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- Baban, Bayar, 1973-
(författare)
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Colorectal cancer and surgery : Insights into insulin resistance and inflammatory markers
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The art of surgery has progressively extended from the realm of anatomy to encompass physiology and beyond, in search of further refinement and optimal recovery. Integral to this is a deeper understanding of the body’s essential metabolic and inflammatory responses to surgical trauma.This thesis aims to provide insights into the intricate interplay between insulin resistance, inflammation and surgical interventions in colorectal cancer patients, as each has an influence on postoperative recovery. Particular emphasis is placed on the role of inflammasomes – central mediators of the innate immune response, adept at detecting and responding to a diverse range of triggers, yet insufficiently explored in these specific contexts.Study I is a comparative analysis of the hyperinsulinemic–euglycaemic clamp and homeostatic model assessment (HOMA) in determining postoperative insulin resistance in 113 patients undergoing various elective surgeries. The findings establish the clamp as the accurate method, detecting key physiological distinctions missed by HOMA.Study II, an exploratory case–control study, assesses insulin sensitivity and inflammatory markers in 20 colorectal cancer patients compared to 10 matched healthy controls. Results indicate insulin resistance, reduced inflammasome activity in circulating immune cells and elevated systemic IL-1β and IL-6 levels in patients.Study III, a pilot exploratory study of 17 patients from Study II, assesses the impact of surgical technique, open versus minimally invasive surgery, on postoperative insulin resistance and inflammation in colorectal cancer resections. It indicates a differential inflammatory response with higher levels in open surgeries, yet a consistent degree of insulin resistance across both surgical techniques.Study IV explores the perioperative temporal sequencing of inflammation and inflammasome action in 18 patients from Study II undergoing elective colorectal cancer resections. It points to a more immediate and pronounced inflammatory response in open surgery compared to minimally invasive surgery, though both techniques show reduced intraoperative caspase-1 activity.In conclusion, the hyperinsulinemic euglycaemic clamp is the accurate method in determinations of postoperative insulin resistance. Patients with colorectal cancer, in comparison to matched healthy controls, exhibit insulin resistance and higher levels of inflammation, but decreased inflammasome (caspase-1) activity in circulating immune cells. Finally, colorectal cancer resections induce both insulin resistance and inflammation; however, the surgical technique utilized only significantly affects the latter, with generally higher inflammatory / inflammasome responses in open surgery.
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| 2. |
- Huang, Chenxi, et al.
(författare)
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Exploring postoperative cognitive dysfunction and delirium in noncardiac surgery using MRI : A systematic review
- 2018
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Ingår i: Neural Plasticity. - 2090-5904. ; 2018, s. 1-12
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Forskningsöversikt (refereegranskat)abstract
- Surgical patients are at high risk of developing postoperative cognitive dysfunction (POCD) and postoperative delirium (POD). POCD and POD are associated with increased morbidity and mortality and worsening functional outcomes leading to severe socioeconomic consequences for the patient and the society in general. Magnetic resonance imaging (MRI) offers a unique opportunity to study the anatomy and function of the brain. MRI thus plays an important role in elucidating the neuronal component of POCD and POD. Our aim has been to systematically gather MRI findings that are related to POCD and POD. Systematic searches were conducted in PubMed, EMBASE, and PsycINFO: MRI studies investigating patients with POCD as identified by perioperative cognitive testing or patients with delirium identified postoperatively by the Confusion Assessment Method. A total of ten eligible papers were included with a total of 269 surgical patients, 36 patient controls, and 55 healthy controls who all underwent MRI examination. These studies suggested that reduction of thalamic and hippocampal volumes and reduction of cerebral blood flow may be associated with POCD, while presurgery/preexisting and postoperative white matter pathology may be associated with POD. However, the evidence from these studies is rather weak. Future MRI studies are warranted to verify the current findings.
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| 3. |
- Osterman, Erik, 1991-
(författare)
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Colon Cancer, Prognosis After Surgery : What Are the Risks of Recurrent Disease, and How Do We Find Those at Risk?
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Colon cancer is the fourth most common cancer worldwide with approximately 1.2 million yearly cases. Developments in the standard of care have improved prognosis. In Paper I the recurrence risk was investigated in a national material consisting of 14,325 colon cancer patients. Three fourths of stage II patients have a risk of approximately 11%, indicating that adjuvant chemotherapy can marginally improve prognosis. In stage III, one fifth of the patients have such a low risk of recurrence that the addition of a second chemotherapeutic drug, oxaliplatin with its risk for late toxicity, may be questioned. In Paper II emerging risk factors were investigated in a thoroughly staged and described material of 416 colon cancer patients from one county. All emerging risk factors correlated with an increased recurrence risk. Adjusting for established risk factors, pN-substage and postoperative carcinoembryonic antigen (CEA) correlated independently with recurrence. Paper III investigated the completeness and correctness of recurrences in the Swedish Colorectal Cancer registry in 2,893 patients from two counties. In patients operated more than 5 years ago 2% of recurrences were not registered. In Paper IV a nomogram for clinicians was developed using registry data to aid the interpretation of the recurrence risk and discussion with patients about treatment choices. It was validated in Norwegian cancer registry data and performed better than other available nomograms.Future investigations of the cohort from paper II are planned with immunohistochemistry, tumour-normal tissue sequencing and biomarkers.In summary, recurrence rates have decreased since the early 2000s and a large proportion of patients can probably be spared some or all adjuvant treatment. Established risk factors describe a large part of the risk, but there is room for improvement. The biomarker CEA taken after surgery could aid in the selection of patients to receive adjuvant treatment and guide follow-up. Adding other biomarkers might further improve the prediction of recurrence risk, though larger, prospective patient materials are needed.
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| 4. |
- Spliid, Charlotte B., et al.
(författare)
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The specificity of the malarial VAR2CSA protein for chondroitin sulfate depends on 4-O-sulfation and ligand accessibility
- 2021
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Ingår i: Journal of Biological Chemistry. - : Elsevier BV. - 0021-9258 .- 1083-351X. ; 297:6
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Tidskriftsartikel (refereegranskat)abstract
- Placental malaria infection is mediated by the binding of the malarial VAR2CSA protein to the placental glycosaminoglycan, chondroitin sulfate. Recombinant subfragments of VAR2CSA (rVAR2) have also been shown to bind specifically and with high affinity to cancer cells and tissues, suggesting the presence of a shared type of oncofetal chondroitin sulfate (ofCS) in the placenta and in tumors. However, the exact structure of ofCS and what determines the selective tropism of VAR2CSA remains poorly understood. In this study, ofCS was purified by affinity chromatography using rVAR2 and subjected to detailed structural analysis. We found high levels of N-acetylgalactosamine 4-O-sulfation (∼80-85%) in placenta- and tumor-derived ofCS. This level of 4-O-sulfation was also found in other tissues that do not support parasite sequestration, suggesting that VAR2CSA tropism is not exclusively determined by placenta- and tumor-specific sulfation. Here, we show that both placenta and tumors contain significantly more chondroitin sulfate moieties of higher molecular weight than other tissues. In line with this, CHPF and CHPF2, which encode proteins required for chondroitin polymerization, are significantly upregulated in most cancer types. CRISPR/Cas9 targeting of CHPF and CHPF2 in tumor cells reduced the average molecular weight of cell-surface chondroitin sulfate and resulted in a marked reduction of rVAR2 binding. Finally, utilizing a cell-based glycocalyx model, we showed that rVAR2 binding correlates with the length of the chondroitin sulfate chains in the cellular glycocalyx. These data demonstrate that the total amount and cellular accessibility of chondroitin sulfate chains impact rVAR2 binding and thus malaria infection.
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