NANOS-3 and FBF proteins physically interact to control the sperm-oocyte switch in Caenorhabditis elegans.

Background: The Caenorhabditis elegans FBF protein and its Drosophila relative, Pumilio, define a large family of eukaryotic RNA-binding proteins. By binding regulatory elements in the 3' untranslated regions (UTRs) of their cognate RNAs, FBF and Pumilio have key post-transcriptional roles in early developmental decisions. In C.

Systematic analysis of sigma54 N-terminal sequences identifies regions involved in positive and negative regulation of transcription.

The conserved amino-terminal region of sigma 54 (Region I) contains sequences that allow response to activator proteins, and inhibit initiation in the absence of activator. Alanine-scanning mutagenesis has been used to systematically define Region I elements that contribute to each of these functions. Amino acid residues from 6 to 50 were substituted with alanine in groups of three consecutive residues, making a total of 15 mutants.

[Screening for colorectal cancer with an immunological fecal occult blood test].

Unlabelled: Despite worldwide recommendations, the screening for colorectal cancer (CRC) is not routinely performed in our country. Consequently, we conducted a pilot study to evaluate an immunological fecal occult blood test (FOBT).

Methods: We studied 332 average-risk patients (age over 50 years, asymptomatic, with no personal or family history of CRC) who consulted primary care-generalists from Buenos Aires.

Functions of the sigma(54) region I in trans and implications for transcription activation.

Control of transcription frequently involves the direct interaction of activators with RNA polymerase. In bacteria, the formation of stable open promoter complexes by the sigma(54) RNA polymerase is critically dependent on sigma(54) amino Region I sequences. Their presence correlates with activator dependence, and removal allows the holoenzyme to engage productively with melted DNA independently of the activator.

[Mental health and pregnancy in adolescence. Pregnancy context and early biographical consequences].

Background: Pregnant adolescents have a higher risk of complications of pregnancy and labor. There is also a higher risk of child abuse and neglect among this age group.

Aim: To study the psychological and social context, biographical impact and the prevalence of mental disorders among pregnant teenagers.

Involvement of the sigmaN DNA-binding domain in open complex formation.

sigmaN (sigma54) RNA polymerase holoenzyme closed complexes isomerize to open complexes in a reaction requiring nucleoside triphosphate hydrolysis by enhancer binding activator proteins. Here, we characterize Klebsiella pneumoniae sigmaN mutants, altered in the carboxy DNA-binding domain (F354A/F355A, F402A, F403A and F402A/F403A), that fail in activator-dependent transcription. The mutant holoenzymes have altered activator-dependent interactions with promoter sequences that normally become melted.

Sequences in sigmaN determining holoenzyme formation and properties.

Sigma subunits of bacterial RNA polymerases are closely involved in many steps of promoter-specific transcription initiation. Holoenzyme formed with the specialised minor sigma-N (sigmaN) protein binds rare promoters in a transcriptionally inactive state and functions in enhancer-dependent transcription. Using competition and dissociation assays, we show that sigmaN-holoenzyme has a stability comparable to the major sigma70-holoenzyme.

The XylS-dependent Pm promoter is transcribed in vivo by RNA polymerase with sigma 32 or sigma 38 depending on the growth phase.

The Pm promoter of the TOL plasmid of Pseudomonas putida is expressed at high level along the growth curve. This transcription is dependent on the positive regulator XylS activated by 3-methylbenzoate. The sigma factor sigma 38 is required for expression in early stationary phase and thereafter.

Effect of fentanyl and naloxone on a thalamic induced painful response in intractable epileptic patients.

Acute high-frequency (60/s) high-intensity (2,100-2,300 microA) stimulation of the mesial, caudal and inferior portion of the centromedian thalamic region within or close to the parafascicular nucleus produced a sharp, intense, cramp-like painful response localized to the face and shoulder (medial stimulation) or arm and hand (lateral stimulation) contralateral to the stimulation site in 4 intractable epileptic patients in whom depth electrodes had been implanted as a part of a neuroaugmentive procedure for seizure control. This thalamic induced painful response was always accompanied by objective clinical signs (facial gesticulation and contraction of the corresponding muscles) during thalamic stimulation and significant increments in EEG, EKG and respiratory frequencies and EMG muscular tonus from 10 s before to 10 s after thalamic stimulation. Opioid agonists (fentanyl 5.

[Immunohistochemical tumor markers in infiltrating ductal breast carcinoma].

Background: Immunohistochemical techniques allow the study of tumoral markers with predictive or prognostic value.

Aim: To study tumoral markers in mammary carcinoma and to relate these markers with age and tumoral histological grade.

Material And Methods: The expression of nuclear estrogen receptor (RE), nuclear progesterone receptor (PGR), p53 and c-erb-B2 proteins was analyzed in 382 cases of infiltrating ductal carcinoma of the breast.

Amino-terminal sequences of sigmaN (sigma54) inhibit RNA polymerase isomerization.

In bacteria, association of the specialized sigmaN protein with the core RNA polymerase subunits forms a holoenzyme able to bind promoter DNA, but unable to melt DNA and initiate transcription unless acted on by an activator protein. The conserved amino-terminal 50 amino acids of sigmaN (Region I) are required for the response to activators. We have used pre-melted DNA templates, in which the template strand is unpaired and accessible for transcription initiation, to mimic a naturally melted promoter and explore the function of Region I.

Critical nucleotides in the upstream region of the XylS-dependent TOL meta-cleavage pathway operon promoter as deduced from analysis of mutants.

The Pm promoter, dependent on TOL plasmid XylS regulator, which is activated by benzoate effectors, drives transcription of the meta-cleavage pathway for the metabolism of alkylbenzoates. This promoter is unique in that in vivo transcription is mediated by RNA-polymerase with different sigma factors. In vivo footprinting analysis shows that XylS interacted with nucleotides in the -40 to -70 region.

Repression by the 3' UTR of fem-3, a sex-determining gene, relies on a ubiquitous mog-dependent control in Caenorhabditis elegans.

The fem-3 sex-determining gene is repressed post-transcriptionally via a regulatory element in its 3' untranslated region (UTR) to achieve the switch from spermatogenesis to oogenesis in the Caenorhabditis elegans hermaphrodite germ line. In this paper, we investigate the fem-3 3' UTR control in somatic tissues using transgenic reporter assays, and we also identify six genes essential for this control. First, we find that a reporter transgene bearing a wild-type fem-3 3' UTR is repressed in somatic tissues, whereas one bearing a mutant fem-3 3' UTR is derepressed.

A systematic, one-stage approach in the treatment of tuberous breast deformity.

During a 2-year period, we performed a single-stage procedure on 7 patients with unilateral "tuberous" breasts after thorough analysis of the deformity and the contralateral breast. Deficient breast envelope skin was replaced by use of a laterally based random inframammary cutaneous flap. Breast tissue rearrangement with or without augmentation was required to address the parenchymal maldistribution and volume abnormalities.

Activation and repression of transcription at the double tandem divergent promoters for the xylR and xylS genes of the TOL plasmid of Pseudomonas putida.

The xylR and xylS genes are divergent and control transcription of the TOL plasmid catabolic pathways for toluene metabolism. Four promoters are found in the 300-bp intergenic region: Pr1 and Pr2 are constitutive sigma70-dependent tandem promoters that drive expression of xylR, while expression of the xylS gene is driven from Ps2, a constitutive sigma70-dependent promoter, and by the regulatable sigma54 class Ps1 promoter. In Ps1 the XylR targets (upstream activator sequences [UASs]) overlap the Pr promoters, and two sites for integration host factor (IHF) binding are located at the region from positions -2 to -30 (-2/-30 region) and the -137/-156 region, the latter overlapping the Pr promoters.

Clinical, morphological and biochemical features in the familial articular hypermobility syndrome (FAHS): a family study.

A female with clinical features of familial articular hypermobility syndrome (FAHS) and her family were studied. The subject showed generalized hypermobility, except for a painful shoulder which presented functional limitation with a diagnosis of painful shoulder syndrome. Biochemical studies demonstrated that collagen and glycosaminoglycans (GAGs) contents from skin biopsies of the subject and her family were almost normal.

Arac/XylS family of transcriptional regulators.

The ArC/XylS family of prokaryotic positive transcriptional regulators includes more than 100 proteins and polypeptides derived from open reading frames translated from DNA sequences. Members of this family are widely distributed and have been found in the gamma subgroup of the proteobacteria, low- and high-G + C-content gram-positive bacteria, and cyanobacteria. These proteins are defined by a profile that can be accessed from PROSITE PS01124.

A conserved RNA-binding protein that regulates sexual fates in the C. elegans hermaphrodite germ line.

The nematode Caenorhabditis elegans has two sexes, males and hermaphrodites. Hermaphrodites Initially produce sperm but switch to producing oocytes. This switch appears to be controlled by the 3' untranslated region of fem-3 messenger RNA.

Transcriptional control of the multiple catabolic pathways encoded on the TOL plasmid pWW53 of Pseudomonas putida MT53.

The TOL plasmid pWW53 encodes a catabolic pathway for the metabolism of toluene. It bears an upper-pathway operon for the oxidation of toluene to benzoate and a copy of the gene that encodes regulatory protein XylR. For metabolism of the aromatic carboxylic acid, it bears two functional homologous meta-pathway operons, together with two functional copies of the xylS regulatory gene (xylS1 and xylS3).

[Cervical polyadenopathy due to Kikuchi and Fujimoto disease].

Kikuchi and Fujimoto disease is a benign subacute necrotizing lymphadenitis, probably associated to a viral infection, that affects mostly young Asian women. We report a 19 years old women, with a vast familiar history of thyroid disease (three uncles with papillary thyroid carcinoma and one with a Hashimoto thyroiditis). After an upper respiratory infection, she presented with painless cervical adenopathies.

[Cytodiagnosis of focal hepatic lesions by image guided fine needle biopsy].

Background: Image guided fine needle cytological diagnosis of hepatic lesions has become a routine diagnostic procedure.

Aim: To analyze the diagnostic yield of fine needle cytological aspirates of the liver.

Patients And Methods: Two hundred two aspirates, obtained in 201 patients were studied.

The TACAN4TGCA motif upstream from the -35 region in the sigma70-sigmaS-dependent Pm promoter of the TOL plasmid is the minimum DNA segment required for transcription stimulation by XylS regulators.

Transcription from the TOL plasmid meta-cleavage pathway operon promoter Pm is dependent on the XylS regulator activated by benzoate effectors or after XylS overproduction. We have generated 5' deletions in Pm and have analyzed expression from wild-type and mutant promoters with the wild-type XylS regulator and XylS mutant regulators that stimulated transcription constitutively. We have found that the motifs T(C or A)CAN4TGCA located between -46 and -57 and -67 and -78 with respect to the main transcription initiation point are required for maximal stimulation of transcription from Pm with effector-activated wild-type XylS.

Expression of the TOL plasmid xylS gene in Pseudomonas putida occurs from a alpha 70-dependent promoter or from alpha 70- and alpha 54-dependent tandem promoters according to the compound used for growth.

Growth of Pseudomonas putida (pWWO) on alkylbenzoates requires the expression of the meta pathway operon, which is mediated by the XylS protein after binding of a benzoate effector. Alternatively, in cells growing on toluene or its aromatic alcohols, overexpression of xylS mediated by XylR activated by these compounds leads to overproduction of the XylS regulator, which even in the absence of benzoate effectors stimulates transcription from the meta cleavage pathway operon promoter. We show here that in bacteria growing on glycerol or alkylbenzoates, the xylS gene is expressed at a low but constitutive level from a newly found sigma 70-dependent promoter called Ps2.

Role of sigma S in transcription from the positively controlled Pm promoter of the TOL plasmid of Pseudomonas putida.

Transcription from the TOL plasmid Pm promoter is dependent on the XylS regulator activated by benzoate effectors. We analysed transcription from Pm in several backgrounds with differing Escherichia coli alpha and sigma subunits of RNA polymerase. In different RpoA backgrounds, transcription from Pm was as high as in the wild-type background throughout the growth curve.