Biomedical subjects

O Taboureau

Publications and source records attributed to O Taboureau.

8 recordsLinked to original sources

PubMed2005

Improving on nature's defenses: optimization & high throughput screening of antimicrobial peptides.

Antimicrobial peptides (AMPs) are ubiquitous in nature where they play important roles in host defense and microbial control. Despite their natural origin, antimicrobial spectrum and potency, the lead peptide candidates that so far have entered pharmaceutical development have all been further optimized by rational or semi-rational approaches. In recent years, several high throughput screening (HTS) systems have been developed to specifically address optimization of AMPs. These include a range of computational in silico systems and cell-based in vivo systems. The in silico-based screening systems comprise several computational methods such as Quantitative Structure/Activity Relationships (QSAR) as well as simulation methods mimicking peptide/membrane interactions. The in vivo-based systems can be divided in cis-acting and trans-acting screening systems. The cis-acting pre-screens, where the AMP exerts its antimicrobial effect on the producing cell, allow screening of millions or even billions of lead candidates for their basic antimicrobial or membrane-perturbating activity. The trans-acting screens, where the AMP is secreted or actively liberated from the producing cell and interacts with cells different from the producing cell, allow for screening under more complex and application-relevant conditions. This review describes the application of HTS systems employed for AMPs and lists advantages as well as limitations of these systems.

Animals↗

PubMed2001

Database mining applied to central nervous system (CNS) activity.

A data set of 389 compounds, active in the central nervous system (CNS) and divided into eight classes according to the receptor type, was extracted from the RBI database and analyzed by Self-Organizing Maps (SOM), also known as Kohonen Artificial Neural Networks. This method gives a 2D representation of the distribution of the compounds in the hyperspace derived from their molecular descriptors. As SOM belongs to the category of unsupervised techniques, it has to be combined with another method in order to generate classification models with predictive ability. The fuzzy clustering (FC) approach seems to be particularly suitable to delineate clusters in a rational way from SOM and to get an automatic objective map interpretation. Maps derived by SOM showed specific regions associated with a unique receptor type and zones in which two or more activity classes are nested. Then, the modeling ability of the proposed SOM/FC Hybrid System tools applied simultaneously to eight activity classes was validated after dividing the 389 compounds into a training set and a test set, including 259 and 130 molecules, respectively. The proper experimental activity class, among the eight possible ones, was predicted simultaneously and correctly for 81% of the test set compounds.

Central Nervous System↗

PubMed1988

Acute monoblastic leukemia with osteosclerosis and extensive myelofibrosis.

A 4-month-old infant was admitted with a monoblastic infiltration of the skin associated with osteosclerosis. Both lesions spontaneously disappeared within a few months, but 2 years later, a monoblastic leukemia occurred that was associated with marked skin erythema and myelofibrosis. Skin and bone marrow specimens showed a monoblastic infiltration with numerous intermingled mast cells of normal appearance. Whether myelofibrosis was a feature of a systemic mastocytosis or of the leukemic process is discussed in this case.

Humans↗

PubMed1988

Ifosfamide is an active drug in Wilms' tumor: a phase II study conducted by the French Society of Pediatric Oncology.

Twenty-one patients with advanced Wilms' tumor entered a phase II study with high-dose ifosfamide (3 g/m2 over two days every 15 days). Mesna and hyperhydration were associated with minimal bladder toxicity. After two courses, five partial responses and six complete responses were observed. Ten patients did not respond. The median duration of response was 2 months (range, 1 to 7). Therapy was delayed because of leukopenia for 1 or 2 weeks in only three cases. Fever and infection were not observed. Seven patients presented with hematuria, three of whom were among the 17 patients coadministered mesna, which did not interfere with subsequent therapy.

Adolescent↗

PubMed1987

Ultrasonographic findings in thymic lymphoma in children.

The sonographic manifestations of thymic involvement by T lymphoblastic non-Hodgkin's lymphoma/leukaemia in 6 children are presented. The criteria which may help in its differentiation from a normal thymus gland are reviewed. Hypoechoic and non-homogeneous large masses are the most typical presentation of thymic infiltration. Fixity of tumour and compression of surrounding structures are the most important associated signs with pleural and pericardial effusions. In children, ultrasonography of the mediastinum can play a role by establishing the nature of anterior masses.

Child, Preschool↗

PubMed1987

[Treatment of febrile episodes in neutropenic children by ceftazidime combined with netilmicin. Results of a multicenter study apropos of 88 cases].

Infection is the most important cause of mortality in leucopenic patients. A broad spectrum antibiotic therapy is imperative in febrile and neutropenic patients. In a multicentric study we have used ceftazidime (100 mg/kg/d) and netilmicin (6 mg/kg/d) in 88 children (fever greater than or equal to 38.5 degrees C, neutropenia less than 500/mm3) treated for acute leukemias (59), non Hodgkin lymphomas (13) or solid tumors (16). Median age was 7 years (2 months-16 years). In patients who continued to remain febrile, vancomycin (40 mg/kg/d) was added after 48 hours. The effective treatment was continued until a neutrophil count greater than 1,000/mm3. The first combination (ceftazidime + netilmicin) was effective in 64 children (73%) and the second combination (ceftazidime + netilmicin + vancomycin) in 11 patients. Bacteria were isolated in 39 children: Escherichia coli: 9, Staphylococcus epidermidis: 9, Staphylococcus aureus: 8, Streptococcus: 6, Pseudomonas aeruginosa: 3, Streptococcus pneumoniae: 1, Haemophilus: 1, Klebsiella pneumoniae: 1, Proteus: 1, Serratia: 1, Flavobacterium: 1. In these 39 patients, 30 became apyretic with ceftazidime and netilmicin and 6 after vancomycin. All blood culture were negative after the first combination. The median duration of antibiotic therapy was 14 days (5-9 days: 28, 10-20 days: 43, greater than 20 days: 17). There were no death, no superinfection. Tolerance was good without kidney or liver or biological perturbation. We conclude that the combination ceftazidime and netilmicin is effective in neutropenic children.

Adolescent↗

PubMed1986

[Graft versus host reaction following materno-fetal transfusion. Apropos of 1 case].

After GVHR by probable maternal-foetal in utero transfusion, a male infant carrying a serious combined immune deficit (DICS) has presented a second post transfusional GVHR. On the occasion of this observation, the authors recall the main signs which permit to evoke this rare diagnosis as early as possible, as well as some main preventive measures that can be applied in current practice.

Female↗

PubMedDate not supplied

Cytogenetics and their prognostic value in childhood and adult acute lymphoblastic leukemia (ALL) excluding L3.

Cytogenetic analysis was made at diagnosis in 174 cases of ALL (101 children less than 20 years and 73 adults), excluding Burkitt's ALL (L3). In 11 children (11 per cent) insufficient material was obtained. In the remaining 90, 50 (56 per cent) had a normal karyotype, 20 (22 per cent) a hyperdiploid karyotype, five (6 per cent) a hypodiploid karyotype, 12 (13 per cent) had a translocation (including seven cases of t(1;19] and three had a pseudodiploid karyotype without translocation. Ninety-eight per cent of patients reached complete remission (CR). Median actuarial CR duration was not attained, was 50 months, 13 months, and 11 months respectively in patients with hyperdiploid, normal, hypodiploid karyotype and in patients with a translocation, the difference between subgroups being significant. In a Cox model, cytogenetics were the strongest factor predicting CR duration (p = 0.03) followed by leukocytes (p = 0.04), whereas the presence of 'bulky disease' had a borderline value (p = 0.077). Of note was that 9/17 (53 per cent) patients with a hypodiploid karyotype or a translocation had no 'risk factors' before cytogenetic analysis. In adults, cytogenetic analysis was unsuccessful in 15 (20 per cent) of patients. In the remaining 58 cases, 19 (33 per cent) had a normal karyotype, 15 (26 per cent) had a hyperdiploid, one (2 per cent) had a hypodiploid karyotype, 19 (33 per cent) had a translocation (including 12 t(9;22], and four (7 per cent) had a pseudodiploid without translocation. 73 per cent patients reached CR. Median actuarial DFS was 12.5 months. No significant differences in CR rate and CR duration were seen between cytogenetic groups, but median CR duration was slightly longer in patients with a normal karyotype (17 months) and shorter in patients with t(9;22) (8.5 months). Only 3/12 of the latter had major risk factors before cytogenetic analysis. Cytogenetic analysis is important in ALL, especially in patients with otherwise standard risk factors, as it may reveal unexpected translocations or hypodiploidy, which may require a therapeutic reinforcement.

Adolescent↗