Characteristics of separated epithelial and stromal subfractions of prostate: I. Rat ventral prostate

These studies were initiated with the objective of isolating epithelial and stromal cells of human prostatic tissue in undamaged state, in order to study the cellular distribution of steroid receptors in benign prostatic hyperplasia (BPH) relative to normal prostate. Initial experiments showed that when BPH tissue immersed in tissue culture media was progressively fragmented by various cutting procedures, epithelial elements were selectively released as clumps of variable size and individual cells, but that a large percentage of these cells were damaged, as evidenced by their failure to exclude trypan blue (TB). These observations suggested that if tissue fragmentation were carried out under defined conditions that minimize cell damage, BPH subfractions might be obtained containing a large percentage of undamaged cells. To determine conditions of tissue fragmentation which result in maximal recovery of epithelial cells which exclude TB, rat ventral prostate (RVP) was chosen as a model system. Experiments with RVP revealed that maximal yields of such cells were obtained in "large" epithelial clumps (greater than 30 cells per clump) released under the following conditions: (1) chopping the tissue with razor blades in a large volume (2 ml/100 mg RVP) of a Ca2+-free tissue culture medium ( Joklik 's-MEM) containing 1% casein, (2) carrying out the entire fractionation procedure in the cold, and (3) maintaining a 1% casein concentration in the medium during chopping, as well as in subsequent washing procedures, to protect cells from proteolytic activity. In large epithelial clumps, cells in the interior of the clump were not stained by TB but the cells at the periphery of the clump were freely permeable to TB. Single epithelial cells and small epithelial clumps (3-10 cells) released by razor blade fragmentation were also permeable to TB. When large epithelial clumps were incubated at 20 degrees C for 90 min, the clumps disaggregated into smaller clumps and morphologically intact single cells, which did not exclude TB. The residual tissue fragments remaining after chopping contained the bulk of stromal cells plus some epithelial elements. The latter could be removed by gentle rubbing of the fragments on a sieve in the presence of medium. The stromal fraction thus obtained consisted of stromal cells, embedded in mesenchymal matrix, which were not stained by TB and appeared normal when examined histologically by light microscopy.(ABSTRACT TRUNCATED AT 400 WORDS)     

A mouse mutant strain highly resistant to methyl β-carboline-3-carboxylate-induced seizures

The convulsant properties of methyl -carboline-3-carboxylate (-CCM) were evaluated in the TaT-fm/Gnc ^Ta+/+Tfm strain carrying the tabby coat color (Ta) and/or the testicular feminization (Tfm) gene. When injected intraperitoneally within a 5–60 mg/kg dose range, -CCM-induced convulsions in less than 25% of the mice, thus providing evidence for a high resistance of this strain, as compared to classical strains of mice. However, this strain responds normally to the convulsant pentylenetetrazol (PTZ), suggesting a specific resistance to -CCM. Both the Ta gene and the TaTfm/Gnc genetic background were involved in the high resistance to -CCM. In addition, concentrations of neurosteroids and benzodiazepine binding, both modulating GABA_A receptor efficacy, have been measured in order to elucidate the biological mechanisms of drug resistance.     

Expression of the neuroendocrine phenotype in carcinomas of the breast

Neuroendocrine (NE) features are detectable in carcinomas of the breast either as scattered cells immunoreactive for NE markers in carcinoma of the usual type (NOS), or as special type of tumors where the vast majority of the cells display NE characteristics. The former type of lesions, whose biological and diagnostic significance is not clear yet, might reproduce the same phenomenon known to occur in carcinomas of the gastrointestinal tract and pancreas. In the present review we focus on the latter type of lesions, a spectrum of breast tumors largely composed of NE cells. These carcinomas, that we consider the "NE differentiated carcinomas of the breast," are here distinguished from "breast carcinomas NOS with NE differentiation." The diagnostic and histogenetic features of the various types of "NE differentiated carcinomas of the breast," their histological and cytological features and the role and value of ancillary diagnostic techniques, are reviewed. Data of the literature are discussed and related to a relatively large personal series. In addition, divergent differentiation in NE carcinomas of the breast, which is a relatively frequent phenomenon of diagnostic interest but of unknown significance (mainly involving mucinous intra- and extracellular production) is discussed.     

Oxytocin and oxytocin-analogue F314 inhibit cell proliferation and tumor growth of rat and mouse mammary carcinomas

The effects of oxytocin (OT) and the OT-analogue F314 were investigated on xenografts of mouse mammary and colon carcinomas (TS/A and C26 tumors) and of rat mammary carcinoma (D-R3230AC). In all cases, proliferation was previously assessed by cell counting in cultured cell lines, whereas tumor growth was checked by serial measures of tumor volume and by evaluation of tumor weight at the end of the experiment. Both cell proliferation and tumor growth were inhibited by OT and F314. These data support previous observations on the inhibitory effect of OT and F314 on the growth of MCF7, T47D and MDA-MB231 human breast cancer cell lines and open new prospects for testing the effect of this hypothalamic hormone and its analogues on the control of breast carcinoma growth. © 1996 Wiley-Liss, Inc.     

Validation of an analytical procedure to measure trace amounts of neurosteroids in brain tissue by gas chromatography-mass spectrometry

A selective and extremely sensitive procedure has been developed and optimized, using high-performance liquid chromatography (HPLC), specific derivatization and gas chromatography-mass spectrometry (GC-MS), to simultaneously quantify very small amounts of different neurosteroids from rat brain. Unconjugated and sulfated steroids in brain extracts were separated by solid-phase extraction. The unconjugated fraction was further purified by HPLC, the steroids being collected in a single fraction, and the sulfated fraction was solvolyzed. All steroids were derivatized with heptafluorobutyric acid anhydride and analyzed by GC-MS (electron impact ionization) using selected-ion monitoring. High sensitivity and accuracy were obtained for all steroids. The detection limits were 1 pg for pregnenolone (PREG), dehydroepiandrosterone (DHEA) and their sulfate esters PREG-S and DHEA-S, 2 pg for progesterone (PROG) and 5 pg for 3alpha,5alpha-tetrahydroprogesterone (3alpha,5alpha-THP). In a pilot study on a rat brain, the concentrations of PREG-S and DHEA-S were 8.26+/-0.80 and 2.47+/-0.27 ng/g, respectively. Those of PREG, DHEA and PROG were 4.17+/-0.22, 0.45+/-0.02 and 1.95+/-0.10 ng/g, respectively. Good linearity and accuracy were observed for each steroid. The methodology validated here, allows femtomoles of neurosteroids, including the sulfates, found in small brain samples (at least equal to 10 mg) to be quantified simultaneously.     

Confocal microscope analysis and tridimensional reconstruction of papillary thyroid carcinoma nuclei

Nuclei of papillary thyroid carcinoma (PTC) are characterised by diagnostic morphological features, which include optically clear nuclei, irregular nuclear profile, pseudoinclusions and grooves. In the present study, such nuclear features were analysed by means of confocal microscopy using anti-lamin B antibodies to outline the nuclear membrane. Parallel sections of the nucleus, produced by confocal microscope analysis, showed that the nuclear shape is markedly irregular with profound invaginations, clefts and tunnel-like structures, which correspond to the grooves and holes detectable using light microscopy, respectively. A tridimensional (3-D) model of the nuclei, obtained by a computer-based reconstruction of confocal microscope images, showed, in the vast majority of PTC cells, nuclei with crateriform areas, clefts and even tunnel-like structures piercing the whole nuclear thickness. By rotating these models in space, it became evident that the holes and grooves seen in light microscopy correspond to invaginations and tunnels, depending on the viewpoint. In conclusion, this is the first application of confocal microscopy and tridimensional reconstruction to the study of nuclear morphology of PTC and of tumours in general. The light microscopic appearance of PTC nuclei, so familiar to pathologists, is, therefore, due to profound remodelling of the nuclear shape with invaginations and tunnels, which appear as either grooves or holes, according to the viewpoint.     

Mapreg

MAPREG (microtubule-associated protein/neurosteroidal pregnenolone) is a start-up company that was created in October 2000. Its acronym recalls the basic discovery (Murakami et al., 2000) from which drug(s) will hopefully be developed that are useful for neuroprotection and repair in conditions such as post-traumatic and postischemic lesions, as well as defects proper to normal aging and neurodegenerative diseases, that is, principally Alzheimer’s disease. Pregnenolone, the main steroid synthesized from cholesterol in the nervous system (therefore, a neurosteroid), binds specifically with high affinity (≥40 nM) to microtubule-associated protein 2 (MAP2), a protein family involved in the assembly and stabilization of microtubules made from tubulin α and β polymers, and in the bundling of several microtubules by MAP2 projection arms. Pregnenolone binding increases MAP2-induced microtubule polymerization, when purified tubulin and MAP2 are coincubated in GTP containing buffer at 37°C. Therefore, MAP2 can be considered as a receptor for a novel mechanism of steroid action. The underlying principle and its potential pharmacological consequences are described in an INSERM patent (FR 0003430; March 17, 2000) (see Fig. 1). MAPREG has established its own laboratory in a space rented to Bicêtre hospital, near the research building of INSERM, where two of the main founders of the company (Drs. E. Baulieu and P. Robel) work. The company has been quite successful, largely thanks to the support of ISOA (attributed in October 2002). A lead compound (pregnenolone derivative) was tested and patented by MAPREG early in 2003 (FR 0300507; January 17, 2003). Activities and results reported at the ISOA meeting on Oct. 2, 2003, include in vitro basic studies, in vitro and in vivo neuroprotection trials in rodent systems, and studies with human cells and an AD transgenic mouse model.     

Administration of diethylstilbestrol during pregnancy, a public health problem

The analysis of the health risks associated with the administration of diethylstilbestrol (DES) during pregnancy (for the prevention or treatment of threatened abortions) has been largely published. Concerning mothers, a relationship between DES exposure during pregnancy and risk of cancer is unproved. However, existing studies are sufficient cause for serious concern over drug's carcinogenic potential, and further follow-up studies are required. Concerning daughters, a clear association between in utero exposure to DES and clear cell adenocarcinoma of the vagina or cervix is established (incidence between 0.14 and 1.4 per 1000 through age 24). The risk for squamous cell cancer of the vagina and cervix does not seem to be increased. Cervico-vaginal adenosis is frequent (20% to 60% of exposed subjects). This is not a pre-cancerous lesion, its spontaneous evolution is towards regression. No treatment is prescribed. Morphological changes of the genital tract have been described, their consequences on fertility and pregnancy are not clear. Concerning sons, an excess of genital abnormalities (especially of the epididymis and undescended testis) has been reported, but information on the fertility implications of these findings is not available. There is no evidence of an increased risk of testicular cancer. The analysis of all these informations should allow to bring up a policy to take into account these risks in the population.     

Impairment of glucose tolerance in yellow (Avy/A) (BALB/c X VY) F-1 hybrid mice by hyperglycemic peptide(s) from human pituitary glands

A fraction of human pituitary extract containing low molecular weight peptide(s) was found to impair glucose tolerance in obese yellow (Avy/A) (BALB/c X VY) F-1 hybrid female mice. In these mice, purified human GH was not hyperglycemic. Glucose tolerance of untreated yellow mice was somewhat less impaired than that of untreated ob/ob mice, and priming with dexamethasone was not required to elicit impairment of glucose tolerance. The lean agouti (A/a) littermates of the yellow mice did not respond to the hyperglycemic peptide(s), suggesting that an insulin-resistant animal is required for assay of the pituitary hyperglycemic peptide(s). Plasma insulin levels of the obese yellow mice treated with the hyperglycemic peptide(s) were significantly decreased compared to those of saline-treated controls. No decrease in plasma insulin was observed in the similarly treated lean agouti mice. The study demonstrated that the yellow Avy/A (BALB/c X VY) F-1 hybrid mouse is a suitable animal for investigation of the physiological mechanism of action of the pituitary hyperglycemic peptide(s).