ABSTRACT
While traditional methods for studying large DNA viruses allow the creation of individual mutants, CRISPR/Cas9 can be used to rapidly create thousands of mutant dsDNA viruses in parallel, enabling the pooled screening of entire viral genomes. Here, we applied this approach to Kaposi's sarcoma-associated herpesvirus (KSHV) by designing a sgRNA library containing all possible ~22,000 guides targeting the 154 kilobase viral genome, corresponding to one cut site approximately every 8 base pairs. We used the library to profile viral sequences involved in transcriptional activation of late genes, whose regulation involves several well characterized features including dependence on viral DNA replication and a known set of viral transcriptional activators. Upon phenotyping all possible Cas9-targeted viruses for transcription of KSHV late genes we recovered these established regulators and identified a new required factor (ORF46), highlighting the utility of the screening pipeline. By performing targeted deep sequencing of the viral genome to distinguish between knock-out and in-frame alleles created by Cas9, we identify the DNA binding but not catalytic domain of ORF46 to be required for viral DNA replication and thus late gene expression. Our pooled Cas9 tiling screen followed by targeted deep viral sequencing represents a two-tiered screening paradigm that may be widely applicable to dsDNA viruses.
Subject(s)
Gene Expression Regulation, Viral/physiology , Genes, Viral/genetics , Herpesvirus 8, Human/genetics , CRISPR-Cas Systems , HEK293 Cells , HumansABSTRACT
PURPOSE OF REVIEW: The anesthetic management of patients with Moyamoya disease (MMD) is challenging and continues to evolve. The goal of this review is to provide updated recommendations on the anesthetic management of adult MMD patients based on the relevant existing literature. RECENT FINDINGS: Key findings include the importance of aggressive hydration preoperatively to sustain cerebral perfusion. Hypertension induced intraoperatively may prevent cerebral hypoperfusion. Vigilance against cerebral hyperperfusion after revascularization is necessary, with specific blood pressure targets recommended. Fluid management should aim for normovolemia to mild hypervolemia. Maintaining body temperature helps prevent cerebral vasospasm induced by hypothermia. Maintaining adequate oxygen supply during surgery is crucial. In cases of ischemic stroke, managing hematocrit and oxygen carrying capacity is essential to prevent further ischemia. Extubation decisions should consider baseline neurological function, while postoperative normocapnia helps prevent cerebral hyperperfusion and hypertension. In intensive care, cautious blood pressure management is crucial to prevent secondary complications. SUMMARY: Strategies in the preoperative, intraoperative, and postoperative anesthetic management of MMD patients should aim to maintain adequate cerebral perfusion to prevent cerebral ischemia.
ABSTRACT
BACKGROUND: To treat Neisseria gonorrhoeae infection, the Centers for Disease Control and Prevention recommends a single oral dose of cefixime as an alternative to injectable ceftriaxone. METHODS: We conducted a systematic review and meta-analysis to describe the effectiveness of cefixime in treating N. gonorrhoeae infection at 3 different anatomic sites.We searched PubMed and Embase database to abstract treatment success rates and cefixime dosage/frequency for studies that reported the anatomical site of infection. We included reports published between January 1, 1980, and December 7, 2021. Twenty studies published between 1989 and 2015 were included in our meta-analysis. We calculated pooled treatment success percentages and 95% confidence intervals (CIs) using random-effects models. RESULTS: Of patients who received a 400-mg single dose of cefixime, 824 of 846 (97%; 95% CI, 96%-98%) patients with urogenital infection, 107 of 112 (97%; 95% CI, 84%-100%) patients with rectal infection, and 202 of 242 (89%; 95% CI, 76%-96%) patients with pharyngeal infection were cured. Of patients who received an 800-mg single dose of cefixime, 295 of 301 (98%; 95% CI, 96%-99%) patients with urogenital infection and 21 of 26 (81%; 95% CI, 61%-92%) patients with pharyngeal infection were cured. CONCLUSIONS: Our meta-analysis found that cefixime is highly effective at treating urogenital infections and less effective at treating pharyngeal infections. We recommend more investigation into the effectiveness of cefixime in treating rectal infections and studying multidose therapy for the cefixime treatment of pharyngeal infection.
Subject(s)
Gonorrhea , Humans , Cefixime/pharmacology , Gonorrhea/drug therapy , Anti-Bacterial Agents/pharmacology , Ceftriaxone/therapeutic use , Treatment Outcome , Neisseria gonorrhoeae , Microbial Sensitivity TestsABSTRACT
Viruses encode transcriptional regulatory proteins critical for controlling viral and host gene expression. Given their multifunctional nature and high sequence divergence, it is unclear which viral proteins can affect transcription and which specific sequences contribute to this function. Using a high-throughput assay, we measured the transcriptional regulatory potential of over 60,000 protein tiles across â¼1,500 proteins from 11 coronaviruses and all nine human herpesviruses. We discovered hundreds of transcriptional effector domains, including a conserved repression domain in all coronavirus Spike homologs, dual activation-repression domains in viral interferon regulatory factors (VIRFs), and an activation domain in six herpesvirus homologs of the single-stranded DNA-binding protein that we show is important for viral replication and late gene expression in Kaposi's sarcoma-associated herpesvirus (KSHV). For the effector domains we identified, we investigated their mechanisms via high-throughput sequence and chemical perturbations, pinpointing sequence motifs essential for function. This work massively expands viral protein annotations, serving as a springboard for studying their biological and health implications and providing new candidates for compact gene regulation tools.
Subject(s)
Herpesvirus 8, Human , Humans , Herpesvirus 8, Human/genetics , Herpesvirus 8, Human/metabolism , Virus Replication/genetics , Gene Expression RegulationABSTRACT
Bouveret syndrome, a specific form of gallstone ileus, is the obstruction of the gastric outlet by a gallstone, which can enter the duodenum through a fistula. While the average age of individuals with Bouveret syndrome is 74 years, our patient was 42 years of age at the time of operation, significantly younger than the average patient afflicted with this condition. In the treatment of our patient's condition, the operation conducted entailed a partial duodenectomy, gastrojejunostomy, cholecystectomy, common bile duct exploration, extraction of bile duct stones, and insertion of a t-tube in the bile duct. The patient was found to be in healthy condition upon check-up six months after the operation. The outcome of our case suggests that younger Bouveret patients can safely undergo multiple surgical procedures in the treatment of Bouveret syndrome. Our case also suggests that a cholecystectomy and the removal of the obstructing gallstone can both be carried out within one operation, although coupling these two procedures in one operation might be riskier for patients within the normal age range of Bouveret syndrome. We also suggest that fistula repair be carried out for younger Bouveret patients in particular and that the patient be subjected to a CT scan in the diagnosis of Bouveret syndrome when this condition is suspected.