Mpox Outbreak - Los Angeles County, California, May 4-August 17, 2023.

Since May 2022, approximately 2,500 mpox cases have been reported in Los Angeles County (LAC), California. Beginning in May 2023, the LAC Department of Public Health observed a consistent increase in mpox cases after a prolonged period of low incidence. A total of 56 cases were identified during May 4-August 17, 2023. A minority of mpox patients were fully vaccinated (29%). One patient was hospitalized; no deaths were reported. Two cases of reinfection occurred, both of which were associated with mild illness. The increasing number of cases during this period was significant, as few other health departments in the United States reported an increase in mpox cases during the same period. The outbreak spread similarly to the 2022 U.S. mpox outbreak, mainly through sexual contact among gay, bisexual, and other men who have sex with men. Vaccination against mpox became available in June 2022 and has been shown to be effective at preventing mpox disease. This outbreak was substantially smaller than the 2022 mpox outbreak in LAC (2,280 cases); possible explanations for the lower case count include increased immunity provided from vaccination against mpox and population immunity from previous infections. Nonetheless, mpox continues to spread within LAC, and preventive measures, such as receipt of JYNNEOS vaccination, are recommended for persons at risk of Monkeypox virus exposure.

Ensemble-based enzyme design can recapitulate the effects of laboratory directed evolution in silico.

The creation of artificial enzymes is a key objective of computational protein design. Although de novo enzymes have been successfully designed, these exhibit low catalytic efficiencies, requiring directed evolution to improve activity. Here, we use room-temperature X-ray crystallography to study changes in the conformational ensemble during evolution of the designed Kemp eliminase HG3 (kcat/KM 146 M-1s-1). We observe that catalytic residues are increasingly rigidified, the active site becomes better pre-organized, and its entrance is widened. Based on these observations, we engineer HG4, an efficient biocatalyst (kcat/KM 103,000 M-1s-1) containing key first and second-shell mutations found during evolution. HG4 structures reveal that its active site is pre-organized and rigidified for efficient catalysis. Our results show how directed evolution circumvents challenges inherent to enzyme design by shifting conformational ensembles to favor catalytically-productive sub-states, and suggest improvements to the design methodology that incorporate ensemble modeling of crystallographic data.

Cytoreductive surgery and intraperitoneal hyperthermic chemotherapy in the treatment of peritoneal carcinomatosis.

PURPOSE: Cytoreductive surgery (CS) and intraperitoneal hyperthermic chemotherapy (IPHC) in the treatment of peritoneal carcinomatosis (PC) in 15 patients are described. SUMMARY: Fifteen patients with PC who were treated with CS and IPHC were retrospectively identified between January 2002 and December 2006. All patients underwent cytoreduction immediately followed by IPHC with mitomycin or cisplatin. The time between undergoing CS and IPHC and the date of the last follow-up appointment or the date of death was used to calculate survival data for each patient. Nine patients had complete cytoreduction, and all but one patient had evidence of invasive disease at the time of surgery. Eleven patients required concomitant bowel resection at the time of debulking. Thirteen patients required blood transfusions during the perioperative period. Nine patients were discharged home, and four were discharged to a rehabilitation facility. Two patients died during the perioperative hospital admission, both of whom had a preoperative Eastern Cooperative Oncology Group (ECOG) performance status score of 2. The median survival time was 8.4 months, similar to the findings of previously published studies. Further studies are needed to see if tumor type, ECOG performance status score, degree of cytoreduction, and the chemotherapy agent used in IPHC can be correlated to quality of life and survival in patients with heterogeneous primary sources of intraabdominal malignancies. CONCLUSION: Combination treatment with CS followed by IPHC in 15 patients with heterogeneous primary sources of intraabdominal malignancies resulted in a median survival time of 8.4 months.

Sequence and phylogenetic analyses of the twin-arginine targeting (Tat) protein export system.

Twin-arginine targeting (Tat) protein secretion systems consist of two protein types, members of the TatA and TatC families. Homologues of these proteins are found in many archaea, bacteria, chloroplasts and mitochondria. Every prokaryotic organism with a fully sequenced genome exhibits either neither family member, or between one and three paralogues of these two family members. The Arabidopsis thaliana genome encodes three of each. Although many mitochondrially encoded TatC homologues have been identified, corresponding TatA homologues have not been found in this organelle. Phylogenetic analyses reveal that most prokaryotic Tat systems consist of one TatC homologue and two sequence-divergent TatA homologues (TatA and TatB). When only one TatA homologue is present, TatB is missing, and when three TatA homologues are present, the third one arose by duplication of TatA, not TatB. Further, homologues most resembling TatB are more sequence-divergent than those more closely resembling TatA. In contrast to the TatA family, the TatC family shows phylogenetic clustering in strict accordance with organismal type. These results are discussed in terms of their probable structural, functional and evolutionary significance.