RESUMO
The Covid-19 a pandemic infectious disease and affected life across the world resulting in over 188.65 million confirmed cases across 223 countries, territories and areas with 4.06 million deaths. It is caused by a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and spike (S) protein of SARS-CoV-2, which plays a key role in the receptor recognition and cell membrane fusion process, is composed of two subunits, S1 and S2. The S1 subunit contains a receptor-binding domain (RBD) that recognizes and binds to the host receptor angiotensin-converting enzyme 2 (ACE2), while the S2 subunit mediates viral cell membrane fusion. Hence, it is a key target for developing neutralizing antibodies. Here, we have performed phylogenetic analysis and structural modeling of the SARS-CoV-2 spike glycoprotein, which is found highly conserved. The overall percent protein sequence identity from the SARS-CoV-2 spike protein sequences from the NCBI database was 99.68%. The functional domains of the S protein reveal that the S1 subunit was highly conserved (99.70%) than the S2 subunit (99.66%). Further, the 319-541 residues (RBD) of amino acids within the S1 domain were 100% similar among the spike protein. The 3D modeling of SARS-CoV-2 spike glycoprotein indicated that S protein has four domains with five protein units and the S1 subunit from 1 to 289 amino acid of domain 1 is highly conserved without any change in the ligand interaction site. This analysis clearly suggests that the S1 subunit (RBD 319-541) can be used as a target region for stable and safe vaccine development.
RESUMO
BACKGROUND: To evaluate the feasibility, safety, and outcome of laparoscopic kidney transplantation (LKT) after retroperitoneoscopic living-donor nephrectomy. METHODS: Between February 2010 and January 2012, a total of 217 renal transplantations were performed from living donors by a single surgical unit. All living-donor nephrectomies were performed by retroperitoneoscopic approach. Recipient surgery was performed either laparoscopically (n=72) or by conventional open approach (n=145). In the LKT group, a 5 to 6 cm Pfannenstiel incision was placed and the kidney was dropped into abdomen. Renal vessels were anastomosed by freehand suturing technique. Calcineurin inhibitor-based immunosuppressants were given. RESULTS: The mean operative time was 223.8 and 175.7 min (P=0.07) and the rewarming time was 60.3 and 30.3 min (P=0.03) in the LKT and open kidney transplantation (OKT) groups, respectively. The estimated glomerular filtration rate value on days 7 and 30 was significantly less in the LKT group, but no difference was found at 3, 6, 12, and 18 months. The mean wound length was 5.5 and 17.8 cm (P=0.0001) and the analgesic requirement was 1.4 and 3.2 mg morphine equivalent in first 24 hr (P=0.005) in the LKT and OKT groups, respectively. In the LKT group, four cases required conversion to open surgery due to vascular complications and one for urinary leak. Kaplan-Meier curve shows 86.5% and 94.6% (P=0.086) and patient survival is 94.1% and 94.7% (P=0.745) at 22.3 months of follow-up. CONCLUSIONS: LKT after living-donor nephrectomy is feasible, but it has steep learning curve. Graft fixation with peritoneal fold is necessary to avoid torsion and related graft loss. Pain after LKT is significantly less compared with conventional OKT.
