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P Jourdan

Publications and source records attributed to P Jourdan.

At least 19 recordsLinked to original sources
PubMed2003

[Thoracic ballistic traumatisms. Wounding agents and wound ballistic].

The adequate care of thoracic ballistic traumatisms implies a good preliminary knowledge of wounding agents, and of the principles governing lesion-based ballistic, in particular the role played by the meeting with an obstacle which modifies the ballistic behaviour of the projectile, with worsened wounding effects. Authors describe the principal types of involved projectiles and their wound profile applied to the thorax, while stressing the need to treat systematically the wound and not the weapon, and on the importance of the choice of the surgical exploration way of these lesions, which conditions, as from the initial stage, the later choices of the parietal closure and rebuilding methods. The importance of parietal disrepair is therefore an essential decisional factor in the assumption of responsibility and the definition of the therapeutic strategy of these casualties.

Firearms↗
PubMed2000

Cytokines and cell surface molecules independently induce CXCR4 expression on CD4+ CCR7+ human memory T cells.

In the present study, we show that IL-2, IL-4, IL-7, and IL-15 are able to induce functional CXCR4 surface expression on resting in vitro-generated CD4+ CXCR4- CCR7+ memory T cells. Cytokine-mediated induction of CXCR4 expression was associated with an increase in CXCR4 transcription, enhanced stromal-derived factor-1-induced T cell migration in vitro, and increased susceptibility of these cells to infection with X4 strains of HIV-1. CXCR4 expression could also be induced through an alternative pathway, following coculture of these cells with CD40-activated, autologous, CD34+ progenitor-derived dendritic cells. Although these dendritic cells express transcripts for IL-7 and IL-15, addition of neutralizing anti-IL-7R and IL-15 mAbs did not block induction of CXCR4 expression. Indeed, dendritic cell-mediated up-regulation of CXCR4 expression was found to depend on CD40/CD154 and CD134/CD134L interactions. Whereas activated autologous dendritic cells induced the expression of both CXCR4 and CD25 on a portion of CCR7+ memory T cells, concomitant CD3-mediated activation of these cells further enhanced CD25 expression, but, in contrast, prevented induction of CXCR4 expression. This observation suggests that triggering of the CD134 and CD154 molecules, in contrast to TCR/CD3 complex-mediated stimulation, results in simultaneous T cell activation and CXCR4 expression. Taken together, these results show that common gamma-chain-interacting cytokines as well as signals mediated via noncognate interactions between activated dendritic cells and memory T cells are involved in the up-regulation of CXCR4 expression.

Animals↗
PubMed1999

A CD4-independent interaction of human immunodeficiency virus-1 gp120 with CXCR4 induces their cointernalization, cell signaling, and T-cell chemotaxis.

The gp120 envelope glycoprotein of human immunodeficiency virus-1 (HIV-1) interacts with the CXCR4 chemokine receptor, but it is not known whether gp120 activates CXCR4-mediated signaling cascades in the same manner as its natural ligand, SDF1alpha. We assessed the effects of wild-type gp120 and a mutant gp120 that interacts with CXCR4 but not CD4 on CD4(-)/CXCR4(+) cells and CD4(+)/CXCR4(+) cells, respectively. Under both experimental conditions, the interaction of CXCR4 and gp120 resulted in their CD4-independent cointernalization. Both molecules were translocated into early endosomes, whereas neither protein could be detected in late endosomes. Binding of gp120 to CXCR4 resulted in a CD4-independent phosphorylation of Pyk2 and an induction of chemotactic activity, demonstrating that this interaction has functional consequences. Interestingly, however, whereas SDF1alpha activated the ERK/MAP kinase pathway, this cascade was not induced by gp120. Together, these results suggest that the pathology of HIV-1 infection may be modulated by the distinct signal transduction pathway mediated by gp120 upon its interaction with CXCR4.

Antigens, CD↗
PubMed1999

TCR-mediated activation of allergen-specific CD45RO(+) memory T lymphocytes results in down-regulation of cell-surface CXCR4 expression and a strongly reduced capacity to migrate in response to stromal cell-derived factor-1.

The selective migration of functional T(h) lymphocyte subsets with different cytokine production profiles into inflamed tissue is likely to depend on the state of activation of the cells, as well as on the differential expression of various adhesion molecules and chemokine receptors. In this study, we have analyzed the effect of allergen-specific activation on the expression of the chemokine receptor CXCR4 on T lymphocytes. We show that stimulation of peripheral blood mononuclear cells from atopic patients with the allergen Der p results in down-regulation of CXCR4 surface expression on Der p-activated CD25(+)CD45RO(+) antigen-specific memory cells which was caused by a decrease in CXCR4 gene transcription and did not seem to be mediated by endogenous cytokines, such as IFN-gamma. In contrast, however, CXCR4 surface expression was enhanced on naive CD25(-)CD45RO(-) and resting CD25(-)CD45RO(+) memory T cells, as a result of the presence of endogenous IL-4, most likely produced by Der p-activated memory T cells. Antigen-specific CD25(+)CD45RO(+) T lymphocytes, purified 7 days after stimulation with Der p, had a strongly reduced capacity to migrate in response to stimulation with stromal cell-derived factor (SDF)-1, the ligand for CXCR4. Together, these results suggest that differential expression of CXCR4 on activated and resting T cells is due to the counteracting effects of TCR-mediated down-regulation and IL-4-mediated up-regulation of this chemokine receptor respectively, and furthermore indicate that antigen-activated memory T cells are unlikely to migrate into inflamed tissue in response to SDF-1.

Adult↗
PubMed1998

IL-4 induces functional cell-surface expression of CXCR4 on human T cells.

Here we report that IL-4 specifically enhances cell surface expression of CXCR4 on resting peripheral and cord blood T cells. Whereas polarized Th2 clones express variable levels of CXCR4, expression of this receptor is undetectable on polarized Th1 clones but can be induced on the latter cells as well, following short-term culture in the presence of IL-4. The IL-4-induced CXCR4 is functional since interaction with its ligand, stromal-derived factor (SDF)-1, activates the p42 MAP-kinase ERK-2. In addition, although CXCR4 expression is down-regulated following stimulation of T cells and T cell clones via CD28 or CD3 and CD2 cell surface molecules, respectively, it is re-induced by IL-4. These data indicate an important role for IL-4 in rendering CD4+ T cells susceptible to infection with HIV via CXCR4, as well as in promoting SDF-1-induced migration of these cells.

CD4-Positive T-Lymphocytes↗
PubMed1996

[Gunshot injuries of the ureter].

The increased incidence of gunshot injuries of the ureter (GIU) can be explained by increased of armed violence in some large cities and by the performance of intensive care teams, both in civilian practice and in a context of war. The discovery of a GIU, during salvage laparotomy for vascular or visceral lesions is no longer exceptional. We report 5 cases of abdomen gunshot wounds with ureteric trauma treated between 1987 and 1994 by three surgical teams. The data in the literature and the principles of ballistic wounds are analysed. Theses lesions are initially misdiagnosed diagnosis in 10 to 20% of cases, as there are no specific clinical signs, radiological opacification of urinary tract is rarely performed, and septic nature of associated lesions and the ballistic context of the trauma guide the treatment of GIU. When the ureteric lesion is short and associated lesions are limited, the continuity of the urinary tract can be restored after debridement of the extremities by end-to-end anastomosis for the upper 2/3 and direct vesical reimplantation or into a psoas bladder for the lower 1/3. Drainage is ensured either by a bladder catheter or by a double J stent, for a minimal duration of 3 weeks. When there is a defect of the upper two-thirds of the ureter, mobilization of the kidney and its pedicle or transureteroureterostomy may be required. Urinary diversion by nephrostomy or in situ ureterostomy is indicated when the haemodynamic state is unstable and the associated lesions are very septic or in the presence of multiple lesions. Extensive contusion of the ureteric wall must be intubated to prevent fistula formation due to necrosis. Nephrectomy should be avoided in these patients with a mean age of 27 years.

Adult↗
PubMed1996

[Abdominal gunshot wounds. Ballistic data and practical management].

The mortality from abdominal gunshot wounds remains high, either in civilian or military cases. The severity factors of these wounds include bullet calibre and energy transfer of the missile. This paper studies some of the ballistics features of abdominal gunshot wounds. Practical guidelines are inferred concerning diagnosis and treatment of these wounds.

Abdominal Injuries↗
PubMed1994

[Spinal cord injuries caused by extraspinal gunshot. A historical, experimental and therapeutic approach].

A careful study of all clinical observations reported by various authors during one century teaches us that spinal cord wounds caused by a missile path away from the spine have always had vague and mysterious mechanisms. We have simulate shots near the cervical spine included in gelatin and we have shot at pigs weighing 100 kilograms, previously anaesthetized and bio-instrumented according to J. Breteau methodology. So, we have been able to reproduce medullary wounds by shooting in the nape of the neck, away from the cervical spine. The knowledge of all mechanisms of balistic wounds, the analysis of the results obtained and a histological examination of wounded medulla leads us to the conclusion that this type of medullary wound distance from the spinal cord, is not specific and that, in fact, the missile causes an ordinary medullary contusion. While waiting for forthcoming medicinal progress, a management of treatment is suggested.

Animals↗
PubMed1993

[Lipoblastic meningioma. An uncommon benign tumor].

Often mentioned and not much documented, the lipoblastic meningioma is an unusual extra-axial benign tumor. It has spontaneously hypodensity in CT and appears with a high signal in MRI in T1-weighted sequence. Its vascularisation is rich and shows a strong contrast intake. Its resection is known as easy and its prognosis is excellent. The authors report here the observation of a 65 year old women having a lipoblastic meningioma. Literature is gone through and differential diagnoses are considered.

Aged↗
PubMed1991

[The impossible compromise. Apropos of a paper on ballistic injuries by Messrs. Cooper and Ryan].

This paper analyzes a publication of wound ballistic from MM. Cooper and Ryan published in British Journal of Surgery 1990, vol. 77 June pp. 606-610 which call "Interaction of penetrating missiles with tissues: some common misapprehensions and implications for wound management". MM. Cooper and Ryan describe interaction of penetrating missiles with tissues, they denounce that they call common misapprehensions in wound ballistic and they try to reconcile engineers works and clinical observations. As a result of this synthesis, a management of war injuries is recommended. Authors of this present paper do a methodical analysis of the British publication and denounce: 1. the experimental method and the "energy-transfer" concept; 2. two contradictories and irreconcilable doctrines promulgated in wound ballistic world which are in one hand supporters of 5.56 bullets shock wave giving distant wounds and iatrogenic mutilations, on the other hand, supporter of wounds treatment without any need to know the weapon; 3. differences between wounds of war and peacetime is sometime more theoretical than real and may give the place to the concept of circumstances surgery.

Arteries↗
PubMed1990

[War injuries of the thorax. Aggressors and wound balistics].

War chest wounds are very common, but wound balistic notions are not known of physicians. Different threats are being listed, and we might retain the important rate of shrapnels wounds. Concerning the bullet behavior in soft tissue, one can discern full jacketed war bullets which may tumble after a variable "neck", and non jacketed missiles which cause wound through "mushrooming" and/or fragmentation effect. Buckshot wounds obey the rule of "all or none". Body reactions, particularly the clash with a hard material like bone, may overturn everything described in soft tissues. Every kind of possible chest wounds are analyzed from a ballistic point of view. We insist on the effects of so called terrible high velocity little bullets which do not wound because of an "explosive" shock wave, but with a fragmentation effect. The treatment sums up to the advice of good common sense which has had such a good effect on our masters.

Blast Injuries↗
PubMed1989

[MRI: projectiles, bullets and counter-indications].

The authors present an overview of contraindications of MRI studies with bullets and projectiles. All shell splinters are ferromagnetic. There is a very large variety of bullets and their study cannot be exhaustive. In addition, same bullets of different series can be or not ferro-magnetic. Therefore, all projectiles must be considered as ferromagnetic until evidence of the contrary is found.

Ferric Compounds↗
PubMed1989

[Ballistic approach in head injuries caused by missiles].

If the missile head injury treatment is relatively well codified, wound ballistic, on the other hand, is not well known of neurosurgeons. Different means of study and tissue simulants are being listed. In face of numerous contradictory results, we shall only retain the M.L. Fackler method with 10% gelatin. Experimental results will depend on: 1. Missile parameters. For instance, in soft homogeneous tissue, one can discern shells with an uncertain path, full jacketed bullets which tumble after a variable "neck", and non jacketed missiles which cause wound through "mushrooming" and/or fragmentation effect. Buckshot wounds obey the rule "all or none". 2. Body reactions, particularly the clash with a hard material like bone, which can overturn everything described in soft tissues. These wound ballistic notions have lead us to formulate two pathogenic hypothesizes, allowing us to understand sometime case reports which had first seemed paradoxical: the brain structure, enclosed in the skull will not able to survive any major temporary cavity, the more or less deep missile pathway through the skull will be very different according to the type and energy of the missile, and to the hardness of pierced bone.

Craniocerebral Trauma↗
PubMed1987

[Early syringomyelia following benign cervical injury. Contribution of postoperative MRI].

The authors show an observation of a post traumatic syringomyelia syndrome which gradually developed a few months after a cervical sprain. The diagnosis has been mentioned after the discovery of a "big medulla" with myelography and computed tomography. The presence of a cervical cystic cavity with viscous liquid has been confirmed by surgery. A syringosubarachnoïd shunt has been carried out with excellent post operative results as the patient has recovered all his sensory and motor functions. For the pathogenic hypothesis mention is made of a small subclinic early hematomyelia which then develops on its own to form a genuine syringomyelic cavity. The authors emphasize the future interest of M.R.I. for the pathogenic diagnosis as well for the post operative effects.

Adult↗
PubMed1987

[Combination of traumatic vascular and neural lesions of the limbs. Surgical approach. Apropos of 10 cases].

Ten cases of limb injuries including vascular and nervous lesions are reported. After pointing out the modalities of diagnosis, the authors describe the surgical technic: vascular management first, and then nervous repair. After a six months to three years follow-up, among eight cases, the vascular repair is successful every time, and the nervous repair five times. Although each technic is usually easy, the association of both lesions needs the collaboration of multidisciplinary surgical teams.

Adult↗