Mspl restriction fragment length polymorphism near exon 10 of cystic fibrosis (CFTR) gene.

Source/Description: The probe used is a 98 bp fragment amplified by PCR from a cDNA clone of the CFTR gene or from genomic DNA corresponding to exon 10, using two primers from this exon (1)...

A common ancestor DNA motif for invertebrate and vertebrate hormone response elements.

The ecdysone-responsive DNA sequence of the Drosophila hsp27 gene promoter contains four direct and inverted repeats reminiscent of those that compose the vertebrate palindromic estrogen response element (ERE) and the thyroid hormone/retinoic acid response element (TRE/RRE). Interestingly, a 3 bp substitution in the wild-type Hsp27 ecdysone response element (EcdRE) increases both its similarity with the vertebrate ERE and TRE/RRE and its capacity to confer ecdysone responsiveness to a heterologous promoter. Remarkably, increasing the spacing between the inverted repeats of this strong EcdRE by two nucleotides converts it into an ERE. Inversely, decreasing the spacing between the two inverted repeats of the vertebrate consensus palindromic ERE, from three to one nucleotide, converts it into a functional EcdRE. Thus, the only difference between an invertebrate EcdRE and a vertebrate palindromic ERE or TRE/RRE is in the spacing between the conserved inverted repeated motifs forming these palindromic HREs. The finding that the sequence motif 5'-GGTCA-3' present in the vertebrate ERE and TRE/RRE is also a functionally important characteristic of an invertebrate HRE, suggests that a common ancestor regulatory DNA sequence gave rise to all HREs known so far. We discuss the possibility that this progenitor motif is the GGTCA sequence.

Lymphocyte specificity to protein antigens. III. Capacity of low responder mice to beef cytochrome c to respond to a peptide fragment of the molecule.

Lymph node cells derived from A.TH or A.TL mice primed with beef cytochrome c show striking patterns of reactivity when assayed in vitro for antigen-induced T cell proliferation. Whereas cells from A.TH mice respond specifically to beef cytochrome c or peptides composed of amino acids 1-65 and 81-104, cells from A.TL mice respond neither to beef cytochrome c nor to peptide 1-65, but proliferate following exposure to either peptide 81-104 or to a cytochrome c hybrid molecule in which the N-terminal peptide of beef (1-65) was substituted by a similar peptide obtained from rabbit cytochrome c. Thus, T cells from mice phenotypically unresponsive to beef cytochrome may, in fact, contain populations of lymphocytes capable of responding to a unique peptide, the response to which is totally inhibited when the same fragment is presented in the sequence of the intact protein.

Spectral analysis of the luteinizing hormone in the blood samples

Generally, medicine books are concentrated almost exclusively in explaining methodology that analyzes fixed measures, measures done in a certain moment, nevertheless the evolution of the measurement and correct interpretation of the missed values are very important and sometimes can give the key information of the results obtained. Thus, the analysis of the temporary series and spectral analysis or analysis of the time series in the dominion of frequencies can be regarded as an appropriate tool for this kind of studies.In this work the frequency of the pulsating secretion of luteinizing hormone LH (thatregulates the fertile life of women) were analyzed in order to determine the existence of the significant frequencies obtained by analysis of Fourier. Detection of the frequencies, with which the pulsating secretion of the LH takes place, is a quite difficult question due topresence of the random errors in measures and samplings, i.e. that pulsating secretions of small amplitude are not detected and disregarded. In physiology it is accepted that cyclical patterns in the secretion of the LH exist and in the results of this research confirm this pattern and determine its frequency presented in the corresponded periodograms to each of studied cycle. The obtained results can be used as key pattern for future sampling frequencies in order to ¿catch¿ the significant picks of the luteinizing hormone and reflect on time forproductivity treatment of women.

Expression of the NH(2)-terminal fragment of RasGAP in pancreatic beta-cells increases their resistance to stresses and protects mice from diabetes.

OBJECTIVE: Our laboratory has previously established in vitro that a caspase-generated RasGAP NH(2)-terminal moiety, called fragment N, potently protects cells, including insulinomas, from apoptotic stress. We aimed to determine whether fragment N can increase the resistance of pancreatic beta-cells in a physiological setting. RESEARCH DESIGN AND METHODS: A mouse line, called rat insulin promoter (RIP)-N, was generated that bears a transgene containing the rat insulin promoter followed by the cDNA-encoding fragment N. The histology, functionality, and resistance to stress of RIP-N islets were then assessed. RESULTS: Pancreatic beta-cells of RIP-N mice express fragment N, activate Akt, and block nuclear factor kappaB activity without affecting islet cell proliferation or the morphology and cellular composition of islets. Intraperitoneal glucose tolerance tests revealed that RIP-N mice control their glycemia similarly as wild-type mice throughout their lifespan. Moreover, islets isolated from RIP-N mice showed normal glucose-induced insulin secretory capacities. They, however, displayed increased resistance to apoptosis induced by a series of stresses including inflammatory cytokines, fatty acids, and hyperglycemia. RIP-N mice were also protected from multiple low-dose streptozotocin-induced diabetes, and this was associated with reduced in vivo beta-cell apoptosis. CONCLUSIONS: Fragment N efficiently increases the overall resistance of beta-cells to noxious stimuli without interfering with the physiological functions of the cells. Fragment N and the pathway it regulates represent, therefore, a potential target for the development of antidiabetes tools.

Assessment of letrozole and tamoxifen alone and in sequence for postmenopausal women with steroid hormone receptor-positive breast cancer: the BIG 1-98 randomised clinical trial at 8·1 years median follow-up.

BACKGROUND: Postmenopausal women with hormone receptor-positive early breast cancer have persistent, long-term risk of breast-cancer recurrence and death. Therefore, trials assessing endocrine therapies for this patient population need extended follow-up. We present an update of efficacy outcomes in the Breast International Group (BIG) 1-98 study at 8·1 years median follow-up. METHODS: BIG 1-98 is a randomised, phase 3, double-blind trial of postmenopausal women with hormone receptor-positive early breast cancer that compares 5 years of tamoxifen or letrozole monotherapy, or sequential treatment with 2 years of one of these drugs followed by 3 years of the other. Randomisation was done with permuted blocks, and stratified according to the two-arm or four-arm randomisation option, participating institution, and chemotherapy use. Patients, investigators, data managers, and medical reviewers were masked. The primary efficacy endpoint was disease-free survival (events were invasive breast cancer relapse, second primaries [contralateral breast and non-breast], or death without previous cancer event). Secondary endpoints were overall survival, distant recurrence-free interval (DRFI), and breast cancer-free interval (BCFI). The monotherapy comparison included patients randomly assigned to tamoxifen or letrozole for 5 years. In 2005, after a significant disease-free survival benefit was reported for letrozole as compared with tamoxifen, a protocol amendment facilitated the crossover to letrozole of patients who were still receiving tamoxifen alone; Cox models and Kaplan-Meier estimates with inverse probability of censoring weighting (IPCW) are used to account for selective crossover to letrozole of patients (n=619) in the tamoxifen arm. Comparison of sequential treatments to letrozole monotherapy included patients enrolled and randomly assigned to letrozole for 5 years, letrozole for 2 years followed by tamoxifen for 3 years, or tamoxifen for 2 years followed by letrozole for 3 years. Treatment has ended for all patients and detailed safety results for adverse events that occurred during the 5 years of treatment have been reported elsewhere. Follow-up is continuing for those enrolled in the four-arm option. BIG 1-98 is registered at clinicaltrials.govNCT00004205. FINDINGS: 8010 patients were included in the trial, with a median follow-up of 8·1 years (range 0-12·4). 2459 were randomly assigned to monotherapy with tamoxifen for 5 years and 2463 to monotherapy with letrozole for 5 years. In the four-arm option of the trial, 1546 were randomly assigned to letrozole for 5 years, 1548 to tamoxifen for 5 years, 1540 to letrozole for 2 years followed by tamoxifen for 3 years, and 1548 to tamoxifen for 2 years followed by letrozole for 3 years. At a median follow-up of 8·7 years from randomisation (range 0-12·4), letrozole monotherapy was significantly better than tamoxifen, whether by IPCW or intention-to-treat analysis (IPCW disease-free survival HR 0·82 [95% CI 0·74-0·92], overall survival HR 0·79 [0·69-0·90], DRFI HR 0·79 [0·68-0·92], BCFI HR 0·80 [0·70-0·92]; intention-to-treat disease-free survival HR 0·86 [0·78-0·96], overall survival HR 0·87 [0·77-0·999], DRFI HR 0·86 [0·74-0·998], BCFI HR 0·86 [0·76-0·98]). At a median follow-up of 8·0 years from randomisation (range 0-11·2) for the comparison of the sequential groups with letrozole monotherapy, there were no statistically significant differences in any of the four endpoints for either sequence. 8-year intention-to-treat estimates (each with SE ≤1·1%) for letrozole monotherapy, letrozole followed by tamoxifen, and tamoxifen followed by letrozole were 78·6%, 77·8%, 77·3% for disease-free survival; 87·5%, 87·7%, 85·9% for overall survival; 89·9%, 88·7%, 88·1% for DRFI; and 86·1%, 85·3%, 84·3% for BCFI. INTERPRETATION: For postmenopausal women with endocrine-responsive early breast cancer, a reduction in breast cancer recurrence and mortality is obtained by letrozole monotherapy when compared with tamoxifen montherapy. Sequential treatments involving tamoxifen and letrozole do not improve outcome compared with letrozole monotherapy, but might be useful strategies when considering an individual patient's risk of recurrence and treatment tolerability. FUNDING: Novartis, United States National Cancer Institute, International Breast Cancer Study Group.

The nuclear hormone receptor peroxisome proliferator-activated receptor beta/delta potentiates cell chemotactism, polarization, and migration.

After an injury, keratinocytes acquire the plasticity necessary for the reepithelialization of the wound. Here, we identify a novel pathway by which a nuclear hormone receptor, until now better known for its metabolic functions, potentiates cell migration. We show that peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) enhances two phosphatidylinositol 3-kinase-dependent pathways, namely, the Akt and the Rho-GTPase pathways. This PPARbeta/delta activity amplifies the response of keratinocytes to a chemotactic signal, promotes integrin recycling and remodeling of the actin cytoskeleton, and thereby favors cell migration. Using three-dimensional wound reconstructions, we demonstrate that these defects have a strong impact on in vivo skin healing, since PPARbeta/delta-/- mice show an unexpected and rare epithelialization phenotype. Our findings demonstrate that nuclear hormone receptors not only regulate intercellular communication at the organism level but also participate in cell responses to a chemotactic signal. The implications of our findings may be far-reaching, considering that the mechanisms described here are important in many physiological and pathological situations.

Insulin modulation of luteinizing hormone secretion in normal female volunteers and lean polycystic ovary syndrome patients.

BACKGROUND/AIMS: Endocrine features of polycystic ovary syndrome (PCOS) include altered ovarian steroidogenesis, hyperinsulinemia and abnormal luteinizing hormone (LH) secretion. This study was undertaken to further evaluate the role of insulin to modulate LH secretion in lean PCOS patients with normal insulin sensitivity and normal volunteers. METHODS: The study was performed in five nonobese patients diagnosed with PCOS on the basis of amenorrhea and a polycystic morphology at ovarian ultrasound, and 5 normal controls in early to mid-follicular phase and matched for weight and age. All subjects were phenotyped, and then admitted for 12 h of frequent (q 10') blood sampling on two separate occasions, once for a baseline study and the other time for a hyperinsulinemic and euglycemic clamp study. LH was measured in samples obtained throughout each admission in order to perform LH pulse analysis. RESULTS: Baseline LH secretion in PCOS subjects was significantly different from controls: they had higher LH levels, higher LH/FSH ratios as well as a faster LH pulse frequency than normal women. Insulin administration did not affect the pattern of LH secretion of PCOS patients, whereas it significantly increased the LH pulse frequency while decreasing the LH interpulse intervals in the controls. CONCLUSIONS: These data confirm that an abnormal pattern of LH secretion characteristic of PCOS can be observed in lean patients, and appears independent of peripheral insulin levels. Furthermore, our results in lean controls provide the first direct evidence that peripheral insulin can modulate the activity of hypothalamic gonadotropin-releasing hormone (GnRH) neurons in the human.

Fragment de Coran (XXVII, 1 à 3).

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