Development and Validation of a Scoring System to Predict Severe Acute Lower Gastrointestinal Bleeding in Vietnamese.

BACKGROUND/AIMS: The prevalence of acute lower gastrointestinal bleeding (ALGIB) has progressively increased worldwide but there are few studies in Asian populations. This study aimed to develop and validate a scoring system to predict severe ALGIB in Vietnamese. METHODS: Risk factors for severe ALGIB were identified by multiple logistic regression analysis using data from a retrospective cohort of 357 patients admitted to a tertiary hospital. These factors were weighted to develop the severe acute lower gastrointestinal bleeding (SALGIB) score to predict severe ALGIB. The performance of SALGIB was validated in a prospective cohort of 324 patients admitted to 6 other hospitals using area under the receiver operating characteristics curve (AUC) analysis. RESULTS: There were four factors at admission independently associated with severe ALGIB in the derivation cohort: heart rate ≥ 100/min, systolic blood pressure < 100 mmHg, hematocrit < 35%, and platelets ≤ 150 × 103/µL. The SALGIB score determined severe ALGIB with AUC values of 0.91 and 0.86 in the derivation and validation cohorts, respectively. A SALGIB score < 2 associated with low risk of severe ALGIB in both cohorts (3.7% and 1.2%; respectively). CONCLUSIONS: The SALGIB score has good performance in discriminating risk of severe ALGIB in Vietnamese.

Phosphonate-Functionalized Polycarbonates Synthesis through Ring-Opening Polymerization and Alternative Approaches.

Well-defined phosphonate-functionalized polycarbonate with low dispersity (Ð = 1.22) was synthesized using organocatalyzed ring-opening polymerization (ROP) of novel phosphonate-based cyclic monomers. Copolymerization was also performed to access different structures of phosphonate-containing polycarbonates (PC). Furthermore, phosphonate-functionalized PC was successfully synthesized using a combination of ROP and post-modification reaction.

A case report of Cronkhite-Canada syndrome first encounterd at a hospital in northern Vietnam.

Introduction and importance: Cronkhite-Canada syndrome (CCS) is an extremely rare non-inherited syndrome first described in 1955 with only about 500 more cases reported so far. Since the aetiology of the disease remains unknown, there were no specific treatments in consensus. In many countries, CCS is a completely new condition that may confuse physicians at first encounter. Lessons should be learned from these cases by gastrointestinal specialists to be aware of this condition in any circumstances. Case presentation: The authors reported a case study of a 45-year-old Vietnamese male with CCS diagnosis, which encountered at our centre for the first time. Clinical discussion: The definitive diagnosis was provided by combining clinical characteristics, and endoscopic and histopathologic features, after excluding other causes of gastrointestinal polyposis. The patient responds to corticosteroids, proton pump inhibitors, and nutritional support right after treatment. After 1 year of treatment, his symptoms ameliorated completely although colon polyps insignificantly reduced. Conclusion: Gastroenterologists should always be aware of patients with CCS with the following symptoms: gastrointestinal hamartomatous polyps, diarrhoea, and the dermatologic triad of alopecia, hyperpigmentation, and onychodystrophy.

Magnifying Chromoendoscopy with Flexible Spectral Imaging Color Enhancement, Indigo Carmine, and Crystal Violet in Predicting the Histopathology of Colorectal Polyps: Diagnostic Value in a Scare-Setting Resource.

Background and Aims: Virtual magnifying chromoendoscopy with flexible spectral imaging color enhancement (FICE), image-enhanced endoscopy techniques, and dye-staining magnifying chromoendoscopy (with Indigo carmine and Crystal violet) have contributed to better visualization of the pit pattern and vascular structure of colorectal polyp. Therefore, magnifying chromoendoscopy is capable of predicting the histopathological results of colorectal polyp without biopsy and remains their diagnostic values over time, especially in scare-setting resources. This study compared the images of magnifying chromoendoscopy between FICE, Indigo carmine, and Crystal violet and then assessed their diagnostic values based on colorectal polyps' histopathology as a gold standard. Methods: A total of 332 polyps of 266 patients were endoscopically evaluated from June 2016 to September 2019. After identified by white light endoscopy, polyps continued to be evaluated by virtual magnifying chromoendoscopy (×50-150 times) with FICE. The capillary-vessel pattern was divided into 5 subtypes according to the number, morphology, and distribution of the fine blood vessels according to Teixeira classification. Next, they were stained with Indigo carmine 0.2% and then Crystal violet 0.05% and were classified according to Kudo's pit pattern classification. Finally, polyps were resected by endoscopy or surgery and biopsy and compared with histopathological results of either neoplastic or nonplastic polyp. Results: The number of neoplastic polyps was 278/332 with 231 adenoma polyps and 47 carcinoma polyps. Magnifying chromoendoscopy has high sensitivity and accuracy when compared with the histopathological results of colorectal polyps. The sensitivity, specificity, and accuracy of magnifying chromoendoscopy with Crystal violet are 97.2%, 72.2%, and 93.0%; with Indigo carmine are 96.0%, 72.2%, and 92.1%; and with FICE are 92.1%, 68.5%, and 88.3%. Conclusions: Among the three methods, Crystal violet has the highest sensitivity and accuracy in predicting histopathological results of colorectal polyps. FICE has shown its diagnostic value with reliable sensitivity and accuracy and should still be a reasonable endoscopic choice for physicians in scare-setting resources regardless its moderate specificity. Physicians should base on their facility and capability to determine an appropriate endoscopy technique.

Recurrent PROC and novel PROS1 mutations in Vietnamese patients diagnosed with idiopathic deep venous thrombosis.

INTRODUCTION: Genetic mutations of PROC and PROS1 are well-known risk factors for deep venous thrombosis (DVT) in the Asian population. However, the genetic profile of Vietnamese patients with DVT remains elusive. This study aimed to investigate the spectrum of genetic mutations of these two genes in Vietnamese patients diagnosed with idiopathic DVT. MATERIALS AND METHODS: A total of 50 Vietnamese patients diagnosed with idiopathic DVT were recruited in this study. The entire coding regions of the protein C and protein S genes were amplified and directly sequenced to determine genetic alterations. RESULTS: Four and six genetic mutations were detected in protein C and protein S genes, respectively, in 24 Vietnamese DVT patients. PROC c.565C > T (p.R189W) was the most common mutation found in 13 out of 50 patients, while the mutations of PROS1 comprised three missense and three nonsense variants which diffuse along the gene. CONCLUSIONS: This study shows that mutations of protein C and protein S genes are prevalent in Vietnamese patients diagnosed with idiopathic DVT, and PROC c.565C > T (p.R189W) was the most common genetic alteration.

An External Validation Study of the Oakland and Glasgow-Blatchford Scores for Predicting Adverse Outcomes of Acute Lower Gastrointestinal Bleeding in an Asian Population.

AIMS: This study is aimed at (1) validating the performance of Oakland and Glasgow-Blatchford (GBS) scores and (2) comparing these scores with the SALGIB score in predicting adverse outcomes of acute lower gastrointestinal bleeding (ALGIB) in a Vietnamese population. METHODS: A multicenter cohort study was conducted on ALGIB patients admitted to seven hospitals across Vietnam. The adverse outcomes of ALGIB consisted of blood transfusion; endoscopic, radiologic, or surgical interventions; severe bleeding; and in-hospital death. The Oakland and GBS scores were calculated, and their performance was compared with that of SALGIB, a locally developed prediction score for adverse outcomes of ALGIB in Vietnamese, based on the data at admission. The accuracy of these scores was measured using the area under the receiver operating characteristic curve (AUC) and compared by the chi-squared test. RESULTS: There were 414 patients with a median age of 60 (48-71). The rates of blood transfusion, hemostatic intervention, severe bleeding, and in-hospital death were 26.8%, 15.2%, 16.4, and 1.4%, respectively. The SALGIB score had comparable performance with the Oakland score (AUC: 0.81 and 0.81, respectively; p = 0.631) and outperformed the GBS score (AUC: 0.81 and 0.76, respectively; p = 0.002) for predicting the presence of any adverse outcomes of ALGIB. All of the three scores had acceptable and comparable performance for in-hospital death but poor performance for hemostatic intervention. The Oakland score had the best performance for predicting severe bleeding. CONCLUSIONS: The Oakland and SALGIB scores had excellent and comparable performance and outperformed the GBS score for predicting adverse outcomes of ALGIB in Vietnamese.

A novel 3-hydroxypropionic acid-inducible promoter regulated by the LysR-type transcriptional activator protein MmsR of Pseudomonas denitrificans.

MmsR (33.3 kDa) is a putative LysR-type transcriptional activator of Pseudomonas denitrificans. With the help of 3-hydroxypropionic acid (3-HP), an important platform chemical, MmsR positively regulates the expression of mmsA, which encodes methylmalonylsemialdehyde dehydrogenase, the enzyme involved in valine degradation. In the present study, the cellular function of MmsR and its binding to the regulatory DNA sequence of mmsA expression were investigated both in vivo and in vitro. Transcription of the mmsA was enhanced >140-fold in the presence of 3-HP. In the MmsR-responsive promoter region, two operators showing dyad symmetry, designated O1 and O2 and centered at the -79 and -28 positions, respectively, were present upstream of the mmsA transcription start site. An electrophoretic mobility shift assay indicated that MmsR binds to both operator sites for transcription activation, probably in cooperative manner. When either O1 or O2 or both regions were mutated, the inducibility by the MmsR-3-HP complex was significantly reduced or completely removed, indicating that both sites are required for transcription activation. A 3-HP sensor was developed by connecting the activation of MmsR to a green fluorescent readout. A more than 50-fold induction by 25 mM 3-HP was observed.