N2-Amino-Modifier C6 dG is designed for automatic synthesis. During oligonucleotide synthesis, the addition of the amino modifier dG can replace the dG residue to functionalize the target oligonucleotide.
Reference Reading
1. Sonoanatomy revisited: the long thoracic nerve
Ke-Vin Chang, Wei-Ting Wu, Kamal Mezian, Ondřej Naňka, Levent Özçakar. Med Ultrason. 2019 Aug 31;21(3):349-352. doi: 10.11152/mu-1952.
The long thoracic nerve (LTN) arises from the C5, C6 and C7 roots and innervates the serratus anterior muscle. Scapular winging is the landmark manifestation of LTN neuropathy and may develop after an accidental injury during selective cervical nerve root or inter-scalene brachial plexus blocks. Although its sonoanatomy has been described in the previous literature, how to gradually identify the entire nerve course has rarely been discussed. In this regard, the present paper aims to elaborate the scanning method of the LTN from its origin to its distal segment.
2. Cervicobrachial neuralgia due to vertebral artery loop
Marine Rigal, Sylvain Portet, Emmanuel Jouanneau, Roberto Riva, Omer Eker, Timothée Jacquesson. Surg Radiol Anat. 2022 Feb;44(2):223-226. doi: 10.1007/s00276-022-02885-z.
The main anatomic variations should be taught along with the classical anatomy curriculum, since they can mislead both diagnosis and treatment. We report here a clinical and radiological case of left C6 cervicobrachial neuralgia recurrence due to a vertebral artery loop, we then describe 13 published cases of such neurovascular conflicts. A 51-year-old woman suffered from recurrence of C6 cervicobrachial neuralgia after an initial C5-C6 decompression-fusion. Additional cervical angio-MR and CT scans found a tortuous aspect of the left vertebral artery that came into conflict with the left C6 spinal root, just after its emergence of the C5-C6 intervertebral foramen. A large posterior decompression was performed including a C5 and C6 left lateral mass resection to enlarge the foraminal space. The vertebral artery was kept in place. The patient reported a slow but consistent decrease in pain that disappeared after 3 months. Thirteen cases of a compressive vertebral loop are thereafter detailed. Vascular precursors disarrangements can lead to a vertebral artery loop in contact with emerging cervical roots and potential clinical impact. This differential diagnosis should be considered for cervico-brachial neuralgia management. Moreover, the present case highlights the key role of a careful preoperative imaging assessment, as well as the need for robust knowledge of anatomy.
3. Fluoroquinolones as imaging agents for bacterial infection
Syed Ali Raza Naqvi, Karl Drlica. Dalton Trans. 2017 Oct 31;46(42):14452-14460. doi: 10.1039/c7dt01189j.
Diagnosis of deep-seated bacterial infection is difficult, as neither standard anatomical imaging nor radiolabeled, autologous leukocytes distinguish sterile inflammation from infection. Two recent imaging efforts are receiving attention: (1) radioactive derivatives of sorbitol show good specificity with Gram-negative bacterial infections, and (2) success in combining anatomical and functional imaging for cancer diagnosis has rekindled interest in 99mTc-fluoroquinolone-based imaging. With the latter, computed tomography (CT) would be combined with single-photon-emission-computed tomography (SPECT) to detect 99mTc-fluoroquinolone-bacterial interactions. The present minireview provides a framework for advancing fluoroquinolone-based imaging by identifying gaps in our understanding of the process. One issue is the reliance of 99mTc labeling on the reduction of sodium pertechnetate, which can lead to colloid formation and loss of specificity. Specificity problems may be reduced by altering the quinolone structure (for example, switching from ciprofloxacin to sitafloxacin). Another issue is the uncharacterized nature of 99mTc-ciprofloxacin binding to, or sequestration in, bacteria: specific interactions with DNA gyrase, an intracellular fluoroquinolone target, are unlikely. Labeling with 68Ga rather than 99mTc enables detection by positron emission tomography, but with similar biological uncertainties. Replacing the C6-F of the fluoroquinolone with 18F provides an alternative to pertechnetate and gallium that may lead to imaging based on drug interactions with gyrase. Gyrase-based imaging requires knowledge of fluoroquinolone action, which we update. We conclude that quinolone-based probes show promise for the diagnosis of infection, but improvements in specificity and sensitivity are needed. These improvements include the optimization of the quinolone structure; such chemistry efforts can be accelerated by refining microbiological assays.