Biomedical subjects
Publications and source records attributed to C Carlier.
Shoulder dislocation is a frequent pathology with a high level of recurrences especially in young patients. One week immobilization in a Dessault dressing is sufficient if it is followed by free mobilization avoiding external rotation and abduction. A 6 weeks rehabilitation program seems to prevent recurrences.
The sat4 streptothricin resistance gene from Campylobacter coli BE/G4 was cloned into pUC18, and its nucleotide sequence was determined. Streptothricin acetyltransferase activity was detected in Escherichia coli cells containing recombinant plasmid pAT132 which carries the sat4 gene as an insert. The deduced amino acid sequence displayed 21-27% amino acid identity with streptothricin acetyltransferases from E. coli and streptothricin producers Streptomyces lavendulae and Streptomyces noursei. The sat4 gene was detected by hybridization in clinical and environmental isolates of Campylobacter spp.
OBJECTIVES: To determine whether beta carotene is therapeutically equivalent to retinyl palmitate in the formulation currently recommended by the World Health Organisation. DESIGN: Randomised blind equivalence trial. SETTING: Rural area in Senegal. SUBJECTS: Children aged 2-15 years suffering from vitamin A deficiency as defined by abnormal results on eye cytology were randomly allocated treatment with retinyl palmitate (n = 256) and beta carotene (n = 254). MAIN OUTCOME MEASURE: Reversion to normal results on eye cytology as defined by the reappearance of goblet cells and normalisation of the epithelial cells. RESULTS: Seven weeks after the supplement was given the percentages were 51.2% (124/242) children taking retinyl palmitate and 50.0% (123/246) of those taking beta carotene, who had reverted to normal eye cytology, a difference of 1.2% (95% confidence interval 6.2% to 8.6%) [corrected]. According to an equivalence testing procedure, the two treatments were statistically equivalent; the null hypothesis of non-equivalence was rejected (one tailed p value = 0.03). CONCLUSIONS: beta Carotene supplementation seems to be a promising candidate for the alleviation of vitamin A deficiency. It could be given either as high dose capsule or through increased dietary intake. The challenge now is to improve dietary intake of vitamin A in programmes that are effective and sustainable at the community level.
Excision and integration of Tn1545 occur by reciprocal site-specific recombination between 6 (or 7) bp variable sequences present in the recombining attachment (att) sites and designated overlap regions. We devised an assay for Tn1545 transposition in which derivatives containing the cis-acting transposition sequences (attTn 1545) integrate into a target replicon when complemented in trans by the transposon-encoded integrase Int-Tn. This assay was used to determine the characteristics of the DNA sequence that influence target site selection. Characterization of several integration sites indicated that a 20 bp segment, designated attB, contains the sequences required for target activity. It also appeared that (i) the target activity depends upon the extent of homology between the 7bp segments flanking the overlap regions in attB and attTn 1545, and (ii) the degree of homology between the two recombining overlap regions does not affect the level of target activity and has no influence on integration orientation.
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The historical background to angioscopy shows that the principal successes recorded by its use result from the miniaturization of fibroscopes and the progress in video imaging. The first tentative use of angioscopy was by surgeons during operations carried out at about 1970, that of percutaneous angioscopy dating from 1984. The material used for diagnostic (fibroscope, cinecamera, video system, flushing pump) and interventional (fibroscope, clamps, Dormia cage, endoprostheses ... ) angioscopy is such that the basic equipment requires an outlay of about 150 to 200,000 francs. Percutaneous angioscopy implies the insertion of a catheter allowing flushing of the arterial lumen by means of a pressurized perfusion pump which, when reversed, is transformed into an aspirating pump for removal of the clot and/or atheromatous debris. The procedure is simple and does not expose to more complications than conventional arteriography.
Efficacy of percutaneous treatments of arterial affections requires the correct choice of indications, necessitating precise knowledge of elementary arterial lesions. Arterial endoscopy appears to be more specific than angiography for this use, since it allows direct vision in vivo of the lesion, a histopathologic approach compared with the non univocal images produced by angiography (for example, an arterial obstruction can result from varied causes). Different accidents to the endothelial surface can be observed: golden yellow atheromatous elevations on a straw yellow background, intimal flaps, mobile intra-luminal vegetations. Established atheromatous stenosis are smooth and regular, or on the contrary ulcerated and edged with irregular flaps capable of provoking an eccentric residual lumen. The vegetating atheromatous lesions may project into the lumen, often as calcified and thus pearly white scales adhering to the wall, or as larger occlusive lesions. When capable of being isolated, a thrombus often completes the stenosis: its recognition is therefore fundamental since its removal exposes the subjacent lesions to be treated. The fresh clot is coral shaped, bright red and mobile in the blood flow. Established clots are compact and greenish brown. At an advanced stage of atheroma the surface of the occluding clot is covered with a regular straw yellow endothelium. In the presence of a dissecting vessel the fibroscope may be introduced into the false channel, no longer showing typical endothelium but a coagulated mass interspersed with fibrous bands. Prosthetic stenosis result from either intimal hyperplasia or a suturing fault with plication.
Since 1987, routine angioscopic examination has been performed in 191 patients undergoing angioplasty, with interventions (196) after a 2 year surveillance period (55). Angioscopy allowed follow up "de visu" of the performance of angioplasty, details of its mechanism to be precise and under dilatation to be carried out. For femoral artery occlusions it allowed treatment "à la carte": conventional dilatation of vegetating atheroma, specific treatment of established thrombi (5) and abstention from therapy of atheroma covered by endothelium (3). It also enabled fresh thrombi complicating a stenosis or at the origin of a thrombus to be detected. The extraction technique employed (15) is described. It facilitated catheterization by directing the probe, enabled avoidance of bypassing of stenosis and flaps and of dissection or false introduction into collaterals (10). Directed biopsy could be carried out in inflammatory arteritis (7). Vegetating atheromatous lesions could be opened and extracted, facilitating subsequent dilatation and allowing an approach to removal of iliac artery obstructions without major risks of complications (13). Finally, after an ineffective dilatation or the presence of a dissection, it assisted making the decision to introduce a stent (9), the tolerance and outcome of these stents are described. Or the 196 patients considered suitable for angioplasty, our therapeutic conduct was modified by angioscopy in 58 cases (29%). Not simply a new diagnostic tool, it plays a role in interventional vascular techniques.
Administration of large oral doses of retinyl palmitate has become the most widely practised vitamin A deficiency prevention strategy in developing countries. We conducted a follow-up study among 220 Senegalese children aged 2-7 years suffering from moderate undernutrition to determine the efficacy of vitamin A treatment on their vitamin A status assessed by biochemical and cytological (impression cytology with transfer) methods. The first examination (T = 0 m[onth]) was carried out during April 1989, before the mango (Mangifera indica L,) harvest. The second examination (T = 2 m) was carried out 2 months after vitamin A treatment during June 1989 when ripe mangoes become widely available. Conjunctival cells of the eyes of the children with or without ocular inflammation were responsive to vitamin A administration (P < 0.01). There was a significant increase (P < 0.001) in mean serum retinol and beta-carotene levels between T = 0 m and T = 2 m. Mean serum retinol-binding protein (RBP) and transthyretin (TTR) levels did not differ significantly (P > 0.05) at T = 0 m and T = 2 m. Despite the intake of vitamin A, 54% of the children who had abnormal cytology at T = 0 m remained abnormal at T = 2 m. This was due to inadequate levels of TTR and RBP, presumably due to the cereal diet eaten by the Senegalese population. children with abnormal eye cytology had lower serum retinol levels than those with normal eyes at T = 0 m, and beta-carotene values did not correlate with eye cytological abnormalities at T = 0 m. Children with normal cytology had higher serum retinol and also beta-carotene levels than those with abnormal cytology after massive oral doses of vitamin A and consumption of mangoes at T = 2 m. Retinyl palmitate may, therefore, only lead to partial cytological improvement due to a lack of retinol-carrier proteins but dietary beta-carotene may also be involved.
The increasing importance of vitamin A deficiency in even its mild subclinical form underlines the need for a mass screening test. Clinical, biochemical and cytological methods of assessing vitamin A deficiency in a public health setting have been described and widely used. The cytological method shows promise because it enables early detection of vitamin A deficiency. However interpretation is problematic since histopathological changes are gradual with the progressive disappearance of goblet cells and appearance of enlarged epithelial cells. The reliability and validity of the impression cytology with transfer (ICT) test were assessed in order to produce a meaningful standard for this cytological method. The ICT test was performed in Senegal on 1451 children, in the course of two surveys conducted in 1989 and 1990 in rural areas. Reliability, estimated by Cohen's kappa test for evaluating intra-reader variability, and sensitivity were highest for the abnormal-normal classification (kappa = 0.91; 95% confidence interval (CI): 0.89-0.93; and sensitivity = 74%; 95% CI 66-82%). The ICT method is a cheap, noninvasive and easy test to perform in the field. This method is also reproducible and fairly sensitive according to the abnormal-normal classification. As illustrated by our proposed 50% cutoff of abnormal cytology calculated in relation to 5% of serum retinol values below 0.35 mumol/L criterion, ICT only requires a small sample for the assessment of the overall health of a community in contrast to xerophthalmia and blood vitamin A deficiency tests.
The genetic basis of tetracycline resistance was studied in 25 clinical isolates of Listeria monocytogenes. Resistance to tetracycline was associated with resistance to minocycline and due to the presence of the tet(M) gene in 24 strains. Association of tet(M) with int-Tn, the gene encoding the protein required for the movements of Tn1545-like conjugative transposons, was found in all strains. Cotransfer of tet(M) and int-Tn among L. monocytogenes cells and from L. monocytogenes to Enterococcus faecalis was detected in 7 of the 12 strains studied at frequencies similar to those obtained with the prototype element Tn1545. tet(L), the second most prevalent tetracycline resistance gene in enterococci and streptococci, was detected in the remaining strain, where it was borne by a 5-kb plasmid. These observations indicate that two types of movable genetic elements, transposons and plasmids, in enterococci and streptococci are responsible for emergence of drug resistance in L. monocytogenes.
The increasing concern about vitamin A deficiency in even its mild subclinical form has created the need for a mass screening test. Various clinical, biochemical and cytological methods for assessing the vitamin A status have been widely used but all are unsatisfactory for technical, ethical or public health reasons. The two prevalence criteria defined by the World Health Organization (WHO) for a vitamin A deficiency problem of public health significance are xerophthalmia and serum retinol concentrations. Recently we proposed a prevalence criterion for impression cytology with transfer (ICT) at the level of 50% of ICT results being abnormal. We conducted a cross-sectional survey of the prevalence of vitamin A deficiency and also undernutrition during the dry season in a random sample of 1,259 children (n = 442 for the 2-6 years and n = 817 for the 7-14 years) from a rural area in Senegal. Prevalence was 0 times and 4.2 times the WHO criteria for xerophthalmia and deficient serum retinol levels, respectively in preschool children. Abnormal ICT results were more frequent in preschool than in school children (53.4% versus 21.0%). There was an association between abnormal ICT results and stunting. Vitamin A deficiency was a public health problem in preschool children as assessed by the biochemical criterion (20.9% of serum retinol values under 0.35 mumol/l) or the cytological cut-off (53.4% of abnormal ICT results) but was also found in school children (21.0% of abnormal ICT results).
The changes in the vitamin A and nutritional status of children from a rural area in Senegal were determined by the same team during two cross-sectional surveys distant from exactly one year. At baseline (T = 0 year) 1,259 children were chosen at random. One year later (T = 1 year), 1,008 children were re-examined. Vitamin A and nutritional status were assessed by clinical and cytological methods, and by anthropometrical indicators for the 1,008 participants, respectively. No signs of xerophthalmia were recorded at T = 0 and T = 1 year. The proportions of children deficient in vitamin A as defined by abnormal cytology and suffering from stunting were similar at these two measuring points. Even though these percentages remained similar at T = 0 and T = 1 year, there existed little movement between the abnormal and normal eye cytology group and the stunted and non-stunted group. Since vitamin A is required for normal growth, we calculated the mean linear gain in height according to the eye cytological changes assessed between the two examinations. We found that mean linear growth increments were higher in the groups of children who remained abnormal or reverted to abnormal cytology than in those who remained normal or reverted to normal cytology.
In a countrywide survey, we assessed the prevalence of vitamin A deficiency by clinical examination and impression cytology with transfer method (ICT) in a randomized sample of 2445 subjects representative of the population of the Republic of Djibouti. A plasma retinol determination was made on a part of this sample. Results lead to believe that serious vitamin A deficiency may periodically occur in Republic of Djibouti when nutritional conditions become poor. Meanwhile a large number of children, mostly in the rural area, have a marginal vitamin A status and are exposed to a high level of risk.
We have constructed and used an integrative vector, pAT112, that takes advantage of the transposition properties (integration and excision) of transposon Tn1545. This 4.9-kb plasmid is composed of: (i) the replication origin of pACYC184; (ii) the attachment site (att) of Tn1545; (iii) erythromycin-and kanamycin-resistance-encoding genes for selection in Gram- and Gram+ bacteria; and (iv) the transfer origin of IncP plasmid RK2, which allows mobilization of the vector from Escherichia coli to various Gram+ recipients. Integration of pAT112 requires the presence of the transposon-encoded integrase, Int-Tn, in the new host. This vector retains the insertion specificity of the parental element Tn1545 and utilises it to carry out insertional mutagenesis, as evaluated in Enterococcus faecalis. Since pAT112 contains the pACYC184 replicon and lacks most of the restriction sites that are commonly used for molecular cloning, a gene from a Gram+ bacterium disrupted with this vector can be recovered in E. coli by cleavage of genomic DNA, intramolecular ligation and transformation. Regeneration of the gene, by excision of pAT112, can be obtained in an E. coli strain expressing the excisionase and integrase of Tn1545. The functionality of this system was illustrated by characterization of an IS30-like structure in the chromosome of En. faecalis. Derivatives pAT113 and pAT114 contain ten unique cloning sites that allow screening of recombinants having DNA inserts by alpha-complementation in E. coli carrying the delta M15 deletion of lacZ alpha. These vectors are useful to clone and introduce foreign genes into the genomes of Gram+ bacteria.
The mobilizable shuttle cloning vectors, pAT18 and pAT19, are composed of: (i) the replication origins of pUC and of the broad-host-range enterococcal plasmid pAM beta 1; (ii) an erythromycin-resistance-encoding gene expressed in Gram- and Gram+ bacteria; (iii) the transfer origin of the IncP plasmid RK2; and (iv) the multiple cloning site and the lacZ alpha reporter gene of pUC18 (pAT18) and pUC19 (pAT19). These 6.6-kb plasmids contain ten unique cloning sites that allow screening of derivatives containing DNA inserts by alpha-complementation in Escherichia coli carrying the lacZ delta M15 deletion, and can be efficiently mobilized by self-transferable IncP plasmids co-resident in the E. coli donors. Plasmids pAT18, pAT19 and recombinant derivatives have been successfully transferred by conjugation from E. coli to Bacillus subtilis, Bacillus thuringiensis, Listeria monocytogenes, Enterococcus faecalis, Lactococcus lactis, and Staphylococcus aureus at frequencies ranging from 10(-6) to 10(-9). The presence of a restriction system in the recipient dramatically affects (by three orders of magnitude) the efficiency of conjugal transfer of these vectors from E. coli to Gram+ bacteria.
The evaluation of the prevalence of ophthalmological diseases and vitamin A deficiency in Senegalese preschool-aged children enabled us to confirm the method of impression cytology with transfer (ICT) and to assess the impact of ophthalmological diseases on the cytological appearance of conjunctival cells. A simplification of the ICT method consisted of transferring cells present on a strip of paper to a glass slide by finger pressure. Harris-Schorr staining of the sample papers confirmed the results obtained by the transfer. Inflammatory trachoma influenced the results of the test. This simple method will prove very helpful for detection of vitamin A deficiency in children in underdeveloped areas.
The purpose of our study was to determine the prevalence of protein-calorie malnutrition (PCM), ocular diseases, and vitamin A deficiency in preschool children selected at random in a rural zone of the groundnut belt of Senegal. The prevalence of PCM was 37.1% (95% CI 33.8-40.2%) according to the Waterlow classification, with a majority of stunting, and prevalence of hypovitaminosis A was estimated to be 11.4% (95% CI 9.3-13.5%) by using impression cytology. Furthermore, 19.4% (95% CI 15.8-22.0%) of the children might be defined at risk of deficiency. The prevalence of Bitot's spots was equal to 0.2% (95% CI 0.03-0.9%). A problem of PCM associated with a health-endangering vitamin A deficiency existed.