RNA polymerase II CTD S2P is dispensable for embryogenesis but mediates exit from developmental diapause in C. elegans.

Serine 2 phosphorylation (S2P) within the CTD of RNA polymerase II is considered a Cdk9/Cdk12-dependent mark required for 3'-end processing. However, the relevance of CTD S2P in metazoan development is unknown. We show that cdk-12 lesions or a full-length CTD S2A substitution results in an identical phenotype in Caenorhabditis elegans Embryogenesis occurs in the complete absence of S2P, but the hatched larvae arrest development, mimicking the diapause induced when hatching occurs in the absence of food. Genome-wide analyses indicate that when CTD S2P is inhibited, only a subset of growth-related genes is not properly expressed. These genes correspond to SL2 trans-spliced mRNAs located in position 2 and over within operons. We show that CDK-12 is required for maximal occupancy of cleavage stimulatory factor necessary for SL2 trans-splicing. We propose that CTD S2P functions as a gene-specific signaling mark ensuring the nutritional control of the C. elegans developmental program.

'Frequently recurring' nocturnal polyuria is predictive of response to desmopressin in monosymptomatic nocturnal enuresis in childhood.

INTRODUCTION: The nocturnal polyuria is considered a significant predictive value for response to desmopressin. The cutoff value useful to define nocturnal polyuria is still a matter of debate. Moreover, it is current notion that maximal voided volume (MVV) could be used as a predictor for desmopressin response. OBJECTIVE: The objective of this study was to assess the impact of different definitions of nocturnal polyuria (and of its frequency) and MVV in predicting the response to desmopressin. STUDY DESIGN: A total of 103 patients with frequent monosymptomatic nocturnal enuresis (≥4 wet nights/week) were enrolled. A bladder diary over a 4-day period was collected. The MVV was defined as the highest micturition volume detected at bladder diary. Nocturnal diuresis was measured in 5 wet nights. Then, patients were administered with 120 mcg of sublingual desmopressin. After 2 months, if there was no complete response, the dose was increased to 240 mcg. Nocturnal polyuria was defined as follows: 1.Definition 1: nocturnal urine production >130% of the expected bladder capacity (EBC). 2. Definition 2: >100% EBC. 3. Definition 3: > 20×(age + 9) mL. The primary outcome was 'response to desmopressin' after 3 months of treatment. RESULTS: Fifty-three patients responded to desmopressin. Comparing the responses to desmopressin on the basis of the three definitions of nocturnal polyuria, no significant difference was found. There was no cutoff value of nocturnal polyuria expressed as %EBC useful in providing a significant receiver-operating characteristic (ROC) curve. The area under the ROC curve for MVV expressed as %EBC was 0.67 (95% confidence interval [CI], 0.54-0.80; p = 0.01). A MVV >103.1% of EBC had 78.8% (95% CI, 61.1-91.0) sensitivity and 47.5% (95% CI, 31.5-63.9) specificity for predicting response to desmopressin. Among the patients with nocturnal polyuria according to definition 1, a higher percentage of subjects with nocturnal polyuria in 4 out of 5 or 5 out of 5 nights responded to desmopressin, compared with other patients. Patients presenting with nocturnal polyuria according to definition 3 in 5 out of 5 nights showed a 100% of response to desmopressin. At multivariate analysis, the only significant odds ratio (OR) to respond to desmopressin was that of patients with nocturnal polyuria according to definition 1 in >3 nights (OR = 7.1, 95% CI, 1.3-40.3). DISCUSSION AND CONCLUSIONS: The presence or absence of nocturnal polyuria-according to all three definitions-in at least one night was not effective in predicting the response to desmopressin. Predictors of desmopressin response were nocturnal polyuria in >3 out of 5 wet nights according to definition 1 and in 5 out of 5 wet nights according to definition 3.

The C. elegans SET-2/SET1 histone H3 Lys4 (H3K4) methyltransferase preserves genome stability in the germline.

Maintaining the integrity of genetic information across generations is essential for both cell survival and reproduction, and requires the timely repair of DNA damage. Histone-modifying enzymes play a central role in the DNA repair process through the deposition and removal of post-translational modifications on the histone tails. Specific histone modification act in the DNA repair process through the recruitment of proteins and complexes with specific enzymatic activities, or by altering the chromatin state at the site of DNA lesions. The conserved SET1/MLL family of histone methyltransferases (HMT) catalyzes methylation of histone H3 on Lysine 4 (H3K4), a histone modification universally associated with actively transcribed genes. Studies have focused on the role of SET1/MLL proteins in epigenetic regulation of gene expression. Much less is known on their role in the DNA repair process in a developmental context. Here we show that SET-2, the Caenorhabditis elegans orthologue of SET1, is required to preserve germline genome integrity over subsequent generations. Animals lacking the SET-2 catalytic subunit show a transgenerational increase in sensitivity to DNA damage-inducing agents that is accompanied by a defect in double-strand break (DSB) repair and chromosome fragmentation. These defects are not due to a failure to activate the DNA damage response (DDR) that allows detection, signaling and repair of DNA lesions, because cell cycle arrest and apoptosis, key components of this pathway, are efficiently induced in set-2 mutant animal. Rather, our results suggest that SET-2 plays a role in the transgenerational maintenance of genome stability by acting in DNA repair downstream of DDR signaling.

Adaptive preconditioning in neurological diseases - therapeutic insights from proteostatic perturbations.

In neurological disorders, both acute and chronic neural stress can disrupt cellular proteostasis, resulting in the generation of pathological protein. However in most cases, neurons adapt to these proteostatic perturbations by activating a range of cellular protective and repair responses, thus maintaining cell function. These interconnected adaptive mechanisms comprise a 'proteostasis network' and include the unfolded protein response, the ubiquitin proteasome system and autophagy. Interestingly, several recent studies have shown that these adaptive responses can be stimulated by preconditioning treatments, which confer resistance to a subsequent toxic challenge - the phenomenon known as hormesis. In this review we discuss the impact of adaptive stress responses stimulated in diverse human neuropathologies including Parkinson׳s disease, Wolfram syndrome, brain ischemia, and brain cancer. Further, we examine how these responses and the molecular pathways they recruit might be exploited for therapeutic gain. This article is part of a Special Issue entitled SI:ER stress.

Antagonistic functions of SET-2/SET1 and HPL/HP1 proteins in C. elegans development.

Cellular identity during metazoan development is maintained by epigenetic modifications of chromatin structure brought about by the activity of specific proteins which mediate histone variant incorporation, histone modifications, and nucleosome remodeling. HP1 proteins directly influence gene expression by modifying chromatin structure. We previously showed that the Caenorhabditis elegans HP1 proteins HPL-1 and HPL-2 are required for several aspects of post-embryonic development. To gain insight into how HPL proteins influence gene expression in a developmental context, we carried out a candidate RNAi screen to identify suppressors of hpl-1 and hpl-2 phenotypes. We identified SET-2, the homologue of yeast and mammalian SET1, as an antagonist of HPL-1 and HPL-2 activity in growth and somatic gonad development. Yeast Set1 and its mammalian counterparts SET1/MLL are H3 lysine 4 (H3K4) histone methyltransferases associated with gene activation as part of large multisubunit complexes. We show that the nematode counterparts of SET1/MLL complex subunits also antagonize HPL function in post-embryonic development. Genetic analysis is consistent with SET1/MLL complex subunits having both shared and unique functions in development. Furthermore, as observed in other species, we find that SET1/MLL complex homologues differentially affect global H3K4 methylation. Our results suggest that HP1 and a SET1/MLL-related complex may play antagonistic roles in the epigenetic regulation of specific developmental programs.

MRI assessment of ventricular function.

Cine-MRI is a robust non invasive technique able to assess regional and global systolic function of both ventricles. Conventinal cine-MRI was used for LV global function parameters both on horizontal long axis and vertical long axis, applying area-length methods, as in echocardiography. Recent developments of segmented k-space techniques allowed breath-held cine-MRI, making possible a rapid acquisition of the entire ventricles, both left and right. Using the Simpson's rule volumes are estimated with high accuracy, without any geometrical assumption; this method is considered gold standard for global function assessment. Regional function is studied by cine-MRI both qualitatively and quantitatively, as it represents the best technique in defining endo- and epi-cardial borders. The ability of quantify wall thickness and wall thickening makes cine-MRI highly suitable for stress-imaging, both in ischemia detection and viability assessment. Tagging is a novel technique, able to assess the complex mechanism of myocardial contraction and to quantify myocardial strain. Finally MRI is also able to assess diastolic function with phase velocity mapping.

The C. elegans Mi-2 chromatin-remodelling proteins function in vulval cell fate determination.

The Mi-2 protein is the central component of the recently isolated NuRD nucleosome remodelling and histone deacetylase complex. Although the NuRD complex has been the subject of extensive biochemical analyses, little is known about its biological function. Here we show that the two C. elegans Mi-2 homologues, LET-418 and CHD-3, play essential roles during development. The two proteins possess both shared and unique functions during vulval cell fate determination, including antagonism of the Ras signalling pathway required for vulval cell fate induction and the proper execution of the 2 degrees cell fate of vulval precursor cells, a process under the control of LIN-12 Notch signalling.

Endoscopic pancreatic stenting in pancreatic cancer.

Most pancreatic carcinomas are unresectable at the time of diagnosis; therefore, palliative treatment is very often the main concern of clinicians in this setting. The main symptoms resulting in the need for palliation in pancreatic cancer are obstructive jaundice, duodenal obstruction and pain. Therapeutic endoscopy plays a major role in the palliation of obstructive jaundice by stent placement into the biliary ducts. Initial experience has also been gained recently with endoscopic placement of expandable metallic stents to treat gastric outlet obstruction. Much less is known about the possible role of endoscopic pancreatic stenting in patients with unresectable pancreatic carcinoma. The main indication for pancreatic ductal stenting is 'obstructive' pain related to meals in patients with dilated main pancreatic duct beyond the stricture and intraluminal brachyradiotherapy. The technique of endoscopic pancreatic stenting does not substantially differ from that applied on the biliary tree. When technically possible, placement of 10 French plastic stents is preferred. According to the authors' indications, only about 15% of patients with advanced pancreatic cancer (55 of 355 in the present study) may potentially benefit from this technique. Pancreatic stenting may be obtained in more than 80% of these selected patients, with low morbidity (less than 10%) and no procedure-related mortality. According to the authors of the present and other studies reported in the literature, about 60% of patients treated because of 'obstructive' pain become symptom-free, and another 20% to 25% significantly reduce the amount of analgesic drugs required. Intraluminal brachyradiotherapy with 192iridium in the main pancreatic duct is a feasible and safe method to deliver high radiation doses to the tumour while sparing adjacent organs. Brachyradiotherapy may be performed alone or in conjunction with external beam radiotherapy. Because of the small number of patients suitable for this treatment, only a multicentre study will be able to detect whether intraluminal brachyradiotherapy in pancreatic cancer may have any positive impact on survival.

Functional characterization of the N terminus of Sir3p.

Silent information regulator 3 is an essential component of the Saccharomyces cerevisiae silencing complex that functions at telomeres and the silent mating-type loci, HMR and HML. We show that expression of the N- and C-terminal-encoding halves of SIR3 in trans partially complements the mating defect of the sir3 null allele, suggesting that the two domains have distinct functions. We present here a functional characterization of these domains. The N-terminal domain (Sir3N) increases both the frequency and extent of telomere-proximal silencing when expressed ectopically in SIR+ yeast strains, although we are unable to detect interaction between this domain and any known components of the silencing machinery. In contrast to its effect at telomeres, Sir3N overexpression derepresses transcription of reporter genes inserted in the ribosomal DNA (rDNA) array. Immunolocalization of Sir3N-GFP and Sir2p suggests that Sir3N directly antagonizes nucleolar Sir2p, releasing an rDNA-bound population of Sir2p so that it can enhance repression at telomeres. Overexpression of the C-terminal domain of either Sir3p or Sir4p has a dominant-negative effect on telomeric silencing. In strains overexpressing the C-terminal domain of Sir4p, elevated expression of either full-length Sir3p or Sir3N restores repression and the punctate pattern of Sir3p and Rap1p immunostaining. The similarity of Sir3N and Sir3p overexpression phenotypes suggests that Sir3N acts as an allosteric effector of Sir3p, either enhancing its interactions with other silencing components or liberating the full-length protein from nonfunctional complexes.

[Immediate reocclusion of the infrapopliteal segment after thrombolysis in acute ischemia of the lower limb of the thrombotic nature]. / La riocclusione immediata del segmento sottopopliteo dopo trombolisi nell'ischemia acuta dell'arto inferiore di natura trombotica.

Early reocclusion of below knee segment after fibrinolytic therapy is mainly due to thrombo-embolism, coagulopathy or to the arterial wall condition. 42 patients facing acute lower limb ischaemia because of iliofemoral thrombosis (prosthesis 19, native artery 23) underwent locoregional thrombolysis. UK was given in 33 cases while the others received rt-PA. The early reocclusion after fibrinolysis leads to a serious worsening in these patients; thrombosis in distal vessels and in microvasculature make any surgical approach unserviceable. Major amputation was required in 3 cases. We believe that fibrinolytic treatment has taken on great importance in making accurate diagnosing of thromboembolism and, once restored patency of distal vessels, allows to perform revascularization procedures.

The carboxy termini of Sir4 and Rap1 affect Sir3 localization: evidence for a multicomponent complex required for yeast telomeric silencing.

The Silent Information Regulatory proteins, Sir3 and Sir4, and the telomeric repeat-binding protein RAP1 are required for the chromatin-mediated gene repression observed at yeast telomeric regions. All three proteins are localized by immunofluorescence staining to foci near the nuclear periphery suggesting a relationship between subnuclear localization and silencing. We present several lines of immunological and biochemical evidence that Sir3, Sir4, and RAP1 interact in intact yeast cells. First, immunolocalization of Sir3 to foci at the yeast nuclear periphery is lost in rap1 mutants carrying deletions for either the terminal 28 or 165 amino acids of RAP1. Second, the perinuclear localization of both Sir3 and RAP1 is disrupted by overproduction of the COOH terminus of Sir4. Third, overproduction of the Sir4 COOH terminus alters the solubility properties of both Sir3 and full-length Sir4. Finally, we demonstrate that RAP1 and Sir4 coprecipitate in immune complexes using either anti-RAP1 or anti-Sir4 antibodies. We propose that the integrity of a tertiary complex between Sir4, Sir3, and RAP1 is involved in both the maintenance of telomeric repression and the clustering of telomeres in foci near the nuclear periphery.

Telomere maintenance and gene repression: a common end?

In yeast, the study of the teleomere has recently provided new information on the requirements for chromosome stability, on elements influencing nuclear architecture and on position-effect variegation.

SIR3 and SIR4 proteins are required for the positioning and integrity of yeast telomeres.

Heritable inactivation of genes occurs in specific chromosomal domains located at the silent mating type loci and at telomeres of S. cerevisiae. The SIR genes (for silent information regulators) are trans-acting factors required for this repression mechanism. We show here that the SIR3 and SIR4 gene products have a sub-nuclear localization similar to the telomere-associated RAP1 protein, which is found primarily in foci at the nuclear periphery of fixed yeast spheroplasts. In strains deficient for either SIR3 or SIR4, telomeres lose their perinuclear localization, as monitored by RAP1 immunofluorescence. The length of the telomeric repeat shortens in sir3 and sir4 mutant strains, and the mitotic stability of chromosome V is reduced. These data suggest that SIR3 and SIR4 are required for both the integrity and subnuclear localization of yeast telomeres, the loss of which correlates with loss of telomere-associated gene repression.

Analysis of mitotic and meiotic defects in Saccharomyces cerevisiae SRS2 DNA helicase mutants.

The hyper-gene conversion srs2-101 mutation of the SRS2 DNA helicase gene of Saccharomyces cerevisiae has been reported to suppress the UV sensitivity of rad18 mutants. New alleles of SRS2 were recovered using this suppressor phenotype. The alleles have been characterized with respect to suppression of rad18 UV sensitivity, hyperrecombination, reduction of meiotic viability, and definition of the mutational change within the SRS2 gene. Variability in the degree of rad18 suppression and hyperrecombination were found. The alleles that showed the severest effects were found to be missense mutations within the consensus domains of the DNA helicase family of proteins. The effect of mutations in domains I (ATP-binding) and V (proposed DNA binding) are reported. Some alleles of SRS2 reduce spore viability to 50% of wild-type levels. This phenotype is not bypassed by spo13 mutation. Although the srs2 homozygous diploids strains undergo normal commitment to meiotic recombination, this event is delayed by several hours in the mutant strains and the strains appear to stall in the progression from meiosis I to meiosis II.

[Composite bypass using endarterectomized autologous superficial femoral artery. A valid concept in the extension of lower limb salvage surgery]. / By-pass composito con arteria femorale superficiale autologa endoarterectomizzata. Un valido concetto nell'estensione della chirurgia di salvataggio dell'arto inferiore.

Saphenous vein is nowadays the material of choice performing on femoro-distal revascularisation; when this is not available, it is important to use a material which gives the closest approximation of an ideal conduit and for same time an easy handling during the execution of the anastomosis. Although vein's degenerative alterations are very rare, it has now been shown that there is widespread destruction of the endothelium among infrainguinal vein grafting, producing a relatively thrombogenic surface. These factors may contribute to the initial failure rate of these bypasses. For this reason we suggest to employ a segment of thromboendarterectomized SFA (superficial femoral artery) as a distal part of a composite bypass. Twenty-four composite bypasses were performed using three different methods over a total of 123 femoro-distal revascularizations. Eighteen months follow-up showed more than 50% and more than 75% patency rate comparing type B (graft or thromboendarterectomized SFA + autogenous saphenous vein) and type C (thromboendarterectomyied SFA + graft). We believe, waiting for a wider follow-up, that this technique could be a valid alternative to a femoro-distal revascularization when saphenous vein is not available.

The hyper-gene conversion hpr5-1 mutation of Saccharomyces cerevisiae is an allele of the SRS2/RADH gene.

The HPR5 gene has been defined by the mutation hpr5-1 that results in an increased rate of gene conversion. This mutation suppresses the UV sensitive phenotype of rad18 mutations in hpr5-1 rad18 double mutants by channeling the aborted repair events into a recombination repair pathway. The HPR5 gene has been cloned and is shown to be allelic to the SRS2/RADH gene, a putative DNA helicase. The HPR5 gene, which is nonessential, is tightly linked to the ARG3 locus chromosome X. The hpr5-1 allele contains missense mutation in the putative ATP binding domain. A comparison of the recombination properties of the hpr5-1 allele and the null allele suggests that recombination events in hpr5 defective strains can be generated by several mechanisms. We propose that the HPR5 gene functions in the RAD6 repair pathway.

Neuropsychological assessment of functional central nervous system disorders. I. Hemispheric functioning characteristics in schizophrenia and affective illness.

The neuropsychological characteristics of a group of schizophrenic and affective patients were assessed by mean of a comprehensive neuropsychological tool, the Luria-Nebraska Neuropsychological Batter (LNNB), to determine the lateralized hemispheric neurofunctional characteristics in major functional central nervous system disorders. The results showed that schizophrenics had more right-hemisphere impairment than affectives. They do not substantiate the hypothesis of right hemisphere-lateralized malfunctioning in functional mood disorders. Psychopharmacological treatment influences neuropsychological test performance, neuroleptics having the greatest effects. Pharmacological effects other than anticholinergic ones are responsible for the negative influence on neuropsychological test performance.