Yongyut Sirivatanauksorn - Academia.edu (original) (raw)

Papers by Yongyut Sirivatanauksorn

Frontiers in Plant Science

Pyranonaphthoquinones (PNQs) are important structural scaffolds found in numerous natural product... more Pyranonaphthoquinones (PNQs) are important structural scaffolds found in numerous natural products. Research interest in these specialized metabolites lies in their natural occurrence and therapeutic activities. Nonetheless, research progress has thus far been hindered by the lack of analytical standards and analytical methods for both qualitative and quantitative analysis. We report here that various parts of Ventilago harmandiana are rich sources of PNQs. We developed an ultraperformance liquid chromatography–electrospray ionization multiple reaction monitoring/mass spectrometry method to quantitatively determine six PNQs from leaves, root, bark, wood, and heartwood. The addition of standards in combination with a stable isotope of salicylic acid-D6 was used to overcome the matrix effect with average recovery of 82% ± 1% (n = 15). The highest concentration of the total PNQs was found in the root (11,902 μg/g dry weight), whereas the lowest concentration was found in the leaves (28...

Nature Biomedical Engineering

2 ✉ and Chayasith Uttamapinant 1 ✉ Nucleic acid detection by isothermal amplification and the col... more 2 ✉ and Chayasith Uttamapinant 1 ✉ Nucleic acid detection by isothermal amplification and the collateral cleavage of reporter molecules by CRISPR-associated enzymes is a promising alternative to quantitative PCR. Here, we report the clinical validation of the specific high-sensitivity enzymatic reporter unlocking (SHERLOCK) assay using the enzyme Cas13a from Leptotrichia wadei for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-the virus that causes coronavirus disease 2019 (COVID-19)-in 154 nasopharyngeal and throat swab samples collected at Siriraj Hospital, Thailand. Within a detection limit of 42 RNA copies per reaction, SHERLOCK was 100% specific and 100% sensitive with a fluorescence readout, and 100% specific and 97% sensitive with a lateral-flow readout. For the full range of viral load in the clinical samples, the fluorescence readout was 100% specific and 96% sensitive. For 380 SARS-CoV-2-negative pre-operative samples from patients undergoing surgery, SHERLOCK was in 100% agreement with quantitative PCR with reverse transcription. The assay, which we show is amenable to multiplexed detection in a single lateral-flow strip incorporating an internal control for ribonuclease contamination, should facilitate SARS-CoV-2 detection in settings with limited resources.

Siriraj Medical Journal

Objective: Although still uncommon, choledochal cysts (CCs) are more frequently found in Asians t... more Objective: Although still uncommon, choledochal cysts (CCs) are more frequently found in Asians than Caucasians. The incidence of malignancy associated with these cysts and the surgical outcomes have not been reported in Thailand. Methods: A retrospective review was performed of 48 adult CC patients who underwent surgery January 2005-December 2015. Their clinical data and outcomes were analyzed. Results: There were 31 (64.6%) female patients, with a female-to-male ratio of 1.8:1. The mean age ± SD at diagnosis was 40.5 ± 17.4 years. Using the modified Todani classification, 32 patients (66.7%) had a type I CC, one (2.1%) had type II, twelve (25.0%) had type IV, and three (6.3%) had type V. Twelve patients (25%) had a malignant tumor: eleven had synchronous cancer at surgery, while one with CC type I developed metachronous intrahepatic cholangiocarcinoma during the follow-up. The cholangiocarcinoma was inside the CC in 6 cases, intrahepatic in three, perihilar in two, and distal in one. The 5-year overall survival of the cohort was 68%. The factor affecting the overall survival was the coexisting cancer (p < 0.001). The 1-year and 5-year overall survival rates were 58.3% and 20%, respectively, for patients with cancer, but 96.7% and 88.4% for patients without cancer. Conclusion: The adult choledochal cysts had a high incidence of associated malignancy. Factors predicting coexisting malignancy were an age above 40 years and a significant weight loss. If cancer occurred, the overall survival was significantly poor. Even after definitive surgery, patients still need lifelong surveillance for cancer.

American Journal of Gastroenterology

Molecular cancer, Jan 18, 2018

Cholangiocarcinoma (CCA) has an abundance of tumor stroma which plays an important role in cancer... more Cholangiocarcinoma (CCA) has an abundance of tumor stroma which plays an important role in cancer progression via tumor-promoting signals. This study aims to explore the microRNA (miRNA) profile of CCA-associated fibroblasts (CCFs) and the roles of any identified miRNAs in CCA progression. miRNA expression profiles of CCFs and normal skin fibroblasts were compared by microarray. Identified downregulated miRNAs and their target genes were confirmed by real-time PCR. Their binding was confirmed by a luciferase reporter assay. The effects of conditioned-media (CM) of miRNA mimic- and antagonist-transfected CCFs were tested in CCA migration in wound healing assays. Finally, the levels of miRNA and their target genes were examined by real-time PCR and immunohistochemistry in clinical CCA samples. miR-15a was identified as a downregulated miRNA in CCFs. Moreover, PAI-2 was identified as a novel target gene of miR-15a. Recombinant PAI-2 promoted migration of CCA cells. Moreover, CM from mi...

In British Journal of Surgery, 2001

Journal of the Medical Association of Thailand = Chotmaihet thangphaet, 2013

The model for end-stage liver disease (MELD) score was used to prioritize liver allocation in the... more The model for end-stage liver disease (MELD) score was used to prioritize liver allocation in the USA that decreased the mortality in awaiting patients. The current national policy for liver allocation in Thailand is to offer organs to the transplant center, not directly to the patients themselves. The aim of the present study was to determine the accuracy of MELD score to predict the mortality of patients on liver transplantation waiting list in Thailand, a country with low organ donation. Between January 2006 and March 2007, we prospectively collected data of all patients on liver transplantation waiting list. MELD score was calculated. All patients were followed until they were transplanted, dead, or to the end of the present study. Patients were then divided into three groups (dead, alive, and transplanted) according to the outcome. Differences between groups were compared using Chi-square test. Seventy-three patients were enrolled (male:female = 48:25). Mean age was 55.6 years....

Transplantation proceedings, 2008

Organ preservation is one of the important steps that predicts the patient outcome. However, afte... more Organ preservation is one of the important steps that predicts the patient outcome. However, after revascularization, the high concentration of potassium that influxes into the circulation might cause immediate postreperfusion hyperkalemia. To prevent this complication, the portal vein has been washed out with flush fluid to remove preservation fluid before reperfusion. Up to now, it has not been established what exact amount volume of albumin provides washout of the UW solution. Eleven of 20 patients who underwent orthotopic liver transplantation (OLT) between December, 2003, and June, 2005, were enrolled in this study. OLT was performed following the standard technique. Five percent albumin (1000 mL) was flushed through the portal vein canula before reperfusion of the donor liver. Every 100 mL of flush fluid effluent was collected from an incomplete infrahepatic inferior vena cava anastomosis for electrolyte measurement. The 10 flushed fluid samples were measured for potassium con...

HPB surgery : a world journal of hepatic, pancreatic and biliary surgery, 1996

The role of intraoperative ultrasonography (IOU) in the surgical treatment of hilar cholangiocarc... more The role of intraoperative ultrasonography (IOU) in the surgical treatment of hilar cholangiocarcinoma was explored in twenty-two patients, 17 males and 5 females. The mean age was 55 years (range 36-78 years). Preoperative imaging studies included abdominal ultra-sonography and/or CT scan, and visceral angiography. Operations performed were segment III bypass in 18 patients, local resection of tumour in 2 and resection of tumour en bloc with left hepatectomy in 2. Interpretation of IOU in terms of vascular involvement by the tumour (as compared to angiography or operative findings) was correct in 21 patients; no vascular invasion in 20 and portal vein invasion in the remainder. One false negative result occurred in a patient whose IOU failed to show right hepatic artery encasement by the tumour. When compared to postoperative cholangiography or surgical specimen, IOU correctly demonstrated location and extent of the tumours in all but one patient who had incomplete tumour resection...

Journal of Surgical Oncology, 2012

Sprouty (Spry) proteins are important modulators of the RTK/Ras/MAPK pathway, overactivation of w... more Sprouty (Spry) proteins are important modulators of the RTK/Ras/MAPK pathway, overactivation of which is associated with hepatocellular carcinoma (HCC). Thus far, the roles of Sprouty in HCC is still unclear. The expressions of SPRY1, SPRY2, SPRY3, and SPRY4, at the mRNA levels were determined by quantitative RT-PCR in paired HCC and non-tumor liver tissues from 31 patients. The expression levels of SPRY1, SPRY2, and SPRY4 in tumor tissues were significantly different from those in non-tumor tissues with the average log fold change values of 0.15, -0.34, and -0.37, respectively; however, that of SPRY3 was not significantly different. SPRY1 expression was also found to be significantly up-regulated in the cases without underlying cirrhosis compared with those with cirrhosis (log fold change of 0.35 and -0.02, respectively, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05), whereas SPRY2 expression was significantly lower in the cases with advanced HCC (log fold change of -0.12 and -0.52 in early and advanced stages, respectively, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) and in those with angiolymphatic invasion (log fold change of -0.47 and -0.16 in the presence and absence thereof, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). This study demonstrates that Sprouty genes are differentially expressed in HCC and might provide some insight into their roles in HCC carcinogenesis.

The Journal of Pathology, 1999

Tissue microdissection is potentially one of the most useful techniques in molecular pathology. L... more Tissue microdissection is potentially one of the most useful techniques in molecular pathology. Laser-assisted microdissection has been developed to procure precisely the cells of interest in a tissue specimen, in a rapid and practical manner. Together with multiplex molecular approaches, it is now feasible to study genetic alterations and isolate genes and proteins in defined cell populations from complex normal and diseased tissues. The fundamental advantage of this technique is the possibility of capturing single cells from which high-quality DNA and mRNA can be isolated for analysis of sequence and quantitation of expression. Moreover, the integration of laser-assisted microdissection and proteomic analysis could identify novel protein markers for disease. The advent of laser-assisted microdissection is likely to have a profound impact on molecular pathology.

The European Journal of Surgery, 2001

To examine the capacity of oestrogen, or progesterone, or both to elicit the release of nitric ox... more To examine the capacity of oestrogen, or progesterone, or both to elicit the release of nitric oxide (NO) from T47D breast cancer cells in vitro. Prospective, longitudinal, controlled in vitro experiment. University Medical School, United Kingdom. MATERIAL AND INTERVENTIONS: T47D breast cancer cells were stimulated by micromolar to picomolar doses of 17beta-oestradiol, or progesterone, or both, with or without inhibition of NO or tamoxifen at 24 and 48 hours. Concentration of NO metabolites (nitrite + nitrate) in the culture medium measured by chemiluminescence. Both hormones dose-dependently increased the proliferation of T47D without toxic effects over the range 10(-12)-10(-6) M. Both stimulated NO production at 24 hours, micomolar doses producing a pronounced (2-4 fold) increase in the concentration of NO metabolites in culture medium (p = 0.002 and p < 0.001 for oestradiol and progesterone, respectively). By contrast, incubation with hormones for 48 hours had little effect on the concentrations of NO metabolites. NO production induced by hormones was completely inhibited by the NO synthesis inhibitor N(G)-monomethyl-L-arginine (10(-5)-10(-3) M) and by tamoxifen (10(-8)-10(-4) M) (p < 0.001 in each case). Oestrogen and progesterone have a role in stimulating NO production in T47D breast cancer cells. Inhibition of NO synthesis might be a novel therapeutic approach for reducing hormone-associated angiogenesis in breast cancer.

The Journal of …, 1999

Hepatocellular carcinomas (HCC) often contain subpopulations of cells showing heterogeneous diffe... more Hepatocellular carcinomas (HCC) often contain subpopulations of cells showing heterogeneous differentiation within each tumour. The majority of HCCs first appear as well-differentiated lesions and proliferate with gradual dedifferentiation. The present study was designed to investigate the clonal diversity which is seen with progression in neoplasms. The degree of genomic heterogeneity of HCC nodules was assessed using the arbitrarily primed-polymerase chain reaction technique. Two or more sectors of 31 HCC nodules were needle-microdissected and amplified with two different arbitrary primers in appropriate conditions. In every HCC less than 6 mm in diameter (n=18, range 3-6 mm, mean diameter 4.7 mm), all sectors of each of these lesions had the same DNA fingerprint. All HCC nodules greater than 6 mm diameter (n=13, range 7-30 mm, mean diameter 15.4 mm) showed distinct DNA fingerprints in each sector sampled (p< 0. 05, compared with size less than 6 mm in diameter). When synchronous HCCs were present, no two tumour nodules had the same DNA fingerprint. These results suggest that a process of clonal evolution occurs in expanding HCC, with neoplasms more than 6 mm in diameter developing as multiple clones. The advent of laser capture microdissection technology makes such analysis much more rapid and easily applied. Studies of clonality in HCCs, including borderline cases, are made possible by the combination of these novel techniques.