Benjamin Castel

Paris Diderot University, Lutetia Parisorum, Île-de-France, France

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Publications (24)91.84 Total impact

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    ABSTRACT: Obesity-associated inflammation contributes to the development of metabolic diseases. While brite adipocytes have been shown to ameliorate metabolic parameters in rodents, their origin and differentiation remain to be characterized in humans. Native CD45-/CD34+/CD31- cells have been previously described as human adipocyte progenitors. Using two additional cell surface markers, MSCA1 (tissue non-specific alkaline phosphatase), and CD271 (nerve growth factor receptor), we are able to partition the CD45-/CD34+/CD31- cell population into three subsets. We establish serum-free culture conditions without cell expansion to promote either white/brite adipogenesis using rosiglitazone or Bone Morphogenetic Protein 7 (BMP7), or specifically brite adipogenesis using 3-Isobuthyl-1-Methylxanthine. We demonstrate that adipogenesis leads to an increase of MSCA1 activity, expression of white/brite adipocyte-related genes and mitochondriogenesis. Using pharmacological inhibition and gene silencing approaches, we show that MSCA1 activity is required for triglyceride accumulation and for the expression of white/brite-related genes in human cells. Moreover, native immunoselected MSCA1+ cells exhibit brite precursor characteristics and the highest adipogenic potential of the three progenitor subsets. Finally, we provided evidence that MSCA1+ white/brite precursors accumulate with obesity in subcutaneous adipose tissue (sAT) and that local BMP7 and inflammation regulate brite adipogenesis by modulating MSCA1 in human sAT. The accumulation of MSCA1+ white/brite precursors in sAT with obesity may reveal a blockade of their differentiation by immune cells, suggesting that local inflammation contributes to metabolic disorders through impairment of white/brite adipogenesis. This article is protected by copyright. All rights reserved.
    Stem Cells 12/2014; 33(4). DOI:10.1002/stem.1916 · 6.52 Impact Factor
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    ABSTRACT: Although the risk of cholelithiasis (CL) increases in patients after Roux-en-Y gastric bypass (RYGB), no prospective study has yet assessed the incidence of CL after sleeve gastrectomy (SG). To compare, prospectively, the incidence and predictive factors for CL after both procedures. A postoperative abdominal ultrasound follow-up was proposed to all patients with an intact gallbladder and who underwent RYGB or SG in Hôpital Louis Mourier from 2008 onward. At least one ultrasound was performed on one hundred and sixty patients between 6 and 12 months postsurgery, 43 after SG and 117 after RYGB. Age, gender, initial body-mass index, co-morbidities were similar in both groups. Weight loss (WL) at 6 months was significantly lower after SG than after RYGB (26.9±9.2 and 31.3±7.5 kg, respectively = .001). The incidences of CL after SG and RYGB were similar (28% versus 34% respectively, P = .57). Most cases of CL occurred in the first year post surgery. During the follow-up, 12% and 13% of patients who underwent SG and RYGB, respectively, became symptomatic. WL of>30 kg at 6 months was a risk factor for CL after bariatric surgery, but we did not find any preoperative predictive factor for gallstone formation. Despite lower WL after SG, the incidence of CL after SG and RYGB was similar at 2 years. Our results suggest that rapid WL is the main element leading to gallstone formation after both procedures. Copyright © 2015 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.
    Surgery for Obesity and Related Diseases 10/2014; 11(4). DOI:10.1016/j.soard.2014.10.015 · 4.07 Impact Factor
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    ABSTRACT: To study long-term nutritional deficits based on adherence to a standardized nutritional care after gastric bypass (GBP). Long-term prospective data on nutritional complications after GBP are missing. It is not known whether severe deficiencies are prevented by standard multivitamin supplementation and what parameters are influenced by patient adherence to nutritional care. One hundred forty-four consecutive subjects from our prospective database (90% women, initial body mass index: 48 ± 15 kg/m, age: 43 ± 10 years) who underwent GBP more than 3 years before the study were assessed. Multivitamins were systematically prescribed after GBP, and additional supplements were introduced if deficiencies were recorded during follow-up. We identified a group of 66 compliant subjects who attended yearly medical visits and a group of 32 noncompliant subjects who were recalled because they had not attended any visit for more than 2 years. Weight loss was 42 ± 14 kg at 3 years or later. The number of nutritional deficits per subject was 3.2 ± 2.3 before surgery and did not significantly increase between 1 and 3 years or later after GBP (3.4 ± 2.0 and 3.5 ± 2.3, respectively). However, specific nutritional deficits occurred despite long-term multivitamin supplementation, including vitamins B1, B12, and D and iron. Noncompliant subjects had more deficits than compliant subjects (4.2 ± 1.9 vs 2.9 ± 2.0 deficits per patient, P < 0.01) and the number of deficits correlated with the time from last visit (r = 0.285, P < 0.01). Lifelong medical care is required to maintain a good nutritional status after GBP. Monitoring of nutritional parameters is necessary to add supplementation for deficits that are not prevented by multivitamin preparations.
    Annals of surgery 06/2014; 259(6):1104-10. DOI:10.1097/SLA.0000000000000249 · 8.33 Impact Factor
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    ABSTRACT: Sleeve gastrectomy (SG) is supposed to induce fewer nutritional deficiencies than gastric bypass (GBP). However, few studies have compared nutritional status after these two procedures, and the difference in weight loss (WL) between procedures may alter the results. Thus, our aim was to compare nutritional status after SG and GBP in subjects matched for postoperative weight. Forty-three subjects who underwent SG were matched for age, gender, and 6-month postoperative weight with 43 subjects who underwent GBP. Dietary intakes (DI), metabolic (MP), and nutritional parameters (NP) were recorded before and at 6 and 12 months after both procedures. Multivitamin supplements were systematically prescribed after surgery. Before surgery, BMI, DI, MP, and NP were similar between both groups. After surgery, LDL cholesterol, serum prealbumin, vitamin B12, urinary calcium, and vitamin D concentrations were lower after GBP than after SG, whereas WL and DI were similar after both procedures. However, the total number of deficiencies did not increase after surgery regardless of the procedure. In addition, we found a significant increase in liver enzymes and a greater decrease in C-reactive protein after GBP. In conclusion, during the first year after surgery, in patients with the same WL and following the same strategy of vitamin supplementation, global nutritional status was only slightly impaired after SG and GBP. However, some nutritional parameters were specifically altered after GBP, which could be related to malabsorption or other mechanisms, such as alterations in liver metabolism.
    Obesity Surgery 10/2013; 24(2). DOI:10.1007/s11695-013-1089-6 · 3.75 Impact Factor

  • Annales d Endocrinologie 09/2013; 74(4):455-456. DOI:10.1016/j.ando.2013.07.780 · 0.87 Impact Factor
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    F Simon · I Siciliano · A Gillet · B Castel · B Coffin · S Msika ·
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    ABSTRACT: Background: Laparoscopic sleeve gastrectomy has become a very frequent procedure in bariatric surgery due to its efficacy and simplicity compared to gastric bypass. Gastric staple line leak (1 to 7 % of cases) is a severe complication with a long nonstandardized treatment. The aim of this retrospective study was to examine the success and tolerance of covered stents in its management. Methods: From January 2009 to December 2011, nine patients with gastric staple line leaks after sleeve gastrectomy were treated with covered stents in our department (seven referred from other institutions). The leaks were diagnosed by CT scan and visualized during the endoscopy. Among the studied variables were operative technique, post-operative fistula diagnosis delay, stent treatment delay, and stent tolerance. In our institution, Hanarostent® (length 17 cm, diameter 18 mm; M.I. Tech, Seoul, Korea) was used and inserted under direct endoscopic control. Results: Stent treatment was successful in seven cases (78 %). Two other cases had total gastrectomy (405 and 185 days after leak diagnosis). Early stent removal (due to migration or poor tolerance) was necessary in three cases. The average stent treatment duration was of 6.4 weeks, and the average healing time was 141 days. The five patients with an early stent treatment (≤ 3 weeks after leak diagnosis) had an average healing time of 99 days versus 224 for the four others. Conclusions: Covered self-expandable stent is an effective treatment of gastric leaks after sleeve gastrectomy. Early stent treatment seems to be associated with shorter healing time.
    Obesity Surgery 01/2013; 23(5). DOI:10.1007/s11695-012-0861-3 · 3.75 Impact Factor
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    ABSTRACT: Background: Malabsorptive surgical procedures lead to deficiencies in fat-soluble vitamins. However, results concerning serum vitamin D (25OHD) after gastric bypass (GBP) are controversial. The aim of the study was to assess the influence of GBP on 25OHD and calcium metabolism. Methods: Parameters of calcium metabolism were evaluated in 202 obese subjects before and 6 months after GBP. Thirty of them were matched for age, gender, weight, skin color, and season with 30 subjects who underwent sleeve gastrectomy (SG). A multivitamin preparation that provides 200 to 500 IU vitamin D3 per day was systematically prescribed after surgery. Results: In the 202 patients after GBP, serum 25OHD significantly increased from 13.4 ± 9.1 to 22.8 ± 11.3 ng/ml (p < 0.0001), whereas parathyroid hormone (PTH) did not change. Despite a decrease in calcium intake (p < 0.0001) and urinary calcium/creatinine ratio (p = 0.015), serum calcium increased after GBP (p < 0.0001). Preoperatively, 91 % of patients had 25OHD insufficiency (< 30 ng/ml), 80% deficiency (< 20 ng/ml), and 19% secondary hyperparathyroidism (> 65 pg/ml) vs. 76, 44, and 17%, respectively, following GBP. Serum 25OHD was negatively correlated with BMI at 6 months after GBP (R = -0.299, p < 0.0001). In the two groups of 30 subjects, serum 25OHD and PTH did not differ at 6 months after GBP or SG. Conclusions: At 6 months after GBP, serum 25OHD significantly increased in subjects supplemented with multivitamins containing low doses of vitamin D. These data suggest that weight loss at 6 months after surgery has a greater influence on vitamin D status than malabsorption induced by GBP.
    Obesity Surgery 11/2012; 23(4). DOI:10.1007/s11695-012-0813-y · 3.75 Impact Factor

  • Gastroenterology 01/2011; 140(5). DOI:10.1016/S0016-5085(11)62329-9 · 16.72 Impact Factor
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    ABSTRACT: Substantial weight loss is achieved in majority of severely obese subjects undergoing laparoscopic gastric bypass (LGBP) but some fail to obtain expected results. Our aim was to identify preoperative factors that could influence weight loss (WL) 1 year after LGBP. We studied the predictive value of clinical, biological, and dietary preoperative factors on weight loss in obese patients referred for LGBP. WL was assessed according to mean absolute weight loss (AWL) and mean percent excess weight loss (%EWL) 1 year after LGBP. One hundred twenty-three subjects were included (112 women, age 42 ± 10 years; weight 127 ± 23 kg; BMI 47 ± 8 kg/m(2)). Mean AWL was 39.4 ± 10.5 kg at 1 year, corresponding to a mean %EWL of 70.5 ± 21.2%. AWL was positively correlated with initial weight, BMI, and energy intake and negatively with age, female sex, and treatment for hypertension and diabetes. %EWL was negatively correlated with initial weight, BMI, and positively correlated with triglycerides and ferritinemia. In multivariate analysis, %EWL was negatively correlated only with initial BMI (p < 0.001). AWL was positively correlated with initial BMI and male sex (both p < 0.001), and negatively correlated with protein intake (p = 0.039) and treatment for diabetes (p = 0.021), but not with biomarkers of diabetes and insulin resistance. Initial BMI appears to be a strong determinant of individual WL, but predictive factors differ when WL was expressed as %EWL or AWL. The treatment of diabetes rather than diabetes itself appears to affect WL.
    Obesity Surgery 12/2010; 20(12):1671-7. DOI:10.1007/s11695-010-0159-2 · 3.75 Impact Factor
  • S. Msika · B. Castel ·

    Journal de Chirurgie Viscerale 10/2010; 147(5). DOI:10.1016/j.jchirv.2010.08.017

  • S Msika · B Castel ·

    Journal of Visceral Surgery 10/2010; 147(5 Suppl):e47-51. DOI:10.1016/j.jviscsurg.2010.08.015 · 1.75 Impact Factor
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    ABSTRACT: Desmoplastic round small cell tumor (DRSCT) is a rare intraabdominal mesenchymal tissue neoplasm in young patients and spreads through the abdominal cavity. Its prognosis is poor despite a multimodal therapy including chemotherapy, radiotherapy, and surgical cytoreduction (CS). hyperthermic intraperitoneal chemotherapy (HIPEC) is considered as an additional strategy in the treatment of peritoneal carcinomatosis; for this reason, we planned to treat selected cases of children with DRSCT using CS and HIPEC. Peritoneal disease extension was evaluated according to Gilly classification. Surgical cytoreduction was considered as completeness of cytoreduction-0 when no macroscopic nodule was residual; HIPEC was performed according to the open technique. We described 3 cases: the 2 first cases were realized for palliative conditions and the last one was operated on with curative intent. There was no postoperative mortality. One patient was reoperated for a gallbladder perforation. There was no other complication related to HIPEC procedure. Surgical cytoreduction and HIPEC provide a local alternative approach to systemic chemotherapy in the control of microscopic peritoneal disease in DRSCT, with an acceptable morbidity, and may be considered as a potential beneficial adjuvant waiting for a more specific targeted therapy against the fusion protein.
    Journal of Pediatric Surgery 08/2010; 45(8):1617-21. DOI:10.1016/j.jpedsurg.2010.03.002 · 1.39 Impact Factor

  • Gastroenterology 05/2010; 138(5). DOI:10.1016/S0016-5085(10)61782-9 · 16.72 Impact Factor
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    ABSTRACT: The prevalence of morbid obesity is rapidly increasing worldwide. As surgery has been recognized to be the only effective treatment for morbid obesity, the number of bariatric procedure realized each year has dramatically increased. Among all the surgical options, gastric bypass in considered as the gold standard. A possible drawback of this operation is the difficult access to the excluded proximal intestinal tract and, consequently, to the biliary tract. As gallstone formation may be frequent after a rapid weight loss induced by surgery, surgeons could be frequently asked to face the need of exploration of the biliary tree after anatomical changes induced by this kind of surgery. Many technical solutions, mainly based on a combined laparoscopic and endoscopic approach, have been proposed by several authors to face this problem. We herein describe an original technique to allow endoscopic exploration of biliary tract after a laparoscopic gastric bypass based on temporary restoration of physiological digestive continuity followed by re-establishment of the Roux-en-Y loop.
    Obesity Surgery 03/2010; 20(6):791-5. DOI:10.1007/s11695-010-0115-1 · 3.75 Impact Factor

  • Gastroentérologie Clinique et Biologique 03/2009; 33(3). DOI:10.1016/S0399-8320(09)72875-1 · 1.14 Impact Factor

  • Journal de Chirurgie 05/2008; 145(3):278-83. · 0.50 Impact Factor
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    ABSTRACT: Cette observation a été présentée au 3e Congrès francophone de chirurgie digestive et hépatobiliaire, à Marne-la-Vallée, le 8 décembre 2007 lors de la séance de dossiers cliniques. Le présentateur (Docteur Justine Prost à la Denise) fait des propositions, discutées par les animateurs (Docteurs Sauvanet et Mariette) qui encouragent la salle à prendre la parole.
    Journal de Chirurgie 05/2008; 145(3):278-283. DOI:10.1016/S0021-7697(08)73760-8 · 0.50 Impact Factor
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    ABSTRACT: To review our experience of laparoscopic hyperthermic intraperitoneal chemotherapy (HIPEC) in the treatment of malignant ascites from advanced gastric cancer in order to discuss benefits, problems and possible indications. From June 2000 to May 2003 laparoscopic approach was used to perform HIPEC on five patients affected by malignant ascites secondary to unresectable peritoneal carcinomatosis of gastric origin, in order to associate the benefits of a definitive palliation of ascites with a minimal invasiveness. All patients had ascites related symptoms requiring iterative paracenteses. Intraperitoneal perfusion of mitomycin-C and cisplatin was delivered for 60-90min with an inflow temperature of 45 degrees C. Complete clinical regression of ascites and related symptoms was achieved in all the five patients treated. Intraoperative course was uneventful in all cases. Mean operative time was 181min. No postoperative deaths, related to the procedure, occurred. Only a case of delayed gastric empting was recorded as a minor postoperative complication. Laparoscopic HIPEC appears to be a safe and effective procedure to treat debilitating malignant ascites from unresectable peritoneal carcinomatosis.
    European journal of surgical oncology: the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology 03/2008; 34(2):154-8. DOI:10.1016/j.ejso.2007.05.015 · 3.01 Impact Factor
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    ABSTRACT: Most pseudoaneurysms (PsA) of the peripancreatic arteries cause direct erosion of the arterial wall from pancreatic enzymes that are usually in contact with or in a pseudocyst (PC). Rupturing is a rare and serious complication (90% mortality if untreated). We report the case of a 56-year-old patient with chronic alcoholic pancreatitis who developed a cephaloisthmic PC, complicated with a PsA of the gastroduodenal artery revealed by pain and deglobulization associated with cholestasis. After a diagnostic scan, emergency selective arteriography with coil embolization was performed. Five days later, hemorrhage recurred and a cephalic duodenopancreatectomy was performed. PsA of the gastroduodenal artery occur in the first 10 years of chronic pancreatitis. They are revealed by abdominal pains and/or gastrointestinal hemorrhage or shock from rupture. A scan with arterial reconstruction provides diagnosis. Arteriography is the most sensitive technique to locate the aneurysm and its branches and to perform selective embolization with coils. The failure rate is between 0 and 23%. Surgical treatment (elective ligation of the artery or partial pancreatic excision) should be limited to when embolisation fails and/or recurrent hemorrhage.
    Gastroentérologie Clinique et Biologique 02/2008; 32(1 Pt. 1):69-73. · 1.14 Impact Factor