The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

Transcriptional and Metabolic Responses of Bacillus subtilis to the Availability of Organic Acids: Transcription Regulation Is Important but Not Sufficient To Account for Metabolic Adaptation

The soil bacterium Bacillus subtilis can use sugars or organic acids as sources of carbon and energy. These nutrients are metabolized by glycolysis, the pentose phosphate pathway, and the Krebs citric acid cycle. While the response of B. subtilis to the availability of sugars is well understood, much less is known about the changes in metabolism if organic acids feeding into the Krebs cycle are provided. If B. subtilis is supplied with succinate and glutamate in addition to glucose, the cells readjust their metabolism as determined by transcriptome and metabolic flux analyses. The portion of glucose-6-phosphate that feeds into the pentose phosphate pathway is significantly increased in the presence of organic acids. Similarly, important changes were detected at the level of pyruvate and acetyl coenzyme A (acetyl-CoA). In the presence of organic acids, oxaloacetate formation is strongly reduced, whereas the formation of lactate is significantly increased. The alsSD operon required for acetoin formation is strongly induced in the presence of organic acids; however, no acetoin formation was observed. The recently discovered phosphorylation of acetolactate decarboxylase may provide an additional level of control of metabolism. In the presence of organic acids, both types of analyses suggest that acetyl-CoA was catabolized to acetate rather than used for feeding the Krebs cycle. Our results suggest that future work has to concentrate on the posttranslational mechanisms of metabolic regulation

Treatment strategies for recurrent and residual aneurysms after Woven Endobridge implantation

Background Woven Endobridge (WEB) embolization is a safe and efficient technique for endovascular treatment of intracranial aneurysms. However, the management of aneurysm recurrence after WEB placement has not been well described to date. We present our multicenter experience of endovascular retreatment of aneurysm recurrence after WEB implantation. Methods This is a multicenter study of patients who underwent endovascular retreatment after WEB implantation in three German tertiary care centers. Treatment strategies, complications, and angiographic outcome were retrospectively assessed. Results A mong 122 aneurysms treated with the WEB device, 15 were retreated. Of these, six were initially treated with the WEB only, two were pretreated by coiling, and seven large aneurysms were treated in a multimodality approach. Ten were true aneurysm remnants and five were neck remnants. The reasons for retreatment were WEB migration (n=6), initial incomplete occlusion (n=5), and WEB compression (n=4). Retreatment strategies included coiling (n=4), stent-assisted coiling (n=7), flow diversion (n=3), and placement of an additional WEB (n=1). All procedures were technically successful and there were no procedure-related complications. Among 11 patients available for follow-up after retreatment, three were retreated again. At last angiographic follow-up, available in 11/15 cases at a median of 23 months, complete occlusion was obtained in eight cases and neck remnants in three. Conclusions This pilot study shows that endovascular retreatment of recurrent or residual aneurysms after WEB implantation can be done safely and can achieve adequate occlusion rates

Essentiality of c-di-AMP in Bacillus subtilis: Bypassing mutations converge in potassium and glutamate homeostasis.

In order to adjust to changing environmental conditions, bacteria use nucleotide second messengers to transduce external signals and translate them into a specific cellular response. Cyclic di-adenosine monophosphate (c-di-AMP) is the only known essential nucleotide second messenger. In addition to the well-established role of this second messenger in the control of potassium homeostasis, we observed that glutamate is as toxic as potassium for a c-di-AMP-free strain of the Gram-positive model bacterium Bacillus subtilis. In this work, we isolated suppressor mutants that allow growth of a c-di-AMP-free strain under these toxic conditions. Characterization of glutamate resistant suppressors revealed that they contain pairs of mutations, in most cases affecting glutamate and potassium homeostasis. Among these mutations, several independent mutations affected a novel glutamate transporter, AimA (Amino acid importer A, formerly YbeC). This protein is the major transporter for glutamate and serine in B. subtilis. Unexpectedly, some of the isolated suppressor mutants could suppress glutamate toxicity by a combination of mutations that affect phospholipid biosynthesis and a specific gain-of-function mutation of a mechanosensitive channel of small conductance (YfkC) resulting in the acquisition of a device for glutamate export. Cultivation of the c-di-AMP-free strain on complex medium was an even greater challenge because the amounts of potassium, glutamate, and other osmolytes are substantially higher than in minimal medium. Suppressor mutants viable on complex medium could only be isolated under anaerobic conditions if one of the two c-di-AMP receptor proteins, DarA or DarB, was absent. Also on complex medium, potassium and osmolyte toxicity are the major bottlenecks for the growth of B. subtilis in the absence of c-di-AMP. Our results indicate that the essentiality of c-di-AMP in B. subtilis is caused by the global impact of the second messenger nucleotide on different aspects of cellular physiology

The YmdB Phosphodiesterase Is a Global Regulator of Late Adaptive Responses in Bacillus subtilis

Bacillus subtilis mutants lacking ymdB are unable to form biofilms, exhibit a strong overexpression of the flagellin gene hag, and are deficient in SlrR, a SinR antagonist. Here, we report the functional and structural characterization of YmdB, and we find that YmdB is a phosphodiesterase with activity against 2′,3′- and 3′,5′-cyclic nucleotide monophosphates. The structure of YmdB reveals that the enzyme adopts a conserved phosphodiesterase fold with a binuclear metal center. Mutagenesis of a catalytically crucial residue demonstrates that the enzymatic activity of YmdB is essential for biofilm formation. The deletion of ymdB affects the expression of more than 800 genes; the levels of the σD-dependent motility regulon and several sporulation genes are increased, and the levels of the SinR-repressed biofilm genes are decreased, confirming the role of YmdB in regulating late adaptive responses of B. subtilis.

Control of the Diadenylate Cyclase CdaS in Bacillus subtilis AN AUTOINHIBITORY DOMAIN LIMITS CYCLIC DI-AMP PRODUCTION

The Gram-positive bacterium Bacillus subtilis encodes three diadenylate cyclases that synthesize the essential signaling nucleotide cyclic di-AMP. The activities of the vegetative enzymes DisA and CdaA are controlled by protein-protein interactions with their conserved partner proteins. Here, we have analyzed the regulation of the unique sporulation-specific diadenylate cyclase CdaS. Very low expression of CdaS as the single diadenylate cyclase resulted in the appearance of spontaneous suppressor mutations. Several of these mutations in the cdaS gene affected the N-terminal domain of CdaS. The corresponding CdaS mutant proteins exhibited a significantly increased enzymatic activity. The N-terminal domain of CdaS consists of two α-helices and is attached to the C-terminal catalytically active diadenylate cyclase (DAC) domain. Deletion of the first or both helices resulted also in strongly increased activity indicating that the N-terminal domain serves to limit the enzyme activity of the DAC domain. The structure of YojJ, a protein highly similar to CdaS, indicates that the protein forms hexamers that are incompatible with enzymatic activity of the DAC domains. In contrast, the mutations and the deletions of the N-terminal domain result in conformational changes that lead to highly increased enzymatic activity. Although the full-length CdaS protein was found to form hexamers, a truncated version with a deletion of the first N-terminal helix formed dimers with high enzyme activity. To assess the role of CdaS in sporulation, we assayed the germination of wild type and cdaS mutant spores. The results indicate that cyclic di-AMP formed by CdaS is required for efficient germination

Post-transplant multimorbidity index and quality of life in patients with chronic graft-versus-host disease—results from a joint evaluation of a prospective German multicenter validation trial and a cohort from the National Institutes of Health

Comorbidity after allogeneic hematopoietic stem cell transplantation (alloHSCT) impairs quality of life (QoL), physical functioning, and survival. We developed a new standardized measure to capture comorbidity after transplantation, the Posttransplant Multimorbidity Index (PTMI) in a cohort of 50 long term survivors. We subsequently evaluated the content validity and impact on survival and QoL within a multicenter trial, including 208 patients (pts) after alloHSCT, who were prospectively evaluated applying the FACT-BMT, the Human Activity Profile (HAP), the SF-36 v.2, PTMI and the Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI). The most prevalent comorbidities were compensated arterial hypertension (28.4%), ambulatory infections (25.5%), iron overload (23%), mild renal function impairment (20%), and osteoporosis (13%). Applying the PTMI 13% of patients had no comorbidity, while 37.1% had 1–3 comorbidities, 27.4% had 4–6 comorbidities, and 13.5% had > 6 comorbidities. Chronic graft-versus-host disease (cGvHD) was significantly associated with the PTMI, while age and prior acute GvHD were not. In contrast, the HCT-CI was not associated with the presence of cGvHD. cGvHD was significantly associated with depression (r = 0.16), neurological disease (r = 0.21), osteoporosis (r = 0.18) and nonmelanoma skin cancer (r = 0.26). The PTMI demonstrated strong measurement properties and compared to the HCT-CI captured a wider range of comorbidities associated with cGvHD