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Biomedical subjects

T Appelboom

Publications and source records attributed to T Appelboom.

At least 19 recordsLinked to original sources

Big prolactin 60 kDa is overexpressed in salivary glandular epithelial cells from patients with Sjögren's syndrome.

Characterization of endogenous synthesis of prolactin (PRL) proteins and their cellular localization in labial salivary glands of patients with Sjogren's syndrome (SS) were achieved. PRL, PRL-receptors (PRL-R), and S100A6 protein were detected by immunohistochemistry. In situ prolactin synthesis was investigated in controls and SS patients by ex vivo incubation of minor salivary glands biopsies and immunoprecipitation assay. Increased PRL-immunoreactivity was found in cytoplasmic acinar epithelial cells in SS patients compared with normal subjects. PRL-R was distributed only in ductal epithelial cells in which S100A6 protein (a PRL-R-associated protein) was also present. PRL, PRL-R, or S100A6-immunoreactivity was not detected in infiltrating mononuclear cells. Immunoprecipitation demonstrated that PRL synthesis occurred in minor salivary glands with increased synthesis of two distinct PRL-like proteins (one major band at 60 kDa and a minor at 16 kDa) in SS glands compared with normal glands. Expression of PRL gene was demonstrated in SS salivary glands using RT-PCR. A positive correlation was found between the presence of PRL-like proteins in acinar epithelial cells of SS patients and clinical extraglandular manifestations. The presence of anti-Ro and anti-La antibodies also positively correlated with a higher percentage of PRL in acinar epithelial cells. In conclusion, PRL-like proteins are synthetized and overexpressed in glandular epithelial cells of labial salivary glands from SS patients and correlate with the aggressiveness of the disease.

Adult↗

Antiinflammatory properties of mycophenolate mofetil in murine endotoxemia: inhibition of TNF-alpha and upregulation of IL-10 release.

Mycophenolate mofetil (MMF) is a new immunosuppressive agent currently used in organ transplantation and under evaluation in immune-mediated inflammatory disorders such as rheumatoid arthritis. Although MMF was shown to inhibit purine nucleotide synthesis in lymphocytes, it is still unclear whether it might also exert direct antiinflammatory actions in vivo. To address this question, we evaluated the effects of MMF administration on the responses of mice to a single challenge with bacterial lipopolysaccharide (LPS). We observed that MMF treatment inhibits the release of tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) upon LPS injection whereas it promotes IL-10 production. In parallel, MMF was found to protect mice from LPS-induced lethality. Inhibition of TNF-alpha release was also observed in IL-10-deficient mice indicating that it does not exclusively depend on the upregulation of IL-10 endogenous synthesis. In view of the differential effects of MMF on the LPS-induced production of TNF-alpha and NO on one hand and that of IL-10 on the other hand, we conclude that beside its immunosuppressive action at the lymphocyte level, MMF is also endowed with antiinflammatory properties.

Animals↗

Zidovudine in primary Sjögren's syndrome.

OBJECTIVE: To evaluate the efficacy of the administration of zidovudine (AZT), an antiretroviral drug, in patients with primary Sjögren's syndrome (SS). METHODS: Seven female patients (age 57 +/- 8.6 yr) with primary SS were enrolled in an open, uncontrolled trial of AZT (250 mg b.i.d.) for the treatment of primary SS. The efficacy variables were oral and ocular dryness symptoms, fatigue, tender points, physician's and patient's global assessments (GA), ocular function tests (fluorescein tear break-up time, Schirmer's test, Rose Bengal staining) and laboratory parameters [erythrocyte sedimentation rate (ESR), serum IgG, IgA and IgM]. RESULTS: A significant improvement was observed in all subjective manifestations, as well as the objective parameters of ocular dryness. The treatment was well tolerated, except for mild and transitory gastrointestinal disturbances in 6/7 patients. Laboratory parameters did not change significantly. The clinical benefit persisted in 5/7 patients 1 month after the end of therapy. CONCLUSION: AZT seems to be effective and well tolerated in patients with primary SS.

Anti-HIV Agents↗

D-mannose and N-acetylglucosamine moieties and their respective binding sites in salivary glands of Sjögren's syndrome.

OBJECTIVE: Sjögren's syndrome (SS) is an autoimmune exocrinopathy. The mannose binding lectin (MBL), a pluripotent molecule of the innate immune system, is involved in the pathogenesis of autoimmune diseases. We investigated whether specific ligands for MBL and MBL related structures could be reliable markers in cases of SS. METHODS: The labial salivary glands of 19 patients fulfilling the diagnostic criteria for primary (n=11) and secondary SS (n=8) were studied. Seven healthy women served as controls. Computer assisted microscopy was employed to determine quantitatively the percentage of positive structures (acini, ducts, and interlobular connective tissue), the staining intensity, and the level of staining heterogeneity for 4 glycohistochemical probes including wheat germ agglutinin and concanavalin (Con A) as lectins, and mannose and N-acetylglucosamine as parts of neoglycoproteins. The data were evaluated by discriminant analysis. RESULTS: The data strongly suggest that MBL related structures, if not MBL itself, could play distinct roles in the pathogenesis of primary versus secondary SS. Further, quantitative determination of the level of expression of D-mannose and N-acetylglucosamine and their respective binding sites in labial salivary gland acini offers a powerful diagnostic tool for distinguishing primary from secondary SS. CONCLUSION: In SS labial salivary glands, determination of the level of acceptor sites for wheat germ agglutinin, Con A, D-mannose, and N-acetylglucosamine provides information on the roles played by glycoforms in SS. The methodology and data described in this paper should provide pathologists with objective diagnostic markers for SS. Our results should enhance the biological understanding of this pathology.

Acetylglucosamine↗

[How to evaluate osteoporosis: bone densitometry and biochemical tests].

The use of bone densitometry, by dual energy x-ray absorptiometry, allows the identification, at an early stage, of subjects who will, 15-20 years later, present a fracture event. Furthermore, this technique is the most appropriate to confirm the efficacy of preventive or curative therapeutic approaches of osteoporosis. A balanced utilisation of biochemical tests is mandatory to exclude a secondary cause of osteoporosis, to help in the choice of the most appropriate therapeutic strategy and to evaluate the early response of patients to the administered drugs.

Absorptiometry, Photon↗

[Postmenopausal osteoporosis in women].

Postmenopausal osteoporosis is now considered a major public health problem in aging women, due to the burden related to the consequent fractures. Over recent years, several pharmacological approaches were developed for the prevention and treatment of osteoporosis. Besides regular physical exercise and calcium rich diet, calcium supplementation can be suggested to both genders, after seventy years as well as systematic vitamin D supplementation in order to cope with the frequent lack observed in our country. Hormone replacement therapy is the first choice in prevention of postmenopausal osteoporosis. Based on a careful evaluation of the needs of a postmenopausal woman as well as on the risk/benefit ratio derived from her individual risk factors, selective estrogen receptor modulators (raloxifene) or second generation bisphosphonates (alendronate) can be considered as alternative to estrogens. Due to its prohibitive cost, nasal calcitonin should be only considered for very specific cases. In osteoporosis confirmed by bone densitometry or by occurrence of fractures, bisphosphonate (alendronate) reduces subsequent fracture rate. Fluoride salts can, in some cases, improve spinal symptomatic osteoporosis. The use of etidronate, a molecule from the past, should be avoided as much as possible and, at any rate, strictly restricted to its legal indication including women with several vertebral crush fractures and severely decreased bone mineral density.

Aged↗

Fluoride salts are no better at preventing new vertebral fractures than calcium-vitamin D in postmenopausal osteoporosis: the FAVOStudy.

Although fluoride salts have been shown to be capable of linearly increasing spinal bone mineral density (BMD) in postmenopausal osteoporosis, the effects of this gain in density on the vertebral fracture rate remain controversial. We conducted a 2-year multicenter, prospective, randomized, double-masked clinical trial in 354 osteoporotic women with vertebral fractures (mean age 65.7 years). They received either fluoride (208 patients), given as sodium fluoride (50 mg/day) or as monofluorophosphate (200 mg/day or 150 mg/day), or a placebo (146 patients). All patients received daily supplements of 1 g of calcium (Ca) and 800 IU of vitamin D2 (D). A 1-year open follow-up on Ca-D was obtained in 124 patients. After 2 years the fluoride group and the Ca-D group had increased their lumbar BMD by 10.8% and 2.4% respectively (p = 0.0001). However, the rate of patients with at least one new vertebral fracture, defined by semiquantitative assessment and evaluable on an intention-to-treat basis in 89% of patients, was similar in the fluoride groups and the Ca-D group. No difference between the three fluoride regimens was found. The percentage of patients with nonvertebral fractures was not different in the fluoride and Ca-D groups (1.9% and 1.4% respectively for hip fractures). A lower limb pain syndrome occurred more frequently in the fluoride groups. In the 124 patients followed for 1 year after cessation of fluoride therapy, the percentage of patients with at least one new vertebral fracture after 36 months was identical to the percentages in the previous fluoride group and the Ca-D group. We conclude that fluoride-Ca-D regimen was no more effective that Ca-D supplements for the prevention of new vertebral fractures in women with postmenopausal osteoporosis.

Aged↗

[Meloxicam].

NSAID's are currently medications widely prescribed. Meloxicam is a new oxicam which has a low COX-2/COX-1 ratio, i.e. it has an inhibitory effect focused on the inflammatory proteins (COX-2) with relative saving of the homeostatic proteins (COX-1). This molecule has been studied in three rheumatic diseases, the acute flare-up of osteoarthritis, rheumatoïd arthritis, and ankylosing spondylitis. The results show that meloxicam is as effective as comparative NSAID's. A global analysis of the data from more than 5000 patients included in clinical trials showed that gastro-intestinal tolerance of meloxicam was better than that of comparative NSAID'S. Nevertheless, the clinical translation of the anti-COX-2 selectivity concept is currently debated.

Anti-Inflammatory Agents, Non-Steroidal↗

Methotrexate inhibits LPS-induced tumor necrosis factor production in vivo.

We investigated the effects of methotrexate (MTX) on the production of tumor necrosis factor (TNF), nitric oxide (NO) and interleukin-10 (IL-10) in vivo. Administration of low doses of MTX (450 mug/kg once a week for 4 weeks) in Balb/c mice resulted in a significant inhibition of the systemic release of TNF and NO upon LPS challenge, whereas the production of IL-10 remained unchanged. These anti-inflammatory effects of MTX were exerted at the macrophage level since peritoneal macrophages from mice, injected for 4 weeks with MTX produced lower levels of TNF than cells from control mice upon LPS stimulation ex vivo. In parallel, we found that MTX-treated mice were less susceptible to a lethal challenge with LPS and D-galactosamine. MTX did not inhibit TNF release after injection of Concanavalin A (ConA) or anti-CD3 monoclonal antibody (mAb), indicating that MTX does not inhibit TNF production at the T cell level. We conclude that repeated administration of a low dose of MTX in mice is associated with a decreased production of TNF by macrophages upon LPS activation.

Animals↗

Pyogenic arthritis caused by streptococcus equisimilis (group-C streptococcus) in a patient with AIDS.

A patient with the Acquired ImmunoDeficiency Syndrome (AIDS) treated with a daily low dose of corticosteroids for chronic atopic dermatitis experienced a sudden episode of unilateral knee arthritis. Culture of the purulent synovial liquid yielded a pure culture of Streptococcus Equisimilis. A four week period of intravenous antibiotherapy combined with repeated drainages allowed a complete recovery of articular function.

AIDS-Related Opportunistic Infections↗