning and sequencing of the gene coding for the elongation factor 1 alpha from the archaebacterium Thermoplasma acidophilum

The gene which encodes the elongation factor 1 alpha (EF-1 alpha) of the archaebacterium Thermoplasma acidophilum (tuf-gene) has been cloned and sequenced. The gene coding for elongation factor EF-2 was found downstream from the 3' end of the tuf-gene. Comparison of the predicted amino acid sequence of Thermoplasma EF-1 alpha with EF-1 alpha sequences of other organisms showed that the highest similarity values were found between T. acidophilum and Methanococcus vannielii.

Prevention of supraventricular tachyarrhythmias post coronary artery bypass surgery

In a randomized prospective study 32 patients received either alinidine or a placebo for the first five postoperative days after coronary bypass surgery. The purpose of the study was to investigate the prophylactic antiarrhythmic properties of alinidine on supraventricular tachyarrhythmias (svt), which occur with incidence after open heart surgery. There was no significant difference in pretherapeutical parameters between the two groups. Eleven out of sixteen control patients (69%) and none of the patients treated with alinidine had svt. All arrhythmias occurred in the first three postoperative days and required medical treatment. Even after alinidine was stopped, patients in this group did not experience arrhythmias. The mean systolic blood pressure in the treatment group was 113 +/- 13 mmHg, in the control group it was 119 +/- 16 mmHg. The mean heart rate tended to be lower in the alinidine group (82 +/- 12 beats min-1 91 +/- 21 beats min-1. In 1/16 patients the alinidine treatment was stopped due to marked hypotension (less than 90 mmHg) and bradycardia (less than beats min-1). Two other patients in this group had short periods of mild bradycardia (less than 60 beats min-1) which was tolerated well. Additional medical treatment was not needed. In this study prophylactic treatment with alinidine proved to be highly effective in preventing postoperative arrhythmias following myocardial revascularisation.