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Biomedical subjects

Philippe Martel

Publications and source records attributed to Philippe Martel.

7 recordsLinked to original sources
PubMed2006

[Transient ischemic stroke].

According to the new definition proposed by the TIA working group, transient ischemic stroke (TIA) is "a brief episode of neurologic dysfunction caused by focal brain or retinal ischemia, with clinical symptoms typically lasting less than one hour, and without evidence of acute infarction." Patient presenting with a TIA should be investigated and treated urgently because the risk of ischemic stroke is about 10% at one month with 50% of these events occurring during the first 48 hours. Atherosclerosis, cardioembolism and small vessel disease account for the majority of TA. Aspirin should be started as soon as possible after brain imaging has been performed. Other treatment such as oral anticoagulants or carotide surgery may be necessary, depending on the result of the electronical work up.

Administration, Oral↗
PubMed2005

M3-like muscarinic receptors mediate Ca2+ influx in rat mesencephalic GABAergic neurones through a protein kinase C-dependent mechanism.

GABAergic neurones in the mesencephalon are important regulators of dopamine neurones. Cholinergic projections from mesopontine nuclei preferentially synapse onto these GABAergic neurones, thus suggesting that ACh can regulate dopamine neurones indirectly by modulating GABAergic interneurones. Muscarinic receptors mediate excitation of these interneurones through a Ca(2+)-dependent mechanism. Using a mesencephalic primary culture model, we show here that muscarine (10 microM) increases intracellular Ca2+ concentrations ([Ca2+]i) in GABAergic interneurones. Compatible with previous anatomical data, our pharmacological studies further suggest that the M3 receptor is the primary mediator of this increase. The rise in [Ca2+]i induced by muscarine was not activity-dependent but required influx of Ca2+ from the extracellular medium. Consistent with the known coupling of the M3 receptor to PKC, the effect of muscarine was blocked by bisindolylmaleimide, a selective PKC antagonist. The effect of muscarine was inhibited by SKF 96365 and verapamil, drugs known to block non-selective cationic channels such as those formed by transient receptor potential (TRPC) proteins. Finally, GABAergic neurones were found to be immunopositive for TRPC1, 3, 5 and 6. Taken together, these results suggest that the Ca(2+)-dependent regulation of mesencephalic GABAergic neurones by muscarinic receptors requires activation of some receptor-operated Ca2+ channels through a PKC-dependent mechanism.

Analysis of Variance↗
PubMed2003

Paraneoplastic pemphigus is associated with the DRB1*03 allele.

Pemphigus is a group of autoimmune blistering diseases caused by autoantibodies directed against keratinocyte adhesion molecules. Pemphigus vulgaris (PV) and pemphigus foliaceus (PF), in which autoantibodies bind, respectively, to desmoglein 3 and desmoglein 1, are strongly associated with HLA-class II DR4 and DR14 alleles. In paraneoplastic pemphigus (PNP), a rare variant associated with neoplasia, autoantibodies target proteins of the plakin family in addition to desmogleins 1 and 3. The presence of anti-desmoglein antibodies in all types of pemphigus raises the question of common molecular mechanisms of susceptibility, particularly similar MHC-class II allele associations, in the different forms of the disease. HLA-DRB1 typing was performed in 13 PNP patients and results were compared to those obtained from 84 healthy controls, 37 PV and 31 PF patients. Our data demonstrate a significant association of PNP with HLA-DRB1*03 allele which was found in 61.5% of the patients, whereas DRB1*04 and DRB1*14 appear not to be involved in PNP susceptibility. Therefore, the HLA-genetic background of PNP differs from that of other types of pemphigus, which suggests that distinct mechanism(s) initiate(s) the immunological response in this form of pemphigus.

HLA-DR Antigens↗
PubMed2002

Crohn's colitis: experience with segmental resections; results in a series of 84 patients.

BACKGROUND: Colonic Crohn's disease can be treated surgically by total colonic resection or by segmental colonic resection. The aim of this study was to analyze the outcomes of patients treated by segmental colectomy for colonic Crohn's disease. STUDY DESIGN: Among 413 patients undergoing operations for Crohn's disease, 84 had a segmental colectomy (cases of terminal ileitis with limited cecal involvement were not included). Postoperative complications, mortality, recurrence, and functional results were studied. RESULTS: Eighty-four patients (51 women, 33 men), with a mean age of 34 years, underwent operation (right segmental colectomy: 55%; left segmental colectomy: 40%; associated right and left colectomy: 5%). A stoma was established in 27 patients (32%). Operative mortality was zero. Twelve patients (14%) had postoperative complications (including six cases of anastomotic leakage). The mean and median followup times were 111 and 104 months, respectively (range: 15 to 276 months) for the 82 patients with followup available. Thirty-six patients had to undergo reoperation, and the mean time to reoperation was 4.5 years. Twenty-six of these patients suffered colonic recurrence and were treated by total colectomy (n = 9) or new segmentary resection (n 17). The only factor that correlated with the risk of recurrence was youth. At the end of the study, 13 patients still had a stoma. Seventy-five percent of the patients without stoma had less than three bowel movements per day, and 80% were fully satisfied or satisfied, CONCLUSIONS: There is no evidence of a higher risk of postoperative complications, surgical recurrence, or the requirement of a permanent stoma in patients suffering from colonic Crohn's disease who are treated according to a "bowel-sparing policy" compared with patients treated with more extensive resections published in the literature. Prospective randomized studies are needed to validate this observation.

Adult↗
PubMed2002

Comparative anatomical study of division of the ileocolic pedicle or the superior mesenteric pedicle for mesenteric lengthening.

BACKGROUND: Lengthening of the mesentery by vascular division may be necessary to perform an ileal pouch-anal anastomosis without tension. The aim of this study was to compare, in fresh cadavers, the increase in mesentery length after division of the ileocolic pedicle (ICP) and the superior mesenteric pedicle (SMP). METHODS: Total colectomy was performed in 12 fresh cadavers, which were then randomly divided into two groups. Pouch-anal anastomosis was performed with division of the ICP in one group of six cadavers and with division of the SMP in the other. The ileum was measured and the increase in length was recorded and compared statistically. RESULTS: The mean(s.d.) increase in length was 3.0(0.8) cm after ICP division and 6.5(1.1) cm after SMP division (P < 0.001). The distance between the end of the ileum and the point giving the greatest length was 25.5(5.0) cm in the ICP group and 46.8(4.2) cm in SMP group (P < 0.001). CONCLUSION: In fresh cadavers, the increase in mesenteric length was greater after SMP division than after ICP division, but if pouch-anal anastomosis is performed a short segment of small bowel must be removed.

Aged↗