Application of gold nanoparticles-based lateral flow strip for dengue virus detection based on strand-displacement amplification / 浙江大学学报·医学版

OBJECTIVE@#To investigate the rapid and accurate method for the detection of dengue virus (DENV) by using nicking enzyme assisted strand-displacement amplification (SDA) combined with gold nanoparticles-based lateral flow strip.@*METHODS@#Total RNA of the virus was extracted by using magnetic beads method and transcribed to cDNA for SDA detection system. Nicking enzyme-assisted method was used for detecting DENV, and agarose gel electrophoresis was used for analyzing the sensitivity of SDA amplification products. A gold nanoparticles-based lateral flow strip was developed based on the principle of nucleic acid base complementary pairing to design the test line and control line. The gold particles were prepared by using sodium citrate reduction method for gold nanoparticles-based lateral flow strip construction.@*RESULTS@#The sensitivity of the SDA method was 10 fmol/L, and the sensitivity of gold nanoparticles-based lateral flow strip based on SDA method was also 10 fmol/L. In a linear range from 10 fmol/L to 10 fmol/L, the corresponding linear correlation coefficient () of DENV was 0.98. The specificity of nanoparticles-based lateral flow strip based on SDA for DENV detection was high, which was no crossing with other control groups.@*CONCLUSIONS@#A gold nanoparticles-based lateral flow strip based on SDA method for DENV detection has been established, which is convenient, fast, and the result is visible to naked eyes.

Prognostic scoring indicator in evaluation of clinical outcome in intestinal perforations.

INTRODUCTION: Acute generalised peritonitis coming forth due to underlying intestinal perforation is a critical & life-threatening medical condition. It is a common surgical emergency most of the times across the world. Misleading data on crude morbidity and mortality due to the condition usually contaminates substantially the very purpose of medical audit. Thus, early prognostic evaluation is not only desirable but mandate to much extent. High-risk patients require timely & aggressive treatment especially in severe peritonitis & to select them reasonably well, evaluation through prognostic scoring is an approach of choice. Well sought after & reasonably reliable APACHE II scoring system is used for the purpose & scores are correlated well to accentuate & measure the various factors needed for better management of condition. MATERIAL AND METHODS: The study was conducted over the period of 18 months (Jan 2010 to June 2011) on 50 patients with confirmed diagnosis of intestinal perforation. APACHE II score was calculated and correlated with their symptoms & clinical outcomes regarding morbidity and mortality. RESULTS: APACHE II score correlated well with the outcome of the study, showing score affects of two major aspects in the treatment outcome & management.1.) APACHE II score of less than 10 included 30 low risk group patients discharged in a satisfactory gratifying manner. Three out of four in high risk group with APACHE II score >20, shown adverse outcomes. 2.)Mean ICU stay of 9.75 days was found in patients with APACHE II score 20 or more compared to those with mean ICU stay of 0.13 days in patients with APACHE II score 10 or less. CONCLUSION: Acute generalized peritonitis being life-threatening medical emergency requires careful consideration in its management that needs to be economically viable, acceptably feasible and outcome oriented with better allocation & utilization of ICU resources that needs meticulous case analysis & prioritization. This present study helps the clinicians in three major ways: a) To take better decisions on case to case basis; b) To design strategies in order to prevent adverse outcomes; c) Last but not least, to make better use of ICU resources.

Evaluation of CA 242 as a tumor marker in gallbladder cancer.

PURPOSE: Gallbladder and pancreas share common embryological origin, and malignancies of these organs may share common tumor antigens. CA 242 is a tumor marker for pancreatic cancer, but has not been studied in gallbladder cancer (GBC). We measured serum CA 242 levels in patients with GBC and compared it with those in patients with gallstones (GS) and healthy volunteers. METHODS: We enrolled consecutive patients with GBC (cases), GS (disease controls), and healthy volunteers (healthy controls). Serum CA 242, CEA, and CA 19-9 levels were measured using ELISA. Receiver operator curve was plotted for all the three markers. RESULTS: We studied 117 patients with GBC, 58 with GS, and 10 healthy volunteers. Among patients with GBC, 81 (69%) also had GB calculi. Patients with GBC more often had elevated CA 242 levels (64%) compared to those with GS (17%; p < 0.001) and healthy controls (0%; p < 0.001). The median levels of CA 242 was higher in the GBC group (59 [199] U/ml) compared to the GS group (10 [13] U/ml; p < 0.001) and the control group (3 [14.5] U/ml; p < 0.001). The sensitivity, specificity, positive predictive value (PPV), and negative predictive values of CA 242 for diagnosis of GBC were 64%, 83%, 88%, and 53%, respectively. At a cutoff of 45 U/ml, the specificity and PPV increased to 100%. CA 242 had higher AOC (0.759) compared to CEA (0.528) and CA 19-9 (0.430). CONCLUSIONS: CA 242 is a promising tumor marker for GBC and performs better than CEA and CA 19-9.

Effect of different doses of carotenoids in isoniazid-rifampicin induced hepatotoxicity in rats.

AIM: Isoniazid (INH) and Rifampicin (RIF) are hepatotoxic drugs. Oxidative stress has been reported as one of the mechanisms of INH+RIF induced hepatotoxicity. METHODS: Intragastric administration of INH and RIF (50 mg/kg body weight/day each) for 28 days in Wistar rats is hepatotoxic, indicated by raised transaminases and histology. Carotenoids have antioxidant properties. Therefore, different doses of carotenoids (2.5, 5, 10 and 20 mg/kg body weight/day) were administered to study the hepatoprotective effect against INH+RIF. RESULTS: The higher doses of carotenoids i.e.10 and 20 mg/kg body weight/day showed partial hepatoprotection indicated by return to normal of liver transaminase level and of liver histology in 33.3% of rats. There was no further protective effect seen by increasing the dose of carotenoids from 10 to 20 mg/kg body weight/day. Lower doses of carotenoids, i.e., 2.5 and 5 mg/kg body weight/day were not effective. CONCLUSION: Thus, a minimum dose with maximum hepatoprotection (10 mg/kg b.wt/ day) was selected as the optimum dose in the present study. The hepatoprotective nature of carotenoids in INH+RIF treated rats may be attributed to their antioxidative property.

Effect of different oral doses of isoniazid-rifampicin in rats.

UNLABELLED: Hepatotoxicity is one of the most serious adverse effects of antituberculosis drugs. The aim of this study was to produce a rat model of isoniazid-rifampicin (INH-RIF) induced hepatotoxicity. MATERIALS AND METHODS: Wistar rats (100-150 g) were treated with different doses of INH i.e. 25, 50 and 75 mg/kg/day with a fixed dose of RIF i.e. 50 mg/kg/day intragastrically for a period of 28 days. Serum glutamate oxaloacetate aminotransferase (SGOT), glutamate pyruvate aminotransferase (SGPT), bilirubin (Bil) and alkaline phosphatase (ALP) were estimated at 0,14, 21 and 28 days in rats. Histological analysis was carried out to assess the liver. RESULTS: Treatment of rats with INH-RIF (50 mg/kg/day each) induced hepatotoxicity as judged by elevated serum SGPT, SGOT, Bil and ALP as compared with their base line. Histological evaluation of INH-RIF induced hepatotoxicity also showed liver damage. CONCLUSION: The present study suggests that 50 mg/kg/day each of INH-RIF was selected as hepatotoxic dose (i.e. minimum dose with maximum hepatotoxicity) in wistar rats.

Effect of garlic on isoniazid and rifampicin-induced hepatic injury in rats.

AIM: To evaluate the hepatoprotective effect of garlic on liver injury induced by isoniazid (ZNH) and rifampicin (RIF). METHODS: Wistar rats weighing 150-200 g were treated orally with 50 mg/kg of INH and RIF daily each for 28 d. For hepatoprotective studies, 0.25 g/kg per day of freshly prepared garlic homogenate was administered orally half an hour before the INH+RIF doses. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and bilirubin were estimated on d 0, 14, 21, and 28 in all the rats. Histological analysis was carried out to assess the injury to the liver. Lipid peroxidation (LPO) as a marker of oxidative stress and non-protein thiols (glutathione) for antioxidant levels were measured in liver homogenate. RESULTS: The treatment of rats with INH+RIF (50 mg/kg per day each) induced hepatotoxicity in all the treated animals as judged by elevated serum ALT, AST, and bilirubin levels, presence of focal hepatocytic necrosis (6/8) and portal triaditis (8/8). Garlic simultaneously administered at a dose of 0.25 g/kg per day prevented the induction of histopathological injuries in INH+RIF co-treated animals, except in 4 animals, which showed only moderate portal triaditis. The histological changes correlated with oxidative stress in INH+RIF treated animals. The group which received 0.25 g/kg per day garlic homogenate along with INH+RIF showed higher levels of glutathione (P<0.05) and low levels of LPO (P<0.05) as compared to INH+RIF treated group. CONCLUSION: Freshly prepared garlic homogenate protects against INH+RIF-induced liver injury in experimental animal model.