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Biomedical subjects

Laurent Brouchet

Publications and source records attributed to Laurent Brouchet.

10 recordsLinked to original sources

Recurrent hyperparathyroidism: A sixth mediastinal parathyroid gland.

We present the case of a 71-year-old woman with recurrent hyperparathyroidism. She underwent first a subtotal resection of the parathyroid glands associated with subtotal thyroidectomy in the setting of primary hyperparathyroidism and multi nodular thyroid. Pathologic findings were consistent with hyperplasia and demonstrated a fifth parathyroid gland in the thyroid. Two years later, the patient presented recurrent hyperparathyroidism associated with terminal renal insufficiency, fusion of Sesta Mibi scintigraphy and CT scan demonstrated a sixth mediastinal parathyroid gland in the aorto pulmonary window. Despite videomediastinoscopic attempts, resection was performed through manubriotomy approach. Pathologic findings demonstrated a parathyroid adenoma.

Adenoma↗

Pulmonary angiomyolipoma.

Extrarenal angiomyolipoma are benign lesions that have rarely been described in the thorax. We present the clinical, radiographic, and pathologic findings of a pulmonary angiomyolipoma in a 63-year-old woman who had no diagnosis of tuberous sclerosis or lymphangioleiomyomatosis. We believe that this report is one of the first descriptions of angiomyolipoma of the lung.

Angiomyolipoma↗

Essential role of bone marrow fibroblast growth factor-2 in the effect of estradiol on reendothelialization and endothelial progenitor cell mobilization.

17beta-Estradiol (E2) accelerates reendothelialization and increases the number of circulating endothelial progenitor cells (EPCs), but whether fibroblast growth factor-2 (FGF2) is involved in these processes remains unknown. Here we explored the role of FGF2 in the effect of E2 on reendothelialization and EPC levels in a mouse model. As previously reported, E2 increased both the velocity of reendothelialization and the number of circulating EPCs in ovariectomized wild-type (Fgf2+/+) mice. In contrast, the effect of E2 on both parameters was abolished in FGF2-deficient mice (Fgf2-/-), demonstrating that FGF2 is absolutely required for these effects of E2. To test the implication of medullary and extramedullary FGF2, we developed chimeric mice by grafting Fgf2-/- bone marrow to Fgf2+/+ [Fgf2-/- bone marrow (BM) = > Fgf2+/+] mice and observed that the effect of E2 on both reendothelialization and EPC levels was abolished. In contrast, both effects of E2 in Fgf2+/+BM = >Fgf2-/- mice were similar to those observed in Fgf2+/+ mice, demonstrating that only BM-derived, but not extramedullary, FGF2 is required for both effects. Interestingly, E2 was found to markedly increase both FGF2(lmw) and FGF2(hmw) in bone marrow. In conclusion, FGF2, specifically medullary FGF2, is necessary and sufficient to mediate the accelerative effect of E2 on both reendothelialization and EPC mobilization.

Animals↗

The atheroprotective effect of 17beta-estradiol depends on complex interactions in adaptive immunity.

Estradiol prevents fatty streak formation in chow-fed atherosclerosis-prone apolipoprotein E (ApoE)-deficient mice. We previously reported that fatty streak development of immunodeficient ApoE(-/-)/recombination activating gene 2 (RAG-2(-/-)) double-deficient mice was insensitive to estradiol. In the present work, we demonstrate that the reconstitution of ApoE(-/-)/RAG-2(-/-) with bone marrow from immunocompetent ApoE(-/-)/RAG-2(+/+) mice restores the protective effect of estradiol on fatty streak constitution. We extended this demonstration to the model of low-density lipoprotein receptor-deficient mice, establishing the obligatory role of mature lymphocytes in this process. We then investigated whether the protective effect of estradiol was mediated by a specific lymphocyte subpopulation by studying the hormonal effect on fatty streak constitution in recently developed models of ApoE(-/-) mice deficient in selective T-lymphocyte subsets (either TCRalphabeta+, CD4+, CD8+, or TCRgammadelta+ lymphocytes) or B lymphocytes. In all these specifically immunodeficient mice, estradiol administration to ovariectomized mice conferred protection as in immunocompetent ApoE(-/-) mice, clearly demonstrating that no single lymphocyte subpopulation was specifically required for this effect. These results point to additional lymphocyte-dependent mechanisms such as modulating the interactions among lymphocytes and between lymphocytes and endothelial and/or antigen-presenting cells.

Animals↗

Improvement after lung volume reduction surgery: a role for inspiratory muscle adaptation.

In severe emphysema, lung volume reduction surgery (LVRS) can improve lung function and exercise tolerance. The maximal changes of forced expiratory volume in 1s (FEV(1)) and lung volume occur early after surgery, whereas maximal improvement of exercise tolerance occurs later. We tested the hypothesis that secondary adaptation of inspiratory muscles could explain this delayed clinical improvement. In that purpose, we evaluated nine consecutive patients before LVRS and up to 9 months post-operatively. Six weeks after LVRS, we observed an increase in FEV(1) and 6 min walk distance (6MWD). The gain in sniff nasal inspiratory pressure (SNIP) was inversely proportional to lung volume loss. Values of FEV(1) and lung volume were maintained throughout follow-up whereas SNIP values significantly increased from 6 weeks to 6 months post-LVRS. In the meantime, we observed an increase in 6MWD correlated with the SNIP increase. This suggests that in patients undergoing LVRS, early improvement of SNIP is proportional to decrease in lung volume whereas the further delayed improvement may be due, at least in part, to adaptation of the inspiratory muscles.

Adult↗

Deleting TCR alpha beta+ or CD4+ T lymphocytes leads to opposite effects on site-specific atherosclerosis in female apolipoprotein E-deficient mice.

Recent studies have demonstrated the importance of lymphocytes, especially CD4(+) T cells, in early lesions of atherosclerosis in hypercholesterolemic mice. However, the role of other T cell subpopulations, like CD8(+) T cells or TCR gamma delta T lymphocytes, is not yet clear. We have therefore generated apolipoprotein E-deficient mice genetically deficient in specific T lymphocyte subpopulations and measured atherosclerotic lesions in the aortic sinus and en face whole aorta preparation at 18 weeks and at 1 year of age. Whereas TCR gamma delta(+) T lymphocytes appeared to play a modest role, TCR alpha beta(+) T lymphocytes played a major role as their deficiency significantly prevented early and late atherosclerosis at all arterial sites. However, neither CD4(+) nor CD8(+) T cells induced any significant decrease of the lesions at the aortic sinus, suggesting that compensatory proatherogenic mechanisms are operating at this site. Interestingly, the absence of CD4(+) T cells led to a dramatic increase in early lesion abundance at the level of the descending thoracic and abdominal aorta, which was still obvious at 1 year. In conclusion, whereas the TCR alpha beta(+) lymphocyte subset in its whole contribute to aggravate both early and late atherosclerosis, the CD4(+) T subpopulation appears to be critically protective at the level of the lower part of the aorta.

Animals↗

Complete tracheal rupture after a failed suicide attempt.

Tracheal rupture is life-threatening and its management poses a considerable challenge to both anesthesiologists and surgeons. We report the case of a 44-year-old patient with a complete tracheal rupture after a failed suicide attempt by hanging. A rare bilateral injury of the laryngeal nerves was associated. An original tracheal intubation was performed using the video unit for thoracoscopy. The severity of the lesions required the placement of a tracheostomy cannula after the tracheal repair. The postoperative course was uneventful. The patient was discharged on the 12th day, with a remaining moderate dysphonia.

Adult↗

Type-A acute aortic dissection: combined operation plus stent management.

When the port of entry of acute type-A aortic dissection is at the level of the horizontal portion of the aortic arch, the latter should be replaced by a prosthesis. To avoid performing this difficult procedure in an emergency situation, we place a stent in the aortic arch. Then we replace the ascending aorta by a prosthesis.

Aged↗

Treatment of a fistula at the distal anastomosis after Bentall operation with endoluminal covered stent.

A 25-year-old Marfan patient was operated on for an acute type A aortic dissection that was complicated twice by false aneurysms at the distal suture line. At the third episode a covered endoprosthesis was inserted in the ascending aorta between the coronary ostia and the inominate artery. The postoperative course was uneventful and a control computed tomographic scan showed complete occlusion of the false aneurysm. This attractive technique should be considered versus an open-heart operation in selected patients.

Adult↗