Development of Inactivated FAKHRAVAC® Vaccine against SARS-CoV-2 Virus: Preclinical Study in Animal Models.

The recent viral infection disease pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a global public health crisis. Iran, as one of the countries that reported over five million infected cases by September 2021, has been concerned with the urgent development of effective vaccines against SARS-CoV-2. In this paper, we report the results of a study on potency and safety of an inactivated SARS-CoV-2 vaccine candidate (FAKHRAVAC) in a preclinical study so as to confirm its potential for further clinical evaluation. Here, we developed a pilot-scale production of FAKHRAVAC, a purified inactivated SARS-CoV-2 virus vaccine candidate that induces neutralizing antibodies in Balb/c mice, guinea pigs, rabbits, and non-human primates (Rhesus macaques-RM). After obtaining ethical code of IR.IUMS.REC.1399.566, immunizations of animals were conducted by using either of three different vaccine dilutions; High (H): 10 µg/dose, Medium (M): 5 µg/dose, and Low (L): 1 µg/dose, respectively. In the process of screening for viral seeds, viral strains that resulted in the most severe clinical manifestation in patients have been isolated for vaccine development. The viral seed produced the optimal immunity against SARS-CoV-2 virus, which suggests a possible broader neutralizing ability against SARS-CoV-2 strains. The seroconversion rate at the H-, M-, and L-dose groups of all tested animals reached 100% by 28 days after immunization. These data support the eligibility of FAKHRAVAC vaccine candidate for further evaluation in a clinical trial.

Expression and purification of recombinant TAT-BoNT/A(1-448) under denaturing and native conditions.

Botulinum toxin type A can temporarily inhibit muscle contraction. Currently, physicians administer this toxin as a bio-drug in treatment of some muscle contraction disorders. TAT-BoNT/A(1-448) is a functional recombinant protein derived from botulinum toxin light chain. Unlike the full length botulinum toxin, TAT-BoNT/A(1-448) is a self-permeable molecule which can pass through bio-surfaces so can be used as a topical therapeutic agent without injection. To maintain the functionality of TAT-BoNT/A(1-448), it is necessary to restore its normal folding upon expression and purification. In this study, we have investigated and optimized expression conditions for this novel recombinant protein. Under denaturing condition (1 mM IPTG, at 37°C), the chimeric protein was produced as inclusion body and required to be purified using denaturing agents (e.g. urea). Yet, lower incubation temperature (18°C) and less IPTG concentration (0.5 mM) induce a protein under native condition. In such condition, about 60% of the chimeric protein was expressed in soluble form.

TAT-BoNT/A(1₋448), a novel fusion protein as a therapeutic agent: analysis of transcutaneous delivery and enzyme activity.

Botulinum neurotoxin type A (BoNT/A) has been used as an injectable therapeutic agent for the treatment of some abnormal muscle contractions. In this study, TAT(47-57) peptide, a cell-penetrating peptide, was fused with the catalytic domain of BoNT/A for therapeutic purposes. HeLa and BE(2)-C cell lines were treated separately with purified TAT-BoNT/A(1-448) recombinant protein, and transduction of protein was analyzed by western blotting. Also, transcutaneous delivery through mouse skin surface was evaluated by immunohistochemistry. The in vitro catalytic activity of TAT-BoNT/A(1-448) was evaluated by HPLC. The presence of recombinant protein was detected in both of the cell lines as well as mouse skin cryosections after 60 and 120 min of incubation. The concentration of intracellular proteins was increased over time. HPLC analysis showed that this fusion protein has a biological activity 1.5 times as much as the full-length BoNT/A(1-448) protein. TAT-BoNT/A(1-448) fusion protein is biologically active and can transmit through living cells in vitro and in vivo successfully and more effectively compared with BoNT/A(1-448) protein as control.

Safety of fluoroscopy guided percutaneous access to the thoracic spine.

BACKGROUND: Fluoroscopy-guided percutaneous access to thoracic vertebrae is technically demanding due to the complex radiological anatomy and close proximity of the spinal cord, major vessels and pleural cavity. There is a trend towards computed tomography (CT) guidance due to a perceived reduction in the risk of spinal canal intrusion by instrumentation causing neurological injury. Due to limited access to CT guidance, there is a need for safe fluoroscopy-guided percutaneous access to the thoracic spine. PURPOSE: To evaluate the safety of a strict radio-anatomical protocol in avoiding access-related neurological complications due to tool misplacement in fluoroscopy-guided percutaneous procedures on the thoracic spine. METHOD: A combined two-surgeon prospective case series of 444 procedures (biopsy, vertebroplasty or kyphoplasty) covering all thoracic vertebral levels T1-T12. Clinical examination and routine observations were used to identify access-related complications including neurological, vascular and visceral injury using physiological parameters. RESULTS: No patient in our series was identified to have sustained a neurological deficit or deterioration of preoperative neurological status. CONCLUSION: Percutaneous access to the thoracic spine using fluoroscopic guidance is safe. The crucial step of the protocol is not to advance the tool beyond the medial pedicle wall on the anterior-posterior projection until the tip of the instrument has reached the posterior vertebral cortex on the lateral projection.

Closed tibial fracture associated with laceration of tibialis anterior tendon.

Traumatic laceration of the tibialis anterior tendon is a rare finding. To the best of our knowledge, 4 such cases have been reported in the surgical literature, and 3 of these were missed upon initial clinical examination. We present the case of a 26-year-old male motorcyclist who sustained an acute laceration of the tibialis anterior tendon in association with closed fractures of the tibia and fibula. The laceration was initially not included in the diagnosis, because weak ankle dorsiflexion was attributed to antalgic guarding. The primary aim of this report is to emphasize the possibility of tibialis anterior tendon laceration in association with closed fracture of the tibia, and to encourage surgeons to maintain a high index of suspicion for this particular defect. Furthermore, we encourage surgeons to undertake a meticulous physical examination and, if warranted, obtain ancillary diagnostic images, such as magnetic resonance images, in order to accurately diagnose and determine the optimal course of treatment.