Biomedical subjects

L Gautier

Publications and source records attributed to L Gautier.

4 recordsLinked to original sources

PubMed2001

Comparative genomics of Listeria species.

Listeria monocytogenes is a food-borne pathogen with a high mortality rate that has also emerged as a paradigm for intracellular parasitism. We present and compare the genome sequences of L. monocytogenes (2,944,528 base pairs) and a nonpathogenic species, L. innocua (3,011,209 base pairs). We found a large number of predicted genes encoding surface and secreted proteins, transporters, and transcriptional regulators, consistent with the ability of both species to adapt to diverse environments. The presence of 270 L. monocytogenes and 149 L. innocua strain-specific genes (clustered in 100 and 63 islets, respectively) suggests that virulence in Listeria results from multiple gene acquisition and deletion events.

Adaptation, Physiological↗

PubMed1998

Mobilization of Philadelphia-negative peripheral blood progenitor cells with chemotherapy and rhuG-CSF in chronic myelogenous leukaemia patients with a poor response to interferon-alpha.

The purpose of this cooperative study was to evaluate the quantity and quality of Ph1-negative progenitor cells mobilized in the peripheral blood of patients with chronic myelogenous leukaemia soon after aplasia induced by chemotherapy. 32 patients ineligible for allografting who were cytogenetically refractory to interferon-alpha (IFN-alpha) were entered into this study. The chronic phase varied widely, with a median duration of 17 months (range 3-90 months). All patients were treated with intensive conventional chemotherapy regimens and recombinant human granulocyte colony-stimulating factor (rhuG-CSF, lenograstim). Peripheral blood progenitor cells (PBPC) were harvested by leukaphereses during early recovery from chemotherapy-induced aplasia. A total of 119 leukaphereses were performed. Median numbers of CD34+ cells and CFU-GM collected were 2.04 x 10(6)/kg and 2 9 x 10(4)/kg, respectively. There was a significant correlation between white cell count and number of CD34+ cells in the leukaphereses (P = 0.0001, r2 = 0.41, n = 104). A strict correlation between the number of CD34+ cells and CFU-GM in the leukapheretic product (P = 0.0001, r2 = 0.39, n = 110) was observed. 21% of evaluable patients (6/29) achieved a complete cytogenetic remission in the leukapheretic product and the other four patients achieved a major cytogenetic response for an overall response of 35% (10/22 patients). To date, 16 patients have been autografted and are alive. Five of them are Ph1-negative (three patients) or partially Ph1-negative (two patients). In conclusion, despite the high-risk characteristics of this study population, Ph1-negative PBPC were successfully mobilized in more than one-quarter of patients using a chemotherapy plus rhuG-CSF regimen. The importance of this achievement is increased by the current lack of other practical methods of rescuing Ph-negative cells in such patients.

Adjuvants, Immunologic↗

PubMed1998

Collection of Ph-negative progenitor cells with granulocyte-colony stimulating factor in patients with chronic myeloid leukaemia who respond to recombinant alpha-interferon.

This study aimed to demonstrate that sufficient Ph-negative blood progenitors could be collected following administration of glycosylated rhG-CSF (lenograstim) to patients with Philadelphia chromosome (Ph)-positive chronic myeloid leukaemia (CML) who responded to recombinant alpha-interferon (alpha-IFN) (Ph-positive marrow metaphases < 35%). 23 patients received lenograstim (150 microg/m2) once daily for a median of 9 d. Peak circulating numbers of white blood cells (36.4 x 10(9)/l), CD34+ cells (24/ microl) and colony-forming unit-granulocyte-macrophage (CFU-GM; 1346.5/ml) occurred at a median of day 8, day 8 and day 7, respectively. Two to six (median three) leukaphereses (LK) were performed from days 5 to 12. The median number of mononuclear cells (MNC), CD34+ cells and CFU-GM collected per patient was 7.35 x 10(8/)kg, 2.72 x 10(6)/kg and 10.23 x 10(4)/kg, respectively. 22/23 patients had LK which contained either 10(4) CFU-GM/kg and/or 10(6) CD34+ cells/kg; 47LK (from 20/22 patients) were evaluable for cytogenetics. The median percentage of Ph-positive cells was 0, and 43/47 LK (91%) contained <35% Ph-positive cells; 25 (53%) were entirely negative. Sixteen of 20 evaluable patients had one or more LK with <35% Ph-positive cells, and 12 had at least one 100% Ph-negative LK. Mobilization and collection of Ph-negative cells were not influenced by the dose or duration of alpha-IFN administration before (or during) lenograstim administration or by the quality of cytogenetic response (complete v major) during lenograstim administration. No significant side-effects were observed. Thus, lenograstim administration can result in satisfactory Ph-negative blood progenitor cell collection. Autologous transplantation of such cells may be used when indicated.

Adjuvants, Immunologic↗

PubMed1997

[Coronary angioscopy].

Coronary angioscopy evaluates the composition of the atherosclerotic plaque by direct examination of the arterial wall. The angioscope is fitted with a balloon which prevents assessment of the proximal segment of the vessels. The fibre optic system provides and excellent view of the mid and distal segments of the coronary arteries. The coronary arteries appear smooth and white on angioscopy. The atherosclerotic plaque is a white or yellowish incursion. Unstable plaques are characterised by the presence of thrombus. In unstable angina, thrombus is observed in 64% of cases and in 75% of cases during the first month after myocardial infarction. The colour of the plaque seems to be related to its fragility: the yellow plaque is much more common during myocardial infarction than in unstable angina (75% versus 47% of cases). Finally, after coronary angioplasty restenosis is more commonly white, covered by neo-intimal proliferation. Angioscopy has been shown to be feasible and safe and it is a better method of identifying thrombus. At present, it is a tool for clinical research in coronary thrombosis and interventional cardiology.

Angioplasty, Balloon, Coronary↗