Degenerative cervical myelopathy caused by posttraumatic severe atlantoaxial dislocation over 10 years in patients with right vertebral artery hypoplasia: A case report of successful management.

Introduction: Degenerative cervical myelopathy caused by long-standing neglected AAD is rare, especially in severe cases. Combined with the exceptional right vertebral artery hypoplasia condition, treatment must be integrated into multitherapy to avoid fatal complications.

Case: A 55-year-old man presented with degenerative cervical myelopathy caused by posttraumatic severe atlantoaxial dislocation for more than 10 years in patients with right vertebral artery hypoplasia.

Transarticular Screw Fixation in the Treatment of Severe C1-C2 Dislocation: A Case Series Report.

Background: To aim of the present paper was to evaluate the results of halo traction and transarticular screw fixation combined with bone autoplasty in patients with severe atlantoaxial dislocation.

Case Presentation: This is a retrospective study of severe cases of atlantoaxial dislocation in nine patients (six men and three women) treated with preoperative halo traction and posterior C1-C2 transarticular screw fixation combined with bone autoplasty from June 2006 to June 2011 at the Saint Paul Hospital (Hanoi). The mean age of patients was 37.

Triad of meningothelial meningioma, rhabdoid meningioma and ependymoma: successful management of an extremely rare case.

An 8-year-old girl was admitted with four limb weakness for 2 months. Hyperactive reflexes were observed in all four limbs, and positive Hoffmann's signs were revealed. An MRI spine with the coronal slide detected two tumors, first in the intradural and intramedullary space at the C2-C4 level and the second in the intradural and extramedullary space at the C5-C7 level.

Design and implementation of finite time sliding mode controller for fuzzy overhead crane system.

This paper considers the problem of fuzzy overhead crane system modelling and finite-time stability/boundedness via sliding mode control (SMC) method. Due to the strong coupling of control input, the fuzzy technique is utilized to linearize the overhead crane system and a fuzzy overhead crane model is established with appropriate membership functions. Considering the bad effect, including the swing of hook and plates, the external disturbances of the friction and air resistances, is inevitable during the transportation of copper electrode plates, the SMC method is adopted to stabilize the fuzzy system and robust to these interference signals.

Does sperm DNA fragmentation correlate with semen parameters?

Purpose: This study aimed to investigate the association between sperm quality assessed by routine semen analysis and sperm DNA integrity assay.

Methods: In our cross-sectional study, a total of 318 men from the infertile couples were enrolled from December 2017 to March 2019 at the Hue Center for Reproductive Endocrinology and Infertility, Vietnam. General characteristics and semen parameters were detected.

Cryopreservation of human spermatozoa by vitrification versus conventional rapid freezing: Effects on motility, viability, morphology and cellular defects.

Objectives: Sperm cryopreservation has great potential for male infertility treatment as used in assisted reproduction technology (ART). There are a variety of cryopreservation methods in order to preserve sperm in a long term. Although conventional freezing and vitrification now are used widely, they have damage on sperm parameters as well as sperm DNA integrity.

Thinning and drilling laser-assisted hatching in thawed embryo transfer: A randomized controlled trial.

Objective: In frozen and thawed embryos, the zona pellucida (ZP) can be damaged due to hardening. Laser-assisted hatching (LAH) of embryos can increase the pregnancy rate. This study compared thinning and drilling of the ZP before frozen embryo transfer (FET).

A Cyclin T1 point mutation that abolishes positive transcription elongation factor (P-TEFb) binding to Hexim1 and HIV tat.

Background: The positive transcription elongation factor b (P-TEFb) plays an essential role in activating HIV genome transcription. It is recruited to the HIV LTR promoter through an interaction between the Tat viral protein and its Cyclin T1 subunit. P-TEFb activity is inhibited by direct binding of its subunit Cyclin T (1 or 2) with Hexim (1 or 2), a cellular protein, bound to the 7SK small nuclear RNA.

Characterization of MRP RNA-protein interactions within the perinucleolar compartment.

The perinucleolar compartment (PNC) forms in cancer cells and is highly enriched with a subset of polymerase III RNAs and RNA-binding proteins. Here we report that PNC components mitochondrial RNA-processing (MRP) RNA, pyrimidine tract-binding protein (PTB), and CUG-binding protein (CUGBP) interact in vivo, as demonstrated by coimmunoprecipitation and RNA pull-down experiments. Glycerol gradient analyses show that this complex is large and sediments at a different fraction from known MRP RNA-containing complexes, the MRP ribonucleoprotein ribozyme and human telomerase reverse transcriptase.

Splicing-independent recruitment of U1 snRNP to a transcription unit in living cells.

Numerous non-coding RNAs are known to be involved in the regulation of gene expression. In this work, we analyzed RNAs that co-immunoprecipitated with human RNA polymerase II from mitotic cell extracts and identified U1 small nuclear RNA (snRNA) as a major species. To investigate a possible splicing-independent recruitment of U1 snRNA to transcription units, we established cell lines having integrated a reporter gene containing a functional intron or a splicing-deficient construction.

Evolution of 7SK RNA and its protein partners in metazoa.

7SK RNA is a key player in the regulation of polymerase II transcription. 7SK RNA was considered as a highly conserved vertebrate innovation. The discovery of poorly conserved homologs in several insects and lophotrochozoans, however, implies a much earlier evolutionary origin.

The transcription-dependent dissociation of P-TEFb-HEXIM1-7SK RNA relies upon formation of hnRNP-7SK RNA complexes.

The positive transcription elongation factor P-TEFb controls the elongation of transcription by RNA polymerase II. P-TEFb is inactivated upon binding to HEXIM1 or HEXIM2 proteins associated with a noncoding RNA, 7SK. In response to the inhibition of transcription, 7SK RNA, as well as HEXIM proteins, is released by an unknown mechanism and P-TEFb is activated.

Inhibition of HIV-1 replication by P-TEFb inhibitors DRB, seliciclib and flavopiridol correlates with release of free P-TEFb from the large, inactive form of the complex.

Background: The positive transcription elongation factor, P-TEFb, comprised of cyclin dependent kinase 9 (Cdk9) and cyclin T1, T2 or K regulates the productive elongation phase of RNA polymerase II (Pol II) dependent transcription of cellular and integrated viral genes. P-TEFb containing cyclin T1 is recruited to the HIV long terminal repeat (LTR) by binding to HIV Tat which in turn binds to the nascent HIV transcript. Within the cell, P-TEFb exists as a kinase-active, free form and a larger, kinase-inactive form that is believed to serve as a reservoir for the smaller form.

Transcription-dependent association of multiple positive transcription elongation factor units to a HEXIM multimer.

The positive transcription elongation factor (P-TEFb) comprises a kinase, CDK9, and a Cyclin T1 or T2. Its activity is inhibited by association with the HEXIM1 or HEXIM2 protein bound to 7SK small nuclear RNA. HEXIM1 and HEXIM2 were found to form stable homo- and hetero-oligomers.

Binding of the 7SK snRNA turns the HEXIM1 protein into a P-TEFb (CDK9/cyclin T) inhibitor.

The positive transcription elongation factor b (P-TEFb) plays a pivotal role in productive elongation of nascent RNA molecules by RNA polymerase II. Core active P-TEFb is composed of CDK9 and cyclin T. In addition, mammalian cell extracts contain an inactive P-TEFb complex composed of four components, CDK9, cyclin T, the 7SK snRNA and the MAQ1/HEXIM1 protein.

MAQ1 and 7SK RNA interact with CDK9/cyclin T complexes in a transcription-dependent manner.

Positive transcription elongation factor b (P-TEFb) comprises a cyclin (T1 or T2) and a kinase, cyclin-dependent kinase 9 (CDK9), which phosphorylates the carboxyl-terminal domain of RNA polymerase II. P-TEFb is essential for transcriptional elongation in human cells. A highly specific interaction among cyclin T1, the viral protein Tat, and the transactivation response (TAR) element RNA determines the productive transcription of the human immunodeficiency virus genome.