The Reverse Transcription Signature of N-\u3csub\u3e1\u3c/sub\u3e-Methyladenosine in RNA-Seq is Sequence Dependent

The combination of Reverse Transcription (RT) and high-throughput sequencing has emerged as a powerful combination to detect modified nucleotides in RNA via analysis of either abortive RT-products or of the incorporation of mismatched dNTPs into cDNA. Here we simultaneously analyze both parameters in detail with respect to the occurrence of N-1-methyladenosine (m1A) in the template RNA. This naturally occurring modification is associated with structural effects, but it is also known as a mediator of antibiotic resistance in ribosomal RNA. In structural probing experiments with dimethylsulfate, m1A is routinely detected by RT-arrest. A specifically developed RNA-Seq protocol was tailored to the simultaneous analysis of RT-arrest and misincorporation patterns. By application to a variety of native and synthetic RNA preparations, we found a characteristic signature of m1A, which, in addition to an arrest rate, features misincorporation as a significant component. Detailed analysis suggests that the signature depends on RNA structure and on the nature of the nucleotide 3’ of m1A in the template RNA, meaning it is sequence dependent. The RT-signature ofm1Awas used for inspection and confirmation of suspected modification sites and resulted in the identification of hitherto unknown m1A residues in trypanosomal tRNA

Complications in the surgical treatment of adolescent hallux valgus

Objective: Evaluation the degree of complications in the surgical treatment of adolescent hallux valgus Material and method: The study examines 47 cases of surgically treated children with adolescent hallux valgus with a mean age of 14.3 years. Most of the patients were female - 93.75%. and the most affected is the right foot - 51.21%. For diagnosis and follow-up of the treatment result, X-ray methods were used with angular imaging measurements - hallux valgus angle (HVA) and intrametatarsal angle (IMA). Results: The mean follow-up period was 15.8 m. The mean preoperative angle of hallux valgus was 30.19 o  and the mean preoperative intrametatarsal angle was 11.44o. In the final results we report a loss of correction of HVA on average to - 20.46 o (min 6.8 o max 38.2 o) and preservation of IM with an average value of 7.35 o. The Clavien Dindo classification was used to account of the postoperative complications. The recurrence rate reported at 10 months postoperatively were 15 cases or 31.91%. The following postoperative complications were reported for the follow-up period: avascular necrosis of the metatarsal head 1 year postoperatively and intraoperative fracture of the first metatarsal bone. Conclusions: Despite the many described surgical techniques, there are still no long-term indicative results for successfully used surgery. After processing our data and compare it with those of the world literature, we come to the conclusion that the rate of possible recurrence in the surgical treatment of AHV is high. The closure of the growth zone is confirmed as one of the criteria for the outcome of the treatment and the degree of postoperative recurrence of the deformity

Free-gliding screw fixation in slipped capital femoral epiphysis: potentially growing implants for symptomatic and prophylactic pinning

Introduction: In situ fixation is the gold standard for mild and moderate slipped capital femoral epiphysis (SCFE) cases. The condition is associated with a low percentage of avascular necrosis and chondrolysis.[1] The present study examines the postoperative femoral neck remodelling and implant elongation in cases of therapeutic and prophylactic in situ fixation using the free-gliding screw system. Aim: The aim of our study was to assess the postoperative femoral neck growth and evaluate the biomechanical evolution and complication’s rate for 19 therapeutic and 11 prophylactic in situ fixations with a free-gliding screw. Materials and methods: We measured the preoperative and postoperative articulo-trochanteric distance (ATD), alpha angle (α angle) and screw elongation in symptomatic hips and in contralateral hips with prophylactic fixation. We compared the radiographic parameters of 30 hips. Results: ATD remains approximately the same for symptomatic cases, whereas it increases for prophylactic fixated hip. Screw elongates in both group with statistically higher value for the prophylactic group. The alpha angle remains pathological in these cases with a mean value of 67.12±4.62°, but decreases for group II. Screw elongates by a mean value of 3.14±2.74 mm for group I and 6.78±8.81 mm for group II. Conclusions: Prophylactic in situ fixation with free-gliding screws does not affect the proximal femoral growth (ATD), and does not decrease the alpha angle significantly. Screw elongates statistically in both groups, but more significantly for group II. For symptomatic hips, the in situ fixation allows the femoral neck to grow with ATD preserved, but significantly less than in group II. The alpha angle decreases but remains pathological

Massive “risotto bursitis” of the great trochanter bursa after proximal femoral varus osteotomy with 5,0 LCP- a case report

The “risotto phenomenon” is a rare pathologic finding, mostly seen as a nonspecific response to chronic inflammation around the shoulder joint- subacromial and subdeltoid bursitis, rheumatoid arthritis, sero-negative inflammatory arthritis, septic arthritis and tuberculous arthritis. A few scientific reports associate rice body formation with the use of different type of osteosynthesis, bony anchors and bioabsorbable sutures. They are usually an incidental asymptomatic finding, requiring no specific treatment, but could be symptomatic demanding surgical excision. We present the clinical case of a 17-year- old female patient with a “risotto bursitis” of the great trochanter bursa, documented during planned surgical removal of a locking compression plate after proximal femoral varus osteotomy for bilateral developmental dysplasia of the hip treatment

Diastereoselectivity of 5‑Methyluridine Osmylation Is Inverted inside an RNA Chain

In this study, we investigated the reaction of the osmium tetroxide–bipyridine complex with pyrimidines in RNA. This reagent, which reacts with the diastereotopic 5–6 double bond, thus leading to the formation of two diastereomers, was used in the past to label thymidine and 5-methylcytosine in DNA. In light of the growing interest in post-transcriptional RNA modifications, we addressed the question of whether this reagent could be used for labeling of the naturally occurring RNA modifications 5-methylcytosine and 5-methyluridine. On nucleoside level, 5-methylcytosine and 5-methyluridine revealed a 5- and 12-fold preference, respectively, over their nonmethylated equivalents. Performing the reaction on an RNA level, we could show that the steric environment of a pentanucleotide has a major detrimental impact on the reaction rate of osmylation. Interestingly, this drop in reactivity was due to a dramatic change in diastereoselectivity, which in turn resulted from impediment of the preferred attack via the <i>si</i> side. Thus, while on the nucleoside level, the absolute configuration of the major product of osmylation of 5-methyluridine was (5<i>R</i>,6<i>S</i>)-5-methyluridine glycol-dioxoosmium-bipyridine, reaction with an RNA pentanucleotide afforded the corresponding (5<i>S</i>,6<i>R</i>)-diastereomer as the major product. The change in diastereoselectivity lead to an almost complete loss of selectivity toward 5-methylcytosine in a pentanucleotide context, while 5-methyluridine remained about 8 times more reactive than the canonical pyrimidines. On the basis of these findings, we evaluate the usefulness of osmium tetroxide–bipyridine as a potential label for the 5-methyluridine modification in transcriptome-wide studies

Total Knee Arthroplasty in the Valgus Knee – A Surgical Challenge (Part 1)

The valgus knee presents a unique set of problems that must be addressed during total knee arthroplasty.  Both bone and soft-tissue deformities complicate restoration of proper alignment, positioning of components, and attainment of joint stability.  The variables that may need to be addressed include lateral femoral condyle or tibial plateau deficiencies secondary to developmental abnormalities, and/or wear; primary or acquired contracture of the lateral capsular and ligamentous structures; and, occasionally, laxity of the medial collateral ligament.  Understanding the specific pathologic anatomy associated with the valgus knee is a prerequisite to selecting the proper surgical method to optimize component position and restore soft-tissue balance. The aim of this article is to review the anatomical variations underlying a valgus knee, to assess the best pre-operative planning and to evaluate how to choose the grade of constraint of the implant. We will also review the main approaches and surgical techniques both for bone cuts and soft tissue managemen

The reverse transcription signature of N-1-methyladenosine in RNA-Seq is sequence dependent

The combination of Reverse Transcription (RT) and high-throughput sequencing has emerged as a powerful combination to detect modified nucleotides in RNA via analysis of either abortive RT-products or of the incorporation of mismatched dNTPs into cDNA. Here we simultaneously analyze both parameters in detail with respect to the occurrence of N-1-methyladenosine (m1A) in the template RNA. This naturally occurring modification is associated with structural effects, but it is also known as a mediator of antibiotic resistance in ribosomal RNA. In structural probing experiments with dimethylsulfate, m1A is routinely detected by RT-arrest. A specifically developed RNA-Seq protocol was tailored to the simultaneous analysis of RT-arrest and misincorporation patterns. By application to a variety of native and synthetic RNA preparations, we found a characteristic signature of m1A, which, in addition to an arrest rate, features misincorporation as a significant component. Detailed analysis suggests that the signature depends on RNA structure and on the nature of the nucleotide 3′ of m1A in the template RNA, meaning it is sequence dependent. The RT-signature of m1A was used for inspection and confirmation of suspected modification sites and resulted in the identification of hitherto unknown m1A residues in trypanosomal tRNA.SCOPUS: ar.jinfo:eu-repo/semantics/publishe