Endocannabinoids regulate adipokine production and the immune balance of omental adipose tissue in human obesity.

OBJECTIVES: (1) To investigate whether modulation of the cannabinoid type 1 receptor (CB1R) directly regulates the production of adiponectin (ApN) and other adipokines in omental adipose tissue (OAT) of obese subjects, (2) to establish in which cellular fraction of OAT the effects of CB1R blockade take place and (3) to unravel the underlying mechanisms. SUBJECTS AND METHODS: OAT was obtained from 30 obese subjects (body mass index: 40.6±1.3 kg m(-2)) undergoing abdominal surgery. Primary cultures of explants or of freshly isolated adipocytes or stromal-vascular cells (SVCs) were used. RESULTS: In OAT explants, the CB1R blocker Rimonabant upregulated ApN gene expression. mRNA abundance of omentin that exhibits insulin-sensitizing properties was upregulated as well. Conversely, mRNA levels of two pro-inflammatory cytokines, macrophage inflammatory protein (MIP)-1ß and interleukin (IL)-7 were downregulated. We next examined where these effects took place within OAT. CB1R expression was similar in both cellular fractions. In isolated mature adipocytes, blockade of CB1R reproduced the increase of ApN mRNA and the decrease of IL-7 mRNA, while inducing a rise of ApN secretion into the medium. In isolated SVC, gene expression of omentin, which is restricted to this fraction, was augmented, while that of MIP-1ß was diminished. Finally, we deciphered the mechanisms leading to ApN regulation by the endocannabinoid system (ES). We first established that ApN regulation was actually mediated by the CB1R: ApN gene expression was upregulated by Rimonabant and downregulated by the CB1R agonist arachidonyl-2-chloroethylamide (ACEA). Upregulation of ApN by Rimonabant was unaltered by inhibiting cAMP production. However, downregulation of ApN by ACEA was fully reversed by an inhibitor of p38 mitogen-activated protein kinase (p38MAPK) and ACEA increased p38MAPK phosphorylation. CONCLUSIONS: Blockade of CB1R attenuates the inflammatory state in both cellular fractions of OAT either by increasing ApN and omentin production or by decreasing mRNAs of MIP-1ß and IL-7. ApN regulation by the ES partly involves p38MAPK.

Adipokines oversecreted by omental adipose tissue in human obesity.

Central-omental obesity plays a causative role in the pathogenesis of the metabolic syndrome. Adipokines are involved in the pathogenesis of this syndrome. However, adipokines secreted by omental adipose tissue (OAT) are still poorly characterized in human obesity. Therefore, we searched for novel adipokines abnormally secreted by OAT in obesity and examined their relationships with some features of metabolic syndrome and the respective contribution of adipocytes vs. stromal-vascular cells. OAT from obese and nonobese men was fractionated into adipocytes and SV cells, which were then cultured. Medium was screened by medium-scale protein arrays and ELISAs. Adipokine mRNA levels were measured by real-time RT-qPCR. We detected 16 cytokines secreted by each cellular fraction of lean and obese subjects. Of the 16 cytokines, six adipokines were newly identified as secretory products of OAT, which were dysregulated in obesity: three chemokines (growth-related oncogen factor, RANTES, macrophage inflammatory protein-1beta), one interleukin (IL-7), one tissue inhibitor of metalloproteinases (TIMP-1), and one growth factor (thrombopoietin). Their secretion and expression were enhanced in obesity, with a relatively similar contribution of the two fractions. The higher proportion of macrophages and endothelial cells in obesity may contribute to this enhanced production as well as changes in intrinsic properties of hypertrophied adipocytes. Accordingly, mRNA concentrations of most of these adipokines increased during adipocyte differentiation. Eventually, expression of the investigated adipokines did correlate with several features of the metabolic syndrome. In conclusion, six adipokines were newly identified as oversecreted by OAT in obesity. These adipokines may link obesity to its cardiovascular or metabolic comorbidities.

Epstein-Barr virus-associated lymphoproliferative disease occurring in a patient with sarcoidosis treated by methotrexate and methylprednisolone.

We describe the case of a 51-yr-old man with systemic sarcoidosis, complicated by the occurrence of a lymphoproliferative disease following a 36-month (duration) immunosuppressive treatment with methotrexate (MTX) and methylprednisolone. Four years after the onset of sarcoidosis, the patient presented a large necrotizing anal fistula. Pathological examination of this lesion showed a diffuse polymorphic infiltrate containing large Epstein-Barr virus (EBV)-positive lymphoid cells associated with areas of necrosis, all features similar to classical B-cell lymphoproliferative disorders occurring in immunosuppressed solid-organ recipients. MTX has been recently implicated in the development of lymphoproliferative disease in connective tissue diseases. This case supports the hypothesis that immunosuppression therapy may contribute to an increased risk for the development of EBV-associated lymphoproliferative disorders in patients suffering from sarcoidosis.

Secretion of adiponectin and regulation of apM1 gene expression in human visceral adipose tissue.

Adiponectin (ApN) is thought to play a major role in the pathogenesis of the Metabolic Syndrome. Production of ApN and regulation of its related gene (apM1) have not yet been studied in human visceral adipose tissue. ApN was mainly associated with adipocyte membranes and abundantly secreted in medium from isolated adipocytes. apM1 gene expression, restricted to the adipocyte fraction of adipose tissue, decreased spontaneously when adipose explants were cultured in basal medium for 24 h while the expression of other adipose genes barely changed (PPARgamma, GAPDH) or increased (PAI-1). Unexpectedly, the fall of apM1 mRNA was prevented by the addition of actinomycin D, an inhibitor of transcription, or cycloheximide, an inhibitor of protein synthesis, and by reducing the amount of adipose tissue cultured per dish, thereby suggesting that a newly synthesized factor released by adipose tissue destabilizes apM1 mRNA. apM1 gene expression was also negatively regulated by glucocorticoids and positively by insulin and IGF-1. This regulation could contribute to the decreased apM1/ApN levels in insulin-resistant patients with obesity and the Metabolic Syndrome.

Follow-up after curative surgery for colorectal cancer.

Approximately 1 in 3 colorectal patients treated by surgery with curative intent will develop cancer recurrence, and most of them will die from disseminated disease. Post-operative follow-up aims at improving these ominous figures. Any strategy is justified as far as it influences evolution: global survival, disease-free period, quality of life. The value of follow-up for patients remains controversial. The literature review suggests that more intensive follow-ups lead to an increased number of reoperations, a more aggressive oncological approach in non resectable cases, provide data for an efficient quality control and have a major cost impact. Surveillance is appreciated by the patients who are confident in the efficacy of such policies. On the other hand, the benefit on the outcome of the patients is not formally established. Outcome might depend on tumoural characteristics rather than on the moment of recurrence detection. Not all schedules are alike, and CEA determination is required. Including all patients in intensive programs is not evidence-based medicine and is highly cost ineffective. Follow-ups must be tailored to individual characteristics. The most intensive ones are dedicated to the patients with the highest risk of treatable recurrence: high risk patients (tumour site and stage), able and willing to undergo reoperation (age, general condition,...). Research should try to determine curability tumoural factors (genetic tumour factors). In the meantime, and for the other patients, the most effective follow-ups could be programs in which only a few tests are routinely used: referential colonoscopy, history and physical examination, CEA determination and a rectoscopy for rectal cancers.

Hormonal control of plasminogen activator inhibitor-1 gene expression and production in human adipose tissue: stimulation by glucocorticoids and inhibition by catecholamines.

Plasma levels of type 1 plasminogen activator inhibitor (PAI-1), a risk factor for cardiovascular disease, are elevated in obese subjects, especially those with omental fat accumulation. We investigated the hormonal control of PAI-1 gene expression and secretion in cultured human adipose tissue. We more particularly focused on the effects of glucocorticoids, insulin, cAMP, and catecholamines in explants from the omental region. The addition of dexamethasone to the culture medium increased PAI-1 secretion in a time-dependent manner for up to 24 h. The stimulation by the glucocorticoid was preceded by a 2-fold rise in PAI-1 messenger ribonucleic acid levels between 4-8 h of culture. The effectiveness of the glucocorticoid was concentration dependent, with a half-maximal effect within a physiological range. This stimulation was also observed in sc fat, but dexamethasone-stimulated as well as basal PAI-1 secretion rates were always higher in omental fat. Unlike dexamethasone, 24-h insulin did not modify PAI-1 secretion while accelerating glucose consumption. In contrast, 24-h cAMP inhibited PAI-1 gene expression and protein production under basal conditions and in the presence of dexamethasone. This inhibition was already detectable after 1 h and was maximal after 4 h at the level of gene expression. It occurred in both omental and sc adipose tissues. Importantly, epinephrine dose dependently inhibited PAI-1 parameters, an effect that was reproduced by isoproterenol. Dexamethasone- and cAMP-induced changes in PAI-1 messenger ribonucleic acid abundance were similar in explants and isolated fat cells. In isolated stromal-vascular cells, only dexamethasone was effective. In conclusion, we provide evidence for a reciprocal regulation of PAI-1 by dexamethasone (positive effector) and cAMP/catecholamines (negative effectors) in cultured human adipose tissue. The stimulation by glucocorticoids could contribute to enhanced production of PAI-1 by adipose tissue and high plasma levels of PAI-1 associated with central obesity and thereby be a link between this disorder and cardiovascular disease. Impaired inhibition by catecholamines could also contribute, as in vivo adipose tissue responses to these hormones are usually blunted in obese individuals.

Colorectal villous tumors accuracy of the preoperative biopsies.

This study was undertaken to assess the reliability of the endoscopic biopsies in the evaluation of colorectal villous tumors (CRVT). In 163 consecutive patients referred for surgical treatment of CRVT, preoperative evaluation had been routinely done by colonoscopy and multiple biopsies. Tumors were classified in 3 groups: low grade tumors, high grade tumors and adenocarcinomas. Infiltration in depth was staged on the postoperative specimens according to the Dukes-Aster-Coller's classification. All the tumors were completely resected by surgery and definitive pathological diagnosis was established. An exact correlation between the pre- and postoperative staging was observed in 48% of the cases. Accuracy averaged 54% in the group-by-group comparison, with an overstaging rate of 6.7%, and an understaging rate of 39%. The incidence of adenocarcinomas was 22% in the group with clearly benign preoperative biopsies and 50% in the other cases. There were significantly more B2 and C tumors among the patients referred after 3 or more endoscopic attempts (33%) than after one or two sessions (10%) (p < 0.0003). We confirm that in spite of multiple endoscopic biopsies, only a complete resection permits an exact staging and an appropriate therapeutic choice.

Surgery in Belgium.

To fully understand the present state of surgery in Belgium, it is necessary to know the structure of the Belgian State, the type of education, the statutory health insurance system, and the professional bodies representing surgeons. One of the most important problems is the excessive number of physicians, which recently led to the establishment of limits on the number of candidates receiving medical certification. Surgical training modalities are described and the results of a retrospective study concerning the quality of training are detailed. The continuing medical education and peer-review system (accreditation) is presented.

Subacute ischaemic proctitis: a rare condition requiring extensive rectal surgery.

Subacute ischaemic proctitis is a rare condition. We describe the case of a 60-year-old male patient who developed, after aortic aneurysm repair, a transient ischaemic colitis that totally healed without sequelae. He eventually developed symptoms of severe proctitis. Investigations identified a stenosis of the mid rectum, while the upper rectum was inflammatory. On angiogram, there was a poor blood flow through the Riolan's arcade and a stenosis of the proximal aorto-graft anastomosis. Diagnosis of subacute ischaemic proctitis due to poor blood supply through the internal iliac arteries was made. Anti-inflammatory drugs and dilations were inefficient. A subtotal proctectomy with low colorectal anastomosis was required. On pathological specimen, the lesions were strongly suggestive of an ischaemic process. The patient had an excellent recovery and was asymptomatic 8 months after the operation.

Familial adenomatous polyposis associated with multiple adrenal adenomas in a patient with a rare 3' APC mutation.

Familial adenomatous polyposis (FAP) is characterised by hundreds of colorectal adenomas. Endocrine neoplasms have occasionally been reported, as have gastric polyps, which are usually hamartomatous in the fundus of the stomach and adenomatous in the antrum. A 57 year old man with colorectal, gastric, and periampullary adenomatous polyposis, in association with three bilateral adrenocortical adenomas, is presented. Mutation screening showed a 5960delA germline mutation in the adenomatous polyposis coli (APC) gene predicted to lead to a premature stop codon. This mutation was found in three of the four children of the patient. Western blot analysis of a lymphoblastoid cell line derived from the patient failed to detect any truncated APC polypeptide. This rare 3' mutation is responsible for an unusually complex and late onset phenotype of FAP.

Early feeding after colorectal surgery. Preliminary results.

Thirty three patients were placed under early oral feeding after elective colorectal surgery. There were 15 male and 18 female patients, mean age: 52 years. Nasogastric tube was removed as soon as they were widely awake, or on the morning following the afternoon operations. Oral feeding was resumed 4 hours later, and the first meal consisted in a slight solid meal. There was no postoperative mortality or significant morbidity. Liquid and solid oral intakes were resumed 18 and 24 hours respectively after the operation. Tolerance was perfect in 22 patients (66%), good (slight complaints) in 16%, and was considered as fair or bad in the last six cases. Intestinal transit was observed after a median period of 2 days. Tube insertion rate was 12%. No adverse effect on the anastomoses was noted. Data from the literature confirm that early feeding is tolerable and safe after open colorectal surgery. More patients should be included in this protocol to take benefit of the physiological effects of early oral feeding.

Multihormonal control of ob gene expression and leptin secretion from cultured human visceral adipose tissue: increased responsiveness to glucocorticoids in obesity.

The direct role of hormones on leptin synthesis has not yet been studied in cultured adipose cells or tissue from lean and obese subjects. Moreover, this hormonal regulation has never been addressed in human visceral fat, although this site plays a determinant role in obesity-linked disorders. In this study, we investigated the hormonal control of ob expression and leptin production in cultured visceral adipose tissue from lean and obese subjects. We more particularly focused on the interactions between glucocorticoids and insulin. We also briefly tackled the role of cAMP, which is still unknown in man. Visceral (and subcutaneous) adipose tissues from eight obese (body mass index, 41 +/- 2 kg/m2) and nine nonobese (24 +/- 1 kg/m2) subjects were sampled during elective abdominal surgery, and explants were cultured for up to 48 h in MEM. The addition of dexamethasone to the medium increased ob gene expression and leptin secretion in a time-dependent manner. Forty-eight hours after dexamethasone (50 nmol/L) addition, the cumulative integrated ob messenger ribonucleic acid (mRNA) and leptin responses were, respectively, approximately 5- and 4-fold higher in obese than in lean subjects. These responses closely correlated with the body mass index. The stimulatory effect of the glucocorticoid was also concentration dependent (EC50 = approximately 10 nmol/L). Although the maximal response was higher in obese than in lean subjects, the EC50 values were roughly similar in both groups. Unlike dexamethasone, insulin had no direct stimulatory effect on ob gene expression and leptin secretion. Singularly, insulin even inhibited the dexamethasone-induced rise in ob mRNA and leptin release. This inhibition was observed in both lean and obese subjects, whereas the expected stimulation of insulin on glucose metabolism and the accumulation of mRNA species for the insulin-sensitive transporter GLUT4 and glyceraldehyde-3-phosphate dehydrogenase occurred in lean patients only. This inhibitory effect was already detectable at 10 nmol/L insulin and was also observed in subcutaneous fat. Although a lowering of intracellular cAMP concentrations is involved in some of the effects of insulin on adipose tissue, this cannot account for the present finding, because the addition of cAMP to the medium also decreased ob mRNA and leptin secretion (regardless of whether dexamethasone was present). In conclusion, glucocorticoids, at physiological concentrations, stimulated leptin secretion by enhancing the pretranslational machinery in human visceral fat. This effect was more pronounced in obese subjects due to a greater responsiveness of the ob gene and could contribute to the metabolic abnormalities associated with central obesity by para/endocrine actions of hyperleptinemia on adipocytes and liver. Unlike dexamethasone, insulin had no direct stimulatory effect on ob gene expression and leptin secretion, and even prevented the positive response to dexamethasone by a cAMP-independent mechanism that remained functional despite insulin resistance.

Inadequate detection of accessory spleens and splenosis with laparoscopic splenectomy. A shortcoming of the laparoscopic approach in hematologic diseases.

BACKGROUND: The ultimate goal of surgery for hematological disorders is the complete removal of both the spleen and accessory spleens in order to avoid recurrence of the disease. Whereas splenectomy by open surgery provides excellent results, the validity of laparoscopic splenectomy in this regard remains unknown. OBJECTIVE: The purpose of this study was to evaluate the detection of accessory spleens during laparoscopic splenectomy for hematologic diseases. METHODS: We therefore evaluated the pre-, intra-, and postoperative detection of accessory spleens in a consecutive series of 18 patients treated by elective laparoscopic splenectomy for hematological diseases by using computed tomography (CT) and denatured red blood cell scintigraphy (DRBCS). RESULTS: Preoperative CT, DRBCS, and laparoscopic exploration detected 25%, 25%, and 75% of accessory spleens, respectively. At time of laparoscopy, 16 accessory spleens were detected in seven of the 18 patients (41%). In two patients (11%), laparoscopic exploration failed to detect accessory spleens, whereas preoperative CT (one case) and DRBCS (one case) did reveal them. Postoperatively, during a mean follow-up of 28 months (median, 24; range, 12-44 months), nine patients (50%) showed persistence of splenic tissue by DRBCS, and three of them had signs of disease recurrence. CONCLUSIONS: This prospective clinical study suggests that elective laparoscopic surgery for hematological diseases does not allow complete detection of accessory spleens. Moreover, after such a laparoscopic approach, residual splenic tissue is detectable in half of the patients during the follow-up.

[Preoperative evaluation of cancers of the rectum]. / Bilan pré-opératoire du cancer du rectum.

The diagnosis of colorectal cancer must be considered in the presence of suggestive symptoms and must be endoscopy. Assessment of operability, including chest x-ray, is completed by CEA determination and x-rays of the colon, looking for a synchronous lesion. Complementary assessments must answer 3 questions: what operation needs to be performed, is any preoperative adjuvant treatment indicated, do any prognostic factors need to be identified before the operation. The treatment of cancer of the colon is now clearly defined; intraoperative hepatic ultrasonography and histological examination of the resection specimen provide all of the necessary data in the majority of the cases. In the presence of a cancer of the rectum, various therapeutic alternatives are available according to the site and stage of the tumour. The complementary assessment includes biopsy to confirm the malignant nature of the lesion, and measurement of the distance of the lower pole from the anal margin (digital rectal examination, endoscopy). A more precise preoperative staging by ultrasonography, computed axial tomography or magnetic resonance is required when the clinician considers that the invasive nature of the lesion justifies preoperative radiotherapy. This precise staging is fully justified in the presence of a small rectal tumour amenable to local resection. Although infiltration of the rectal wall is now very clearly defined, formal identification of metastatic lymphadenopathy still remains hazardous. Finally, the search for distant metastases by invasive and/or expensive techniques is indicated when looking for contraindications to surgery (high-risk patients, surgery for recurrence and metastases). In other cases, the presence of metastases does not contraindicate a palliative colonic resection and intraoperative exploration allows reliable identification of any liver metastasis.