Non-sterile corn steep liquor a novel, cost effective and powerful culture media for Sporosarcina pasteurii cultivation for sand improvement

AIMS

Microbial induced calcium carbonate precipitation (MICP) is one of the bio-cementation methods for improving granular soils. This study evaluate the feasibility of obtaining a bacterial solution with high optical density and urease activity by an inexpensive corn steep liquor (CSL) medium in non-sterile conditions in order to achieve sand improvement.

METHODS AND RESULTS

Corn steep liquor media with different concentrations (different dilution rates) were prepared and, without any autoclaving (non-sterile conditions), different percentage of the inoculum solutions were added to them and incubated. Effect of inoculum solution percentage and CSL dilution rates on specifications of bacterial solution was evaluated. Urease activity and scanning electron microscope (SEM) and X-Ray Diffraction (XRD) were used to efficiency of CLS media in sand improvement. The considerable urease activity was measured as 5·7 mS cm^-1  min^-1 using nonsterile CLS. By using CYNU (CSL-Yeast extract-NH4Cl-Urea) bacterial solution, the urease activity of 5·5 mS cm^-1  min^-1 for the OD₆₀₀ (optical density at 600 nm) of 1·88 and, consequently, specific urease activity of 2·93 mS cm^-1  min^-1  OD₆₀₀ ^-1 was obtained. The highest unconfined compressive strength (811 kPa) was obtained for the CYNU. XRD revealed new calcite peaks next to the quartz peaks.

CONCLUSIONS

Production of inexpensive bacterial solution using diluted CSL as the inexpensive, effective and powerful culture media for Sporosarcina pasteurii cultivation in nonsterile conditions, allows geotechnical and biotechnological engineers to use MICP technology more widely in land improvement and field-scale bio-cementation and bioremediation projects.

SIGNIFICANCE AND IMPACT OF THE STUDY

Obtaining high urease activity of inexpensive microbial solution using diluted CSL as the culture medium in nonsterile conditions, as the unique results of this study, can be significant in the field of bioremediation studies using MICP.

Performance evaluation of a North American center using the established global benchmark for laparoscopic liver resections: A retrospective study

BACKGROUND

The global benchmark cut-offs were set for laparoscopic liver resection procedures: left lateral sectionectomy, left hepatectomy, and right hepatectomy. We aimed to compare the performance of our North American center with the established global benchmarks.

METHODS

This is a single-center study of adults who underwent laparoscopic liver resection between 2010 to 2022 at the Toronto General Hospital. Fourteen benchmarking outcomes were assessed: operation time, intraoperative blood transfusion, estimated blood loss, blood loss ≥500 mL, blood loss ≥1000mL, open-conversion, postoperative length of stay, return to operation, postoperative morbidity, postoperative major-morbidity, 30-day mortality, 90-day mortality, R1 resection, and failure to rescue. Low-risk benchmark cases were defined as follows: patients aged 18 to 70 years, American Society of Anesthesiologist score ≤ 2, tumor size <10 cm, and Child-Pugh score ≤A. Cases involving bilio-enteric anastomosis, hilar dissection, or concomitant major procedures were excluded from the low-risk category. Cases that did not meet the criteria for low-risk selection were considered high-risk cases.

RESULTS

A total of 178 laparoscopic liver resection cases were analyzed (109 left lateral sectionectomies, 45 left hepatectomies, 24 right hepatectomies). Forty-four (25%) cases qualified as low-risk cases (23 left lateral sectionectomies, 16 left hepatectomies, 5 right hepatectomies). The postoperative major morbidity and 90-day mortality after left lateral sectionectomy, left hepatectomy, and right hepatectomy for the low-risk cases were 0%, 0%, and 0%, and 0%, 0%, and 0%, respectively. For the high-risk cases post-2017, the outcomes in the same order were 0%, 0%, and 12%; 0%, 0%, and 0%, respectively. For the high-risk cases operated pre2017, the outcomes in the same order were 9%∗, 16%∗, and 18%; 2%∗, 0%, and 9%∗ (asterisks indicate not meeting the global cut-off), respectively.

CONCLUSION

A North American center was able to achieve outcomes comparable to the established global benchmark for laparoscopic liver resection.

The Terry Fox Research Institute Marathon of Hope Cancer Centres Network: A pan-Canadian precision oncology initiative

The Marathon of Hope Cancer Centres Network (MOHCCN), led by the Terry Fox Research Institute and the Terry Fox Foundation, unites researchers, clinicians, patients, funders, and other partners across Canada to accelerate precision oncology, promote collaboration and data sharing, and ultimately improve patient outcomes. This overview outlines the Network's goals, history, and challenges and opportunities. We also highlight progress toward the "MOHCCN Gold Cohort," a shared resource of clinical and genomic data from 15,000 patients.

Impact of intraoperative hypotension during laparoscopic liver resection on postoperative complications including acute kidney injury

BACKGROUND

Postoperative acute kidney injury is associated with an increase in hospital length of stay and mortality. Intraoperative hemodynamics and fluid management may contribute to acute kidney injury. The aim of this study is to evaluate the association between intraoperative duration of hypotension with adverse events after laparoscopic liver resection.

METHODS

A prospective cohort including adult patients undergoing laparoscopic liver resection between January 2010 and June 2022. Cumulative time below mean arterial blood pressure thresholds and association with major adverse events composing of postoperative acute kidney injury (≤2 days) and complications (Dindo-Clavien ≥3a) ≤30 days were assessed.

RESULTS

In 360 patients, the median age was 61 years, 206 (57%) were male, median body mass index was 26.3, and 129 (36%) patients had hepatocellular carcinoma. Acute kidney injury was recorded in 3 (0.8%) patients as stage 1, 6 (1.7%) patients as stage 2, and 7 (1.9%) patients as stage 3. Major adverse events occurred in 31 (8.6%) patients, and the median estimated blood loss was 200 mL. On continuous analysis, a threshold <60 mmHg at ≥15 minutes was found for major adverse events. The mean arterial blood pressure <55 mmHg for ≥20 minutes was associated with an increased risk of major adverse events (odds ratio 7.72; P < .001). In patients with >15 minutes of mean arterial blood pressure <60 mmHg, higher intravenous volume was associated with increase in major adverse events (P = .045), whereas adjusted intravenous volume was not associated with major adverse events (P = .657), acute kidney injury (P = .681), or blood loss (P = .875).

CONCLUSIONS

Laparoscopic liver resection is a safe procedure with a low risk of acute kidney injury. After ≥15 minutes at mean arterial blood pressure <60 mmHg, the risk of major adverse events increases. Greater intravenous fluid infusion volume was associated with an observed risk for major adverse events, suggesting that mean arterial blood pressure should be managed by vasoactive agents.