Stable ciliary activity in human nasal epithelial cells grown in a perfusion system.

PURPOSE: Explore the usefulness of a perfusion system in order to establish human nasal epithelial cell cultures suitable for long-term in vitro ciliary beat frequency (CBF) and cilio-toxicity studies. METHODS: The cells were obtained by protease digestion of nasal biopsy material. The cells were plated at a density of 0.8-1 x 10(6)/cm2 on Vitrogen-coated polyethylene terephthalate membranes, and cultured under submerged conditions in a CO2 incubator or in a perfusion system (initiated on days 8-9 after plating). The CBF was determined at 24.1 +/- 0.8 degrees C by a computerized microscope photometry system. The morphology of the cultured cells was characterized by transmission electron microscopy (TEM). RESULTS: Under CO2 incubator culture conditions, stable ciliary activity was expressed and maintained from day 2 to day 24. Under perfusion system culture conditions, the CBF (mean+/-S.D., n = 4) amounted to 8.4 +/- 0.9 and 8.8 +/- 0.4 Hz on days 7 and 14, respectively. These values were lower as compared to the corresponding CBF obtained in the CO2 incubator cultures (9.5 +/- 0.6 and 9.9 +/- 1.0 Hz, respectively). Reference cilio-stimulatory (glycocholate) and cilio-inhibitory (chlorocresol) compounds were used to assess CBF reactivity. In the CO2 incubator and 7- and 14-days perfusion system cultures, glycocholate (0.5%) showed a reversible cilio-stimulatory effect of 23, 26 and 21%, respectively, while chlorocresol (0.005%) exerted a reversible cilio-inhibitory effect of 36, 40 and 36%, respectively. TEM revealed polarized cuboidal to columnar epithelial morphology, with well-differentiated ciliated cells under CO2 and perfusion system conditions (up to day 23). CONCLUSION: Culturing human nasal epithelial cells on Vitrogen-coated polyethylene terephthalate membranes in submerged conditions in a CO2 incubator and in a perfusion system offers the possibility for long-term preservation (up to 22-24 days) of stable and reactive CBF in vitro.

Non Hodgkin's lymphoma involving the adrenal glands and the central nervous system (CNS): a particular evolution after chemotherapy.

Adrenal lymphoma is extremely rare. The prognostic depends on involvement of other organs (such as the central nervous system) responsible for lower median survival. We report the case of a 51-year-old man with non Hodgkin's Diffuse Large B Cell Lymphoma (DLBCL) involving the central nervous system (CNS) and the adrenal glands simultaneously. The endocrine exploration revealed a partial adrenal insufficiency and ruled out a pheochromocytoma. Computerized tomographic (CT) scan directed needle biopsy of the adrenal gland allowed the diagnostic of non-Hodgkin lymphoma (NHL). CNS biopsies showed similar histopathologic lesions. After aggressive polychemotherapy and methotrexate intrathecal injection, a dissociated therapeutic response was observed with a decrease of the cerebral lesion and an increase of the adrenal mass. This result may be explained by the efficacy of corticosteroid therapy on cerebral edema. The prognosis was poor with tumor infiltration of the leptomeninges and death 16 months after diagnosis.

[Pre-toxic adrenocortical adenoma ("pre-Cushing syndrome"): role of 17-hydroxyprogesterone dosage under ACTH analog stimulation. Apropos of a case]. / Adénome surrénalien pré-toxique ("syndrome de pré-Cushing"): intérêt du dosage de la 17-hydroxyprogestérone sous stimulation par analogue de l'ACTH a propos d'un cas.

We report on a case of a 63-year-old male patient who presented with an adrenal incidentaloma corresponding to a pre-toxic adrenocortical adenoma ("pre-Cushing's syndrome"). Nycthemeral cortisol cycle and free urinary cortisol were within the normal range. Basal ACTH and dehydroepiandrosterone sulfate levels were decreased and the 17-hydroxyprogesterone (17OHP) response under ACTH stimulation (tetracosactide) was increased. The ACTh test appears mandatory in the incidentaloma work-up to order to identify the pre-toxic adenomas. Its elevation reflects likely intra-tumoral enzymatic defects. Pre-Cushing's syndrome therapeutic management is still debated. No surgery was performed in our patient. A 3-year follow-up did not show overt Cushing's syndrome features.

[Suppressive hormone therapy for thyroid nodules. Prospective evaluation. Preliminary results]. / Hormonothérapie freinatrice pour nodule thyroïdien. Evaluation prospective. Résultats préliminaires.

The benefit of thyroid hormone for patients with thyroid nodule is still controversial. Suppressive therapy is not useful to distinguish benign or malignant tumors, since some malignant nodules become smaller and most benign nodules do not shrink with thyroid hormone therapy. A prospective evaluation was conducted by the french Groupe de Recherche sur la Thyroïde on 123 patients with solitary nodules : ultrasonographic volume of the nodules regressed from 2.76 to 2.39 ml with suppressive doses of levothyroxine for 18 months, while a progression from 3.6 to 4.1 ml was seen for patients with placebo. The benefit of the suppressive therapy was also obvious on the micronodular dystrophy detected by ultrasonography. No side effects were seen in treated patients. These preliminary results argue for the benefit of suppressive therapy, as suggested by meta-analysis of the published randomized trials.

Activating mutations of TSH receptor.

Mechanisms of activation of G protein-coupled receptor by the agonist, are supposed to rely on release from structural constraints, then allowing the "relaxed" receptor to activate the G protein. By analogy with experimental works on alpha1b adrenergic receptor, showing that mutations could result in constitutive activation of the receptor, it was hypothezised, that similar but spontaneous somatic mutations of the Thyrotropin-receptor could be the cause of thyroid toxic adenomas. This hypothesis has been confirmed. Furthermore, the rare cases of familial non autoimmune hyperthyroidism have been shown to be caused by germline mutations of Thyrotropin receptor, as well as the cases of non autoimmune neonatal hyperthyroidism. Beside the constitutive activation of the Thyrotropin-receptor a case of sensitization of the Thyrotropin-receptor to hCG by a mutation in the extracellular domain has been identified as the cause of familial gestational hyperthyroidism. All those mutation studies have been helpful in understanding the mechanisms of activation of glycoproteic hormones. A first model had been proposed, according to datas obtained from these mutations. In this model, the extracellular domain of the receptor exerts an inhibitory action on the transmembrane domain, and this interaction has to be disrupted to allow for activation of the receptor. However, recent experimental datas suggest that interaction between extracellular domain and transmembrane domain are more complex than just inhibitory, and that upon activation, the extracellular domain may convert from an inhibitory structure to an activating one.

Cell cycle regulated expression of NCoR might control cyclic expression of androgen responsive genes in an immortalized prostate cell line.

In this work we have studied the mechanisms of regulation of expression of androgen receptor (AR) target genes. We have used an immortalized non-tumorigenic prostate cell line RWPE-1-AR(tag) constitutively expressing an exogenous AR as a model. We observed that all studied AR target genes exhibited a specific expression during the G1 phase of the cell cycle despite the constitutive expression of AR. Importantly, we found that the expression of NCoR, an AR co-repressor, was downregulated during the G1 phase and expressed as mRNA and protein specifically during the S phase. The role of NCoR in repressing androgen-induced expression of AR target genes in S phase was further demonstrated by altering expression of NCoR during the cell cycle through knockdown or induced overexpression. Using two alternative techniques we show that AR binds directly to target DNA in the chromatin only during the G1 phase. These data support the hypothesis that NCoR might control a cell cycle dependent regulation of expression AR target genes in prostate cells.