Human bone marrow adipocytes block granulopoiesis through neuropilin-1-induced granulocyte colony-stimulating factor inhibition

Adipocytes are part of hematopoietic microenvironment, even though up to now in humans, their role in hematopoiesis is still questioned. We have previously shown that accumulation of fat cells in femoral bone marrow (BM) coincides with increased expression of neuropilin-1 (NP-1), while it is weakly expressed in hematopoietic iliac crest BM. Starting from this observation, we postulated that adipocytes might exert a negative effect on hematopoiesis mediated through NP-1. To test this hypothesis, we set up BM adipocytes differentiated into fibroblast-like fat cells (FLFC), which share the major characteristics of primitive unilocular fat cells, as an experimental model. As expected, FLFCs constitutively produced macrophage colony stimulating factor and induced CD34(+) differentiation into macrophages independently of cell-to-cell contact. By contrast, granulopoiesis was hampered by cell-to-cell contact but could be restored in transwell culture conditions, together with granulocyte colony stimulating factor production. Both functions were also recovered when FLFCs cultured in contact with CD34(+) cells were treated with an antibody neutralizing NP-1, which proved its critical implication in contact inhibition. An inflammatory cytokine such as interleukin-1 beta or dexamethasone modulates FLFC properties to restore granulopoiesis. Our data provide the first evidence that primary adipocytes exert regulatory functions during hematopoiesis that might be implicated in some pathological processes. Disclosure of potential conflicts of interest is found at the end of this article.

Carcinoid tumor of the appendix: A consecutive series from 1237 appendectomies

AIM: To report the experience of the CHU Sart Tilman, University of Liège, Belgium, in the management of appendiceal carcinoid tumor.

METHODS: A retrospective review of 1237 appendectomies performed in one single centre from January 2000 to May 2004, was undertaken. Analysis of demographic data, clinical presentation, histopathology, operative reports and outcome was presented.

RESULTS: Among the 1237 appendectomies, 5 appendiceal carcinoid tumors were identified (0.4%) in 4 male and 1 female patients, with a mean age of 29.2 years (range: 6-82 years). Acute appendicitis was the clinical presentation for all patients. Four patients underwent open appendectomy and one a laparoscopic procedure. One patient was reoperated to complete the excision of mesoappendix. All tumors were located at the tip of the appendix with a mean diameter of 0.6 cm (range: 0.3-1.0 cm). No adjuvant therapy was performed. All patients were alive and disease-free during a mean follow-up of 33 mo.

CONCLUSION: Appendiceal carcinoid tumor most often presents as appendicitis. In most cases, it is found incidentally during appendectomies and its diagnosis is rarely suspected before histological examination. Appendiceal carcinoid tumor can be managed by simple appendectomy and resection of the mesoappendix, if its size is ≤ 1 cm.

[Thyroid nodules]

Thyroid nodules are commonly encountered in clinical practice. They are present in 4 to 7% of the population by neck palpation and 30 to 50% by ultrasonography. Most are benign and could be neglected by the clinician and his patient. However, 5% of nodules are malignant, requiring surgical treatment; therefore, an exhaustive evaluation is needed. The diagnostic approach includes physical examination, laboratory analysis, ultrasonography, radioisotope imaging, and fine needle aspiration. This article, based on the literature and the authors'experience, provides recommandations for thyroid nodule management.

[How do you investigate an elevated calcitonin level?]

This article describes a case of lung cancer with associated hypercalcitoninemia in a man with a goitre. The case raises the problem of the differential diagnosis between medullary thyroid carcinoma and a neuroendocrine neoplasm with ectopic calcitonin secretion. The article first reviews the physiology of calcitonin, then outlines the diagnostic tests that are required to investigate hypercalcitoninemia and finally discusses the interpretation of test results.

Primary sarcoma of an abdominal aortic aneurysm

Primary tumors of the aorta are extremely rare and the diagnosis is made most often after surgery or autopsy. Because clinical symptoms of abdominal sarcoma are similar to those of occlusive or aneurysmal disease, aortic sarcomas are frequently mistaken for these lesions. The imaging findings are frequently nonspecific and therefore do not allow a definitive preoperative diagnosis. We report a case of an epithelioid angiosarcoma in the vessel wall of an abdominal aortic aneurysm.

Murine Bone Marrow Stromal Cells Sustain In Vivo the Survival of Hematopoietic Stem Cells and the Granulopoietic Differentiation of More Mature Progenitors

The study of the human hematopoietic system would be facilitated by availability of a relevant animal model. Because the medullar microenvironment is made of different types of cells, interactions between hematopoietic cells and stromal cells are difficult to analyze in detail. As an approach for establishing an in vivo model to dissect these interactions, we grafted murine bone marrow fibroblastic cells (MS-5 cell line) with hematopoietic cells into the kidney capsule of syngenic mice. To identify the origin of cells present in the graft, we used green fluorescent protein-stable transfected MS-5 cells for the transplantation. To analyze the evolution of stromal cells and identify hematopoietic cells able to develop in these conditions, we performed morphology, histochemistry, and immunohistology on tissue sections at different times after transplantation. When injected alone, MS-5 cells differentiate into adipocytes. When injected with a bone marrow suspension or with isolated CD45+ cells (leukocytes), the stromal cells keep their fibroblastic morphology and their alkaline phosphatase expression and sustain granulopoiesis. When injected with hematopoietic stem cells called c-kit+ Sca-1+ Lin- suspension, clusters of hematopoietic cells are also observed: They do not present any granulopoietic activity and do not belong to B or T population nor to erythroid lineage. They are quiescent, induce bone marrow recovery and survival of lethally irradiated recipients, are able to form macroscopic colonies in the spleen, and are able to form very few colonies in vitro, suggesting that they are hematopoietic stem cells. In conclusion, our results show that reticular fibroblastic stromal cells MS-5 sustain the survival of stem cells and are not able to induce their differentiation. However, they can control differentiation, proliferation, and/or survival of hematopoietic cells engaged in myeloid lineage.

[Alveolar echinococcosis]

Alveolar echinococcosis is a serious parasitic disease, leading to large hepatic lesions. It must be distinguished from cystic echinococcosis, or hydatic cyst, caused by Echinococcus granulosus. Early diagnosis may allow surgical removal of the lesions by segmental hepatectomy, the only curative treatment. Parasitostatic medical treatment with albendazole may promote stabilization of the disease. Until recently, Belgium was considered a country at very low risk for alveolar echinococcosis, as no human case was reported, despite up to 51% of fox infection in southern Belgium autopsy series. Recently four patients presented with alveolar echinococcosis at the University Hospital Center of Liege, leading to the fear of a possible alveolar echinococcosis endemy in southern Belgium. Two of these patients underwent curative hepatectomy, but the other two had already pulmonary metastases at diagnosis and received palliative albendazole therapy. This article presents these cases, and reviews the clinical features of this parasitic disease.

Endemic alveolar echinococcosis in Southern Belgium?

Until now, Belgium has been considered as a low-risk country for alveolar echinococcosis. However it was recently demonstrated by necropsy series that, in some parts of southern Belgium (Wallonia), up to 51% of the red foxes (Vulpes vulpes) may be infected by E. multilocaris. The authors, working in a university hospital in southern Belgium, described in 2002 the first autochthonous Belgian case of hepatic alveolar echinococcosis. More importantly, in 2004, they diagnosed three other patients with alveolar echinococcosis. One underwent surgical resection, but two others had bilateral pulmonary involvement at time of definite diagnosis. Palliative albendazole therapy was initiated. These patients had been diagnosed with hepatic mass from unknown origin for several months. The previous experience with the first case allowed the authors to consider and to confirm alveolar echinococcosis diagnosis, made by pathology and/or serological tests and imaging. These four patients with alveolar echinococcosis were living either in the Liege or the Luxembourg province. Considering the high prevalence of E. multilocaris infection of red foxes and the recent increase of the fox population due to rabies vaccination in southern Belgium, and also the presence of E. multilocaris infection of red foxes in northern Belgium, it is likely that not only Wallonia, but also maybe the whole Belgium, may face endemic alveolar echinococcosis in the next years.

Increased IL-6 and TGF-beta1 concentrations in bronchoalveolar lavage fluid associated with thoracic radiotherapy

PURPOSE

To assess, in lung cancer patients, the effects of thoracic radiotherapy (RT) on the concentrations of transforming growth factor-beta(1) (TGF-beta(1)) and interleukin-6 (IL-6) in the bronchoalveolar lavage (BAL) fluid.

METHODS AND MATERIALS

Eleven patients with lung cancer requiring RT as part of their treatment were studied. BAL was performed bilaterally before, during, and 1, 3, and 6 months after RT. Before each BAL session, the patient's status was assessed clinically using pulmonary function tests and an adapted late effects on normal tissue-subjective, objective, management, analytic (LENT-SOMA) scale, including subjective and objective alterations. The National Cancer Institute Common Toxicity Criteria were used to grade pneumonitis. The TGF-beta(1) and IL-6 levels in the BAL fluid were determined using the Easia kit.

RESULTS

The TGF-beta(1) and IL-6 concentrations in the BAL fluid recovered from the irradiated areas were significantly increased by thoracic RT. The increase in TGF-beta(1) levels tended to be greater in the group of patients who developed severe pneumonitis. In the BAL fluid from the nonirradiated areas, the TGF-beta(1) and IL-6 concentrations remained unchanged.

CONCLUSION

The observed increase in TGF-beta(1) and IL-6 concentrations in the BAL fluid recovered from the irradiated lung areas demonstrated that these cytokines may contribute to the process leading to a radiation response in human lung tissue.

Marrow stromal cell recovery after radiation-induced aplasia in mice

PURPOSE

The identification of fibroblast-like cells of the marrow stroma by means of alkaline phosphatase (ALP) cytochemistry reveals delicate ALP-positive structures interspersed among haematopoietic cells and arranged in a loosely meshed network. These cells are often referred to as 'reticular' cells and the network they form is known as the 'ALP network'. The purpose was to analyse the evolution of this ALP network in relation to haemopoietic regeneration after whole-body irradiation.

MATERIALS AND METHODS

The total surface occupied by ALP-positive processes revealed by means of ALP cytochemistry was expressed as a ratio of the total marrow area. ALP-positive cells were counted using nuclei as the defining unit. Cell proliferation was analysed by the detection of bromodeoxyuridine (BrdU) incorporation. Fat cells were identified by oil red O staining and alpha-glycerophosphate dehydrogenase (alpha-GPDH) activity.

RESULTS

The ALP network and ALP-positive cell number began to increase 24 h after 4-Gy irradiation to reach a maximum after 72 h, when the bone marrow was almost completely empty of haemopoietic cells. This increase was in advance of haemopoietic recovery and was not due to cell proliferation. A decrease in the ALP network occurred in parallel with an increase in haemopoiesis and was accompanied by a transient increase in fat cells on day 7.

CONCLUSIONS

These data indicate that the recovery of the ALP network, which is partially due to the recruitment of ALP- positive cells, occurs in advance of the haemopoietic recovery and that the equilibrium between fat cells and ALP-positive cells seems to be controlled by haemopoietic cells.

[Clinical case of the month. Constipation and abdominal mass syndrome in a 51-year-old patient]

A 51-year old patient consults for abdominal swelling and persistent constipation. Clinical exploration shows the presence of a left iliac fossa tumor corresponding to a papillary serous adenocarcinoma of the fallopian tube after macroscopic and microscopic examination. The diagnostic and therapeutic problems caused by this rare gynecologic tumor are discussed.

Fluorodeoxyglucose positron emission tomography and somatostatin receptor scintigraphy for diagnosing and staging carcinoid tumours: correlations with the pathological indexes p53 and Ki-67

We performed this study in order to evaluate the diagnostic accuracy of whole-body fluorodeoxyglucose positron emission tomography (FDG PET) imaging and somatostatin receptor scintigraphy (SRS) for localizing primary carcinoid tumours and evaluating the extent of the disease. A secondary aim was to correlate those findings with the histological characteristics of the lesions. FDG PET was performed in 17 patients and SRS in 16. All patients had pathologically proven carcinoids. All lesions were verified by histopathological analysis or by follow-up. Ki-67 and p53 expression were assessed as an indicator of the tumours' aggressiveness. FDG PET correctly identified 4/7 primary tumours and 8/11 metastatic spreads, as compared to six and 10 respectively, for SRS. Most tumours were typical carcinoids with low Ki-67 expression. No correlation was found between the histological features and the tracer's uptake. We conclude that SRS remains the modality of choice for evaluating patients with carcinoid tumours, regardless of their proliferative activity. FDG PET should be reserved to patients with negative results on SRS.

[Synovial metastases from colonic cancer presenting as arthritis of the knee. Characterization by 18FDG PET scan]

A case of carcinomatous monoarthritis involving the left knee due to colonic adenocarcinoma is described. Large recurrent synovial effusion, that will be later hematic, lytic lesion of the bones and chondrolysis were noted. Knee positron emitting tomography scan using FDG (FDG-PET) revealed a diffuse increased uptake in soft tissues assumed to be synovium, the hypertrophy of which was identified by ultrasonography. Whole body PET scan showed extensive lymph node, visceral and bone metastases, suggesting that the increase in the synovium could also be of metastatic origin. The final diagnosis of synovial carcinomatosis secondary to the known colonic adenocarcinoma was confirmed by histological analysis of biopsies obtained by arthroscopy. A review of the literature is realised. To our knowledge, this is the first synovial metastasis studied by FDG-PET.

Extensive inflammatory pseudotumor of the pituitary

A 40-yr-old female presented with an extensive lesion of the sellar area and the sphenoid sinus, spreading to the optic nerves and associated with pachymeningitis. Histological findings were consistent with an inflammatory pseudotumor, and steroid treatment allowed the disappearance of all the lesions. Inflammatory pseudotumors of the pituitary are very rare. This case appears unique with regard to the extension of the lesions and the dramatic response to medical treatment. The differential diagnosis of inflammatory lesions of the pituitary is difficult. It relies mainly on histological analysis and includes sarcoidosis, Wegener's granulomatosis, histiocytosis (Langerhans, Rosai-Dorfman, and Erdheim-Chester diseases) and lymphocytic hypophysitis.

Nicardipine protocol for CABG using the radial artery clinical and angiographic data

The routine use of arterial grafts in coronary surgery is facilitated by peroperative adjunction of antispasmodic drug to reduce the event of spasm. Diltiazem has been favoured in most clinical studies devoted to the radial artery graft. The aim of this study was to assess the efficacy of a spasm preventing protocol associating hydrostatic dilation of the graft with a diluted solution of papaverine and nicardipine infusion, starting preoperatively and continued postoperatively in i.v. and per os forms. Between September 1996 and March 1997, a consecutive series of 50 patients underwent myocardial revascularization using the radial artery. The radial artery was prepared by hydrostatic dilation with papaverine (1%) and nicardipine was administrated at 0.25 microgram/kg/min and titrated according to the arterial systemic pressure. Operative mortality was 4% (sepsis). There was no evidence of perioperative MI nor hypoperfusion syndrome. Mean CKMB level at 18 hours was 36 micrograms/l. No ischaemic anomalies of the ECG were detected. Angiography performed in the last 20 patients showed a 98% (51/52) permeability rate for all graft; 19/20 radial grafts (95%) were patent. One radial graft presented a 50% stenosis at the proximal anastomosis, and another a moderate spasm (40%) in the middle part of the conduit. This study confirms that the radial artery conduit can be used with satisfactory results for routine coronary artery bypass. The use of nicardipine allows the control the vasoreactivity of the radial graft without totally obviating at least angiographic spasm. This drug is easy to titrate, and well tolerated in association to beta-blockers in the routine perioperative management of the coronary patients.

Translocation (16;17)(q22;p13) is a recurrent anomaly of aneurysmal bone cysts

Recently, Panoutsakopoulos et al. (1999) reported 2 cases of aneurysmal bone cysts with a recurrent (16;17)(q22;p13) translocation. We present here two additional cases harboring the same translocation as well as additional chromosomal changes.

[Extensions of mitral valve repair techniques: surgery for endocarditis and valvular tumors]

Mitral valve repair has demonstrated its superiority over valve replacement. Mitral valve repair constitutes the optimal therapeutic option in case of degenerative dystrophic, rheumatic, congenital or ischemic mitral valve disease. These surgical techniques can also be successfully and advantageously applied in case of bacterial endocarditis or tumoral valvular disease. We report a case of staphylococcal endocarditis and another case of posterior leaflet fibroelastoma to show the place of conservative mitral surgery in these unusual indications.

[Anatomic clinical case. Septic state in a patient with chronic obstructive lung disease]

Invasive aspergillosis is a mycelial infection, associated in 15 to 30% of cases with a malignant hemopathy or with other types of cancers. It also constitutes a complication induced by high dosage corticotherapy or long term antibiotherapy. On the occasion of an autopsy of invasive aspergillosis, we review the anatomo-clinical entities associated with aspergillus, the etiopathogenic factors and the diagnostic difficulties.