SARS-CoV-2 genomes from Saudi Arabia implicate nucleocapsid mutations in host response and increased viral load

Monitoring SARS-CoV-2 spread and evolution through genome sequencing is essential in handling the COVID-19 pandemic. Here, we sequenced 892 SARS-CoV-2 genomes collected from patients in Saudi Arabia from March to August 2020. We show that two consecutive mutations (R203K/G204R) in the nucleocapsid (N) protein are associated with higher viral loads in COVID-19 patients. Our comparative biochemical analysis reveals that the mutant N protein displays enhanced viral RNA binding and differential interaction with key host proteins. We found increased interaction of GSK3A kinase simultaneously with hyper-phosphorylation of the adjacent serine site (S206) in the mutant N protein. Furthermore, the host cell transcriptome analysis suggests that the mutant N protein produces dysregulated interferon response genes. Here, we provide crucial information in linking the R203K/G204R mutations in the N protein to modulations of host-virus interactions and underline the potential of the nucleocapsid protein as a drug target during infection.

Results of suture of the radial, median, and ulnar nerves after missile injury below the axilla

OBJECTIVE

To evaluate the functional outcome and return to work after suture of upper extremity nerves after low-velocity missile injury.

METHODS

Forty-one patients had suture of the radial, median, and/or ulnar nerves between the wrist and axilla, 3 to 17 weeks after low-velocity missile injury. Postoperative functional outcome was good if no supplemental techniques (permanent splints, tendon or muscle transfer, fusion) were required, fair if supplemental techniques were required to restore a functional hand, and poor if the hand was severely deformed. The follow-up period was 14 to 38 months.

RESULTS

Supplemental techniques followed the suture of 11% of radial, 45% of median, 72% of ulnar, and 100% of combined median and ulnar nerve injury. After suture +/- supplemental techniques, patients returned to work in 100% of radial, 55% of median, 57% of ulnar, and 0% of combined median and ulnar nerve injuries.

CONCLUSION

Nerve suture between the wrist and axilla and supplemental techniques achieve functional recovery in the majority of patients after missile injury with good expectations for return to work, except in combined median and ulnar nerve injuries.

Results of suture of the sciatic nerve after missile injury

OBJECTIVE

To evaluate functional recovery after suture of the sciatic nerve after missile injury.

METHODS

We reviewed the outcome of 23 adults and four children who had the sciatic nerve sutured above the knee 3 to 14 weeks after missile injury and who were followed for 14 to 36 months.

RESULTS

In adults, useful motor recovery was significantly better after suture of tibial (83%) than peroneal (39%) nerves, after suture of nerves at the thigh (71%) than at the buttock (31%) level, and after end-to-end anastomosis (74%) than grafting (39%). Useful sensory function was recovered in 78% of tibial nerves. Fifty-seven percent of adults walked wearing special shoes or pads. Significantly better recovery occurred in children, who all walked with normal footwear.

CONCLUSION

We advocate exploration of the sciatic nerve at any level within 3 months if no spontaneous recovery occurs after a missile injury. We do not advocate exploration of the sciatic nerve at the buttock level if only peroneal function is lost except in children.

Osteosynthesis of the cervical spine with an anterior plate

Osteosynthesis with an anterior plate is indicated for stabilization of the cervical spine. It is used for reconstruction of the vertebral body following corpectomy and for cervical instability due to fractures, fracture-dislocations, and post-laminectomy. In these situations, a well-keyed anterior graft or posterior fusion alone may be inadequate to attain stability. The authors retrospectively review 25 cases of osteosynthesis of the cervical spine using the AO H-plate. All the patients were stable enough postoperatively to allow early mobilization with a cervicothoracic orthosis. Average follow up was 31.2 months. All the grafts fused; however, complications occurred in 36% of the cases. The majority of these complications did not affect the long-term clinical result. This method involves potential risks to the spinal cord, esophagus, carotid structures, and laryngeal nerve. It should therefore be used in carefully selected cases.

Herniation of the spinal cord. Case report

Herniation of the spinal cord, or displacement of the cord outside the dura, is so rare that only 13 cases have been reported in the literature. The authors report a new case of spontaneous herniation of the spinal cord in a 38-year-old man who presented with lower left limb paresis and Brown-Séquard syndrome, with a T-8 sensory level. Displacement of the spinal cord was noted on computerized tomography following myelography and on magnetic resonance imaging. The herniated cord was confirmed at operation and reduced intradurally. Postoperatively, the patient showed complete neurological recovery. Based on a review of the literature, herniation of the spinal cord may be classified as spontaneous, iatrogenic, or traumatic. At cervical levels, the spinal cord has herniated into an iatrogenic pseudomeningocele located dorsally. At thoracic levels, spinal cord herniations were reported to be in a preexisting extradural arachnoid cyst located ventrally. The authors propose a pathogenesis for spinal cord herniation based on abnormal positioning of the spinal cord in the dural sleeve and the known anteroposterior movements of the cord that occur with cardiac and respiratory pulsations. The presence of a dural defect situated on the concavity of the spinal curvature is a prerequisite for this rare condition. As adhesions develop between the cord and the edges of the dural defect, cerebrospinal fluid pulsations push the cord into a preexisting cyst. The authors suggest modifying the classification by Nabors, et al., of spinal meningeal cysts to include this mechanism of spinal cord herniation. This diagnosis should also be considered in the differential diagnosis of myelopathy in the absence of a mass lesion.

Surgical resection of third ventricle colloid cysts. Preliminary results comparing transcallosal microsurgery with endoscopy

It is still not determined which is the best surgical option for third ventricle colloid cysts. Since 1990, the authors have used a steerable fiberscope to remove colloid cysts in seven patients and have performed microsurgery via a transcallosal approach in eight patients. The two techniques were compared for operating time, length of hospital stay, incidence of complications, recurrence, and hydrocephalus, and days spent recuperating before return to work to determine if endoscopic removal of colloid cysts is a safe and effective alternative to microsurgery. Statistical analysis was adjusted for age, sex, and presenting symptoms. Microsurgical cases averaged 206 minutes of operating time whereas endoscopic cases averaged 127 minutes (p = 0.01). For combined days spent in the intensive care unit and on the ward, the patients averaged 9.5 days after microsurgery and 4 days after endoscopy (p = 0.05). Postoperative complications occurred in five of eight patients after microsurgery and in one of seven patients after endoscopy (p = 0.09); complications were transient and primarily related to short-term memory loss. In all patients, preoperative symptoms resolved and the cysts have not recurred. Postoperatively, one patient required a ventriculoperitoneal shunt after microsurgery but all patients were shunt-independent after endoscopy. Patients returned to work an average of 59 days after discharge following microsurgery compared with an average of 26 days after endoscopy (p = 0.05). Compared with transcallosal microsurgery for the removal of colloid cysts, these preliminary results show that a steerable endoscope reduced operating time and that patients spent fewer days in the hospital and returned to work sooner after endoscopy.