Electrical nerve stimulation therapy in refractory primary monosymtomatic enuresis - A sistematic review.

OBJECTIVE: To analyze the effect of electrical nerve stimulation on urinary symptoms in pediatric patients with monosymptomatic primary enuresis refractory to conventional treatment. METHODS: Three databases (Medline, Embase, and Cochrane) were searched and 160 studies were identified by July 15, 2020. After establishing and applying the inclusion and exclusion criteria, a step-by-step analysis was performed using the title, abstract and full text. The Cochrane Collaboration Tool was then used to analyze the biases of the selected studies. RESULTS: Of the 160 articles found, 03 were selected for this systematic review. In 02 studies there was a significant reduction in the number of wet nights/week after electrical nerve stimulation. Urodynamic pattern was evaluated in 01 study, with improvement of maximum cystometric capacity in the intervention group. About maximum voided volume, there was no improvement in 01 study, but in other, there was increase in the intervention group. CONCLUSION: Electrical nerve stimulation might promote improvement in partial and total response scores over the number of dry nights, with no improvement in urodynamic parameters, and could be considered as an feasible option in the management of refractory monosymptomatic primary enuresis. However, it is worth emphasizing the need to conduct more RCTs with a larger sample for better evaluation of the role of neurostimulation.

Changes in the expression of the Alzheimer's disease-associated presenilin gene in drosophila heart leads to cardiac dysfunction.

Mutations in the presenilin genes cause the majority of early-onset familial Alzheimer's disease. Recently, presenilin mutations have been identified in patients with dilated cardiomyopathy (DCM), a common cause of heart failure and the most prevalent diagnosis in cardiac transplantation patients. However, the molecular mechanisms, by which presenilin mutations lead to either AD or DCM, are not yet understood. We have employed transgenic Drosophila models and optical coherence tomography imaging technology to analyze cardiac function in live adult Drosophila. Silencing of Drosophila ortholog of presenilins (dPsn) led to significantly reduced heart rate and remarkably age-dependent increase in end-diastolic vertical dimensions. In contrast, overexpression of dPsn increased heart rate. Either overexpression or silencing of dPsn resulted in irregular heartbeat rhythms accompanied by cardiomyofibril defects and mitochondrial impairment. The calcium channel receptor activities in cardiac cells were quantitatively determined via real-time RT-PCR. Silencing of dPsn elevated dIP3R expression, and reduced dSERCA expression; overexprerssion of dPsn led to reduced dRyR expression. Moreover, overexpression of dPsn in wing disc resulted in loss of wing phenotype and reduced expression of wingless. Our data provide novel evidence that changes in presenilin level leads to cardiac dysfunction, owing to aberrant calcium channel receptor activities and disrupted Wnt signaling transduction, indicating a pathogenic role for presenilin mutations in DCM pathogenesis.

Tocilizumab: is there life beyond anti-TNF blockade?

Anti-TNF-α therapy has become the most effective biological treatment for rheumatoid arthritis. Despite having changed the prognosis of the disease establishing new targets for treatment strategy, there are several aspects that still remain unmatched. About 30% of the patients with rheumatoid arthritis have a less than satisfactory response to anti-TNF therapy, which has led the way for the pursuit of new targets and approaches to treatment. IL-6 is one of these alternative targets and data from the more recent clinical trials involving tocilizumab (an anti-IL-6 soluble receptor antibody) suggest advantages in relation to some clinical aspects which are not addressed by anti-TNF-α treatment.

A story: unpaired adenosine bases in ribosomal RNAs.

In 1985 an analysis of the Escherichia coli 16 S rRNA covariation-based structure model revealed a strong bias for unpaired adenosines. The same analysis revealed that the majority of the G, C, and U bases were paired. These biases are (now) consistent with the high percentage of unpaired adenosine nucleotides in several structure motifs. An analysis of a larger set of bacterial comparative 16 S and 23 S rRNA structure models has substantiated this initial finding and revealed new biases in the distribution of adenosine nucleotides in loop regions. The majority of the adenosine nucleotides are unpaired, while the majority of the G, C, and U bases are paired in the covariation-based structure model. The unpaired adenosine nucleotides predominate in the middle and at the 3' end of loops, and are the second most frequent nucleotide type at the 5' end of loops (G is the most common nucleotide). There are additional biases for unpaired adenosine nucleotides at the 3' end of loops and adjacent to a G at the 5' end of the helix. The most prevalent consecutive nucleotides are GG, GA, AG, and AA. A total of 70 % of the GG sequences are within helices, while more than 70 % of the AA sequences are unpaired. Nearly 50 % of the GA sequences are unpaired, and approximately one-third of the AG sequences are within helices while another third are at the 3' loop.5' helix junction. Unpaired positions with an adenosine nucleotide in more than 50 % of the sequences at the 3' end of 16 S and 23 S rRNA loops were identified and arranged into the A-motif categories XAZ, AAZ, XAG, AAG, and AAG:U, where G or Z is paired, G:U is a base-pair, and X is not an A and Z is not a G in more than 50 % of the sequences. These sequence motifs were associated with several structural motifs, such as adenosine platforms, E and E-like loops, A:A and A:G pairings at the end of helices, G:A tandem base-pairs, GNRA tetraloop hairpins, and U-turns.

A test of the model to predict unusually stable RNA hairpin loop stability.

To investigate the accuracy of a model [Giese et al., 1998, Biochemistry37:1094-1100 and Mathews et al., 1999, JMol Biol 288:911-940] that predicts the stability of RNA hairpin loops, optical melting studies were conducted on sets of hairpins previously determined to have unusually stable thermodynamic parameters. Included were the tetraloops GNRA and UNCG (where N is any nucleotide and R is a purine), hexaloops with UU first mismatches, and the hairpin loop of the iron responsive element, CAGUGC. The experimental values for the GNRA loops are in excellent agreement (deltaG degrees 37 within 0.2 kcal/mol and melting temperature (TM) within 4 degrees C) with the values predicted by the model. When the UNCG hairpin loops are treated as tetraloops, and a bonus of 0.8 kcal/mol included in the prediction to account for the extra stable first mismatch (UG), the measured and predicted values are also in good agreement (deltaG degrees 37 within 0.7 kcal/mol and TM within 3 degrees C). Six hairpins with unusually stable UU first mismatches also gave good agreement with the predictions (deltaG degrees 37 within 0.5 kcal/mol and TM within 8 degrees C), except for hairpins closed by wobble base pairs. For these hairpins, exclusion of the additional stabilization term for UU first mismatches improved the prediction (AG degrees 37 within 0.1 kcal/mol and TM within 3 degrees C). Hairpins with the iron-responsive element loop were not predicted well by the model, as measured deltaG degrees 37 values were at least 1 kcal/mol greater than predicted.

Stability of RNA hairpins closed by wobble base pairs.

Thermodynamic parameters are reported for hairpin formation in 1 M NaCl by RNA sequences of the type GGXANmAYCC, where XY is the wobble base pair, GU or UG, and the underlined loop sequences are three to eight nucleotides. A nearest-neighbor analysis indicates the free energy of loop formation is dependent upon loop size and closing base pair. Hairpin loops closed by UG base pairs are on average 1.3 kcal/mol less stable than hairpins closed by GU base pairs. The hairpin loops closed by UG have approximately the same stability as hairpin loops closed by AU/UA base pairs, while the loops closed by GU are approximately 0.7 kcal/mol more stable than hairpins loops closed by GC/CG base pairs. These results, combined with the model previously developed [Serra et al. (1997) Biochemistry 36, 4844] to predict the stability for hairpin loops closed by Watson-Crick base pairs, allow for the following model to predict the stability of hairpin loops: delta G degree 37L(n) = delta G degree 37iL(n) + delta G degree 37mm + 0.6 (if closed by AU, UA, or UB) - 0.7 (if closed by GU) - 0.7 (if first mismatch is GA or UU except for loops closed by GU). Here, delta G degree 37iL(n) is the free energy increment for initiating a loop of n nucleotides with a CG or GC pair, and delta G degree 37mm is the free energy for the interaction of the first mismatch with the closing base pair. For hairpin loops of n = 4-9, delta G037iL(n) is 4.9, 5.0, 5.0, 5.0, 4.9, and 5.5 kcal/mol, respectively. For hairpin loops of n = 3, delta G degree 37L(3) = +4.8 + 0.6 (if closed by AU, UA, or UG) kcal/mol. Thermodynamic parameters for hairpin formation in 1 M NaCl for 13 naturally occurring RNA hairpin sequences closed by wobble base pairs are reported. The model provides good agreement for both TM and delta G degree 37 for most hairpins studied. Thermodynamic values for five terminal mismatches adjacent to wobble base pairs are also reported.

Improved parameters for the prediction of RNA hairpin stability.

Thermodynamic parameters are reported for hairpin formation in 1 M NaCl by RNA sequences of the type GGXANmAYCC, where XY is the set of four Watson-Crick base pairs and the underlined loop sequences are three to nine nucleotides. A nearest neighbor analysis of the data indicates the free energy of loop formation at 37 degrees C is dependent upon loop size and closing base pair. The model previously developed to predict the stability for RNA hairpin loops (n > 3) includes contributions from the size of the loop, the identity of the closing base pair, the free energy increment (deltaGo(37mm)) for the interaction of the closing base pair with the first mismatch and an additional stabilization term for GA and UU first mismatches [Serra, M. J., Axenson, T. J., & Turner, D. H. (1994) Biochemistry 33, 14289]. The results presented here allow improvements in the parameters used to predict RNA hairpin stability. For hairpin loops of n = 4-9, deltaGo(37iL)(n) is 4.9, 5.0, 5.0, 5.0, 4.9, and 5.5 kcal/mol, respectively, and the penalty for hairpin closure by AU or UA is +0.6 kcal/mol. deltaGo(37iL)(n) is the free energy for initiating a loop of n nucleotides. The model for predicting hairpin loop stability for loops larger than three becomes deltaGo(37L)(n) = deltaGo(37iL)(n) + deltaGo(37mm) + 0.6(if closed by AU or UA) - 0.7(if first mismatch is GA or UU). Hairpin loops of three are modeled as independent of loop sequence with deltaGo(37iL)(3) = 4.8 and the penalty for AU closure of +0.6 kcal/mol. Thermodynamic parameters for hairpin formation in 1 M NaCl for 11 naturally occurring RNA hairpin sequences are reported. The model provides good agreement with the measured values for both T(M) (within 10 degrees C of the measured value) and deltaGo(37) (within 0.8 kcal/mol of the measured value) for hairpin formation. In general, the nearest neighbor model allows prediction of RNA hairpin stability to within 5-10% of the experimentally measured values.

Structural features of a six-nucleotide RNA hairpin loop found in ribosomal RNA.

The hairpin loop GUAAUA occurs frequently in ribosomal RNA. Optical melting studies show that r(GGCGUAAUAGCC) folds into a hairpin containing this loop. The structural features of the r(GGCGUAAUAGCC) hairpin have been determined by NMR and molecular modeling. NOEs from G4-H1' to A9-H2 and from A9-H2 to G10-H1' show that G4 and A9 form a sheared base pair with two hydrogen bonds: A-N7 to G-NH2 and A-NH6 to G-N3. One-dimensional NOE data show no NOEs between the imino protons of U5 and U8, but NOEs are observed between the U5-H1' and the U8-H6 and U8-H5, thus orienting the U8 imino proton away from U5. Thus U5 and U8 do not form an imino hydrogen-bonded U.U pair. The U5-H2' exhibits NOEs to both the A6-H8 and A7-H8, and the 3' phosphorus resonances of U5 and A6 are shifted downfield. This suggests that the helix turn is between the U5 and A6 nucleotides. The JH1'-H2 and JH3'-H4' coupling constants indicate that the loop is dynamic, particularly at 35 degrees C, well below the melting temperature of 63 degrees C. Structures were generated using 75 distance and 46 dihedral angle restraints. In these structures, the U5 base is stacked on the sheared base pair formed by G4 and A9 and can initiate a uridine turn similar to that observed in the anticodon loop of tRNA. The A6, A7, and U8 bases can stack on one another with their hydrogen-bonding surfaces exposed to the solvent, suggesting that they are available for tertiary interactions or protein recognition in rRNA. A range of loop structures are consistent with the data, however. The lack of formation of a U.U mismatch is consistent with a recent model that predicts the stability of hairpin loops of six nucleotides on the basis of the closing base pair and first mismatch in the loop [Serra, M. J., Axenson, T. J., & Turner, D. H. (1994) Biochemistry 33, 14289-14296].

A model for the stabilities of RNA hairpins based on a study of the sequence dependence of stability for hairpins of six nucleotides.

Thermodynamic parameters are reported for hairpin formation in 1 M NaCl by RNA sequences of the type GGCXUAAUYGCC, where XY is the set of 10 possible mismatch base pairs. A nearest neighbor analysis of the data indicates the free energy for loop formation at 37 C varies from 2.9 to 4.5 kcal/mol. Thermodynamic parameters are also reported for hairpin formation by RNA sequences of the type GGXGUAAUAYCC (where XY are CG, GC, AU, UA, GU, and UG), with the common naturally occurring GA first mismatch (45% of small and large subunit rRNA loops of six). These results allow the development of a model to predict the stability of RNA hairpin loops. The model includes the size of the loop, the identity of the closing base pair, the free energy increment (delta G zero 37MM) for interaction of the closing base pair with the first mismatch, and an additional stabilization term for GA and UU first mismatches. delta G zero 37L(n) = delta G zero 37i(n) + delta G zero 37MM + 0.4 (if closed by AU or UA) -0.7 (if first mismatch is GA or UU). Here delta G zero 37i(n) is the free energy for initiating a loop of n nucleotides. delta G zero 37i(n) for n = 4-9 is 4.9, 4.4, 5.0, 5.0, 5.1, and 5.2 kcal/mol, respectively. The delta G zero 37MM is derived from measurements of model duplexes with terminal mismatches. The model gives good agreement when tested against four naturally occurring hairpin sequences.

Sequence of the gene coding for ribosomal protein S8 of Xenopus laevis.

We present here the cloning and the entire sequence of one of the two gene copies coding for ribosomal protein (r-protein) S8 in Xenopus laevis (corresponding to r-protein S7 in rat) and its flanking regions. The S8a gene contains seven exons and six introns for a total length of about 12,700 bp coding for a mRNA of 663 nucleotides (nt) plus a poly(A) tail. Mapping of the 5' end of the gene has shown that the transcription start point is located in a pyrimidine-rich tract, as has been observed for all r-protein-encoding genes of X. laevis and other vertebrates so far characterized. A computer analysis of the S8a sequence has revealed the presence of a 220-nt sequence repeated, with some variations, once in each of the six introns. RNA analysis by hybridization with oligo probes specific for the two gene copies coding for r-protein S8 has demonstrated that the two of them are expressed at similar levels both in oocytes and in embryos.

RNA hairpin loop stability depends on closing base pair.

Thermodynamic parameters are reported for hairpin formation in 1 M NaCl by RNA sequences of the type GGXAUAAUAYCC, where X and Y are CG, GC, AU, UA, GU, or UG. A nearest neighbor analysis of the data indicates the free energy change for loop formation at 37 degrees C, delta degrees Gl,37, averages 3.4 kcal/mol for hairpin loops closed with C.G, G.C, and G.U pairs. In contrast, delta G degree l,37 averages 4.6 kcal/mol for loops closed with A.U, U.A, or U.G pairs. Thus the stability of an RNA hairpin depends on the closing base pair. The hairpin with a GA mismatch that is formed by GGCGUAAUAGCC is more stable than the corresponding hairpin with an AA mismatch. Thus hairpin stability also depends on loop sequence. These effects are not included in current algorithms for prediction of RNA structure from sequence.

Changes in RNA polymerase activity in isolated mouse uterine nuclei during the decidual cell reaction.

The artificially stimulated decidual cell reaction has been used as a model to study changes occurring in the uterus at the time of implantation. Activities of RNA polymerases I, II and III were measured in uterine nuclei isolated from ovariectomized non-primed mice, hormonally primed mice, and hormonally primed mice following stimulation of the decidual cell reaction. Activities of all three RNA polymerases increased following hormonal priming of ovariectomized mice. In nuclei from stimulated uterine horns, activities of RNA polymerases I and III increased 9 h after stimulation of the decidual cell reaction and remained elevated through 21 h. RNA polymerase II activity did not change following stimulation of the decidual cell reaction. These changes in RNA polymerase activities occur at the time of increased histone modifications and may result from changes in the template capacity.