Are the Spinal Changes in the Course of Scoliogeny Primary but Secondary?

In this opinion article, there is an analysis and discussion regarding the effects of growth on the spinal and rib cage deformities, the role of the rib cage in scoliogeny, the lateral spinal profile in adolescent idiopathic scoliosis (AIS), the genetics and epigenetics of AIS, and the interesting and novel field investigating the sleep impact at nighttime on AIS in relation to the sequence of the scoliogenetic changes in scoliotics. The expressed opinions are mainly based on the published peer-reviewed research of the author and his team of co-authors. Based on the analysis noted above, it can be postulated that the vertebral growth changes in the spine during initial idiopathic scoliosis (IS) development are not primary-intrinsic but secondary changes. The primary cause starting the deformity is not located within the vertebral bodies. Instead, the deformations seen in the vertebral bodies are the secondary effects of asymmetrical loads exerted upon them, due to muscular loads, growth, and gravity.

Why Is There Always a Remnant Rib Hump Deformity after Spinal Operations in Idiopathic Scoliosis: Aetiological Implications and Recognition of the Proper Rib Level for Costoplasty.

The aim of this report is to review the literature dealing with the postoperative correction of rib hump (RH) after spinal operations for adolescent idiopathic scoliosis (AIS) and its aetiological implications of hump postoperative fate for IS. Recommendations related to RH deformity for the follow-up of younger asymmetric but not scoliotic children are provided, and the concept that clinical monitoring of the chest deformity is more important than merely an initially negative radiographic examination (curve less than 10°) is underlined. Additionally, guidelines are provided based on the segments T1-T12 rib index (RI) in the existing lateral preoperative radiographs for the optimal selection of the rib level for a successfully costoplasty. This review is based on the collected articles that used either the RI method, derived from the double rib contour sign (DRCS) at the lateral spinal radiographs, or alternative methods for the assessment of the RH deformity and presented the results of the operative treatment of the scoliotic spine on RH. A total of 19 relevant articles published from 1976 to 2022 were found in PubMed. Findings: All the above articles show that not only is the hump incompletely corrected, but it recurs and worsens during the follow-up and even more intensively in skeletally immature operated scoliosis children. Conclusions and Future Directions: Surgery straightens the spine, yet the RH is corrected approximately only as much as the spinal derotation. The only way to correct the RH more is with costoplasty, which, however, is not performed in most cases for many reasons. The key reason for this phenomenon is the fact that the RH deformity (RHD) is mainly due to the asymmetric development of the ribs and much less so due to the rotation of the vertebrae in the thoracic spine. Surgery on the spine cannot limit the asymmetry of the ribs or stop the mechanism that causes their asymmetrical growth. The results presented in all the reviewed articles support the important protagonistic role of RHD on scoliogenesis, which precedes the subsequent formed spinal deformity.

Fusarium verticillioides NAT1 (FDB2) N-malonyltransferase is structurally, functionally and phylogenetically distinct from its N-acetyltransferase (NAT) homologues.

Fusarium endophytes damage cereal crops and contaminate produce with mycotoxins. Those fungi overcome the main chemical defence of host via detoxification by a malonyl-CoA-dependent enzyme homologous to xenobiotic metabolizing arylamine N-acetyltransferase (NAT). In Fusarium verticillioides (teleomorph Gibberella moniliformis, GIBMO), this N-malonyltransferase activity is attributed to (GIBMO)NAT1, and the fungus has two additional isoenzymes, (GIBMO)NAT3 (N-acetyltransferase) and (GIBMO)NAT2 (unknown function). We present the crystallographic structure of (GIBMO)NAT1, also modelling other fungal NAT homologues. Monomeric (GIBMO)NAT1 is distinctive, with access to the catalytic core through two "tunnel-like" entries separated by a "bridge-like" helix. In the quaternary arrangement, (GIBMO)NAT1 monomers interact in pairs along an extensive interface whereby one entry of each monomer is covered by the N-terminus of the other monomer. Although monomeric (GIBMO)NAT1 apparently accommodates acetyl-CoA better than malonyl-CoA, dimerization changes the active site to allow malonyl-CoA to reach the catalytic triad (Cys110, His158 and Asp173) via the single uncovered entry, and anchor its terminal carboxyl-group via hydrogen bonds to Arg109, Asn157 and Thr261. Lacking a terminal carboxyl-group, acetyl-CoA cannot form such stabilizing interactions, while longer acyl-CoAs enter the active site but cannot reach catalytic Cys. Other NAT isoenzymes lack such structural features, with (GIBMO)NAT3 resembling bacterial NATs and (GIBMO)NAT2 adopting a structure intermediate between (GIBMO)NAT1 and (GIBMO)NAT3. Biochemical assays confirmed differential donor substrate preference of (GIBMO)NAT isoenzymes, with phylogenetic analysis demonstrating evolutionary separation. Given the role of (GIBMO)NAT1 in enhancing Fusarium pathogenicity, unravelling the structure and function of this enzyme may benefit research into more targeted strategies for pathogen control.

The rib index is not practically affected by the distance between the radiation source and the examined child.

BACKGROUND: All lateral spinal radiographs in idiopathic scoliosis (IS) show a Double Rib Contour Sign (DRCS) of the thoracic cage, a radiographic expression of the rib hump. The outline of the convex overlies the contour of the concave ribs. The rib index (RI) method was extracted from the DRCS to evaluate rib hump deformity in IS patients. The RI was calculated by the ratio of spine distances d1/d2 where d1 is the distance between the most extended point of the most extending rib contour and the posterior margin of the corresponding vertebra on the lateral scoliosis films, while d2 is the distance from the least projection rib contour and the posterior margin of the same vertebra, (Grivas et al 2002). In a symmetric thorax the "rib index" is 1. This report is the validity study of DRCS, ie how the rib index is affected by the distance between the radiation source and the irradiated child. METHODS: The American College of Radiology's (2009) guidelines for obtaining radiographs for scoliosis in children recommends for the scoliotic - films distance to be 1,80 meters. Normal values used for the transverse diameter of the ribcage in children aged 6-12 years were those reported by Grivas in 1988. RESULTS: Using the Euclidean geometry, it is shown that in a normal 12-year old child d1/d2 = 1.073 provided that the distance ΔZ ≈ 12cm (11,84) and EA = 180cm, with transverse ribcage diameter of the child 22 cm. CONCLUSIONS: This validity study demonstrates that the DRCS is substantially true and the RI is not practically affected by the distance between the radiation source and the irradiated child. The RI is valid and may be used to evaluate the effect of surgical or conservative treatment on the rib cage deformity (hump) in children with IS. It is noted that RI is a simple method and a safe reproducible way to assess the rib hump deformity based on lateral radiographs, without the need for any other special radiographs and exposure to additional radiation.