[Intoxication from accidental ingestion of cannabis: analysis of eight cases]. / À propos de 8 cas d'intoxication accidentelle au cannabis chez des nourrissons.

Consultations at pediatric emergency units for acute consciousness alterations is frequent. Miscellaneous causes include cranial trauma, meningoencephalitis, metabolic disorders, drugs, or other intoxications. We report here eight cases of infants who were brought to the emergency division due to acute consciousness failure after accidental ingestion of hashish, confirmed by urinary dosage of Δ9-tetrahydrocannabinol. This series of under 24-month-old infants only emphasizes the value of screening for cannabis in urine in cases of abnormal consciousness and/or abnormal behavior in an infant.

[A 2-month-old baby with Mediterranean spotted fever]. / Une fièvre boutonneuse méditerranéenne chez un nourrisson de 2 mois.

INTRODUCTION: Mediterranean spotted fever is an endemic rickettsiosis in southern France. We report here the case of a 2-month-old baby who developed rickettsiosis after a tick bite. CLINICAL FACT: A 2-month-old baby was hospitalized in the pediatric ward for fever with maculopapular rash extending to the palms and plantar surfaces and an eschar after a tick bite. Rickettsiosis serology examined after 48 h of fever was negative, but Rickettsia (spotted group) PCR taken from the lesion at the bite site was positive. A 1-week treatment with clarithromycin was started. Fever and rash disappeared 3 days after treatment initiation. DISCUSSION: Mediterranean spotted fever is endemic in southern France. It is, therefore, important to consider this diagnosis and search for tick bite signs or an eschar when a patient presents with fever and maculopapular rash. The treatment of choice consists in doxycycline or macrolides. CONCLUSION: Around the Mediterranean sea in particular, Mediterranean spotted fever should be considered as a possible cause of febrile disease with rash, to allow for a specific antibiotic treatment as fast as possible and to avoid dangerous complications, even though few cases have been reported below the age of 3 months.

Identification of a human epitope in hepatitis C virus (HCV) core protein using a molecularly cloned antibody repertoire from a non-symptomatic, anti-HCV-positive patient.

Healthy carriers of hepatitis C virus (HCV) infection exhibit a specific antibody response against all HCV antigens, which could play a role in disease control. Generation of panels of human antibodies may permit a thorough characterization of this response and further identify particular antibodies with potential clinical value. To this effect, we have established a human phage-display antibody library from a patient exhibiting a high antibody response against HCV antigens and no clinical symptoms of disease. This library was screened against a recombinant core antigen [amino acids (aa) 1-119] produced in E. coli. Two recombinant Fab-carrying phages (rFabCs) were isolated and characterized. Both rFabC3 and rFabC14 recognize aa 1-48 on core antigen, but rFabC14 is competed out by a synthetic peptide, C(2-20) (aa 1-20), at much lower concentrations than rFabC3. In order to identify more precisely the recognition sites of these antibodies, we produced soluble forms of the rFabs (sFabs), and used them to pan a random phage-display peptide library. A single peptide sequence, QLITKPL, was identified with sFabC3, while two equally represented sequences, HAFPHLH and SAPSSKN, were isolated using sFabC14. The QLITKPL sequence was partially localized between aa 8 and 14 of core protein, but no clear homology was found for the two sFabC14 peptides. However, we confirmed the specificity of these peptides by competition experiments with sFabC14.

Purification and characterization of an alpha-L-arabinofuranosidase from Streptomyces lividans 66 and DNA sequence of the gene (abfA).

The gene encoding an alpha-L-arabinofuranosidase (abfA) was homologously cloned in Streptomyces lividans and its DNA sequence was determined. The enzyme was purified from the cytoplasm of the hyperproducing clone S. lividans IAF116. Its M(r) was estimated by gel filtration and found to be approx. 380,000. Since SDS/PAGE indicated a native protein of M(r) 69,000, it can be concluded that the native protein consists of several subunits of that size. The pI value was 4.6. The kinetic constants determined with p-nitrophenyl alpha-L-arabinofuranoside as substrate were a Vmax of 180 units/mg of protein and a Km of 0.6 mM. The specific activity of the purified enzyme on this substrate was 153 units/mg of protein. Optimal enzyme activity was obtained at 60 degrees C and pH 6.0. The enzyme cleaved p-nitrophenyl alpha-L-arabinofuranoside, but had no activity on a variety of other p-nitrophenyl glycosides, except on p-nitrophenyl beta-D-xylopyranoside. The enzyme showed no activity on oat-spelts (Avena sativa) xylan or arabinogalactan, but acted on beet (Beta) arabinan or arabinoxylan. Hydrolysis occurred on arabino-oligoxylosides obtained from oat-splets xylan after digestion with xylanases. Since S. lividans normally does not secrete arabinofuranosidase, this enzyme may play a role in the assimilation of arabinose moieties from arabinose-containing xylo-oligosaccharides generated by beta-xylosidases or xylanases.

Identification of two acidic residues involved in the catalysis of xylanase A from Streptomyces lividans.

On the basis of similarities between known xylanase sequences of the F family, three invariant acidic residues of xylanase A from Streptomyces lividans were investigated. Site-directed-mutagenesis experiments were carried out in Escherichia coli after engineering the xylanase A gene to allow its expression. Replacement of Glu-128 or Glu-236 by their isosteric form (Gln) completely abolished enzyme activity with xylan and p-nitrophenyl beta-D-cellobioside, indicating that the two substrates are hydrolysed at the same site. These two amino acids probably represent the catalytic residues. Immunological studies, which showed that the two mutants retained the same epitopes, indicate that the lack of activity is the result of the mutation rather than misfolding of the protein. Mutation D124E did not affect the kinetic parameters with xylan as substrate, but D124N reduced the Km 16-fold and the Vmax. 14-fold when compared with the wild-type enzyme. The mutations had a more pronounced effect with p-nitrophenyl beta-D-cellobioside as the substrate. Mutation D124E increased the Km and decreased the Vmax. 5-fold each, while D124N reduced the Km 4.5-fold and the Vmax. 75-fold. The mutations had no effect on the cleavage mode of xylopentaose.

Flow cytometry studies of recombinant Escherichia coli in batch and continuous cultures: DNA and RNA contents; light-scatter parameters.

Flow cytometry has been used to study the contents of macromolecular compounds and light-scatter parameters in batch and continuous cultures of a recombinant Escherichia coli strain that forms protein inclusion bodies. Changes in relative DNA and RNA contents and cell mass as estimated by forward-angle light scatter were detected and tightly correlated in batch culture. In addition, heterogeneity of wide-angle light scatter (WALS), which we related to the presence of cellular inclusion bodies, was observed. In contrast, the relative RNA content and cell mass did not change during continuous culture, and homogeneity of WALS was found. In addition, unexpected changes in relative DNA content were observed after 67 h of culture, indicating a change in bacterial physiology.