METHOD: This systematic review was conducted according to the recommendations of the Cochrane Handbook for Reviews of Interventions and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. PubMed, Embase, and the Cochrane Library were searched to identify eligible studies. The main outcome variable was the preoperative assessment of patterns of blood supply to the colon and the impact of these patterns on anastomosis leak. The quality of bias control in the studies was assessed using the Newcastle-Ottawa Scale. Due to the heterogeneous nature of the included studies, no meta-analysis was conducted.
RESULTS: Fourteen studies were included. The study covered a period from 1978 to 2021. A significant degree of variation in the arterial and/or venous supply of the colon and rectum might influence anastomosis leak rates. Calcification in great blood vessels can be assessed with a preoperative computed tomography scan, which may predict anastomosis leak rates. This is supported by many experimental studies that showed increased rates of anastomosis leak after preoperative ischemia, but the extent of this impact is not well established.
CONCLUSION: Preoperative assessment of blood supply to the colon and rectum might help in planning the surgical intervention to reduce anastomosis leak rates. Calcium scoring of major arteries might predict anastomosis leak and thus play a crucial role in intraoperative decision-making.
METHODS: Using CRISPR/Cas9 gene editing two chimeric P. falciparum parasites, were generated, where the pfcsp gene has been replaced by either one of the two major pvcsp alleles, VK210 or VK247. In addition, a P. falciparum parasite line that lacks CSP expression was also generated. These parasite lines have been analysed for sporozoite production in An. stephensi mosquitoes.
RESULTS: The two chimeric Pf-PvCSP lines exhibit normal asexual and sexual blood stage development in vitro and produce sporozoite-containing oocysts in An. stephensi mosquitoes. Expression of the corresponding PvCSP was confirmed in oocyst-derived Pf-PvCSP sporozoites. However, most oocysts degenerate before sporozoite formation and sporozoites were not found in either the mosquito haemocoel or salivary glands. Unlike the chimeric Pf-PvCSP parasites, oocysts of P. falciparum parasites lacking CSP expression do not produce sporozoites.
CONCLUSIONS: Chimeric P. falciparum parasites expressing P. vivax circumsporozoite protein fail to produce salivary gland sporozoites. Combined, these studies show that while PvCSP can partially complement the function of PfCSP, species-specific features of CSP govern full sporozoite maturation and development in the two human malaria parasites.