Association of palliative care management and survival after chemotherapy discontinuation in patients with advanced pancreatic adenocarcinoma: A retrospective single-centre observational study

BACKGROUND

Palliative care (PC) is integrated into standard oncology care. However, its clinical impact at the end of life remains unclear in pancreatic adenocarcinoma (PA). We aimed to describe the end-of-life care pathway and to assess whether PC referral influences survival after chemotherapy discontinuation (CD) among advanced PA patients.

METHODS

This retrospective single-centre observational study was conducted among deceased patients with advanced PA who had received chemotherapy between January 1, 2016, and December 31, 2021. Baseline characteristics, the timing of PC referral and events after CD were collected. The primary outcome was time from CD to death.

RESULTS

Among the 148 included patients, 53.4% (n = 79) received PC, mostly late after the CD (n = 133, 89.9%), 16.9% (n = 25) received chemotherapy in the last 14 days of life and 75.6% died at the hospital. None received PC in the 8 weeks following the diagnosis. PC referral significantly increased PC department admissions (p < 0.001) and decreased medical unit admissions (p < 0.001). The median survival after the CD was 35 days (IQR: 19-64.5). PC referral was associated with increased survival after CD (HR: 0.65 [0.47-0.90], p = 0.010, Cox) and after adjusting (HR: 0.65 [0.42-0.99], p = 0.045, Cox).

CONCLUSION

The study suggests that PC may be associated with longer survival after CD in advanced PA patients. However, PC is underused, and patients are referred late in their care pathway.

[Efficacy and safety of tranexamic acid administration for the prevention and/or the treatment of post-partum haemorrhage: a systematic review with meta-analysis]

OBJECTIVE(S)

Assess the efficacy and safety of tranexamic acid administration for the prevention and/or the treatment of postpartum haemorrhage.

STUDY DESIGN

Systematic review with meta-analysis.

MATERIAL AND METHODS

Systematic review of the literature with the aim of identifying prospective, randomised, controlled trials that assessed the effect of tranexamic acid on peripartum blood loss and transfusion requirement in three clinical contexts: (i) prevention of post-partum haemorrhage in case of elective caesarean section, (ii) prevention of post-partum haemorrhage in case of vaginal delivery, (iii) treatment of post-partum haemorrhage.

RESULTS

Prophylactic administration of tranexamic acid reduced blood loss (mean difference for intraoperative blood loss: -177.9mL, IC 95%: -189.51 to -166.35, total blood loss: -183.94, IC 95%: -198.29 to -169.60), and the incidence of severe post-partum haemorrhage (OR: 0.49, IC 95%: 0.33 to 0.74). None of the published trials assessed the effect of tranexamic acid on blood products administration or transfusion requirement. Only one study assessed and reported the efficacy of tranexamic acid when administered as a treatment for postpartum haemorrhage. A significant reduction in blood loss was reported within 30 minutes after randomisation (P=0.03) and confirmed after 6 hours (median: 170mL (58-323) vs 221mL (110-543), P=0.04). None of the included studies adequately studied the incidence of side effects after tranexamic acid administration.

CONCLUSION

Although tranexamic acid administration seemed to significantly reduce blood loss and the incidence of severe post-partum haemorrhage, further prospective trials are needed to confirm the efficacy and safety of tranexamic administration in the treatment of postpartum haemorrhage. Those studies should assess the pharmacokinetic profile and the safety of this drug in pregnant women.

[Relationship between benzodiazepines use and falls in the elderly: a multicenter study in three geriatric centers of a university hospital]

INTRODUCTION

Benzodiazepines are widely used in the elderly, but may induce potentially severe iatrogenic events like falls. The analysis of their use is difficult because of the numerous molecules and dosages available. The aim of the present study is to build a tool to monitor their consumption and to evaluate the relation between this consumption and patient's falls reported in three geriatric institutions.

METHODS

Conversion coefficients found in the literature allowed the expression of benzodiazepine action with a unique comparator: diazepam. Benzodiazepine consumption observed during 20 consecutive months was collected and weighted by hospital activity. A correlation between benzodiazepine consumption and the number of falls reported during the same period was researched.

RESULTS

Benzodiazepine consumption expressed in milligrams of diazepam-equivalent per hospitalization day is significantly linked to the number of falls expressed during the same period (R=0.63; p<0.01). However, no statistical bound was found between monthly falls variations and monthly benzodiazepine consumption variations. These results corroborate others published studies: benzodiazepine consumptions are statistically linked to falls, but the reduction of this consumption is of poor predictive value, maybe because of the multifactorial nature of falls.

DISCUSSION AND CONCLUSION

The expression of benzodiazepine consumption in diazepam-equivalent enables one to estimate the general exposition of patients and to compare the use of each molecule. The statistical link between this indicator and a major iatrogenic event like falls makes it a tool worth interest for both clinicians and pharmacists.

[Inborn errors of metabolism: new developments and challenges]

The concept "inborn error of metabolism" (IEM) arose from the observations of Sir A. Garrod at the beginning of the XXth century. The exponential development, during the last decades, of our knowledge in cellular biology and molecular genetics, and the availability of increasingly more precise diagnostic tools, allow the identification of a still growing number of inborn errors of metabolism. Their physiopathology is better understood. Treatments have considerably improved: more specific diets, new medical treatments, enzyme replacement therapy, organ transplantation, hepatocyte or stem cell transplantation... New techniques are under development, including various strategies of gene therapy. Improved therapeutic efficacy combined with earlier diagnosis have dramatically changed the prognosis of many disorders. As a consequence, new challenging questions have to be answered. Today, patients with an IEM, because of the extreme complexity of their management, need to be looked after by a multidisciplinary team of physicians (pediatricians and internists), dieticians, social workers, psychologists... It is essential, in this complex and rapidly expanding field, that experiences should be shared at national and international level, in order to provide the most adequate care for patients.

Is coasting effective for preventing ovarian hyperstimulation syndrome in patients receiving a gonadotropin-releasing hormone antagonist during an in vitro fertilization cycle?

OBJECTIVE

To report two cases of coasting during receipt of GnRH antagonists.

DESIGN

Case report.

SETTING

University hospital.

PATIENT(S)

One 27-year-old and one 28-year-old woman, both with risk factors for the ovarian hyperstimulation syndrome (OHSS).

INTERVENTION(S)

Two IVF treatments during which hMG treatment was stopped until E2 decreased to a safer level during receipt of GnRH antagonist.

MAIN OUTCOME MEASURE(S)

Development of OHSS and pregnancy.

RESULT(S)

Embryos were transferred in both women. Neither woman developed OHSS and one ongoing pregnancy was obtained.

CONCLUSION(S)

Coasting is feasible when a GnRH antagonist is used during IVF. Further studies are needed to evaluate its preventive role in OHSS.

[Mass treatment of onchocerciasis in 1996]

Mass treatment of onchocerciasis has changed radically in the last 20 years. With implementation of the Onchocerciasis Control Programme (OCP), use of insecticides to control vector larvae has been effective but has not been extended to all infected areas due to the cost. The consequences of this problem have been lessened thanks to ivermectin, an effective drug that can be administered in a single yearly dose. Although ivermectin does not appear to induce major side-effects, surveillance is necessary after administration in polyparasitized subjects living in zones where loaiasis is present and in hypermicrofilaremic subjects. To assist in the fight against onchocerciasis, ivermectin is distributed free of charge through the Mectizan Foundation by Merck Laboratories. Inexpensive community distribution programs with active participation of the populations at risk have demonstrated their usefulness. The results of mass treatment through the Mectizan Foundation have been excellent. Non-governmental organizations and in particular the Organization for the Prevention of Blindness (OPB) have become increasingly involved in the fight against onchocerciasis. The campaign conducted by the OPB in Mali, Senegal and Guinea illustrate this involvement. The role of non-governmental organizations expanded greatly with the implementation of the APOC programme supported by the World Bank.

[Treatment of shoulder dislocation and the prevention of its recurrence]

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.

Characterization of the sat4 gene encoding a streptothricin acetyltransferase in Campylobacter coli BE/G4

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.

A randomised controlled trial to test equivalence between retinyl palmitate and beta carotene for vitamin A deficiency

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.

Sequence requirements for target activity in site-specific recombination mediated by the Int protein of transposon Tn 1545

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.

[Percutaneous diagnostic angioscopy. Primary lesions]

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.

Efficacy of massive oral doses of retinyl palmitate and mango (Mangifera indica L.) consumption to correct an existing vitamin A deficiency in Senegalese children

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.

Conjunctival impression cytology with transfer as a field-applicable indicator of vitamin A status for mass screening

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.

Genetic basis of tetracycline resistance in clinical isolates of Listeria monocytogenes

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.

Assessment of vitamin A deficiency in the Republic of Djibouti

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.

An integrative vector exploiting the transposition properties of Tn1545 for insertional mutagenesis and cloning of genes from gram-positive bacteria

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.

Nucleotide sequences specific for Tn1545-like conjugative transposons in pneumococci and staphylococci resistant to tetracycline

The distributions of tet(M) and conjugative transposons related to Tn1545 were studied by hybridization in 47 clinical isolates of Streptococcus pneumoniae resistant to tetracycline. Resistance to tetracycline was always associated with resistance to minocycline and was due to the presence of the tet(M) gene. Association of tet(M) with int-Tn, the gene encoding the protein required for the movements of Tn1545-like transposons, was found in all but one strain of S. pneumoniae. In contrast, int-Tn was detected in only 2 of 37 strains of Staphylococcus spp. harboring tet(M).

Shuttle vectors containing a multiple cloning site and a lacZ alpha gene for conjugal transfer of DNA from Escherichia coli to gram-positive 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.

Prevalence of malnutrition and vitamin A deficiency in the Diourbel, Fatick, and Kaolack regions of Senegal: a controlled study

Two hundred and six Senegalese preschool children included in an epidemiological study were selected by their results from impression cytology with transfer (ICT) for assessment of their nutritional state by means of biological variables and for assessment of the diagnostic values of the ICT. A problem of protein-calorie malnutrition existed (transthyretin and retinol-binding protein concentrations were low) associated with vitamin A deficiency (retinol concentrations were low). The sensitivity and specificity of the ICT defined with respect to retinol (threshold fixed at 0.35 mumol/L) varied with the classification criteria of ICT and seemed to be fairly insensitive but specific.

Prevalence of malnutrition and vitamin A deficiency in the Diourbel, Fatick, and Kaolack regions of Senegal: epidemiological study

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.

Prevalence of malnutrition and vitamin A deficiency in the Diourbel, Fatick, and Kaolack regions of Senegal: feasibility of the method of impression cytology with transfer

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.

Gene homogeneity for aminoglycoside-modifying enzymes in gram-positive cocci

Aminoglycoside-resistant strains of Staphylococcus and Enterococcus, approximately 500 of each, were screened by dot blot hybridization for the presence of genes encoding aminoglycoside-modifying enzymes. The MICs of various aminoglycosides for the strains were determined, and the enzyme contents of the cells were inferred from the resistance phenotypes. The agreements (in percent) of the hybridization results with the deduced enzyme contents for Staphylococcus and Enterococcus species were, respectively, 80 and 87.6 for ANT(6) (aminoglycoside nucleotidyltransferase), 99.8 and 100 for both APH(3') (aminoglycoside phosphotransferase) and APH(2")-AAC(6') (aminoglycoside acetyltransferase), and 100 and 100 for ANT(4'). The weak correlation obtained with the probe for ANT(6) was due to the fact that gram-positive cocci can also be streptomycin resistant by synthesis of APH(3") or ANT(3")(9) and by ribosomal mutation. The remaining probes appeared to be specific: they hybridized with all the resistant clinical isolates but not with the susceptible strains. These results indicate that, except for streptomycin, nucleic acid hybridization is a valid approach for the detection and characterization of aminoglycoside resistance in gram-positive cocci.

The integration-excision system of the conjugative transposon Tn 1545 is structurally and functionally related to those of lambdoid phages

Excision of Tn1545 and related conjugative transposons of Gram-positive bacteria occurs by reciprocal site-specific recombination between non-homologous regions of the transposon-target junctions. Excisive recombination requires two transposon-encoded proteins designated Xis-Tn and Int-Tn. We have shown that, following excision, Tn1545 is a circular structure with ends separated by either of the two hexanucleotides that were present at the transposon-target junctions. Using a trans-complementation assay, we have demonstrated that Int-Tn is able to catalyse in vivo integration of a circular intermediate of Tn1545 defective for integration and excision. comparison of integration sites suggests that limited sequence homology at the vicinity of the recombining sites is required for integration of the element. These data support the hypothesis that the integration/excision systems of conjugative transposons from Gram-positive cocci and of lambdoid phages from Gram-negative bacilli have evolved from a common ancestor.

Emergence of 4',4"-aminoglycoside nucleotidyltransferase in enterococci

Enterococcus faecium BM4102 was resistant to macrolide-lincosamide-streptogramin B-type (MLS) antibiotics; tetracycline-minocycline; and high levels of kanamycin, neomycin, tobramycin, and dibekacin but not gentamicin. This aminoglycoside resistance phenotype is new in enterococci. The genes conferring resistance to aminoglycosides and MLS antibiotics in this strain were carried on a plasmid, pIP810, that was self-transferable to to other Enterococcus strains. Resistance to tobramycin and structurally related aminoglycosides, kanamycin, neomycin, and dibekacin, was due to synthesis of a 4',4"-aminoglycoside nucleotidyltransferase. Homology was detected by hybridization between pIP810 DNA and a probe specific for a gene encoding an enzyme with identical site specificity in staphylococci. The bacteriostatic activity of amikacin apparently was not affected by the presence of the enzyme, although it was modified in vitro. However, the bactericidal activity of amikacin and the synergism of this aminoglycoside with penicillin were abolished.

Transferable plasmid-mediated antibiotic resistance in Listeria monocytogenes

A strain of Listeria monocytogenes, isolated from a patient with meningoencephalitis, was resistant to chloramphenicol, erythromycin, streptomycin, and tetracycline. The genes conferring resistance to these antibiotics were carried by a 37-kb plasmid, pIP811, that was self-transferable to other L monocytogenes cells, to enterococci-streptococci, and to Staphylococcus aureus. The efficacy of transfer and the stability of pIP811 were higher in enterococci-streptococci than in the other gram-positive bacteria. As indicated by nucleic acid hybridisation, the genes in pIP811 conferring resistance to chloramphenicol, erythromycin, and streptomycin were closely related to plasmid-borne determinants that are common in enterococci-streptococci. Plasmid pIP811 shared extensive sequence homology with pAM beta 1, the prototype broad host range resistance plasmid in these two groups of gram-positive cocci. These results suggest that emergence of multiple antibiotic resistance in Listeria spp is due to acquisition of a replicon originating in enterococci-streptococci. The dissemination of resistance to other strains of L monocytogenes is likely.

[Percutaneous angioscopy in the diagnosis of arteriopathies of the lower limbs]

Because of the poor specificity of the arteriography, the authors have performed a percutaneous angioscopy before every angioplasty of the arteries of lower limbs for nearly 3 years. They define the angioscopy and describe materials and technique. The percutaneous route without surgery and without anesthesia underlines the originality of the technique. The great difficulty is to counter-pulse the arterial inflow. The rate of saline irrigation and all the means of arterial blockade are described. In the second part, the "elementary images" are classified. The authors insist on the specificity of the angioscopy in the interpretation of arterial obstructions. Because of this specificity, the right treatment can be applied to any type of lesion. Angioscopy permits to foresee endoluminal surgery technique.

Molecular characterization of two proteins involved in the excision of the conjugative transposon Tn1545: homologies with other site-specific recombinases

Excision is probably the initial and rate-limiting step of the movements of conjugative transposons of Gram-positive bacteria such as Tn916 and Tn1545. We have shown, by molecular cloning and DNA sequencing, that a 2058 bp Sau3A right-junction fragment of transposon Tn1545 specifies two gene products that are involved in the excision of the element. The DNA sequence of these genes, designated orf1 and orf2, has been determined and the corresponding proteins, ORF1 and ORF2, have been identified in a bacterial cell-free coupled transcription-translation system. These proteins are freely diffusible since they are able to trans-complement in vivo a deletion derivative of Tn1545 defective for excision. Using an in vivo complementation assay, we have demonstrated that ORF2 alone is able to catalyse excision and that ORF1 strongly stimulates the activity of ORF2. We also found that ORF1 and ORF2 display local homology with, respectively, proteins Xis and Int from lamboid phages, which suggests that these excision systems have a common origin. Based on the functional properties of the integrase of bacteriophage lambda, on the analysis of the nucleotide sequence of the junction fragments and of the target before insertion and after excision, a model is proposed for ORF2-catalysed excision of Tn1545 and related conjugative transposons.

Conjugative plasmid transfer from Enterococcus faecalis to Escherichia coli

The possibility of transfer of genetic information by conjugation from gram-positive to gram-negative bacteria was investigated with a pBR322-pAM beta 1 chimeric plasmid, designated pAT191. This shuttle vector, which possesses the tra functions of the streptococcal plasmid pAM beta 1, was conjugatively transferred from Enterococcus faecalis to Escherichia coli with an average frequency of 5 x 10(-9) per donor colony formed after mating.

Nucleotide sequence of the kanamycin resistance determinant of the pneumococcal transposon Tn1545: evolutionary relationships and transcriptional analysis of aphA-3 genes

The nucleotide sequence of the kanamycin resistance determinant aphA-3 encoded by transposon Tn1545 from Streptococcus pneumoniae was determined and compared to those of plasmids pJH1 and pIP1433 from Streptococcus faecalis and Campylobacter coli, respectively. The three sequences were found to be identical and differed by two substitutions and the deletion of a codon from that of plasmid pSH2 from Staphylococcus aureus. Comparison of the 5' noncoding sequences indicated that the regions containing the aphA-3 gene in pJH1 and in Tn1545 evolved independently by deletion from a sequence similar to that found in pIP1433. In the latter plasmid, aphA-3 is transcribed from a promoter, P1, which is flanked by two 12-base pair direct repeats. The rearrangement observed in pJH1 removed one of these recombinogenic sites and altered the -10 and 3' flanking sequences of P1. The promoter thus generated. P1', allows expression of similar level of kanamycin resistance as P1. However, fusion experiments carried out with a promotorless chloramphenicol acetyltransferase gene indicated that the canonical promoter P1 is significantly less efficient than P1'. From analysis of the thermodynamic properties of these promoters, we conclude that this difference in strength reflects the melting properties of the -10 sequences. The transition from pIP1433 to pJH1 may correspond to the progression of a molecule structurally unstable to a more stable one combined with the need to maintain an efficient promoter upstream of the aphA-3 gene. The deletion event in Tn1545, which occurred between the two 12-base pair directly repeated sequences, removed P1 in its entirety.(ABSTRACT TRUNCATED AT 250 WORDS)

Tn1545: a conjugative shuttle transposon

Tn1545, from Streptococcus pneumoniae BM4200, confers resistance to kanamycin (aphA-3), erythromycin (ermAM) and tetracycline (tetM). The 25.3 kb element is self-transferable to various Gram-positive bacterial genera where it transposes. Tn1545 was cloned in its entirety in the recombination deficient Escherichia coli HB101 where it was unstable. The three resistance genes aphA-3, ermAM and tetM were expressed but were not transferable to other E. coli cells. Tn1545 transposed from the hybrid plasmid to multiple sites of the chromosome of its new host. The element re-transposed, at a frequency of 5 X 10(-9), from the chromosome to various sites of a conjugative plasmid where it could be lost by apparently clean excision. The element transformed and transposed to the chromosome of Bacillus subtilis. The properties of the conjugative shuttle transposon Tn1545 may account for the recent emergence of genes from Gram-positive bacteria in Gram-negative organisms.

Physical analysis of the conjugative shuttle transposon Tn1545

The conjugative shuttle transposon Tn1545 from Streptococcus pneumoniae confers resistance to kanamycin (aphA-3), erythromycin (ermAM), and tetracycline (tetM). The 25.3-kb element is self-transferable to various gram-positive bacterial genera where it transposes. Tn1545 is also capable of transposition, but not of conjugation, after cloningoff Escherichia coli. Analysis of the element by restriction endonucleases, molecular cloning, electron microscopy of heteroduplexes, DNA hybridization, and sequencing allowed us to establish a physical map of Tn1545, localize the resistance genes, determine their direction of transcription, and compare them with other characterized resistance determinants, and show that Tn1545 is not flanked by large terminal repeated sequences in opposite orientation.

Transposable multiple antibiotic resistance in Streptococcus pneumoniae

A mobile genetic element, designated Tn1545, was detected in the chromosome of Streptococcus pneumoniae BM4200, a clinical isolate multiply resistant to antibiotics. The 25.3 kb element conferred resistance to kanamycin and structurally related aminoglycosides by synthesis of a 3'-aminoglycoside phosphotransferase type III (aphA-3), to macrolide-lincosamide-streptogramin B-type antibiotics (ermAM), and to tetracycline (tetM). Tn1545 was self-transferable to a recombination deficient S. faecalis strain where it was able to transpose to various sites, induce insertional mutations and was apparently cleanly excised. The element also conjugated to and transposed to the chromosome of S. faecalis, S. lactis, S. diacetylactis, S. cremoris, S. sanguis, Staphylococcus aureus, and Listeria monocytogenes. The properties of the conjugative transposon Tn1545 could account for the sudden emergence, rapid dissemination, and stabilisation of multiple resistance to antibiotics in S. pneumoniae in the absence of plasmids.

Emergence of aminoglycoside 3-N-acetyltransferase IV in Escherichia coli and Salmonella typhimurium isolated from animals in France

We studied two outbreaks of calf salmonellosis caused by apramycin and gentamicin-resistant Salmonella typhimurium strains. In both cases, the responsible strains were resistant to ampicillin, chloramphenicol, kanamycin, streptomycin, tetracycline, and trimethoprim; one strain was also resistant to nalidixic acid in one outbreak. A systematic survey of the intestinal Escherichia coli strains of calves from the two affected flocks showed that 11 of 24 animals sampled were also colonized by apramycin- and gentamicin-resistant E. coli strains. These isolates belonged to four biotypes and were resistant to ampicillin, chloramphenicol, kanamycin, streptomycin, tetracycline, trimethoprim, and nalidixic acid. All of the strains were resistant to high levels of apramycin (MICs, 512 to 1,024 micrograms/ml) and to gentamicin (MICs, 8 to 32 micrograms/ml), and these resistances were always transferred en bloc. In S. typhimurium, this coresistance was borne by plasmids that were approximately 39 kilobases long (outbreak 1) or 90 kilobases long (outbreak 2), whereas in E. coli, the coresistance was due to plasmids that were approximately 110 kilobases long in both outbreaks. The two plasmids of Salmonella and four plasmids of E. coli encoded type IV aminoglycoside 3-N-acetyltransferases. The intensive use of curative and preventive treatments in calf production could be responsible for the emergence of enzymic resistance to apramycin and gentamicin.

Plasmid-mediated resistance to lincomycin by inactivation in Staphylococcus haemolyticus

Staphylococcus haemolyticus BM4610 was resistant to high levels of lincomycin and susceptible to macrolides, clindamycin, and streptogramins. This resistance phenotype, not previously reported for a human clinical isolate, was due to inactivation of the antibiotic. The gene conferring resistance to lincomycin in strain BM4610 was carried by a 2.5-kilobase plasmid, pIP855, which was cloned in Escherichia coli. Plasmid pIP855 caused inactivation of both lincomycin and clindamycin in S. haemolyticus and in E. coli but conferred detectable resistance to lincomycin only in S. haemolyticus and to clindamycin only in E. coli.

Characterization of high-level aminoglycoside resistance in a strain of Streptococcus pneumoniae

The aminoglycoside phosphotransferase (APH)(3')(5'')-III has been characterized from Streptococcus pneumoniae BM4200, which is resistant to high levels of aminoglycosides. The phosphotransferase was apparently chromosomally-encoded and was responsible for the high-level resistance. The enzyme was not notably pH-dependent, was heterogeneous after isoelectric focusing, with pI values of approximately 4.8 and 5.1, and had an apparent molecular weight of 32 500 after SDS-PAGE.

The chromosomal 3',5"-aminoglycoside phosphotransferase in Streptococcus pneumoniae is closely related to its plasmid-coded homologs in Streptococcus faecalis and Staphylococcus aureus

The apparently chromosomally encoded 3',5"-aminoglycoside phosphotransferase (type III), from the high-level aminoglycoside-resistant Streptococcus pneumoniae BM4200, was compared with homologous enzymes coded for by the plasmids pJH1 and pSH2, originally isolated from Streptococcus faecalis and Staphylococcus aureus, respectively, and also found in a wild strain of S. aureus, BM4600. The enzymes appeared to be indistinguishable, and we conclude that the gene encoding 3',5"-aminoglycoside phosphotransferase (type III) can cross generic barriers within gram-positive cocci.

Transferable plasmid-mediated antibiotic resistance in Acinetobacter

Acinetobacter calcoaceticus strain BM2500 was resistant to ampicillin, aminoglycoside-aminocyclitols, chloramphenicol, sulfonamides, and high levels of trimethoprim. Resistance to ampicillin was due to the presence of a beta-lactamase (TEM-1) and the aminoglycoside-aminocyclitol resistance was mediated by phosphotransferase (APH(3')(5")I) and adenylyltransferase (AAD(3)(9] activities. The resistance genes were carried by a 167 kilobase plasmid, pIP1031, belonging to incompatibility group 6-C; the plasmid was self-transferable, at extremely low frequency, to Escherichia coli by conjugation. Plasmid pIP1031 DNA was analyzed by agarose gel electrophoresis following restriction endonuclease digestion, by nucleic acid hybridization, and by CsCl analytical density gradient ultracentrifugation. The results support the hypothesis that plasmid pIP1031 may have been acquired recently by strain BM2500.

Aminoglycoside-modifying enzyme content of a multiply resistant strain of Streptococcus faecalis

Streptococcus faecalis strain BM6217 was resistant to high levels of all the clinically useful aminoglycoside antibiotics. This broad aminoglycoside resistance was mediated by constitutively synthesized phosphotransferase, acetyltransferase, and adenylyltransferase activities. It was inferred that phosphorylation occurred at the 3', 5", and 2"-hydroxyl groups, acetylation at the 6'-amino group, and adenylylation, probably, at the 6-hydroxyl group of the aminoglycosides. Strain BM6217 remained susceptible to the aminocyclitol spectinomycin but the combination of penicillin G with that antibiotic appeared antagonistic to this strain.

A plasmid which does not encode the aminoglycoside phosphotransferase in the butirosin-producing strain of Bacillus circulans

Bacillus circulans NRRL B-3312 produces the aminoglycoside antibiotic butirosin and encodes an aminoglycoside 3'-phosphotransferase. We detected a 48 kilobase plasmid, pIP850, in this strain; this was analyzed by agarose gel electrophoresis following digestion with EcoRI restriction endonuclease and by nucleic acid hybridization. The results obtained indicate that plasmid pIP850 does not carry the structural gene for the aminoglycoside modifying enzyme.