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Biomedical subjects

T Simonart

Publications and source records attributed to T Simonart.

At least 19 recordsLinked to original sources
PubMed2001

Impact of surgical resection of rectovaginal pouch of douglas endometriotic nodules on pelvic pain and some elements of patients' sex life.

STUDY OBJECTIVE: To assess the impact of laparoscopic resection of endometriotic nodules in the rectovaginal pouch of Douglas on women's pain symptoms, analgesic intake, work absenteeism, work difficulties, and some elements of sex life. DESIGN: Observational study (Canadian Task Force classification II-2). SETTING: Gynecology department at a university hospital. PATIENTS: Twenty-six women with rectovaginal pouch of Douglas endometriotic nodules and no evidence of other potential cause of pain at physical examination, laparoscopy, and transvaginal ultrasonography. INTERVENTION: Laparoscopic resection of endometriotic nodules with the CO2 laser until no residual induration was felt in surrounding tissues. MEASUREMENTS AND MAIN RESULTS: Significant statistical differences were found between preoperative and postoperative pain scores, percentages of women absent from work, percentages taking analgesics or nonsteroidal antiinflammatory drugs, and percentages having work difficulties due to pain. A significant difference also was found in frequencies of sexual desire and coitus. CONCLUSION: Endometriotic nodules in the rectovaginal pouch of Douglas may be responsible for major pelvic pain and also for sexual dysfunction (lack of sexual desire, dyspareunia). Laparoscopic resection of the nodules significantly improves these conditions. (J Am Assoc Gynecol Laparosc 8(1):55-60, 2001)

Adult↗
PubMed2001

Kaposi's sarcoma, oncogenic viruses, and iron.

INTRODUCTION: Iron is required for many cellular processes, but it is also toxic in excess quantities. Therefore, iron homeostasis and utilization must be strictly maintained, and defects in iron absorption or transport result in iron depletion or accumulation. Most research has been directed to enteral and placental transfer of iron, but little is known about iron entry through the skin. We present evidence that exposure to wet clay soils in Africa is an important risk factor for Kaposi's sarcoma (KS) and speculate that iron may be responsible for soil toxicity contributing to the pathogenesis of KS. STUDY DESIGN: Evidence gathered from case control studies and related investigations in Uganda between 1995 and 1998 are summarized. RESULTS: A large case control study of KS in HIV-infected adults disclosed affluence and mobility that suggest enhanced sexual exposure to human herpesvirus-8, the putative aetiologic agent of KS. Another study in endemic KS (HIV-negative) also showed affluence and mobility as risk factors. In addition, barefoot exposure to wet soil was an important risk factor for men with endemic KS. Other studies point to diminish delayed hypersensitivity in the lower limbs of KS patients. Geographic similarities of KS to podoconiosis (non-filarial elephantiasis) in Africa implicate soil absorbtion through the skin in the pathogenesis of KS and podoconiosis. CONCLUSION: The hypothesis of soil exposure as a risk for endemic KS has been strengthened by recent investigation. Particulate soil exposure may cause localized microtrauma and inflammation, predisposing to KS on the extremities in HHV-8 infected men. A role for iron toxicity is yet to be determined.

Case-Control Studies↗
PubMed2001

Early- and late-stage Kaposi's sarcoma-derived cells but not activated endothelial cells can invade de-epidermized dermis.

Whether Kaposi's sarcoma is a true neoplasm or a reactive endothelial cell outgrowth triggered by inflammatory cytokines remains unclear. In this study, we investigated the differential invasive properties of activated endothelial cells and Kaposi's sarcoma cells in a model of de-epidermized dermis, supplying the cells with matrix barriers similar to those found in vivo. Cells derived from early "patch-stage" and from late "nodular-stage" Kaposi's sarcoma lesions exhibited similar invasive properties, which indicates that cells with an invasive potential are present in the early stages of tumor development. Slow accumulation of the cells into the extracellular matrix, together with a low proliferation index and with expression of anti-apoptotic proteins, suggest that the progression of Kaposi's sarcoma may be related to escape from cell death rather than to increased proliferation. The Kaposi's sarcoma-Y1 cell line, which is tumorigenic in nude mice, also exhibited invasive properties. By contrast to the Kaposi's sarcoma-derived spindle cells, however, which were scattered between the collagen bundles, the Kaposi's sarcoma-Y1 cell population had a higher proliferation index and displayed a multilayer arrangement. Inflammatory cytokines and Kaposi's sarcoma cell supernatant could activate and stimulate the growth of human dermal microvascular endothelial cell, but could not induce their invasion in this model, showing that activated endothelial cells do not fit all the requirements to traverse the various barriers found in the dermal extracellular matrix. These results confer to Kaposi's sarcoma cells a tumor phenotype and suggest that the in vivo dominant endothelial cell population represents a reactive hyperplasia rather than the true tumor process.

Cell Division↗
PubMed2001

Iron induces Bcl-2 expression in human dermal microvascular endothelial cells.

Iron is suspected to be involved in the induction and/or progression of various human tumors. The present study was designed to investigate the effects of iron on endothelial cells, keeping in mind that the homeostasis of microvessels plays a critical role in neo-angiogenesis. Applying a model of human dermal microvascular endothelial cell terminal differentiation and death induced by serum deprivation, we found that iron salts (iron chloride and ferric nitrilotriacetate) provided a survival advantage to endothelial cells. Using immunohistochemistry and Western Blot analysis, we found that the extended cellular life span induced by iron was paralleled by an increase of Bcl-2 protein expression. Taken together, these observations suggest that iron may give a survival advantage to endothelial cells and represent a novel mechanism through which iron may contribute to tumorigenesis.

Cell Line↗
PubMed2001

Value of standard laboratory tests for the early recognition of group A beta-hemolytic streptococcal necrotizing fasciitis.

The laboratory data for 17 patients with group A beta-hemolytic streptococcal necrotizing fasciitis (GAS NF) were compared with data for 145 patients hospitalized for cellulitis during the same period. Admission values of C-reactive protein and creatine kinase were higher for patients in the group with GAS NF than for patients in the group with cellulitis (P<.001), suggesting that standard laboratory tests may be useful for the early differential diagnosis of GAS NF and cellulitis.

Adolescent↗
PubMed2000

Kaposi's sarcoma.

Explore the source record for details and available documents.

Chorionic Gonadotropin↗
PubMed2000

Multinucleate cell angiohistiocytoma: report of two cases with no evidence of human herpesvirus-8 infection.

Multinucleate cell angiohistiocytoma (MCA) is a vascular tumor of unknown pathogenesis. Possible misinterpretation of this disorder with Kaposi's sarcoma (KS), a human herpesvirus-8 (HHV-8)-associated tumor, prompted us to look for this virus in two women with MCA. None of the multiple skin specimens obtained from both our patients produced amplified HHV-8 DNA. Using a cell culture methodology similar to that used for KS, we established cell cultures from MCA lesions. While KS spindle cells are known to exhibit in vitro invasive properties and can be grown up to more than 20 passages, the MCA-derived cells were short-lived and were not able to traverse basement membranes. Taken together, our data support the hypothesis that MCA is not a neoplasm but a benign vascular proliferation which is clearly distinguishable from KS.

Aged↗
PubMed2000

Langerhans' cell histiocytosis arising at the site of basal cell carcinoma excision.

Langerhans' cell histiocytosis (LCH) may be associated with a wide range of neoplastic disorders. However, the combination of a LCH and a basal cell carcinoma (BCC) of the skin still represents a highly unusual condition. In this publication, we report the case of a 48-year-old woman who developed a localized LCH involving the area of a previously excised BCC. Although the exact pathogenesis of this peculiar association remains yet to be elucidated, the hypothesis of an exaggerated Langerhans' cell reaction in response to the underlying BCC appears to be attractive.

Basal Cell Carcinoma↗
PubMed2000

Iron chelators inhibit the growth and induce the apoptosis of Kaposi's sarcoma cells and of their putative endothelial precursors.

Iron is suspected to be involved in the induction and/or progression of various human tumors. More particularly, iron may be involved in the pathogenesis of Kaposi's sarcoma, a tumor of probable vascular origin. This study was designed to investigate the effect of iron deprivation on Kaposi's sarcoma. The effects of iron chelators and iron deprivation associated with serum withdrawal were investigated on Kaposi's sarcoma-derived spindle cells, on a transformed Kaposi's sarcoma cell line (Kaposi's sarcoma Y-1) and on endothelial cells, which are the probable progenitors of Kaposi's sarcoma cells. Desferrioxamine and deferiprone, two chemically unrelated iron chelators, induced a time- and concentration-dependent inhibition of endothelial and Kaposi's sarcoma cell growth. The inhibition of cell growth was associated with a decrease in Ki-67 and in both stable and total proliferating cell nuclear antigen expression. Inhibition of the progression through the G1-phase of the cell cycle was further evidenced by decreased expression of cyclin D1 and of p34 cyclin-dependent kinase 4. Terminal deoxynucleotidyl transferase-mediated desoxyuridinetriphosphate nick end labeling assay, flow cytometry with annexin-V-fluorescein and morphologic analysis indicated that iron chelation also induced a time- and concentration-dependent apoptosis. This apoptotic effect was prevented by the addition of exogenous iron. Induction of iron deprivation in the culture medium by serum withdrawal led to similar cell cycle effects, which, however, could only be partly reverted by the addition of exogenous iron. In conclusion, these results show that iron deprivation inhibits the growth and induces the apoptosis of Kaposi's sarcoma cells and of their putative endothelial precursors. This suggests that iron chelators may represent a potential therapeutic approach for the treatment of Kaposi's sarcoma.

Apoptosis↗
PubMed2000

Relationship between endometriotic foci and nerves in rectovaginal endometriotic nodules.

The histological relationships between fibrotic tissue, endometriotic foci and nerves in the rectovaginal septum endometriotic or adenomyotic nodule were studied. This is considered to be one of the most severe forms of deep endometriosis. Masson's trichrome staining for fibrosis detection and immunohistochemistry with the S100 monoclonal antibody for nerve detection were performed in 28 rectovaginal endometriotic nodules from patients presenting with severe dysmenorrhoea and deep dyspareunia (23 patients with no other endometriotic location or potential cause of pain at laparoscopy and ultrasonography; five patients with multiple pelvic endometriotic localizations and other potential causes of pain at laparoscopy). Patients were allocated to two groups on the basis of their preoperative pain scores for pelvic pain, dysmenorrhoea and deep dyspareunia (group 1, score >7; group 2, score < or =7). For each symptom, the mean number of nerves and endometriotic lesions per high-power field and the mean largest diameter of the lesions were not statistically different in groups 1 and 2. The mean percentages of nerves located within the fibrosis of the nodule and within endometriotic lesions were significantly higher in group 1 than in group 2. Among nerves located within endometriotic lesions, there was a significantly higher proportion showing intraneurial and perineurial invasion by endometriosis in group 1 than in group 2. In rectovaginal endometriotic nodules, there was a close histological relationship between nerves and endometriotic foci, and between nerves and the fibrotic component of the nodule. We postulate that such topographical relationships could at least partially explain the strong association between this lesion and pain.

Adult↗
PubMed2000

Phenotypic characteristics of Kaposi's sarcoma tumour cells derived from patch-, plaque- and nodular-stage lesions: analysis of cell cultures isolated from AIDS and non-AIDS patients and review of the literature.

BACKGROUND: Kaposi's sarcoma (KS) is commonly thought to be derived from endothelial cells because of the predominant expression of endothelial markers in KS lesions. However, the heterogeneity of the spindle-cell compartment makes the precise lineage relationship of KS tumour cells unclear. Cultured KS-derived spindle cells constitutively overexpress antiapoptotic proteins and exhibit invasive properties, which suggests that they may adequately represent the tumour cells of KS. OBJECTIVES: We aimed to investigate the expression of a wide variety of immunohistochemical markers by spindle cells derived from patch-, plaque- and nodular-stage lesions from patients with iatrogenic, sporadic and acquired immune deficiency syndrome-related KS, and to review the data reported by other laboratories. METHODS: Cells from six KS cell cultures derived from four subjects were examined by immunostaining. RESULTS: Comparison of these data indicates that KS-derived spindle cells generally express myofibroblast antigens but lack endothelial and/or leucocyte markers. CONCLUSIONS: As the myofibroblast phenotype is not the predominant feature of KS tissues, our findings further substantiate the view that the in vivo dominant endothelial population represents a reactive hyperplasia rather than the true KS tumour process.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Role of iron in dermatology.

Iron is involved in several biological reactions and is essential to almost all forms of life. In contrast, iron is potentially toxic. It may participate in many dermatological disorders, including pigmentation changes, inflammation, porphyrias, infections and cancers. The involvement of iron in these disorders entails a variety of mechanisms, including among others simple deposition processes, activation or inactivation of enzymatic systems, impairment of phagocyte functions and interference with apoptosis. A better understanding of the role of iron might provide novel therapeutic strategies based on iron-chelating and/or anti-oxidant agents.

Humans↗