MyMedR

Displaying all 3 publications

Abstract:

Sort:

Fulltext Pathological Complete Response After Neoadjuvant Therapy in Rectal Adenocarcinoma: a 5-Year Follow-up

Leow YC, Roslani AC, Xavier RG, Lee FY

Indian J Surg, 2021 May 27.
PMID: 34075282 DOI: 10.1007/s12262-021-02945-5

Neoadjuvant therapy is the gold standard treatment of locally advanced rectal cancer. It may induce complete sterilization of tumor cell and decreases its local recurrence rate. While 15-20% of patients were found to have pathological complete response (pCR) with combined multimodal therapy, Asian data were generally scarce. pCR rate can indicate the suitability of applying the "watch-and-wait" strategy, which advocates deferment of surgery that can alleviate surgery-associated morbidity.To determine the percentage of pCR of rectal cancer after neoadjuvant therapy. Patients diagnosed with rectal cancer underwent treatment from 2013 to 2017 were retrieved retrospectively. Demographic data, tumor localization, pre- and post-operative pathological reports, neoadjuvant therapy, and pCR status were collected from patients' records. A total of 242 out of 259 patients were treated with definitive rectal surgery. Mean age was 67.1 years old. Chinese ethnicity and male gender were predominant (n = 131, 54.1% and n = 146, 64.3% respectively). More than half (n = 124, 51.2%) had tumor located at mid or low rectum. Histologically, moderate differentiated adenocarcinoma was predominant (n = 227, 93.8%). Merely half (n = 123, 50.8%) of the patients received neoadjuvant chemoradiation therapy, but only 12 (9.8%) had a pCR. From follow-up on these 12 pCR patients, most had 2-year disease-free survival but 1 (8.3%) of the pCR had distant metastasis within 1-year post-surgery. The pathological complete response rate in our center was lower than reported. Stringent patient selection with close follow-up for patients should be carried out if the "watch-and-wait" strategy is implemented in our population.
Cytoplasmic and periplasmic expression of recombinant shark VNAR antibody in Escherichia coli

Leow HC, Fischer K, Leow YC, Braet K, Cheng Q, McCarthy J

Prep Biochem Biotechnol, 2019;49(4):315-327.
PMID: 30767708 DOI: 10.1080/10826068.2019.1566145

Shark variable new antigen receptors (VNARs) are known to possess excellent heat-stability, and the long complementarity determining region 3 (CDR3) has permitted it to penetrate into the cleft region of antigens. The number of cysteine (Cys) residues contained within VNAR is greater than in conventional antibodies, entailing disulfide bond formation in both the inter- or intra-loop regions is required for interactions with the target protein antigens. Therefore, the selection of a suitable expression system is important to ensure the solubility and correct folding of functional VNAR protein production. Unlike higher organisms, the machinery for effecting posttranslational modifications of proteins in Escherichia coli (E. coli) are less sophisticated. To overcome this circumstance, a pDSB-28Y vector fusion with DsbA signal peptide was engineered for periplasmic H8VNAR production. Despite the periplasmic proteins showing a lower yield (62 µg/mL) than cytosolic proteins (468 µg/mL) that is obtained from pET-28a vector, it has demonstrated better performance than that of a cytosolic protein in terms of absorbance. However, these readings were still inferior to that of positive control mouse monoclonal antibody (mAb) C1-13 in this experiment. Therefore, further investigation is required to improve the binding affinity of selected recombinant VNAR towards malaria biomarkers.
COVID-19 pandemic and its impact on emergency surgery in colorectal cancer: A single centre experience

Ng GH, Philip Ding HL, Leow YC, Umasangar R, Ang CW

Med J Malaysia, 2023 Jan;78(1):32-34.
PMID: 36715188

INTRODUCTION: The COVID-19 pandemic has led to major changes in the provision of surgical services and also affected patients' health-seeking behaviour. This contributes to delayed presentation of many surgical conditions resulting in poorer outcomes. Colorectal cancer (CRC) patients who present with acute surgical emergencies such as complete bowel obstruction, perforation, bleeding or sepsis often require immediate intervention. This study aimed to assess the impact of COVID-19 pandemic on the proportion of emergency surgery in CRC patients.
MATERIALS AND METHODS: This is a retrospective cohort study. All CRC patients who underwent elective and emergency surgery from January until December 2019 (pre-COVID era) and September 2020 until August 2021 (COVID era) were included. Patient demographics, presentation, tumour stage, surgery performed and waiting time for surgery were collected. Data were then compared.
RESULTS: Seventy-seven and 76 new cases of CRC underwent surgery before and during COVID-19, respectively. The proportions of emergency surgery before and during COVID-19 are 29% vs 33% (p=0.562). Of those who required emergency surgery, the proportions of patients who required stoma formation are 59% vs 72% (p= 0.351). There was no difference in median waiting time for patients requiring elective surgery (p= 0.668).
CONCLUSION: The proportion of emergency surgery for CRC patients is not statistically higher during the pandemic.

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links