Iodomethylated fatty acid metabolism in mice and dogs

The myocardial uptake of fatty acids labeled with radioactive iodine and injected i.v. can only be evaluated with SPECT if their oxidation kinetics is slow enough. For this reason, we evaluated different iodomethylated fatty acids in mice and dogs to determine which of them shows the highest myocardial uptake and the slowest oxidation. The most suitable was found to be 16-iodo-3-methyl hexadecanoic acid (mono ) since its myocardial fixation was the same as that of the reference, i.e. 16-iodo-9-hexadecenoic acid (IHA), whereas it was degraded more slowly. Thirty min after injection of mono into dogs, the decrease in myocardial activity with respect to the maximum was two fold less than after IHA injection. The myocardial uptake of the two dimethylated fatty acids studied, i.e. 16-iodo-2,2-methyl hexadecanoic acid and 16-iodo-3,3-methyl hexadecanoic acid, was less than that of IHA in mice and dogs. In the latter, the myocardial uptake was so small that we were unable to study the time course of its activity. Consequently, these dimethylated fatty acids are not suitable for the study of the myocardial uptake of fatty acids in man.     

Human Lyme arthritis and the immunoglobulin G antibody response to the 37-kilodalton arthritis-related protein of Borrelia burgdorferi

In Borrelia burgdorferi-infected C3H-scid mice, antiserum to a differentially expressed, 37-kDa spirochetal outer-surface protein, termed arthritis-related protein (Arp), has been shown to prevent or reduce the severity of arthritis. In this study, we determined the immunoglobulin G (IgG) antibody responses to this spirochetal protein in single serum samples from 124 antibiotic-treated human patients with early or late manifestations of Lyme disease and in serial serum samples from 20 historic, untreated patients who were followed longitudinally from early infection through the period of arthritis. These 20 patients were representative of the spectrum of the severity and duration of Lyme arthritis. Among the 124 antibiotic-treated patients, 53% with culture-proven erythema migrans (EM) had IgG responses to recombinant glutathione S-transferase (GST)-Arp, as did 59% of the patients with facial palsy and 68% of those with Lyme arthritis. In addition, 75 to 80% of the 20 past, untreated patients had reactivity with this protein when EM was present, during initial episodes of joint pain, or during the maximal period of arthritis. There was no association at any of these three time points between GST-Arp antibody levels and the severity of the maximal attack of arthritis or the total duration of arthritis. Thus, after the first several weeks of infection, 60 to 80% of patients had IgG antibody responses to GST-Arp, but this response did not correlate with the severity or duration of Lyme arthritis.     

Methylation of a euchromatin-heterochromatin transition region in Arabidopsis thaliana chromosome 5 left arm

Cytosine methylation was studied at the level of the euchromatin/heterochromatin transition genomic region of the Arabidopsis chromosome 5 left arm. It has been shown using a monoclonal antibody against 5-methylcytosines that the density of DNA methylation increases from the euchromatin towards the heterochromatin. YACs mapped along this region were characterized for their repeated sequences content. Some of them, corresponding to euchromatin, euchromatin/heterochromatin border and heterochromatin regions, were used as probes for a Southern blot analysis of methylation. This revealed that the degree of mCmCGG and GATmC methylation increases significantly from the euchromatin towards the heterochromatin. Moreover, an analysis of cytosine methylation levels (% of 5-methylcytosine) of different DNA fragments, inside the same genomic region, was performed using PCR and/or Southern blot approaches. There is a gradual increase of methylation along the genomic region analyzed: CpG methylation in the euchromatic fraction, CpG and CpNpG methylation at the euchromatin/heterochromatin transition and an additional asymmetrical methylation in the repeated-heterochromatic fraction. The most methylated repeated family at CpG, CpNpG and asymmetrical sites is the 5S ribosomal DNA, highly methylated even though it is transcribed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Biomarkers for toxicity and metabolic abnormalities of the main severe poisonings. Clinical and toxicologic symptoms. Conservative determination

The members of the joint group "Toxicology and Clinical Biology" of the French Society of Clinical Biology (SFBC), the French Society of Analytical Toxicology (SFTA), and the Society of Clinical Toxicology (STC), suggest guidelines to meet the requirements of clinical biologists who are not specialized in toxicology. Based on good laboratory practice they propose a number of guidelines. Three synthetic tables have been established. They are not only toxicity biomarkers and metabolic disorders associated with the main severe intoxications, but also clinical signs that are observed during these intoxications, finally biological sampling as a precautionary measure. The table also takes into account approximately fifty xenobiotics: main clinical signs emergency, identification or quantification of the suspected product, useful biological markers, therapeutic, quantitations necessary to take into consideration patient care, and poison antidotes, are described. Recommendations regarding medical and forensic techniques are also proposed by the group. It is also necessary to collect and store biological samples when the individual patients are in charge. These samples will be analyzed or not depending on the individual case history.     

Fertility in myotonic dystrophy in Saguenay-Lac-St-Jean: a historical perspective

Myotonic dystrophy (MD) is an autosomal dominant disorder that has a high prevalence in Saguenay-Lac-St-Jean. A case-control study, based on a population register, of 373 MD patients who married in this region between 1855 and 1971 was conducted to determine whether their fertility was affected by the disorder. Six demographic parameters, that is the number of children, the age at marriage, the ages at the time of birth of the first and the last child, the interval between the marriage and the birth of the first child, and the interval between consecutive births, were analyzed. The mean number of children born to MD and control individuals was not different (P > 0.05). However, MD males had more children than MD females although they have started delaying their marriage since 1921. Fertility fell significantly in both the MD and control groups during the period of observation. This change reflects the decline in fertility of French Canadians in general during this period, but mainly after 1940.     

Isolation, characterisation and preliminary cross-protection studies with a new pathogenic avian infectious bronchitis virus (Strain PL-84084)

Virological 1 examination of a severe infectious bronchitis (IB)-like field case in laying hens, led to the isolation of a coronavirus anti-genically different from Massachusetts, Connecticut and four Dutch IB variant strains. The virulence of the isolate for the fowl, and its dual tropism for the respiratory and genital tracts were demonstrated. In preliminary cross-protection studies Commercial vaccines did not protect against challenge with this isolate. These points and the possible economic significance of the virus are discussed.     

Dynamic CT features of hepatic abscesses

Forty hepatic abscesses were examined with dynamic computed tomography (CT). A "double target sign," consisting of a hypodense central area surrounded by first a hyperdense ring and then a hypodense zone, seems to be highly suggestive of abscess formation. In 12 cases, the hepatic parenchyma surrounding the lesion demonstrated transient hyperdensity after contrast injection, possibly due to localized hepatic venous obstruction secondary to acute hepatic inflammation. This is similar to the appearance of an arterioportal fistula.     

Recurrence of pulmonary embolism during anticoagulant treatment: a prospective study.

The risk of early recurrence of pulmonary embolism in patients with venous thromboembolic disease treated by anticoagulants is not well established. To determine the risk linked to contemporary proximal deep venous thrombosis, a prospective study was organised to give clinical and scintigraphic surveillance to 50 patients with angiographically proved pulmonary embolism plus phlebographically proved proximal deep vein thrombosis during the first 15 days of anticoagulant treatment. Perfusion lung scans were performed initially and on days 3, 7, and 15. Only two patients had a recurrence of pulmonary embolism during this period; both episodes were revealed by new symptoms, and one recurrence was fatal. The systematic performance of angiography in four patients found to have new scintigraphic defects led to the diagnosis of "spurious scintigraphic recurrence" in three of them. It is concluded that (a) adjusted anticoagulant treatment showed an effectiveness of 96% for preventing early recurrence of pulmonary embolism in this group of supposed high risk patients, and (b) in patients with recent pulmonary embolism new defects on systematic perfusion lung scans are not specific indicators of recurrent pulmonary embolism.