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D Parent

Publications and source records attributed to D Parent.

At least 19 recordsLinked to original sources
PubMed1998

Iron as a potential co-factor in the pathogenesis of Kaposi's sarcoma?

The role of iron in the pathogenesis of several tumours is being increasingly investigated. In particular, its involvement in the pathogenesis of Kaposi's sarcoma (KS) is suggested by the distribution of the endemic form of KS corresponding to continental rifts and associated iron-oxide-rich volcanic clays. We investigated in vitro to what extent iron supplementation or withdrawal could affect the growth of KS-derived cells, by analysing the effects of adding iron salts (iron chloride and ferric nitrilotriacetate) and/or reducing iron by iron chelators (desferrioxamine) on KS-derived cell cultures. The addition of iron salts strongly stimulated the growth of KS cells, as reflected by increase in thymidine incorporation and cell number. Conversely, desferrioxamine and deferiprone inhibited cell growth. The inhibitory effect of iron chelation was more pronounced on rapidly dividing basic fibroblast-growth-factor-stimulated cells. These results may point to a novel therapeutic approach to KS.

Carcinogens↗
PubMed1998

Constitutive release of metalloproteinase-9 (92-kd type IV collagenase) by Kaposi's sarcoma cells.

Kaposi's sarcoma (KS) is an angioproliferative disease characterized by proliferating spindle-shaped cells, angiogenesis, and inflammatory cell infiltration. Several lines of evidence suggest that KS is a multifocal cytokine-mediated disease of vascular origin. Because metalloproteinases (MMPs) are important enzymes involved in angiogenesis, we studied their activity in five different KS-derived cell lines and compared these data with those obtained with human umbilical vein endothelial cells (HUVEC). We focused on the activity of the 72- and 92-kd type IV collagenases because these enzymes are thought to play an important role in the process of tumoral invasion. Nonstimulated HUVEC released a weak 72-kd collagenase activity and no 92-kd collagenase activity, as determined by zymographic analysis. Stimulation of HUVEC with phorbol myristate acetate (PMA) or TNF-alpha increased the 72-kd collagenase activity and also induced a 92-kd collagenase activity. By contrast, KS-derived cells constitutively released significant 72- and 92-kd collagenase activities. The basal release of these enzymes by KS cells was further enhanced by TNF-alpha or PMA. Conversely after in vivo exposure to chemotherapy, KS-derived cells showed a downregulation of the production of MMPS that could be reversed by the addition of TNF or PMA. These results suggest that KS cells have constitutive features of activated cells that have an invasive and metastasizing potential.

Cells, Cultured↗
PubMed1998

PCR assay fails to detect molluscum contagiosum virus-related sequences in AIDS-related Kaposi's sarcoma.

Previous PCR-based studies have demonstrated the presence of various viral DNA or RNA sequences in Kaposi's sarcoma (KS) tissues. To date, only human herpesvirus 8 (HHV-8) DNA sequences are found consistently in KS. The putative role of this agent in KS pathogenesis remains, however, to be determined; HHV-8 could infect populations endemically and could be reactivated in patients with KS. A close association between AIDS-related KS and molluscum contagiosum occurrence was found and this study was conducted primarily to search for the presence of molluscum contagiosum virus DNA sequences in KS. Frozen KS samples were examined for the presence of both HHV-8 and molluscum contagiosum virus DNA sequences by PCR. Despite a high rate of co-infection, no molluscum contagiosum virus (MCV) DNA sequence could be found in the KS samples whereas HHV-8 was uniformly detected. These results suggest that the high prevalence of MCV in AIDS patients with KS relies on a mode of transmission common for HHV-8 and molluscum contagiosum virus rather than on a multiviral etiology of KS. They may also indicate a particular susceptibility of the host to viral reactivation. If this is so, the failure to detect MCV DNA sequences in KS tissues by PCR indicates that locally produced or released cyotokines are not involved in the latter process.

AIDS-Related Opportunistic Infections↗
PubMed1998

Overexpression of Bcl-2 in Kaposi's sarcoma-derived cells.

The pathogenesis of Kaposi's sarcoma (KS), a tumor of probable vascular origin, remains an enigma. It is still unclear whether KS is a true malignancy or whether it represents a reactive polyclonal process. Using both an immunohistochemical and an immunoblot approach, we found that cells derived from KS lesions express significant levels of Bcl-2, a protein known to prolong cellular viability and to antagonize apoptosis. Bcl-2 expression was found in AIDS-related KS-derived cells, as well as in cells derived from iatrogenic and sporadic KS, indicating that Bcl-2 upregulation may be important in the pathogenesis of KS regardless of its epidemiologic form. By contrast, fibroblasts and dermal microvascular endothelial, cells which are the probable vascular progenitors of KS cells, expressed low levels of Bcl-2. The expression of Bcl-2 in KS-derived cells was associated with a long-term survival in serum-deprived conditions, a situation that has been shown to induce apoptosis in various cell types. Incubation of fibroblasts or of dermal microvascular endothelial cells with KS cell-free supernatants did not enhance Bcl-2 expression, suggesting that Bcl-2 expression is not mediated by an agent released by KS cells. Analogously, KS supernatants failed to promote the viability of fibroblasts and of dermal microvascular endothelial cells cultured in serum-free conditions. Our findings suggest that the spindle cells derived from KS have a survival advantage and may adequately represent the tumor cells of KS.

Cell Survival↗
PubMed1998

Role of viral agents in the pathogenesis of Kaposi's sarcoma.

Several viruses have been detected, at various frequencies, in Kaposi's sarcoma (KS) tissues. The detection of human herpesvirus 8 (HHV-8) in all the epidemiological and histological forms of KS makes it the most attractive candidate causative agent to date. In this report, we discuss the possible explanations for the detection of genomic sequences of various viral agents in KS and the putative role of those viruses in the pathogenesis of the disease.

Herpesviridae Infections↗
PubMed1998

Granulomatous vulvitis, granulomatous cheilitis: a single diagnosis?

We report two cases of labial swelling (oral and vulvar) with a granulomatous histology in patients with a history of Crohn's disease. The differential diagnosis of granulomatous vulvitis and cheilitis, as well as the symptomatology and treatment of vulvar and oral Crohn's disease are further discussed. To our knowledge, reported cases of vulvar and oral Crohn's disease are quite scarce in the literature, but the disease might be underdiagnosed. We hope to contribute to an earlier recognition and a better management of the vulvar and oral mucocutaneous lesions of Crohn's disease.

Adult↗
PubMed1998

Tuberculous inguinal and crural lymph nodes.

Non-respiratory forms of tuberculosis are frequently described in immigrants from endemic countries and in immunocompromised patients. Among the extrapulmonary forms of tuberculous disease, peripheral lymph node involvements, generally cervical, are the most common. Interestingly, only a few cases of tuberculous inguinal adenitis have been reported in the literature during the last 15 years. We report 2 cases of isolated inguinal inflammatory lymph-adenitis observed in immigrant immunocompetent women. The diagnosis of tuberculosis was confirmed by culture obtained by needle aspiration of a lymph node. The lesions completely healed after standard antituberculous therapy.

Adult↗
PubMed1998

Treatment of classical Kaposi's sarcoma with intralesional injections of cidofovir: report of a case.

The effect of intralesional injections of cidofovir, a nucleotide analog with potent in vitro activity against human herpesvirus 8 (HHV-8), was studied in vivo in an HIV-negative patient with classical Kaposi's sarcoma (KS). After five weekly injections of the drug, no clinical, histological, immunohistological, or virological changes could be detected in comparison with saline-injected lesions. These findings suggest that, once the KS tumor has developed, active viral replication is no longer involved in the pathogenesis of the disease. Alternative hypotheses are that HHV-8 replication in blood-borne cells may foster growth of spindle cells in the skin, or that blocking HHV-8 may not affect existing lesions but may prevent new lesions from developing.

Aged↗
PubMed1998

[Viral sexually transmitted diseases and their treatments].

In occidental countries, the sexually transmitted diseases (STDs) originate mostly from virus: human papillomavirus (HPV) and Herpes simplex virus (HSV). During the latest 15 to 20 years, their prevalence has been regularly growing. Those viruses have in common a capacity for latency. The persistence of the virus in keratinocytes (PVH) or in ganglionic cells (HSV) and the lack of an efficient preventive or final curative treatment have several consequences: 1) a possible capacity of transmitting itself during sexual intercourse in the absence of clinical lesions, 2) a potency to recur all along the life especially when the organism suffer from immunodepression (patients with graft, chimiotherapy or AIDS). The oncogenic capacity of some HPV subtypes in anogenital cancers is now recognized. Those neoplasias are observed most often in immunodepressed patients but are nevertheless classically found in the uterine cervix of immunocompetent women. Genital herpes is often clinically diagnosed but its confirmation is obtained through isolating the HSV from the liquid of the vesicles or from a swab of the lesion. Biopsy is not usually useful. For HPVs, it is different since culture of papillomavirus is not possible. Diagnosis can then be get through biopsy: specific features (koïlocytes) or HPV identification. Treatments are also totally different. Since the appearance of aciclovir, followed by valaciclovir and famciclovir, antiviral drugs are available against herpes. There is no antiviral drug against HPV. The HPV infections are treated through destroying the clinical lesions: laser, cryotherapy, podophylline...

Antiviral Agents↗
PubMed1997

Cutaneous necrotizing vasculitis after low dose methotrexate therapy for rheumatoid arthritis: a possible manifestation of methotrexate hypersensitivity.

Large haemorrhagic and necrotic cutaneous lesions developed after two low dose (5 mg) methotrexate injections in a patient suffering from long standing rheumatoid arthritis. Differential clinical diagnosis included factitia dermatitis, infectious processes, pyoderma gangrenosum, rheumatoid neutrophilic dermatitis, necrotizing arteritis and vasculitis. Histological and direct immunofluorescent examinations of skin biopsies supported the diagnosis of leucocytoclastic vasculitis. We discuss the respective roles of methotrexate and rheumatoid arthritis in the outbreak of leucocytoclastic vasculitis. Hypersensitivity is strongly suspected.

Antirheumatic Agents↗
PubMed1996

Decreased skin reactivity to codeine in patients with the acquired immunodeficiency syndrome.

To evaluate the skin reactivity and the mast cell releasibility in the acquired immunodeficiency syndrome (AIDS), 24 patients with AIDS were skin tested with histamine (1 mg/ml) and codeine phosphate (0.9, 0.09, and 0.009 mg/ml), a mast cell degranulating agent. They were compared to 12 HIV-negative healthy volunteers and 16 urticaria-prone subjects. Reactivity to codeine phosphate was lower in patients with AIDS than in HIV-negative subjects. This difference in skin reactivity was the more significant when the AIDS group was compared to the urticaria-prone group. There was no correlation between the reactivity to codeine and the IgE levels. Possible explanations to the decreased skin reacting to codeine in patients with AIDS include a decrease of local mast cell density or releasibility. This suggests that a mechanism related to urticaria and involving mast cells is quite unlikely to be at the origin of the hypersensitivity reactions observed in AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Therapy of bacterial vaginosis using exogenously-applied Lactobacilli acidophili and a low dose of estriol: a placebo-controlled multicentric clinical trial.

The efficacy of vaginal tablets (Gynoflor) containing 50 mg of a lyophilisate of viable, H2O2-producing Lactobacillus acidophilus (at least 10(7) colony forming units/tablet) and 0.03 mg estriol (CAS 50-27-1) for the treatment of bacterial vaginosis (BV) was tested in a multicentric, randomised, placebo-controlled clinical trial with parallel-group design. 32 non-menopausal women with positive diagnoses for BV, including intermediate cases, participated in the trial. Patients were diagnosed using the classical clinical parameters of BV according to Amsel and using microscopic analysis of the Gram-stained vaginal smear. A positive clinical diagnosis of BV required at least 2 of the following 4 clinical criteria to be positive; greyish-white, homogeneous leukorrhea; vaginal pH > 4.5; KOH test for volatile amines; presence of clue cells. Microscopic diagnosis of BV, on the other hand, was obtained if examination of the Gram-stained vaginal smear showed less than 6 lactobacilli per field of view (1000 x magnification). This corresponds to another definition of BV as "lactobacilli deficiency syndrome". The efficacy of the 6-day therapy with 1-2 vaginal tablets daily was evaluated using both clinical and microscopic analysis. Using Amsel's classical clinical parameters of BV, the cure rate (defined as < or = 1 of the 4 clinical criteria positive) two weeks after the start of therapy was 77% in the verum group and 25% in the placebo group. Four weeks after the start of therapy, the cure rate was 88% in the verum group and 22% in the placebo group. At both control examinations, the cure rate for the test group was significantly higher than that for the placebo group (p < 0.05, Fisher's exact test, 2-sided, significance level 0.05). In addition, the trial showed that after 6 days of treatment with the test preparation, the lactobacilli were capable of recolonising the vagina. A significant increase in the number of lactobacilli was observed in the Gram-stained vaginal smear for the patient group treated with the test preparation compared to the placebo patient group (p < 0.05, Fisher's exact test, 2-sided, significance level 0.05), two and four weeks after the start of the 6-day treatment.

Adult↗