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result(s) for
"O’Leary, D. Peter"
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Autophagy induced by taurolidine protects against polymicrobial sepsis by promoting both host resistance and disease tolerance
2022
Sepsis, septic shock, and their sequelae are the leading causes of death in intensive care units, with limited therapeutic options. Disease resistance and tolerance are two evolutionarily conserved yet distinct defense strategies that protect the host against microbial infection. Here, we report that taurolidine administered at 6 h before septic challenge led to strong protection against polymicrobial sepsis by promoting both host resistance and disease tolerance characterized by accelerated bacterial clearance, ameliorated organ damage, and diminished vascular and gut permeability. Notably, taurolidine administered at 6 h after septic challenge also rescued mice from sepsis-associated lethality by enhancing disease tolerance to tissue and organ injury. Importantly, this in vivo protection afforded by taurolidine depends on an intact autophagy pathway, as taurolidine protected wild-type mice but was unable to rescue autophagy-deficient mice from microbial sepsis. In vitro, taurolidine induced light chain 3-associated phagocytosis in innate phagocytes and autophagy in vascular endothelium and gut epithelium, resulting in augmented bactericidal activity and enhanced cellular tolerance to endotoxin-induced damage in these cells. These results illustrate that taurolidine-induced autophagy augments both host resistance and disease tolerance to bacterial infection, thereby conferring protection against microbial sepsis.
Journal Article
Evaluation of the Cytotoxic Effects of the Novel Antineoplastic Agent 1,4,5-Oxathiazinane-4,4-dioxide on Triple Negative Breast Cancer Cells
by
PFIRRMANN, ROLF W.
,
O’LEARY, D. PETER
,
CORRIGAN, MARK A.
in
Acetylcysteine
,
Apoptosis
,
Aqueous solutions
2021
Adjuvant therapeutic options are limited for triple negative breast cancer (TNBC). Thus, we evaluated the cytotoxic effects of the newly synthesized antineoplastic agent 1,4,5-Oxathiazinane-4,4-dioxide (OTD) on TNBC cells as a potential cancer therapeutic strategy.
TNBC primary BT-20 and metastatic MDA-MB-231 cell lines were treated with increasing concentrations of OTD for various time periods to assess cell viability. Cell necrosis, apoptosis, necroptosis, autophagy, and ROS generation were evaluated using assay kits or specific inhibitors.
Treatment with OTD resulted in a dose- and time-dependent cell death of TNBC BT-20 and MDA-MB-231 cells. OTD also dose-dependently arrested TNBC cell proliferation. Notably, treatment with OTD induced both necrosis and apoptosis of TNBC cells, while the pan-caspase inhibitor Z-VAD-FMK partially attenuated OTD-induced cell death. Importantly, abrogated OTD-induced cell death was observed in the presence of the ROS scavenger N-acetylcysteine (NAC), whereas enhanced OTD-induced cell death was observed after the addition of the glutathione synthesis inhibitor BSO, indicating OTD-induced killing of TNBC cells via a reactive oxygen species-dependent mechanism.
OTD is strongly cytotoxic to both primary and metastatic TNBC cells, possibly by inducing multiple cell death pathways.
Journal Article
Epiploic appendagitis: 7-year experience and relationship with visceral obesity
2018
PurposeLocation, size, and local inflammatory findings in primary epiploic appendagitis (EA) have not been reported outside of small studies. The association between EA and increased adiposity is controversial. The goals of this project are to compare demographics and imaging-based measurements of adiposity between patients with EA and patients with acute abdomen without EA, and to identify CT features of EA.MethodsA consecutive sample of acute, primary EA (n = 100), and control (acute abdomen; n = 100) was selected retrospectively. Cases of suspected EA were included if they had the characteristic ovoid fatty mass and hyperattenuated ring sign on CT. Abdominal adipose volume (AAV), visceral adipose area (VAA), and subcutaneous adipose area (SAA) were quantified by CT. Location, size, and frequency of coexisting local inflammatory findings in EA patients were recorded.ResultsEA had 60% greater AAV, 117% greater VAA, and 35% greater SAA than control subjects (p < 0.0001). Males composed a great proportion of the EA group (67%) than the control group (41%) (p = 0.0002). Inflamed appendage was found in sigmoid colon in 49% of cases, descending colon in 23%, and right colon in 19%. Peritoneal thickening was frequent (76%) and bowel wall thickening was common (47%). Diverticulosis coexisted incidentally in 28%.ConclusionEA is associated with increased abdominal adipose tissue. EA can occur in both sexes at any age, but occurs at age 50 on average and more frequently in males. Patient with EA exhibited central hyperdense dot (79%), peritoneal thickening (76%), and bowel wall thickening (47%).
Journal Article
Activation of Both TLR and NOD Signaling Confers Host Innate Immunity-Mediated Protection Against Microbial Infection
2019
The detection of microbial pathogens relies on the recognition of highly conserved microbial structures by the membrane sensor Toll-like receptors (TLRs) and cytosolic sensor NOD-like receptors (NLRs). Upon detection, these sensors trigger innate immune responses to eradicate the invaded microbial pathogens. However, it is unclear whether TLR and NOD signaling are both critical for innate immunity to initiate inflammatory and antimicrobial responses against microbial infection. Here we report that activation of both TLR and NOD signaling resulted in an augmented inflammatory response and the crosstalk between TLR and NOD led to an amplified downstream NF-κB activation with increased nuclear transactivation of p65 at both TNF-α and IL-6 promoters. Furthermore, co-stimulation of macrophages with TLR and NOD agonists maximized antimicrobial activity with accelerated phagosome maturation. Importantly, administration of both TLR and NOD agonists protected mice against polymicrobial sepsis-associated lethality with increased serum levels of inflammatory cytokines and accelerated clearance of bacteria from the circulation and visceral organs. These results demonstrate that activation of both TLR and NOD signaling synergizes to induce efficient inflammatory and antimicrobial responses, thus conferring protection against microbial infection.
Journal Article
RandomiSed clinical trial assessing Use of an anti-inflammatoRy aGent in attenUating peri-operatiVe inflAmmatioN in non-meTastatic colon cancer – the S.U.R.G.U.V.A.N.T. trial
by
Neary, Peter M.
,
Jinih, Marcel
,
Pfirrmann, Rolf W.
in
Aged
,
Analysis
,
Anti-inflammatory agents
2018
Background
Peri-operative inflammation has been extensively highlighted in cancer patients as detrimental. Treatment strategies to improve survival for cancer patients through targeting peri-operative inflammation have yet to be devised.
Methods
We conducted a multi-centre, randomised controlled clinical trial using Taurolidine in non-metastatic colon cancer patients. Patients were randomly assigned to receive Taurolidine or a placebo. The primary endpoint for the study was the mean difference in day 1 IL-6 levels. Secondary clinical endpoints included rates of post-operative infections and tumor recurrence.
Results
A total of 293 patients were screened for trial inclusion. Sixty patients were randomised. Twenty-eight patients were randomised to placebo and 32 patients to Taurolidine. IL-6 levels were equivalent on day 1 post-operatively in both groups. However, IL-6 levels were significantly attenuated over the 7 day study period in the Taurolidine group compared to placebo (
p
= 0.04). In addition, IL-6 levels were significantly lower at day 7 in the Taurolidine group (p = 0.04). There were 2 recurrences in the placebo group at 2 years and 1 in the Taurolidine group. The median time to recurrence was 19 months in the Placebo group and 38 months in the Taurolidine group (
p
= 0.27). Surgical site infection was reduced in the Taurolidine treated group (
p
= 0.09).
Conclusion
Peri-operative use of Taurolidine significantly attenuated circulating IL-6 levels in the initial 7 day post-operative period in a safe manner. Future studies are required to establish the impact of IL-6 attenuation on survival outcomes in colon cancer.
Trial registration
The trial was registered with EudraCT (year = 2008, registration number =
005570–12
) and ISRCTN (year = 2008, registration number =
77,829,558
).
Journal Article
TLR-4 Signalling Accelerates Colon Cancer Cell Adhesion via NF-κB Mediated Transcriptional Up-Regulation of Nox-1
by
Bhatt, Lavinia
,
Wang, Jiang H.
,
Redmond, H. Paul
in
1-Phosphatidylinositol 3-kinase
,
Adhesion
,
AKT protein
2012
Surgery induced inflammation is a potent promoter of tumour recurrence and metastasis in colorectal cancer. The recently discovered family of Nox enzymes represent a major source of endogenous reactive oxygen species (ROS) and are now heavily implicated in tumour cell metastasis. Interestingly, Nox enzymes can be 'purposefully' activated by inflammatory cytokines and growth factors which are present in abundance in the peri-operative window. As colon cancer cells express Nox enzymes and Toll-like receptor 4 (TLR-4), we hypothesised that LPS may potentiate the ability of colon cancer cells to metastasise via Nox enzyme mediated redox signalling. In support of this hypothesis, this paper demonstrates that LPS induces a significant, transient increase of endogenous ROS in SW480, SW620 and CT-26 colon cancer cells. This increase in LPS-induced ROS activity is completely abrogated by a Nox inhibitor, diphenyleneiodonium (DPI), Nox1 siRNA and an NF-κB inhibitor, Dihydrochloride. A significant increase in Nox1 and Nox2 protein expression occurs following LPS treatment. Inhibition of NF-κB also attenuates the increase of Nox1 and Nox2 protein expression. The sub-cellular location of LPS-induced ROS generation lies mainly in the endoplasmic reticulum. LPS activates the PI3K/Akt pathway via Nox generated ROS and this signal is inhibited by DPI. This LPS activated Nox mechanism facilitates a significant increase in SW480 colon cancer cell adhesion to collagen I, which is inhibited by DPI, Nox1 siRNA and a PI3K inhibitor. Altogether, these data suggest that the LPS-Nox1 redox signalling axis plays a crucial role in facilitation of colon cancer cell adhesion, thus increasing the metastatic potential of colon cancer cells. Nox1 may represent a valuable target in which to prevent colon cancer metastasis.
Journal Article
Low-Dose Abdominal CT for Diagnosing Appendicitis
by
Andrews, Emmet J
,
Lee, Kyoung Ho
,
Redmond, H. Paul
in
Appendectomy
,
Appendicitis
,
Appendicitis - diagnostic imaging
2012
To the Editor:
The study by Kim et al. (April 26 issue)
1
explores a major issue in radiology. It is well known that decreasing x-ray tube kilovoltage and current is the simplest way to reduce radiation dose. But this reduction in dose is obtained at the penalty of image noise.
2
Recent developments in equipment are helping to reduce radiation dose without decreasing image quality. When used in standard abdominal examinations, both adaptive statistical iterative reconstruction and adaptive image filtering can reduce the radiation dose a patient receives by 80%, without compromising image quality and without increasing noise.
3
The authors did . . .
Journal Article
TLR-4 Signalling Accelerates Colon Cancer Cell Adhesion via NF-kappaB Mediated Transcriptional Up-Regulation of Nox-1
by
Cotter, Thomas G
,
Bhatt, Lavinia
,
Redmond, H. Paul
in
Care and treatment
,
Colon cancer
,
Genetic aspects
2012
Surgery induced inflammation is a potent promoter of tumour recurrence and metastasis in colorectal cancer. The recently discovered family of Nox enzymes represent a major source of endogenous reactive oxygen species (ROS) and are now heavily implicated in tumour cell metastasis. Interestingly, Nox enzymes can be 'purposefully' activated by inflammatory cytokines and growth factors which are present in abundance in the peri-operative window. As colon cancer cells express Nox enzymes and Toll-like receptor 4 (TLR-4), we hypothesised that LPS may potentiate the ability of colon cancer cells to metastasise via Nox enzyme mediated redox signalling. In support of this hypothesis, this paper demonstrates that LPS induces a significant, transient increase of endogenous ROS in SW480, SW620 and CT-26 colon cancer cells. This increase in LPS-induced ROS activity is completely abrogated by a Nox inhibitor, diphenyleneiodonium (DPI), Nox1 siRNA and an NF-[kappa]B inhibitor, Dihydrochloride. A significant increase in Nox1 and Nox2 protein expression occurs following LPS treatment. Inhibition of NF-[kappa]B also attenuates the increase of Nox1 and Nox2 protein expression. The sub-cellular location of LPS-induced ROS generation lies mainly in the endoplasmic reticulum. LPS activates the PI3K/Akt pathway via Nox generated ROS and this signal is inhibited by DPI. This LPS activated Nox mechanism facilitates a significant increase in SW480 colon cancer cell adhesion to collagen I, which is inhibited by DPI, Nox1 siRNA and a PI3K inhibitor. Altogether, these data suggest that the LPS-Nox1 redox signalling axis plays a crucial role in facilitation of colon cancer cell adhesion, thus increasing the metastatic potential of colon cancer cells. Nox1 may represent a valuable target in which to prevent colon cancer metastasis.
Journal Article
Pioglitazone after Ischemic Stroke or Transient Ischemic Attack
by
Kleindorfer, Dawn
,
Inzucchi, Silvio E
,
Berger, Leo
in
Aged
,
Bone surgery
,
Brain Ischemia - drug therapy
2016
In this trial in nondiabetic patients with insulin resistance and a recent ischemic stroke or transient ischemic attack, pioglitazone was associated with a lower risk of stroke and MI than was placebo but with a higher risk of weight gain, edema, and bone fracture.
Ischemic stroke and transient ischemic attack (TIA) affect more than 14 million persons worldwide annually.
1
,
2
Affected patients are at increased risk for future cardiovascular events,
3
,
4
and prevention of these adverse outcomes is a major goal in their care.
Treatment of insulin resistance represents a potential new preventive strategy that could be added to standard care after ischemic stroke or TIA.
5
Insulin resistance is nearly universal in patients with type 2 diabetes but is also present in more than 50% of patients without diabetes who have had an ischemic stroke or a TIA.
6
The presence of insulin resistance increases . . .
Journal Article