Long Term Study of Protective Mechanisms of Human Adipose Derived Mesenchymal Stem Cells on Cisplatin Induced Kidney injury in Sprague-Daweley Rats

Background/Aims: Long-term evaluation of cisplatin induced nephrotoxicity and the probable renal protective activities of stem cells are lacking up until now. We evaluated the early and long-term role of human adipose derived mesenchymal stem cells (ADMSCs) in prevention or amelioration of cisplatin induced acute kidney injury (AKI) in Sprague-Dawley rats. For this, we determined the kidney tissue level of oxidative stress markers in conjugation with a renal histopathological scoring system of both acute and chronic renal changes. Methods: This study used eighty Sprague-Dawley (SD) rats weighing 250-300g. They were assigned into four equal groups (each group n=20): (I) Negative control group, rats injected with single dose of 1 ml normal saline. (II) Positive control cisplatin, rats injected with a single dose of 5 mg/kg I.P in 1 ml saline. (III) Cisplatin and culture media group, rats injected with 0.5 ml of culture media single dose into the tail vein and (IV) Cisplatin and ADMSCs group, rats injected with a single dose of 0.5 ml of culture media containing 5 x106ADMSCs into the tail vein one day after cisplatin administration. Each main group was further divided according to the timing of sacrifice into four subgroups (each subgroup n=5). Rats in the subgroup A were sacrificed after 4 days; subgroup B were sacrificed after 7 days; subgroup C were sacrificed after 11 days; and subgroup D were sacrificed after 30 days. Before sacrifice, 24 hrs.-urine was collected using a metabolic cage. Renal function was evaluated through blood urea nitrogen (BUN), serum creatinine and creatinine clearance. Kidney tissue homogenate oxidative stress parameters, Malondialdehyde (MDA), Superoxide dismutase (SOD) and Glutathione (GSH) were determined. In addition, histopathological analysis for active injury, regenerative and chronic changes was performed. Results: ADMSCs were characterized and their capability of differentiation was proved. Cisplatin induced a significant increase in plasma creatinine and tissue MDA and induced a decrease in SOD, GSH and creatinine clearance. ADMSCs attenuated these changes. Cisplatin resulted in prominent histopathological changes in the term of tubular necrosis, atrophy, inflammatory cells infiltration and fibrosis. ADMSCs significantly lowered the injury score at day 4, 7, 11 and 30 with marked regenerative changes starting from day 4 and limited fibrotic score at day 30. Conclusion: ADMSCs have both protective and regenerative abilities with consequent limitation of the development of renal fibrosis after the cisplatin induced acute tubular necrosis, largely through an anti-oxidative activity

Preoperative nasopharyngeal swab testing and postoperative pulmonary complications in patients undergoing elective surgery during the SARS-CoV-2 pandemic.

BACKGROUND: Surgical services are preparing to scale up in areas affected by COVID-19. This study aimed to evaluate the association between preoperative SARS-CoV-2 testing and postoperative pulmonary complications in patients undergoing elective cancer surgery. METHODS: This international cohort study included adult patients undergoing elective surgery for cancer in areas affected by SARS-CoV-2 up to 19 April 2020. Patients suspected of SARS-CoV-2 infection before operation were excluded. The primary outcome measure was postoperative pulmonary complications at 30 days after surgery. Preoperative testing strategies were adjusted for confounding using mixed-effects models. RESULTS: Of 8784 patients (432 hospitals, 53 countries), 2303 patients (26.2 per cent) underwent preoperative testing: 1458 (16.6 per cent) had a swab test, 521 (5.9 per cent) CT only, and 324 (3.7 per cent) swab and CT. Pulmonary complications occurred in 3.9 per cent, whereas SARS-CoV-2 infection was confirmed in 2.6 per cent. After risk adjustment, having at least one negative preoperative nasopharyngeal swab test (adjusted odds ratio 0.68, 95 per cent confidence interval 0.68 to 0.98; P = 0.040) was associated with a lower rate of pulmonary complications. Swab testing was beneficial before major surgery and in areas with a high 14-day SARS-CoV-2 case notification rate, but not before minor surgery or in low-risk areas. To prevent one pulmonary complication, the number needed to swab test before major or minor surgery was 18 and 48 respectively in high-risk areas, and 73 and 387 in low-risk areas. CONCLUSION: Preoperative nasopharyngeal swab testing was beneficial before major surgery and in high SARS-CoV-2 risk areas. There was no proven benefit of swab testing before minor surgery in low-risk areas