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Sample records for post-esophageal variceal ligation

  1. Risk factors for predicting early variceal rebleeding after endoscopic variceal ligation

    PubMed Central

    Xu, Liang; Ji, Feng; Xu, Qin-Wei; Zhang, Mie-Qing

    2011-01-01

    AIM: To analyze the clinical risk factors for early variceal rebleeding after endoscopic variceal ligation (EVL). METHODS: 342 cirrhotic patients with esophageal varices who received elective EVL to prevent bleeding or rebleeding at our endoscopy center between January 2005 and July 2010. were included in this study. The early rebleeding cases after EVL were confirmed by clinical signs or endoscopy. A case-control study was performed comparing the patients presenting with early rebleeding with those without this complication. RESULTS: The incidence of early rebleeding after EVL was 7.60%, and the morbidity of rebleeding was 26.9%. Stepwise multivariate logistic regression analysis showed that four variables were independent risk factors for early rebleeding: moderate to excessive ascites [odds ratio (OR) 62.83, 95% CI: 9.39-420.56, P < 0.001], the number of bands placed (OR 17.36, 95% CI: 4.00-75.34, P < 0.001), the extent of varices (OR 15.41, 95% CI: 2.84-83.52, P = 0.002) and prothrombin time (PT) > 18 s (OR 11.35, 95% CI: 1.93-66.70, P = 0.007). CONCLUSION: The early rebleeding rate after EVL is mainly affected by the volume of ascites, number of rubber bands used to ligate, severity of varices and prolonged PT. Effective measures for prevention and treatment should be adopted before and after EVL. PMID:21876624

  2. The Role of Adjuvant Acid Suppression on the Outcomes of Bleeding Esophageal Varices after Endoscopic Variceal Ligation

    PubMed Central

    Wu, Cheng-Kun; Liang, Chih-Ming; Hsu, Chien-Ning; Hung, Tsung-Hsing; Yuan, Lan-Ting; Nguang, Seng-Howe; Wang, Jiunn-Wei; Tseng, Kuo-Lun; Ku, Ming-Kun; Yang, Shih-Cheng; Tai, Wei-Chen; Shih, Chih-Wei; Hsu, Pin-I; Wu, Deng-Chyang; Chuah, Seng-Kee

    2017-01-01

    The impact of adjuvant acid suppression via proton pump inhibitors or histamine-2 receptor antagonists after endoscopic variceal ligation remains uncertain. We therefore aimed to evaluate the effect of adjuvant acid suppression on the rebleeding and mortality rates in patients who received endoscopic variceal ligation and vasoconstrictor therapy for bleeding esophageal varices. Data from 1997 to 2011 were extracted from the National Health Insurance Research Database in Taiwan. A total of 1576 cirrhotic patients aged > 18 years with a primary diagnosis of acute esophageal variceal bleeding who received endoscopic variceal ligation therapy were screened. After strict exclusion, 637 patients were recruited. The exclusion criteria included patients with gastric variceal bleeding, failure in the control of bleeding, mortality within 12 hours, and history of hepatocellular carcinoma or gastric cancer. Patients were divided into two groups: the vasoconstrictors group (n = 126) and vasoconstrictors plus acid suppression group (n = 511). We observed that the rebleeding and mortality rates were not significantly different between 2 groups during hospitalization and the 15-year follow-up period after discharge. A Charlson score ≥3 (odds ratio: 2.42, 95% confidence interval: 1.55 ~3.79, P = 0.0001), presence of hepatitis C virus (odds ratio: 1.70, 95% confidence interval: 1.15 ~2.52, P = 0.0085), and cirrhosis (odds ratio: 1.69, 95% confidence interval: 1.08 ~2.66, P = 0.0229) were the independent risk factors of mortality after discharge. In conclusion, the results of the current study suggest that adjuvant acid suppression prescription to patients who received endoscopic variceal ligation and vasoconstrictor therapy for bleeding esophageal varices may not change the rebleeding and mortality outcomes compared to that for those who received endoscopic variceal ligation and vasoconstrictor agents without acid suppression. PMID:28118373

  3. Endoscopic band ligation: Beyond prevention and management of gastroesophageal varices

    PubMed Central

    Ji, Jeong-Seon; Cho, Young-Seok

    2013-01-01

    Endoscopic band ligation (EBL) is the preferred endoscopic technique for the endoscopic treatment of acute esophageal variceal bleeding. EBL has also been used to treat nonvariceal bleeding. Recently, Han et al demonstrated that EBL can be a feasible and safe alternate technique for the management of iatrogenic gastric perforation especially in cases in which closure with endoclips is difficult. EBL is technically simpler to perform than other methods and provides a good view of the lesions under direct pressure and suction from the transparent ligation cap. EBL can be used even if the diameter of the perforation is greater than 10 mm or if there is a severe tangential angle. In this commentary, we discuss the efficacy and safety of EBL for the closure of iatrogenic gastrointestinal perforation. We also discuss the advantages and disadvantages of EBL for the treatment of nonvariceal bleeding. PMID:23885137

  4. Changes in Cardiac Varices and Their Clinical Significance after Eradication of Esophageal Varices by Band Ligation

    PubMed Central

    Park, Seung Woon; Lee, Han Ah; Park, Sang Jung; Kim, Tae Hyung; Lee, Jae Min; Suh, Sang Jun; Choi, Hyuk Soon; Kim, Eun Sun; Keum, Bora; Jung, Young Kul; An, Hyonggin; Yim, Hyung Joon; Jeen, Yoon Tae; Yeon, Jong Eun; Lee, Hong Sik; Chun, Hoon Jai; Byun, Kwan Soo; Um, Soon Ho; Kim, Chang Duck

    2016-01-01

    Background and Aims. Cardiac varices (CVs) in patients with type 1 gastroesophageal varices (GOV1s) usually disappear with treatment for esophageal varices (EVs) by endoscopic injection sclerotherapy (EIS). However, whether this applies to patients treated with endoscopic band ligation (EBL) for EVs remains unclear. We evaluated the effect of EVs eradication by EBL on CVs. Methods. We included cirrhotic patients whose EVs had been eradicated using EBL and excluded those who had been treated using EIS, those who had received endoscopic therapy for CVs, and those who were combined with hepatocellular carcinoma. Results. A total of 123 patients were enrolled. The age was 59.7 ± 11.7 years, and 96 patients (78.0%) were men. Thirty-eight patients (30.9%) had EVs only, while 85 (69.1%) had GOV1s. After EVs eradication, the CVs disappeared in 55 patients (64.7%). EVs recurred in 40 patients, with recurrence rates at 1, 2, and 3 years of 16.0%, 29.6%, and 35.6%, respectively, the recurrence being more frequent in patients who had undergone EBL for secondary prophylaxis and in those with persisting CVs after EVs eradication (P = 0.003). Conclusions. CVs frequently disappeared when EVs were eradicated using EBL in patients with GOV1s. Persistence of CVs after EVs eradication by EBL was associated with EVs recurrence. PMID:28116285

  5. Should we add beta-blockers to band ligation for secondary prophylaxis of variceal bleeding?

    PubMed

    Cotoras, Petre; Faúndez, Jorge; Candia, Roberto

    2017-02-23

    Cirrhotic patients who have had an episode of bleeding from gastroesophageal varices are at high risk of rebleeding, despite treatment with endoscopic variceal ligation. Adding beta-blockers could reduce this risk, but it is associated with adverse effects. Searching in Epistemonikos database, which is maintained by screening multiple databases, we identified seven systematic reviews including 21 randomized controlled trials addressing the question of this article. We extracted data, combined the evidence using meta-analysis and generated a summary of findings following the GRADE approach. We concluded the addition of beta-blockers to endoscopic variceal ligation as secondary prophylaxis of variceal bleeding reduces the risk of rebleeding, but probably does not lead to any difference in terms of mortality. Even though it is associated to frequent adverse effects, these would be mild and generally do not lead to discontinuation of treatment.

  6. Cyanoacrylate injection versus band ligation for bleeding from cardiac varices along the lesser curvature of the stomach

    PubMed Central

    Park, Sang Jung; Kim, Yong Kwon; Seo, Yeon Seok; Park, Seung Woon; Lee, Han Ah; Kim, Tae Hyung; Suh, Sang Jun; Jung, Young Kul; Kim, Ji Hoon; An, Hyunggin; Yim, Hyung Joon; Jang, Jae Young; Yeon, Jong Eun; Byun, Kwan Soo

    2016-01-01

    Background/Aims Practice guidelines recommend endoscopic band ligation (EBL) and endoscopic variceal obturation (EVO) for bleeding from esophageal varices and fundal varices, respectively. However, the optimal treatment for bleeding from cardiac varices along the lesser curvature of the stomach (GOV1) remains undefined. This retrospective study compared the efficacy between EBL and EVO for bleeding from GOV1. Methods Patients treated by EBL or EVO via cyanoacrylate injection for bleeding from GOV1 were enrolled. Patients diagnosed with hepatocellular carcinoma or treated with endoscopic injection sclerotherapy were excluded. Results The study included 91 patients treated for bleeding from GOV1. The mean age was 56.3±10.9 years (mean±SD), and 78 of them (85.7%) were men. Overall, 51 and 40 patients were treated with EBL and EVO, respectively. A trend for a higher hemostasis rate was noted in the EVO group (100%) than in the EBL group (82.6%, P=0.078). Varices rebled in 15 patients during follow-up. The rebleeding rate was significantly higher in the EBL group than in the EVO group (P=0.004). During follow-up, 13 patients died (11 in the EBL group and 2 in the EVO group); the survival rate was marginally significant between two groups (P=0.050). The rebleeding-free survival rate was significantly higher in the EVO group than in the EBL group (P=0.001). Conclusion Compared to EBL, EVO offered significantly lower rebleeding rates, significantly higher rebleeding-free survival rates, and a trend for higher hemostasis and survival rates. EVO appears to be the better therapeutic option for bleeding from GOV1. PMID:28081588

  7. Complete Esophageal Obstruction after Endoscopic Variceal Band Ligation in a Patient with a Sliding Hiatal Hernia

    PubMed Central

    Mansour, Munthir; Abdel-Aziz, Yousef; Awadh, Hesham; Shah, Nihar

    2017-01-01

    Complete esophageal obstruction is a rare complication of endoscopic variceal banding, with only 6 cases in the English literature since the introduction of endoscopic variceal banding in 1986. We report a case of complete esophageal obstruction following esophageal banding due to entrapment of part of a sliding hiatal hernia. To our knowledge, our case is one of few with esophageal obstruction post-banding, and the first associated with a hiatal hernia. We recommend caution when performing esophageal banding on patients with a hiatal hernia. PMID:28144613

  8. Emergency endoscopic variceal ligation in cirrhotic patients with blood clots in the stomach but no active bleeding or stigmata increases the risk of rebleeding

    PubMed Central

    Kim, Su Jin; Choi, Cheol Woong; Kang, Dae Hwan; Kim, Hyung Wook; Park, Su Bum; Hong, Young Mi; Yoon, Ki Tae; Cho, Mong; Nam, Hyung Seok; Islam, SM Bakhtiar UI

    2016-01-01

    Background/Aims This study aimed to evaluate the efficacy and safety of emergency variceal ligation for the prevention of rebleeding in cirrhotic patients who are found on initial endoscopy to have blood clots in the stomach but no actively bleeding esophageal and gastric varices or stigmata. Methods This study included 28 cirrhotic patients who underwent emergency prophylactic EVL and 41 who underwent an elective intervention between January 2009 and June 2014. Clinical outcomes were analyzed, including the rebleeding, 6-week mortality, and rebleeding-free survival rates. Results The rebleeding rate was higher in the emergency than in the elective group (28.6% vs. 7.3%, P=0.041). Multivariate analysis showed that emergency prophylactic EVL (odds ratio [OR] = 7.4, 95% confidence interval [CI]=1.634.8, P=0.012) and Child-Pugh score C (OR=10.6, 95% CI=1.4-80.8, P=0.022) were associated with rebleeding. In the emergency group, the gastric varices were associated with rebleeding (OR=12.0, 95% CI=1.7-83.5, P=0.012). Conclusion Emergency EVL may be associated with variceal rebleeding when blood clots are present in the stomach without active esophageal and gastric variceal bleeding or stigmata. Elective intervention should be considered as a safer strategy for preventing variceal rebleeding in this situation. PMID:28081590

  9. Endoscopic management of esophageal varices.

    PubMed

    Poza Cordon, Joaquin; Froilan Torres, Consuelo; Burgos García, Aurora; Gea Rodriguez, Francisco; Suárez de Parga, Jose Manuel

    2012-07-16

    The rupture of gastric varices results in variceal hemorrhage, which is one the most lethal complications of cirrhosis. Endoscopic therapies for varices aim to reduce variceal wall tension by obliteration of the varix. The two principal methods available for esophageal varices are endoscopic sclerotherapy (EST) and band ligation (EBL). The advantages of EST are that it is cheap and easy to use, and the injection catheter fits through the working channel of a diagnostic gastroscope. Endoscopic variceal ligation obliterates varices by causing mechanical strangulation with rubber bands. The following review aims to describe the utility of EBL and EST in different situations, such as acute bleeding, primary and secondary prophylaxis.

  10. Cyanoacrylate Injection Compared with Band Ligation for Acute Gastric Variceal Hemorrhage: A Meta-Analysis of Randomized Controlled Trials and Observational Studies

    PubMed Central

    Huai, Jiaping; Chen, Yanping

    2014-01-01

    Background. Cyanoacrylate injection (GVO) and band ligation (GVL) are effective treatments for gastric variceal hemorrhage. However, data on the optimal treatment are still controversial. Methods. For our overall analysis, relevant studies were identified from several databases. For each outcome, data were pooled using a fixed-effect or random-effects model according to the result of a heterogeneity test. Results. Seven studies were included. Compared with GVL, GVO was associated with increased likelihood of hemostasis of active bleeding (odds ratio [OR] = 2.32; 95% confidence interval [CI] = 1.19–4.51) and a longer gastric variceal rebleeding-free period (hazard ratio = 0.37; 95% CI = 0.24–0.56). No significant differences were observed between GVL and GVO for mortality (hazard ratio = 0.66; 95% CI = 0.43–1.02), likelihood of variceal obliteration (OR = 0.89; 95% CI = 0.52–1.54), number of treatment sessions required for complete variceal eradication (weighted mean difference = −0.45; 95% CI = −1.14–0.23), or complications (OR = 1.02; 95% CI = 0.48–2.19). Conclusion. GVO may be superior to GVL for achieving hemostasis and preventing recurrence of gastric variceal rebleeding but has no advantage over GVL for mortality and complications. Additional studies are warranted to enable definitive conclusions. PMID:24868204

  11. Addition of Somatostatin After Successful Endoscopic Variceal Ligation Does not Prevent Early Rebleeding in Comparison to Placebo: A Double Blind Randomized Controlled Trial

    PubMed Central

    Kumar, Ashish; Jha, Sanjeev K.; Mittal, Vibhu V.; Sharma, Praveen; Sharma, Barjesh C.; Sarin, Shiv K.

    2015-01-01

    Background Efficacy of endoscopic sclerotherapy in controlling acute variceal bleeding is significantly improved when vasoactive drug is added. Endoscopic variceal ligation (EVL) is superior to sclerotherapy. Whether efficacy of EVL will also improve with addition of somatostatin is not known. We compared EVL plus somatostatin versus EVL plus placebo in control of acute variceal bleeding. Methods Consecutive cirrhotic patients with acute esophageal variceal bleeding were enrolled. After emergency EVL, patients were randomized to receive either somatostatin (250 mcg/hr) or placebo infusion. Primary endpoint was treatment failure within 5 days. Treatment failure was defined as fresh hematemesis ≥2 h after start of therapy, or a 3 gm drop in Hb, or death. Results 61 patients were enrolled (EVL plus somatostatin group, n = 31 and EVL plus placebo group, n = 30). The baseline characteristics were similar. Within the initial 5-day period, the frequency of treatment failure was similar in both the groups (EVL plus somatostatin group 8/31 [26%] versus EVL plus placebo group 7/30 [23%]; P = 1.000). The mortality was also similar in the two groups (3/31 [10%] vs. 3/30 [10%]; P = 1.000). Baseline HVPG ≥19 mm Hg and active bleeding at index endoscopy were independent predictors of treatment failure. Conclusions Addition of somatostatin infusion to EVL therapy does not offer any advantage in control of acute variceal bleeding or reducing mortality. The reason for this may be its failure to maintain sustained reduction in portal pressure for five days. Active bleeding at index endoscopy and high baseline HVPG should help choose early alternative treatment options. Trial registered with ClincalTrials.gov vide NCT01267669. PMID:26628838

  12. Management of rectal varices in portal hypertension

    PubMed Central

    Al Khalloufi, Kawtar; Laiyemo, Adeyinka O

    2015-01-01

    Rectal varices are portosystemic collaterals that form as a complication of portal hypertension, their prevalence has been reported as high as 94% in patients with extrahepatic portal vein obstruction. The diagnosis is typically based on lower endoscopy (colonoscopy or sigmoidoscopy). However, endoscopic ultrasonography has been shown to be superior to endoscopy in diagnosing rectal varices. Color Doppler ultrasonography is a better method because it allows the calculation of the velocity of blood flow in the varices and can be used to predict the bleeding risk in the varices. Although rare, bleeding from rectal varices can be life threatening. The management of patients with rectal variceal bleeding is not well established. It is important to ensure hemodynamic stability with blood transfusion and to correct any coagulopathy prior to treating the bleeding varices. Endoscopic injection sclerotherapy has been reported to be more effective in the management of active bleeding from rectal varices with less rebleeding rate as compared to endoscopic band ligation. Transjugular intrahepatic portsystemic shunt alone or in combination with embolization is another method used successfully in control of bleeding. Balloon-occluded retrograde transvenous obliteration is an emerging procedure for management of gastric varices that has also been successfully used to treat bleeding rectal varices. Surgical procedures including suture ligation and porto-caval shunts are considered when other methods have failed. PMID:26730278

  13. Endoscopic management of esophagogastric varices in Japan

    PubMed Central

    Ichikawa, Tatsuki; Taura, Naota; Miuma, Satoshi; Isomoto, Hajime; Nakao, Kazuhiko

    2014-01-01

    Esophagogastric varices are the most common complication in patients with portal hypertension, and endoscopy plays an important role in their diagnosis and in the prevention of acute bleeding from these structures. Recently, new modalities such as endoscopic ultrasonography (EUS) and narrow-band imaging have been introduced for the diagnosis of esophagogastric varices. In Japan, endoscopic therapy has become the first choice for the treatment of acutely bleeding esophageal or gastric varices. The two principal methods used to treat esophageal varices are endoscopic injection sclerotherapy (EIS) and endoscopic variceal ligation (EVL). Recently, combinations of EIS plus EVL and EVL plus argon plasma coagulation were reported to be more effective than EVL or EIS alone. Additionally, endoscopic cyanoacrylate injection is superior to EIS and EVL for the treatment of acutely bleeding gastric varices. PMID:25333017

  14. Stomal Varices: Treatment by Percutaneous Transhepatic Coil Embolization

    SciTech Connect

    Kishimoto, Keiko; Hara, Akihiko; Arita, Takeshi; Tsukamoto, Katsuhiko; Matsui, Norichika; Kaneyuki, Toshihiro; Matsunaga, Naofumi

    1999-11-15

    Bleeding from stomal varices in a patient with portal hypertension, uncontrolled by surgical ligation and sclerotherapy, was well controlled by percutaneous transhepatic embolization with platinum and stainless-steel coils.

  15. Treatment modalities for bleeding esophagogastric varices.

    PubMed

    Yoshida, Hiroshi; Mamada, Yasuhiro; Taniai, Nobuhiko; Yoshioka, Masato; Hirakata, Atsushi; Kawano, Youichi; Mizuguchi, Yoshiaki; Shimizu, Tetsuya; Ueda, Junji; Uchida, Eiji

    2012-01-01

    Bleeding from esophageal varices (EVs) or gastric varices (GVs) is a catastrophic complication of chronic liver disease. In this paper, we review the management of bleeding EVs and GVs. DIAGNOSIS OF EVS AND GVS: The grading system for esophagogastric varices proposed by the Japan Society for Portal Hypertension classifies GVs into those involving the cardia (Lg-c), the fundus (Lg-f), and both the cardia and the fundus (Lg-cf). In this review, we divide GVs into 2 categories: Lg-c (cardiac varices: CVs) and Lg-cf or Lg-f (fundal varices: FVs). TREATMENT MODALITIES FOR EVS AND GVS: Treatment modalities for EVs and GVs include placement of a Sengstaken-Blakemore tube, pharmacologic therapy, surgery, interventional radiology, and endoscopic treatment. MANAGEMENT OF BLEEDING EVS AND GVS: In Japan, endoscopic treatment has recently become the therapy of choice for bleeding EVs or GVs. In other countries, especially the United States, vasoactive drugs and endoscopic treatment are routinely used to manage variceal hemorrhage. BLEEDING EVS: Endoscopic variceal ligation is useful for controlling bleeding from EVs. However, confirmation of ligation precisely at the site of bleeding is usually difficult in patients with massive variceal bleeding. The site of acute bleeding can generally be identified by means of water instillation and suction. Ligation is then performed at the bleeding point. If endoscopic hemostasis is unsuccessful, a Sengstaken-Blakemore tube is used as a temporary bridge to other treatments. Transportal obliteration is useful for blocking variceal blood flow. BLEEDING GVS: Endoscopic injection sclerotherapy with a tissue adhesive, such as N-butyl-cyanoacrylate or isobutyl-2-cyanoacrylate, is effective for acute bleeding from GVs. However, bleeding from the GV injection site and rebleeding from the rupture point have been reported in patients receiving endoscopic injection sclerotherapy. If endoscopic hemostasis is unsuccessful, a Sengstaken-Blakemore tube

  16. Overview of the methods and therapies for the primary prevention of variceal bleeding.

    PubMed

    Tripathi, Dhiraj

    2010-08-01

    Patients with cirrhosis develop varices at a rate of 5% per year, and a third of patients with high-risk varices will bleed. The mortality associated with variceal haemorrhage is typically 20%, and still exceeds that of myocardial infarction. Current options to prevent the first variceal bleed include noncardioselective beta-blockers or variceal band ligation. In patients with medium-to-large esophageal varices, both therapies reduce the risk of bleeding by 50% or more. The choice of therapy should take into account patient choice and local availability; although for most patients drug therapy is the preferred first-line treatment. There has been recent interest in carvedilol, with promising initial data. Further studies are necessary before universal recommendation. There is no role for drug therapy in patients without varices, and the use of beta-blockers for patients with small varices is controversial.

  17. MANAGEMENT OF VARICEAL HEMORRHAGE: CURRENT CONCEPTS

    PubMed Central

    COELHO, Fabricio Ferreira; PERINI, Marcos Vinícius; KRUGER, Jaime Arthur Pirola; FONSECA, Gilton Marques; de ARAÚJO, Raphael Leonardo Cunha; MAKDISSI, Fábio Ferrari; LUPINACCI, Renato Micelli; HERMAN, Paulo

    2014-01-01

    Introduction The treatment of portal hypertension is complex and the the best strategy depends on the underlying disease (cirrhosis vs. schistosomiasis), patient's clinical condition and time on it is performed (during an acute episode of variceal bleeding or electively, as pre-primary, primary or secondary prophylaxis). With the advent of new pharmacological options and technical development of endoscopy and interventional radiology treatment of portal hypertension has changed in recent decades. Aim To review the strategies employed in elective and emergency treatment of variceal bleeding in cirrhotic and schistosomotic patients. Methods Survey of publications in PubMed, Embase, Lilacs, SciELO and Cochrane databases through June 2013, using the headings: portal hypertension, esophageal and gastric varices, variceal bleeding, liver cirrhosis, schistosomiasis mansoni, surgical treatment, pharmacological treatment, secondary prophylaxis, primary prophylaxis, pre-primary prophylaxis. Conclusion Pre-primary prophylaxis doesn't have specific treatment strategies; the best recommendation is treatment of the underlying disease. Primary prophylaxis should be performed in cirrhotic patients with beta-blockers or endoscopic variceal ligation. There is controversy regarding the effectiveness of primary prophylaxis in patients with schistosomiasis; when indicated, it is done with beta-blockers or endoscopic therapy in high-risk varices. Treatment of acute variceal bleeding is systematized in the literature, combination of vasoconstrictor drugs and endoscopic therapy, provided significant decline in mortality over the last decades. TIPS and surgical treatment are options as rescue therapy. Secondary prophylaxis plays a fundamental role in the reduction of recurrent bleeding, the best option in cirrhotic patients is the combination of pharmacological therapy with beta-blockers and endoscopic band ligation. TIPS or surgical treatment, are options for controlling rebleeding on

  18. Embolization of Bleeding Stomal Varices by Direct Percutaneous Approach

    SciTech Connect

    Arulraj, Ramakrishnan; Mangat, Kamarjit S.; Tripathi, Dhiraj

    2011-02-15

    Stomal varices can occur in patients with stoma in the presence of portal hypertension. Suture ligation, sclerotherapy, angiographic embolization, stoma revision, beta blockade, portosystemic shunt, and liver transplantation have been described as therapeutic options for bleeding stomal varices. We report the case of a 21-year-old patient with primary sclerosing cholangitis and colectomy with ileostomy for ulcerative colitis, where stomal variceal bleeding was successfully treated by direct percutaneous embolization. We consider percutaneous embolization to be an effective way of treating acute stomal bleeding in decompensated patients while awaiting decisions regarding shunt procedures or liver transplantation.

  19. Upper gastrointestinal ectopic variceal bleeding treated with various endoscopic modalities

    PubMed Central

    Park, Sang Woo; Cho, Eunae; Jun, Chung Hwan; Choi, Sung Kyu; Kim, Hyun Soo; Park, Chang Hwan; Rew, Jong Sun; Cho, Sung Bum; Kim, Hee Joon; Han, Mingui; Cho, Kyu Man

    2017-01-01

    Abstract Rationale: Ectopic variceal bleeding is a rare (2–5%) but fatal gastrointestinal bleed in patients with portal hypertension. Patients with ectopic variceal bleeding manifest melena, hematochezia, or hematemesis, which require urgent managements. Definitive therapeutic modalities of ectopic varices are not yet standardized because of low incidence. Various therapeutic modalities have been applied on the basis of the experiences of experts or availability of facilities, with varying results. Patient concerns: We have encountered eight cases of gastrointestinal ectopic variceal bleeding in five patients in the last five years. Diagnoses: All patients were diagnosed with liver cirrhosis presenting melena or hematemesis. Interventions: All patients were treated with various endoscopic modalities (endoscopic variceal obturation [EVO] with cyanoacrylate in five cases, endoscopic variceal band ligation (EVL) in two cases, hemoclipping in one case). Outcomes: Satisfactory hemostasis was achieved without radiologic interventions in all cases. EVO and EVL each caused one case of portal biliopathy, and EVL induced ulcer bleeding in one case. Lessons: EVO generally accomplished better results of variceal obturations than EVL or hemoclipping, without serious adverse events. EVO may be an effective modality for control of ectopic variceal bleeding without radiologic intervention or surgery. PMID:28072750

  20. Colorectal variceal bleeding in patients with extrahepatic portal vein thrombosis and idiopathic portal hypertension.

    PubMed

    Orozco, H; Takahashi, T; Mercado, M A; Prado-Orozco, E; Ferral, H; Hernandez-Ortiz, J; Esquivel, E

    1992-03-01

    We report three patients with colonic variceal bleeding secondary to portal hypertension, 0.5% of all cases with hemorrhagic portal hypertension studied by us in the last 16 years. One patient had idiopathic portal hypertension, and the others had extrahepatic portal vein thrombosis. Colonic varices were documented in all three cases by angiogram; large arteriovenous fistulas in the territory of the superior mesenteric artery and between the inferior mesenteric artery and hemorrhoidal veins were demonstrated in one patient. Two patients underwent colonoscopy; colonic varices were seen in only one. Two patients also had bled from esophagogastric varices. One patient underwent descending colon and sigmoid resection after failure to control bleeding with ligation of arterial supply; one patient underwent the Sugiura procedure, plus transanal ligation of hemorrhoids and rectal varices. At 3 months, 2 years, and 4 years of follow-up, the patients were in good general condition without any evidence of rebleeding.

  1. Incidence of HCV induced—Esophageal varices in Egypt

    PubMed Central

    Abdel-aty, Mahmoud; Fouad, Mahmoud; Sallam, Mohammad M.; Elgohary, Elsayed A.; Ismael, Ali; Nawara, Abdallah; Hawary, Baha; Tag-Adeen, Mohammed; Khaled, Salama

    2017-01-01

    Abstract Esophageal varices is one of the most important comorbidity related liver cirrhosis, patients usually presented with hematemesis, melena, or both, ultimately 20% is the mortality during the first attack, hence we aimed to investigate the incidence of such esophageal varices related chronic Hepatitis C virus (HCV) in randomized Egyptian population. One thousand eighteen Egyptian patients, aged between 17 and 58 years, positive for Hepatitis C virus genotype 4 (HCV-4) by enzyme linked immunosorbent assay Ab and HCV RNA-polymerase chain reaction were screened for the presence of esophageal varices. Incidence of esophageal varices was 62.3%; 635 patients, those with large Esophageal varices (LEVs) was 47.4%; 301 patients. Model for end-stage liver disease (MELD) score has not been significantly improved post variceal band ligation (VBL). Using 2D U/S was useful for EVs prediction. Incidence of esophageal varices in HCV Egyptian patients still high, valuable knowledge would be helpful in clinical field have been discovered by data mining computational intelligent analysis using in practical medicine to improve overall health care. PMID:28121921

  2. Prevention and treatment of variceal haemorrhage in 2017.

    PubMed

    Brunner, Felix; Berzigotti, Annalisa; Bosch, Jaime

    2017-01-01

    Variceal haemorrhage is a major complication of portal hypertension that still causes high mortality in patients with cirrhosis. Improved knowledge of the pathophysiology of portal hypertension has recently led to a more comprehensive approach to prevent all the complications of this condition. Thus, optimal treatment of portal hypertension requires a strategy that takes into account the clinical stage of the disease and all the major variables that affect the risk of progression to the next stage and death. In patients with compensated liver disease, the correction of factors influencing the progression of fibrosis, in particular aetiologic factors, is now feasible in many cases and should be achieved to prevent the development or progression of gastroesophageal varices and hepatic decompensation. Once gastroesophageal varices have developed, non-selective beta-blockers remain the cornerstone of therapy. Carvedilol provides a greater decrease in portal pressure and is currently indicated as a first-choice therapy for primary prophylaxis. The treatment of acute variceal haemorrhage includes a combination of vasoactive drugs, antibiotics and endoscopic variceal band ligation. In high-risk patients, the early use of transjugular intrahepatic portosystemic shunt (TIPS) lowers the risk of re-bleeding and improves survival. Transjugular intrahepatic portosystemic shunt is the choice for uncontrolled variceal bleeding; a self-expandable metal stent or balloon tamponade can be used as a bridging measure. The combination of non-selective beta-blockers and endoscopic variceal band ligation reduces the risk of recurrent variceal bleeding and improves survival. In these cases, statins seem to further improve survival. Transjugular intrahepatic portosystemic shunt is indicated in patients who rebleed during secondary prophylaxis.

  3. Secondary prophylaxis for esophageal variceal bleeding.

    PubMed

    Albillos, Agustín; Tejedor, Marta

    2014-05-01

    Combination therapy with beta-blockers and endoscopic band ligation (EBL) is the standard prophylaxis of esophageal variceal rebleeding in cirrhosis. Beta-blockers are the backbone of combination therapy, since their benefit extend to other complications of portal hypertension. EBL carries the risk of post-banding ulcer bleeding, which explains why overall rebleeding is reduced when beta-blockers are added to EBL, and not when EBL is added to beta-blockers. TIPS is the rescue treatment, but it could be considered as first choice in patients that first bleed while on beta-blockers, those with contraindications to beta-blockers or with refractory ascites, and those with fundal varices.

  4. Tubal ligation

    MedlinePlus

    ... tying; Tying the tubes; Hysteroscopic tubal occlusion procedure; Contraception - tubal ligation; Family planning - tubal ligation ... Tubal ligation is considered a permanent form of birth control. It is NOT recommended as a short-term ...

  5. Endoscopic treatment of esophageal varices in patients with liver cirrhosis

    PubMed Central

    Triantos, Christos; Kalafateli, Maria

    2014-01-01

    Variceal bleeding is a life-threatening complication of portal hypertension with a six-week mortality rate of approximately 20%. Patients with medium- or large-sized varices can be treated for primary prophylaxis of variceal bleeding using two strategies: non-selective beta-blockers (NSBBs) or endoscopic variceal ligation (EVL). Both treatments are equally effective. Patients with acute variceal bleeding are critically ill patients. The available data suggest that vasoactive drugs, combined with endoscopic therapy and antibiotics, are the best treatment strategy with EVL being the endoscopic procedure of choice. In cases of uncontrolled bleeding, transjugular intrahepatic portosystemic shunt (TIPS) with polytetrafluoroethylene (PTFE)-covered stents are recommended. Approximately 60% of the patients experience rebleeding, with a mortality rate of 30%. Secondary prophylaxis should start on day six following the initial bleeding episode. The combination of NSBBs and EVL is the recommended management, whereas TIPS with PTFE-covered stents are the preferred option in patients who fail endoscopic and pharmacologic treatment. Apart from injection sclerotherapy and EVL, other endoscopic procedures, including tissue adhesives, endoloops, endoscopic clipping and argon plasma coagulation, have been used in the management of esophageal varices. However, their efficacy and safety, compared to standard endoscopic treatment, remain to be further elucidated. There are safety issues accompanying endoscopic techniques with aspiration pneumonia occurring at a rate of approximately 2.5%. In conclusion, future research is needed to improve treatment strategies, including novel endoscopic techniques with better efficacy, lower cost, and fewer adverse events. PMID:25278695

  6. Bleeding esophageal varices

    MedlinePlus

    ... medicine may be injected into the varices. A rubber band may be placed around the bleeding veins ( ... nadolol that reduce the risk of bleeding. A rubber band can be placed around the bleeding veins ...

  7. Percutaneous Transhepatic Embolization of Bleeding Rectal Varices Using A New Embolic And Sclerotic Mixture Augmented By Amplatzer Vascular Plug 2

    PubMed Central

    Abdel-Aal, Ahmed Kamel; Dawoud, Nabila; Moustafa, Amr Soliman; Hamed, Maysoon F; Saddekni, Souheil

    2016-01-01

    We report a case of 59-year-old female with non-alcoholic-steato-hepatitis (NASH) induced cirrhosis, who presented with hematochezia. The patient had a history of bleeding esophageal varices treated with endoscopic variceal ligation (EVL). Colonoscopy showed large rectal varices which were the source of her lower gastrointestinal bleeding (LGIB). Since endoscopic treatment for LGIB are limited, and because the patient had portal vein thrombosis which contraindicated transjugular intrahepatic portosystemic shunt (TIPS), we performed percutaneous transhepatic embolization of her rectal varices using a new mixture of embolic and sclerotic agents, followed by Amplatzer plug 2 (AVP 2). To our knowledge, the use of this new mixture with the AVP 2 in the rectal varices treatment has not been previously published in literature. Our case provides an alternative treatment modality that can be used for rectal varices treatment, when TIPS and endoscopic management fails or is contraindicated. PMID:27761198

  8. Management of acute variceal bleeding using hemostatic powder

    PubMed Central

    El-Mikkawy, Ahmed; Abdalla, Haitham; Mostafa, Ibrahim; Devière, Jacques

    2015-01-01

    Background and objectives This study aimed to test the safety and efficacy of Hemospray® for emergency control of acute variceal bleeding (AVB) due to portal hypertension in cirrhotic patients. Patients and methods This single-arm, prospective trial, conducted at two hospitals in Belgium and Egypt, included patients admitted to the emergency room with hematemesis and/or melena and known or suspected liver cirrhosis. All patients received urgent hemodynamic stabilization, octreotide (50 mcg bolus then 25 mcg/hour for 24 hours) and intravenous ceftriaxone (1 g/hour). Endoscopy to confirm AVB and Hemospray® application (if indicated) was performed within six hours of admission. Patients were kept under observation for 24 hours and underwent second endoscopy and definitive therapy (band ligation and/or cyanoacrylate injection in cases of gastric varices) the next day. Results Thirty-eight patients were admitted for suspected AVB, and 30 of these had confirmed AVB (70% male; mean age 59.5 years (range, 32.0–73 years)). Child-Pugh class C liver disease was present in 53.4%. Esophageal varices were observed in 83.4% of patients, gastric varices in 10%, and duodenal varices in 6.6%. Spurting bleeding at the time of endoscopy was observed in 43.4%. One patient developed hematemesis six hours after Hemospray® application and underwent emergency endoscopic band ligation. No major adverse events or mortalities were observed during 15-day follow-up. Conclusion Hemospray® application was safe and effective at short-term follow-up for emergency treatment of AVB in cirrhotic patients. PMID:26137303

  9. Cyanoacrylate glue in the management of gastric varices.

    PubMed

    Consolo, P; Luigiano, C; Giacobbe, G; Scaffidi, M G; Pellicano, R; Familiari, L

    2009-02-01

    Gastric varices (GV) are less common than esophageal varices, but their management represents a particular challenge. When bleeding occurs is usually severe, requiring immediate supportive intensive care and has a high mortality rate. The best management of GV is supposed to be with a multidisciplinary approach and close cooperation between gastroenterologists, interventional radiologists and the surgical team. Many studies in literature reported high success rates with intravariceal injection of cyanoacrylate in acute GV bleeding. This agent obliterates the variceal lumen by solidification within the vein and more than 80% primary obliteration rates are achieved. In comparison with other endoscopic techniques as variceal band ligation or sclerotherapy with ethanolamine oleate, alcohol and sodium tetradecyl sulphate, cyanoacrylate has shown to be more effective, with a decrease in complications and mortality rates. The cyanoacrylate has shown effective also in the secondary prophylaxis with an incidence of re-bleeding that ranges between 15% and 30%. Actually, there is no scientific evidence supporting the application of cyanoacrylate in primary prophylaxis of bleeding from GV. Significant procedural, septic and embolic complications have been reported with cyanoacrylate glue injection. In conclusion, the endoscopic treatment with cyanoacrylate of actively bleeding GV, as well as the prophylaxis of the re-bleeding, is a safe and effective procedure and should be considered as a first-line therapy, whenever available.

  10. Emergency management of bleeding esophageal varices: Drugs, bands or sleep?

    PubMed Central

    Yan, Brian M; Lee, Samuel S

    2006-01-01

    Variceal bleeding is a severe complication of cirrhosis leading to significant morbidity and mortality. Treatment of acute variceal bleeding has improved dramatically since the era of the mechanical balloon tamponade. These advances include endoscopic band ligation or sclerotherapy, and vasoactive pharmacological options such as somatostatin, octreotide, vasopressin and terlipressin. Evidence from a multitude of clinical trials and meta-analyses comparing endoscopic and pharmacological treatments suggests near equivalence in efficacy for initial hemostasis, mortality and rate of rebleeding. This raises the question of whether on-call gastroenterologists should be performing emergency endoscopic treatment in the middle of the night or start pharmacological treatment and delay endoscopy until optimal patient and working conditions the next morning. The present review analyzes the available comparative data between endoscopic and pharmacological treatment options. Although the literature cannot yet definitively answer the question posed, the authors suggest that delaying endoscopic treatment until the next morning may be the most reasonable practical approach. PMID:16550260

  11. An update on the management of acute esophageal variceal bleeding.

    PubMed

    Cabrera, Lourdes; Tandon, Puneeta; Abraldes, Juan G

    2017-01-01

    The mortality rate in acute variceal haemorrhage remains high (around 15%). Treatment is based on the combined use of vasoactive drugs, endoscopic band ligation, and prophylactic antibiotics. Effective resuscitation (haemostasis, volume management) is essential to prevent complications. Treatment failure is best managed by transjugular intrahepatic portosystemic shunt (TIPS). Balloon tamponade or specifically designed covered oesophageal stents can be used as a bridge to definitive therapy in unstable patients. Early, pre-emptive TIPS should be the first choice in patients at high risk of treatment failure (Child-Pugh B with active bleeding or Child-Pugh C<14). This article reviews the most recent advances in the management of variceal bleeding and discusses the recent recommendations of the Baveno VI consensus conference.

  12. Tubal Ligation

    MedlinePlus

    ... The insert causes scar tissue to form and seal off the tubes. Tubal ligation is an abdominal ... instruments passed through the abdominal wall, your doctor seals the fallopian tubes by destroying segments of the ...

  13. Endovascular management of gastric varices.

    PubMed

    Saad, Wael E

    2014-11-01

    Bleeding from gastric varices is a major complication of portal hypertension. Although less common than bleeding associated with esophageal varices, gastric variceal bleeding has a higher mortality. From an endovascular perspective,transjugular intrahepatic portosystemic shunts (TIPS) to decompress the portal circulation and/or balloon-occluded retrograde transvenous obliteration (BRTO) are utilized to address bleeding gastric varices. Until recently, there was a clear medical cultural divide between the strategy of decompressing the portal circulation (TIPS creation, for example) and transvenous obliteration for the management of gastric varices. However, the practice of BRTO is gaining acceptance in the United States and its practice is spreading rapidly. Recently, the American College of Radiology has identified BRTO to be a viable alternative to TIPS in particular anatomical and clinical scenarios. However, the anatomical and clinical applications of BRTO were not defined beyond the conservative approach of resorting to BRTO in non-TIPS candidates. The article discusses the outcomes of BRTO and TIPS for the management of gastric varices individually or in combination. Definitions, endovascular technical concepts and contemporary vascular classifications of gastric variceal systems are described in order to help grasp the complexity of the hemodynamic pathology and hopefully help define the pathology better for future reporting and lay the ground for more defined stratification of patients not only based on comorbidity and hepatic reserve but on anatomy and hemodynamic classifications.

  14. Octreotide in variceal bleeding.

    PubMed Central

    Burroughs, A K

    1994-01-01

    Bleeding from oesophageal varices has a high death rate. Injection sclerotherapy is the most appropriate treatment but facilities for this are not always available. Balloon tamponade and vasoactive therapy may be used as stop gap measures. Somatostatin and octreotide are therapeutic candidates for the treatment of variceal bleeding and there are several trials that have compared somatostatin and octreotide with other treatments for this condition. The results of these trials are summarised and discussed. A meta analysis of the group of trials of placebo or H2 antagonists v somatostatin or octreotide showed a significant advantage of somatostatin or octreotide in terms of efficacy, but no difference in mortality. The trials discussed seem to show that somatostatin and octreotide are at least as effective as other treatments, with the benefit of fewer adverse effects, and thus represent the best vasoactive agents. Additionally, they may have a role as adjuvant treatment to emergency sclerotherapy for active bleeders and this must be further investigated. PMID:8206396

  15. Improved Survival with the Patients with Variceal Bleed

    PubMed Central

    Sharma, Praveen; Sarin, Shiv K.

    2011-01-01

    Variceal hemorrhage is a major cause of death in patients with cirrhosis. Over the past two decades new treatment modalities have been introduced in the management of acute variceal bleeding (AVB) and several recent studies have suggested that the outcome of patients with cirrhosis and AVB has improved. Improved supportive measures, combination therapy which include early use of portal pressure reducing drugs with low rates of adverse effects (somatostatin, octerotide or terlipressin) and endoscopic variceal ligation has become the first line treatment in the management of AVB. Short-term antibiotic prophylaxis, early use of lactulose for prevention of hepatic encephalopathy, application of early transjugular intrahepatic portasystemic shunts (TIPS), fully covered self-expandable metallic stent in patients for AVB may be useful in those cases where balloon tamponade is considered. Early and wide availability of liver transplantation has changed the armamentarium of the clinician for patients with AVB. High hepatic venous pressure gradient (HVPG) >20 mmHg in AVB has become a useful predictor of outcomes and more aggressive therapies with early TIPS based on HVPG measurement may be the treatment of choice to reduce mortality further. PMID:21994853

  16. Improved survival with the patients with variceal bleed.

    PubMed

    Sharma, Praveen; Sarin, Shiv K

    2011-01-01

    Variceal hemorrhage is a major cause of death in patients with cirrhosis. Over the past two decades new treatment modalities have been introduced in the management of acute variceal bleeding (AVB) and several recent studies have suggested that the outcome of patients with cirrhosis and AVB has improved. Improved supportive measures, combination therapy which include early use of portal pressure reducing drugs with low rates of adverse effects (somatostatin, octerotide or terlipressin) and endoscopic variceal ligation has become the first line treatment in the management of AVB. Short-term antibiotic prophylaxis, early use of lactulose for prevention of hepatic encephalopathy, application of early transjugular intrahepatic portasystemic shunts (TIPS), fully covered self-expandable metallic stent in patients for AVB may be useful in those cases where balloon tamponade is considered. Early and wide availability of liver transplantation has changed the armamentarium of the clinician for patients with AVB. High hepatic venous pressure gradient (HVPG) >20 mmHg in AVB has become a useful predictor of outcomes and more aggressive therapies with early TIPS based on HVPG measurement may be the treatment of choice to reduce mortality further.

  17. Radionuclide transit in esophageal varices

    SciTech Connect

    Yeh, S.H.; Wang, S.J.; Wu, L.C.; Liu, R.S.; Tsai, Y.T.; Chiang, T.T.

    1985-05-01

    This study assessed esophageal motility in patients with esophageal varices by radionuclide transit studies. Data were acquired in list mode after an oral dose of 0.5 mCi Tc-99m sulfur colloid in 10 ml of water in the supine position above a low-energy all-purpose collimator of a gamma camera. The condensed image (CI) superimposed with a centroid curve was also produced in each case. Twenty-five normal subjects (N) and 32 patients (pts) with esophageal varices by endoscopy (large varices in Grades IV and V in 8 and small varices in Grade III or less in 24) were studied. TMTT, RTT, RF, and RI were all significantly increased in pts as compared to N. Especially, the transit time for the middle third (6.7 +- 2.6 sec vs 3.5 +- 0.9 sec in N, rho < 0.005) had the optimal sensitivy and specificity of 88% each at the cutoff value of 4.2 sec as determined by ROC analysis. In summary, radionuclide transit disorders occur in the majority of pts with esopageal varices. The middle RTT and CI are both optimal in sensitivity and specificity for detecting the abnormalities.

  18. Endoscopic Approaches to the Treatment of Variceal Hemorrhage in Hemodialysis-Dependent Patients

    PubMed Central

    Ma, Lili; Zeng, Xiaoqing; Wang, Jian; Chen, Jie

    2016-01-01

    Background. Esophagogastric variceal hemorrhage leads to challenging situation in chronic kidney disease patients on maintenance hemodialysis. Aims. To determine the safety and efficacy of endoscopic approaches to patients with hemodialysis-dependent concomitant with esophagogastric varices. Methods. Medical records were reviewed from January 1, 2004, to December 31, 2015, in our hospital. Five consecutive hemodialysis-dependent patients with variceal hemorrhage who underwent endoscopic treatments were retrospectively studied. Results. The median age of the patients was 54 years (range 34–67 years) and the median follow-up period was 21.3 months (range 7–134 months). All the patients received a total of three times heparin-free hemodialysis 24 hours before and no more than 24 hours and 72 hours after endoscopic treatment. They successfully had endoscopic variceal ligation, endoscopic injection sclerotherapy, and/or N-butyl cyanoacrylate injection. The short-term efficacy is satisfying and long-term follow-up showed episodes of rebleeding. Conclusions. Endoscopic approaches are the alternative options in the treatment of upper gastroenterology variceal hemorrhage in hemodialysis-dependent patients without severe complications. PMID:28105048

  19. Is computerised tomography better than fibreoptic gastroscopy for early detection of gastric varices?

    PubMed Central

    Kekilli, Murat; Beyazıt, Yavuz; Okten, Sarper; Tanoglu, Alpaslan; Sasmaz, Nurgul

    2016-01-01

    Introduction Video endoscopic diagnosis of gastric varices is particularly limited, owing to the deep submucosal or subserosal location of the varices and the normal appearance of the overlying mucosa. Aim We present and emphasise the value of computerised tomography (CT) examination in the early detection of gastric varices (GVs). Material and methods In this retrospective study, a total of 216 consecutive patients with cirrhosis were evaluated at the Turkiye Yuksek Ihtisas Training and Research Hospital between September 2008 and March 2011. Results One hundred and thirty patients with cirrhosis were enrolled in the study. The mean age of the male (88 cases) patients was 59.45 ±2.42 years, and the mean age of the female (42 cases) patients was 56.29 ±1.14 years. Computerised tomography identified oesophageal varices (EVs) in 103/130 patients, and endoscopy identified EVs in 103/130 patients. Computerised tomography identified GVs in 86/130 patients, and endoscopy identified GVs in 26/130 patients. After endoscopic elastic band ligation (EBL), CT identified GVs in 22/26 patients, and endoscopy identified GVs in 7/26 patients. Conclusions Gastric varices lie in the submucosa, deeper than EVs, and distinguishing GVs from gastric rugae may be difficult with video endoscopy. This study demonstrated that CT is a sensitive method for early detection of GVs and has been used previously in the evaluation of GVs.

  20. Chemoselective ligation

    DOEpatents

    Saxon, Eliana; Bertozzi, Carolyn Ruth

    2011-12-13

    The present invention features a chemoselective ligation reaction that can be carried out under physiological conditions. In general, the invention involves condensation of a specifically engineered phosphine, which can provide for formation of an amide bond between the two reactive partners resulting in a final product comprising a phosphine moiety, or which can be engineered to comprise a cleavable linker so that a substituent of the phosphine is transferred to the azide, releasing an oxidized phosphine byproduct and producing a native amide bond in the final product. The selectivity of the reaction and its compatibility with aqueous environments provides for its application in vivo (e.g., on the cell surface or intracellularly) and in vitro (e.g., synthesis of peptides and other polymers, production of modified (e.g., labeled) amino acids).

  1. Chemoselective ligation

    DOEpatents

    Saxon, Eliana; Bertozzi, Carolyn

    2006-10-17

    The present invention features a chemoselective ligation reaction that can be carried out under physiological conditions. In general, the invention involves condensation of a specifically engineered phosphine, which can provide for formation of an amide bond between the two reactive partners resulting in a final product comprising a phosphine moiety, or which can be engineered to comprise a cleavable linker so that a substituent of the phosphine is transferred to the azide, releasing an oxidized phosphine byproduct and producing a native amide bond in the final product. The selectivity of the reaction and its compatibility with aqueous environments provides for its application in vivo (e.g., on the cell surface or intracellularly) and in vitro (e.g., synthesis of peptides and other polymers, production of modified (e.g., labeled) amino acids).

  2. Chemoselective ligation

    DOEpatents

    Saxon, Eliana; Bertozzi, Carolyn Ruth

    2010-11-23

    The present invention features a chemoselective ligation reaction that can be carried out under physiological conditions. In general, the invention involves condensation of a specifically engineered phosphine, which can provide for formation of an amide bond between the two reactive partners resulting in a final product comprising a phosphine moiety, or which can be engineered to comprise a cleavable linker so that a substituent of the phosphine is transferred to the azide, releasing an oxidized phosphine byproduct and producing a native amide bond in the final product. The selectivity of the reaction and its compatibility with aqueous environments provides for its application in vivo (e.g., on the cell surface or intracellularly) and in vitro (e.g., synthesis of peptides and other polymers, production of modified (e.g., labeled) amino acids).

  3. Chemoselective ligation

    DOEpatents

    Saxon, Eliana; Bertozzi, Carolyn

    2003-05-27

    The present invention features a chemoselective ligation reaction that can be carried out under physiological conditions. In general, the invention involves condensation of a specifically engineered phosphine, which can provide for formation of an amide bond between the two reactive partners resulting in a final product comprising a phosphine moiety, or which can be engineered to comprise a cleavable linker so that a substituent of the phosphine is transferred to the azide, releasing an oxidized phosphine byproduct and producing a native amide bond in the final product. The selectivity of the reaction and its compatibility with aqueous environments provides for its application in vivo (e.g., on the cell surface or intracellularly) and in vitro (e.g., synthesis of peptides and other polymers, production of modified (e.g., labeled) amino acids).

  4. Chemoselective ligation

    DOEpatents

    Saxon, Eliana; Bertozzi, Carolyn R.

    2010-02-23

    The present invention features a chemoselective ligation reaction that can be carried out under physiological conditions. In general, the invention involves condensation of a specifically engineered phosphine, which can provide for formation of an amide bond between the two reactive partners resulting in a final product comprising a phosphine moiety, or which can be engineered to comprise a cleavable linker so that a substituent of the phosphine is transferred to the azide, releasing an oxidized phosphine byproduct and producing a native amide bond in the final product. The selectivity of the reaction and its compatibility with aqueous environments provides for its application in vivo (e.g. on the cell surface or intracellularly) and in vitro (e.g., synthesis of peptides and other polymers, production of modified (e.g., labeled) amino acids).

  5. Chemoselective ligation

    DOEpatents

    Saxon, Eliana; Bertozzi, Carolyn R.

    2011-04-12

    The present invention features a chemoselective ligation reaction that can be carried out under physiological conditions. In general, the invention involves condensation of a specifically engineered phosphine, which can provide for formation of an amide bond between the two reactive partners resulting in a final product comprising a phosphine moiety, or which can be engineered to comprise a cleavable linker so that a substituent of the phosphine is transferred to the azide, releasing an oxidized phosphine byproduct and producing a native amide bond in the final product. The selectivity of the reaction and its compatibility with aqueous environments provides for its application in vivo (e.g., on the cell surface or intracellularly) and in vitro (e.g., synthesis of peptides and other polymers, production of modified (e.g., labeled) amino acids).

  6. Chemoselective ligation

    DOEpatents

    Saxon, Eliana; Bertozzi, Carolyn R.

    2011-05-10

    The present invention features a chemoselective ligation reaction that can be carried out under physiological conditions. In general, the invention involves condensation of a specifically engineered phosphine, which can provide for formation of an amide bond between the two reactive partners resulting in a final product comprising a phosphine moiety, or which can be engineered to comprise a cleavable linker so that a substituent of the phosphine is transferred to the azide, releasing an oxidized phosphine byproduct and producing a native amide bond in the final product. The selectivity of the reaction and its compatibility with aqueous environments provides for its application in vivo (e.g., on the cell surface or intracellularly) and in vitro (e.g., synthesis of peptides and other polymers, production of modified (e.g., labeled) amino acids).

  7. Multiple esophageal variceal ruptures with massive ascites due to myelofibrosis-induced portal hypertension

    PubMed Central

    Tokai, Koichi; Miyatani, Hiroyuki; Yoshida, Yukio; Yamada, Shigeki

    2012-01-01

    A 75-year old man had been diagnosed at 42 years of age as having polycythemia vera and had been monitored at another hospital. Progression of anemia had been recognized at about age 70, and the patient was thus referred to our center in 2008 where secondary myelofibrosis was diagnosed based on bone marrow biopsy findings. Hematemesis due to rupture of esophageal varices occurred in January and February of 2011. The bleeding was stopped by endoscopic variceal ligation. Furthermore, in March of the same year, hematemesis recurred and the patient was transported to our center. He was in irreversible hemorrhagic shock and died. The autopsy showed severe bone marrow fibrosis with mainly argyrophilic fibers, an observation consistent with myelofibrosis. The liver weighed 1856 g the spleen 1572 g, indicating marked hepatosplenomegaly. The liver and spleen both showed extramedullary hemopoiesis. Myelofibrosis is often complicated by portal hypertension and is occasionally associated with gastrointestinal hemorrhage due to esophageal varices. A patient diagnosed as having myelofibrosis needs to be screened for esophageal/gastric varices. Myelofibrosis has a poor prognosis. Therefore, it is necessary to carefully decide the therapeutic strategy in consideration of the patient’s concomitant conditions, treatment invasiveness and quality of life. PMID:22851873

  8. [Left predominance of varices: myth or reality?].

    PubMed

    Cornu-Thénard, A; Maraval, M; Boivin, P; Parpex, P

    1986-01-01

    The study of 843 legs operated for major varices shows that they are equally distributed between the two lower limbs (48.6% on the right, 51.4% on the left). There is little sex-determined variation in this distribution (410 women - 184 men), the main difference being that found in men: +4.6% on the left. Other studies carried out in Europe come to much the same conclusion. Two of these studies do, however, note a much clearer predominance of left-leg varices in men (+10%). For some studies, the lack of information about the type of varices being considered has proved troublesome (for example the many isolated telangiectasis and varices) and means that it is impossible to come to any exact conclusion. Clinical quantification is therefore desirable: at least it takes into account the diameter of the varices studied.

  9. Varices and Variceal Hemorrhage in Cirrhosis: A New View of an Old Problem.

    PubMed

    Garcia-Tsao, Guadalupe; Bosch, Jaime

    2015-11-01

    The management of portal hypertension in cirrhosis has evolved over time, leading to improvements in the care and survival of patients with varices and variceal hemorrhage, particularly in patients who achieve a significant reduction in portal pressure. In addition to better treatment strategies and improved therapeutic options, the issue of risk stratification has become essential to identify different patient subpopulations that require a different treatment. We now recognize that the management of varices and variceal hemorrhage must be taken in the context of other complications of cirrhosis (ascites, encephalopathy, jaundice) and that the goals of therapy should be based on the presence of such complications. Evolving knowledge of the predominant pathophysiological mechanisms at each of the stages of cirrhosis also has evolved and will continue to lead to improvements in therapy. This review focuses on the management of varices and variceal hemorrhage with respect to refinements in the risk stratification of patients with cirrhosis.

  10. Preventing the development of varices in cirrhosis.

    PubMed

    Garcia-Tsao, Guadalupe

    2007-01-01

    Gastroesophageal varices are a direct consequence of portal hypertension. Nonselective beta-adrenergic blockers decrease portal pressure and are effective in preventing variceal hemorrhage. However, a large multicenter placebo-controlled trial demonstrates that nonselective beta-adrenergic blockers are not effective in preventing the development of varices and are associated with a significant rate of adverse events. This therapy is, therefore, not recommended in compensated cirrhotic patients without varices at large. In this very compensated group of patients with cirrhosis (stage 1, ie, without varices and without ascites or encephalopathy) the predictive value (both for the development of varices and for the development of clinical decompensation) of a baseline hepatic venous pressure gradient greater than 10 mm Hg is confirmed, supporting this threshold level as one that defines a clinically significant portal hypertension. Importantly, reductions in hepatic venous pressure gradient >10% are associated with a significant reduction in the development of varices, a therapeutic goal that could be achieved through the use of beta-blockers or other drugs being developed for the treatment of portal hypertension.

  11. Bleeding varices: 1. Emergency management.

    PubMed Central

    Hanna, S S; Warren, W D; Galambos, J T; Millikan, W J

    1981-01-01

    The aim of the emergency management of bleeding varices is to stop the hemorrhage nonoperatively if possible, avoiding emergency shunt surgery, an operation that has a higher mortality than elective shunt surgery. Patients with an upper gastrointestinal hemorrhage should undergo endoscopy immediately to verify the diagnosis of bleeding varices. They can then be categorized according to whether they stop bleeding spontaneously (group 1), continue to bleed slowly (group 2) or continue to bleed rapidly (group 3). Group 1 patients are discussed in the second part of this two-part series. Group 2 patients are initially treated with vasopressin given intravenously; those who fail to respond should undergo emergency angiography and receive vasopressin intra-arterially. If this fails, patients at low surgical risk should undergo urgent shunt surgery; those at high risk do better with endoscopic sclerotherapy. Group 3 patients are also given an intravenous infusion of vasopressin. Patients at low surgical risk who continue to bleed then receive tamponade with a Sengstaken--Blakemore tube. If this fails, they undergo emergency creation of an H-shaped mesocaval shunt. Patients at high surgical risk who fail to respond to vasopressin given intravenously are next treated intra-arterially. If this fails they are given either endoscopic or transhepatic sclerotherapy. PMID:7006779

  12. Computed tomographic recognition of gastric varices

    SciTech Connect

    Balthazar, E.J.; Megibow, A.; Naidich, D.; LeFleur, R.S.

    1984-06-01

    The computed tomographic (CT) findings in 13 consecutive patients with proven gastric varices were analyzed and correlated with the radiographic, angiographic, and gastroscopic evaluations. In 11 patients, CT clearly identified large (five) or smaller (six) varices located mainly along the posteromedial wall of the gastric fundus and proximal body of the stomach. Well defined rounded or tubular densities that enhanced during intravenous administration of contrast material and could not be distinguished from the gastric wall were identified. Dense, enhancing, round or tubular, intraluminal filling defects were seen in the cases where the stomach was distended with water. In seven patients, the CT examination correctly diagnosed the pathogenesis of gastric varices by identifying hepatic cirrhosis, calcific pancreatis, and carcinoma of the pancreas.

  13. Scintigraphic demonstration of gastrointestinal bleeding due to mesenteric varices

    SciTech Connect

    Hansen, M.E.; Coleman, R.E. )

    1990-07-01

    Mesenteric varices can appear as massive, acute lower gastrointestinal bleeding. The small bowel or colon may be involved, varices usually developing at sites of previous surgery or inflammation in patients with portal hypertension. Two patients with alcoholic cirrhosis and protal hypertension presented with rectal bleeding. Tc-99m RBC studies demonstrated varices and extravasation into the adjacent bowel. The varices were documented by mesenteric angiography. Characteristic features of Tc-99m labeled RBC studies can identify mesenteric varices as the cause of intestinal bleeding and localize the abnormal vessels.

  14. Direct Percutaneous Embolization of Bleeding Stomal Varices

    SciTech Connect

    Naidu, Sailen G.; Castle, Erik P.; Kriegshauser, J. Scott; Huettl, Eric A.

    2010-02-15

    Stomal variceal bleeding can develop in patients with underlying cirrhosis and portal hypertension. Most patients are best treated with transjugular intrahepatic portosystemic shunt (TIPS) creation because this addresses the underlying problem of portal hypertension. However, some patients are not good candidates for TIPS creation because they have end-stage liver disease or encephalopathy. We describe such a patient who presented with recurrent bleeding stomal varices, which was successfully treated with percutaneous coil embolization. The patient had bleeding-free survival for 1 month before death from unrelated causes.

  15. Duodenal varices successfully treated with cyanoacrylate injection therapy

    PubMed Central

    Malik, Ahsan; Junglee, Naushad; Khan, Anwar; Sutton, Jonathon; Gasem, Jaber; Ahmed, Waqar

    2011-01-01

    Duodenal varices are a rare complication of portal hypertension secondary to liver cirrhosis. Compared to oesophageal varices, they bleed less often but are also more difficult to diagnose and treat. There is no established treatment for bleeding duodenal varices and different treatment strategies have been employed with variable results. The authors present a case of 52-year-old male who was admitted with melaena. Upper gastrointestinal endoscopy was performed which identified bleeding varices in the second part of duodenum. The varices were injected with cyanoacrylate and the outcome was favourable. Subsequent endoscopies showed complete resolution of the varices. The authors conclude that cyanoacrylate injection is an effective first-line treatment for bleeding duodenal varices. PMID:22694885

  16. Management of acute variceal bleeding: emphasis on endoscopic therapy.

    PubMed

    Cárdenas, Andrés

    2010-05-01

    Acute variceal bleeding is one of the most serious and feared complications of patients with portal hypertension. The most common cause of portal hypertension is advanced liver disease. Patients with esophageal and gastric varices may bleed because of a progressive increase in portal pressure that causes them to grow and finally rupture. This article will review the current management strategies for acute variceal bleeding with emphasis on endoscopic therapy for the acute episode.

  17. Noninvasive diagnosis of esophageal varices: is it feasible?

    PubMed

    de Franchis, Roberto

    2006-11-01

    The possibility of identifying cirrhotic patients with esophageal varices by noninvasive means is attractive, because it would allow for the restriction of the performance of screening endoscopy to patients at high risk of having varices. Over the years, several studies addressing this issue have been performed with little success. The recently proposed platelet count/spleen diameter ratio appears to be the best noninvasive predictor of esophageal varices developed so far. However, the available evidence is not yet sufficient to allow for the modification of the current policy of screening cirrhotic patients by endoscopy at the time of diagnosis to detect varices.

  18. Hepatic Angiosarcoma Associated with Esophageal Variceal Hemorrhage

    PubMed Central

    Ito, Zensho; Kajihara, Mikio; Kobayashi, Yasunobu; Kanai, Tomoya; Matsumoto, Yoshihiro; Takakura, Kazuki; Yukawa, Toyokazu; Ohkusa, Toshifumi; Koyama, Seita; Imazu, Hiroo; Arakawa, Hiroshi; Ohata, Mitsuru; Koido, Shigeo

    2016-01-01

    Primary hepatic angiosarcoma is a very rare malignancy with a poor prognosis. Because patients present with no specific symptoms, the cancer can grow undetected and most cases are diagnosed too late for resection. We present the case of a 78-year-old Japanese man admitted to our hospital with massive hematemesis and melena. A total gastrectomy had previously been performed on the patient to treat gastric cancer. Endoscopic injection sclerotherapy was performed to control the bleeding from varices over the anastomosis. Computed tomography revealed the presence of multiple atypical liver nodules in the enhanced image. Histological diagnosis of hepatic angiosarcoma was obtained by percutaneous ultrasound-guided liver biopsy. To our knowledge, this is the first report of a patient with hepatic angiosarcoma and acute variceal hemorrhage. PMID:27721730

  19. Tubal ligation - slideshow

    MedlinePlus

    ... anatomy URL of this page: //medlineplus.gov/ency/presentations/100044.htm Tubal ligation - Series—Normal anatomy To use the sharing features on this page, please enable JavaScript. Go to slide 1 out of 3 Go to slide 2 ...

  20. Tubal Ligation Reversal

    MedlinePlus

    ... depending on a woman's age and other factors. Success rates may be as high as 80 percent or ... details of the procedure Discuss the likelihood of success and your ability to get pregnant after the procedure Discuss other options for pregnancy, such as IVF A tubal ligation reversal can be done as ...

  1. Colonic varices demonstrated by technetium-99m red cell scintigraphy

    SciTech Connect

    Brill, D.R.

    1987-03-01

    Colonic varices is a rare condition, generally associated with portal hypertension, which normally presents as acute, severe, gastrointestinal blood loss. A case is presented in which the varicosities were observed serendipitously in a patient with a pancreatic tumor, in whom the bleeding was not variceal but due to two small unrelated gastric hemangiomas. The literature is reviewed and scintigraphic features described.

  2. Embolization of Large Gastric Varices Using Vena Cava Filter and Coils

    SciTech Connect

    Ford, Jason M.; Shah, Himanshu Stecker, Michael S.; Namyslowski, Jan

    2004-08-15

    A 40-year-old male with alcoholic cirrhosis and portal hypertension presented with acute variceal hemorrhage. Abdominal CT scan and endoscopy revealed large gastric varices. The patient underwent a TIPS procedure. Portal venography demonstrated persistent filling of the large gastric varices with associated high-flow spontaneous splenorenal shunt. Because of the large size of the varices, a Simon-Nitinol filter was used in conjunction with multiple embolization coils to enable successful occlusion of the varices.

  3. [Usefulness of branched-chain amino acid (BCAA)-enriched nutrient mixture for nutritional treatment undergoing endoscopic treatment for esophageal varices].

    PubMed

    Shibata, Naozumi; Matsui, Hidetaka; Takeshita, Eiji; Yokota, Tomoyuki; Higaki, Naoyuki; Murakami, Hidehiro; Ikeda, Yoshiou; Minami, Hisaka; Matsuura, Bunzo; Onji, Morikazu

    2005-07-01

    We investigated the alteration of nutritional status in 144 patients who were treated for the first time with endoscopic sclerotherapy or endoscopic variceal ligation during their therapies. The serum levels of albumin, cholinesterase and total cholesterol were compared before and after treatment. The serum level of cholinesterase declined significantly. To investigate the impact of aging on the changes of nutritional status we divided all patients into two groups: (1) under 65 years, and (2) over 65 years. The decline of serum albumin of elderly patients (n=65) was significantly greater than that of younger patients (n=79). A branched-chain amino acid (BCAA)-enriched nutrient mixture for nutritional treatment significantly suppressed the decline of serum albumin in elderly patients. Nutritional treatment with a BCAA-enriched nutrient mixture should be considered during endoscopic therapy for esophageal varices, especially in elderly patients.

  4. [Endoscopic ligation in treatment and prevention of bleeding from esophageal varices].

    PubMed

    Gabriel', S A; Guchetl', A Ya; Durleshter, V M; Dyn'ko, V Yu; Murashko, D S; Krushel'nitsky, V S

    2017-01-01

    Введение. Лечение осложнений портальной гипертензии является одной из актуальных, сложных и нерешенных проблем современной медицины. За последние десятилетия во всех странах мира отмечается рост числа больных циррозом печени — наиболее частой причины развития портальной гипертензии. Цель исследования — показать эффективность эндоскопического лигирования в лечении и профилактике кровотечений из ВРВП у больных циррозом печени с синдромом портальной гипертензии различной этиологии. Материал и методы. Нами проведен ретроспективный анализ результатов лечения 338 больных циррозом печени, которым выполняли лигирование за период с 2009 г. по май 2016 г. Среди больных было 209 (61,8%) мужчин и 129 (38,2%) женщин. В этой группе выполнено 511 лигирований. Общее число лигированных узлов составило 4086. Результаты и обсуждение. Лигирование было эффективным в 502 (98,2%) случаях. В 9 (1,8%) случаях эндоскопическое лигирование оказалось неэффективным и закончилось постановкой зонда Блеймора. Основной причиной неудач явилось активное кровотечение из ВРВП, развившееся до или во время лигирования. Осложнениями в рассматриваемой группе можно считать 3 случая возникновения кровотечения при попытке лигирования. Вывод. Эндоскопическое лигирование ВРВП является высокоэффективным (с экономической и медицинской точки зрения) методом лечения и профилактики кровотечения из ВРВП у больных циррозом печени.

  5. Oestrogen deficiency after tubal ligation.

    PubMed

    Cattanach, J

    1985-04-13

    4 of 7 women who had undergone tubal ligation within the past seven years were found to have oestrogen excretion concentrations at ovulation below the tenth percentile. A disturbance in the oestrogen/progesterone ratio as a consequence of localised hypertension at the ovary, when the utero-ovarian arterial loop is occluded at tubal ligation, is proposed as a possible cause of oestrogen deficiency syndrome, dysfunctional uterine bleeding, and menorrhagia after tubal ligation. Similar pathophysiology may occur after hysterectomy with ovarian conservation.

  6. The Role of Medical Therapy for Variceal Bleeding.

    PubMed

    Bhutta, Abdul Q; Garcia-Tsao, Guadalupe

    2015-07-01

    Acute variceal hemorrhage (AVH) is a lethal complication of portal hypertension and should be suspected in every patient with liver cirrhosis who presents with upper gastrointestinal bleed. AVH-related mortality has decreased in the last few decades from 40% to 15%-20% due to advances in the general and specific management of variceal hemorrhage. This review summarizes current management of AVH and prevention of recurrent hemorrhage with a focus on pharmacologic therapy.

  7. ENDOSCOPIC DIAGNOSIS AND THERAPY IN GASTRO-ESOPAGEAL VARICEAL BLEEDING

    PubMed Central

    Sanyal, Arun J.

    2016-01-01

    Gastroesophageal variceal hemorrhage is a medical emergency with high morbidity and mortality. Endoscopic therapy is the mainstay of management of bleeding varices. It requires attention to technique and the appropriate choice of therapy for a given patient at a given point in time. Subjects must be monitored continuously after initiation of therapy for control of bleeding and second line definitive therapies introduced quickly if endoscopic and pharmacologic treatment fails. PMID:26142034

  8. Massive Hemorrhage from Ectopic Duodenal Varices: Importance of a Multidisciplinary Approach

    PubMed Central

    House, Tyler; Webb, Patrick; Baarson, Chad

    2017-01-01

    Duodenal variceal bleeding is an uncommon complication of portal hypertension that can easily go unrecognized and reach mortality rates as high as 40%. Cirrhosis is the most common cause of duodenal varices. In most cases, duodenal varices occur concomitantly with esophageal varices, further complicating identification with initial endoscopy. Although many modalities have been explored with respect to management and treatment approaches, guidelines have yet to be established owing to the infrequency in which bleeding occurs from ectopic duodenal varices. We present a case of massive duodenal variceal hemorrhage that highlights the complexity of initial diagnosis and ultimately required a transesophageal intrahepatic portosystemic shunt with coil embolization for control of bleeding. PMID:28203136

  9. Safety of direct endoscopic necrosectomy in patients with gastric varices

    PubMed Central

    Storm, Andrew C; Thompson, Christopher C

    2016-01-01

    AIM: To determine the feasibility and safety of transgastric direct endoscopic necrosectomy (DEN) in patients with walled-off necrosis (WON) and gastric varices. METHODS: A single center retrospective study of consecutive DEN for WON was performed from 2012 to 2015. All DEN cases with gastric fundal varices noted on endoscopy, computed tomography (CT) or magnetic resonance imaging (MRI) during the admission for DEN were collected for analysis. In all cases, external urethral sphincter (EUS) with doppler was used to exclude the presence of intervening gastric varices or other vascular structures prior to 19 gauge fine-needle aspiration (FNA) needle access into the cavity. The tract was serially dilated to 20 mm and was entered with an endoscope for DEN. Pigtail stents were placed to facilitate drainage of the cavity. Procedure details were recorded. Comprehensive chart review was performed to evaluate for complications and WON recurrence. RESULTS: Fifteen patients who underwent DEN for WON had gastric varices at the time of their procedure. All patients had an INR < 1.5 and platelets > 50. Of these patients, 11 had splenic vein thrombosis and 2 had portal vein thrombosis. Two patients had isolated gastric varices, type 1 and the remaining 13 had > 5 mm gastric submucosal varices on imaging by CT, MRI or EUS. No procedures were terminated without completing the DEN for any reason. One patient had self-limited intraprocedural bleeding related to balloon dilation of the tract. Two patients experienced delayed bleeding at 2 and 5 d post-op respectively. One required no therapy or intervention and the other received 1 unit transfusion and had an EGD which revealed no active bleeding. Resolution rate of WON was 100% (after up to 2 additional DEN in one patient) and no patients required interventional radiology or surgical interventions. CONCLUSION: In patients with WON and gastric varices, DEN using EUS and doppler guidance may be performed safely. Successful resolution

  10. An Unusual Reason for Gastric Variceal Hemorrhage: Wandering Spleen.

    PubMed

    Köseoğlu, Hüseyin; Atalay, Roni; Büyükaşık, Naciye Şemnur; Canyiğit, Murat; Özer, Mehmet; Solakoğlu, Tevfik; Akın, Fatma Ebru; Bolat, Aylin Demirezer; Yürekli, Öykü Tayfur; Ersoy, Osman

    2015-12-01

    Wandering spleen is the displacement of the spleen due to the loss or weakening of the ligaments of the spleen and is seen very rarely with an incidence of less than 0.5 %. It can cause portal hypertension, but gastric variceal hemorrhage is a quite rare condition within the spectrum of this uncommon disease. We report a 22-year-old woman with wandering spleen presenting with life-threatening gastric variceal hemorrhage. Her diagnosis was made by computerized tomography. Endoscopic therapy was not adequate to stop the bleeding, and urgent splenectomy was performed. After surgery she has been well with no symptoms until now.

  11. Incidence of large oesophageal varices in patients with cirrhosis: application to prophylaxis of first bleeding.

    PubMed Central

    Calès, P; Desmorat, H; Vinel, J P; Caucanas, J P; Ravaud, A; Gerin, P; Brouet, P; Pascal, J P

    1990-01-01

    Because several studies have suggested that beta blockers are effective in the prophylaxis of first variceal bleeding in cirrhosis, screening for oesophageal varices might be appropriate. We prospectively studied 84 cirrhotic patients without obvious evidence of large oesophageal varices and previous bleeding during a mean follow up of 16 months. At entry to the study 41 patients had no oesophageal varices and in 43 these were grade 1. The subsequent percentages of patients without large oesophageal varices were 74% at one year and 52% at two years. Univariate analysis showed that a longer duration of cirrhosis (p less than 0.05) and grade 1 oesophageal varices at entry (p less than 0.001) were predictive factors for the occurrence of large oesophageal varices, whereas, multivariate analysis showed that the initial size of the oesophageal varices (p less than 0.001), a high initial Child-Pugh score, and a smaller improvement in Child-Pugh score during the study were independent risk factors. Among patients with grades 0 and 1 oesophageal varices at the start of the study the proportions with large oesophageal varices at two years were 31% and 70% respectively. We have calculated that, accepting a maximum risk of first bleeding of 10% without prophylactic treatment, a patient without oesophageal varices should be screened endoscopically every other year, while a patient with grade 1 disease should benefit from one annual upper gastrointestinal endoscopy. PMID:2253916

  12. [Digestive hemorrhage caused by gastric varices: usefulness of the techniques of endoscopic sclerosis].

    PubMed

    Endozain Sosa, J C; Muñoz Núñez, F; Rodríguez Blanes, J A; González Murillo, M; González García, D; Berges Magaña, M; Castillo Grau, P; Presa Valle, M; Crespo Sánchez, M

    1992-08-01

    Upper gastrointestinal hemorrhage secondary to gastric varices still has a high death rate. Fourteen patients were admitted to our unit with bleeding gastric varices from November 1989 to August 1991. Endoscopic injection sclerotherapy obtained control of the bleeding in 92.3%; however, recurrences occurred in 33% of these cases in the first 24-48 hours, with a death rate of 50% during the second stage of the upper gastrointestinal hemorrhage. Total mortality rate was 21.4%. Of the fourteen patients, nine exhibited junctional varices, while five hand fundic varices. In ten of the fourteen patients, gastric varices developed during esophageal sclerotherapy. While hospitalized, it was observed that patients with gastric varices in the fundus had more recurrences and mortality, than those located next to the cardio-esophageal junction. Sclerosis of the varices only obtained temporary control of the bleeding with greater frequency of recurrences and mortality.

  13. Laparoscopic splenectomy for a wandering spleen complicating gastric varices: report of a case.

    PubMed

    Sato, Masanori; Miyaki, Yuichiro; Tochikubo, Junpei; Onoda, Takanobu; Shiiya, Norihiko; Wada, Hidetoshi

    2015-12-01

    Wandering spleen is a rare clinical entity, and its chronic torsion of the vascular pedicle result in splenic vein occlusion leading to gastric varices. Here, we present a case of wandering spleen complicating gastric varices in a 40-year-old female. Three-dimensional CT (3D-CT) clearly showed the disruption of the splenic vein at the origin of the vascular pedicle and collateral development of the gastric varices. The patient was electively treated with laparoscopic splenectomy. Difficulty of prediction of the splenic vein recanalization to improve the varices was the reason for the use of splenectomy versus splenopexy. The varices were successfully diminished 3 months after the surgery. After review of cases of complicating gastric varices in the literatures, splenectomy is still a secure way to treat an adult patient with wandering spleen with complicating gastric varices.

  14. Factors that Determine the Development and Progression of Gastroesophageal Varices in Patients with Chronic Hepatitis C

    PubMed Central

    Fontana, Robert J.; Sanyal, Arun J.; Ghany, Marc G.; Lee, William M.; Reid, Andrea E.; Naishadham, Deepa; Everson, Gregory T.; Kahn, Jeffrey A.; Di Bisceglie, Adrian M.; Szabo, Gyongyi; Morgan, Timothy R.; Everhart, James E.

    2010-01-01

    Background & Aims We aimed to identify the incidence and predictors of de novo gastroesophageal variceal formation and progression in a large cohort of patients with chronic hepatitis C (CHC) and advanced fibrosis. Methods All participants in the HALT-C Trial were offered an endoscopy before treatment and again after 4 years. Patients with varices at baseline also had a endoscopy at 2 years. Baseline laboratory and clinical parameters were analyzed as predictors of de novo variceal formation and variceal progression. Results De novo varices developed in 157 of the 598 (26.2%) patients. Most of the new varices were small (76.4%) and only 1% of patients developed variceal hemorrhage. The likelihood of developing varices was associated with subject race (Hispanic > Caucasian > African American, p= 0.0005), lower baseline levels of albumin (P=0.051), and higher levels of hyaluronic acid (P< 0.001) with an area under the receiver operating characteristic (AUROC) curve=0.70. Among 210 patients with existing gastroesophageal varices, 74 (35.2%) had variceal progression or bleeding during follow-up. Patients with a higher baseline ratios of serum aspartate /alanine aminotransferase (P=0.028) and lower platelet counts (P=0.0002) were at greatest risk of variceal progression (AUROC = 0.72). Prolonged, low-dose peginterferon α2a therapy and β-blockers did not influence the risk of developing new or enlarging varices. Conclusion Development of varices in patients with CHC is associated with patient race/ethnicity and laboratory markers of disease severity. Prolonged low dose peginterferon α2a therapy and β-blockers do not reduce the risk of variceal development nor progression. PMID:20211180

  15. Prevention of Portal Hypertension: from Variceal Development to Clinical Decompensation

    PubMed Central

    Vorobioff, Julio D.; Groszmann, Roberto J

    2015-01-01

    Pharmacological treatment of portal hypertension (PH) has been exclusively devoted to gastro-esophageal varices related events at different frameworks including prophylactic, emergency or preventive therapy. The goals of treatment are to avoid the first bleeding episode, stop active bleeding and prevent bleeding recurrence, respectively. The objective of pre-primary prophylaxis (PPP) is to avoid variceal development and therefore, it necessarily deals with cirrhotic patients at earlier stages of the disease. At these earlier stages, nonselective beta blocker (NSBB) have been ineffective in preventing the development of varices and other complications of PH. Therefore, treatment should not rely on NSBB. It is possible, that at these earlier stages, etiological treatment of liver disease itself could prevent the progression of PH. This review will focus mainly on early treatment of PH, because if successful, it may translate into histological-hemodynamic improvements, avoiding not only variceal development but also other PH related complications, such as ascites and porto-systemic encephalopathy (PSE). Moreover, the advent of new therapies may allow not only the prevention of the complications of PH, but also the chance of a substantial degree of regression in the cirrhotic process with the possible prevention of hepatocellular carcinoma (HCC). PMID:24913395

  16. Bleeding Duodenal: Varices Treatment by TIPS and Transcatheter Embolization

    SciTech Connect

    Lopera, Jorge E. Arthurs, Blain; Scheuerman, Christian; Sandoz, Charles; Petersosn, Scott; Castaneda-Zuniga, Wildriodo

    2008-03-15

    We describe our clinical experience in 4 patients with portal hypertension who presented with bleeding mesenteric varices originating from the superior mesenteric vein with retrograde filling of collaterals draining into the inferior vena cava. The clinical presentation, imaging findings, and potential therapeutic management are discussed.

  17. Vulvar varices: an uncommon entity in surgical pathology.

    PubMed

    Bell, Diana; Kane, Philip B; Liang, Sharon; Conway, Christine; Tornos, Carmen

    2007-01-01

    Varicose veins in the vulvar and perivulvar area are seen in 4% of women. Most of them are secondary to pregnancy and usually regress spontaneously. Vulvar varicose veins are rare in nonpregnant women. When present, they can be seen alone, associated with leg varices or associated with venous malformations of the labia, clitoral area, or vagina with or without arteriovenous malformations on the limbs or trunk (Klippel-Trenaunay-Weber syndrome and Parkes-Weber syndrome). In some cases, vulvar varices are seen as part of the so-called "pelvic congestion syndrome." Clinically, vulvar varices may present as small isolated protrusions, mainly in the labia majora, or as large masses, involving the vulva and even the perivulvar area. The treatment of choice of vulvar varices seen during pregnancy is conservative and symptomatic. Surgical pathologists need to be aware of the existence of vulvar varicose veins and its possible presence in biopsy specimens. Vulvar varicose veins can be misdiagnosed clinically as cysts or masses mainly in the Bartholin gland area. Correct diagnosis of the lesion is important to determine appropriate therapy and to recognize the possibility of associated anatomical or pathological problems.

  18. [Post-tubal ligation syndrome].

    PubMed

    Satoh, K; Osada, H

    1993-01-01

    Post-tubal ligation syndrome includes pain during intercourse, aching lower back, premenstrual tension syndrome, difficulty in menstruating, uterine hemorrhage, and absence of menstruation. The syndrome is caused by blood circulation problems in and around the Fallopian tubes and ovaries, pressure on nerves, and intrapelvic adhesion. Differentiating between this syndrome and endometritis during diagnosis and differentiating between functional hemorrhage due to hormonal abnormality and anatomical hemorrhage due to polyp or tumor is very important. Since the symptoms of this syndrome are mild, simple symptomatic treatment is sufficient in most cases. In some cases, however, desquamation surgery or reversal of tubal ligation may be necessary. Endoscopic surgery is also available. In Japan, because of widespread use of condoms and IUDs, tubal ligation is not very common.

  19. Results of treatment of esophageal variceal hemorrhage with endoscopic injection of n-butyl-2-cyanoacrylate in patients with Child-Pugh class C cirrhosis

    PubMed Central

    Ribeiro, Joao Paulo; Matuguma, Sérgio Eiji; Cheng, Spencer; Herman, Paulo; Sakai, Paulo; D'Albuquerque, Luiz Augusto Carneiro; Maluf-Filho, Fauze

    2015-01-01

    Background and study aims: The results of endoscopic treatment with elastic band ligation for esophageal variceal bleeding in patients with Child-Pugh class C cirrhosis remain poor. In comparison with treatment with elastic band ligation, we have found lower rates of rebleeding and mortality with n-butyl-2-cyanoacrylate injections. Thus, the aim of the current study was to describe our unit’s 10 years of experience with injection of n-butyl-2-cyanoacrylate to control esophageal variceal ruptures in patients with Child-Pugh class C cirrhosis. Patients and methods: A single-center, retrospective study was conducted. Sixty-three patients with Child-Pugh class C cirrhosis had been admitted to the center with an acute episode of esophageal variceal bleeding. All were treated with injection of n-butyl-2-cyanoacrylate. The patients were assigned to 1 of 2 groups according to their Child-Pugh class C cirrhosis scores: group I (score range, 10 through 13 points) and group II (score, 14 or 15 points). The 3 variables studied were rates of initial failure to control bleeding, failure to prevent rebleeding (secondary prophylaxis), and mortality. Patients in the 2 groups (group I, n = 50; group II, n = 13) had similar characteristics. Results: Bleeding was successfully controlled in almost 75 % of the patients during the first 5 days after treatment, with no significant differences observed between groups I and II. There were no significant differences between the 2 groups with respect to mortality rate for the first 5 days after treatment. Thirty-four patients (54 %) were free of bleeding at 6 weeks after treatment, with a significant difference noted between the groups: group I, 64 %, versus group II, 15.4 % (P < 0.001). The overall mortality rate was 44.4 %, with a significant difference noted between the groups: group I, 34 %, versus group II, 84.6 % (P < 0.001). Conclusion: Endoscopic injection of n-butyl-2-cyanoacrylate is a valid treatment

  20. Bleeding due to ectopic varices in a urinary diversion: A multidisciplinary diagnostic and therapeutic challenge

    PubMed Central

    Acosta, Eduardo Mariano Albers; Reyes, Alfonsi Friera; Menéndez, Ricardo Brime

    2015-01-01

    The ectopic varices in patients with portal hypertension are those that occur at any level of the gastrointestinal (GI) tract, regardless of the varices that occur at the esophageal level. These ectopic varices account for 2–5% of the causes of GI bleeding varices. The risk of bleeding is quadrupled compared to the esophagogastric area, with a mortality of up to 40%. The transjugular intrahepatic portosystemic shunt, should be considered in cases secondary to recurrent bleeding varices. We present a case report of an urological emergency of bleeding in a urinary diversion secondary to ectopic varices successfully treated through the placement of transjugular intrahepatic portosystemic shunt. The condition described here is rare, but important, as it can be a life-threatening complication of portal hypertension. This kind of complication should be known by urologic surgeons managing patients with urinary diversions. PMID:26834901

  1. Balloon-Occluded Retrograde Transvenous Obliteration for Gastric Varices: A Feasibility Study

    SciTech Connect

    Sonomura, Tetsuo; Sato, Morio; Kishi, Kazushi; Terada, Masaki; Shioyama, Yasukazu; Kimura, Masashi; Suzuki, Kenzo; Kutsukake, Yasumichi; Ushimi, Takashi; Tanaka, Junji; Hayashi, Seishu; Tanaka, Satoshi

    1998-01-15

    Purpose: To evaluate the clinical feasibility of balloon-occluded retrograde transvenous obliteration (BORTO) for gastric varices. Methods: BORTO was performed in 14 patients with gastric varices due to liver cirrhosis. The gastric varices were confirmed by endoscopy, and their feeding and draining veins were identified by contrast-enhanced computed tomography (CT) and angiography. A 6 Fr Simmons-shaped balloon catheter was inserted into the gastrorenal shunt. The balloon was inflated, and 5% ethanolamine oleate iopamidol was infused slowly through the catheter. Patients were followed up with endoscopy and enhanced CT at 1 week, 1, 3, and 6 months after the procedure and every 6 months thereafter. Results: The gastric varices completely disappeared in 12 of 14 patients and was partially resolved in the remaining 2 patients. Neither a recurrence nor an aggravation of gastric varices were found. No major complications were experienced. Conclusion: BORTO is a safe and effective treatment for gastric varices.

  2. Invasive and noninvasive methods to diagnose portal hypertension and esophageal varices.

    PubMed

    de Franchis, Roberto; Dell'Era, Alessandra

    2014-05-01

    Assessing the presence of clinically significant portal hypertension and esophageal varices is clinically important in cirrhosis. The reference standard techniques to assess the presence of portal hypertension and varices are the measurement of the hepatic vein pressure gradient and esophagogastroduodenoscopy, respectively. Some newer methods have shown a good performance, but none has been proven precise enough to replace hepatic vein pressure gradient measurement or esophagogastroduodenoscopy for the diagnosis of portal hypertension or the presence and grade of esophageal varices.

  3. Percutaneous Retrograde Sclerotherapy for Refractory Bleeding of Jejunal Varices: Direct Injection via Superficial Epigastric Vein

    SciTech Connect

    Nakata, Manabu Nakata, Waka; Isoda, Norio Yoshizawa, Mitsuyo; Sugimoto, Hideharu

    2012-02-15

    Small-bowel varices are rare and almost always occur in cases with portal hypertension. We encountered a patient with bleeding jejunal varices due to liver cirrhosis. Percutaneous retrograde sclerotherapy was performed via the superficial epigastric vein. Melena disappeared immediately after treatment. Disappearance of jejunal varices was confirmed by contrast-enhanced computed tomography. After 24 months of follow-up, no recurrent melena was observed.

  4. Septic Complication After Balloon-Occluded Retrograde Transvenous Obliteration of Duodenal Variceal Bleeding

    SciTech Connect

    Akasaka, Thai; Shibata, Toshiya Isoda, Hiroyoshi; Taura, Kojiro; Arizono, Shigeki; Shimada, Kotaro; Togashi, Kaori

    2010-12-15

    We report a 64-year-old woman with duodenal varices who underwent balloon-occluded retrograde transvenous obliteration (B-RTO) complicated by intraprocedural variceal rupture. The patient developed shivering and a fever higher than 40{sup o}C 3 days after the B-RTO procedure. A blood culture grew Entereobacter cloacoe. This case represents a rare septic complication of B-RTO for duodenal varices.

  5. [Surgical Removal of Migrated Coil after Embolization of Jejunal Variceal Bleeding: A Case Report].

    PubMed

    Kim, Junhwan; Lee, Danbi; Oh, Kyunghwan; Lee, Mingee; So, Seol; Yang, Dong Hoon; Kim, Chan Wook; Gwon, Dong Il; Chung, Young Hwa

    2017-01-25

    Jejunal variceal bleeding is less common compared with esophagogastric varices in patients with portal hypertension. However, jejunal variceal bleeding can be fatal without treatment. Treatments include surgery, transjugular intrahepatic porto-systemic shunt (TIPS), endoscopic sclerotherapy, percutaneous coil embolization, and balloon-occluded retrograde transvenous obliteration (BRTO). Percutaneous coil embolization can be considered as an alternative treatment option for those where endoscopic sclerotherapy, surgery, TIPS or BRTO are not possible. Complications of percutaneous coil embolization have been reported, including coil migration. Herein, we report a case of migration of the coil into the jejunal lumen after percutaneous coil embolization for jejunal variceal bleeding. The migrated coil was successfully removed using surgery.

  6. Oesophageal and gastric varices: historical aspects, classification and grading: everything in one place

    PubMed Central

    Abby Philips, Cyriac; Sahney, Amrish

    2016-01-01

    Variceal disease and its management are of the utmost importance in the treatment of portal hypertension. Current guidelines are universal for management of variceal disease in portal hypertension. Classification and grading systems are numerous and differ according to geographical location. In this exhaustive review, the historical aspects of variceal disease, its classification and the grading systems in use are discussed, with self-explanatory tables and timelines. A better and clear understanding of the evolution of portal hypertension and variceal disease is provided. PMID:27324725

  7. Application of Balloon-Occluded Retrograde Transvenous Obliteration to Gastric Varices Complicating Refractory Ascites

    SciTech Connect

    Fukuda, Tetsuya; Hirota, Shozo; Matsumoto, Shinichi; Sugimoto, Koji; Fujii, Masahiko; Tsurusaki, Masakatsu; Izaki, Kenta; Sugimura, Kazuro

    2004-01-15

    We report two cases of gastric varices complicated by massive ascites that disappeared after balloon-occluded retrograde transvenous obliteration (B-RTO). The first patient had progressive gastric varices that continued to enlarge even after three episodes of esophagogastric variceal bleeding, and the second patient was admitted to our hospital because of the bleeding from gastric varices. After B-RTO procedures in both patients, significant improvement of the ascites, hepatic function reserve, and hypoalbuminemia was observed. Although further experience is needed, our experience points to the likelihood of the amelioration of ascites after B-RTO.

  8. The postal tubal ligation syndrome.

    PubMed

    Faber, E; Rocko, J M; Timmes, J J; Zolli, A F

    1981-01-01

    The frequency of symptoms following tubal ligation calls for an examination of the basic problem with the methods now used. This discussion recommends a modification of tubal ligation which as performed during the past 2-1/2 years has been symptom free, post operatively. What is meant by symptom free is those symptoms which can be directly related to tubal ligation. Symptomatology is complex and insidious. Characteristically, there is a latent period of no symptoms. This asymptomatic period may be totally subjective and may last several years during which time the correlation between surgery and symptoms is obscured. This is particularly the case if purely symptomatic therapeusis has had some degree of success. The latest period is followed by the gradual development of the following: menstrual disorders; abdominal pain which is usually located in the lower abdomen and is of 2 varieties, i.e., dysmenorrhea and nonmenstrual pain; and infection. Physical examination demonstrates little. This set of symptoms, which has been documented also by Poma et al., and when taken as a whole, constitutes a syndrome which should be termed the posttubal ligation syndrome. These patients give a history of repeat X-rays, biopsies, endoscopies, and surgical exploration. Some of these patients have had 4 or 5 celiotomies. A modification of the traditional method of tubal ligation definitely requires consideration. The characteristics of the oviducts which need mention and emphasis are reviewed. On the basis of the reviewed considerations, it becomes obvious that smooth transport of the ovum is a necessity and that obstruction in the tubes will cause a reaction similar to obstruction anywhere in the body. Tubal ligation should be performed in such a manner so as not to obstruct the ova from passing down the tube. The tubes should be cut fairly close to the uterus and be tied. The rest of the tube from fimbria to the isthmus should be left open. In this manner, the ovum passes into the

  9. Bleeding oesophageal varices with long term follow up.

    PubMed Central

    Spence, R A; Johnston, G W; Odling-Smee, G W; Rodgers, H W

    1984-01-01

    Complete long term follow up was obtained in 27 children who had bled from oesophageal varices. Most presented with haematemesis or melaena at an average age of 5.2 years in the portal vein thrombosis group (20 children) and 9.5 years in the intrahepatic group (7 children). All had splenomegaly. Only 6 of 20 children with portal vein thrombosis had a possible precipitating factor. A total of 182 admissions for bleeding are reported, in 68 of which injection sclerotherapy was used to control bleeding. Control rate with injection sclerotherapy was 97%. Shunts performed below age 10 years were associated with a high thrombosis rate. A conservative approach to bleeding varices in children is recommended with transfusion, pitressin, and injection sclerotherapy. Oesophageal transection may have a role in the emergency management of the few children in whom bleeding is not controlled by injection sclerotherapy. PMID:6609683

  10. Transcatheter Embolotherapy with N-Butyl Cyanoacrylate for Ectopic Varices

    SciTech Connect

    Choi, Jin Woo; Kim, Hyo-Cheol Jae, Hwan Jun Jung, Hyun-Seok; Hur, Saebeom; Lee, Myungsu; Chung, Jin Wook

    2015-04-15

    PurposeTo address technical feasibility and clinical outcome of transcatheter embolotherapy with N-butyl cyanoacrylate (NBCA) for bleeding ectopic varices.MethodsThe institutional review board approved this retrospective study and waived informed consent. From January 2004 to June 2013, a total of 12 consecutive patients received transcatheter embolotherapy using NBCA for bleeding ectopic varices in our institute. Clinical and radiologic features of the endovascular procedures were comprehensively reviewed.ResultsPreprocedural computed tomography images revealed ectopic varices in the jejunum (n = 7), stoma (n = 2), rectum (n = 2), and duodenum (n = 1). The 12 procedures consisted of solitary embolotherapy (n = 8) and embolotherapy with portal decompression (main portal vein stenting in 3, transjugular intrahepatic portosystemic shunt in 1). With regard to vascular access, percutaneous transhepatic access (n = 7), transsplenic access (n = 4), and transjugular intrahepatic portosystemic shunt tract (n = 1) were used. There was no failure in either the embolotherapy or the vascular accesses (technical success rate, 100 %). Two patients died within 1 month from the procedure from preexisting fatal medical conditions. Only one patient, with a large varix that had been partially embolized by using coils and NBCA, underwent rebleeding 5.5 months after the procedure. The patient was retreated with NBCA and did not undergo any bleeding afterward for a follow-up period of 2.5 months. The remaining nine patients did not experience rebleeding during the follow-up periods (range 1.5–33.2 months).ConclusionTranscatheter embolotherapy using NBCA can be a useful option for bleeding ectopic varices.

  11. Pneumatic dilation for achalasia in a patient with esophageal varices

    PubMed Central

    Désilets, Etienne; Belle, Arthur; Boustière, Christian; Laquière, Arthur

    2016-01-01

    Background and study aims: Previous reports of simultaneous presence of esophageal varices (EV) and achalasia suggest placement of a transjugular intrahepatic portosystemic shunt (TIPS) and surgical myotomy or endoscopic therapy. We report the case of a 64-year-old man who received anticoagulant therapy for a myeloproliferative disorder with extensive portal thrombosis which was a contraindication to placement of a TIPS.  PMID:27092328

  12. [Latex ligation in treatment of chronic hemorrhoids].

    PubMed

    Ektov, V N; Somov, K A

    2015-01-01

    We analyzed the results of treatment of 432 patients with chronic hemorrhoids using different variants of latex ligation. New technique including ligation of mucosa and submucosa of low-ampullar rectum providing ligation of hemorrhoidalvessels, lifting and recto-anal repair is developed and suggested. This method is advisable to use in case of chronic internal hemorrhoids stages I and II. The authors recommend simultaneous combined ligation of mucosa of low-ampullar rectum and internal hemorrhoids for stages III and IV. Different variants of latex ligation with external hemorrhoids excision were used in 103 patients. Pointed variants of latex ligation preserve important advantages including mini-invasiveness, simplicity and wide availability, low cost. Good remote results were obtained after these procedures in 87.3% of observations. Suggested tactics extends use of latex ligation and increases its effectiveness in treatment of different stages and forms of chronic hemorrhoids.

  13. Non-invasive (and minimally invasive) diagnosis of oesophageal varices.

    PubMed

    de Franchis, Roberto

    2008-10-01

    Current guidelines recommend screening all cirrhotic patients by endoscopy, to identify patients at risk of bleeding who should undergo prophylactic treatment. However, since the prevalence of varices in cirrhotic patients is variable, universal screening would imply a large number of unnecessary endoscopies and a heavy burden for endoscopy units. In addition, compliance to screening programs may be hampered by the perceived unpleasantness of endoscopy. Predicting the presence of oesophageal varices by non-invasive means might increase compliance and would permit to restrict the performance of endoscopy to those patients with a high probability of having varices. Over the years, several studies have addressed this issue by assessing the potential of biochemical, clinical and ultrasound parameters, transient elastography, CT scanning and video capsule endoscopy. The platelet count/spleen diameter ratio, CT scanning and video capsule endoscopy have shown promising performance characteristics, although none of them is equivalent to EGD. These methods are perceived by patients as preferable to endoscopy and thus might increase adherence to screening programs. Whether this will compensate for the lower sensitivity of these alternative techniques, and ultimately improve the outcomes if more patients undergo screening, is the crucial question that will have to be answered in the future.

  14. Successful Treatment of Mesenteric Varices After Living Donor Liver Transplantation with Retrograde Transvenous Obliteration Via an Abdominal Wall Vein

    SciTech Connect

    Ikeda, Osamu Tamura, Yoshitaka; Nakasone, Yutaka; Yamashita, Yasuyuki; Okajima, Hideaki; Asonuma, Katsuhiro; Inomata, Yukihiro

    2010-06-15

    Balloon-occluded retrograde transvenous obliteration is an established treatment for gastric varices; it has been used more rarely to treat mesenteric varices. We report a 12-year-old girl who had received a living donor liver transplant and suffered melena due to ruptured mesenteric varices. We addressed treatment of the mesenteric varices by retrograde transvenous obliteration of an abdominal wall collateral vein detected by superior mesenteric arteriography.

  15. Historical overview and review of current day treatment in the management of acute variceal haemorrhage

    PubMed Central

    Rajoriya, Neil; Tripathi, Dhiraj

    2014-01-01

    Variceal haemorrhage is one of the most devastating consequences of portal hypertension, with a 1-year mortality of 40%. With the passage of time, acute management strategies have developed with improved survival. The major historical treatment landmarks in the management of variceal haemorrhage can be divided into surgical, medical, endoscopic and radiological breakthroughs. We sought to provide a historical overview of the management of variceal haemorrhage and how treatment modalities over time have impacted on clinical outcomes. A PubMed search of the following terms: portal hypertension, variceal haemorrhage, gastric varices, oesophageal varices, transjugular intrahepatic portosystemic shunt was performed. To complement this, Google™ was searched with the aforementioned terms. Other relevant references were identified after review of the reference lists of articles. The review of therapeutic advances was conducted divided into pre-1970s, 1970/80s, 1990s, 2000-2010 and post-2010. Also, a summary and review on the pathophysiology of portal hypertension and clinical outcomes in variceal haemorrhage was performed. Aided by the development of endoscopic therapies, medication and improved radiological interventions; the management of variceal haemorrhage has changed over recent decades with improved survival from an often-terminating event in recent past. PMID:24914369

  16. UK guidelines on the management of variceal haemorrhage in cirrhotic patients

    PubMed Central

    Tripathi, Dhiraj; Stanley, Adrian J; Hayes, Peter C; Patch, David; Millson, Charles; Mehrzad, Homoyon; Austin, Andrew; Ferguson, James W; Olliff, Simon P; Hudson, Mark; Christie, John M

    2015-01-01

    These updated guidelines on the management of variceal haemorrhage have been commissioned by the Clinical Services and Standards Committee (CSSC) of the British Society of Gastroenterology (BSG) under the auspices of the liver section of the BSG. The original guidelines which this document supersedes were written in 2000 and have undergone extensive revision by 13 members of the Guidelines Development Group (GDG). The GDG comprises elected members of the BSG liver section, representation from British Association for the Study of the Liver (BASL) and Liver QuEST, a nursing representative and a patient representative. The quality of evidence and grading of recommendations was appraised using the AGREE II tool. The nature of variceal haemorrhage in cirrhotic patients with its complex range of complications makes rigid guidelines inappropriate. These guidelines deal specifically with the management of varices in patients with cirrhosis under the following subheadings: (1) primary prophylaxis; (2) acute variceal haemorrhage; (3) secondary prophylaxis of variceal haemorrhage; and (4) gastric varices. They are not designed to deal with (1) the management of the underlying liver disease; (2) the management of variceal haemorrhage in children; or (3) variceal haemorrhage from other aetiological conditions. PMID:25887380

  17. Bleeding oesophageal varices associated with anabolic steroid use in an athlete.

    PubMed Central

    Winwood, P. J.; Robertson, D. A.; Wright, R.

    1990-01-01

    A 30 year old bodybuilder who had been taking anabolic steroids for 18 months presented with bleeding oesophageal varices. Serious liver disease secondary to anabolic steroids including peliosis hepatis, nodular hyperplasia and malignant change is well recognized. We report what is, to our knowledge, the first case of bleeding oesophageal varices associated with the use of anabolic steroids. PMID:2099434

  18. How we manage variceal hemorrhage in cirrhotic patients. Key practical messages from the British Guidelines.

    PubMed

    Quraishi, Mohammed N; Khan, Faisal; Tripathi, Dhiraj

    2016-01-01

    Variceal bleeding is a serious complication of portal hypertension with high morbidity and mortality. Advances in our understanding of screening and risk stratification along with evidence-based management strategies for acute variceal bleeding as well as primary and secondary prevention have improved overall outcomes in patients with portal hypertension. The guidelines recently published by the British Society of Gastroenterology (BSG) and Baveno 6 consensus have aimed to enhance the standard of care in the management of varices and their complications. This concise review focuses on the key practical messages for screening and management of varices and variceal bleeding in light of these guidelines. The review also takes into account important evidence published since the BSG guidelines and Baveno 6 consensus.

  19. Percutaneous Trans-hepatic Obliteration for Bleeding Esophagojejunal Varices After Total Gastrectomy and Esophagojejunostomy

    SciTech Connect

    Boku, Michiko; Sugimoto, Koji; Nakamura, Tetsu; Kita, Yasufumi; Zamora, Carlos A. Sugimura, Kazuro

    2006-12-15

    A 72-year-old man who had undergone a total gastrectomy with a Roux-en-Y esophagojejunostomy for gastric cancer 6 years earlier presented to our hospital with massive hematemesis and melena. Endoscopic examination indicated esophageal varices with cherry-red spots and hemorrhage arising from beyond the anastomosis. Abdominal contrast-enhanced computed tomography and angiography revealed a dilated vein in the elevated jejunal limb supplying the varices. Percutaneous trans-hepatic obliteration (PTO) of the varices through the jejunal vein was performed using microcoils, ethanolamine oleate, and gelatin sponge cubes. Ten days after the procedure, endoscopic examination revealed reduction and thrombosis of the varices. We consider PTO to be an effective alternative method for treating ruptured esophagojejunal varices after total gastrectomy.

  20. Medical expenses in treating acute esophageal variceal bleeding

    PubMed Central

    Liu, Chueh-Ling; Wu, Cheng-Kun; Shi, Hon-Yi; Tai, Wei-Chen; Liang, Chih-Ming; Yang, Shih-Cheng; Wu, Keng-Liang; Chiu, Yi-Chun; Chuah, Seng-Kee

    2016-01-01

    Abstract Acute variceal bleeding in patients with cirrhosis is related to high mortality and medical expenses. The purpose of present studies was to analyze the medical expenses in treating acute esophageal variceal bleeding among patients with cirrhosis and potential influencing clinical factors. A total of 151,863 patients with cirrhosis with International Classification of Diseases-9 codes 456.0 and 456.20 were analyzed from the Taiwan National Health Insurance Research Database from January 1, 1996 to December 31, 2010. Time intervals were divided into three phases for analysis as T1 (1996–2000), T2 (2001–2005), and T3 (2006–2010). The endpoints were prevalence, length of hospital stay, medical expenses, and mortality rate. Our results showed that more patients were <65 years (75.6%) and of male sex (78.5%). Patients were mostly from teaching hospitals (90.8%) with high hospital volume (50.9%) and high doctor service load (51.1%). The prevalence of acute esophageal variceal bleeding and mean length of hospital stay decreased over the years (P < 0.001), but the overall medical expenses increased (P < 0.001). Multiple regression analysis showed that older age, female sex, Charlson comorbidity index (CCI) score >1, patients from teaching hospitals, and medium to high or very high patient numbers were independent factors for longer hospital stay and higher medical expenses. Aged patients, female sex, increased CCI score, and low doctor service volume were independent factors for both in-hospital and 5-year mortality. Patients from teaching hospitals and medium to high or very high service volume hospitals were independent factors for in-hospital mortality, but not 5-year mortality. Medical expenses in treating acute esophageal variceal bleeding increased despite the decreased prevalence rate and length of hospital stay in Taiwan. Aged patients, female sex, patients with increased CCI score from teaching hospitals, and medium to high or very high

  1. Determinants of tubal ligation in Puebla, Mexico.

    PubMed

    Rudzik, Alanna E F; Leonard, Susan H; Sievert, Lynnette L

    2011-06-21

    Tubal ligation provides an effective and reliable method by which women can choose to limit the number of children they will bear. However, because of the irreversibility of the procedure and other potential disadvantages, it is important to understand factors associated with women's choice of this method of birth control. Between May 1999 and August 2000, data were collected from 755 women aged 40 to 60 years from a cross-section of neighborhoods of varying socio-economic make-up in Puebla, Mexico, finding a tubal ligation rate of 42.2%. Multiple logistic regression models were utilized to examine demographic, socio-economic, and reproductive history characteristics in relation to women's choice of tubal ligation. Regression analyses were repeated with participants grouped by age to determine how the timing of availability of tubal ligation related to the decision to undergo the procedure. The results of this study suggest that younger age, more education, use of some forms of birth control, and increased parity were associated with women's decisions to undergo tubal ligation. The statistically significant difference of greater tubal ligation and lower hysterectomy rates across age groups reflect increased access to tubal ligation in Mexico from the early 1970s, supporting the idea that women's choice of tubal ligation was related to access.

  2. [Formation of compressive bandage after sclerotherapy for lower limb varices].

    PubMed

    Zatonskikh, B Ia; Banas, N B

    2003-01-01

    Invention concerns compressive sclerotherapy as a treatment modality for lower limb varices. Technical result of investigation is the development of compressive bandage that creates and maintains adequate level of limb compression both in supine position (during bed rest) and standing or walking. Technical result is achieved by formation of two compressive layers of elastic bandage. Highly expansible elastic bandage is used for the first layer aimed for fixation and compression of latex or foam pads at injection sites to create local compression of variceal nodes. Open toe elastic stocking (I compression class) is placed over the bandage to maintain adequate compression during bed rest. The second external layer consists of elastic bandage with moderate expansion (II compression class). It is placed over the first one from toes to thigh upper third and creates optimal compression in patient's vertical position. The patient is permitted to take it off or loose exclusively in supine position, to wash or refresh foot with wet towel, to change it with a new one.

  3. Treatment of symptomatic pelvic varices by ovarian vein embolization

    SciTech Connect

    Capasso, Patrizio; Simons, Christine; Trotteur, Genevieve; Dondelinger, Robert F.; Henroteaux, Denis; Gaspard, Ulysse

    1997-03-15

    Purpose. Pelvic congestion syndrome is a common cause of chronic pelvic pain in women and its association with venous congestion has been described in the literature. We evaluated the potential benefits of lumboovarian vein embolization in the treatment of lower abdominal pain in patients presenting with pelvic varicosities. Methods. Nineteen patients were treated. There were 13 unilateral embolizations, 6 initial bilateral treatments and 5 treated recurrences (a total of 30 procedures). All embolizations were performed with either enbucrilate and/or macrocoils, and there was an average clinical and Doppler duplex follow-up of 15.4 months. Results. The initial technical success rate was 96.7%. There were no immediate or long-term complications. Variable symptomatic relief was observed in 73.7% of cases with complete responses in 57.9%. All 8 patients who had partial or no pain relief complained of dyspareunia. The direct relationship between varices and chronic pelvic pain was difficult to ascertain in a significant number of clinical failures. Conclusion. Transcatheter embolization of lumboovarian varices is a safe technique offering symptomatic relief of pelvic pain in the majority of cases. The presence of dyspareunia seemed to be a poor prognostic factor, indicating that other causes of pelvic pain may coexist with pelvic varicosities.

  4. Diagnosis and therapy of non-variceal upper gastrointestinal bleeding

    PubMed Central

    Biecker, Erwin

    2015-01-01

    Non-variceal upper gastrointestinal bleeding (UGIB) is defined as bleeding proximal to the ligament of Treitz in the absence of oesophageal, gastric or duodenal varices. The clinical presentation varies according to the intensity of bleeding from occult bleeding to melena or haematemesis and haemorrhagic shock. Causes of UGIB are peptic ulcers, Mallory-Weiss lesions, erosive gastritis, reflux oesophagitis, Dieulafoy lesions or angiodysplasia. After admission to the hospital a structured approach to the patient with acute UGIB that includes haemodynamic resuscitation and stabilization as well as pre-endoscopic risk stratification has to be done. Endoscopy offers not only the localisation of the bleeding site but also a variety of therapeutic measures like injection therapy, thermocoagulation or endoclips. Endoscopic therapy is facilitated by acid suppression with proton pump inhibitor (PPI) therapy. These drugs are highly effective but the best route of application (oral vs intravenous) and the adequate dosage are still subjects of discussion. Patients with ulcer disease are tested for Helicobacter pylori and eradication therapy should be given if it is present. Non-steroidal anti-inflammatory drugs have to be discontinued if possible. If discontinuation is not possible, cyclooxygenase-2 inhibitors in combination with PPI have the lowest bleeding risk but the incidence of cardiovascular events is increased. PMID:26558151

  5. Duodenal variceal bleed: an unusual cause of upper gastrointestinal bleed and a difficult diagnosis to make

    PubMed Central

    Bhagani, Shradha; Winters, Conchubhair; Moreea, Sulleman

    2017-01-01

    We present a case of recurrent upper gastrointestinal (GI) bleeding in a man aged 57 years with primary biliary cholangitis who was ultimately diagnosed with an isolated duodenal variceal bleed, which was successfully treated with histoacryl glue injection. Duodenal varices are an uncommon presentation of portal hypertension and can result in significant GI bleeding with a high mortality. Diagnosis can be difficult and therapeutic options limited. Endoscopic variceal sclerotherapy with histoacryl glue provides an effective treatment, though endoscopists need to remain aware of and vigilant for the serious complications of this treatment option. PMID:28242804

  6. Cloning of DNA fragments: ligation reactions in agarose gel.

    PubMed

    Furtado, Agnelo

    2014-01-01

    Ligation reactions to ligate a desired DNA fragment into a vector can be challenging to beginners and especially if the amount of the insert is limiting. Although additives known as crowding agents, such as PEG 8000, added to the ligation mixes can increase the success one has with ligation reactions, in practice the amount of insert used in the ligation can determine the success or the failure of the ligation reaction. The method described here, which uses insert DNA in gel slice added directly into the ligation reaction, has two benefits: (a) using agarose as the crowding agent and (b) reducing steps of insert purification. The use of rapid ligation buffer and incubation of the ligation reaction at room temperature greatly increase the efficiency of the ligation reaction even for blunt-ended ligation.

  7. Wandering spleen as a cause of mesenteric and portal varices: a new etiology?

    PubMed

    Zarroug, Abdalla E; Hashim, Yassar; El-Youssef, Mounif; Zeidan, Moiz M; Moir, Christopher R

    2013-03-01

    Wandering spleen is a rare clinical entity characterized by spleen hypermobility due to lack or weakness of one or more splenic ligaments. We report two patients with the diagnosis of wandering spleen with portal and mesenteric varices. A 16 year-old girl presented with abdominal pain, an abdominal mass and pancytopenia. A 12 year-old girl presented with an abdominal mass only. Imaging studies revealed both patients had a viable but torsed wandering spleen in association with portal, splenic and mesenteric varices. Both were treated with splenectomy and had resolution of their symptoms. Imaging confirmed complete resolution of all varices at 30 month and 11 year follow up respectively. These cases represent the first report of a wandering spleen causing portal and mesenteric venous partial obstruction leading to varices; splenectomy resolved these findings post-operatively.

  8. Portal vein stent placement with or without varix embolization of jejunal variceal bleeding after hepatopancreatobiliary surgery.

    PubMed

    Shim, Dong Jae; Shin, Ji Hoon; Ko, Gi-Young; Kim, Yook; Han, Kichang; Gwon, Dong-Il; Ko, Heung-Kyu

    2017-04-01

    Background Extrahepatic portal hypertension after surgery involving the duodenum or jejunum might result in massive ectopic variceal bleeding. Purpose To report the results of portal vein stent placement with the addition of variceal embolization. Material and Methods Between January 2000 and June 2015, portal vein stent placement was attempted in 477 patients. Of these, 22 patients (age, 63 ± 10 years) with jejunal variceal bleeding caused by portal vein obstruction after surgery were included in this study. Computed tomography (CT) findings before and after treatment and the rates of technical and clinical success, complications, and clinical outcomes were retrospectively evaluated. Results Stent placement was successful in 19 of 22 patients. Additional variceal embolization was performed in five cases. Clinical success, defined as the cessation of bleeding without recurrence within 1 month, was achieved in 18 of 19 patients with technical success. One patient developed recurrent bleeding 4 days after stent placement and was successfully treated with additional variceal embolization. There were no procedure-related complications. A regression of the jejunal varices was noted in 14 of 19 patients on follow-up CT scans. During the follow-up period (258 days; range, 7-1196 days), stent occlusion and recurrent bleeding occurred in six and four patients, respectively, of the 19 patients who achieved technical success. Statistical analyses revealed no significant differences regarding stent patency between benign and malignant strictures. Conclusion Percutaneous, transhepatic, portal vein stent placement with or without jejunal variceal embolization appears to be a safe and effective treatment for jejunal variceal bleeding after surgery.

  9. Heterotopic Pregnancy Following Reversal of Tubal Ligation.

    PubMed

    Eschenbach, Stephanie; Entzian, Dirk; Baumgarten, Deborah A

    2008-01-01

    We describe the case of a 37-year-old woman who had undergone reversal of tubal ligation with subsequent heterotopic pregnancy. We review the initial radiological evaluation of heterotopic pregnancies and the subsequent radiologic findings following appropriate therapy.

  10. The correlation between cytopenia and esophageal varices in patients with liver cirrhosis.

    PubMed

    Gue, C S; Yap, C K; Ng, H S

    2004-12-01

    This retrospective study analysed the case records of 200 patients in the Department of Gastroenterology, Singapore General Hospital from February 2000 to January 2001 who had liver cirrhosis and underwent gastroscopy for the detection of varices. The aim of this study was to determine any relationship between leucopenia, thrombocytopenia and the occurrence of esophageal varices in a cirrhotic population. Our results showed that the diagnostic yield of varices grade 2 and 3 was 6.3% if platelet count was > 150,000/mm3, 25% if platelet count was 100,000 to 150,000/mm3, 38.9% if platelet count was 50,000-99,000/mm3 and 100% if platelet count was <50,000/mm3. Similarly, the diagnostic yield of varices grade 2 and 3 was 19.4% if total white count was > 4,000/mm3, 66.7% if total white count was 3,000- 4,000/mm3 and 94.8% if total white count was < 3,000/mm5. We conclude that thrombocytopenia and leucopenia can be used to stratify risk for occurrence of esophageal varices in cirrhotic patients and gastroscopy will have a high yield for varices when platelet count is < 150,000/mm3 or total white is < 4,000/mm.

  11. Clinical Results of the Transjugular Intrahepatic Portosystemic Shunt (TIPS) for the Treatment of Variceal Bleeding

    PubMed Central

    Han, Sang-Woo; Joo, Young-Eun; Kim, Hyun-Soo; Choi, Sung-Kyu; Rew, Jong-Sun; Kim, Jae-Kyu; Kim, Sei-Jong

    2000-01-01

    Background Transjugular intrahepatic portosystemic shunt (TIPS) has been popularized for the treatment of refractory variceal bleeding. The aim of this study was to assess the safety and long-term effect of TIPS in the treatment of variceal bleeding that is not controlled with pharmacological and endoscopic treatment. Methods Thirty-six patients who underwent transjugular intrahepatic portosystemic shunt (TIPS) due to refractory variceal bleeding were included in the study. The effectiveness of portal decompression and bleeding control was evaluated. Upper gastrointestinal endoscopy was performed to analyse the degree of varices and portal hypertensive gastropathy (PHG) before TIPS procedure and one to three weeks after TIPS. Angiography was performed in surviving patients, if bleeding recurred, or if ultrasonography or endoscopy suggested stent dysfunction. Results TIPS were successfully placed in 36 of 38 patients (94.6%). TIPS achieved hemostasis of variceal bleeding in 34 patients (94.4%). Portal venous pressure decreased from an initial average of 28.7±7.9 to 23.2±9.4 mmHg after TIPS (p < 0.05). The portosystemic pressure gradient was significantly decreased from 15.5±6.3 to 7.8±4.1 mmHg (p < 0.01). The degree of esophagogastric varices and PHG was significantly improved after TIPS. The total length of follow-up was from one day to 54 months (mean: 355 days). The actuarial probability of survival was 83% at one year and 74% at two years. Overall, 16 episodes of stent dysfunction were diagnosed during follow-up. Stent revision by means of angioplasty was successfully performed in 14 of these episodes. Conclusion TIPS is an effective and reliable nonoperative means of lowering portal pressure. This procedure has proved useful in the management of acute variceal bleeding refractory to endoscopic treatment. Surveillance by ultrasonography, endoscopy, and angiographic intervention is useful for the maintenance of shunt patency. PMID:11242805

  12. Partial Splenic Embolization has Beneficial Effects for the Management of Gastroesophageal Variceal Hemorrhage

    PubMed Central

    Wang, Ping; Liu, Ruibo; Tong, Liquan; Zhang, Yangjing; Yue, Tongyun; Qiao, Haiquan; Zhang, Feng; Sun, Xueying

    2016-01-01

    Background/Aims: Partial splenic embolization (PSE) is used in the management of gastroesophageal variceal hemorrhage (GEVH). However, it is uncertain whether it has beneficial effects for GEVH patients in preventing variceal recurrence and variceal hemorrhage, as well as promoting overall survival (OS), when it is combined with conventional therapies. Materials and Methods: The databases including PubMed, EMBASE, Web of Science, Google scholar, and Cochrane Central Register of Controlled Trials were searched up to 11th of November, 2015. Meta-analyses were performed by using Review Manager 5.3 software for analyzing the risk of bias, Newcastle-Ottawa Scale for assessing the bias of cohort studies, and GRADEprofiler software for assessing outcomes obtained from the meta-analyses. Results: A total of 1505 articles were reviewed, and 1 randomized controlled trial and 5 cohort studies with 244 participants were eligible for inclusion. The pooled hazard ratio (HR) of variceal recurrence is 0.50 (95% confidence interval (CI) 0.37, 0.68; P< 0.00001; I2 = 0%). The pooled HR of variceal hemorrhage is 0.24 (95% CI 0.15, 0.39; P< 0.00001; I2 = 0%). The pooled HR of OS is 0.50 (95% CI 0.33, 0.67; P< 0.00001; I2 = 0%). Meta-analyses demonstrated statistically significant superiority of combinational therapies over conventional therapies in preventing variceal recurrence and variceal hemorrhage and prolonging OS. The complications related to PSE were mild or moderate and nonfatal. Conclusions: The results indicate that PSE has beneficial effects for GEVH patients, however, future investigation with a larger number of subjects in clinical trials is warranted. PMID:27976634

  13. Bleeding Duodenal Varices Successfully Treated with Balloon-Occluded Retrograde Transvenous Obliteration (B-RTO) Assisted by CT During Arterial Portography

    SciTech Connect

    Tsurusaki, Masakatsu Sugimoto, Koji; Matsumoto, Shinichi; Izaki, Kenta; Fukuda, Tetsuya; Akasaka, Yoshinobu; Fujii, Masahiko; Hirota, Shozo; Sugimura, Kazuro

    2006-12-15

    A 60-year-old woman with massive hemorrhage from duodenal varices was transferred to our hospital for the purpose of transcatheter intervention. Although digital subtraction arterial portography could not depict the entire pathway of collateral circulation, the efferent route of the duodenal varices was clearly demonstrated on subsequent CT during arterial portography. Balloon-occluded retrograde transvenous obliteration (B-RTO) of the varices was performed via the efferent vein and achieved complete thrombosis of the varices.

  14. Transjugular intrahepatic portosystemic shunt for the management of acute variceal hemorrhage

    PubMed Central

    Loffroy, Romaric; Estivalet, Louis; Cherblanc, Violaine; Favelier, Sylvain; Pottecher, Pierre; Hamza, Samia; Minello, Anne; Hillon, Patrick; Thouant, Pierre; Lefevre, Pierre-Henri; Krausé, Denis; Cercueil, Jean-Pierre

    2013-01-01

    Acute variceal hemorrhage, a life-threatening condition that requires a multidisciplinary approach for effective therapy, is defined as visible bleeding from an esophageal or gastric varix at the time of endoscopy, the presence of large esophageal varices with recent stigmata of bleeding, or fresh blood visible in the stomach with no other source of bleeding identified. Transfusion of blood products, pharmacological treatments and early endoscopic therapy are often effective; however, if primary hemostasis cannot be obtained or if uncontrollable early rebleeding occurs, transjugular intrahepatic portosystemic shunt (TIPS) is recommended as rescue treatment. The TIPS represents a major advance in the treatment of complications of portal hypertension. Acute variceal hemorrhage that is poorly controlled with endoscopic therapy is generally well controlled with TIPS, which has a 90% to 100% success rate. However, TIPS is associated with a mortality of 30% to 50% in such a setting. Emergency TIPS should be considered early in patients with refractory variceal bleeding once medical treatment and endoscopic sclerotherapy failure, before the clinical condition worsens. Furthermore, admission to specialized centers is mandatory in such a setting and regional protocols are essential to be organized effectively. This review article discusses initial management and then focuses on the specific role of TIPS as a primary therapy to control acute variceal hemorrhage, particularly as a rescue therapy following failure of endoscopic approaches. PMID:24115809

  15. Torque expression in self-ligating orthodontic brackets and conventionally ligated brackets: A systematic review

    PubMed Central

    Al-Thomali, Yousef; Mohamed, Roshan-Noor; Basha, Sakeenabi

    2017-01-01

    Background To evaluate the torque expression of self ligating (SL) orthodontic brackets and conventionally ligated brackets and the torque expression in active and passive SL brackets. Material and Methods Our systematic search included MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus, and key journals and review articles; the date of the last search was April 4th 2016. We graded the methodological quality of the studies by means of the Quality Assessment Tool for Quantitative Studies, developed for the Effective Public Health Practice Project (EPHPP). Results In total, 87 studies were identified for screening, and 9 studies were eligible. The quality assessment rated one of the study as being of strong quality, 7 (77.78%) of these studies as being of moderate quality. Three out of 7 studies which compared SL and conventionally ligated brackets showed, conventionally ligated brackets with highest torque expression compared to SL brackets. Badawi showed active SL brackets with highest torque expression compared to passive SL brackets. Major and Brauchli showed no significant differences in torque expression of active and passive SL brackets. Conclusions Conventionally ligated brackets presented with highest torque expression compared to SL brackets. Minor difference was recorded in a torque expression of active and passive SL brackets. Key words:Systematic review, self ligation, torque expression, conventional ligation. PMID:28149476

  16. The Role of Spleen Stiffness in Determining the Severity and Bleeding Risk of Esophageal Varices in Cirrhotic Patients

    PubMed Central

    Kim, Hwi Young; Jin, Eun Hyo; Kim, Won; Lee, Jae Young; Woo, Hyunsik; Oh, Sohee; Seo, Ji-Yeon; Oh, Hong Sang; Chung, Kwang Hyun; Jung, Yong Jin; Kim, Donghee; Kim, Byeong Gwan; Lee, Kook Lae

    2015-01-01

    Abstract Esophageal varix and its hemorrhage are serious complications of liver cirrhosis. Recent studies have focused on noninvasive prediction of esophageal varices. We attempted to evaluate the association of liver and spleen stiffness (LS and SS) as measured by acoustic radiation force impulse imaging, with the presence and severity of esophageal varices and variceal hemorrhage in cirrhotic patients. We measured LS and SS, along with endoscopic examination of esophageal varices for a total of 125 cirrhotic patients at a single referral hospital in this prospective observational study. The diagnostic utility of noninvasive methods for identifying varices and their bleeding risk was compared, including LS, SS, spleen length, Child-Pugh score, and various serum fibrosis indices. Esophageal varices were present in 77 patients (61.6%). SS was significantly higher in patients with varices than in those without varices (3.58 ± 0.47 vs 3.02 ± 0.49; P < 0.001). A tendency toward increasing SS levels was observed with increasing severity of varices (no varix, 3.02 ± 0.49; F1, 3.39 ± 0.51; F2, 3.60 ± 0.42; F3, 3.85 ± 0.37; P < 0.001). SS was significantly higher in patients who experienced variceal hemorrhage than in those who did not (3.80 ± 0.36 vs 3.20 ± 0.51; P = 0.002). An optimal cut-off value of SS for high-risk varices (≥F2) or variceal hemorrhage was 3.40 m/s. SS was significantly correlated with the presence, severity, and bleeding risk of esophageal varices. Prompt endoscopic evaluation of variceal status and prophylactic measures based on the SS may be warranted for cirrhotic patients. PMID:26091449

  17. Respiratory function after injection sclerotherapy of oesophageal varices.

    PubMed Central

    Samuels, T; Lovett, M C; Campbell, I T; Makin, C; Davies, J; Jenkins, S A; Baxter, J N

    1994-01-01

    Arterial oxygen tension (Pao2), carbon dioxide tension (PaCO2), and vital capacity were measured preoperatively and one day postoperatively in patients with chronic hepatic cirrhosis having elective oesophageal injection sclerotherapy under general anaesthesia. The results were compared with the same measurements made in patients with chronic cirrhosis anaesthetised and scheduled to have injection sclerotherapy under general anaesthesia but who, because of variceal obliteration, only had an oesophagogastroscopy. In the injected group PaO2 decreased by 9.3 (3.0) mm Hg (1.2 (0.4) kPa) (mean (SEM)) (p < 0.02) but in the controls did not change. The difference between the two groups was significant (p < 0.02). Vital capacity decreased by 0.39 (0.08) litres (BTPS) (p < 0.01) after injection sclerotherapy but in the controls did not change. Again the difference between the two groups was significant (p < 0.02). In the injected group there was a significant correlation between the change in PaO2 and the percentage change in vital capacity (r = 0.787, p < 0.01) but no such relation was seen in control subjects. These results suggest that oesophageal injection sclerotherapy is associated with a restrictive defect in respiratory function one day after the injection caused, possibly, by sclerosant embolising to the lung. PMID:7959205

  18. Tracheal varices caused by mediastinal compression of a large intrathoracic goiter: report of a case

    PubMed Central

    LUCCHINI, R.; SANTOPRETE, S.; TRIOLA, R.; POLISTENA, A.; MONACELLI, M.; AVENIA, S.; SANGUINETTI, A.; PUMA, F.; AVENIA, N.

    2015-01-01

    Introduction Tracheal varices are a rare condition but they can be an important source of massive or recurrent haemoptysis. Usually they are related to increased pressure in the pulmonary veins. Mediastinal goiter is often associated to compressive effects on the surrounding structures, including mediastinal vessels with potential superior vena cava syndrome. Case report We describe a case, not previously reported in literature, of mediastinal goiter with hemoptysis as first clinical manifestation. Bleeding was attributed to a superior vena cava syndrome associated to a tracheal fragile mucosa with an easily bleeding intramural nodule which was diagnosed as tracheal varices after total thyroidectomy. The nodule in fact disappeared together with the venous hypertensive signs after venous decompression of the mediastinum. Conclusions Compressive symptoms including tracheal varices, related to mediastinal goiter, can be treated surgically by total thyroidectomy via cervicotomy and when required with associated median sternotomy. PMID:25827666

  19. A case of torsion of the wandering spleen presenting as hypersplenism and gastric fundal varices.

    PubMed

    Irak, Kader; Esen, Irfan; Keskın, Murat; Emınler, Ahmet Tarık; Ayyildiz, Talat; Kaya, Ekrem; Kiyici, Murat; Gürel, Selim; Nak, Selim Giray; Gülten, Macit; Dolar, Enver

    2011-02-01

    Wandering spleen is the displacement of the spleen from its normal location due to the loss or weakening of ligaments that hold the spleen in the left upper quadrant. The possibility of torsion of the spleen is high due to the long and mobile nature of the vascular pedicle. Generally, cases are asymptomatic. Under conditions of delayed diagnosis, symptoms of splenomegaly, left portal hypertension, gastric fundal varices, and hypersplenism may present as a result of development of vascular congestion associated with chronic torsion. There are only a few cases in the literature reporting the association of wandering spleen and fundal varices. We report herein the case of a 55-year-old female who admitted to our clinic with complaints of fatigue and epigastric pain. She was determined to have gastric fundal varices and hypersplenism secondary to the development of left portal hypertension due to chronic splenic torsion.

  20. Predictors of a variceal source among patients presenting with upper gastrointestinal bleeding

    PubMed Central

    Alharbi, Ahmad; Almadi, Majid; Barkun, Alan; Martel, Myriam

    2012-01-01

    BACKGROUND: Patients with upper gastrointestinal bleeding (UGIB) require an early, tailored approach best guided by knowledge of the bleeding lesion, especially a variceal versus a nonvariceal source. OBJECTIVE: To identify, by investigating a large national registry, variables that would be predictive of a variceal origin of UGIB using clinical parameters before endoscopic evaluation. METHODS: A retrospective study was conducted in 21 Canadian hospitals during the period from January 2004 until the end of May 2005. Consecutive charts for hospitalized patients with a primary or secondary discharge diagnosis of UGIB were reviewed. Data regarding demographics, including historical, physical examination, initial laboratory investigations, endoscopic and pharmacological therapies administered, as well as clinical outcomes, were collected. Multivariable logistic regression modelling was performed to identify clinical predictors of a variceal source of bleeding. RESULTS: The patient population included 2020 patients (mean [± SD] age 66.3±16.4 years; 38.4% female). Overall, 215 (10.6%) were found to be bleeding from upper gastrointestinal varices. Among 26 patient characteristics, variables predicting a variceal source of bleeding included history of liver disease (OR 6.36 [95% CI 3.59 to 11.3]), excessive alcohol use (OR 2.28 [95% CI 1.37 to 3.77]), hematemesis (OR 2.65 [95% CI 1.61 to 4.36]), hematochezia (OR 3.02 [95% CI 1.46 to 6.22]) and stigmata of chronic liver disease (OR 2.49 [95% CI 1.46 to 4.25]). Patients treated with antithrombotic therapy were more likely to experience other causes of hemorrhage (OR 0.44 [95% CI 0.35 to 0.78]). CONCLUSION: Presenting historical and physical examination data, and initial laboratory tests carry significant predictive ability in discriminating variceal versus nonvariceal sources of bleeding. PMID:22506257

  1. Ectopic Varices in the Gastrointestinal Tract: Short- and Long-Term Outcomes of Percutaneous Therapy

    SciTech Connect

    Macedo, Thanila A. Andrews, James C.; Kamath, Patrick S.

    2005-04-15

    To evaluate the results of percutaneous management of ectopic varices, a retrospective review was carried out of 14 patients (9 men, 5 women; mean age 58 years) who between 1992 and 2001 underwent interventional radiological techniques for management of bleeding ectopic varices. A history of prior abdominal surgery was present in 12 of 14 patients. The interval between the surgery and percutaneous intervention ranged from 2 to 38 years. Transhepatic portal venography confirmed ectopic varices to be the source of portal hypertension-related gastrointestinal bleeding. Embolization of the ectopic varices was performed by a transhepatic approach with coil embolization of the veins draining into the ectopic varices. Transjugular intrahepatic portosystemic shunt (TIPS) was performed in the standard fashion. Eighteen procedures (12 primary coil embolizations, 1 primary TIPS, 2 re-embolizations, 3 secondary TIPS) were performed in 13 patients. One patient was not a candidate for percutaneous treatment. All interventions but one (re-embolization) were technically successful. In 2 of 18 interventions, re-bleeding occurred within 72 hr (both embolization patients). Recurrent bleeding (23 days to 27 months after initial intervention) was identified in 9 procedures (8 coil embolizations, 1 TIPS due to biliary fistula). One patient had TIPS revision because of ultrasound surveillance findings. New encephalopathy developed in 2 of 4 TIPS patients. Percutaneous coil embolization is a simple and safe treatment for bleeding ectopic varices; however, recurrent bleeding is frequent and reintervention often required. TIPS can offer good control of bleeding at the expense of a more complex procedure and associated risk of encephalopathy.

  2. The frequency and influence of gallbladder varices on gallbladder functions in patients with portal hypertension.

    PubMed

    Chawla, A; Dewan, R; Sarin, S K

    1995-11-01

    Gallbladder varices have been reported in patients with portal hypertension. The exact frequency and significance of these collaterals in patients with cirrhotic and noncirrhotic portal hypertension is not known. One hundred and two patients with portal hypertension [38 with cirrhosis, 29 with noncirrhotic portal fibrosis (NCPF) and 35 with extrahepatic portal vein obstruction (EHPVO)] and 25 healthy controls were studied. Gallbladder varices were seen at ultrasound as tortuous, dilated vessels in the wall or in the bed of the gallbladder. In 35 patients (19 patients with and 16 without gallbladder varices) and in 10 healthy controls, gallbladder functions were studied by determining fasting volume (FV) and then residual volume (RV) every 10 min over 1 h after giving a liquid meal of 420 k.cal. Ejection fraction (EF) was computed as a percentage by the formula: FV--RV/FV x 100. Twenty four (24%) patients had gallbladder varices: Five (13%) with cirrhosis, seven (24%) with NCPF, and 12 (34%) with EHPVO. FV in EHPVO patients was seen significantly more than in cirrhotics (31.6 +/- 15.4 vs 19.3 +/- 6.0 ml, p < 0.05). The RV and EF were not different in the three groups of patients compared with the controls. The EF was similar in patients with or without gallbladder varices (63.3 +/- 10.2% vs 64.6 +/- 10.4%). Gallbladder varices are often seen in portal hypertension, more often in EHPVO patients, and these collaterals cause some gallbladder stasis but do not impede gallbladder function and hence seem unlikely to contribute to gallstone formation.

  3. Antiviral therapy delays esophageal variceal bleeding in hepatitis B virus-related cirrhosis

    PubMed Central

    Li, Chang-Zheng; Cheng, Liu-Fang; Li, Qing-Shan; Wang, Zhi-Qiang; Yan, Jun-Hong

    2013-01-01

    AIM: To investigate the effect of antiviral therapy with nucleoside analogs in hepatitis B virus (HBV)-related cirrhosis and esophageal varices. METHODS: Eligible patients with HBV-related cirrhosis and esophageal varices who consulted two tertiary hospitals in Beijing, China, the Chinese Second Artillery General Hospital and Chinese PLA General Hospital, were enrolled in the study from January 2005 to December 2009. Of 117 patients, 79 received treatment with different nucleoside analogs and 38 served as controls. Bleeding rate, change in variceal grade and non-bleeding duration were analyzed. Multivariate Cox proportional hazard regression was used to identify factors related to esophageal variceal bleeding. RESULTS: The bleeding rate was decreased in the antiviral group compared to the control group (29.1% vs 65.8%, P < 0.001). Antiviral therapy was an independent factor related to esophageal bleeding in multivariate analysis (HR = 11.3, P < 0.001). The mean increase in variceal grade per year was lower in the antiviral group (1.0 ± 1.3 vs 1.7 ± 1.2, P = 0.003). Non-bleeding duration in the antiviral group was prolonged in the Kaplan-Meier model. Viral load rebound was observed in 3 cases in the lamivudine group and in 1 case in the adefovir group, all of whom experienced bleeding. Entecavir and adefovir resulted in lower bleeding rates (17.2% and 28.6%, respectively) than the control (P < 0.001 and P = 0.006, respectively), whereas lamivudine (53.3%) did not (P = 0.531). CONCLUSION: Antiviral therapy delays the progression of esophageal varices and reduces bleeding risk in HBV-related cirrhosis, however, high-resistance agents tend to be ineffective for long-term treatment. PMID:24187460

  4. Post tubal ligation syndrome or iatrogenic hydrosalpinx.

    PubMed

    Gregory, M G

    1981-10-01

    The purpose of this case report is as follows: to attempt to establish an association between the observed increase in hydrosalpinx and the phenomenal increase in surgical sterilization; to present a credible etiology for iatrogenic hydrosalpinx; and to discuss the pathogenesis of a disease process henceforth referred to as post tubal ligation syndrome. A 36-year-old white woman was admitted to Park View Hospital in Nashville, Tennessee on January 7, 1981 for evaluation of continuous lower abdominal pain, abdominal pressure, and dyspareunia for several months. The woman had 2 children who were delivered vaginally. An abdominal tubal ligation was performed for sterilization when she was 27, and vaginal hysterectomy, with anterior and posterior colporrhaphy, was done for symptomatic pelvic relaxation at age 33. Physical examination showed tenderness without palpable masses in the pelvic adnexal areas. Laboratory studies were within normal limits. On January 9, 1981, the patient underwent exploratory laparotomy, and bilateral salpingo-oophorectomy. She was found to have bilateral hydrosalpinx. Historically, hydrosalpinx has been considered an intermediary step in pelvic inflammatory disease. Iatrogenic hydrosalpinx is, in essence, initiated by an initial insult, e.g., tubal ligation, fulguration, or application of a mechanical clip or band. Theoretically, single point interruption of a fallopian tube should produce no ill effects. The popularity and success of tubal ligation attest to single point interruption of an otherwise normal fallopian tube as an innocuous procedure. A schematic drawing is provided of the same tube insulted a 2nd time and consequently the situation is prefactory to development of hydrosalpinx, i.e., a tube lined with secretory epithelium is closed at both ends. Secretion within this closed system will produce dilatation. This "2nd" insult to the normal fallopian tube, post tubal ligation, may take 1 of several forms. The symptoms of iatrogenic

  5. Systemic Mastocytosis as an Unconventional Cause of Variceal Bleeding: Think Outside the Box

    PubMed Central

    Kesavan, Mayurathan; Jilani, Basmah N; Ahmed, Saba; Deeb, Liliane

    2016-01-01

    Systemic mastocytosis is a rare infiltrative disease involving the skin, bone marrow, digestive system, and liver. We report a case of a 59-year-old male who presented with a massive variceal bleed without any evidence of cirrhosis; however was later found to have severe perisinusoidal fibrosis with mast cells in portal tracts on liver biopsy and hypercellular mast cell infiltrated bone marrow. This rare case describes an out-of-the-ordinary reason of variceal bleeding with preserved liver function due to non-cirrhotic portal hypertension.   PMID:27433408

  6. Peristomal variceal bleeding treated by coil embolization using a percutaneous transhepatic approach

    PubMed Central

    Maciel, Macello José Sampaio; Pereira, Osvaldo Ignácio; Motta Leal Filho, Joaquim Maurício; Ziemiecki Junior, Enio; Cosme, Susyanne Lavor; Souza, Moisés Amâncio; Carnevale, Francisco Cesar

    2016-01-01

    Peristomal variceal bleeding due to portal hypertension is an entity that has rarely been reported with 3%-4% risk of death. A 68-year-old woman who had undergone a palliative colostomy (colorectal carcinoma) presented with a massive hemorrhage from the colostomy conduit. Considering her oncological status with medial and right hepatic veins thrombosis due to liver metastasis invasion, an emergency transhepatic coil embolization was successfully performed. Standard treatment modality for these cases has not been established. Percutaneous transhepatic coil embolization of varices is a safe and effective choice in patients who present with life threatening bleeding and exhibit contraindications to transjugular intrahepatic portosystemic shunt. PMID:26798628

  7. Peristomal variceal bleeding treated by coil embolization using a percutaneous transhepatic approach.

    PubMed

    Maciel, Macello José Sampaio; Pereira, Osvaldo Ignácio; Motta Leal Filho, Joaquim Maurício; Ziemiecki Junior, Enio; Cosme, Susyanne Lavor; Souza, Moisés Amâncio; Carnevale, Francisco Cesar

    2016-01-16

    Peristomal variceal bleeding due to portal hypertension is an entity that has rarely been reported with 3%-4% risk of death. A 68-year-old woman who had undergone a palliative colostomy (colorectal carcinoma) presented with a massive hemorrhage from the colostomy conduit. Considering her oncological status with medial and right hepatic veins thrombosis due to liver metastasis invasion, an emergency transhepatic coil embolization was successfully performed. Standard treatment modality for these cases has not been established. Percutaneous transhepatic coil embolization of varices is a safe and effective choice in patients who present with life threatening bleeding and exhibit contraindications to transjugular intrahepatic portosystemic shunt.

  8. Utility of endoscopic ultrasound in the diagnosis and management of esophagogastric varices

    PubMed Central

    Wang, An-Jiang; Li, Bi-Min; Zheng, Xue-Lian; Shu, Xu; Zhu, Xuan

    2016-01-01

    Endoscopic ultrasound (EUS) has significantly improved our understanding of the complex vascular structural changes in patients with portal hypertension. At present, EUS is a useful diagnostic tool for the evaluation of esophagogastric varices (EGVs) and guidance of endoscopic therapy. Several studies have employed this new technique for the diagnosis and management of esophageal and gastric varices, respectively. In the present review, we have summarized the current status of EUS for the diagnosis and management of EGVs and clarified the clinical feasibility of this procedure. New indications for EUS can be developed in the future after adequate validation. PMID:27503152

  9. Diagnostic non-invasive model of large risky esophageal varices in cirrhotic hepatitis C virus patients

    PubMed Central

    Elalfy, Hatem; Elsherbiny, Walid; Abdel Rahman, Ashraf; Elhammady, Dina; Shaltout, Shaker Wagih; Elsamanoudy, Ayman Z; El Deek, Bassem

    2016-01-01

    AIM To build a diagnostic non-invasive model for screening of large varices in cirrhotic hepatitis C virus (HCV) patients. METHODS This study was conducted on 124 post-HCV cirrhotic patients presenting to the clinics of the Endemic Medicine Department at Mansoura University Hospital for evaluation before HCV antiviral therapy: 78 were Child A and 46 were Child B (score ≤ 8). Inclusion criteria for patients enrolled in this study was presence of cirrhotic HCV (diagnosed by either biopsy or fulfillment of clinical basis). Exclusion criteria consisted of patients with other etiologies of liver cirrhosis, e.g., hepatitis B virus and patients with high MELD score on transplant list. All patients were subjected to full medical record, full basic investigations, endoscopy, and computed tomography (CT), and then divided into groups with no varices, small varices, or large risky varices. In addition, values of Fibrosis-4 score (FIB-4), aminotransferase-to-platelet ratio index (APRI), and platelet count/splenic diameter ratio (PC/SD) were also calculated. RESULTS Detection of large varies is a multi-factorial process, affected by many variables. Choosing binary logistic regression, dependent factors were either large or small varices while independent factors included CT variables such coronary vein diameter, portal vein (PV) diameter, lieno-renal shunt and other laboratory non-invasive variables namely FIB-4, APRI, and platelet count/splenic diameter. Receiver operating characteristic (ROC) curve was plotted to determine the accuracy of non-invasive parameters for predicting the presence of large esophageal varices and the area under the ROC curve for each one of these parameters was obtained. A model was established and the best model for prediction of large risky esophageal varices used both PC/SD and PV diameter (75% accuracy), while the logistic model equation was shown to be (PV diameter × -0.256) plus (PC/SD × -0.006) plus (8.155). Values nearing 2 or more denote

  10. Pitfalls in histoacryl glue injection therapy for oesophageal, gastric and ectopic varices: A review

    PubMed Central

    Al-Hillawi, Lulia; Wong, Terence; Tritto, Giovanni; Berry, Philip A

    2016-01-01

    Histoacryl glue is used increasingly for the treatment of gastric and ectopic varices, and there is experience in its use for oesophageal varices. It is an effective treatment, yet numerous reports of complications have accumulated. This review of the literature describes the technique, explores circulatory and vascular consideration unique to portal hypertension and categorises the complications into: “Embolisation”, “local venous thrombosis”, “fistulisation and extravascular injection”, “ulceration, erosion and extrusion”, and “nidus of infection”. A case is then made for standardisation of the technique and the consent process. PMID:27933134

  11. Platelet Count to Spleen Diameter Ratio for the Diagnosis of Gastroesophageal Varices in Liver Cirrhosis: A Systematic Review and Meta-Analysis

    PubMed Central

    Chen, Runhua; Deng, Han; Xie, Chune; Wang, Wei

    2017-01-01

    Platelet count to spleen diameter ratio (PSR) was studied extensively as a noninvasive method of diagnosis for varices. The present study aimed to systematically assess the performance of PSR in the diagnosis of varices. PubMed, EMBASE, and article references were searched. The summary receiver operating characteristic curves (AUSROCs), sensitivities, specificities, positive and negative likelihood ratio, and diagnostic odds ratio were calculated. The heterogeneity, quality, and publication bias of studies were evaluated. Subgroup and sensitivity analyses were performed. A total of 49 papers were included. The AUSROCs of PSR for any varices and high-risk varices were 0.8719 and 0.8132, respectively. The summary sensitivities of PSR for any varices and high-risk varices were 0.84 and 0.78, respectively. The summary specificities of PSR for any varices and high-risk varices were 0.78 and 0.67, respectively. The AUSROC of PSR for any varices at the threshold of 909 was 0.8867. The AUSROC of PSR for any varices in viral liver cirrhosis was 0.8675. The overall quality of studies was moderate. Significant heterogeneity and publication bias existed in the study. In conclusion, PSR can be used to identify varices in liver cirrhosis. PSR had a high sensitivity in viral liver cirrhosis. PMID:28270848

  12. Neurodevelopmental Outcomes Following Two Different Treatment Approaches (Early Ligation versus Selective Ligation) for Patent Ductus Arteriosus

    PubMed Central

    Wickremasinghe, Andrea C.; Rogers, Elizabeth E.; Piecuch, Robert E.; Johnson, Bridget C.; Golden, Suzanne; Moon-Grady, Anita J.; Clyman, Ronald I.

    2012-01-01

    Objective To examine whether a change in the approach to management of persistent patent ductus arteriosus (PDA), from “early ligation” to “selective ligation,” is associated with an increased risk of abnormal neurodevelopmental outcome. Study design In 2005, we changed our PDA treatment protocol (in infants ≤27 6/7 weeks gestation) from an “early ligation” approach, with PDA ligation quickly if they failed to close after indomethacin (Period 1: 1/99–12/04), to a “selective ligation” approach, with PDA ligation only if specific criteria were met (Period 2: 1/05–5/09). All infants in both periods received prophylactic indomethacin. Multivariate analysis was used to compare the odds of a composite Abnormal Neurodevelopmental Outcome (Bayley MDI or Cognitive score <70, cerebral palsy, blindness, and/or deafness) associated with each treatment approach at 18–36 months (n=224). Results During Period 1, 23% of the infants in follow-up failed indomethacin treatment, and all were ligated; during Period 2, 30% of infants failed indomethacin, and 66% were ligated after meeting pre-specified criteria. Infants treated with the “selective ligation” strategy had fewer Abnormal Outcomes than infants treated with the “early ligation” approach (OR=0.07, p=0.046). Infants ligated before 10 days of age had an increased incidence of Abnormal Neurodevelopmental Outcome. The significant difference in outcomes between the two PDA treatment strategies could be accounted for, in part, by the earlier age of ligation during Period 1. Conclusions A “selective ligation” approach for PDAs that fail to close with indomethacin does not worsen neurodevelopmental outcome at 18–36 months. PMID:22795222

  13. Thrombelastographic changes and early rebleeding in cirrhotic patients with variceal bleeding

    PubMed Central

    Chau, T; Chan, Y; Patch, D; Tokunaga, S; Greenslade, L; Burroughs, A

    1998-01-01

    Background—Routine coagulation tests do not necessarily reflect haemostasis in vivo in cirrhotic patients, particularly those who have bleeding varices. Thrombelastography (TEG) can provide a global assessment of haemostatic function from initial clot formation to clot dissolution. 
Aim—To evaluate TEG changes in cirrhotic patients with variceal bleeding and their association with early rebleeding. 
Patients/Methods—Twenty cirrhotic patients with active variceal bleeding had serial TEG and routine coagulation tests daily for seven days. The TEG variables before the day of rebleeding (n = 6) were compared with those of patients without rebleeding (n =14). 
Results—Baseline characteristics of the rebleeding and non-rebleeding groups were comparable apart from a higher incidence of uncontrolled infection on the day of rebleeding in the rebleeding group (p = 0.007). The patients in the rebleeding group were more hypocoagulable before the day of rebleeding as shown by longer r (42 v 24 mm, p<0.001) and k (48 v 13 mm, p<0.001) and smaller a (12 v 38°, p<0.001) compared with the mean of daily results of the non-rebleeding group. Routine coagulation tests, however, showed no significant differences between the two groups. 
Conclusion—The results of serial TEG measurements suggest that hypocoagulability may be associated with early rebleeding in cirrhotic patients. 

 Keywords: thrombelastography; variceal bleeding; early rebleeding; cirrhosis PMID:10189856

  14. Management of non variceal upper gastrointestinal bleeding: position statement of the Catalan Society of Gastroenterology.

    PubMed

    García-Iglesias, Pilar; Botargues, Josep-Maria; Feu Caballé, Faust; Villanueva Sánchez, Càndid; Calvet Calvo, Xavier; Brullet Benedi, Enric; Cánovas Moreno, Gabriel; Fort Martorell, Esther; Gallach Montero, Marta; Gené Tous, Emili; Hidalgo Rosas, José-Manuel; Lago Macía, Amelia; Nieto Rodríguez, Ana; Papo Berger, Michel; Planella de Rubinat, Montserrat; Saló Rich, Joan; Campo Fernández de Los Ríos, Rafel

    2017-01-18

    In recent years there have been advances in the management of non-variceal upper gastrointestinal bleeding that have helped reduce rebleeding and mortality. This document positioning of the Catalan Society of Digestologia is an update of evidence-based recommendations on management of gastrointestinal bleeding peptic ulcer.

  15. Severe bleeding from esophageal varices resistant to endoscopic treatment in a non cirrhotic patient with portal hypertension

    PubMed Central

    Caronna, Roberto; Bezzi, Mario; Schiratti, Monica; Cardi, Maurizio; Prezioso, Giampaolo; Benedetti, Michele; Papini, Federica; Mangioni, Simona; Martino, Gabriele; Chirletti, Piero

    2008-01-01

    A non cirrhotic patient with esophageal varices and portal vein thrombosis had recurrent variceal bleeding unsuccessfully controlled by endoscopy and esophageal transection. Emergency transhepatic portography confirmed the thrombosed right branch of the portal vein, while the left branch appeared angulated, shifted and stenotic. A stent was successfully implanted into the left branch and the collateral vessels along the epatoduodenal ligament disappeared. In patients with esophageal variceal hemorrhage and portal thrombosis if endoscopy fails, emergency esophageal transection or nonselective portocaval shunting are indicated. The rare patients with only partial portal thrombosis can be treated directly with stenting through an angioradiologic approach. PMID:18644135

  16. A Rare Case of Gastric Variceal Hemorrhage Secondary to Infiltrative B-Cell Lymphoma

    PubMed Central

    Lenhart, Adrienne; Fernandez-Castillo, Juan; Mullins, Keith; Salgia, Reena

    2016-01-01

    Portal hypertension commonly arises in the setting of advanced liver cirrhosis and is the consequence of increased resistance within the portal vasculature. Less commonly, left-sided noncirrhotic portal hypertension can develop in a patient secondary to isolated obstruction of the splenic vein. We present a rare case of left-sided portal hypertension and isolated gastric varices in a patient with large B-cell lymphoma, who was treated with splenic artery embolization. The patient is a 73-year-old male with no previous history of liver disease, who presented with coffee ground emesis and melena. On admission to hospital, he was found to have a hemoglobin level of 3.4 g/l. Emergent esophagogastroduodenoscopy showed isolated bleeding gastric varices (IGV1 by Sarin classification) in the fundus and cardia with subsequent argon plasma coagulation injection. He was transferred to our tertiary center where work-up revealed normal liver function tests, and abdominal ultrasound showed patent hepatic/portal vasculature without cirrhosis. MRI demonstrated a large heterogeneously enhancing mass in the pancreatic tail, with invasion into the spleen and associated splenic vein thrombosis. Surgery consultation was obtained, but urgent splenectomy was not recommended. The patient instead underwent splenic artery embolization to prevent future bleeding from his known gastric varices. Pathology from a CT-guided biopsy was consistent with diffuse large B-cell lymphoma. PET imaging showed uptake in the splenic hilum/pancreatic tail region with no additional metastatic involvement. He was evaluated by the Hematology Department to initiate R-CHOP chemotherapy. During his outpatient follow-up, he reported no further episodes of melena or hematemesis. To the best of our knowledge, there have only been two published case reports of large B-cell lymphoma causing upper gastrointestinal bleeding from isolated gastric varices. These cases were treated with splenectomy or chemotherapy alone

  17. Usefulness of Transjugular Intrahepatic Portosystemic Shunt in the Management of Bleeding Ectopic Varices in Cirrhotic Patients

    SciTech Connect

    Vidal, V.; Joly, L.; Perreault, P.; Bouchard, L.; Lafortune, M.; Pomier-Layrargues, G.

    2006-04-15

    Purpose. To evaluate the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) in the control of bleeding from ectopic varices. Methods. From 1995 to 2004, 24 cirrhotic patients, bleeding from ectopic varices, mean age 54.5 years (range 15-76 years), were treated by TIPS. The etiology of cirrhosis was alcoholic in 13 patients and nonalcoholic in 11 patients. The location of the varices was duodenal (n = 5), stomal (n = 8), ileocolic (n = 6), anorectal (n = 3), umbilical (n = 1), and peritoneal (n 1). Results. TIPS controlled the bleeding in all patients and induced a decrease in the portacaval gradient from 19.7 {+-} 5.4 to 6.4 {+-} 3.1 mmHg. Postoperative complications included self-limited intra-abdominal bleeding (n = 2), self-limited hemobilia (n = 1), acute thrombosis of the shunt (n = 1), and bile leak treated by a covered stent (n = 1). Median follow-up was 592 days (range 28-2482 days). Rebleeding occurred in 6 patients. In 2 cases rebleeding was observed despite a post-TIPS portacaval gradient lower than 12 mmHg and was controlled by variceal embolization; 1 patient underwent surgical portacaval shunt and never rebled; in 3 patients rebleeding was related to TIPS stenosis and treated with shunt dilatation with addition of a new stent. The cumulative rate of rebleeding was 23% and 31% at 1 and 2 years, respectively. One- and 2-year survival rates were 80% and 76%, respectively. Conclusion. The present series demonstrates that bleeding from ectopic varices, a challenging clinical problem, can be managed safely by TIPS placement with low rebleeding and good survival rates.

  18. Can proton pump inhibitors reduce rebleeding following Histoacryl sclerotherapy for gastric variceal hemorrhage?

    PubMed Central

    Kim, Ka Rham; Jun, Chung Hwan; Cho, Kyu Man; Wi, Jin Woo; Park, Seon Young; Cho, Sung Bum; Lee, Wan Sik; Park, Chang Hwan; Joo, Young Eun; Kim, Hyun Soo; Choi, Sung Kyu; Rew, Jong Sun

    2015-01-01

    Background/Aims: To evaluate the efficacy of proton pump inhibitors (PPIs) in reducing rebleeding and bleeding-related death rates after endoscopic gastric variceal obliteration (GVO) using N-butyl-2-cyanoacrylate (NBC). Methods: This study enrolled 341 patients who were consecutively diagnosed with and treated for bleeding gastric varices. The patients were divided into PPI and non-PPI groups, and their endoscopic findings, initial hemostasis outcomes, rebleeding and bleeding-related death rates, and treatment-related complications were analyzed. Results: The rate of initial hemostasis was 97.1%. rebleeding occurred in 2.2% of patients within 2 weeks, 3.9% of patients within 4 weeks, 18.9% of patients within 6 months, and 27.6% of patients within 12 months of the GVO procedure. A previous history of variceal bleeding (relative risk [RR], 1.955; 95% confidence interval [CI], 1.263 to 3.028; p = 0.003) and use of PPIs (RR, 0.554; 95% CI, 0.352 to 0.873; p = 0.011) were associated with rebleeding. Child-Pugh class C (RR, 10.914; 95% CI, 4.032 to 29.541; p < 0.001), failure of initial hemostasis (RR, 13.329; 95% CI, 2.795 to 63.556; p = 0.001), and the presence of red-colored concomitant esophageal varices (RR, 4.096; 95% CI, 1.320 to 12.713; p = 0.015) were associated with bleeding-related death. Conclusions: The prophylactic use of PPIs reduces rebleeding after GVO using NBC in patients with gastric variceal hemorrhage. However, prophylactic use of PPIs does not reduce bleeding-related death. PMID:26354053

  19. Hemorrhagic ascites from spontaneous ectopic mesenteric varices rupture in NASH induced cirrhosis and successful outcome: a case report.

    PubMed

    Edula, Raja G R; Qureshi, Kamran; Khallafi, Hicham

    2014-07-07

    Bleeding from gastro-esophageal varices can often present as the first decompensating event in patients with cirrhosis. This can be a potentially life threatening event associated with a 15%-20% early mortality. We present a rare case of new onset ascites due to intra-abdominal hemorrhage from ruptured mesenteric varices; in a 37 years old male with newly diagnosed nonalcoholic steatohepatitis induced cirrhosis as the first decompensating event. The patient was successfully resuscitated with emergent evacuation of ascites for diagnosis, identification and control of bleeding mesenteric varices and eventually orthotopic liver transplantation with successful outcome. Various clinical presentations, available treatment options and outcomes of ectopic variceal bleeding are discussed in this report.

  20. Life-Threatening Bleeding from Peristomal Varices after Cystoprostatectomy: Multimodal Approach in a Cirrhotic, Encephalopathic Patient with Severe Portal Hypertension

    PubMed Central

    Staubli, Sergej E. L.; Gramann, Tobias; Schwab, Christoph; Semela, David; Hechelhammer, Lukas; Engeler, Daniel S.; Abt, Dominik; Mordasini, Livio

    2015-01-01

    The bleeding of peristomal varices due to a portosystemic shunt is rare but potentially life-threatening in cirrhotic patients with portal hypertension. The scarce case reports in the literature recommend transjugular intrahepatic portosystemic shunt (TIPS) to prevent further bleeding. We report on a 72-year-old man who was referred to our hospital because of life-threatening bleeding from peristomal varices, three years after radical cystoprostatectomy for invasive bladder cancer. CT imaging showed liver cirrhosis with a prominent portosystemic shunt leading to massively enlarged peristomal varices. TIPS was taken into consideration, but not possible due to hepatic encephalopathy (HE). Medical therapy with lactulose and the nonselective beta-blocker carvedilol was initiated to treat HE and portal hypertension. In a second step, the portosystemic shunt was percutaneously embolized. Here, we present a multimodal approach to treat intractable bleeding from peristomal varices in a patient with ileal conduit urinary diversion, not suitable for TIPS. PMID:25709851

  1. Assessment of variceal pressure by continuous non-invasive endoscopic registration: a placebo controlled evaluation of the effect of terlipressin and octreotide.

    PubMed Central

    Nevens, F; Van Steenbergen, W; Yap, S H; Fevery, J

    1996-01-01

    Octreotide has been proposed for the treatment of variceal bleeding. The effects on portal pressure, however, have been variable in published studies. As bleeding is more directly related to pressure in the varices, this study investigated the effect on variceal pressure of octreotide and terlipressin, a vasoactive drug with a well established effect. Variceal pressure was measured during four to eight minutes by a continuous non-invasive endoscopic registration method. Thirty patients in whom a stable variceal pressure recording had been obtained during at least one minute, were randomised to receive either 2 mg terlipressin, 50 micrograms octreotide or an identical volume of saline, as a single intravenous injection given over 60 seconds. For the final analysis three patients had to be excluded because of lack of a satisfactory recording. There were no significant clinical differences between the three groups of patients. Placebo administration did not induce significant changes, but a mean decrease in variceal pressure of -27% was noted with terlipressin, starting from two minutes onwards. Variceal pressure changes after injection of octreotide were variable and the mean change in pressure did not reach statistical significance. Seven of 10 patients showed a temporary increase in variceal pressure. In conclusion, terlipressin induces a significant and progressive decrease in variceal pressure but inconsistent variations of variceal pressure changes were seen after octreotide administration. This is probably related to its effect on central venous pressure. This study also shows that continuous variceal pressure recording with the non-invasive endoscopic registration technique detects in an accurate way the effect of vasoactive drugs on variceal pressure, because placebo injection did not produce significant changes. PMID:8566840

  2. Enzyme-mediated ligation technologies for peptides and proteins.

    PubMed

    Schmidt, Marcel; Toplak, Ana; Quaedflieg, Peter Jlm; Nuijens, Timo

    2017-02-18

    With the steadily increasing complexity and quantity requirements for peptides in industry and academia, the efficient and site-selective ligation of peptides and proteins represents a highly desirable goal. Within this context, enzyme-mediated ligation technologies for peptides and proteins have attracted great interest in recent years as they represent an extremely powerful extension to the scope of chemical methodologies (e.g. native chemical ligation) in basic and applied research. Compared to chemical ligation methods, enzymatic strategies using ligases such as sortase, butelase, peptiligase or omniligase generally feature excellent chemoselectivity, therefore making them valuable tools for protein and peptide chemists.

  3. Streamlined expressed protein ligation using split inteins.

    PubMed

    Vila-Perelló, Miquel; Liu, Zhihua; Shah, Neel H; Willis, John A; Idoyaga, Juliana; Muir, Tom W

    2013-01-09

    Chemically modified proteins are invaluable tools for studying the molecular details of biological processes, and they also hold great potential as new therapeutic agents. Several methods have been developed for the site-specific modification of proteins, one of the most widely used being expressed protein ligation (EPL) in which a recombinant α-thioester is ligated to an N-terminal Cys-containing peptide. Despite the widespread use of EPL, the generation and isolation of the required recombinant protein α-thioesters remain challenging. We describe here a new method for the preparation and purification of recombinant protein α-thioesters using engineered versions of naturally split DnaE inteins. This family of autoprocessing enzymes is closely related to the inteins currently used for protein α-thioester generation, but they feature faster kinetics and are split into two inactive polypeptides that need to associate to become active. Taking advantage of the strong affinity between the two split intein fragments, we devised a streamlined procedure for the purification and generation of protein α-thioesters from cell lysates and applied this strategy for the semisynthesis of a variety of proteins including an acetylated histone and a site-specifically modified monoclonal antibody.

  4. Upper non-variceal gastrointestinal bleeding - review the effectiveness of endoscopic hemostasis methods

    PubMed Central

    Szura, Mirosław; Pasternak, Artur

    2015-01-01

    Upper non-variceal gastrointestinal bleeding is a condition that requires immediate medical intervention and has a high associated mortality rate (exceeding 10%). The vast majority of upper gastrointestinal bleeding cases are due to peptic ulcers. Helicobacter pylori infection, non-steroidal anti-inflammatory drugs and aspirin are the main risk factors for peptic ulcer disease. Endoscopic therapy has generally been recommended as the first-line treatment for upper gastrointestinal bleeding as it has been shown to reduce recurrent bleeding, the need for surgery and mortality. Early endoscopy (within 24 h of hospital admission) has a greater impact than delayed endoscopy on the length of hospital stay and requirement for blood transfusion. This paper aims to review and compare the efficacy of the types of endoscopic hemostasis most commonly used to control non-variceal gastrointestinal bleeding by pooling data from the literature. PMID:26421105

  5. As fast and selective as enzymatic ligations: unpaired nucleobases increase the selectivity of DNA-controlled native chemical PNA ligation.

    PubMed

    Ficht, Simon; Dose, Christian; Seitz, Oliver

    2005-11-01

    DNA-controlled reactions offer interesting opportunities in biological, chemical, and nanosciences. In practical applications, such as in DNA sequence analysis, the sequence fidelity of the chemical-ligation reaction is of central importance. We present a ligation reaction that is as fast as and much more selective than enzymatic T4 ligase-mediated oligonucleotide ligations. The selectivity was higher than 3000-fold in discriminating matched from singly mismatched DNA templates. It is demonstrated that this enormous selectivity is the hallmark of the particular ligation architecture, which is distinct from previous ligation architectures designed as "nick ligations". Interestingly, the fidelity of the native chemical ligation of peptide nucleic acids was increased by more than one order of magnitude when performing the ligation in such a way that an abasic-site mimic was formed opposite an unpaired template base. It is shown that the high sequence fidelity of the abasic ligation could facilitate the MALDI-TOF mass-spectrometric analysis of early cancer onset by allowing the detection of as little as 0.2 % of single-base mutant DNA in the presence of 99.8 % wild-type DNA.

  6. Selective shunt in the management of variceal bleeding in the era of liver transplantation.

    PubMed Central

    Henderson, J M; Gilmore, G T; Hooks, M A; Galloway, J R; Dodson, T F; Hood, M M; Kutner, M H; Boyer, T D

    1992-01-01

    This study reports the Emory experience with 147 distal splenorenal shunts (DSRS) and 110 orthotopic liver transplants (OLT) between January 1987 and December 1991. The purpose was to clarify which patients with variceal bleeding should be treated by DSRS versus OLT. Distal splenorenal shunts were selected for patients with adequate or good liver function. Orthotopic liver transplant was offered to patients with end-stage liver disease who fulfilled other selection criteria. The DSRS group comprised 71 Child's A, 70 Child's B, and 6 Child's C patients. The mean galactose elimination capacity for all DSRS patients was 330 +/- 98 mg/minute, which was significantly (p less than 0.01) above the galactose elimination capacity of 237 +/- 82 mg/minute in the OLT group. Survival analysis for the DSRS group showed 91% 1-year and 77% 3-year survival, which was better than the 74% 1-year and 60% 3-year survivals in the OLT group. Variceal bleeding as a major component of end-stage disease leading to OLT had significantly (p less than 0.05) poorer survival (50%) at 1 year compared with patients without variceal bleeding (80%). Hepatic function was maintained after DSRS, as measured by serum albumin and prothrombin time, but galactose elimination capacity decreased significantly (p less than 0.05) to 298 +/- 97 mg/minute. Quality of life, measured by a self-assessment questionnaire, was not significantly different in the DSRS and OLT groups. Hospital charges were significantly higher for OLT (median, $113,733) compared with DSRS ($32,674). These data support a role for selective shunt in the management of patients with variceal bleeding who require surgery and have good hepatic function. Transplantation should be reserved for patients with end-stage liver disease. A thorough evaluation, including tests of liver function, help in selection of the most appropriate therapeutic approach. PMID:1417174

  7. Abdominal varices mimicking an acute gastrointestinal hemorrhage during technetium-99m red blood cell scintigraphy

    SciTech Connect

    Moreno, A.J.; Byrd, B.F.; Berger, D.E.; Turnbull, G.L.

    1985-04-01

    Abdominal varices consisting of a caput medusae and dilated mesenteric veins resulted in pooling of Tc-99m tagged red blood cells (RBC) within these dilated vessels in a 57-year-old man with severe Laennec's cirrhosis. The atypical radiotracer localization within the abdomen mimicked an acute gastrointestinal hemorrhage. Clinical suspicion and careful evaluation of scintigraphic gastrointestinal bleeding studies will avoid false-positive interpretations.

  8. High-resolution Manometry Findings in Patients After Sclerotherapy for Esophageal Varices

    PubMed Central

    Herbella, Fernando A M; Colleoni, Ramiro; Bot, Luiz; Vicentine, Fernando P P; Patti, Marco G

    2016-01-01

    Background/Aims Endoscopic therapy for esophageal varices may lead to esophageal dysmotility. High-resolution manometry is probably the more adequate tool to measure esophageal motility in these patients. This study aimed to evaluate esophageal motility using high resolution manometry following eradication of esophageal varices by endoscopic sclerotherapy. Methods We studied 21 patients (11 women, age 52 [45–59] years). All patients underwent eradication of esophageal varices with endoscopic sclerotherapy and subsequent high resolution manometry. Results A significant percentage of defective lower esophageal sphincter (basal pressure 14.3 [8.0–20.0] mmHg; 43% hypertonic) and hypocontractility (distal esophageal amplitude 50 [31–64] mmHg; proximal esophageal amplitude 40 [31–61] mmHg; distal contractile integral 617 [403–920] mmHg · sec · cm; 48% ineffective) was noticed. Lower sphincter basal pressure and esophageal amplitude correlated inversely with the number of sessions (P < 0.001). No manometric parameter correlated with symptoms or interval between last endoscopy and manometry. Conclusions Esophageal motility after endoscopic sclerotherapy is characterized by: (1) defective lower sphincter and (2) defective and hypotensive peristalsis. Esophageal dysmotility is associated to an increased number of endoscopic sessions, but manometric parameters do not predict symptoms. PMID:26554823

  9. Evaluation of embolization for periuterine varices involving chronic pelvic pain secondary to pelvic congestion syndrome

    PubMed Central

    Siqueira, Flavio Meirelles; Monsignore, Lucas Moretti; Rosa-e-Silva, Julio Cesar; Poli-Neto, Omero Benedicto; de Castro-Afonso, Luis Henrique; Nakiri, Guilherme Seizem; Muglia, Valdair Francisco; Abud, Daniel Giansante

    2016-01-01

    OBJECTIVES: To evaluate the clinical response and success rate after periuterine varices embolization in patients with chronic pelvic pain secondary to pelvic congestion syndrome and to report the safety of endovascular treatment and its rate of complications. METHODS: Retrospective cohort of patients undergoing endovascular treatment of pelvic congestion syndrome in our department from January 2012 to November 2015. Data were analyzed based on patient background, imaging findings, embolized veins, rate of complications, and clinical response as indicated by the visual analog pain scale. RESULTS: We performed periuterine varices embolization in 22 patients during the study, four of which required a second embolization. Seventeen patients reported a reduction in pelvic pain after the first embolization and three patients reported a reduction in pelvic pain after the second embolization. Minor complications were observed in our patients, such as postural hypotension, postoperative pain, and venous perforation during the procedure, without clinical repercussion. CONCLUSION: Periuterine varices embolization in patients with chronic pelvic pain secondary to pelvic congestion syndrome appears to be an effective and safe technique. PMID:28076514

  10. Somatostatin v placebo in bleeding oesophageal varices: randomised trial and meta-analysis.

    PubMed Central

    Gøtzsche, P. C.; Gjørup, I.; Bonnén, H.; Brahe, N. E.; Becker, U.; Burcharth, F.

    1995-01-01

    OBJECTIVE--To study whether somatostatin or its derivative octreotide is more effective than placebo for treating bleeding oesophageal varices. METHODS--Randomised, double blind trial and meta-analysis with blinded analysis of data and writing of manuscripts. SETTING--Departments of medical and surgical gastroenterology in Copenhagen. SUBJECTS--Patients suspected of bleeding from oesophageal varices and of having cirrhosis of the liver. MAIN OUTCOME MEASURES--Survival, number of blood transfusions, and use of Sengstaken-Blakemore tube. RESULTS--86 patients were randomised; in each group 16 died within six weeks (95% confidence interval for difference in mortality--19% to 22%). There were no differences between those treated with somatostatin or placebo in median number of blood transfusions (8 v 5, P = 0.07, 0 to 4 transfusions) or in numbers of patients who needed balloon tamponade (16 v 13, P = 0.54, -11% to 28%). In a meta-analysis of three trials involving 290 patients somatostatin had no effect on survival compared with placebo (P = 0.59, odds ratio 1.16; 0.67 to 2.01). For blood transfusions and use of balloon tamponade there was heterogeneity between the trials with no convincing evidence in favour of somatostatin. No placebo controlled trials have been performed with octreotide. CONCLUSION--Within the limited power of this study and meta-analysis we were unable to show a clinical benefit of somatostatin in the emergency treatment of bleeding oesophageal varices. PMID:7787594

  11. Prediction of oesophageal varices in patients with primary biliary cirrhosis by non-invasive markers

    PubMed Central

    Gao, Lili; Li, Hanwei; Han, Jun; Zhang, Weihui

    2017-01-01

    Introduction Preliminary data suggested that non-invasive methods could be useful to assess presence of oesophageal varices (OV) in liver cirrhosis. The primary objectives were to investigate non-invasive markers for diagnosing and grading OV in patients with primary biliary cirrhosis. Material and methods This study included a total of 106 consecutive treatment-naive patients with primary biliary cirrhosis (PBC). Results of physical examination, blood tests, and abdominal ultrasound scan (USS) were measured. Performance of non-invasive markers for OV was expressed as sensitivity, specificity, positive, and negative predictive values (PPV, NPV), accuracy, and area under the curve (AUC). Results Oesophageal varices were found in 54 (50.9%) and large OV in 28 of the 106 patients. Variables found to differ significantly between patients with any grade or large and without OV included increased spleen length, increased portal vein diameter, low platelet count, and low levels of albumin or low γ-glutamyltranspeptidase (γ-GTP) values. Area under the receiver operating characteristic curve showed that spleen length (cutoff = 156.0) had AUC 0.753 (95% CI: 0.657–0.849), and high NPV (82.1%) to exclude any grade OV. Large OV could be excluded with NPV 70.6% by spleen length. Conclusions Predictive risk factors that use readily available laboratory results and ultrasound scan results may reliably identify esophageal varices in patients with PBC. PMID:28261290

  12. (Bio)molecular surface patterning by phototriggered oxime ligation.

    PubMed

    Pauloehrl, Thomas; Delaittre, Guillaume; Bruns, Michael; Meißler, Maria; Börner, Hans G; Bastmeyer, Martin; Barner-Kowollik, Christopher

    2012-09-03

    Making light work of ligation: A novel method utilizes light for oxime ligation chemistry. A quantitative, low-energy photodeprotection generates aldehyde, which subsequently reacts with aminooxy moieties. The spatial control allows patterning on surfaces with a fluoro marker and GRGSGR peptide, and can be imaged by time-of-flight secondary-ion mass spectrometry.

  13. The inferior mesenteric vein to the left gonadal vein shunt for gastroesophageal varices and extrahepatic portal vein thrombosis after living donor liver transplantation: a case report.

    PubMed

    Kobayashi, T; Sato, Y; Yamamoto, S; Oya, H; Kokai, H; Hatakeyama, K

    2012-03-01

    This 59-year-old woman underwent living donor liver transplantation using a left lobe graft as an aid for autoimmune hepatitis in 2003. Splenectomy was also performed because of blood type incompatibility. Follow-up endoscopic and computed tomography examinations showed gastroesophageal varices with extra hepatic portal vein thrombosis in 2007 that increased (esophageal varices [EV]: locus superior [Ls], moderately enlarged, beady varices [F2], Blue varices [Cb], presence of small in number and localized red color sign [RC1] and telangiectasia [TE+], gastric varices [GV]: extension from the cardiac orifice to the fornix [Lg-cf], moderately enlarged, beady varices [F2], white varices [Cw], absence of red color sign [RC-]). Portal venous flow to the gastroesophageal varices was also confirmed from a large right gastric vein. The splenic vein was thrombosed. Blood flow to the liver graft was totally supplied from the hepatic artery. The graft was functioning well. Because these gastroesophageal varices had a high risk of variceal bleeding, we decided to proceed with a portal reconstruction of a surgical portosystemic shunt in 2008. Severe adhesions were observed around the portal vein. It was impossible to perform portal reconstruction. There were relatively fewes adhesious in the left lower side of the abdominal cavity. We decided to create an inferior mesenteric vein to left gonadal vein shunt. The portal vein pressure decreased from 31.0 to 21.5 cm H2O thereafter. The postoperative course was smooth without any complication. This patient was discharged on the postoperative day 15. Follow-up endoscopic study showed the improvement in the gastroesophageal varices (EV: Ls, F2, Cb, RC(-), GV: Lg-c, F2, Cw, RC-) at 3 months after the operation. We also comfirmed the patency of the shunt by serial computed tomography examinations.

  14. A new 10-min ligation method using a modified buffer system with a very low amount of T4 DNA ligase: the "Coffee Break Ligation" technique.

    PubMed

    Yoshino, Yuki; Ishida, Masaharu; Horii, Akira

    2007-10-01

    The ligation reaction is widely used in molecular biology. There are several kits available that complete the ligation reaction very rapidly but they are rather expensive. In this study, we successfully modified the ligation buffer with much lower cost than existing kits. The ligation reaction can be completed in 10 min using very low activities such as 0.01 U T4 DNA ligase, and costs only $1 for 100 reactions of 20 microl scale. We name this ligation system the "Coffee Break Ligation" system; one can complete ligation reaction while drinking a cup of coffee, and perform 100 reactions by spending money equivalent to a cup of coffee.

  15. Irreversible sortase A-mediated ligation driven by diketopiperazine formation.

    PubMed

    Liu, Fa; Luo, Ethan Y; Flora, David B; Mezo, Adam R

    2014-01-17

    Sortase A (SrtA)-mediated ligation has emerged as an attractive tool in bioorganic chemistry attributing to the remarkable specificity of the ligation reaction and the physiological reaction conditions. However, the reversible nature of this reaction limits the efficiency of the ligation reaction and has become a significant constraint to its more widespread use. We report herein a novel set of SrtA substrates (LPETGG-isoacyl-Ser and LPETGG-isoacyl-Hse) that can be irreversibly ligated to N-terminal Gly-containing moieties via the deactivation of the SrtA-excised peptide fragment through diketopiperazine (DKP) formation. The convenience of the synthetic procedure and the stability of the substrates in the ligation buffer suggest that both LPETGG-isoacyl-Ser and LPETGG-isoacyl-Hse are valuable alternatives to existing irreversible SrtA substrate sequences.

  16. A simple microfluidic assay for the detection of ligation product.

    PubMed

    Zhang, Lei; Wang, Jingjing; Roebelen, Johann; Tripathi, Anubhav

    2015-02-01

    We present a novel microfluidic-based approach to detect ligation products. The conformal specificity of ligases is used in various molecular assays to detect point mutations. Traditional methods of detecting ligation products include denaturing gel electrophoresis, sequence amplification, and melting curve analysis. Gel electrophoresis is a labor- and time-intensive process, while sequence amplification and melting curve analysis require instruments capable of accurate thermal ramping and sensitive optical detection. Microfluidics has been widely applied in genomics, proteomics, and cell cytometry to enable rapid and automated assays. We designed an assay that fluorogenically detects ligation products following a simple magnetic separation through a microfluidic channel. 100 nM of synthetic HIV-1 K103N minority mutant templates were successfully detected in 30 min. This simple and rapid method can be coupled with any ligation assay for the detection of ligation products.

  17. Template-directed oligonucleotide ligation on hydroxylapatite

    NASA Technical Reports Server (NTRS)

    Acevedo, O. L.; Orgel, L. E.

    1986-01-01

    It has been suggested that the prebiotic synthesis of the precursors of biopolymers could have occurred on a solid surface such as that provided by clay or some other mineral. One such scheme envisages that growing polymers were localized by adsorption to a mineral surface where an activating agent or activated monomers were supplied continuously or cyclically. Here, it is reported that a sequence of reactions in which initially formed oligo(G)s are reactivated by conversion to phosphorimidazolides in the presence of poly(C) and then allowed to ligate is ideal, in that repeated cycles can be carried out on the surface of hydroxylapatite, whereas in the liquid phase the cycle could be achieved only with considerable difficulty.

  18. Cost-effectiveness analysis of beta-blockers vs endoscopic surveillance in patients with cirrhosis and small varices

    PubMed Central

    Di Pascoli, Lorenza; Buja, Alessandra; Bolognesi, Massimo; Montagnese, Sara; Gatta, Angelo; Gregori, Dario; Merkel, Carlo

    2014-01-01

    AIM: To evaluate the most cost-effectiveness strategy for preventing variceal growth and bleeding in patients with cirrhosis and small esophageal varices. METHODS: A stochastic analysis based on decision trees was performed to compare the cost-effectiveness of beta-blockers therapy starting from a diagnosis of small varices (Strategy 1) with that of endoscopic surveillance followed by beta-blockers treatment when large varices are demonstrated (Strategy 2), for preventing variceal growth, bleeding and death in patients with cirrhosis and small esophageal varices. The basic nodes of the tree were gastrointestinal endoscopy, inpatient admission and treatment for bleeding, as required. All estimates were performed using a Monte Carlo microsimulation technique, consisting in simulating observations from known probability distributions depicted in the model. Eight-hundred-thousand simulations were performed to obtain the final estimates. All estimates were then subjected to Monte Carlo Probabilistic sensitivity analysis, to assess the impact of the variability of such estimates on the outcome distributions. RESULTS: The event rate (considered as progression of varices or bleeding or death) in Strategy 1 [24.09% (95%CI: 14.89%-33.29%)] was significantly lower than in Strategy 2 [60.00% (95%CI: 48.91%-71.08%)]. The mean cost (up to the first event) associated with Strategy 1 [823 £ (95%CI: 106 £-2036 £)] was not significantly different from that of Strategy 2 [799 £ (95%CI: 0 £-3498 £)]. The cost-effectiveness ratio with respect to this endpoint was equal to 50.26 £ (95%CI: -504.37 £-604.89 £) per event avoided over the four-year follow-up. When bleeding episodes/deaths in subjects whose varices had grown were included, the mean cost associated with Strategy 1 was 1028 £ (95%CI: 122 £-2581 £), while 1699 £ (95%CI: 171 £-4674 £) in Strategy 2. CONCLUSION: Beta-blocker therapy turn out to be more effective and less expensive than endoscopic surveillance for

  19. A multicentre randomised trial comparing octreotide and injection sclerotherapy in the management and outcome of acute variceal haemorrhage

    PubMed Central

    Jenkins, S; Shields, R; Davies, M; Elias, E; Turnbull, A; Bassendine, M; James, O; Iredale, J; Vyas, S; Arthur, M; Kingsnorth, A; Sutton, R

    1997-01-01

    Background—Few studies have compared vasoactive drugs with endoscopic sclerotherapy in the control of acute variceal haemorrhage. Octreotide is widely used for this purpose, but its value remains undetermined. 
Aims—To compare octreotide with endoscopic sclerotherapy for acute variceal haemorrhage. 
Patients—Consecutive patients with acute variceal haemorrhage. 
Methods—Patients were randomised at endoscopy to receive either a 48 hour intravenous infusion of 50 µg/h octreotide (n=73), or emergency sclerotherapy (n=77). 
Results—Overall control of bleeding and mortality was not significantly different between octreotide (85%, 62 patients) and sclerotherapy (82%, 63 patients) over the 48 hour trial period (relative risk of rebleeding 0.83; 95% confidence interval (CI) 0.38 to 1.82), irrespective of Child's grading or active bleeding at endoscopy. One major complication was observed in the sclerotherapy group (aspiration) and two in the octreotide group (pulmonary oedema, severe paralytic ileus). During 60 days of follow up there was an overall trend towards an increased mortality in the octreotide group which was not statistically significant (relative risk of dying at 60 days 1.91, 95% CI 0.97 to 3.78, p=0.06). 
Conclusions—The results of this study indicate that intravenous octreotide is as effective as injection sclerotherapy in the control of acute variceal bleeding, but further controlled trials are necessary to evaluate the safety of this treatment. 

 Keywords: variceal haemorrhage; octreotide; injection sclerotherapy PMID:9391254

  20. Balloon-Occluded Antegrade Transvenous Sclerotherapy to Treat Rectal Varices: A Direct Puncture Approach to the Superior Rectal Vein Through the Greater Sciatic Foramen Under CT Fluoroscopy Guidance

    SciTech Connect

    Ono, Yasuyuki Kariya, Shuji Nakatani, Miyuki Yoshida, Rie Kono, Yumiko Kan, Naoki Ueno, Yutaka Komemushi, Atsushi Tanigawa, Noboru

    2015-10-15

    Rectal varices occur in 44.5 % of patients with ectopic varices caused by portal hypertension, and 48.6 % of these patients are untreated and followed by observation. However, bleeding occurs in 38 % and shock leading to death in 5 % of such patients. Two patients, an 80-year-old woman undergoing treatment for primary biliary cirrhosis (Child-Pugh class A) and a 63-year-old man with class C hepatic cirrhosis (Child-Pugh class A), in whom balloon-occluded antegrade transvenous sclerotherapy was performed to treat rectal varices are reported. A catheter was inserted by directly puncturing the rectal vein percutaneously through the greater sciatic foramen under computed tomographic fluoroscopy guidance. In both cases, the rectal varices were successfully treated without any significant complications, with no bleeding from rectal varices after embolization.

  1. Efficient Ligation of the Schistosoma Hammerhead Ribozyme †

    PubMed Central

    Canny, Marella D.; Jucker, Fiona M.; Pardi, Arthur

    2011-01-01

    The hammerhead ribozyme from Schistosoma mansoni is the best characterized of the natural hammerhead ribozymes. Biophysical, biochemical, and structural studies have shown that the formation of the loop-loop tertiary interaction between stems I and II alters the global folding, cleavage kinetics, and conformation of the catalytic core of this hammerhead, leading to a ribozyme that is readily cleaved under physiological conditions. This study investigates the ligation kinetics and the internal equilibrium between cleavage and ligation for the Schistosoma hammerhead. Single turnover kinetic studies on a construct where the ribozyme cleaves and ligates substrate(s) in trans showed up to 23% ligation when starting from fully cleaved products. This was achieved by a ~2,000-fold increase in the rate of ligation compared to a minimal hammerhead without the loop-loop tertiary interaction, yielding an internal equilibrium that ranges from 2–3 at physiological Mg2+ ion concentrations (0.1 –1 mM). Thus, the natural Schistosoma hammerhead ribozyme is almost as efficient at ligation as it is at cleavage. The results here are consistent with a model where formation of the loop-loop tertiary interaction leads to a higher population of catalytically active molecules, and where formation of this tertiary interaction has a much larger effect on the ligation than the cleavage activity of the Schistosoma hammerhead ribozyme. PMID:17319693

  2. Selective suppression of interleukin-12 induction after macrophage receptor ligation.

    PubMed

    Sutterwala, F S; Noel, G J; Clynes, R; Mosser, D M

    1997-06-02

    Interleukin (IL)-12 is a monocyte- and macrophage-derived cytokine that plays a crucial role in both the innate and the acquired immune response. In this study, we examined the effects that ligating specific macrophage receptors had on the induction of IL-12 by lipopolysaccharide (LPS). We report that ligation of the macrophage Fcgamma, complement, or scavenger receptors inhibited the induction of IL-12 by LPS. Both mRNA synthesis and protein secretion were diminished to near-undetectable levels following receptor ligation. Suppression was specific to IL-12 since IL-10 and tumor necrosis factor-alpha (TNF-alpha) production were not inhibited by ligating macrophage receptors. The results of several different experimental approaches suggest that IL-12 downregulation was due to extracellular calcium influxes that resulted from receptor ligation. First, preventing extracellular calcium influxes, by performing the assays in EGTA, abrogated FcgammaR-mediated IL-12(p40) mRNA suppression. Second, exposure of macrophages to the calcium ionophores, ionomycin or A23187, mimicked receptor ligation and inhibited IL-12(p40) mRNA induction by LPS. Finally, bone marrow-derived macrophages from FcR gamma chain-deficient mice, which fail to flux calcium after receptor ligation, failed to inhibit IL-12(p40) mRNA induction. These results indicate that the calcium influxes that occur as a result of receptor ligation are responsible for inhibiting the induction of IL-12 by LPS. Hence, the ligation of phagocytic receptors on macrophages can lead to a dramatic decrease in IL-12 induction. This downregulation may be a way of limiting proinflammatory responses of macrophages to extracellular pathogens, or suppressing the development of cell-mediated immunity to intracellular pathogens.

  3. Delayed onset pulmonary glue emboli in a ventilated patient: a rare complication following endoscopic cyanoacrylate injection for gastric variceal haemorrhage.

    PubMed

    Chew, Joyce Ruo Yi; Balan, Anu; Griffiths, William; Herre, Jurgen

    2014-10-15

    Cyanoacrylate injection is a recognised endoscopic treatment option for variceal haemorrhage. We describe a 34-year old man with hepatitis B cirrhosis who presented to the hospital with upper gastrointestinal haemorrhage from gastric and oesophageal varices. Haemostasis was achieved via cyanoacrylate injection sclerotherapy and banding. Ten days later, the patient developed acute hypoxia and fever. His chest radiograph showed wide-spread pulmonary shadowing. A non-contrast CT scan confirmed multiple emboli of injected glue material from the varix with parenchymal changes either suggesting acute lung injury or pulmonary oedema. He gradually recovered with supportive treatment and was discharged home. On follow-up, he remained asymptomatic from a chest perspective. This case report discusses the rare complication of pulmonary embolisation of cyanoacrylate glue from variceal injection sites and the diagnostic dilemmas involved. Emphasis is placed on the importance of maintaining high index of clinical suspicion when assessing patients with possible procedure related complications.

  4. Analysis of Genes, Transcripts, and Proteins via DNA Ligation

    NASA Astrophysics Data System (ADS)

    Conze, Tim; Shetye, Alysha; Tanaka, Yuki; Gu, Jijuan; Larsson, Chatarina; Göransson, Jenny; Tavoosidana, Gholamreza; Söderberg, Ola; Nilsson, Mats; Landegren, Ulf

    2009-07-01

    Analytical reactions in which short DNA strands are used in combination with DNA ligases have proven useful for measuring, decoding, and locating most classes of macromolecules. Given the need to accumulate large amounts of precise molecular information from biological systems in research and in diagnostics, ligation reactions will continue to offer valuable strategies for advanced analytical reactions. Here, we provide a basis for further development of methods by reviewing the history of analytical ligation reactions, discussing the properties of ligation reactions that render them suitable for engineering novel assays, describing a wide range of successful ligase-based assays, and briefly considering future directions.

  5. Convergent synthesis of proteins by kinetically controlled ligation

    DOEpatents

    Kent, Stephen; Pentelute, Brad; Bang, Duhee; Johnson, Erik; Durek, Thomas

    2010-03-09

    The present invention concerns methods and compositions for synthesizing a polypeptide using kinetically controlled reactions involving fragments of the polypeptide for a fully convergent process. In more specific embodiments, a ligation involves reacting a first peptide having a protected cysteyl group at its N-terminal and a phenylthioester at its C-terminal with a second peptide having a cysteine residue at its N-termini and a thioester at its C-termini to form a ligation product. Subsequent reactions may involve deprotecting the cysteyl group of the resulting ligation product and/or converting the thioester into a thiophenylester.

  6. Formatting and ligating biopolymers using adjustable nanoconfinement

    NASA Astrophysics Data System (ADS)

    Berard, Daniel J.; Shayegan, Marjan; Michaud, Francois; Henkin, Gil; Scott, Shane; Leslie, Sabrina

    2016-07-01

    Sensitive visualization and conformational control of long, delicate biopolymers present critical challenges to emerging biotechnologies and biophysical studies. Next-generation nanofluidic manipulation platforms strive to maintain the structural integrity of genomic DNA prior to analysis but can face challenges in device clogging, molecular breakage, and single-label detection. We address these challenges by integrating the Convex Lens-induced Confinement (CLiC) technique with a suite of nanotopographies embedded within thin-glass nanofluidic chambers. We gently load DNA polymers into open-face nanogrooves in linear, concentric circular, and ring array formats and perform imaging with single-fluorophore sensitivity. We use ring-shaped nanogrooves to access and visualize confinement-enhanced self-ligation of long DNA polymers. We use concentric circular nanogrooves to enable hour-long observations of polymers at constant confinement in a geometry which eliminates the confinement gradient which causes drift and can alter molecular conformations and interactions. Taken together, this work opens doors to myriad biophysical studies and biotechnologies which operate on the nanoscale.

  7. Covered TIPS for secondary prophylaxis of variceal bleeding in liver cirrhosis

    PubMed Central

    Qi, Xingshun; Tian, Yulong; Zhang, Wei; Zhao, Haitao; Han, Guohong; Guo, Xiaozhong

    2016-01-01

    Abstract Background: In the era of bare stents, transjugular intrahepatic portosystemic shunt (TIPS) is the second-line choice of therapy for the prevention of variceal rebleeding in liver cirrhosis. In the era of covered stents, the role of TIPS should be re-evaluated. Aim: The aim of the study was to compare the outcomes of covered TIPS versus the traditional first-line therapy (i.e, drug plus endoscopic therapy) for the prevention of variceal rebleeding in liver cirrhosis. Methods: All relevant randomized controlled trials were searched via the PubMed, EMBASE, and Cochrane Library databases. Hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) and P values were calculated for the cumulative risk and overall risk, respectively. Heterogeneity among studies was also calculated. Results: Three of 111 retrieved papers were eligible. Among them, the proportion of patients who were switched from drug plus endoscopic therapy to TIPS was 16% to 25%. The risk of bias was relatively low in all included randomized controlled trials. Meta-analyses demonstrated that the covered TIPS group had a similar overall survival (HR = 0.84, 95% CI = 0.55–1.28, P = 0.41; OR = 1.00, 95% CI = 0.59–1.69, P = 0.99), a significantly lower risk of variceal rebleeding (HR = 0.30, 95% CI = 0.18–0.48, P < 0.00001; OR = 0.24, 95% CI = 0.12–0.46, P < 0.0001), and a similar risk of hepatic encephalopathy (HR = 1.35, 95% CI = 0.72–2.53, P = 0.36; OR = 1.28, 95% CI = 0.54–3.04, P = 0.57). In most of meta-analyses, the heterogeneity among studies was not statistically significant. Conclusions: Compared with drug plus endoscopic therapy, covered TIPS had a significant benefit of preventing from variceal rebleeding, but did not increase the overall survival or risk of hepatic encephalopathy. PMID:27977618

  8. Adrenal pseudomasses due to varices: angiographic-CT-MRI-pathologic correlations

    SciTech Connect

    Brady, T.M.; Gross, B.H.; Glazer, G.M. Williams, D.M.

    1985-08-01

    Periadrenal and adrenal portosystemic collaterals are a recently reported cause of adrenal pseudotumor on computed tomography (CT). Nine patients with this left adrenal pseudotumor illustrate its typical position and appearance on CT, angiography, CT-angiography, and magnetic resonance imaging (MRI). The anatomic basis for variceal adrenal pseudotumors is the left inferior phrenic vein, which passes immediately anterior to the left adrenal gland and which serves as a collateral pathway from splenic to left renal vein in portal hypertension. Thus, unlike previously described adrenal pseudotumors, these venous collaterals are not anatomically distinguishable from the adrenal gland on CT. Bolus dynamic CT is usually diagnostic, but in equivocal cases, MRI may prove useful.

  9. Modelling Factors Causing Mortality in Oesophageal VaricesPatients in King Abdul Aziz University Hospital

    PubMed Central

    Bahlas, Sami

    2009-01-01

    Objectives The objective of this study is to reach a model defining factors precipitating short survival in patients with oesophageal varices and improving the understanding of such factors. Models would help to prioritize the clinical goals and intervention for saving the lives of patients. Methods Retrospective analysis of all patients admitted to King Abdul Aziz University Hospital who had been diagnosed with oesophageal varices. The patients’ demographics, disease history, physical examination, viral infections, parasitic infections, blood pictures, cancer biomarkers, liver enzymes and bleeding details were collected, tested for correlation with mortality to formulate a model. Results A total of 148 patients were included in this study. 37 clinical variables were studied only 15 factors were found to have a statistical significance. These factors were PT (RC=0.17338 P-value 0.00011), APTT (RC=0.07916, P-value 0.00002), haemoglobin level (RC=-0.44748, P-value <0.0001), WBC (RC = 0.22255, P-value 0.00001), serum albumin level (RC=-0.12953, P-value 0.00001), serum creatinine (RC=0.01483, P-value 0.00002), at least one incidence of encephalopathy (RC=1.80500, P-value 0.00014), total bilirubin (RC=0.01371, P-value 0.00016), direct bilirubin (RC=0.01298, P-value 0.00357, serum AST (RC=0.00914, P-value 0.00462), presence of at least bleeding event (RC=1.03373, P-value 0.00613), ascites grade I (RC=-1.57435, P-value 0.00967), SBP (RC=1.47216, P-value 0.01581), platelets count (RC=0.00398, P-value 0.03476) and oesophageal varices (RC = -1.42139, P-value 0.03673). Only 5 factors were likely to affect the mortality status. These factors were encephalopathy, spontaneous SBP, bleeding, ascites and grade of oesophageal varices. Six models were then formulated. Conclusion These models should be retested in larger study groups to test their reliability in order to use them as surrogate end point in future clinical studies. PMID:22224185

  10. Systemic Mastocytosis Complicated by Non-Cirrhotic Portal Hypertension and Variceal Bleeding

    PubMed Central

    McCarty, Thomas R.; Hung, Adelina; Mohanty, Arpan

    2017-01-01

    Systemic mastocytosis is a myeloproliferative disorder characterized by extracutaneous involvement of at least one organ. Although rare, infiltration of inflammatory mast cells within the portal vein may lead to obstruction of the sinusoids resulting in non-cirrhotic portal hypertension. We present a patient with known history of systemic mastocytosis with bone marrow involvement presenting with new-onset esophageal variceal bleeding. Although systemic mastocytosis is uncommon, the subsequent development of hepatic involvement and non-cirrhotic portal hypertension are discussed. Further highlighted is a lack of organization guidelines and the potential for gastrointestinal and hepatic screening of mastocytosis patients with known extracutaneous involvement. PMID:28286795

  11. A Photo-Triggered Traceless Staudinger-Bertozzi Ligation Reaction.

    PubMed

    Hu, Peng; Feng, Tianshi; Yeung, Chi-Chung; Koo, Chi-Kin; Lau, Kai-Chung; Lam, Michael H W

    2016-08-08

    The use of light to control the course of a chemical/biochemical reaction is an attractive idea because of its ease of administration with high precision and fine spatial resolution. Staudinger ligation is one of the commonly adopted conjugation processes that involve a spontaneous reaction between azides and arylphosphines to form iminophosphoranes, which further hydrolyze to give stable amides. We designed an anthracenylmethyl diphenylphosphinothioester (1) that showed promising Staudinger ligation reactivity upon photo-excitation. Broadband photolysis at 360-400 nm in aqueous organic solvents induced heterolytic cleavage of its anthracenylmethyl-phosphorus bond, releasing a diphenylphosphinothioester (2) as an efficient traceless Staudinger-Bertozzi ligation reagent. The quantum yield of such a photo-induced heterolytic bond-cleavage at the optimal wavelength of photolysis (376 nm) at room temperature is ≥0.07. This work demonstrated the feasibility of photocaging arylphosphines to realize the photo-triggering of the Staudinger ligation reaction.

  12. Cross-ligation and exchange reactions catalyzed by hairpin ribozymes.

    PubMed Central

    Komatsu, Y; Koizumi, M; Sekiguchi, A; Ohtsuka, E

    1993-01-01

    The negative strand of the satellite RNA of tobacco ringspot virus (sTobRV(-)) contains a hairpin catalytic domain that shows self-cleavage and self-ligation activities in the presence of magnesium ions. We describe here that the minimal catalytic domain can catalyze a cross-ligation reaction between two kinds of substrates in trans. The cross-ligated product increased when the reaction temperature was decreased during the reaction from 37 degrees C to 4 degrees C. A two-stranded hairpin ribozyme, divided into two fragments between G45 and U46 in a hairpin loop, showed higher ligation activity than the nondivided ribozyme. The two stranded ribozyme also catalyzed an exchange reaction of the 3'-portion of the cleavage site. Images PMID:8441626

  13. Hairpin ribozyme-catalyzed ligation in water-alcohol solutions.

    PubMed

    Vlassov, Alexander V; Johnston, Brian H; Kazakov, Sergei A

    2005-12-01

    The hairpin ribozyme (HPR) is a naturally existing RNA that catalyzes site-specific RNA cleavage and ligation. At 37 degrees C and in the presence of divalent metal ions (M(2+)), the HPR efficiently cleaves RNA substrates in trans. Here, we show that the HPR can catalyze efficient M(2+)-independent ligation in trans in aqueous solutions containing any of several alcohols, including methanol, ethanol, and isopropanol, and millimolar concentrations of monovalent cations. Ligation proceeds most efficiently in 60% isopropanol at 37 degrees C, whereas the reverse (cleavage) reaction is negligible under these conditions. We suggest that dehydration of the RNA is the key factor promoting HPR activity in water- alcohol solutions. Alcohol-induced ribozyme ligation may have practical applications.

  14. X-ray snapshots for metalloporphyrin axial ligation

    SciTech Connect

    Chen, L. X.; Zhang, X.; Wasinger, E. C.; Lockard, J. V.; Stickrath, A. B.; Mara, M. W.; Attenkofer, K.; Jennings, G.; Smolentsev, G.; Soldatov, A.

    2010-01-01

    Axial ligation mechanisms of a metalloporphyrin, nickel(II) tetramesitylporphyrin (NiTMP), were investigated by static and transient X-ray absorption spectroscopy at Ni K-edge (8.333 keV). A surprisingly broad (i.e. {approx}1.4 eV) linewidth for the 1s {yields} 3d{sub x2-y2} transition in the ground state was attributed to strong geometry dependent 3d molecular orbital (MO) energies due to coexisting conformers in solution. The broad distribution of 3d MO energy levels enables transient degeneracy of the 3d{sub z2} and 3d{sub x2-y2} MOs to produce a temporary vacancy in the 3d{sub z2} MO which favors axial ligation. Photoexcitation also induces the vacancy in the 3d{sub z2} MO, leading to a more than two-fold enhancement in the axial ligated species. Therefore, a unified axial ligation mechanism for both the ground and excited state is proposed based on the elucidation of the excited state structural dynamics, which will have a broad impact in understanding and controlling axial ligation in enzymatic reactions and molecular catalysis involving transient axial ligation.

  15. Rubber band ligation of hemorrhoids: A guide for complications

    PubMed Central

    Albuquerque, Andreia

    2016-01-01

    Rubber band ligation is one of the most important, cost-effective and commonly used treatments for internal hemorrhoids. Different technical approaches were developed mainly to improve efficacy and safety. The technique can be employed using an endoscope with forward-view or retroflexion or without an endoscope, using a suction elastic band ligator or a forceps ligator. Single or multiple ligations can be performed in a single session. Local anaesthetic after ligation can also be used to reduce the post-procedure pain. Mild bleeding, pain, vaso-vagal symptoms, slippage of bands, priapism, difficulty in urination, anal fissure, and chronic longitudinal ulcers are normally considered minor complications, more frequently encountered. Massive bleeding, thrombosed hemorrhoids, severe pain, urinary retention needing catheterization, pelvic sepsis and death are uncommon major complications. Mild pain after rubber band ligation is the most common complication with a high frequency in some studies. Secondary bleeding normally occurs 10 to 14 d after banding and patients taking anti-platelet and/or anti-coagulant medication have a higher risk, with some reports of massive life-threatening haemorrhage. Several infectious complications have also been reported including pelvic sepsis, Fournier’s gangrene, liver abscesses, tetanus and bacterial endocarditis. To date, seven deaths due to these infectious complications were described. Early recognition and immediate treatment of complications are fundamental for a favourable prognosis. PMID:27721924

  16. Ligation with nucleic acid sequence-based amplification.

    PubMed

    Ong, Carmichael; Tai, Warren; Sarma, Aartik; Opal, Steven M; Artenstein, Andrew W; Tripathi, Anubhav

    2012-01-01

    This work presents a novel method for detecting nucleic acid targets using a ligation step along with an isothermal, exponential amplification step. We use an engineered ssDNA with two variable regions on the ends, allowing us to design the probe for optimal reaction kinetics and primer binding. This two-part probe is ligated by T4 DNA Ligase only when both parts bind adjacently to the target. The assay demonstrates that the expected 72-nt RNA product appears only when the synthetic target, T4 ligase, and both probe fragments are present during the ligation step. An extraneous 38-nt RNA product also appears due to linear amplification of unligated probe (P3), but its presence does not cause a false-positive result. In addition, 40 mmol/L KCl in the final amplification mix was found to be optimal. It was also found that increasing P5 in excess of P3 helped with ligation and reduced the extraneous 38-nt RNA product. The assay was also tested with a single nucleotide polymorphism target, changing one base at the ligation site. The assay was able to yield a negative signal despite only a single-base change. Finally, using P3 and P5 with longer binding sites results in increased overall sensitivity of the reaction, showing that increasing ligation efficiency can improve the assay overall. We believe that this method can be used effectively for a number of diagnostic assays.

  17. Association of Oesophageal Varices and Splanchnic Vein Thromboses in Patients with JAK2-Positive Myeloproliferative Neoplasms: Presentation of Two Cases and Data from a Retrospective Analysis

    PubMed Central

    Link, Cornelia S.; Platzbecker, Uwe; Kroschinsky, Frank; Pannach, Sven; Thiede, Christian; Platzek, Ivan; Ehninger, Gerhard; Schuler, Markus K.

    2013-01-01

    Background Oesophageal varices and gastrointestinal bleeding are common complications of liver cirrhosis. More rarely, oesophageal varices occur in patients with non-cirrhotic portal hypertension that results from thromboses of portal or splanchnic veins. Case Report We describe 2 young men who initially presented with varices as a result of portal vein thromboses. In the clinical follow-up, both were tested positive for a JAK2 mutation and consequently diagnosed with myeloproliferative neoplasms (MPNs). In an attempt to characterise the frequency of gastrointestinal complications in patients with JAK2-positive MPNs, we retrospectively analysed all known affected patients from our clinic for the diagnosis of portal vein thromboses and oesophageal varices. Strikingly, 48% of those who had received an oesophagogastroduodenoscopy had detectable oesophageal or gastric varices, and 82% of those suffered from portal or splanchnic vein thromboses. Conclusion While the association between JAK2, myeloproliferative disease and thrombotic events is well established, patients with idiopathic oesophageal varices are not regularly tested for JAK2 mutations. However, the occurrence of oesophageal varices may be the first presenting symptom of a MPN with a JAK2 mutation, and affected patients may profit from a close haematological monitoring to assure the early detection of developing MPN. PMID:23898274

  18. A comparative study of Barron's rubber band ligation with Kshar Sutra ligation in hemorrhoids

    PubMed Central

    Singh, Rakhi; Arya, Ramesh C.; Minhas, Satinder S.; Dutt, Anil

    2010-01-01

    Despite a long medical history of identification and treatment, hemorrhoids still pose a challenge to the medical fraternity in terms of finding satisfactory cure of the disease. In this study, Kshar Sutra Ligation (KSL), a modality of treatment described in Ayurveda, was compared with Barron's Rubber Band Ligation (RBL) for grade II and grade III hemorrhoids. This study was conducted in 20 adult patients of either sex with grade II and grade III hemorrhoids at two different hospitals. Patients were randomly allotted to two groups of 10 patients each. Group I patients underwent RBL, whereas patients of group II underwent KSL. Guggul-based Apamarga Kshar Sutra was prepared according to the principles laid down in ancient Ayurvedic texts and methodology standardized by IIIM, Jammu and CDRI, Lucknow. Comparative assessment of RBL and KSL was done according to 16 criteria. Although the two procedures were compared on 15 criteria, treatment outcome of grade II and grade III hemorrhoids was decided chiefly on the basis of patient satisfaction index (subjective criterion) and ability of each procedure to deal with prolapse of internal hemorrhoidal masses (objective criterion): Findings in each case were recorded over a follow-up of four weeks (postoperative days 1, 3, 7, 15 and 30). Statistical analysis was done using Student's t test for parametric data and Chi square test & Mann-Whitney test for non-parametric data. P < 0.05 was considered significant. RBL had the advantages of being an OPD procedure requiring no anesthesia and was attended by significantly lesser postoperative recumbency (P < 0.001 ) and significantly lesser pain (P < 0.005 on day 1) as compared to KSL. However, Group II (KSL) scored better in terms of treatment outcome. In Group II, there was significantly high (P < 0.05) patient satisfaction index as compared to Group I. Group II reported 100% 'cure' (absence of hemorrhoidal masses even on proctoscopy) of internal hemorrhoidal prolapse as against 80

  19. A comparative study of Barron's rubber band ligation with Kshar Sutra ligation in hemorrhoids.

    PubMed

    Singh, Rakhi; Arya, Ramesh C; Minhas, Satinder S; Dutt, Anil

    2010-04-01

    Despite a long medical history of identification and treatment, hemorrhoids still pose a challenge to the medical fraternity in terms of finding satisfactory cure of the disease. In this study, Kshar Sutra Ligation (KSL), a modality of treatment described in Ayurveda, was compared with Barron's Rubber Band Ligation (RBL) for grade II and grade III hemorrhoids. This study was conducted in 20 adult patients of either sex with grade II and grade III hemorrhoids at two different hospitals. Patients were randomly allotted to two groups of 10 patients each. Group I patients underwent RBL, whereas patients of group II underwent KSL. Guggul-based Apamarga Kshar Sutra was prepared according to the principles laid down in ancient Ayurvedic texts and methodology standardized by IIIM, Jammu and CDRI, Lucknow. Comparative assessment of RBL and KSL was done according to 16 criteria. Although the two procedures were compared on 15 criteria, treatment outcome of grade II and grade III hemorrhoids was decided chiefly on the basis of patient satisfaction index (subjective criterion) and ability of each procedure to deal with prolapse of internal hemorrhoidal masses (objective criterion): Findings in each case were recorded over a follow-up of four weeks (postoperative days 1, 3, 7, 15 and 30). Statistical analysis was done using Student's t test for parametric data and Chi square test & Mann-Whitney test for non-parametric data. P < 0.05 was considered significant. RBL had the advantages of being an OPD procedure requiring no anesthesia and was attended by significantly lesser postoperative recumbency (P < 0.001 ) and significantly lesser pain (P < 0.005 on day 1) as compared to KSL. However, Group II (KSL) scored better in terms of treatment outcome. In Group II, there was significantly high (P < 0.05) patient satisfaction index as compared to Group I. Group II reported 100% 'cure' (absence of hemorrhoidal masses even on proctoscopy) of internal hemorrhoidal prolapse as against 80

  20. Ectopic tubal pregnancy after hysterectomy and tubal ligation.

    PubMed

    Rosa, Marilin; Mohammadi, Amir; Monteiro, Carmela

    2009-01-01

    Posthysterectomy ectopic pregnancy is an unusual condition that may present soon after hysterectomy or several years later. Similarly, although tubal ligation is a widespread method of contraception, tubal pregnancy after tubal ligation is not common either. If any of these conditions are rare, having an ectopic pregnancy after hysterectomy and tubal ligation is even more infrequent and only one of such cases was found in our review of the literature. We describe the case of a 35-year-old patient, with history of bilateral tubal ligation and vaginal hysterectomy that looked for medical attention due to abdominal pain. A pregnancy test was positive and a transvaginal ultrasound demonstrated the presence of a gestational sac at the vaginal cuff, adjacent to the ovary. An exploratory laparotomy showed a ruptured ectopic pregnancy located in the distal portion of the left fallopian tube. The occurrence of an ectopic pregnancy several years following tubal ligation and vaginal hysterectomy is a rare phenomenon that appears to be secondary to a fistulous connection into the peritoneal cavity.

  1. Splenic Artery Embolization for the Treatment of Gastric Variceal Bleeding Secondary to Splenic Vein Thrombosis Complicated by Necrotizing Pancreatitis: Report of a Case

    PubMed Central

    Park, Eun Kyu; Hur, Young Hoe; Koh, Yang Seok

    2016-01-01

    Splenic vein thrombosis is a relatively common finding in pancreatitis. Gastric variceal bleeding is a life-threatening complication of splenic vein thrombosis, resulting from increased blood flow to short gastric vein. Traditionally, splenectomy is considered the treatment of choice. However, surgery in necrotizing pancreatitis is dangerous, because of severe inflammation, adhesion, and bleeding tendency. In the Warshaw operation, gastric variceal bleeding is rare, even though splenic vein is resected. Because the splenic artery is also resected, blood flow to short gastric vein is not increased problematically. Herein, we report a case of gastric variceal bleeding secondary to splenic vein thrombosis complicated by necrotizing pancreatitis successfully treated with splenic artery embolization. Splenic artery embolization could be the best treatment option for gastric variceal bleeding when splenectomy is difficult such as in case associated with severe acute pancreatitis or associated with severe adhesion or in patients with high operation risk. PMID:27891150

  2. Regression of esophageal varices and splenomegaly in two patients with hepatitis-C-related liver cirrhosis after interferon and ribavirin combination therapy.

    PubMed

    Lee, Soon Jae; Cho, Yoo-Kyung; Na, Soo-Young; Choi, Eun Kwang; Boo, Sun Jin; Jeong, Seung Uk; Song, Hyung Joo; Kim, Heung Up; Kim, Bong Soo; Song, Byung-Cheol

    2016-09-01

    Some recent studies have found regression of liver cirrhosis after antiviral therapy in patients with hepatitis C virus (HCV)-related liver cirrhosis, but there have been no reports of complete regression of esophageal varices after interferon/peg-interferon and ribavirin combination therapy. We describe two cases of complete regression of esophageal varices and splenomegaly after interferon-alpha and ribavirin combination therapy in patients with HCV-related liver cirrhosis. Esophageal varices and splenomegaly regressed after 3 and 8 years of sustained virologic responses in cases 1 and 2, respectively. To our knowledge, this is the first study demonstrating that complications of liver cirrhosis, such as esophageal varices and splenomegaly, can regress after antiviral therapy in patients with HCV-related liver cirrhosis.

  3. RNA-Catalyzed RNA Ligation on an External RNA Template

    NASA Technical Reports Server (NTRS)

    McGinness, Kathleen E.; Joyce, Gerald F.

    2002-01-01

    Variants of the hc ligase ribozyme, which catalyzes ligation of the 3' end of an RNA substrate to the 5' end of the ribozyme, were utilized to evolve a ribozyme that catalyzes ligation reactions on an external RNA template. The evolved ribozyme catalyzes the joining of an oligonucleotide 3'-hydroxyl to the 5'-triphosphate of an RNA hairpin molecule. The ribozyme can also utilize various substrate sequences, demonstrating a largely sequence-independent mechanism for substrate recognition. The ribozyme also carries out the ligation of two oligonucleotides that are bound at adjacent positions on a complementary template. Finally, it catalyzes addition of mononucleoside '5-triphosphates onto the '3 end of an oligonucleotide primer in a template-dependent manner. The development of ribozymes that catalyze polymerase-type reactions contributes to the notion that an RNA world could have existed during the early history of life on Earth.

  4. Splint ligation of RNA with T4 DNA ligase

    PubMed Central

    Kershaw, Christopher J.; O’Keefe, Raymond T.

    2014-01-01

    Splint ligation of RNA, whereby specific RNA molecules are ligated together, can be carried out using T4 DNA ligase and a bridging DNA oligonucleotide complementary to the RNAs. This method takes advantage of the property of T4 DNA ligase to join RNA molecules when they are in an RNA:DNA hybrid. Splint ligation is a useful tool for the introduction of modified nucleotides into RNA molecules, insertion of a radiolabel into a specific position within an RNA and for the assembly of smaller synthetic RNAs into longer RNA molecules. Such modifications enable a wide range of experiments to be carried out with the modified RNA including structural studies, co-immunoprecipitations, and the ability to map sites of RNA:RNA and RNA:protein interactions. PMID:23065567

  5. Template-Directed Ligation of Peptides to Oligonucleotides

    NASA Technical Reports Server (NTRS)

    Bruick, Richard K.; Dawson, Philip E.; Kent, Stephen BH; Usman, Nassim; Joyce, Gerald F.

    1996-01-01

    Synthetic oligonucleotides and peptides have enjoyed a wide range of applications in both biology and chemistry. As a consequence, oligonucleotide-peptide conjugates have received considerable attention, most notably in the development of antisense constructs with improved pharmacological properties. In addition, oligonucleotide-peptide conjugates have been used as molecular tags, in the assembly of supramolecular arrays and in the construction of encoded combinatorial libraries. To make these chimeric molecules more accessible for a broad range of investigations, we sought to develop a facile method for joining fully deprotected oligonucleotides and peptides through a stable amide bond linkage. Furthermore, we wished to make this ligation reaction addressable, enabling one to direct the ligation of specific oligonucleotide and peptide components.To confer specificity and accelerate the rate of the reaction, the ligation process was designed to be dependent on the presence of a complementary oligonucleotide template.

  6. Development of an Improved Animal Model of Overactive Bladder: Transperineal Ligation versus Transperitoneal Ligation in Male Rats

    PubMed Central

    Kim, Woo Hyun; Bae, Woong Jin; Park, Jung Woo; Choi, Jin Bong; Kim, Su Jin; Cho, Hyuk Jin; Ha, U Syn; Hong, Sung Hoo; Lee, Ji Youl; Hwang, Sung Yeoun

    2016-01-01

    Purpose We compared a transperineal ligation model and a transperitoneal ligation model in male rats to determine which animal model of overactive bladder (OAB) was more useful based on cystometrography, estimations of oxidative stress, and measurements of pro-inflammatory cytokine levels. Materials and Methods Male rats were randomly divided into three groups (n=15 in each): the control group, the transperineal ligation group, and the transperitoneal ligation group. Four weeks after the ligation procedure, cystometrography was performed and oxidative stress, pro-inflammatory cytokine levels, and histologic changes were evaluated. Oxidative stress was assessed by measuring 8-hydroxy-20-deoxyguanosine and superoxide dismutase, and pro-inflammatory cytokine activity was investigated by measuring levels of interleukin (IL)-6, IL-8, and tumor necrosis factor-α. Results The transperineal model led to results similar to those observed for the transperitoneal model, namely (1) increased voiding frequency and reductions in the non-voiding contraction interval and the maximal vesical pressure, (2) increased levels of oxidative stress markers, (3) increased pro-inflammatory cytokine levels, and (4) fibrotic changes in the bladder tissue. Conclusions We suggest that the transperineal procedure can be used as an alternative OAB model in male rats. PMID:27574597

  7. Butelase-mediated cyclization and ligation of peptides and proteins.

    PubMed

    Nguyen, Giang K T; Qiu, Yibo; Cao, Yuan; Hemu, Xinya; Liu, Chuan-Fa; Tam, James P

    2016-10-01

    Enzymes that catalyze efficient macrocyclization or site-specific ligation of peptides and proteins can enable tools for drug design and protein engineering. Here we describe a protocol to use butelase 1, a recently discovered peptide ligase, for high-efficiency cyclization and ligation of peptides and proteins ranging in size from 10 to >200 residues. Butelase 1 is the fastest known ligase and is found in pods of the common medicinal plant Clitoria ternatea (also known as butterfly pea). It has a very simple C-terminal-specific recognition motif that requires Asn/Asp (Asx) at the P1 position and a dipeptide His-Val at the P1' and P2' positions. Substrates for butelase-mediated ligation can be prepared by standard Fmoc (9-fluorenylmethyloxycarbonyl) chemistry or recombinant expression with the minimal addition of this tripeptide Asn-His-Val motif at the C terminus. Butelase 1 achieves cyclizations that are 20,000 times faster than those of sortase A, a commonly used enzyme for backbone cyclization. Unlike sortase A, butelase is traceless, and it can be used for the total synthesis of naturally occurring peptides and proteins. Furthermore, butelase 1 is also useful for intermolecular ligations and synthesis of peptide or protein thioesters, which are versatile activated intermediates necessary for and compatible with many chemical ligation methods. The protocol describes steps for isolation and purification of butelase 1 from plant extract using a four-step chromatography procedure, which takes ∼3 d. We then describe steps for intramolecular cyclization, intermolecular ligation and butelase-mediated synthesis of protein thioesters. Butelase reactions are generally completed within minutes and often achieve excellent yields.

  8. Treatment of spontaneous tumours by temporary local ligation

    PubMed Central

    Allen, Frederick M.; Kaplan, Martin M.; Meranze, David R.; Gradess, Morton

    1960-01-01

    Previous work in some human cases and in laboratory animals has indicated that temporary local ligation of spontaneous tumours has a selective destructive effect on these tumours, with only temporary inflammation resulting in normal tissues. In the experiments described in this paper, 49 spontaneous accessible tumours in dogs were treated by this method, with periods of ligation of from 4 to 11 hours. Success, as measured by selective necrosis of tumour tissue as compared with normal tissue, was achieved in 29 out of 41 benign tumours, including lipomas, angiomas, adenomas and mixed mammary tumours. Treatment failures were encountered in two cases each of papillomas and fibromas, six mixed mammary tumours and two testicular tumours. Total necrosis of tumour cells occurred in all eight malignant tumours encountered in this series. The outstanding feature was the specific destruction of tumour tissue by a bodily process without participation of any outside agent. Emphasis was placed on an adequate inflammatory response following temporary anoxia, although a precise definition of this inflammation could not be offered. Post-ligation bacterial multiplication, which may be expected to occur in necrotic tumour tissue, is considered to be a secondary effect rather than a possible primary cause of regression and disappearance of the tumour. If ligation treatment can be shown to be successful for a particular type of tumour, it may be possible to apply it to human patients for the treatment of areas not amenable to surgery. The results reported here warrant new experimental approaches to the study of neoplasms at the cellular level to define more precisely the anoxic and inflammatory processes involved in the selective lethal effect on tumour tissues; and the authors suggest that trials should be undertaken of combinations of chemotherapy or irradiation with ligation to reduce ligation time and extend the possible benefits. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7

  9. Alternative Okazaki Fragment Ligation Pathway by DNA Ligase III.

    PubMed

    Arakawa, Hiroshi; Iliakis, George

    2015-06-23

    Higher eukaryotes have three types of DNA ligases: DNA ligase 1 (Lig1), DNA ligase 3 (Lig3) and DNA ligase 4 (Lig4). While Lig1 and Lig4 are present in all eukaryotes from yeast to human, Lig3 appears sporadically in evolution and is uniformly present only in vertebrates. In the classical, textbook view, Lig1 catalyzes Okazaki-fragment ligation at the DNA replication fork and the ligation steps of long-patch base-excision repair (BER), homologous recombination repair (HRR) and nucleotide excision repair (NER). Lig4 is responsible for DNA ligation at DNA double strand breaks (DSBs) by the classical, DNA-PKcs-dependent pathway of non-homologous end joining (C-NHEJ). Lig3 is implicated in a short-patch base excision repair (BER) pathway, in single strand break repair in the nucleus, and in all ligation requirements of the DNA metabolism in mitochondria. In this scenario, Lig1 and Lig4 feature as the major DNA ligases serving the most essential ligation needs of the cell, while Lig3 serves in the cell nucleus only minor repair roles. Notably, recent systematic studies in the chicken B cell line, DT40, involving constitutive and conditional knockouts of all three DNA ligases individually, as well as of combinations thereof, demonstrate that the current view must be revised. Results demonstrate that Lig1 deficient cells proliferate efficiently. Even Lig1/Lig4 double knockout cells show long-term viability and proliferate actively, demonstrating that, at least in DT40, Lig3 can perform all ligation reactions of the cellular DNA metabolism as sole DNA ligase. Indeed, in the absence of Lig1, Lig3 can efficiently support semi-conservative DNA replication via an alternative Okazaki-fragment ligation pathway. In addition, Lig3 can back up NHEJ in the absence of Lig4, and can support NER and HRR in the absence of Lig1. Supporting observations are available in less elaborate genetic models in mouse cells. Collectively, these observations raise Lig3 from a niche-ligase to a

  10. RNA self-ligation: from oligonucleotides to full length ribozymes.

    PubMed

    Gwiazda, Slawomir; Salomon, Kristina; Appel, Bettina; Müller, Sabine

    2012-07-01

    The RNA-world-theory is one possible explanation of how life on earth has evolved. In this context it is of high interest to search for molecular systems, capable of self-organization into structures with increasing complexity. We have engineered a simple catalytic system in which two short RNA molecules can catalyze their own ligation to form a larger RNA construct. The system is based on the hairpin ribozyme using a 2',3'-cyclophosphate as activated species for ligation. 2',3'-cyclic phosphates can be easily formed and occur in many natural systems, thus being superior candidates for activated building blocks in RNA world scenarios.

  11. Sequelae of tubal ligation: an analysis of 75 consecutive hysterectomies.

    PubMed

    Stock, R J

    1984-10-01

    Seventy-five consecutive patients undergoing hysterectomy subsequent to elective sterilization were studied regarding the occurrence of the post-tubal-ligation syndrome of pelvic pain and/or menorrhagia. Twenty patients were clinically considered to have the syndrome. In none of the patients operated on specifically for menstrual abnormalities could the findings be remotely attributed to the sterilization procedure. Five of the 20 patients had pelvic varicosities and one had pelvic adhesions that may have been a consequence of previous sterilization and conceivably the cause for the pelvic pain for which the patients were undergoing hysterectomy. I question the legitimacy of the post-tubal-ligation syndrome as a reason for hysterectomy.

  12. Endocrine profile of patients with post-tubal-ligation syndrome.

    PubMed

    Hargrove, J T; Abraham, G E

    1981-07-01

    The endocrine profile of the midluteal phase was assessed in 29 patients with the post-tubal-ligation syndrome, consisting of pain, bleeding and premenstrual tension. Compared to normal controls, the patients had a high serum estradiol and a low serum progesterone level. This abnormal luteal function may be responsible for the symptoms observed and may also explain the failure to conceive following successful reversal of tubal ligation. It is recommended that patients seeking sterilization reversal be screened for abnormal luteal function preoperatively. Selection of sterilization procedures that minimize alteration in luteal function should be given high priority.

  13. Esophagogastric devascularization and transection for bleeding esophageal varices: first case presentation.

    PubMed

    Manzano-Trovamala, F J; Guttierrez, R L; Marquez, G M; Garcia, R A; Christen, J J; Guerrero, M G

    1996-08-01

    We present the first case of esophagogastric devascularization and esophagogastric transection using a stapler through laparoscopic surgery. The procedure was performed in a 71-year-old diabetic woman with alcoholic liver cirrhosis (Child-Pugh B class), portal hypertension, bleeding grade III esophageal varices, and a previous bleeding episode. The surgical technique was carried out without problems, and the patient had an excellent postoperative condition. Esophagogastric devascularization with esophageal transection using a stapler through laparoscopic surgery is a feasible technique that accomplishes the same and all objectives of the open procedure. Operative time in both methods is the same, whereas surgical trauma, inmunologic depletion, amount of transfused blood, pain, use of analgesics, and hospital stay are reduced in the laparoscopic technique.

  14. Sequence fidelity of a template-directed PNA-ligation reaction.

    PubMed

    Mattes, A; Seitz, O

    2001-10-21

    The ligation method and an appended duplex-stabilizing dye affect both yield and sequence selectivity of a template-controlled PNA-ligation. The highest selectivity was obtained with a peptide condensation that formed an abasic site.

  15. Optimization of ligation reaction conditions in gene synthesis.

    PubMed

    Theriault, N Y; Carter, J B; Pulaski, S P

    1988-05-01

    Several phosphorylation, annealing and ligation reaction conditions have been investigated for the enzymatic assembly of genes of interest. The use of longer oligodeoxyribonucleotides (40-60 bases long) also improved the enzymatic reaction. Furthermore, the use of longer oligonucleotides and the elimination of long stretches of G's or C's lowered the mutation rate.

  16. Magnetic Ligation Method for Quantitative Detection of MicroRNAs

    PubMed Central

    Liong, Monty; Im, Hyungsoon; Majmudar, Maulik D.; Aguirre, Aaron D.; Sebas, Matthew; Lee, Hakho; Weissleder, Ralph

    2014-01-01

    A magnetic ligation method is utilized for the detection of microRNAs amongst a complex biological background without polymerase chain reaction or nucleotide modification. The sandwich probes assay can be adapted to analyze a panel of microRNAs associated with cardiovascular diseases in heart tissue samples. PMID:24532323

  17. Click nucleic acid ligation: applications in biology and nanotechnology.

    PubMed

    El-Sagheer, Afaf H; Brown, Tom

    2012-08-21

    Biochemical strategies that use a combination of synthetic oligonucleotides, thermostable DNA polymerases, and DNA ligases can produce large DNA constructs up to 1 megabase in length. Although these ambitious targets are feasible biochemically, comparable technologies for the chemical synthesis of long DNA strands lag far behind. The best available chemical approach is the solid-phase phosphoramidite method, which can be used to assemble DNA strands up to 150 bases in length. Beyond this point, deficiencies in the chemistry make it impossible to produce pure DNA. A possible alternative approach to the chemical synthesis of large DNA strands is to join together carefully purified synthetic oligonucleotides by chemical methods. Click ligation by the copper-catalyzed azide-alkyne (CuAAC) reaction could facilitate this process. In this Account, we describe the synthesis, characterization, and applications of oligonucleotides prepared by click ligation. The alkyne and azide oligonucleotide strands can be prepared by standard protocols, and the ligation reaction is compatible with a wide range of chemical modifications to DNA and RNA. We have employed click ligation to synthesize DNA constructs up to 300 bases in length and much longer sequences are feasible. When the resulting triazole linkage is placed in a PCR template, various DNA polymerases correctly copy the entire base sequence. We have also successfully demonstrated both in vitro transcription and rolling circle amplification through the modified linkage. This linkage has shown in vivo biocompatibility: an antibiotic resistance gene containing triazole linkages functions in E. coli . Using click ligation, we have synthesized hairpin ribozymes up to 100 nucleotides in length and a hammerhead ribozyme with the triazole linkage located at the substrate cleavage site. At the opposite end of the length scale, click-ligated, cyclic mini-DNA duplexes have been used as models to study base pairing. Cyclic duplexes have

  18. N-butyl-2-cyanoacrylate, iso-amyl-2-cyanoacrylate and hypertonic glucose with 72% chromated glycerin in gastric varices

    PubMed Central

    Elwakil, Reda; Montasser, Mohamed Fawzy; Abdelhakam, Sara M; Ibrahim, Wesam A

    2015-01-01

    AIM: To compare n-butyl-2-cyanoacrylate, iso-amyl-2-cyanoacrylate and a mixture of 72% chromated glycerin with hypertonic glucose solution in management of gastric varices. METHODS: Ninety patients with gastric varices presented to Endoscopy Unit of Ain Shams University Hospital were included. They were randomly allocated into three groups; each group included 30 patients treated with intravariceal sclerosant injections in biweekly sessions till complete obturation of gastric varices; Group I (n-butyl-2-cyanoacrylate; Histoacryl®), Group II (iso-amyl-2-cyanoacrylate; Amcrylate®) and Group III (mixture of 72% chromated glycerin; Scleremo® with glucose solution 25%). All the procedures were performed electively without active bleeding. Recruited patients were followed up for 3 mo. RESULTS: 26% of Scleremo group had bleeding during puncture vs 3.3% in each of the other two groups with significant difference, (P < 0.05). None of Scleremo group had needle obstruction vs 13.3% in each of the other two groups with no significant difference, (P > 0.05). Rebleeding occurred in 13.3% of Histoacryl and Amcrylate groups vs 0% in Scleremo group with no significant difference. The in hospital mortality was 6.6% in both Histoacryl and Amcrylate groups, while it was 0% in Scleremo group with no significant difference. In the first and second sessions, the amount of Scleremo needed for obturation was significantly high, while the amount of Histoacryl was significantly low. Scleremo was the less costly of the two treatments. CONCLUSION: All used sclerosant substances showed efficacy and success in management of gastric varices with no significant differences except in total amount, cost and bleeding during puncture. PMID:25901221

  19. An Unusual Case of Gastrointestinal Bleeding from Isolated Gallbladder Varices in a Patient with Pancreatic Cancer Complicated by Portal Biliopathy

    PubMed Central

    Kubachev, Kubach; Abdullaev, Elbrus; Zarkua, Nonna; Abdullaev, Abakar; Fokin, Artur

    2016-01-01

    Portal biliopathy is the complex of abnormalities of extrahepatic and intrahepatic bile ducts, cystic duct, and gallbladder, arising as a result of extrahepatic portal vein obstruction and noncirrhotic portal fibrosis, which can be caused by coagulopathies, tumors, inflammation, postoperative complications, dehydration, and neonatal umbilical vein catheterization. We report a case of a 55-year-old male patient with the history of pancreatic cancer and cholecystoenteric anastomosis presenting with gastrointestinal bleeding from gallbladder varices via the anastomosis. PMID:27800195

  20. Application of an omonasteine ligation strategy for the total chemical synthesis of the BRD7 bromodomain.

    PubMed

    Van de Vijver, Pieter; Scheer, Liesbeth; van Beijnum, Judy; Griffioen, Arjan; Hackeng, Tilman M

    2012-09-28

    The use of omonasteine (Omo) in sequential peptide ligation strategies extends the scope of homocysteine (Hcy) ligation to longer, methionine-rich proteins. Hcy-to-Omo conversion can be performed on-resin, while the Omo-to-Hcy deprotection can be performed in situ after peptide ligation. This strategy was successfully applied in the synthesis of the BRD7 bromodomain.

  1. Invasive and non-invasive techniques for detecting portal hypertension and predicting variceal bleeding in cirrhosis: a review.

    PubMed

    Zardi, Enrico Maria; Di Matteo, Francesco Maria; Pacella, Claudio Maurizio; Sanyal, Arun J

    2014-02-01

    Portal hypertension is a severe syndrome that may derive from pre-sinusoidal, sinusoidal, and post-sinusoidal causes. As a consequence, several complications (i.e. ascites, oesophageal varices) may develop. In sinusoidal portal hypertension, hepatic venous pressure gradient (HVPG) is a reliable method for defining the grade of portal pressure, establishing the effectiveness of the treatment, and predicting the occurrence of complications; however, some questions exist regarding its ability to discriminate bleeding from non-bleeding varices in cirrhotic patients. Other imaging techniques (transient elastography, endoscopy, endosonography, and duplex Doppler sonography) for assessing causes and complications of portal hypertensive syndrome are available and may be valuable for the management of these patients. In this review, we evaluate invasive and non-invasive techniques currently employed to obtain a clinical prediction of deadly complications, such as variceal bleeding in patients affected by sinusoidal portal hypertension, in order to create a diagnostic algorithm to manage them. Again, HVPG appears to be the reference standard to evaluate portal hypertension and monitor the response to treatment, but its ability to predict several complications and support management decisions might be further improved through the diagnostic combination with other imaging techniques.

  2. Endoscopic management of bleeding gastric varices with N-butyl, 2-cyanoacrylate glue injection in children with non-cirrhotic portal hypertension

    PubMed Central

    Poddar, Ujjal; Borkar, Vibhor; Yachha, Surender Kumar; Srivastava, Anshu

    2016-01-01

    Background and study aims: In view of the paucity of literature, we carried out this audit to evaluate the safety and efficacy of N- butyl, 2-cynoacrylate glue injection therapy in secondary prophylaxis of gastric varices in children. Patients and methods: Consecutive children (≤ 18 years) with non-cirrhotic portal hypertension who presented with bleeding from gastric varices and who had undergone cyanoacrylate glue injection therapy were included. They were evaluated for safety, efficacy and complications. Their long-term outcomes and follow-up were recorded. Results: Over 11 years, 28 children with median age 13 (range, 8 to 18) years (68 % boys), underwent cyanoacrylate glue injection for bleeding gastric varices. In 25 (89 %) cases, extrahepatic portal venous obstruction was the etiology and isolated gastric varices were the source of the bleeding. Primary and secondary gastric variceal bleeding was seen in 11 (39 %) and 17 (61 %) children, respectively. A total 36 sessions with median volume of 2 (range, 1 – 5) mL of glue injections were required (2 sessions in 8 children). Hemostasis was achieved in all and 57 % had gastric variceal obliteration. Two children had early (< 1 month) rebleeding and 2 children had late rebleeding. One child had gastric ulcer. Over a median follow-up of 24 (8 – 98) months, 14 children underwent surgery (12 porto-systemic shunt), 2 were lost to follow-up, 1 died and there was no recurrence of bleeding in the remaining 11. Conclusions: Cyanoacrylate glue injection is highly effective mode of secondary prophylaxis of bleeding gastric varices in children with non-cirrhotic portal hypertension. Rebleeding occurred in 14 % but treatment-related complications were uncommon. However, a large controlled clinical trial is required to confirm our findings. PMID:27757413

  3. Endoscopic management of bleeding gastric varices with N-butyl, 2-cyanoacrylate glue injection in children with non-cirrhotic portal hypertension.

    PubMed

    Poddar, Ujjal; Borkar, Vibhor; Yachha, Surender Kumar; Srivastava, Anshu

    2016-10-01

    Background and study aims: In view of the paucity of literature, we carried out this audit to evaluate the safety and efficacy of N- butyl, 2-cynoacrylate glue injection therapy in secondary prophylaxis of gastric varices in children. Patients and methods: Consecutive children (≤ 18 years) with non-cirrhotic portal hypertension who presented with bleeding from gastric varices and who had undergone cyanoacrylate glue injection therapy were included. They were evaluated for safety, efficacy and complications. Their long-term outcomes and follow-up were recorded. Results: Over 11 years, 28 children with median age 13 (range, 8 to 18) years (68 % boys), underwent cyanoacrylate glue injection for bleeding gastric varices. In 25 (89 %) cases, extrahepatic portal venous obstruction was the etiology and isolated gastric varices were the source of the bleeding. Primary and secondary gastric variceal bleeding was seen in 11 (39 %) and 17 (61 %) children, respectively. A total 36 sessions with median volume of 2 (range, 1 - 5) mL of glue injections were required (2 sessions in 8 children). Hemostasis was achieved in all and 57 % had gastric variceal obliteration. Two children had early (< 1 month) rebleeding and 2 children had late rebleeding. One child had gastric ulcer. Over a median follow-up of 24 (8 - 98) months, 14 children underwent surgery (12 porto-systemic shunt), 2 were lost to follow-up, 1 died and there was no recurrence of bleeding in the remaining 11. Conclusions: Cyanoacrylate glue injection is highly effective mode of secondary prophylaxis of bleeding gastric varices in children with non-cirrhotic portal hypertension. Rebleeding occurred in 14 % but treatment-related complications were uncommon. However, a large controlled clinical trial is required to confirm our findings.

  4. Addition of HOBt improves the conversion of thioester-Amine chemical ligation.

    PubMed

    Todorovski, Toni; Suñol, David; Riera, Antoni; Macias, Maria J

    2015-11-01

    The syntheses of large peptides and of those containing non-natural amino acids can be facilitated by the application of convergent approaches, dissecting the native sequence into segments connected through a ligation reaction. We describe an improvement of the ligation protocol used to prepare peptides and proteins without cysteine residues at the ligation junction. We have found that the addition of HOBt to the ligation, improves the conversion of the ligation reaction without affecting the epimerization rate or chemoselectivity, and it can be efficiently used with peptides containing phosphorylated amino acids.

  5. [Clinical value of acoustic radiation force impulse technique to predict esophageal and gastric varices in patients with biliary atresia].

    PubMed

    Zhang, G Y; Tang, Y; Niu, N N; Wu, H T

    2017-02-21

    Objective: To investigate the clinical value of acoustic radiation force impulse (ARFI)technique in predicting esophageal and gastric varices in patients with biliary atresia after Kasai portoenterostomy. Methods: A total of 42 patients with biliary atresia after Kasai portoenterostomy were collected from September 2015 to May 2016 in Tianjin First Central Hospital.ARFI technique was used to measure the stiffness of liver and spleen, and 28 healthy children as control.According to the result of CT examination , patients with biliary atresia were divided into two groups , twenty-three patients with esophageal and gastric varices(A group) and nineteen patients without esophageal and gastric varices (B group), Comparing the difference of liver and spleen stiffness between the two groups.The ROC curve analysis was carried out to test the diagnostic power of effective parameter. Results: The ARFI value of liver (2.98±0.80) m/s and spleen (3.00±0.33) m/s of patients with biliary atresia was significantly higher than that of control group((1.10±0.16) m/s, (2.12±0.32) m/s), the differences had statistical significance (both P<0.01). Between group A and group B, the spleen ARFI value of group A(3.16±0.26) m/s was higher than group B(2.83±0.32) m/s, the difference had statistical significance (P<0.01), whereas there was no statistical difference of liver ARFI value between two group((2.93±0.65), (3.02±0.96) m/s)(P>0.05). The cut-off ARFI value of spleen to diagnose esophageal and gastric varices in biliary atresia was 3.02 m/s, and the biggest area under the ROC curve, sensitivity, and specificity were 0.81, 78.6% and 84.5%, respectively. Conclusion: ARFI can be used as a noninvasive method to predict the presence of esophageal and gastric varices in patients with biliary atresia after Kasai portoenterostomy.

  6. Percutaneous transhepatic obliteration and percutaneous transhepatic sclerotherapy for intractable hepatic encephalopathy and gastric varices improves the hepatic function reserve.

    PubMed

    Ishikawa, Toru; Imai, Michitaka; Ko, Masayoshi; Sato, Hiroki; Nozawa, Yujiro; Sano, Tomoe; Iwanaga, Akito; Seki, Keiichi; Honma, Terasu; Yoshida, Toshiaki

    2017-01-01

    Percutaneous transhepatic obliteration (PTO) and percutaneous transhepatic sclerotherapy (PTS) are widely performed as an emergency measure in cases of variceal hemorrhage and intractable hepatic encephalopathy. The PTO/PTS technique is capable of directly blocking the blood supply in cases in which balloon-occluded retrograde transvenous obliteration (B-RTO) is not effective, or in cases with complicated collateral flow. Although PTO/PTS is not currently the first choice due to the invasiveness of transhepatic puncture, this procedure can modify the blood flow in an antegrade manner. The present study examined the changes in hepatic function reserve following PTO/PTS for intractable hepatic encephalopathy and/or gastric varices. In total, the study included 37 patients (mean age, 61.75±12.77 years; age range, 32-88 years; male to female ratio, 23:14) with a variety of gastrorenal shunts, or B-RTO-intractable hepatic encephalopathy and gastric varices without gastrorenal shunts. The patients underwent PTO/PTS by embolizing a microcoil or injection of a sclerosing agent (5% ethanolamine oleate iopamidol). Alterations in hepatic function reserve prior to and following the procedure were compared. The patients were treated for hepatic encephalopathy in 11 patients, gastric varices in 19 patients, and both conditions in 7 patients. The results indicated that the blood ammonia level improved from 135.76±75.23 mg/dl to 88.00±42.16 and 61.81±33.75 mg/dl at 3 and 6 months after therapy, respectively. In addition, the Child-Pugh score improved from 8.48±2.01 prior to therapy to 7.70±1.84 and 7.22±2.01 at 3 and 6 months after the procedure, respectively. Although there was a concern that PTO/PTS may cause complications due to an increase in portal venous pressure (PVP) arising from shunt occlusion, no severe complications were observed. In conclusion, for patients with various gastrorenal shunts or those with B-RTO-intractable hepatic encephalopathy and gastric

  7. Spinal Epidural Varices, a great Mimic of Intervertebral Disc Prolapse - A Case Series

    PubMed Central

    V, Raghavendra; Haridas, Papanaik; Kumar, Anand; K, Ajith

    2014-01-01

    Introduction: Epidural venous plexus enlargement, presenting with low back pain and radiculopathy, is an uncommon cause of nerve roots impingement. This condition commonly mimics a herniated nucleus pulposus radiologically. The radiological diagnosis is often missed and the diagnosis is made during the surgery. We are hereby presenting 2 such cases of epidural varices mimicking intervertebral disc prolapse with lumbar radiculopathy. Case Report: Case 1: 43 yr old female presented with acute exacerbation of low back ache and significant right L5–S1 radiculopathy without neurological deficit. MRI reported as L5-S1 disc prolapse. Intra-operatively engorged dilated epidural vein seen compressing S1 nerve root. Associated Disc bulge removed and Coagulative ablation of the dilated epidural vein was performed Case 2: 45 year old male manual labourer presented with backache with left sided sciatica since 8 months, increased in severity since past 1month associated with sensory blunting in L5 and S1 dermatomes. Neurologic examination revealed normal muscle power in his lower extremities. Sensations was blunted in L5 and S1 dermatomes. MRI was reported as L5-S1 disc prolapsed compressing left S1 nerve root. Decompression of the L5–S1 intervertebral space was performed through a left –sidelaminotomy. Large, engorged serpentine epidural veins was found in the axilla of S1 nerve root, compressing it. Coagulative ablation of the dilated epidural vein was performed. Retrospectively, features of epidural varices were noted in the preoperative magnetic resonance imaging scans. Both patients had significant improvement in radiculopathy immediate postoperatively, and sensory symptoms resolved over the next 6 weeks in second case. At recent follow up, both patients had significant relief of symptoms and no recurrent radicular symptoms. Conclusion: An abnormal dilated epidural venous plexus that mimics a herniated lumbar disc is a rare entity. This pathology should be always kept

  8. Mortality and rebleeding following variceal haemorrhage in liver cirrhosis and periportal fibrosis

    PubMed Central

    Mohammed, Sara Elfadil Abbas; Abdo, Abdelmunem Eltayeb; Mudawi, Hatim Mohamed Yousif

    2016-01-01

    AIM To investigate mortality and rebleeding rate and identify associated risk factors at 6 wk and 5 d following acute variceal haemorrhage in patients with liver cirrhosis and schistosomal periportal fibrosis. METHODS This is a prospective study conducted during the period from March to December 2014. Patients with portal hypertension presenting with acute variceal haemorrhage secondary to either liver cirrhosis (group A) or schistosomal periportal fibroses (group B) presenting within 24 h of the onset of the bleeding were enrolled in the study and followed for a period of 6 wk. Analysis of data was done by Microsoft Excel and comparison between groups was done by Statistical Package of Social Sciences version 20 to calculate means and find the levels of statistical differences and define the mortality rates, the P value of < 0.05 was considered to be significant. RESULTS A total of 94 patients were enrolled in the study. Thirty-two patients (34%) had liver cirrhosis (group A) and 62 (66%) patients had periportal fibrosis (group B). Mortality: The 6-wk and 5-d mortality were 53% and 16% respectively in group A compared to 10% and 0% in group B (P value < 0.000 and < 0.004). In group A; a Child-Turcotte-Pugh class C and rebleeding within 5 d were significantly associated with 5-d mortality (P value < 0.029 and < 0.049 respectively) and Child- Turcotte-Pugh class C was also a significant risk factor for 6-wk mortality (P value < 0.018). In group B; mortality was significantly associated with rebleeding within the 6-wk follow-up period and requirement for blood transfusion on admission (P value < 0.005 and < 0.049). Rebleeding: The 6-wk and 5-d rebleeding rate in group A were 56% and 25% respectively compared to 32% and 3% in group B (P value < 0.015 and < 0.002). Clinical presentation with encephalopathy was a significant risk factor for 5 d rebleeding in group A (P value < 0.005) while grade III periportal fibrosis and requirement for blood transfusion on admission

  9. Model-guided ligation strategy for optimal assembly of DNA libraries.

    PubMed

    Ng, Daphne T W; Sarkar, Casim A

    2012-10-01

    DNA ligation is essential to many molecular biology manipulations, but this reaction is often carried out by following generic guidelines or by trial and error. Maximizing the desired ligation product is especially important in DNA library construction for directed evolution experiments since library diversity is directly affected by ligation efficiency. Here, we suggest that display vectors that rely on Type IIP restriction sites for cloning should be redesigned to utilize Type IIS restriction sites instead because ligation yield is significantly improved: we observed up to 15- and 2.6-fold increases in desired products for circular and linear ligation reactions, respectively. To guide ligation optimization more rationally, we developed an easily parameterized thermodynamic model that predicts product distributions based on input DNA concentrations and free energies of the ligation events. We applied this model to study ligation reactions using a ribosome display vector redesigned with Type IIS restriction sites (pRDV2). We computationally predicted and experimentally validated the relative abundance of various products in three-piece linear ligations as well as the extent of transformation from vector-insert circular ligations. Based on our results, we provide general insights into ligation and we outline guidelines for optimizing this reaction for both in vivo and in vitro display methodologies.

  10. Acute salivary gland hypofunction in the duct ligation model in the absence of inflammation

    PubMed Central

    Correia, PN; Carpenter, GH; Osailan, SM; Paterson, KL; Proctor, GB

    2008-01-01

    Objective The commonly associated aetiology of salivary gland inflammation and salivary hypofunction has led to the widely held belief that inflammation causes salivary gland hypofunction. Indeed, our own recent study seemed to support this contention. Here, we tested the hypothesis that, in an acute duct ligation model, eliminating inflammation the submandibular gland would recover normal function. Materials and methods Ligation of the rat submandibular gland excretory duct for 24 h was used to induce inflammation and salivary gland hypofunction. A group of duct ligated rats was compared with a second group given dexamethasone, on the day of duct ligation. Twenty-four hours later salivary gland function was assessed and salivary glands were collected. Results Histology and myeloperoxidase activity assay revealed a profound decrease in inflammatory cell infiltration of ligated glands from rats given dexamethasone, compared with ligated glands in the absence of dexamethasone. Salivary flow rate evoked by methacholine was decreased (P < 0.01) by approximately 56% (ligated vs control, 79 ± 9 μl min−1 g−1vs 177 ± 11 μl min−1 g−1) and salivary flow from ligated dexamethasone-treated and ligated glands was similar. Conclusion Despite eliminating the inflammatory reaction in the ligated gland, salivary hypofunction was not reversed, suggesting that other mechanisms must be at work in the ligation-induced salivary hypofunction. PMID:18221457

  11. Critical evaluation and rate constants of chemoselective ligation reactions for stoichiometric conjugations in water.

    PubMed

    Saito, Fumito; Noda, Hidetoshi; Bode, Jeffrey W

    2015-04-17

    Chemoselective ligation reactions have contributed immensely to the development of organic synthesis and chemical biology. However, the ligation of stoichiometric amounts of large molecules for applications such as protein-protein conjugates is still challenging. Conjugation reactions need to be fast enough to proceed under dilute conditions and chemoselective in the presence of unprotected functional groups; the starting materials and products must be stable under the reaction conditions. To compare known ligation reactions for their suitability under these conditions, we determined the second-order rate constants of ligation reactions using peptide substrates with unprotected functional groups. The reaction conditions, the chemoselectivity of the reactions, and the stability of the starting materials and products were carefully evaluated. In some cases, the stability could be improved by modifying the substrate structure. These data obtained under the ligation conditions provide a useful guide to choose an appropriate ligation reaction for synthesis of large molecules by covalent ligation reactions of unprotected substrates in water.

  12. The Fidelity of Template-Directed Oligonucleotide Ligation and the Inevitability of Polymerase Function

    NASA Astrophysics Data System (ADS)

    James, Kenneth D.; Ellington, Andrew D.

    1999-08-01

    The first living systems may have employed template-directed oligonucleotide ligation for replication. The utility of oligonucleotide ligation as a mechanism for the origin and evolution of life is in part dependent on its fidelity. We have devised a method for evaluating ligation fidelity in which ligation substrates are selected from random sequence libraries. The fidelities of chemical and enzymatic ligation are compared under a variety of conditions. While reaction conditions can be found that promote high fidelity copying, departure from these conditions leads to error-prone copying. In particular, ligation reactions with shorter oligonucleotide substrates are less efficient but more faithful. These results support a model for origins in which there was selective pressure for template-directed oligonucleotide ligation to be gradually supplanted by mononucleotide polymerization.

  13. Click chemistry for rapid labeling and ligation of RNA.

    PubMed

    Paredes, Eduardo; Das, Subha R

    2011-01-03

    The copper(I)-promoted azide-alkyne cycloaddition reaction (click chemistry) is shown to be compatible with RNA (with free 2'-hydroxyl groups) in spite of the intrinsic lability of RNA. RNA degradation is minimized through stabilization of the Cu(I) in aqueous buffer with acetonitrile as cosolvent and no other ligand; this suggests the general possibility of "ligandless" click chemistry. With the viability of click chemistry validated on synthetic RNA bearing "click"-reactive alkynes, the scope of the reaction is extended to in-vitro-transcribed or, indeed, any RNA, as a click-reactive azide is incorporated enzymatically. Once clickable groups are installed on RNA, they can be rapidly click labeled or conjugated together in click ligations, which may be either templated or nontemplated. In click ligations the resultant unnatural triazole-linked RNA backbone is not detrimental to RNA function, thus suggesting a broad applicability of click chemistry in RNA biological studies.

  14. Reactions of buffers in cyanogen bromide-induced ligations.

    PubMed

    Vogel, Heike; Gerlach, Claudia; Richert, Clemens

    2013-01-01

    Rapid, template-directed ligation reactions between a phosphate-terminated oligonucleotide and an unphosphorylated reaction partner may be induced by cyanogen bromide (BrCN). Frequently, however, the reaction is low yielding, and even a large excess of the condensing agent can fail to induce quantitative conversions. In this study, we used BrCN to induce chemical primer extension reactions. Here, we report that buffers containing hydroxyl groups react with short oligodeoxynucleotides in the presence of BrCN. One stable adduct between HEPBS buffer and cytosine was characterized by mass spectrometry and NMR after HPLC purification, indicating that a side reaction occurred at this nucleobase. Further, a first example of a primer extension reaction between an unmodified oligodeoxynucleotide as primer and dGMP is reported. Together, our results shed light on the potency, as well as the drawbacks of BrCN as a highly reactive condensing reagent for the ligation of unmodified nucleic acids.

  15. Is ligation the only solution to the pyrophosphate problem?

    NASA Astrophysics Data System (ADS)

    Visscher, J.; Jongbloets, R.; Schwartz, Alan W.

    1993-12-01

    Pyrophosphate linkages are easily formed during the nonenzymatic oligomerization of activated nucleotides. They often form ‘caps’ which terminate an oligonucleotide with a 5'-5' pyrophosphate. Owing to their structural resemblance to the intermediates in enzymatic ligation reactions, it has been suggested that pyrophosphate caps might have been capable of acting as activating groups in chain elongation processes. We argue that an alternative possibility would have been the specific hydrolysis of pyrophosphates.

  16. Is ligation the only solution to the pyrophosphate problem?

    NASA Technical Reports Server (NTRS)

    Visscher, J.; Jongbloets, R.; Schwartz, Alan W.

    1993-01-01

    Pyrophosphate linkages are easily formed during the nonenzymatic oligomerization of activated nucleotides. They often form `caps' which terminate an oligonucleotide with a 5'-5' pyrophosphate. Owing to their structural resemblance to the intermediates in enzymatic ligation reactions, it has been suggested that pyrophosphate caps might have been capable of acting as activating groups in chain elongation processes. We argue that an alternative possibility would have been the specific hydrolysis of pyrophosphates.

  17. DNA hybridization and ligation for directed colloidal assembly

    NASA Astrophysics Data System (ADS)

    Shyr, Margaret

    Colloidal assembly using DNA hybridization has been pursued as a means assemble non-conventional ordered colloidal structures. However, to date it is undetermined whether DNA hybridization can be used to achieve non-FCC colloidal crystals. Using microcontact printing techniques, we have fabricated covalently bound single stranded DNA (ssDNA) two-dimensional arrays on glass surfaces, which were used to direct the assembly of complementary DNA functionalized polystyrene colloids. Two of the hallmarks of DNA hybridization, sequence specificity and thermal reversibility, were demonstrated. Due to the periodicity of these arrays, laser diffraction was used to directly monitor these structures during assembly. To demonstrate the versatility of the 2D colloidal array assembled via DNA hybridization, a catalytic DNA sequence or DNAzyme was incorporated into the colloidal array system. By tethering the enzymatic strand to the patterned glass surface and the substrate strand to polystyrene colloids, we showed that the DNAzyme could prevent the assembly of the arrays when the required Pb2+ cofactor was provided. Attempts to assemble the colloid arrays and disassemble via the Pb2+-DNAzyme induced cleavage were unsuccessful, likely due to the incomplete cleavage of the multitude of hybridized linkages between each colloid and the surface. Since DNA is not only capable of catalyzing reactions, but also capable of being reacted upon by a variety of biological enzymes, we examined the use of DNA ligase as a means to control the assembly of DNA-functionalized colloids. A three-sequence linker system was used for the hybridization mediated assembly of colloids: one sequence was tethered to the surface of the glass slide or colloids, one was tethered to another colloid surface, and the linker sequence hybridizes simultaneously to both tethered sequences. Once hybridized, the two tethered fragments can be ligated using DNA ligase, resulting in a continuous sequence tethered on one end

  18. The impact of esophagogastric varices on the prognosis of patients with hepatocellular carcinoma

    PubMed Central

    Hsieh, Wei-Yao; Chen, Ping-Hsien; Lin, I-Yen; Su, Chien-Wei; Chao, Yee-; Huo, Teh-Ia; Huang, Yi-Hsiang; Hou, Ming-Chih; Lin, Han-Chieh; Wu, Jaw-Ching

    2017-01-01

    Whether or not esophagogastric varices (EGV) could determine the outcomes of patients with hepatocellular carcinoma (HCC) is still unclear. A total of 990 treatment-naive HCC patients who received an esophagogastroduodenoscopy at the time of HCC diagnosis were retrospectively enrolled. The factors in terms of prognosis were analyzed by Cox proportional hazards model and propensity score matching analysis. Among the enrolled patients, 480 (48.5%) patients had EGV. Patients with EGV had a significantly lower cumulative 5-year survival rate than those without EGV (24.9% versus 46.4%, p < 0.001). It was confirmed by a multivariate analysis and propensity score matching analysis. Stratified by tumor stage, the patients with EGV had lower survival rates than the patients without EGVs in all Barcelona Clinic Liver Cancer stages except stage D. Moreover, the patients with EGV had lower survival rates than those without EGV, both by curative or non-curative treatment modalities. In conclusion, EGV was an independent risk factor predicting poor prognosis for the patients with HCC by multivariate analysis, propensity score matching analysis, and subgroup analysis. PMID:28209963

  19. Novel Therapeutic Strategies in the Management of Non-Variceal Upper Gastrointestinal Bleeding

    PubMed Central

    Garber, Ari; Jang, Sunguk

    2016-01-01

    Non-variceal upper gastrointestinal bleeding, the most common etiology of which is peptic ulcer disease, remains a persistent challenge despite a reduction in both its incidence and mortality. Both pharmacologic and endoscopic techniques have been developed to achieve hemostasis, with varying degrees of success. Among the pharmacologic therapies, proton pump inhibitors remain the mainstay of treatment, as they reduce the risk of rebleeding and requirement for recurrent endoscopic evaluation. Tranexamic acid, a derivative of the amino acid lysine, is an antifibrinolytic agent whose role requires further investigation before application. Endoscopically delivered pharmacotherapy, including Hemospray (Cook Medical), EndoClot (EndoClot Plus Inc.), and Ankaferd Blood Stopper (Ankaferd Health Products), in addition to standard epinephrine, show promise in this regard, although their mechanisms of action require further investigation. Non-pharmacologic endoscopic techniques use one of the following two methods to achieve hemostasis: ablation or mechanical tamponade, which may involve using endoscopic clips, cautery, argon plasma coagulation, over-the-scope clipping devices, radiofrequency ablation, and cryotherapy. This review aimed to highlight these novel and fundamental hemostatic strategies and the research supporting their efficacy. PMID:27744662

  20. Post-gastrectomy spleen enlargement and esophageal varices: Distal vs total gastrectomy

    PubMed Central

    Oida, Takatsugu; Mimatsu, Kenji; Kano, Hisao; Kawasaki, Atsushi; Kuboi, Youichi; Fukino, Nobutada; Amano, Sadao

    2010-01-01

    AIM: To study the relationship between platelet count-to-spleen diameter ratio and post-gastrectomy esophageal varices (EVs) development in patients without liver cirrhosis or hepatitis. METHODS: We retrospectively studied 92 patients who underwent gastrectomy. They were divided into 2 groups on the basis of the surgical treatment: the distal gastrectomy (DG) group and total gastrectomy (TG) group. The incidence of EVs was determined and postoperative platelet counts, spleen diameters, and platelet count-to-spleen diameter ratios were compared between the 2 groups. RESULTS: EVs were not detected during the first 6 mo after surgery in either group; however, at 12 mo after surgery, EVs were detected in 2 patients (3%) in the DG group and in 1 patient (3.6%) in the TG group; their mean platelet count-to-spleen diameter ratio was 2628 ± 409, and 2604 ± 360, respectively. CONCLUSION: Endoscopy should be performed to detect EVs when the platelet count-to-spleen diameter ratio is < 2600. PMID:20533601

  1. Increased Serum Activity of Matrix Metalloproteinase-9 in Patients with Acute Variceal Bleeding

    PubMed Central

    Kwon, Oh Sang; Jung, Hyuk Sang; Bae, Kyung Sook; Jung, Young Kul; Kim, Yeon Suk; Choi, Duck Joo; Kim, Yun Soo

    2012-01-01

    Background/Aims Matrix metalloproteinases (MMP)-2 and -9 can degrade essential components of vascular integrity. The aim of this study was to investigate the association between those MMPs and variceal bleeding (VB). Methods Fifteen controls, 12 patients with acute ulcer bleeding (UB) group, 37 patients with varix (V group), and 35 patients with acute VB group were enrolled. Serum was obtained to measure MMP-2 and -9 activity by zymogram protease assays. Results The activity levels of these compounds were compared with the controls' median value. The median MMP-9 activity was 1.0 in controls, 1.05 in the UB group, 0.43 in the V group, and 0.96 in the VB group. The level of MMP-9 activity was higher in the VB group than in the V group (p<0.001). In the VB group, there was a signifi cant decrease in MMP-9 activity over time after bleeding (p<0.001). The median MMP-2 activity level was 1.0 in controls, 1.01 in the UB group, 1.50 in the V group, and 1.55 in the VB group. The level of MMP-2 activity was similar in the VB and V groups. Conclusions The level of MMP-9 activity increased in association with VB. The role of MMP-9 in the pathogenesis of VB should be verified. PMID:22570756

  2. Albumin and magnetic resonance imaging-liver volume to identify hepatitis B-related cirrhosis and esophageal varices

    PubMed Central

    Li, Hang; Chen, Tian-Wu; Li, Zhen-Lin; Zhang, Xiao-Ming; Li, Cheng-Jun; Chen, Xiao-Li; Chen, Guang-Wen; Hu, Jia-Ni; Ye, Yong-Quan

    2015-01-01

    AIM: To investigate whether liver lobe volume and albumin (ALB) could predict the presence and severity of liver cirrhosis, and esophageal varices. METHODS: Seventy-one cirrhotic patients with hepatitis B and 21 healthy individuals were enrolled in this study. All the participants underwent abdominal enhanced magnetic resonance imaging to measure each liver lobe volume, and biochemical workup for testing ALB and Child-Pugh class. All cirrhotic patients underwent upper gastrointestinal endoscopy to show the presence of cirrhotic esophageal varices. Right liver lobe volume (RV), left medial liver lobe volume (LMV), left lateral liver lobe volume (LLV), and caudate lobe volume (CV) were measured using enhanced magnetic resonance imaging. The ratios of RV to ALB (RV/ALB), LMV to ALB (LMV/ALB), LLV to ALB (LLV/ALB) and CV to ALB (CV/ALB) were calculated. Statistical analyses were performed to determine whether and how the combination of liver lobe volume measured using magnetic resonance imaging and albumin could predict the presence and severity of liver cirrhosis, and the presence of esophageal varices. RESULTS: RV, LMV, LLV and CV decreased (r = -0.51-0.373; all P < 0.05), while RV/ALB increased (r = 0.424; P < 0.05), with the progress of Child-Pugh class of liver cirrhosis. RV, LMV, CV, LLV/ALB and CV/ALB could identify presence of liver cirrhosis; LLV and LMV could distinguish Child-Pugh class A from B; RV, LMV, LLV, CV, RV/ALB and LLV/ALB could distinguish class A from C; RV and LLV/ALB could differentiate B from C; and RV, RV/ALB and CV/ALB could identify presence of esophageal varices (all P < 0.05). Among these parameters, CV/ALB could best identify the presence of liver cirrhosis, with an area under receiver operating characteristic curve (AUC) of 0.860, a sensitivity of 82.0% and a specificity of 83.0%. LLV could best distinguish class A from B, with an AUC of 0.761, a sensitivity of 74.4% and a specificity of 73.1%. RV could best distinguish class A from C

  3. Modified spleen stiffness measurement by transient elastography is associated with presence of large oesophageal varices in patients with compensated hepatitis C virus cirrhosis.

    PubMed

    Calvaruso, V; Bronte, F; Conte, E; Simone, F; Craxì, A; Di Marco, V

    2013-12-01

    To evaluate the accuracy of liver transient elastography (TE), spleen TE and other noninvasive tests (AAR, APRI score, platelet count, platelet/spleen ratio) in predicting the presence and the size of oesophageal varices in compensated hepatitis C virus (HCV) cirrhosis, we studied 112 consecutive patients with compensated HCV cirrhosis who underwent biochemical tests, gastrointestinal endoscopy, liver TE and spleen TE by Fibroscan(®) (Echosens, Paris, France) using a modified software version with a range between 1.5 and 150 kPa. Spleen TE was not reliable in 16 patients (14.3%). Among the 96 patients with a valid measurement (69.8% men, mean age: 63.2 ± 9.5 years), 43.7% had no oesophageal varices, 29.2% had grade 1% and 27.1% had grade 2 or grade 3 oesophageal varices. Patients with values of 75 kPa by standard spleen TE had mean values of modified spleen TE of 117 kPa (range: 81.7-149.5). Linear regression revealed a significant correlation between modified spleen TE and oesophageal varix size (r = 0.501; beta: 0.763, SE: 0.144; P < 0.001). On univariate analysis, the variables associated with grade 2/grade 3 oesophageal varices were AAR score, APRI score, platelet/spleen ratio, liver TE and modified spleen TE. On multivariate analysis, only modified spleen TE (OR: 1.026; 95% CI: 1.007-1.046; P = 0.006) and AAR (OR: 14.725; 95% CI: 1.928-112.459; P = 0.010) remained independently associated with grade 2/grade 3 oesophageal varices. Platelet/spleen ratio was the best predictor of oesophageal varices area under the ROC curve (AUROC: 0.763, cut-off: 800, sensitivity: 74%, specificity: 70%), while modified spleen TE was more accurate in predicting grade 2/grade 3 oesophageal varices (AUROC: 0.82, cut-off: 54.0 kPa, sensitivity: 80%, specificity: 70%). Portal hypertension increases spleen stiffness, and the measurement of modified spleen TE is an accurate, noninvasive tool for predicting the presence of large oesophageal varices in patients with compensated HCV

  4. In Vitro Selection of Optimal DNA Substrates for Ligation by a Water-Soluble Carbodiimide

    NASA Technical Reports Server (NTRS)

    Harada, Kazuo; Orgel, Leslie E.

    1994-01-01

    We have used in vitro selection to investigate the sequence requirements for efficient template-directed ligation of oligonucleotides at 0 deg C using a water-soluble carbodiimide as condensing agent. We find that only 2 bp at each side of the ligation junction are needed. We also studied chemical ligation of substrate ensembles that we have previously selected as optimal by RNA ligase or by DNA ligase. As anticipated, we find that substrates selected with DNA ligase ligate efficiently with a chemical ligating agent, and vice versa. Substrates selected using RNA ligase are not ligated by the chemical condensing agent and vice versa. The implications of these results for prebiotic chemistry are discussed.

  5. Tuboplasty as a reversal macrosurgery for tubal ligation, is pregnancy possible? A case series

    PubMed Central

    Yassaee, Fakhrolmolouk

    2014-01-01

    Background: Reversal of tubal ligation is requested by some women for various reasons. The present study aims to determine the rate of pregnancy after tubal ligation reversal. Case: In these case series, we reported fifteen women who requested tuboplasty after tubal ligation. In these cases reversal of tubal ligation was done in 15 women. Pregnancy occurred in 4 women (26.6%). Two term pregnancy and 2 abortions were determined. Conclusion: The success rate of pregnancy after macro surgical reversal of tubal ligation is good and can be considered before in vitro fertilization. The type of tubal ligation and the procedure used will determine the best procedure for reversal and have a major impact on chance of success for reversal surgery. PMID:25031582

  6. Menstrual Pattern following Tubal Ligation: A Historical Cohort Study

    PubMed Central

    Sadatmahalleh, Shahideh Jahanian; Ziaei, Saeideh; Kazemnejad, Anoshirvan; Mohamadi, Eesa

    2016-01-01

    Background Tubal ligation (TL) is recommended for women who have completed their family planning. The existence of the menstrual disorders following this procedure has been the subject of debate for decades. This study was conducted to identify the relationship between tubal ligation and menstrual disorders. Materials and Methods A historical cohort study was carried out on 140 women undergoing tubal ligation (TL group) and on 140 women using condom as the main contraceptive method (Non-TL group). They aged between 20 and 40 years and were selected from a health care center in Rudsar, Guilan Province, Iran, during 2013-2014. The two groups were comparable in demographic characteristics, obstetrical features and menstrual bleeding pattern using a routine questionnaire. A validated pictorial blood loss assessment chart (PBLAC) was also used to measure the menstrual blood loss. Results Women with TL had more menstrual irregularity than those without TL (24.3 vs. 10%, P=0.002). Women with TL had more polymenorrhea (9.3 vs. 1.4%, P=0.006), hypermenorrhea (12.1 vs. 2.1%, P=0.002), menorrhagia (62.9 vs. 22.1%, P<0.0001) and menometrorrhagia (15.7 vs. 3.6%, P=0.001) than those without TL. There is a significant difference in the PBLAC score between women with and without TL (P<0.0001). According to logistic regression, age odds ratio [(OR=1.08, con- fidence interval (CI):1.07-1.17, P=0.03)], TL (OR=5.95, CI:3.45-10.26, P<0.0001) and cesarean section (OR=2.72, CI:1.49-4.97, P=0.001) were significantly associated with menorrhagia. Conclusion We found significant differences in menstrual disorders between women with and without TL. Therefore, women should be informed by the health providers regarding the advantages and disadvantages of TL before the procedures. PMID:26985334

  7. Post-functionalization of polymers via orthogonal ligation chemistry.

    PubMed

    Goldmann, Anja S; Glassner, Mathias; Inglis, Andrew J; Barner-Kowollik, Christopher

    2013-05-27

    The establishment of advanced living/controlled polymerization protocols allows for engineering synthetic polymers in a precise fashion. Combining advanced living/controlled polymerization techniques with highly efficient coupling chemistries facilitates quantitative, modular, and orthogonal functionalization of synthetic polymer strands at their chain termini as well as side-chain functionalization. The review highlights the current status of selected post-functionalization techniques of polymers via orthogonal ligation chemistries, major characteristics of the specific transformation chemistry, as well as the characterization of the products.

  8. Non-variceal upper gastrointestinal bleeding: Rescue treatment with a modified cyanoacrylate

    PubMed Central

    Grassia, Roberto; Capone, Pietro; Iiritano, Elena; Vjero, Katerina; Cereatti, Fabrizio; Martinotti, Mario; Rozzi, Gabriele; Buffoli, Federico

    2016-01-01

    AIM To evaluate the safety and efficacy of a modified cyanoacrylate [N-butyl-2-cyanoacrylate associated with methacryloxysulfolane (NBCA + MS)] to treat non-variceal upper gastrointestinal bleeding (NV-UGIB). METHODS In our retrospective study we took into account 579 out of 1177 patients receiving endoscopic treatment for NV-UGIB admitted to our institution from 2008 to 2015; the remaining 598 patients were treated with other treatments. Initial hemostasis was not achieved in 45 of 579 patients; early rebleeding occurred in 12 of 579 patients. Thirty-three patients were treated with modified cyanoacrylate: 27 patients had duodenal, gastric or anastomotic ulcers, 3 had post-mucosectomy bleeding, 2 had Dieulafoy’s lesions, and 1 had duodenal diverticular bleeding. RESULTS Of the 45 patients treated endoscopically without initial hemostasis or with early rebleeding, 33 (76.7%) were treated with modified cyanoacrylate glue, 16 (37.2%) underwent surgery, and 3 (7.0%) were treated with selective transarterial embolization. The mean age of patients treated with NBCA + MS (23 males and 10 females) was 74.5 years. Modified cyanoacrylate was used in 24 patients during the first endoscopy and in 9 patients experiencing rebleeding. Overall, hemostasis was achieved in 26 of 33 patients (78.8%): 19 out of 24 (79.2%) during the first endoscopy and in 7 out of 9 (77.8%) among early rebleeders. Two patients (22.2%) not responding to cyanoacrylate treatment were treated with surgery or transarterial embolization. One patient had early rebleeding after treatment with cyanoacrylate. No late rebleeding during the follow-up or complications related to the glue injection were recorded. CONCLUSION Modified cyanoacrylate solved definitively NV-UGIB after failure of conventional treatment. Some reported life-threatening adverse events with other formulations, advise to use it as last option. PMID:28082813

  9. Prognostic factors associated with mortality in patients with gastric fundal variceal bleeding

    PubMed Central

    Komori, Keishi; Kubokawa, Masaru; Ihara, Eikichi; Akahoshi, Kazuya; Nakamura, Kazuhiko; Motomura, Kenta; Masumoto, Akihide

    2017-01-01

    AIM To determine the prognostic factors associated with mortality in patients with gastric fundal variceal (GFV) bleeding. METHODS In total, 42 patients were endoscopically diagnosed with GFV bleeding from January 2000 to March 2014. We retrospectively reviewed the patients' medical records and assessed their history, etiology of liver cirrhosis, disease conditions, treatment options for GFV bleeding, medications administered before and after onset of GFV bleeding, blood test results (hemoglobin, albumin, and bilirubin concentrations), and imaging results (including computed tomography and abdominal ultrasonography). We also assessed the prognostic factors associated with short-term mortality (up to 90 d) and long-term mortality in all patients. RESULTS Multivariate analysis showed that prophylactic administration of antibiotics was an independent prognostic factor associated with decreases in short-term mortality (OR = 0.08, 95%CI: 0.01-0.52) and long-term mortality (OR = 0.27, 95%CI: 0.08-0.91) in patients with GFV bleeding. In contrast, concurrent hepatocellular carcinoma (HCC) and regular use of proton pump inhibitors (PPI) were independent prognostic factors associated with increases in short-term mortality (HCC: OR = 15.4, 95%CI: 2.08-114.75; PPI: OR = 12.76, 95%CI: 2.13-76.52) and long-term mortality (HCC: OR = 7.89, 95%CI: 1.98-31.58; PPI: OR = 10.91, 95%CI: 2.86-41.65) in patients with GFV bleeding. The long-term overall survival rate was significantly lower in patients who regularly used PPI than in those who did not use PPI (P = 0.0074). CONCLUSION Administration of antibiotics is associated with decreased short- and long-term mortality, while concurrent HCC and regular PPI administration are associated with increased short- and long-term mortality. PMID:28210086

  10. TLR9 ligation in pancreatic stellate cells promotes tumorigenesis

    PubMed Central

    Zambirinis, Constantinos P.; Levie, Elliot; Nguy, Susanna; Avanzi, Antonina; Barilla, Rocky; Xu, Yijie; Seifert, Lena; Daley, Donnele; Greco, Stephanie H.; Deutsch, Michael; Jonnadula, Saikiran; Torres-Hernandez, Alejandro; Tippens, Daniel; Pushalkar, Smruti; Eisenthal, Andrew; Saxena, Deepak; Ahn, Jiyoung; Hajdu, Cristina; Engle, Dannielle D.; Tuveson, David

    2015-01-01

    Modulation of Toll-like receptor (TLR) signaling can have protective or protumorigenic effects on oncogenesis depending on the cancer subtype and on specific inflammatory elements within the tumor milieu. We found that TLR9 is widely expressed early during the course of pancreatic transformation and that TLR9 ligands are ubiquitous within the tumor microenvironment. TLR9 ligation markedly accelerates oncogenesis, whereas TLR9 deletion is protective. We show that TLR9 activation has distinct effects on the epithelial, inflammatory, and fibrogenic cellular subsets in pancreatic carcinoma and plays a central role in cross talk between these compartments. Specifically, TLR9 activation can induce proinflammatory signaling in transformed epithelial cells, but does not elicit oncogene expression or cancer cell proliferation. Conversely, TLR9 ligation induces pancreatic stellate cells (PSCs) to become fibrogenic and secrete chemokines that promote epithelial cell proliferation. TLR9-activated PSCs mediate their protumorigenic effects on the epithelial compartment via CCL11. Additionally, TLR9 has immune-suppressive effects in the tumor microenvironment (TME) via induction of regulatory T cell recruitment and myeloid-derived suppressor cell proliferation. Collectively, our work shows that TLR9 has protumorigenic effects in pancreatic carcinoma which are distinct from its influence in extrapancreatic malignancies and from the mechanistic effects of other TLRs on pancreatic oncogenesis. PMID:26481685

  11. TLR9 ligation in pancreatic stellate cells promotes tumorigenesis.

    PubMed

    Zambirinis, Constantinos P; Levie, Elliot; Nguy, Susanna; Avanzi, Antonina; Barilla, Rocky; Xu, Yijie; Seifert, Lena; Daley, Donnele; Greco, Stephanie H; Deutsch, Michael; Jonnadula, Saikiran; Torres-Hernandez, Alejandro; Tippens, Daniel; Pushalkar, Smruti; Eisenthal, Andrew; Saxena, Deepak; Ahn, Jiyoung; Hajdu, Cristina; Engle, Dannielle D; Tuveson, David; Miller, George

    2015-11-16

    Modulation of Toll-like receptor (TLR) signaling can have protective or protumorigenic effects on oncogenesis depending on the cancer subtype and on specific inflammatory elements within the tumor milieu. We found that TLR9 is widely expressed early during the course of pancreatic transformation and that TLR9 ligands are ubiquitous within the tumor microenvironment. TLR9 ligation markedly accelerates oncogenesis, whereas TLR9 deletion is protective. We show that TLR9 activation has distinct effects on the epithelial, inflammatory, and fibrogenic cellular subsets in pancreatic carcinoma and plays a central role in cross talk between these compartments. Specifically, TLR9 activation can induce proinflammatory signaling in transformed epithelial cells, but does not elicit oncogene expression or cancer cell proliferation. Conversely, TLR9 ligation induces pancreatic stellate cells (PSCs) to become fibrogenic and secrete chemokines that promote epithelial cell proliferation. TLR9-activated PSCs mediate their protumorigenic effects on the epithelial compartment via CCL11. Additionally, TLR9 has immune-suppressive effects in the tumor microenvironment (TME) via induction of regulatory T cell recruitment and myeloid-derived suppressor cell proliferation. Collectively, our work shows that TLR9 has protumorigenic effects in pancreatic carcinoma which are distinct from its influence in extrapancreatic malignancies and from the mechanistic effects of other TLRs on pancreatic oncogenesis.

  12. New insight into the role of NT-proBNP in alcoholic liver cirrhosis as a noninvasive marker of esophageal varices

    PubMed Central

    Ljubičić, Neven; Gomerčić, Marija; Zekanović, Dražen; Bodrožić-, Tomislava; Džakić; Đuzel, Ana

    2012-01-01

    Aim To investigate the association between plasma concentrations of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and formation of esophageal varices. Methods Thirty-five patients with alcoholic cirrhosis were divided into three groups according to the Child-Pugh classification: grade A (n = 11, 32%), B (n = 12, 34%), and C (n = 12, 34%). System hemodynamic parameters were measured using sphygmomanometry, electrocardiography, and echocardiography. NT-proBNP was analyzed by using an electrochemiluminiscence sandwich immunoassay. Results The presence of esophageal varices was associated with a higher serum NT-proBNP level, with a cut-off value of >101 pg/mL (sensitivity, 87.60% and specificity, 72.73%; P < 0.001). Conclusions NT-proBNP was found to be a marker of the presence of esophageal varices, but not a marker of progression of liver cirrhosis. In cirrhotic patients, NT-proBNP value >101 pg/mL was shown to be a valuable noninvasive parameter in predicting the presence of varices. PMID:22911531

  13. Safety and efficacy of 2-octyl-cyanoacrylate in the management of patients with gastric and duodenal varices who are not candidates for transjugular intrahepatic portosystemic shunts

    PubMed Central

    Burdick, James; Trotter, James F.

    2016-01-01

    Gastric variceal bleeding is associated with significant morbidity and mortality in patients with portal hypertension and cirrhosis. Options are limited for patients who are not candidates for transjugular intrahepatic portosystemic shunts (TIPS). Cyanoacrylate injections have been reported to be efficacious in previous case series. The aim of this retrospective study was to report our single-center experience with the safety and efficacy of 2-octyl-cyanoacrylate in patients who were not TIPS candidates. Electronic medical records were reviewed for 16 patients who underwent a total of 18 esophagogastroduodenoscopies for acute gastric or duodenal variceal bleeding and secondary prophylaxis of gastric varices; 14 patients had cirrhosis with an average Model for End-Stage Liver Disease score of 16, and 2 patients had noncirrhotic portal hypertension. Primary endpoints of the study included early and delayed rebleeding rate, complications, and death or liver transplantation. The rebleeding rate (early or delayed) was 7%, and no complications were found. One death was reported (unrelated to the procedure). In conclusion, 2-octyl-cyanoacrylate is a safe and effective alternative for non-TIPS candidates who present with acute gastric variceal bleeding given its low rebleeding and complication rate. PMID:27695164

  14. Application of a standardised protocol for hepatic venous pressure gradient measurement improves quality of readings and facilitates reduction of variceal bleeding in cirrhotics

    PubMed Central

    Tey, Tze Tong; Gogna, Apoorva; Irani, Farah Gillan; Too, Chow Wei; Lo, Hoau Gong Richard; Tan, Bien Soo; Tay, Kiang Hiong; Lui, Hock Foong; Chang, Pik Eu Jason

    2016-01-01

    INTRODUCTION Hepatic venous pressure gradient (HVPG) measurement is recommended for prognostic and therapeutic indications in centres with adequate resources and expertise. Our study aimed to evaluate the quality of HVPG measurements at our centre before and after introduction of a standardised protocol, and the clinical relevance of the HVPG to variceal bleeding in cirrhotics. METHODS HVPG measurements performed at Singapore General Hospital from 2005–2013 were retrospectively reviewed. Criteria for quality HVPG readings were triplicate readings, absence of negative pressure values and variability of ≤ 2 mmHg. The rate of variceal bleeding was compared in cirrhotics who achieved a HVPG response to pharmacotherapy (reduction of the HVPG to < 12 mmHg or by ≥ 20% of baseline) and those who did not. RESULTS 126 HVPG measurements were performed in 105 patients (mean age 54.7 ± 11.4 years; 55.2% men). 80% had liver cirrhosis and 20% had non-cirrhotic portal hypertension (NCPH). The mean overall HVPG was 13.5 ± 7.2 mmHg, with a significant difference between the cirrhosis and NCPH groups (p < 0.001). The proportion of quality readings significantly improved after the protocol was introduced. HVPG response was achieved in 28 (33.3%, n = 84) cirrhotics. Nine had variceal bleeding over a median follow-up of 29 months. The rate of variceal bleeding was significantly lower in HVPG responders compared to nonresponders (p = 0.025). CONCLUSION The quality of HVPG measurements in our centre improved after the introduction of a standardised protocol. A HVPG response can prognosticate the risk of variceal bleeding in cirrhotics. PMID:26996384

  15. Photoinduced axial ligation and deligation dynamics of nonplanar nickel dodecaarylporphyrins.

    PubMed

    Retsek, Jennifer L; Drain, Charles Michael; Kirmaier, Christine; Nurco, Daniel J; Medforth, Craig J; Smith, Kevin M; Sazanovich, Igor V; Chirvony, Vladimir S; Fajer, Jack; Holten, Dewey

    2003-08-13

    The ground- and excited-state metal-ligand dynamics of nonplanar nickel(II) 2,3,5,7,8,10,12,13,15,17,18,20-dodecaphenylporphyrin (NiDPP) and two fluorinated analogues (NiF(20)DPP and NiF(28)DPP) have been investigated using static and time-resolved absorption spectroscopy in toluene and in ligating media that differ in basicity, aromaticity, and steric encumbrance. Because of the electronic and steric consequences of nonplanarity, NiDPP does not bind axial ligands in the ground state, but metal coordination does occur after photoexcitation with multistep dynamics that depend on the properties of the ligand. Following the structural relaxations that occur in all nickel porphyrins within approximately 10 ps, ligand binding to photoexcited NiDPP is progressively longer in pyridine, piperidine, and 3,5-lutidine (25-100 ps) but does not occur at all in 2,6-lutidine in which the ligating nitrogen is sterically encumbered. The transient intermediate that is formed, which nominally could be either a five- or six-coordinate species, also has a ligand-dependent lifetime (200-550 ps). Decay of this intermediate occurs partially via ligand release to re-form the uncoordinated species, in competition with binding of the second axial ligand and/or conformational/electronic relaxations (of a six-coordinate intermediate) to give the ground state of the bis-ligated photoproduct. The finding that the photoproduct channel principally depends on ligand characteristics along with the time-evolving spectra suggests that the transient intermediate may involve a five-coordinate species. In contrast to NiDPP, the fluorinated analogues NiF(20)DPP and NiF(28)DPP do coordinate axial ligands in the ground state but eject them after photoexcitation. Collectively, these results demonstrate the sensitivity with which the electronic and structural characteristics of the macrocycle, substituents, and solvent (ligands) can govern the photophysical and photochemical properties of nonplanar porphyrins

  16. One-pot native chemical ligation by combination of two orthogonal thioester precursors.

    PubMed

    Asahina, Yuya; Kawakami, Toru; Hojo, Hironobu

    2017-02-09

    We developed a one-pot peptide ligation method using two orthogonal thioester precursors and a protecting group for the ligation reaction between Asp and Cys. Combination of the two precursors facilitated the one-pot operation and yielded the entire polypeptide. The usefulness of this method was successfully demonstrated by the total synthesis of histone H4.

  17. Plant Enzymes but Not Agrobacterium VirD2 Mediate T-DNA Ligation In Vitro

    PubMed Central

    Ziemienowicz, Alicja; Tinland, Bruno; Bryant, John; Gloeckler, Veronique; Hohn, Barbara

    2000-01-01

    Agrobacterium tumefaciens, a gram-negative soil bacterium, transfers DNA to many plant species. In the plant cell, the transferred DNA (T-DNA) is integrated into the genome. An in vitro ligation-integration assay has been designed to investigate the mechanism of T-DNA ligation and the factors involved in this process. The VirD2 protein, which is produced in Agrobacterium and is covalently attached to T-DNA, did not, under our assay conditions, ligate T-DNA to a model target sequence in vitro. We tested whether plant extracts could ligate T-DNA to target oligonucleotides in our test system. The in vitro ligation-integration reaction did indeed take place in the presence of plant extracts. This reaction was inhibited by dTTP, indicating involvement of a plant DNA ligase. We found that prokaryotic DNA ligases could substitute for plant extracts in this reaction. Ligation of the VirD2-bound oligonucleotide to the target sequence mediated by T4 DNA ligase was less efficient than ligation of a free oligonucleotide to the target. T-DNA ligation mediated by a plant enzyme(s) or T4 DNA ligase requires ATP. PMID:10938108

  18. Ligation of the hairpin ribozyme in cis induced by freezing and dehydration

    PubMed Central

    KAZAKOV, SERGEI A.; BALATSKAYA, SVETLANA V.; JOHNSTON, BRIAN H.

    2006-01-01

    Although reducing the temperature slows most chemical reactions, freezing can stimulate some reactions by mechanisms that are only partially understood. Here we show that freezing stimulates the self-ligation (circularization) of linear forms of the hairpin ribozyme (HPR) containing 2′,3′-cyclic phosphate and 5′-OH termini. Divalent metal ions (M2+) are not required, but monovalent cations and anions at millimolar concentrations can have various effects on this reaction depending on the specific ion. Under optimal conditions, the observed rate of M2+-independent self-ligation reaches a peak (0.04 min−1) at −10°C with a yield of −60% after 1 h. In contrast, no ligation occurs either at above 0°C or in solutions that remain unfrozen when supercooled to subzero temperatures. Under freezing conditions, the cleavage–ligation equilibrium strongly favors ligation. Besides freezing, evaporation of the aqueous solvent as well as the presence of ethanol at levels of 40% or above can also induce M2+-independent HPR ligation at 25°C. We argue that partial RNA dehydration, which is a common feature of freezing, evaporation, and the presence of ethanol, is a key factor supporting HPR ligation activity at both above- and below-freezing temperatures. In the context of the RNA world hypothesis, freezing-induced ligation is an attractive mechanism by which complex RNAs could have evolved under conditions in which RNA was relatively protected against degradation. PMID:16495237

  19. A facile avenue to conductive polymer brushes via cyclopentadiene-maleimide Diels-Alder ligation.

    PubMed

    Yameen, Basit; Rodriguez-Emmenegger, Cesar; Preuss, Corinna M; Pop-Georgievski, Ognen; Verveniotis, Elisseos; Trouillet, Vanessa; Rezek, Bohuslav; Barner-Kowollik, Christopher

    2013-10-07

    Cyclopentadienyl end-capped poly(3-hexylthiophene) was employed to fabricate conductive surface tethered polymer brushes via a facile route based on cyclopentadiene-maleimide Diels-Alder ligation. The efficient nature of the Diels-Alder ligation was further combined with a biomimetic polydopamine-assisted functionalization of surfaces, making it an access route of choice for P3HT surface immobilization.

  20. [Is a hysterectomy justifiable to prevent post-tubal ligation syndrome?].

    PubMed

    Maheux, R; Fugère, P

    1980-12-01

    Among 2057 tubal ligations performed between 1971-75 in "Hopital Saint-Luc" in Montreal, 78 patients had to be readmitted for hysterectomy. The main indication for hysterectomy among these patients was for menstrual disorders (65%). These menstrual disorders were present at the moment of the tubal ligation in about half of the patients. Among the patients who had to be reoperated for hysterectomy for menstrual disorders and who were asymptomatic at the momemt of their tubal ligation, 88% were using oral contraceptives for a mean period of 5.8 years. The low incidence of hysterectomy post-tubal ligation (3.8%) does not seem to justify a total hysterectomy to prevent what has been described as the "post tubal ligation syndrome" in the patients who are asymptomatic and desire a permanent sterilization. (Author's modified)

  1. Sensitive detection of aggregated prion protein via proximity ligation

    PubMed Central

    Hammond, Maria; Wik, Lotta; Deslys, Jean-Philippe; Comoy, Emmanuel; Linné, Tommy; Landegren, Ulf; Kamali-Moghaddam, Masood

    2014-01-01

    The DNA assisted solid-phase proximity ligation assay (SP-PLA) provides a unique opportunity to specifically detect prion protein (PrP) aggregates by investigating the collocation of 3 or more copies of the specific protein. We have developed an SP-PLA that can detect PrP aggregates in brain homogenates from infected hamsters even after a 107-fold dilution. In contrast, brain homogenate from uninfected animals did not generate a detectable signal at 100-fold higher concentration. Using either of the 2 monoclonal anti-PrP antibodies, 3F4 and 6H4, we successfully detected low concentrations of aggregated PrP. The presented results provide a proof of concept that this method might be an interesting tool in the development of diagnostic approaches of prion diseases. PMID:25482604

  2. Confinement-induced Molecular Templating and Controlled Ligation

    NASA Astrophysics Data System (ADS)

    Berard, Daniel; Shayegan, Marjan; Michaud, François; Henkin, Gil; Scott, Shane; Leith, Jason; Leslie, Sabrina; Leslie Lab Team

    Loading and manipulating long DNA molecules within sub-50 nm cross-section nanostructures for genomic and biochemical analyses, while retaining their structural integrity, present key technological challenges to the biotechnology sector, such as device clogging and molecular breakage. We overcome these challenges by using Convex Lens-induced Confinement (CLiC) technology to gently load DNA into nanogrooves from above. Here, we demonstrate single-fluorophore visualization of custom DNA barcodes as well as efficient top-loading of DNA into sub-50 nm nanogrooves of variable topographies. We study confinement-enhanced self-ligation of polymers loaded in circular nanogrooves. Further, we use concentric, circular nanogrooves to eliminate confinement gradient-induced drift of stretched DNA.

  3. Sensitive detection of aggregated prion protein via proximity ligation.

    PubMed

    Hammond, Maria; Wik, Lotta; Deslys, Jean-Philippe; Comoy, Emmanuel; Linné, Tommy; Landegren, Ulf; Kamali-Moghaddam, Masood

    2014-01-01

    The DNA assisted solid-phase proximity ligation assay (SP-PLA) provides a unique opportunity to specifically detect prion protein (PrP) aggregates by investigating the collocation of 3 or more copies of the specific protein. We have developed an SP-PLA that can detect PrP aggregates in brain homogenates from infected hamsters even after a 10(7)-fold dilution. In contrast, brain homogenate from uninfected animals did not generate a detectable signal at 100-fold higher concentration. Using either of the 2 monoclonal anti-PrP antibodies, 3F4 and 6H4, we successfully detected low concentrations of aggregated PrP. The presented results provide a proof of concept that this method might be an interesting tool in the development of diagnostic approaches of prion diseases.

  4. Detection of Protein SUMOylation In Situ by Proximity Ligation Assays.

    PubMed

    Sahin, Umut; Jollivet, Florence; Berthier, Caroline; de Thé, Hugues; Lallemand-Breitenbach, Valérie

    2016-01-01

    Sumoylation is a posttranslational process essential for life and concerns a growing number of crucial proteins. Understanding the influence of this phenomenon on individual proteins or on cellular pathways in which they function has become an intense area of research. A critical step in studying protein sumoylation is to detect sumoylated forms of a particular protein. This has proven to be a challenging task for a number of reasons, especially in the case of endogenous proteins and in vivo studies or when studying rare cells such as stem cells. Proximity ligation assays that allow detection of closely interacting protein partners can be adapted for initial detection of endogenous sumoylation or ubiquitination in a rapid, ultrasensitive, and cheap manner. In addition, modified forms of a given protein can be detected in situ in various cellular compartments. Finally, the flexibility of this technique may allow rapid screening of drugs and stress signals that may modulate protein sumoylation.

  5. Left Atrial Appendage Ligation and Exclusion Technology in the Incubator

    PubMed Central

    Syed, Faisal F.; Noheria, Amit; DeSimone, Christopher V.; Asirvatham, Samuel J.

    2016-01-01

    Stroke is the most feared complication of atrial fibrillation (AF). Targeting the left atrial appendage (LAA) mechanically is attractive as a means to simultaneously reduce stroke risk, the need for anticoagulation, and hemorrhagic complications in patients with non-valvular AF. The results of the PROTECT-AF and PREVAIL randomized clinical trials support this approach as a viable therapeutic alternative to warfarin in selected patients and add to accumulating evidence regarding the importance of the LAA in thromboembolism in AF. A number of devices for percutaneous LAA closure are under investigation or development. In this article, key design features of these ligation and exclusion technologies will be discussed, with a focus on aspects of LAA morphology, relational anatomy, thrombosis, and thromboembolism relevant for successful device development and deployment. PMID:27087888

  6. Bioorthogonal Oxime Ligation Mediated In Vivo Cancer Targeting.

    PubMed

    Tang, Li; Yin, Qian; Xu, Yunxiang; Zhou, Qin; Cai, Kaimin; Yen, Jonathan; Dobrucki, Lawrence W; Cheng, Jianjun

    2015-04-01

    Current cancer targeting relying on specific biological interaction between cell surface antigen and respective antibody or its analogue has proven to be effective in the treatment of different cancers; however, this strategy has its own limitations, such as heterogeneity of cancer cells and immunogenicity of the biomacromolecule binding ligands. Bioorthogonal chemical conjugation has emerged as an attractive alternative to biological interaction for in vivo cancer targeting. Here, we report an in vivo cancer targeting strategy mediated by bioorthogonal oxime ligation. Oxyamine group, the artificial target, is introduced onto 4T1 murine breast cancer cells through liposome delivery and fusion. Poly(ethylene glycol) -polylactide (PEG-PLA) nanoparticle (NP) is surface-functionalized with aldehyde groups as targeting ligands. The improved in vivo cancer targeting of PEG-PLA NPs is achieved through specific and efficient chemical reaction between the oxyamine and aldehyde groups.

  7. In Situ Vesicle Formation by Native Chemical Ligation

    PubMed Central

    Brea, Roberto J.; Cole, Christian M.

    2015-01-01

    Phospholipid vesicles are of intense fundamental and practical interest, yet methods for their de novo generation from reactive precursors are limited. A non-enzymatic and chemoselective method to spontaneously generate phospholipid membranes from water-soluble starting materials would be a powerful tool for generating vesicles and studying lipid membranes. Here we describe the use of native chemical ligation (NCL) to rapidly prepare phospholipids spontaneously from thioesters. While NCL is one of the most popular tools for synthesizing proteins and nucleic acids, to our knowledge this is the first example of using NCL to generate phospholipids de novo. The lipids are capable of in situ synthesis and self-assembly into vesicles that can grow to several microns in diameter. The selectivity of the NCL reaction enables compatibility of in situ membrane formation with biological materials such as proteins. This work expands the application of NCL to the formation of phospholipid membranes. PMID:25346090

  8. Bioorthogonal Oxime Ligation Mediated In Vivo Cancer Targeting

    PubMed Central

    Tang, Li; Yin, Qian; Xu, Yunxiang; Zhou, Qin; Cai, Kaimin; Yen, Jonathan; Dobrucki, Lawrence W.

    2015-01-01

    Current cancer targeting relying on specific biological interaction between cell surface antigen and respective antibody or its analogue has proven to be effective in the treatment of different cancers; however, this strategy has its own limitations, such as heterogeneity of cancer cells and immunogenicity of the biomacromolecule binding ligands. Bioorthogonal chemical conjugation has emerged as an attractive alternative to biological interaction for in vivo cancer targeting. Here, we report an in vivo cancer targeting strategy mediated by bioorthogonal oxime ligation. Oxyamine group, the artificial target, is introduced onto 4T1 murine breast cancer cells through liposome delivery and fusion. Poly(ethylene glycol) -polylactide (PEG-PLA) nanoparticle (NP) is surface-functionalized with aldehyde groups as targeting ligands. The improved in vivo cancer targeting of PEG-PLA NPs is achieved through specific and efficient chemical reaction between the oxyamine and aldehyde groups. PMID:26146536

  9. In vivo multiphoton imaging of bile duct ligation

    NASA Astrophysics Data System (ADS)

    Liu, Yuan; Li, Feng-Chieh; Chen, Hsiao-Chin; Chang, Po-shou; Yang, Shu-Mei; Lee, Hsuan-Shu; Dong, Chen-Yuan

    2008-02-01

    Bile is the exocrine secretion of liver and synthesized by hepatocytes. It is drained into duodenum for the function of digestion or drained into gallbladder for of storage. Bile duct obstruction is a blockage in the tubes that carry bile to the gallbladder and small intestine. However, Bile duct ligation results in the changes of bile acids in serum, liver, urine, and feces1, 2. In this work, we demonstrate a novel technique to image this pathological condition by using a newly developed in vivo imaging system, which includes multiphoton microscopy and intravital hepatic imaging chamber. The images we acquired demonstrate the uptake, processing of 6-CFDA in hepatocytes and excretion of CF in the bile canaliculi. In addition to imaging, we can also measure kinetics of the green fluorescence intensity.

  10. Seamless Ligation Cloning Extract (SLiCE) cloning method.

    PubMed

    Zhang, Yongwei; Werling, Uwe; Edelmann, Winfried

    2014-01-01

    SLiCE (Seamless Ligation Cloning Extract) is a novel cloning method that utilizes easy to generate bacterial cell extracts to assemble multiple DNA fragments into recombinant DNA molecules in a single in vitro recombination reaction. SLiCE overcomes the sequence limitations of traditional cloning methods, facilitates seamless cloning by recombining short end homologies (15-52 bp) with or without flanking heterologous sequences and provides an effective strategy for directional subcloning of DNA fragments from bacterial artificial chromosomes or other sources. SLiCE is highly cost-effective and demonstrates the versatility as a number of standard laboratory bacterial strains can serve as sources for SLiCE extract. We established a DH10B-derived E. coli strain expressing an optimized λ prophage Red recombination system, termed PPY, which facilitates SLiCE with very high efficiencies.

  11. Variceal hemorrhage: Saudi tertiary center experience of clinical presentations, complications and mortality

    PubMed Central

    Fallatah, Hind I; Al Nahdi, Haifaa; Al Khatabi, Maan; Akbar, Hisham O; Qari, Yousif A; Sibiani, Abdul Rahman; Bazaraa, Salim

    2012-01-01

    AIM: To determine the clinical presentation, underlying etiology and short- and long-term outcomes of acute variceal bleeding (AVB). METHODS: A retrospective descriptive cohort study of cirrhotic patients with AVB who were admitted to King Abdul Aziz University Hospital between January 2005 and December 2009. We obtained demographic data for all patients. For each patient we also obtained the clinical data at presentation; cause of liver cirrhosis, bleeding presentation (hematemesis and/or melena), presence of ascites, hepatic encephalopathy and renal impairment (RI) or hepatorenal syndrome. We carried out complete blood count, prothrombin time evaluation, and liver function tests. We also report all episodes of re-bleeding after the first episode of AVB, both during the initial admission and after discharge. We recorded the length of stay for each patient and thereby calculated the mean duration of stay for all patients. The length of follow-up after the first AVB and the outcome for each patient at the end of the study period were recorded. Causes of mortality either related to liver disease or non-liver disease cause were determined. RESULTS: A 125 patients were enrolled in the study. The number of episodes of AVB for each patients varied between 1 and 10. Survival from the first attack of AVB to death was 20.38 mo (SD 30.86), while the length of follow-up for the living patients was 53.58 mo (SD 24.94). Total number of AVB admissions was 241. Chronic hepatitis C, the commonest underlying etiology for liver disease, was present in 46 (36.8%) patients. Only 35 (28%) patients had received a primary prophylactic β-blocker before the first bleeding episode. The mean hemoglobin level at the time of admission was 8.59 g/dL (SD 2.53). Most patients had Child-Pugh Class C 41 (32.8%) or Class B 72 (57.6%) disease. Hematemesis was the predominant symptom and was found in 119 (95.2%) patients, followed by melena in 75 (60.0%) patients. Ascites of variable extent was

  12. Coarctation of the Aorta as a Complication of Surgical Ligation of Patent Ductus Arteriosus in a Premature Infant

    PubMed Central

    Qasim, Amna; Jain, Sunil K.; Jiwani, Amyn K.

    2017-01-01

    Surgical ligation of a patent ductus arteriosus (PDA) is a commonly performed procedure. Complications are infrequent and most commonly include recurrent laryngeal nerve injury and rarely ligation of left pulmonary artery. We report a case of accidental ligation of the descending thoracic aorta leading to a clinically significant coarctation. PMID:28386503

  13. Kinetic and mechanistic analysis of nonenzymatic, template-directed oligoribonucleotide ligation

    NASA Technical Reports Server (NTRS)

    Rohatgi, R.; Bartel, D. P.; Szostak, J. W.

    1996-01-01

    The role of divalent cations in the mechanism of pyrophosphate-activated, template-directed oligoribonucleotide ligation has been investigated. The dependence of the reaction rate on Mg2+ concentration suggests a kinetic scheme in which a Mg2+ ion must bind before ligation can proceed. Mn2+, Ca2+, Sr2+, and Ba2+ can also catalyze the reaction. Although Pb2+ and Zn2+ do not catalyze the reaction in the absence of other divalent ions, they significantly modulate the reaction rate when added in the presence of Mg2+, with Pb2+ stimulating the reaction (up to 65-fold) and Zn2+ inhibiting the reaction. The logarithm of the ligation rate increases linearly, with slope of 0.95, as a function of pH, indicating that the reaction involves a single critical deprotonation step. The ligation rates observed with the different divalent metal ion catalysts (Mn2+ > Mg2+ > Ca2+ > Sr2+ = Ba2+) vary inversely with the pKa values of their bound water molecules. The pH profile and these relative ligation rates suggest a mechanism in which a metal-bound hydroxide ion located near the ligation junction promotes catalysis, most likely by deprotonation of the hydroxl nucleophile. The effects of changing either the leaving group or the attacking hydroxyl, together with the large delta S(++) value for oligonucleotide ligation (about -20 eu), are consistent with an associative transition state.

  14. Efficient DNA ligation in DNA-RNA hybrid helices by Chlorella virus DNA ligase.

    PubMed

    Lohman, Gregory J S; Zhang, Yinhua; Zhelkovsky, Alexander M; Cantor, Eric J; Evans, Thomas C

    2014-02-01

    Single-stranded DNA molecules (ssDNA) annealed to an RNA splint are notoriously poor substrates for DNA ligases. Herein we report the unexpectedly efficient ligation of RNA-splinted DNA by Chlorella virus DNA ligase (PBCV-1 DNA ligase). PBCV-1 DNA ligase ligated ssDNA splinted by RNA with kcat ≈ 8 x 10(-3) s(-1) and K(M) < 1 nM at 25 °C under conditions where T4 DNA ligase produced only 5'-adenylylated DNA with a 20-fold lower kcat and a K(M) ≈ 300 nM. The rate of ligation increased with addition of Mn(2+), but was strongly inhibited by concentrations of NaCl >100 mM. Abortive adenylylation was suppressed at low ATP concentrations (<100 µM) and pH >8, leading to increased product yields. The ligation reaction was rapid for a broad range of substrate sequences, but was relatively slower for substrates with a 5'-phosphorylated dC or dG residue on the 3' side of the ligation junction. Nevertheless, PBCV-1 DNA ligase ligated all sequences tested with 10-fold less enzyme and 15-fold shorter incubation times than required when using T4 DNA ligase. Furthermore, this ligase was used in a ligation-based detection assay system to show increased sensitivity over T4 DNA ligase in the specific detection of a target mRNA.

  15. Recursive directional ligation by plasmid reconstruction allows rapid and seamless cloning of oligomeric genes.

    PubMed

    McDaniel, Jonathan R; Mackay, J Andrew; Quiroz, Felipe García; Chilkoti, Ashutosh

    2010-04-12

    This paper reports a new strategy, recursive directional ligation by plasmid reconstruction (PRe-RDL), to rapidly clone highly repetitive polypeptides of any sequence and specified length over a large range of molecular weights. In a single cycle of PRe-RDL, two halves of a parent plasmid, each containing a copy of an oligomer, are ligated together, thereby dimerizing the oligomer and reconstituting a functional plasmid. This process is carried out recursively to assemble an oligomeric gene with the desired number of repeats. PRe-RDL has several unique features that stem from the use of type IIs restriction endonucleases: first, PRe-RDL is a seamless cloning method that leaves no extraneous nucleotides at the ligation junction. Because it uses type IIs endonucleases to ligate the two halves of the plasmid, PRe-RDL also addresses the major limitation of RDL in that it abolishes any restriction on the gene sequence that can be oligomerized. The reconstitution of a functional plasmid only upon successful ligation in PRe-RDL also addresses two other limitations of RDL: the significant background from self-ligation of the vector observed in RDL, and the decreased efficiency of ligation due to nonproductive circularization of the insert. PRe-RDL can also be used to assemble genes that encode different sequences in a predetermined order to encode block copolymers or append leader and trailer peptide sequences to the oligomerized gene.

  16. Transjugular intrahepatic portosystemic shunt combined with esophagogastric variceal embolization in the treatment of a large gastrorenal shunt

    PubMed Central

    Jiang, Qin; Wang, Ming-Quan; Zhang, Guo-Bing; Wu, Qiong; Xu, Jian-Ming; Kong, De-Run

    2016-01-01

    AIM: To evaluate the efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) combined with stomach and esophageal variceal embolization (SEVE) in cirrhotic patients with a large gastrorenal vessel shunt (GRVS). METHODS: Eighty-one cirrhotic patients with gastric variceal bleeding (GVB) associated with a GRVS were enrolled in the study and accepted TIPS combined with SEVE (TIPS + SEVE), by which portosystemic pressure gradient (PPG), biochemical, TIPS-related complications, shunt dysfunction, rebleeding, and death were evaluated. RESULTS: The PPGs before TIPS were greater than 12 mmHg in 81 patients. TIPS + SEVE treatment caused a significant decrease in PPG (from 37.97 ± 6.36 mmHg to 28.15 ± 6.52 mmHg, t = 19.22, P < 0.001). The percentage of reduction in PPG was greater than 20% from baseline. There were no significant differences in albumin, alanine aminotransferase, aspartate aminotransferase, bilirubin, prothrombin time, or Child-Pugh score before and after operation. In all patients, rebleeding rates were 3%, 6%, 12%, 18%, and 18% at 1, 3, 6, 12, and 18 mo, respectively. Five patients (6.2%) were diagnosed as having hepatic encephalopathy. The rates of shunt dysfunction were 0%, 4%, 9%, 26%, and 26%, at 1, 3, 6, 12, and 18 mo, respectively. The cumulative survival rates in 1, 3, 6, 12, and 18 mo were 100%, 100%, 95%, 90%, and 90%, respectively. CONCLUSION: Our preliminary results indicated that the efficacy and safety of TIPS + SEVE were satisfactory in cirrhotic patients with GVB associated with a GRVS (GVB + GRVS). PMID:27458505

  17. Isolation and characterization of portal branch ligation-stimulated Hmga2-positive bipotent hepatic progenitor cells

    SciTech Connect

    Sakai, Hiroshi; Tagawa, Yoh-ichi; Tamai, Miho; Motoyama, Hiroaki; Ogawa, Shinichiro; Soeda, Junpei; Nakata, Takenari; Miyagawa, Shinichi

    2010-12-17

    Research highlights: {yields} Hepatic progenitor cells were isolated from the portal branch-ligated liver of mice. {yields} Portal branch ligation-stimulated hepatic progenitor cells (PBLHCs) express Hmga2. {yields} PBLHCs have bidirectional differentiation capability in vitro. -- Abstract: Hepatic stem/progenitor cells are one of several cell sources that show promise for restoration of liver mass and function. Although hepatic progenitor cells (HPCs), including oval cells, are induced by administration of certain hepatotoxins in experimental animals, such a strategy would be inappropriate in a clinical setting. Here, we investigated the possibility of isolating HPCs in a portal branch-ligated liver model without administration of any chemical agents. A non-parenchymal cell fraction was prepared from the portal branch-ligated or non-ligated lobe, and seeded onto plates coated with laminin. Most of the cells died, but a small number were able to proliferate. These proliferating cells were cloned as portal branch ligation-stimulated hepatic cells (PBLHCs) by the limiting dilution method. The PBLHCs expressed cytokeratin19, albumin, and Hmga2. The PBLHCs exhibited metabolic functions such as detoxification of ammonium ions and synthesis of urea on Matrigel-coated plates in the presence of oncostatin M. In Matrigel mixed with type I collagen, the PBLHCs became rearranged into cystic and tubular structures. Immunohistochemical staining demonstrated the presence of Hmga2-positive cells around the interlobular bile ducts in the portal branch-ligated liver lobes. In conclusion, successful isolation of bipotent hepatic progenitor cell clones, PBLHCs, from the portal branch-ligated liver lobes of mice provides the possibility of future clinical application of portal vein ligation to induce hepatic progenitor cells.

  18. Evaluation of small ligand-protein interaction by ligation reaction with DNA-modified ligand.

    PubMed

    Sugita, Rie; Mie, Masayasu; Funabashi, Hisakage; Kobatake, Eiry

    2010-01-01

    A method for the evaluation of interactions between protein and ligand using DNA-modified ligands, including signal enhancement of the DNA ligation reactions, is described. For proof of principle, a DNA probe modified by biotin was used. Two DNA probes were prepared with complementary sticky-ends. While one DNA probe was modified at the 5'-end of the sticky-end, the other was not modified. The probes could be ligated together by T4 DNA ligase along the strand without biotin modification. However, in the presence of streptavidin or anti-biotin Fab, the ligation reaction joining the two probes could not occur on either strand.

  19. A modified version of the digestion-ligation cloning method for more efficient molecular cloning.

    PubMed

    Gao, Song; Li, Yanling; Zhang, Jiannan; Chen, Hongman; Ren, Daming; Zhang, Lijun; An, Yingfeng

    2014-05-15

    Here we describe a modified version of the digestion-ligation approach for efficient molecular cloning. In comparison with the original method, the modified method has the additional steps of gel purification and a second ligation after the first ligation of the linearized vector and DNA insert. During this process, the efficiency and reproducibility could be significantly improved for both stick-end cloning and blunt-end cloning. As an improvement of the very important molecular cloning technique, this method may find a wide range of applications in bioscience and biotechnology.

  20. A Novel Model of Severe Gallstone Pancreatitis: Murine Pancreatic Duct Ligation Results in Systemic Inflammation and Substantial Mortality

    PubMed Central

    Samuel, Isaac; Yuan, Zuobiao; Meyerholz, David K.; Twait, Erik; Williard, Deborah E.; Kempuraj, Duraisamy

    2010-01-01

    Background Suitable experimental models of gallstone pancreatitis with systemic inflammation and mortality are limited. We developed a novel murine model of duct-ligation-induced acute pancreatitis associated with multiorgan dysfunction and severe mortality. Methods Laparotomy was done on C57/BL6 mice followed by pancreatic duct (PD) ligation, bile duct (BD) ligation without PD ligation, or sham operation. Results Only mice with PD ligation developed acute pancreatitis and had 100% mortality. Pulmonary compliance was significantly reduced after PD ligation but not BD ligation. Bronchoalveolar lavage fluid neutrophil count and interleukin-1β concentration, and the plasma creatinine level, were significantly elevated with PD ligation but not BD ligation. Pancreatic nuclear factor κB (p65) and activator protein 1 (c-Jun) were activated within 1 h of PD ligation. Conclusion PD-ligation-induced acute pancreatitis in mice is associated with systemic inflammation, acute lung injury, multiorgan dysfunction and death. The development of this novel model is an exciting and notable advance in the field. PMID:20975317

  1. Effect of Ligation Method on Maxillary Arch Force/Moment Systems for a Simulated Lingual Incisor Malalignment

    PubMed Central

    Seru, Surbhi; Romanyk, Dan L; Toogood, Roger W; Carey, Jason P; Major, Paul W

    2014-01-01

    Introduction: The objectives of this study were to determine whether there is a difference in the magnitude of forces and moments produced by elastic ligation when compared to passive ligation, and whether these forces and moments propagate differently along the arch for the two ligation types. A lingual incisor malalignment was used in this study. Methods: The Orthodontic Simulator (OSIM) was used to quantify the three-dimensional forces and moments applied on the teeth given a lingually displaced incisor. A repeated measures MANOVA was performed to statistically analyze the data. Results: The interaction factor illustrated convincing evidence that there is a difference in maximum force and moment values for all outcome variables between ligation types considering all tooth positions along the arch. The mean differences for FX and FY between ligation types were found to be clinically significant, with values for elastic ligation consistently higher than passive ligation. Conclusion: It was found that the maximum forces and moments produced by elastic ligation are greater than those produced by passive ligation and that the magnitude of this difference for the mesiodistal and buccolingual forces is clinically relevant. Additionally, it was determined that elastic ligation causes forces and moments to propagate further along the arch than passive ligation for all outcome variables. PMID:25400715

  2. Expanded utility of the native chemical ligation reaction.

    PubMed

    Yeo, Dawn S Y; Srinivasan, Rajavel; Chen, Grace Y J; Yao, Shao Q

    2004-10-04

    The post-genomic era heralds a multitude of challenges for chemists and biologists alike, with the study of protein functions at the heart of much research. The elucidation of protein structure, localization, stability, post-translational modifications, and protein interactions will steadily unveil the role of each protein and its associated biological function in the cell. The push to develop new technologies has necessitated the integration of various disciplines in science. Consequently, the role of chemistry has never been so profound in the study of biological processes. By combining the strengths of recombinant DNA technology, protein splicing, organic chemistry, and the chemoselective chemistry of native chemical ligation, various strategies have been successfully developed and applied to chemoselectively label proteins, both in vitro and in live cells, with biotin, fluorescent, and other small molecule probes. The site-specific incorporation of molecular entities with unique chemical functionalities in proteins has many potential applications in chemical and biological studies of proteins. In this article, we highlight recent progress of these strategies in several areas related to proteomics and chemical biology, namely, in vitro and in vivo protein biotinylation, protein microarray technologies for large-scale protein analysis, and live-cell bioimaging.

  3. Laparoscopic ligation of varicoceles: an anatomically superior operation.

    PubMed Central

    al-Shareef, Z. H.; Koneru, S. R.; al-Tayeb, A.; Shehata, Z. M.; Aly, T. F.; Basyouni, A.

    1993-01-01

    Since December 1991, 25 consecutive symptomatic male patients with 26 varicoceles were treated by laparoscopic ligation of internal spermatic veins under general anaesthesia. Twenty-one patients had either scrotal discomfort or painful swelling and four patients presented with infertility. The mean follow-up period is 5 months (range 3 weeks to 9 months). The procedure has provided a satisfactory outcome in 19 out of 21 patients (90.5%) with scrotal symptoms. Of the four patients presenting with infertility due to oligospermia, three had significantly elevated sperm counts at 3 months which resulted in one pregnancy. So far there has been no recurrence of the varicocele. The main potential advantage of the laparoscopic approach is better visualisation of the anatomy, especially the testicular artery and the collateral venous circulation at the level of the internal inguinal ring. In addition to being less invasive with implied benefits, the endoscopic procedure has enabled identification of multiple veins in 22 out of 26 (84.6%) varicoceles in our series. PMID:8166797

  4. Endoscopic band ligation for bleeding lesions in the small bowel

    PubMed Central

    Ikeya, Takashi; Ishii, Naoki; Shimamura, Yuto; Nakano, Kaoru; Ego, Mai; Nakamura, Kenji; Takagi, Koichi; Fukuda, Katsuyuki; Fujita, Yoshiyuki

    2014-01-01

    AIM: To investigate the safety and efficacy of endoscopic band ligation (EBL) for bleeding lesions in the small bowel. METHODS: This is a retrospective study evaluating EBL in six consecutive patients (three males, three females, 46-86 years of age) treated between May 2009 and February 2014: duodenal vascular ectasia; 1, jejunal bleeding diverticulum; 1, ileal Dieulafoy’s lesion; 1 and ileal bleeding diverticula; 3. The success of the initial hemostasis was evaluated, and patients were observed for early rebleeding (within 30 d after EBL), and complications such as perforation and abscess formation. Follow-up endoscopies were performed in four patients. RESULTS: Initial hemostasis was successfully achieved with EBL in all six patients. Eversion was not sufficient in four diverticular lesions. Early rebleeding occurred three days after EBL in one ileal diverticulum, and a repeat endoscopy revealed dislodgement of the O-band and ulcer formation at the banded site. This rebleeding was managed conservatively. Late rebleeding occurred in this case (13 and 21 mo after initial EBL), and re-EBL was performed. Follow-up endoscopies revealed scar formation and the disappearance of vascular lesions at the banded site in the case with a duodenal bleeding lesion, and unresolved ileal diverticula in three cases. Surgery or transarterial embolization was not required without any complications during the median follow-up period of 45 (range, 2-83) mo. CONCLUSION: EBL is a safe and effective endoscopic treatment for hemostasis of bleeding lesions in the small bowel. PMID:25324920

  5. Melatonin Alleviates Liver Apoptosis in Bile Duct Ligation Young Rats

    PubMed Central

    Sheen, Jiunn-Ming; Chen, Yu-Chieh; Hsu, Mei-Hsin; Tain, You-Lin; Huang, Ying-Hsien; Tiao, Mao-Meng; Li, Shih-Wen; Huang, Li-Tung

    2016-01-01

    Bile duct ligation (BDL)-treated rats display cholestasis and liver damages. The potential protective activity of melatonin in young BDL rats in terms of apoptosis, mitochondrial function, and endoplasmic reticulum (ER) homeostasis has not yet been evaluated. Three groups of young male Sprague-Dawley rats were used: one group received laparotomy (Sham), a second group received BDL for two weeks (BDL), and a third group received BDL and intraperitoneal melatonin (100 mg/day) for two weeks (BDL + M). BDL group rats showed liver apoptosis, increased pro-inflamamtory mediators, caspases alterations, anti-apoptotic factors changes, and dysfunction of ER homeostasis. Melatonin effectively reversed apoptosis, mainly through intrinsic pathway and reversed ER stress. In addition, in vitro study showed melatonin exerted its effect mainly through the melatonin 2 receptor (MT2) in HepG2 cells. In conclusion, BDL in young rats caused liver apoptosis. Melatonin rescued the apoptotic changes via the intrinsic pathway, and possibly through the MT2 receptor. Melatonin also reversed ER stress induced by BDL. PMID:27556445

  6. Could there be light at the end of the tunnel? Mesocaval shunting for refractory esophageal varices in patients with contraindications to transjugular intrahepatic portosystemic shunt

    PubMed Central

    Davis, Jessica; Chun, Albert K; Borum, Marie L

    2016-01-01

    Cirrhotic patients with recurrent variceal bleeds who have failed prior medical and endoscopic therapies and are not transjugular intrahepatic portosystemic shunt candidates face a grim prognosis with limited options. We propose that mesocaval shunting be offered to this group of patients as it has the potential to decrease portal pressures and thus decrease the risk of recurrent variceal bleeding. Mesocaval shunts are stent grafts placed by interventional radiologists between the mesenteric system, most often the superior mesenteric vein, and the inferior vena cava. This allows flow to bypass the congested hepatic system, reducing portal pressures. This technique avoids the general anesthesia and morbidity associated with surgical shunt placement and has been successful in several case reports. In this paper we review the technique, candidate selection, potential pitfalls and benefits of mesocaval shunt placement. PMID:27429715

  7. Comparison of Transjugular Intrahepatic Portosystemic Shunt with Covered Stent and Balloon-Occluded Retrograde Transvenous Obliteration in Managing Isolated Gastric Varices

    PubMed Central

    Lee, Kristen A.; Sauk, Steven; Korenblat, Kevin

    2017-01-01

    Objective Although a transjugular intrahepatic portosystemic shunt (TIPS) is commonly placed to manage isolated gastric varices, balloon-occluded retrograde transvenous obliteration (BRTO) has also been used. We compare the long-term outcomes from these procedures based on our institutional experience. Materials and Methods We conducted a retrospective review of patients with isolated gastric varices who underwent either TIPS with a covered stent or BRTO between January 2000 and July 2013. We identified 52 consecutive patients, 27 who had received TIPS with a covered stent and 25 who had received BRTO. We compared procedural complications, re-bleeding rates, and clinical outcomes between the two groups. Results There were no significant differences in procedural complications between patients who underwent TIPS (7%) and those who underwent BRTO (12%) (p = 0.57). There were also no statistically significant differences in re-bleeding rates from gastric varices between the two groups (TIPS, 7% [2/27]; BRTO, 8% [2/25]; p = 0.94) or in developing new ascites following either procedure (TIPS, 4%; BRTO, 4%; p = 0.96); significantly more patients who underwent TIPS developed hepatic encephalopathy (22%) than did those who underwent BRTO (0%, p = 0.01). There was no statistically significant difference in mean survival between the two groups (TIPS, 30 months; BRTO, 24 months; p = 0.16); median survival for the patients who received TIPS was 16.6 months, and for those who underwent BRTO, it was 26.6 months. Conclusion BRTO is an effective method of treating isolated gastric varices with similar outcomes and complication rates to those of TIPS with a covered stent but with a lower rate of hepatic encephalopathy. PMID:28246514

  8. Somatostatin plus isosorbide 5-mononitrate versus somatostatin in the control of acute gastro-oesophageal variceal bleeding: a double blind, randomised, placebo controlled clinical trial

    PubMed Central

    Junquera, F; Lopez-Talavera, J; Mearin, F; Saperas, E; Videla, S; Armengol, J; Esteban, R; Malagelada, J

    2000-01-01

    BACKGROUND—Variceal bleeding is a severe complication of portal hypertension. Somatostatin reduces portal pressure by decreasing splanchnic blood flow, and nitrates by diminishing intrahepatic resistance. Experimental studies have shown that the combination of somatostatin and nitrates has an additive effect in decreasing portal pressure.
AIM—To compare the therapeutic efficacy of either intravenous infusion of somatostatin plus oral isosorbide 5-mononitrate or somatostatin alone in gastro-oesophageal variceal bleeding associated with liver cirrhosis.
METHODS—A unicentre, double blind, placebo controlled, clinical trial was conducted. Sixty patients bleeding from oesophageal or gastric varices were randomised to receive intravenous infusion of somatostatin (250 µg/hour) plus oral isosorbide 5-mononitrate (40 mg/12 hours) (group I) or somatostatin infusion plus placebo (group II) for 72 hours.
RESULTS—The two groups of patients had similar clinical, endoscopic, and haematological characteristics. Control of bleeding was achieved in 18 out of 30 patients (60%) in group I and 26 out of 30 patients (87%) in group II (p<0.05). There was no significant difference in mean transfusion requirements between the two groups: 2.6 (2.2) v 1.8 (1.6) respectively; means (SD). Mortality and side effects were similar in the two groups, but development of ascites was higher in group I (30%) than in group II (7%) (p<0.05).
CONCLUSION—In cirrhotic patients with acute gastro-oesophageal variceal bleeding, addition of isosorbide 5-mononitrate to somatostatin does not improve therapeutic efficacy, induces more adverse effects, and should not be used.


Keywords: gastro-oesophageal bleeding; haemorrhage; portal hypertension; clinical trial; isosorbide 5-mononitrate; somatostatin PMID:10601068

  9. Chemical ligation methods for the tagging of DNA-encoded chemical libraries.

    PubMed

    Keefe, Anthony D; Clark, Matthew A; Hupp, Christopher D; Litovchick, Alexander; Zhang, Ying

    2015-06-01

    The generation of DNA-encoded chemical libraries requires the unimolecular association of multiple encoding oligonucleotides with encoded chemical entities during combinatorial synthesis processes. This has traditionally been achieved using enzymatic ligation. We discuss a range of chemical ligation methods that provide alternatives to enzymatic ligation. These chemical ligation methods include the generation of modified internucleotide linkages that support polymerase translocation and other modified linkages that while not supporting the translocation of polymerases can also be used to generate individual cDNA molecules containing encoded chemical information specifying individual library members. We also describe which of these approaches have been successfully utilized for the preparation of DNA-encoded chemical libraries and those that were subsequently used for the discovery of inhibitors.

  10. Nonenzymatic ligation of an RNA oligonucleotide analyzed by atomic force microscopy.

    PubMed

    Pino, Samanta; Biasiucci, Mariano; Scardamaglia, Mattia; Gigli, Giuseppe; Betti, Maria Grazia; Mariani, Carlo; Di Mauro, Ernesto

    2011-05-19

    The products of ligation reaction of a 24 nucleotides long PolyA RNA adsorbed on mica were observed by atomic force microscopy. The occurrence of oligonucleotides at different degrees of polymerization has been quantitatively studied before and after ligation reaction. The microscopy images at the nanoscale show that nonenzymatic ligation of pristine RNA monomers results in the formation of supramolecular aggregates, with prevalence of dimers and tetramers. Analytical conditions were defined allowing the identification, the quantitative evaluation, and their distribution after ligation reaction, also providing an estimate of the degree of hydration of the objects. Such investigation is of particular biological relevance and provides the simplest yet model system for direct investigation of RNA reactions by advanced microscopy.

  11. Generating site-specifically modified proteins via a versatile and stable nucleophilic carbon ligation.

    PubMed

    Kudirka, Romas; Barfield, Robyn M; McFarland, Jesse; Albers, Aaron E; de Hart, Gregory W; Drake, Penelope M; Holder, Patrick G; Banas, Stefanie; Jones, Lesley C; Garofalo, Albert W; Rabuka, David

    2015-02-19

    There is a need for facile chemistries that allow for chemo- and regioselectivity in bioconjugation reactions. To address this need, we are pioneering site-specific bioconjugation methods that use formylglycine as a bioorthogonal handle on a protein surface. Here we introduce aldehyde-specific bioconjugation chemistry, the trapped-Knoevenagel ligation. The speed and stability of the trapped-Knoevenagel ligation further advances the repertoire of aldehyde-based bioconjugations and expands the toolbox for site-specific protein modifications. The trapped-Knoevenagel ligation reaction can be run at near neutral pH in the absence of catalysts to produce conjugates that are stable under physiological conditions. Using this new ligation, we generated an antibody-drug conjugate that demonstrates excellent efficacy in vitro and in vivo.

  12. Common Carotid Artery Ligation to Minimize Blood Loss During Oral and Maxillofacial Surgery.

    PubMed

    Goodman, Alice E; Goodman, Andrew R

    2016-09-01

    Oral and maxillofacial surgery in veterinary medicine carries the risk of severe hemorrhage due to the great vascular supply of the head. Temporary hemostasis can be achieved with the application of pressure or hemostatic agents, but more definitive treatment may be needed to ensure bleeding will not resume once the patient is awake and normotensive. (1 , 2) Actively bleeding vessels encountered during maxillofacial surgery may be inaccessible, and vessels may recoil into bone, sometimes preventing definitive ligation. These scenarios may require ligation of the common carotid artery. (1) The purpose of this paper is to describe how to perform ligation of the common carotid artery in a step-by-step fashion. Both temporary and permanent ligation techniques are described.

  13. Heated oligonucleotide ligation assay (HOLA): an affordable single nucleotide polymorphism assay.

    PubMed

    Black, W C; Gorrochotegui-Escalante, N; Duteau, N M

    2006-03-01

    Most single nucleotide polymorphism (SNP) detection requires expensive equipment and reagents. The oligonucleotide ligation assay (OLA) is an inexpensive SNP assay that detects ligation between a biotinylated "allele-specific detector" and a 3' fluorescein-labeled "reporter" oligonucleotide. No ligation occurs unless the 3' detector nucleotide is complementary to the SNP nucleotide. The original OLA used chemical denaturation and neutralization. Heated OLA (HOLA) instead uses a thermal stable ligase and cycles of denaturing and hybridization for ligation and SNP detection. The cost per genotype is approximately US$1.25 with two-allele SNPs or approximately US$1.75 with three-allele SNPs. We illustrate the development of HOLA for SNP detection in the Early Trypsin and Abundant Trypsin loci in the mosquito Aedes aegypti (L.) and at the a-glycerophosphate dehydrogenase locus in the mosquito Anopheles gambiae s.s.

  14. Western blot analysis of Src kinase assays using peptide substrates ligated to a carrier protein.

    PubMed

    Xu, Jie; Sun, Luo; Ghosh, Inca; Xu, Ming-Qun

    2004-06-01

    We have applied intein-mediated peptide ligation (IPL) to the use of peptide substrates for kinase assays and subsequent Western blot analysis. IPL allows for the efficient ligation of a synthetic peptide with an N-terminal cysteine residue to an intein-generated carrier protein containing a cysteine reactive C-terminal thioester through a native peptide bond. A distinct advantage of this procedure is that each carrier protein molecule ligates only one peptide, ensuring that the ligation product forms a sharp band on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). We demonstrate the effectiveness of this approach by mutational analysis of peptide substrates derived from human cyclin-dependent kinase, Cdc2, which contains a phosphorylation site of human c-Src protein tyrosine kinase.

  15. Chemoselective modifications for the traceless ligation of thioamide-containing peptides and proteins.

    PubMed

    Wang, Yanxin J; Szantai-Kis, D Miklos; Petersson, E James

    2016-07-14

    Thioamides are single-atom substitutions of canonical amide bonds, and have been proven to be versatile and minimally perturbing probes in protein folding studies. Previously, our group showed that thioamides can be incorporated into proteins by native chemical ligation (NCL) with Cys as a ligation handle. In this study, we report the expansion of this strategy into non-Cys ligation sites, utilizing radical initiated desulfurization to "erase" the side chain thiol after ligation. The reaction exhibited high chemoselectivity against thioamides, which can be further enhanced with thioacetamide as a sacrificial scavenger. As a proof-of-concept example, we demonstrated the incorporation of a thioamide probe into a 56 amino acid protein, the B1 domain of Protein G (GB1). Finally, we showed that the method can be extended to β-thiol amino acid analogs and selenocysteine.

  16. Interrupting Rivaling Access-flow with Nonsurgical Image-guided ligation: the "IRANI" Procedure.

    PubMed

    Cui, Jie; Freed, Robert; Liu, Fengyong; Irani, Zubin

    2015-01-01

    The presence of collateral veins is one of the most common causes of fistula failure to mature. The traditional approach to eliminate collateral vessel flow is coil embolization under fluoroscopy or surgical cut down and branch vessel ligation. However, both approaches are expensive and time consuming. Here, we described an image-guided nonsurgical method to ligate collateral veins. The collateral veins were ligated using Hawkins-Akins needle under ultrasound guidance. The average time for one ligation procedure was 17 minutes. There was a significant increase of blood flow in the venous outflow postligation procedure. Four weeks postprocedure ultrasound demonstrated occlusion of the target vessels. This procedure was well tolerated without major complications. In summary, the novel procedure described here offers an image-guided nonsurgical approach for collateral vein occlusion.

  17. Synthesis of cysteine-rich peptides by native chemical ligation without use of exogenous thiols.

    PubMed

    Tsuda, Shugo; Yoshiya, Taku; Mochizuki, Masayoshi; Nishiuchi, Yuji

    2015-04-03

    Native chemical ligation (NCL) performed without resorting to the use of thiol additives was demonstrated to be an efficient and effective procedure for synthesizing Cys-rich peptides. This method using tris(2-carboxyethyl)phosphine (TCEP) as a reducing agent facilitates the ligation reaction even at the Thr-Cys or Ile-Cys site and enables one-pot synthesis of Cys-rich peptides throughout NCL and oxidative folding.

  18. Combining ligation reaction and capillary gel electrophoresis to obtain reliable long DNA probes.

    PubMed

    García-Cañas, Virginia; Mondello, Monica; Cifuentes, Alejandro

    2011-05-01

    New DNA amplification methods are continuously developed for sensitive detection and quantification of specific DNA target sequences for, e.g. clinical, environmental or food applications. These new applications often require the use of long DNA oligonucleotides as probes for target sequences hybridization. Depending on the molecular technique, the length of DNA probes ranges from 40 to 450 nucleotides, solid-phase chemical synthesis being the strategy generally used for their production. However, the fidelity of chemical synthesis of DNA decreases for larger DNA probes. Defects in the oligonucleotide sequence result in the loss of hybridization efficiency, affecting the sensitivity and selectivity of the amplification method. In this work, an enzymatic procedure has been developed as an alternative to solid-phase chemical synthesis for the production of long oligonucleotides. The enzymatic procedure for probe production was based on ligation of short DNA sequences. Long DNA probes were obtained from smaller oligonucleotides together with a short sequence that acts as bridge stabilizing the molecular complex for DNA ligation. The ligation reactions were monitored by capillary gel electrophoresis with laser-induced fluorescence detection (CGE-LIF) using a bare fused-silica capillary. The capillary gel electrophoresis-LIF method demonstrated to be very useful and informative for the characterization of the ligation reaction, providing important information about the nature of some impurities, as well as for the fine optimization of the ligation conditions (i.e. ligation cycles, oligonucleotide and enzyme concentration). As a result, the yield and quality of the ligation product were highly improved. The in-lab prepared DNA probes were used in a novel multiplex ligation-dependent genome amplification (MLGA) method for the detection of genetically modified maize in samples. The great possibilities of the whole approach were demonstrated by the specific and sensitive

  19. Ligation-assisted endoscopic submucosal resection with circumferential mucosal incision for duodenal carcinoid tumor.

    PubMed

    Harada, Hideaki; Suehiro, Satoshi; Shimizu, Takanori; Katsuyama, Yasushi; Hayasaka, Kenji; Ito, Hideto

    2015-09-14

    Here we present the case of a 64-year-old female with a duodenal carcinoid tumor treated by ligation-assisted endoscopic submucosal resection (ESMR-L) with circumferential mucosal incision (CMI). Band ligation was effective in resecting the duodenal carcinoid tumor after CMI, with an uneventful post-procedural course. Histopathological examination showed clear tumor margins at deeper tissue levels. Thus, in the present case, ESMR-L with CMI was useful for the treatment of duodenal carcinoid tumor.

  20. Gold nanoparticle-enabled real-time ligation chain reaction for ultrasensitive detection of DNA.

    PubMed

    Shen, Wei; Deng, Huimin; Gao, Zhiqiang

    2012-09-12

    A simple and ultrasensitive colorimetric DNA assay based on the detection of the product of a ligation chain reaction (LCR) and the use of gold nanoparticles (AuNPs) as signal generators has been developed. During LCR, the AuNPs were ligated together, resulting in a distinct color change in real time after a sufficient number of thermal cycles. The cumulative nature of the protocol produced a detection limit of 20 aM with a selectivity factor of 10(3).

  1. Hypermutable ligation of plasmid DNA ends in cells from patients with Werner syndrome.

    PubMed

    Rünger, T M; Bauer, C; Dekant, B; Möller, K; Sobotta, P; Czerny, C; Poot, M; Martin, G M

    1994-01-01

    Werner Syndrome is a rare autosomal recessive disorder characterized by an increased cancer risk and by symptoms suggestive of premature aging. Cells from these patients demonstrate a typical pattern of chromosomal instability and a spontaneous hypermutability with a high rate of unusually large deletions. We have studied the in vivo DNA ligation in three lymphoblast cell lines from Werner syndrome patients and three from normal donors. In our host cell ligation assay we transfected linearized plasmid pZ189 and measured the amount of plasmid DNA ends rejoined by these host cells as the ability of the recovered plasmid to transform bacteria. A mutagenesis marker gene close to the ligation site allowed screening for mutations. Subsequent mutation analysis provided information about the accuracy of the ligation process. The cells from Werner syndrome patients were as effective as normal cells in ligating DNA ends. However, mutation analysis revealed that the three Werner syndrome cell lines introduced 2.4-4.6 times more mutations (p < 0.001) than the normal cell lines during ligation of the DNA ends: the mutation rates were 69.4, 97.2, and 58.7%, as compared to 23.6, 21.7, and 24.4% in the normal cell lines. These increased mutation frequencies in plasmids ligated during passage through Werner syndrome cells were mainly due to a significant (p < 0.001) increase in deletions. This error-prone DNA ligation might be responsible for the spontaneous hypermutability and the genomic instability in Werner syndrome cells and related to the apparently accelerated aging and high cancer risk in affected patients.

  2. Antibiotic Prophylaxis Using Third Generation Cephalosporins Can Reduce the Risk of Early Rebleeding in the First Acute Gastroesophageal Variceal Hemorrhage: A Prospective Randomized Study

    PubMed Central

    Jun, Chung-Hwan; Park, Chang-Hwan; Lee, Wan-Sik; Joo, Young-Eun; Kim, Hyun-Soo; Choi, Sung-Kyu; Rew, Jong-Sun; Kim, Sei-Jong

    2006-01-01

    Bacterial infection may be a critical trigger for variceal bleeding. Antibiotic prophylaxis can prevent rebleeding in patients with acute gastroesophageal variceal bleeding (GEVB). The aim of the study was to compare prophylactic third generation cephalosporins with on-demand antibiotics for the prevention of gastroesophageal variceal rebleeding. In a prospective trial, patients with the first acute GEVB were randomly assigned to receive prophylactic antibiotics (intravenous cefotaxime 2 g q 8 hr for 7 days, prophylactic antibiotics group) or to receive the same antibiotics only when infection became evident (on-demand group). Sixty-two patients in the prophylactic group and 58 patients in the on-demand group were included for analysis. Antibiotic prophylaxis decreased infection (3.2% vs. 15.5%, p=0.026). The actuarial rebleeding rate in the prophylactic group was significantly lower than that in the ondemand group (33.9% vs. 62.1%, p=0.004). The difference of rebleeding rate was mostly due to early rebleeding within 6 weeks (4.8% vs. 20.7%, p=0.012). On multivariate analysis, antibiotic prophylaxis (relative hazard: 0.248, 95% confidence interval (CI): 0.067-0.919, p=0.037) and bacterial infection (relative hazard: 3.901, 95% CI: 1.053-14.448, p=0.042) were two independent determinants of early rebleeding. In conclusion, antibiotic prophylaxis using third generation cephalosporins can prevent bacterial infection and early rebleeding in patients with the first acute GEVB. PMID:17043424

  3. An efficient ligation reaction promoted by a Varkud Satellite ribozyme with extended 5'- and 3'-termini.

    PubMed

    Jones, F D; Ryder, S P; Strobel, S A

    2001-12-15

    The Neurospora Varkud Satellite (VS) RNA is capable of promoting a reversible self-cleavage reaction important for its replication pathway. In vivo the VS RNA performs a cis-cleavage reaction to generate monomeric length transcripts that are subsequently ligated to produce circular VS RNA. The predominant form of VS RNA observed in vivo is the closed circular form, though minimal VS ribozyme self-cleavage constructs lack detectable ligation activity. MFOLD analysis of the entire VS RNA sequence revealed an extended region 5' and 3' of the minimal self-cleaving region that could anneal to form a complementary helix, which we have termed helix 7. In full-length VS RNA, this helix appears to span over 40 bp of sequence and brings the 5'- and 3'-ends of the RNA into proximity for the ligation reaction. Here we report a variant of the VS ribozyme with an extended 5'- and 3'-terminus capable of forming a truncated helix 7 that promotes the ligation reaction in vitro. Through mutation and selection of this RNA we have identified a ribozyme containing two point mutations in the truncated helix 7 that ligates with >70% efficiency. These results show that an additional helical element absent in current VS ribozyme constructs is likely to be important for the ligation activity of VS RNA.

  4. Electrochemical detection of point mutation based on surface ligation reaction and biometallization.

    PubMed

    Zhang, Peng; Chu, Xia; Xu, Xiangmin; Shen, Guoli; Yu, Ruqin

    2008-05-15

    A highly sensitive electrochemical method for point mutation detection based on surface enzymatic ligation reaction and biometallization is demonstrated. In this method the surface-immobilized allele-specific probe, complementary to the mutant target, undergoes allele-specific ligation with the 5'-phosphorylated ligation probe in the presence of the mutant oligonucleotide target and E. coli DNA ligase. If there is an allele mismatch, no ligation takes place. After thermal treatment at 90 degrees C, the formed duplex melts apart, which merely allows the ligation product to remain on the electrode surface. Then, biotinylated detection probes hybridize with the ligation product. With the binding of streptavidin-alkaline phosphatase (SA-ALP) to the biotinylated probes, a non-reductive substrate of alkaline phosphatase, ascorbic acid 2-phosphate (AA-P), can be converted into ascorbic acid (AA) at the electrode surface. Silver ions in solution are then reduced by AA, resulting in the deposition of silver metal onto the electrode surface. Linear sweep voltammetry (LSV) is used to detect the amount of deposited silver. The proposed approach has been successfully implemented for the identification of single base mutation in codon 12 of K-ras oncogene target with a detection limit of 80fM, demonstrating that this method provides a highly specific, sensitive and cost-efficient approach for point mutation detection.

  5. Insights into the mechanism and catalysis of the native chemical ligation reaction.

    PubMed

    Johnson, Erik C B; Kent, Stephen B H

    2006-05-24

    Native chemical ligation of unprotected peptide segments involves reaction between a peptide-alpha-thioester and a cysteine-peptide, to yield a product with a native amide bond at the ligation site. Peptide-alpha-thioalkyl esters are commonly used because of their ease of preparation. These thioalkyl esters are rather unreactive so the ligation reaction is catalyzed by in situ transthioesterification with thiol additives. The most common thiol catalysts used to date have been either a mixture of thiophenol/benzyl mercaptan, or the alkanethiol MESNA. Despite the use of these thiol catalysts, ligation reactions typically take 24-48 h. To gain insight into the mechanism of native chemical ligaton and in order to find a better catalyst, we investigated the use of a number of thiol compounds. Substituted thiophenols with pK(a) > 6 were found to best combine the ability to exchange rapidly and completely with thioalkyl esters, and to then act as effective leaving groups in reaction of the peptide-thioester with the thiol side chain of a cysteine-peptide. A highly effective and practical catalyst was (4-carboxylmethyl)thiophenol ('MPAA'), a nonmalodorous, water-soluble thiol. Use of MPAA gave an order of magnitude faster reaction in model studies of native chemical ligation and in the synthesis of a small protein, turkey ovomucoid third domain (OMTKY3). MPAA should find broad use in native chemical ligation and in the total synthesis of proteins.

  6. Effects of 2'-O-methyl nucleotide on ligation capability of T4 DNA ligase.

    PubMed

    Zhao, Bin; Tong, Zhaoxue; Zhao, Guojie; Mu, Runqing; Shang, Hong; Guan, Yifu

    2014-09-01

    To further understand the ligation mechanism, effects of 2'-O-methyl nucleotide (2'-OMeN) on the T4 DNA ligation efficiency were investigated. Fluorescence resonance energy transfer assay was used to monitor the nick-joining process by T4 DNA ligase. Results showed that substitutions at 5'- and 3'-ends of the nick decreased the ligation efficiency by 48.7% ± 6.7% and 70.6% ± 4.0%, respectively. Substitutions at both 5'- and 3'-ends decreased the ligation efficiency by 76.6% ± 1.3%. Corresponding kinetic parameters, Vmax, Km, and kcat, have been determined in each case by using the Michaelis-Menten equation. The kinetic data showed that the 2'-OMeN substitutions reduced the maximal initial velocity and increased the Michaelis constant of T4 DNA ligase. Mismatches at 5'- and 3'-ends of the nick have also shown different influences on the ligation. Results here showed that the sugar pucker conformation at 3'-end impairs the ligation efficiency more profoundly than that at 5'-end. Different concentrations of Mg(2+), Ca(2+), K(+), Na(+), and ATP were also demonstrated to affect the T4 DNA ligase activity. These results enriched our knowledge about the effects of 2'-OMeN substitutions on the T4 DNA ligase.

  7. Chemical Ligation of Folded Recombinant Proteins: Segmental Isotopic Labeling of Domains for NMR Studies

    NASA Astrophysics Data System (ADS)

    Xu, Rong; Ayers, Brenda; Cowburn, David; Muir, Tom W.

    1999-01-01

    A convenient in vitro chemical ligation strategy has been developed that allows folded recombinant proteins to be joined together. This strategy permits segmental, selective isotopic labeling of the product. The src homology type 3 and 2 domains (SH3 and SH2) of Abelson protein tyrosine kinase, which constitute the regulatory apparatus of the protein, were individually prepared in reactive forms that can be ligated together under normal protein-folding conditions to form a normal peptide bond at the ligation junction. This strategy was used to prepare NMR sample quantities of the Abelson protein tyrosine kinase-SH(32) domain pair, in which only one of the domains was labeled with 15N Mass spectrometry and NMR analyses were used to confirm the structure of the ligated protein, which was also shown to have appropriate ligand-binding properties. The ability to prepare recombinant proteins with selectively labeled segments having a single-site mutation, by using a combination of expression of fusion proteins and chemical ligation in vitro, will increase the size limits for protein structural determination in solution with NMR methods. In vitro chemical ligation of expressed protein domains will also provide a combinatorial approach to the synthesis of linked protein domains.

  8. Protein-templated fragment ligations - from molecular recognition to drug discovery.

    PubMed

    Jaegle, Mike; Wong, Ee Lin; Tauber, Carolin; Nawrotzky, Eric; Arkona, Christoph; Rademann, Jörg

    2017-01-24

    The understanding and manipulation of molecular recognition events is the key to modern approaches in drug discovery. Protein-templated fragment ligation is a novel concept to support drug discovery and can help to improve the efficacy of already existing protein ligands. Protein-templated fragment ligations are chemical reactions between small molecules ("fragments") that utilize a protein´s surface as a template to combine and to form a protein ligand with increased binding affinity. The approach exploits the molecular recognition of reactive small molecule fragments by proteins both for ligand assembly and for the identification of bioactive fragment combinations. Chemical synthesis and bioassay are thus integrated in one single step. In this article we portrait the biophysical basis of reversible and irreversible fragment ligations and the available methods to detect protein-templated ligation products. The scope of known chemical reactions providing templated ligation products is reviewed and the possibilities to extend the reaction portfolio are discussed. Selected recent applications of the method in protein ligand discovery are reported. Finally, the strengths and limitations of the concept are discussed and an outlook on the future impact of templated fragment ligations on the drug discovery process is given.

  9. Prospective comparison of ligation and bipolar cautery technique in non-scalpel vasectomy

    PubMed Central

    Altok, Muammer; Şahin, Ali Feyzullah; Divrik, Rauf Taner; Yildirim, Ümit; Zorlu, Ferruh

    2015-01-01

    ABSTRACT Objectives: There is no trial comparing bipolar cautery and ligation for occlusion of vas in non-scalpel vasectomy. This study aimed to compare the effectiveness of these vasectomy occlusion techniques. Materials and Methods: Between January 2002-June 2009, patients were allocated in alternate order. We recruited 100 cases in cautery group and 100 cases in ligation group. Non-scalpel approach was performed during vasectomy and fascial interposition was performed in all cases. First semen analysis was done 3 months after vasectomy. Vasectomy success was defined as azoospermia or non-motile sperm lower than 100.000/mL. Results: Four patients from the cautery group were switched to the ligation group due to technical problem of cautery device. Thus, data of 96 patients as cautery group and 104 patients as ligation group were evaluated. After vasectomy, semen analyses were obtained from 59 of 96 (61.5%) patients in cautery group and to 66 of 104 (63.5%) patients in ligation group. There was no statistical significant difference between the two groups in terms of the success of vasectomy (p=0.863). Conclusion: Although bipolar cautery technique is safe, effective and feasible in non-scalpel vasectomy, it has no superiority to ligation. There was no statistically significant difference in terms of the success and complications between the two groups. PMID:26742977

  10. Blood flow changes after unilateral carotid artery ligation monitored by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Ma, Yushu; Liang, Chengbo; Suo, Yanyan; Zhao, Yuqian; Wang, Yi; Xu, Tao; Wang, Ruikang; Ma, Zhenhe

    2016-03-01

    Unilateral carotid artery ligation which could induce adaptive improvement is a classic model that has been widely used to study pathology of ischemic disease. In those studies, blood flow is an important parameter to characterize the ischemia. Optical coherence tomography (OCT) is a powerful imaging modality which can provide depth resolved images in biological tissue with high spatial and temporal resolution. SPF rats was anesthetized with isoflurane and divided into two groups. In first group, bilateral carotid artery was surgically exposed, and then left carotid artery was ligated. Blood flow changes of the contralateral carotid artery was monitored using high speed spectral domain optical coherence tomography, including the absolute flow velocity and the flow volume. In the other group, skull window was opened at the ipsilateral cerebral cortex of ligation and blood supply of small artery was measured before and after the ligation. The measured results demonstrate the blood supply compensation process after unilateral carotid artery ligation. With the superiority of high resolution, OCT is an effective technology in monitoring results of carotid artery after ligation.

  11. A novel, one-step amplification and oligonucleotide ligation procedure for multiplex genetic typing

    SciTech Connect

    Eggerding, F.A.

    1994-09-01

    A new technique, coupled amplification and oligonucleotide ligation (CAL), has been developed for simultaneous multiplex amplification and genotyping of DNA. CAL is a biphasic method which combines in one assay DNA amplification by the polymerase chain reaction (PCR) with DNA genotyping by the oligonucleotide ligation assay (OLA). By virtue of a difference in the melting temperatures of PCR primer-target DNA and OLA probe-target DNA hybrids, the method allows preferential amplification of DNA during stage I and oligonucleotide ligation during stage II of the reaction. In stage I target DNA is amplified using high-melting primers in a two-step PCR cycle that employs a 72{degrees}C anneal-elongation step. In stage II genotyping of PCR products by competitive oligonucleotide ligation with oligonucleotide probes located between PCR primers is accomplished by several cycles of denaturation at 94{degrees}C followed by anneal-ligation at 55{degrees}C. Ligation products are fluorochrome-labeled at their 3{prime}-ends and analyzed electrophoretically on a fluorescent DNA sequencer. The CAL procedure has been used for multiplex detection of 30 cystic fibrosis mutations and for analysis of ras gene point mutations. Because mutation detection occurs concurrently with target amplification, the technique is rapid, highly sensitive and specific, easily automatable, and requires minimal sample processing.

  12. Formation of oligonucleotide-PNA-chimeras by template-directed ligation

    NASA Technical Reports Server (NTRS)

    Koppitz, M.; Nielsen, P. E.; Orgel, L. E.; Bada, J. L. (Principal Investigator)

    1998-01-01

    DNA sequences have previously been reported to act as templates for the synthesis of PNA, and vice versa. A continuous evolutionary transition from an informational replicating system based on one polymer to a system based on the other would be facilitated if it were possible to form chimeras, that is molecules that contain monomers of both types. Here we show that ligation to form chimeras proceeds efficiently both on PNA and on DNA templates. The efficiency of ligation is primarily determined by the number of backbone bonds at the ligation site and the relative orientation of template and substrate strands. The most efficient reactions result in the formation of chimeras with ligation junctions resembling the structures of the backbones of PNA and DNA and with antiparallel alignment of both components of the chimera with the template, that is, ligations involving formation of 3'-phosphoramidate and 5'-ester bonds. However, double helices involving PNA are stable both with antiparallel and parallel orientation of the two strands. Ligation on PNA but not on DNA templates is, therefore, sometimes possible on templates with reversed orientation. The relevance of these findings to discussions of possible transitions between genetic systems is discussed.

  13. Frictional evaluations of dental typodont models using four self-ligating designs and a conventional design.

    PubMed

    Henao, Sandra P; Kusy, Robert P

    2005-01-01

    Abstract: After a previous study using typodonts and three standardized archwire (AW) sizes, the frictional evaluations of four self-ligating brackets were directed toward the optimal AW-bracket system. Four participating manufacturers suggested three AWs, which were a representation of the three stages of orthodontic treatment, to be coupled with their respective self-ligating design. Four replicated typodont models were mounted with a self-ligating design, and a fifth model was mounted with a conventional design that served as a control. The first experiment evaluated the manufacturer-suggested AWs against the respective self-ligating design. Because no third-stage AWs could engage their respective designs, a second experiment was implemented to gain more detailed analyses of the designs. This experiment included any successful manufacturer-suggested AWs from the first experiment against the four self-ligating designs and the control design. All self-ligating designs performed with the efficiency and reproducibility associated with expectations. Specifically, self-ligation outperformed the conventional brackets when coupled with up to 0.020- x 0.020-inch wires. The clearance of the various AW sizes and alloys changed with malocclusion. Furthermore, the parameter that best correlated with drawing forces was the bending stiffness of the AW, which was directly associated with the nominal dimension of each wire. The best AW-bracket system can be selected, when taking into account the stiffness (elastic modulus and size of the AW) along with the amount of malocclusion present, once the treatment plan is determined.

  14. Complement component C5 deficiency reduces edema formation in murine ligation-induced acute pancreatitis.

    PubMed

    Merriam, L T; Webster, C; Joehl, R J

    1997-01-01

    The complement cascade is activated in humans and animals with acute pancreatitis. Activation of complement component C5 liberates C5a, C5a-desarg, and terminal complement complexes (TCCs) that increase capillary permeability, edema, and leukocyte chemotaxis at injured sites. Complement activation plays a major role in pathogenesis of capillary leak and edema formation in severe acute pancreatitis; however, the contribution of C5 (C5a/C5a-desarg, TCCs) has not been defined. Using He gene mutant mice lacking circulating C5, the role of C5 in ligation-induced acute pancreatitis was evaluated. We performed the following experiments: C5-sufficient (Hc1/Hc1) and C5-deficient (Hc0/Hc0) mice had bile and pancreatic ducts ligated. Sham-operated mice had ducts dissected but not ligated. Mice were killed at 4, 8, and 24 hr after bilepancreatic duct ligation. Serologic and morphologic evidences of acute pancreatitis were evaluated. Pancreatic edema was assessed using analysis of pancreatic water content, histologic edema score, and determination of wet weight ratio. After 4, 8, and 24 hr of bile-pancreatic duct ligation, hyperamylasemia and histologic changes of acute pancreatitis were observed in both C5-deficient and C5-sufficient mice. Edema developed in all mice with acute pancreatitis. However, when compared to C5-sufficient mice, mice deficient in C5 developed significantly less pancreatic edema at both 8 and 24 hr of bile-pancreatic duct ligation. This difference was not observed 4 hr after induction of acute pancreatitis. We conclude that C5 contributes to edema formation in murine ligation-induced acute pancreatitis. The presence of an early C5-independent phase, in conjunction with the observation of significant edema in mice deficient in C5, suggests there are other mediators of edema formation in this acute pancreatitis model.

  15. EARLY MARKERS OF REGENERATION FOLLOWING DUCTAL LIGATION IN THE RAT SUBMANDIBULAR GLAND

    PubMed Central

    Cotroneo, Emanuele; Proctor, Gordon B.; Paterson, Katherine L.; Carpenter, Guy H.

    2008-01-01

    Rat submandibular glands can recover their function and secretory protein content following ductal ligation-induced atrophy. Morphological studies have established that following ligation, deligation of the gland regenerates new salivary gland tissue. However, little is know about changes happening during early regeneration following intra-oral duct ligation, which does not damage the parasympathetic nerves. Gland that had been 2 weeks ligated or 2 weeks ligated + 3 days deligation glands were compared. Tissue was prepared for histological, immunohistochemical (SMG-B and Ki 67) and immunocytochemical analyses (smooth muscle actin, aquaporin 5). H&E staining of deligated glands showed some acini have regained their cytoplasmic volume; moreover, the loss of AB/PAS staining from the lumen of ducts suggested successful deligation. The deligated gland was characterized by atypical acinar-ductal branched structures, which were less frequent in the ligated gland and rarely seen in normal unoperated tissue. Myoepithelial cells were also investigated since changes in their morphology reflected changes in the acini morphology not readily detected by conventional staining. Actin staining revealed the presence of some shrunken acini in the atrophic tissue whereas they had regained their normal morphology in the deligated gland suggesting the acini were recovering. Some acini during deligation regained aquaporin 5 expression which was decreased during atrophy. Furthermore SMG-B protein, located in the pro-acinar cell during gland development and usually located in the intercalated duct cells in the adult, has been detected in the newly formed acini of the deligated gland. This study suggests that morphological markers of regeneration are apparent after just 3 days following ligation removal. PMID:18335244

  16. Selective desulfurization of cysteine in the presence of Cys(Acm) in polypeptides obtained by native chemical ligation.

    PubMed

    Pentelute, Brad L; Kent, Stephen B H

    2007-02-15

    Increased versatility for the synthesis of proteins and peptides by native chemical ligation requires the ability to ligate at positions other than Cys. Here, we report that Raney nickel can be used under standard conditions for the selective desulfurization of Cys in the presence of Cys(Acm). This simple and practical tactic enables the more common Xaa-Ala junctions to be used as ligation sites for the chemical synthesis of Cys-containing peptides and proteins. [reaction: see text].

  17. An oxazetidine amino acid for chemical protein synthesis by rapid, serine-forming ligations

    NASA Astrophysics Data System (ADS)

    Pusterla, Ivano; Bode, Jeffrey W.

    2015-08-01

    Amide-forming ligation reactions allow the chemical synthesis of proteins by the union of unprotected peptide segments, and enable the preparation of protein derivatives not accessible by expression or bioengineering approaches. The native chemical ligation (NCL) of thioesters and N-terminal cysteines is unquestionably the most successful approach, but is not ideal for all synthetic targets. Here we describe the synthesis of an Fmoc-protected oxazetidine amino acid for use in the α-ketoacid-hydroxylamine (KAHA) amide ligation. When incorporated at the N-terminus of a peptide segment, this four-membered cyclic hydroxylamine can be used for rapid serine-forming ligations with peptide α-ketoacids. This ligation operates at low concentration (100 μM-5 mM) and mild temperatures (20-25 °C). The utility of the reaction was demonstrated by the synthesis of S100A4, a 12 kDa calcium-binding protein not easily accessible by NCL or other amide-forming reactions due to its primary sequence and properties.

  18. Nucleosome linker proteins HMGB1 and histone H1 differentially enhance DNA ligation reactions.

    PubMed

    Yamanaka, Shiho; Katayama, Eisaku; Yoshioka, Ken-ichi; Nagaki, Sumiko; Yoshida, Michiteru; Teraoka, Hirobumi

    2002-03-22

    We previously reported that HMGB1, which originally binds to chromatin in a manner competitive with linker histone H1 to modulate chromatin structure, enhances both intra-molecular and inter-molecular ligations. In this paper, we found that histone H1 differentially enhances ligation reaction of DNA double-strand breaks (DSB). Histone H1 stimulated exclusively inter-molecular ligation reaction of DSB with DNA ligase IIIbeta and IV, whereas HMGB1 enhanced mainly intra-molecular ligation reaction. Electron microscopy of direct DNA-protein interaction without chemical cross-linking visualized that HMGB1 bends and loops linear DNA to form compact DNA structure and that histone H1 is capable of assembling DNA in tandem arrangement with occasional branches. These results suggest that differences in the enhancement of DNA ligation reaction are due to those in alteration of DNA configuration induced by these two linker proteins. HMGB1 and histone H1 may function in non-homologous end-joining of DSB repair and V(D)J recombination in different manners.

  19. Air-powder polishing on self-ligating brackets after clinical use: effects on debris levels

    PubMed Central

    Aragón, Mônica L. S. Castro; Lima, Leandro Santiago; Normando, David

    2016-01-01

    ABSTRACT Introduction: Debris buildup on brackets and arch surfaces is one of the main factors that can influence the intensity of friction between bracket and orthodontic wire. Objective: This study sought to evaluate the effect of air-powder polishing cleaning on debris levels of self-ligating ceramic brackets at the end of orthodontic treatment, compared to the behavior of conventional brackets. Methods: Debris levels were evaluated in metal conventional orthodontic brackets (n = 42) and ceramic self-ligating brackets (n = 42) on canines and premolars, arranged in pairs. There were brackets with and without air-powder polishing. At the end of orthodontic treatment, a hemiarch served as control and the contralateral hemiarch underwent prophylaxis with air-powder polishing. Debris buildup in bracket slots was assessed through images, and Wilcoxon test was used to analyze the results. Results: The median debris levels were statistically lower in the conventional metal brackets compared to self-ligating ones (p = 0.02), regarding brackets not submitted to air-powder polishing. Polishing significantly reduced debris buildup to zero in both systems, without differences between groups. Conclusions: Ceramic self-ligating brackets have a higher debris buildup in comparison to conventional metal brackets in vivo, but prophylaxis with sodium bicarbonate jet was effective in reducing debris levels in self-ligating and also in conventional brackets. PMID:27901234

  20. Feeding practices and patent ductus arteriosus ligation preferences-are they related?

    PubMed

    Jhaveri, Nami; Soll, Roger F; Clyman, Ronald I

    2010-09-01

    We hypothesized that there is a significant relationship between a neonatologist's belief that feedings must be stopped in the presence of a patent ductus arteriosus (PDA) and his or her willingness to ligate a PDA. We administered the same survey questionnaire to two separate populations of neonatologists to assess their beliefs regarding PDA treatment practices. Although >90% of U.S. and non-U.S. neonatologists reported that they would ligate a PDA when infants with birth weights <900 g required mechanical ventilation (and indomethacin was contraindicated or had failed to close the PDA), U.S. neonatologists reported that they were significantly more likely to ligate a PDA when less respiratory support was required. U.S. neonatologists were also more likely to stop feedings when a PDA was present. The reported likelihood that a neonatologist would ligate a PDA in infants who did not require mechanical ventilation was significantly increased if the neonatologist believed that feedings had to be stopped because of the PDA. After controlling for the belief that "feedings must be stopped in the presence of a PDA," the significant difference between U.S. and non-U.S. neonatologists, in their reported desire to ligate infants who did not require mechanical ventilation, was no longer present.

  1. No Scalpel Vasectomy (NSV) with Ligation and Excision: A Single Centre Experience.

    PubMed

    Bhuyan, K; Ali, I; Sarma, G; Das, U

    2015-12-01

    No scalpel vasectomy (NSV) has proved to be a safe and simple procedure for permanent sterilization for men. Ligation and excision of the vas deferens followed by fascial interposition is the procedure of choice. It is believed that vas excision without fascial interposition has a risk of failure. The objective of this study was to evaluate the technique of NSV with ligation and excision only. No scalpel vasectomy performed in an urban centre was taken for this prospective study. Only ligation and excision procedure was applied in its execution. It was demonstrated and performed under the supervision of an expert. Information regarding early and late complications including failure was gathered. A total number of 3,392 NSVs were performed in an urban training centre between Apr' 2009 to Mar' 2013. The procedure applied was only excision and ligation of the vas deferens. The fascial interposition was not included in the procedure. Haematoma (1), bleeding (3), foreign body granuloma (1), scrotal pain (3), epididymitis (1) and sinus formations (1) were encountered. There was only one failure in the whole group of acceptors. NSV with ligation and excision is a simple and easy procedure to learn and perform. Complications and failures are negligible. The additional fascial interposition needs more surgical skill and is time-consuming, hence can be avoided where a large number of acceptors need to undergo NSV in a rural camp.

  2. A Relaxed Active Site After Exon Ligation by the Group I Intron

    SciTech Connect

    Lipchock,S.; Strobel, S.

    2008-01-01

    During RNA maturation, the group I intron promotes two sequential phosphorotransfer reactions resulting in exon ligation and intron release. Here, we report the crystal structure of the intron in complex with spliced exons and two additional structures that examine the role of active-site metal ions during the second step of RNA splicing. These structures reveal a relaxed active site, in which direct metal coordination by the exons is lost after ligation, while other tertiary interactions are retained between the exon and the intron. Consistent with these structural observations, kinetic and thermodynamic measurements show that the scissile phosphate makes direct contact with metals in the ground state before exon ligation and in the transition state, but not after exon ligation. Despite no direct exonic interactions and even in the absence of the scissile phosphate, two metal ions remain bound within the active site. Together, these data suggest that release of the ligated exons from the intron is preceded by a change in substrate-metal coordination before tertiary hydrogen bonding contacts to the exons are broken.

  3. The role of reactivity in DNA templated native chemical PNA ligation during PCR.

    PubMed

    Roloff, Alexander; Seitz, Oliver

    2013-06-15

    DNA templated fluorogenic reactions have been used as a diagnostic tool for the sequence specific detection of nucleic acids; and it has been shown that the native chemical ligation between thioester- and 1,2-aminothiol-modified PNA probes is amongst the most selective DNA detection methods reported. We explored whether a DNA templated reaction can be interfaced with the polymerase chain reaction (PCR). This endeavor posed a significant challenge. The reactive groups involved must be sufficiently stable to tolerate the high temperature applied in the PCR process. Nevertheless, the ligation reaction must proceed very rapidly and sequence specifically within the short time available in the annealing and primer extension steps before denaturation is used after approx. 1 min to commence the next PCR cycle. This required a careful optimization of the ternary complex architecture as well as adjustments of probe length and probe reactivities. Our results point to the prime importance of the ligation architecture. We show that once suitable annealing sites have been identified less reactive probe sets may be preferable if sequence specificity is of major concern. The reactivity tuning enabled the development of an in-PCR ligation, which was used for the single nucleotide specific typing of the V600E (T1799A) point mutation in the human BRaf gene. Showcasing the efficiency and sequence specificity of native chemical PNA ligation, attomolar template proofed sufficient to trigger signal while a 1000-fold higher load of single mismatched template failed to induce appreciable signal.

  4. Measurements of the torque moment in various archwire-bracket-ligation combinations.

    PubMed

    Hirai, Miyuki; Nakajima, Akira; Kawai, Nobuhiko; Tanaka, Eiji; Igarashi, Yu; Sakaguchi, Masahito; Sameshima, Glenn T; Shimizu, Noriyoshi

    2012-06-01

    The torque moment generated by third-order bends is important for tooth movement. The purpose of this study was to measure the torque moment that can be delivered by various archwire and bracket combinations at the targeted tooth. Stainless steel (SS) upper brackets with 0.018 and 0.022 inch slots, two sizes of nickel-titanium (Ni-Ti) alloy wires, and three sizes of SS wires for each bracket were used. The wire was ligated with elastics or wire. The torque moment delivered by the various archwire-bracket-ligation combinations was measured using a torque gauge. Statistical analysis was undertaken using analysis of variance (multiple comparison tests and post hoc using Tukey's honestly significant difference test. The torque moment increased as the degree of torque and wire size increased. There was no significant difference in torque moment between the SS and Ni-Ti wires at lower or higher than 40 degrees torque. The torque moment with wire ligation was significantly larger than that with elastic ligation with 0.016 × 0.022 and 0.017 × 0.025 inch Ni-Ti wires in the 0.018 inch slot brackets and the 0.017 × 0.025 and 0.019 × 0.025 inch SS and Ni-Ti wires in the 0.022 inch slot brackets. However, there was no significant difference in torque moment between either ligation method when using the full slot size wires.

  5. A comparison of the Ameroid constrictor versus ligation in the surgical management of single extrahepatic portosystemic shunts.

    PubMed

    Murphy, S T; Ellison, G W; Long, M; Van Gilder, J

    2001-01-01

    Twenty-two dogs were managed surgically for a single extrahepatic portosystemic shunt; 12 with surgical ligation and 10 with an Ameroid constrictor. Utilization of the Ameroid constrictor significantly decreased surgery time to approximately half that of the ligation technique. A decreased intraoperative and postoperative complication rate was noted with the Ameroid constrictor group. Follow-up evaluation demonstrated comparable efficacy when comparing surgical techniques. The Ameroid constrictor offered a surgical occlusion technique for management of a single extra-hepatic portosystemic shunt that was equally effective to ligation while shortening surgical time and minimizing the risks that are commonly associated with ligation of the shunting vessel.

  6. Influence of polyethylene glycol on the ligation reaction with calf thymus DNA ligases I and II.

    PubMed

    Teraoka, H; Tsukada, K

    1987-01-01

    High concentrations of the nonspecific macromolecule polyethylene glycol 6000 (PEG 6000) enabled DNA ligases I and II from calf thymus to catalyze intermolecular blunt-end ligation of duplex DNA. Intermolecular cohesive-end ligation with these enzymes was markedly stimulated in the presence of 10-16% (w/v) PEG 6000. The effect of PEG 6000 (4-16%) on the sealing of single-stranded breaks in duplex DNA with DNA ligases I and II was not appreciably stimulatory but rather inhibitory. PEG 6000 (15%) enhanced more twofold the rate of DNA ligase II-AMP complex formation, but moderately suppressed the rate of formation of DNA ligase 1-AMP complex. Polyamines and KCl inhibited blunt-end and cohesive-end ligations with DNA ligases I and II in the presence of PEG 6000.

  7. Ligation versus bipolar diathermy for hemostasis in tonsillectomy: a comparative study.

    PubMed

    Sharma, Karan; Kumar, Devinder

    2011-01-01

    Tonsillectomy despite being less performed nowadays still is a very common surgery performed by ENT surgeons. The use of various modalities like bipolar diathermy, laser, cryosurgery, radiofrequency and ionic coblation for hemostasis in tonsillectomy remains controversial so far. A thorough scan of literature comparing the ligation with diathermy has been presented. In this prospective study, we analysed 50 patients undergoing tonsillectomy by dissection method. Right sided tonsillectomies act as study group (bipolar diathermy used) and left sided tonsillectomies as the control group (ligation for hemostasis used). The aim of our study is to compare the amount of blood loss, number of ligatures applied, average time taken and incidence of postoperative haemorrhage following the use of ligation and bipolar diathermy. The study found that diathermy hemostatic technique is associated with a quicker procedure, less intraoperative blood loss, comparable postoperative pain.

  8. Expressed Protein Ligation: A Resourceful Tool to Study Protein Structure and Function

    PubMed Central

    Berrade, Luis; Camarero, Julio A.

    2013-01-01

    This review outlines the use of expressed protein ligation (EPL) to study protein structure, function and stability. EPL is a chemoselective ligation method that allows the selective ligation of unprotected polypeptides from synthetic and recombinant origin for the production of semi-synthetic protein samples of well-defined and homogeneous chemical composition. This method has been extensively used for the site-specific introduction of biophysical probes, unnatural amino acids, and increasingly complex post-translational modifications. Since it was introduced 10 years ago, EPL applications have grown increasingly more sophisticated in order to address even more complex biological questions. In this review we highlight how this powerful technology combined with standard biochemical analysis techniques has been used to improve our ability to understand protein structure and function. PMID:19685006

  9. Ligation reaction specificities of an NAD(+)-dependent DNA ligase from the hyperthermophile Aquifex aeolicus.

    PubMed

    Tong, J; Barany, F; Cao, W

    2000-03-15

    An NAD(+)-dependent DNA ligase from the hyperthermophilic bacterium Aquifex aeolicus was cloned, expressed in Escherichia coli and purified to homogeneity. The enzyme is most active in slightly alkaline pH conditions with either Mg(2+)or Mn(2+)as the metal cofactor. Ca(2+)and Ni(2+)mainly support formation of DNA-adenylate intermediates. The catalytic cycle is characterized by a low k (cat)value of 2 min(-1)with concomitant accumulation of the DNA - adenylate intermediate when Mg(2+)is used as the metal cofactor. The ligation rates of matched substrates vary by up to 4-fold, but exhibit a general trend of T/A < or = G/C < C/G < A/T on both the 3'- and 5'-side of the nick. Consistent with previous studies on Thermus ligases, this Aquifex ligase exhibits greater discrimination against a mismatched base pair on the 3'-side of the nick junction. The requirement of 3' complementarity for a ligation reaction is reaffirmed by results from 1 nt insertions on either the 3'- or 5'-side of the nick. Furthermore, most of the unligatable 3' mismatched base pairs prohibit formation of the DNA-adenylate intermediate, indicating that the substrate adenylation step is also a control point for ligation fidelity. Unlike previously studied ATP ligases, gapped substrates cannot be ligated and intermediate accumulation is minimal, suggesting that complete elimination of base pair complementarity on one side of the nick affects substrate adenylation on the 5'-side of the nick junction. Relationships among metal cofactors, ligation products and intermediate, and ligation fidelity are discussed.

  10. Isolation of novel ribozymes that ligate AMP-activated RNA substrates

    NASA Technical Reports Server (NTRS)

    Hager, A. J.; Szostak, J. W.

    1997-01-01

    BACKGROUND: The protein enzymes RNA ligase and DNA ligase catalyze the ligation of nucleic acids via an adenosine-5'-5'-pyrophosphate 'capped' RNA or DNA intermediate. The activation of nucleic acid substrates by adenosine 5'-monophosphate (AMP) may be a vestige of 'RNA world' catalysis. AMP-activated ligation seems ideally suited for catalysis by ribozymes (RNA enzymes), because an RNA motif capable of tightly and specifically binding AMP has previously been isolated. RESULTS: We used in vitro selection and directed evolution to explore the ability of ribozymes to catalyze the template-directed ligation of AMP-activated RNAs. We subjected a pool of 10(15) RNA molecules, each consisting of long random sequences flanking a mutagenized adenosine triphosphate (ATP) aptamer, to ten rounds of in vitro selection, including three rounds involving mutagenic polymerase chain reaction. Selection was for the ligation of an oligonucleotide to the 5'-capped active pool RNA species. Many different ligase ribozymes were isolated; these ribozymes had rates of reaction up to 0.4 ligations per hour, corresponding to rate accelerations of approximately 5 x10(5) over the templated, but otherwise uncatalyzed, background reaction rate. Three characterized ribozymes catalyzed the formation of 3'-5'-phosphodiester bonds and were highly specific for activation by AMP at the ligation site. CONCLUSIONS: The existence of a new class of ligase ribozymes is consistent with the hypothesis that the unusual mechanism of the biological ligases resulted from a conservation of mechanism during an evolutionary replacement of a primordial ribozyme ligase by a more modern protein enzyme. The newly isolated ligase ribozymes may also provide a starting point for the isolation of ribozymes that catalyze the polymerization of AMP-activated oligonucleotides or mononucleotides, which might have been the prebiotic analogs of nucleoside triphosphates.

  11. Ku stimulation of DNA ligase IV-dependent ligation requires inward movement along the DNA molecule.

    PubMed

    Kysela, Boris; Doherty, Aidan J; Chovanec, Miroslav; Stiff, Thomas; Ameer-Beg, Simon M; Vojnovic, Borivoj; Girard, Pierre-Marie; Jeggo, Penny A

    2003-06-20

    The DNA ligase IV.XRCC4 complex (LX) functions in DNA non-homologous-end joining, the main pathway for double-strand break repair in mammalian cells. We show that, in contrast to ligation by T4 ligase, the efficiency of LX ligation of double-stranded (ds) ends is critically dependent upon the length of the DNA substrate. The effect is specific for ds ligation, and LX/DNA binding is not influenced by the substrate length. Ku stimulates LX ligation at concentrations resulting in 1-2 Ku molecules bound per substrate, whereas multiply Ku-bound DNA molecules inhibit ds ligation. The combined footprint of DNA with Ku and LX bound is the sum of each individual footprint suggesting that the two complexes are located in tandem at the DNA end. Inhibition of Ku translocation by the presence of cis-platinum adducts on the DNA substrate severely inhibits ligation by LX. Fluorescence resonance energy transfer analysis using fluorophore-labeled Ku and DNA molecules showed that, as expected, Ku makes close contact with the DNA end and that addition of LX can disrupt this close contact. Finally, we show that recruitment of LX by Ku is impaired in an adenylation-defective mutant providing further evidence that LX interacts directly with the DNA end, possibly via the 5'-phosphate as shown for prokaryotic ligases. Taken together, our results suggest that, when LX binds to a Ku-bound DNA molecule, it causes inward translocation of Ku and that freedom to move inward on the DNA is essential to Ku stimulation of LX activity.

  12. Diagnostic Accuracy of APRI, AAR, FIB-4, FI, and King Scores for Diagnosis of Esophageal Varices in Liver Cirrhosis: A Retrospective Study.

    PubMed

    Deng, Han; Qi, Xingshun; Peng, Ying; Li, Jing; Li, Hongyu; Zhang, Yongguo; Liu, Xu; Sun, Xiaolin; Guo, Xiaozhong

    2015-12-20

    BACKGROUND Aspartate aminotransferase-to-platelet ratio index (APRI), aspartate aminotransferase-to-alanine aminotransferase ratio (AAR), FIB-4, fibrosis index (FI), and King scores might be alternatives to the use of upper gastrointestinal endoscopy for the diagnosis of esophageal varices (EVs) in liver cirrhosis. This study aimed to evaluate their diagnostic accuracy in predicting the presence and severity of EVs in liver cirrhosis. MATERIAL AND METHODS All patients who were consecutively admitted to our hospital and underwent upper gastrointestinal endoscopy between January 2012 and June 2014 were eligible for this retrospective study. Areas under curve (AUCs) were calculated. Subgroup analyses were performed according to the history of upper gastrointestinal bleeding (UGIB) and splenectomy. RESULTS A total of 650 patients with liver cirrhosis were included, and 81.4% of them had moderate-severe EVs. In the overall analysis, the AUCs of these non-invasive scores for predicting moderate-severe EVs and presence of any EVs were 0.506-0.6 and 0.539-0.612, respectively. In the subgroup analysis of patients without UGIB, their AUCs for predicting moderate-severe varices and presence of any EVs were 0.601-0.664 and 0.596-0.662, respectively. In the subgroup analysis of patients without UGIB or splenectomy, their AUCs for predicting moderate-severe varices and presence of any EVs were 0.627-0.69 and 0.607-0.692, respectively. CONCLUSIONS APRI, AAR, FIB-4, FI, and King scores had modest diagnostic accuracy of EVs in liver cirrhosis. They might not be able to replace the utility of upper gastrointestinal endoscopy for the diagnosis of EVs in liver cirrhosis.

  13. An equation for calculating the volumetric ratios required in a ligation reaction.

    PubMed

    Cranenburgh, R M

    2004-08-01

    The ligation of two DNA fragments to create a new plasmid DNA molecule is a key reaction in molecular biology. Where the fragment lengths and concentrations are known, existing equations allow the desired relative molar ratio to be calculated, but this must then be related to the required volumes. Further calculations are then necessary if the maximum available volume is to consist of DNA solutions. The equation presented here allows the simple calculation of volumes of DNA solutions required to obtain a desired molar insert-to-vector ratio, and these can comprise all of the available volume in a ligation if required, thus maximising the yield of the recombinant plasmid.

  14. Enzymatic Ligation Creates Discrete Multi-Nanoparticle Building Blocks for Self-Assembly

    SciTech Connect

    Claridge, Shelley A.; Mastroianni, Alexander J.; Au, Yeung B.; Liang, Huiyang W.; Micheel, Christine M.; Frechet, Jean M.J.; Alivisatos, A. Paul

    2008-05-27

    Enzymatic ligation of discrete nanoparticle?DNA conjugates creates nanoparticle dimer and trimer structures in which the nanoparticles are linked by single-stranded DNA, rather than double-stranded DNA as in previous experiments. Ligation is verified by agarose gel and small-angle X-ray scattering. This capability is utilized in two ways: first to create a new class of multiparticle building blocks for nanoscale self-assembly; second to develop a system which can amplify a population of discrete nanoparticle assemblies.

  15. Kinetic characterization of on-chip DNA ligation on dendron-coated surfaces with nanoscaled lateral spacings

    NASA Astrophysics Data System (ADS)

    Kim, Eung-Sam; Lee, Namgyu; Park, Joon Won; Choi, Kwan Yong

    2013-10-01

    We analyzed the enzymatic profiles of on-chip DNA ligation as we controlled the lateral spacing of surface-immobilized DNA substrates using dendron molecules with different sizes at the nanoscale. Enzymatic on-chip DNA ligation was performed on the dendron-coated surface within 20 min with no need for post-ligation gel electrophoresis. The enzymatic DNA repair was assessed by the fluorescence intensity at the repaired DNA duplex after thermally dissociating the unligated Cy3-labeled DNA from the DNA duplex, in which the Cy3-labeled DNA was hybridized prior to the on-chip DNA ligation. The rate of the nick-sealing reaction on the 27-acid dendron surface was 3-fold higher than that on the 9-acid dendron surface, suggesting that the wider lateral spacing determined by the larger dendron molecule could facilitate the access of DNA ligase to the nick site. The performance of on-chip DNA ligation was dropped to 10% and 3% when the nick was replaced by one- and two-nucleotide-long gaps, respectively. The 5‧ terminal phosphorylation of DNA strands by polynucleotide kinase and the on-chip DNA cleavage by endonucleases were also quantitatively monitored throughout the on-chip DNA ligation on the dendron-coated surface. A better understanding of the enzymatic kinetics of on-chip DNA ligation will contribute to a more reliable performance of various on-chip DNA ligation-based assays.

  16. Spleen Stiffness Is Superior to Liver Stiffness for Predicting Esophageal Varices in Chronic Liver Disease: A Meta-Analysis

    PubMed Central

    Ma, Xiaowen; Wang, Le; Wu, Hao; Feng, Yuemin; Han, Xibiao; Bu, Haoran; Zhu, Qiang

    2016-01-01

    Background and Aims Liver stiffness (LS) and spleen stiffness (SS) are two most widely accessible non-invasive parameters for predicting esophageal varices (EV), but the reported accuracy of the two predictors have been inconsistent across studies. This meta-analysis aims to evaluate the diagnostic performance of LS and SS measurement for detecting EV in patients with chronic liver disease (CLD), and compare their accuracy. Methods Pubmed/Medline, Embase, Cochrane Library and Ovid were searched for all studies assessing SS and LS simultaneously in EV diagnosis. A total of 16 studies including 1892 patients were included in this meta-analysis, and the pooled statistical parameters were calculated using the bivariate mixed effects models. Results In detection of any EV, for LS measurement, the summary sensitivity was 0.83 (95% confidence interval [CI]: 0.78–0.87), and the specificity was 0.66 (95% CI: 0.60–0.72). While for SS measurement, the pooled sensitivity and specificity was 0.88 (95% CI: 0.83–0.92) and 0.78 (95% CI: 0.73–0.83). The summary receiver operating characteristic (SROC) curve values of LS and SS were 0.81 (95% CI: 0.77–0.84) and 0.88 (95% CI: 0.85–0.91) respectively, and the results had statistical significance (P<0.01). The diagnostic odds ratio (DOR) of SS (25.73) was significantly higher than that of LS (9.54), with the relative DOR value was 2.48 (95%CI: 1.10–5.60), P<0.05. Conclusions Under current techniques, SS is significantly superior to LS for identifying the presence of EV in patients with CLD. SS measurement may help to select patients for endoscopic screening. PMID:27829057

  17. A novel DNA deletion-ligation reaction catalyzed in vitro by a developmentally controlled activity from Tetrahymena cells.

    PubMed

    Robinson, E K; Cohen, P D; Blackburn, E H

    1989-09-08

    Developmentally controlled genomic deletion-ligations occur during ciliate macronuclear differentiation. We have identified a novel activity in Tetrahymena cell-free extracts that efficiently catalyzes a specific set of intramolecular DNA deletion-ligation reactions. When synthetic DNA oligonucleotide substrates were used, all the deletion-ligation products resembled those formed in vivo in that they resulted from deletions between pairs of short direct repeats. The reaction is ATP-dependent, salt-sensitive, and strongly influenced by the oligonucleotide substrate sequence. The deletion-ligation activity has an apparent size of 200-500 kd, no nuclease-sensitive component, and is highly enriched in cells developing new macronuclei. The temperature inactivation profile of the activity parallels the temperature lethality profile specific for Tetrahymena cells developing new macronuclei. We suggest that this deletion-ligation activity carries out the genomic deletions in developing macronuclei in vivo.

  18. Ligation of mouse L4 and L5 spinal nerves produces robust allodynia without major motor function deficit.

    PubMed

    Ye, Gui-Lan; Savelieva, Katerina V; Vogel, Peter; Baker, Kevin B; Mason, Sara; Lanthorn, Thomas H; Rajan, Indrani

    2015-01-01

    Spinal nerve L5/L6 ligation (SNL) in rats has become the standard for mechanistic studies of peripheral neuropathy and screening for novel analgesics. Conventional SNL in our hybrid mice resulted in a wide range of allodynia. Anatomical evaluation indicated that a variable number of lumbar vertebrae existed, resulting in L4/L5 or L5/L6 being ligated. Surprisingly, L4/L5 ligation did not result in ipsilateral hind limb paralysis and produced robust allodynia. Following a recent report that the mouse L4 neural segment is homologous with rat L5 we generated L4, L5 or both L4 and L5 (L4/L5) ligations in C57 mice after establishing a modified set of surgical landmarks. In contrast to rats, L4 ligation in these mice did not result in hind limb paralysis. Robust allodynia was observed in all three ligation groups. Nerve degeneration confirmed that L4 and L5, respectively, are primary contributors to the tibial and sural branches of the sciatic nerve in mice. A larger von Frey sensitive area reflected the wider distribution of Wallerian degeneration in the hindlimb of L4- compared to L5-ligated mice. Ligation of mouse L4 and L5 spinal nerves produces consistent, robust neuropathic pain behaviors and is suitable as a model for investigating mechanisms of neuropathic pain and for testing of novel analgesics. Gabapentin, used as a validation drug in neuropathic pain models and as a reference compound for novel analgesics, significantly reduced allodynia in the mice tested (L4/L5 ligations). Given the ease of surgery, robust allodynia, and larger von Frey sensitive area, we conclude that combined ligation of spinal nerves L4 and L5 optimizes the SNL model in mice.

  19. Impact of splenic artery ligation after major hepatectomy on liver function, regeneration and viability

    PubMed Central

    Carrapita, Jorge; Abrantes, Ana Margarida; Campelos, Sofia; Gonçalves, Ana Cristina; Cardoso, Dulce; Sarmento-Ribeiro, Ana Bela; Rocha, Clara; Santos, Jorge Nunes; Botelho, Maria Filomena; Tralhão, José Guilherme; Farges, Olivier; Barbosa, Jorge Maciel

    2016-01-01

    It was reported that prevention of acute portal overpressure in small-for-size livers by inflow modulation results in a better postoperative outcome. The aim is to investigate the impact of portal blood flow reduction by splenic artery ligation after major hepatectomy in a murine model. Forty-eight rats were subjected to an 85% hepatectomy or 85% hepatectomy and splenic artery ligation. Both groups were evaluated at 24, 48, 72 and 120 post-operative hours: liver function, regeneration and viability. All methods and experiments were carried out in accordance with Coimbra University guidelines. Splenic artery ligation produces viability increase after 24 h, induces a relative decrease in oxidative stress during the first 48 hours, allows antioxidant capacity increment after 24 h, which is reflected in a decrease of half-time normalized liver curve at 48 h and at 72 h and in an increase of mitotic index between 48 h and 72 h. Splenic artery ligation combined with 85% hepatectomy in a murine model, allows portal inflow modulation, promoting an increase in hepatocellular viability and regeneration, without impairing the function, probably by inducing a less marked elevation of oxidative stress at first 48 hours. PMID:27725728

  20. Construct validation of a cost-effective vessel ligation bench-top simulator

    PubMed Central

    Hu, Yinin; Le, Ivy A.; Goodrich, Robyn N.; Edwards, Brandy L.; Gillen, Jacob R.; Smith, Philip W.; Schroen, Anneke T.; Rasmussen, Sara K.

    2014-01-01

    Objective Many bench-top surgical simulators assess laparoscopic proficiency, yet few address core open surgical skills. The purpose of this study is to describe a cost-effective bench-top vessel-ligation simulator and provide construct validation. Design Prospective comparison of blinded proficiency assessments among participants performing a bench-top vessel-ligation simulation task. Evaluations were performed using Objective Structured Assessments of Technical Skills. Setting This study took place at the University of Virginia School of Medicine, a large academic medical institution. Participants Participants included fourth-year medical students participating in a focused surgical elective course (N = 16), post-graduate year (PGY) 2–3 surgery residents (N = 6), and surgical faculty (N = 5). Results Fixed costs of the vessel-ligation simulator totaled $30. Flexible costs of operation were less than $0.20 per attempt. Median task-specific checklist scores among medical students, residents, and faculty were 4.83, 7.33, and 7.67, respectively. Median global rating scores across the three groups were 2.29, 4.43, and 4.76, respectively. Significant proficiency differences were noted between students and residents/faculty for both metrics (p < 0.001). Conclusions A cost-effective bench-top simulator can effectively measure proficiency with basic open surgical techniques such as vessel-ligation. Among junior surgical trainees, this tool can identify learning gaps and improve operative skills in a pre-clinical setting. PMID:25678049

  1. A revised mechanism for the α-ketoacid hydroxylamine amide forming ligations.

    PubMed

    Patil, Mahendra

    2017-01-04

    Computational investigations of the α-ketoacid-hydroxylamine amide-forming (KAHA) ligation of O-unsubstituted (type-I) and O-benzoyl substituted (type-II) hydroxylamine have revealed a distinct mechanistic pathway for the KAHA ligation reactions. Instead of a pathway involving lactone and oxiridine intermediates for the reaction of O-unsubstituted hydroxylamine and ketoacids (type-I KAHA), as had been proposed in the experimental studies, the computational results favor the pathway which involves migration of the hydroxy group (-OH) to the adjacent carbon in one of the key steps. The new pathway for the type I KAHA reaction explains the distribution of the (18)O label in the final product (amide) that is observed in (18)O labeling experiments of type-I ligation reaction. A coherent mechanistic course is also identified for the reaction of O-benzoyl substituted hydroxylamine and ketoacid (type II KAHA) reactions. The proposed pathway for the type-II KAHA ligation reaction proceeds with the retention of an oxygen atom of the keto group of ketoacids rather than hydroxylamine in the final product (amide). These findings are consistent with the results of (18)O labeling experiments performed by Bode and coworkers on the KAHA reactions.

  2. Oxidant and environmental toxicant-induced effects compromise DNA ligation during base excision DNA repair

    PubMed Central

    Çağlayan, Melike; Wilson, Samuel H.

    2015-01-01

    DNA lesions arise from many endogenous and environmental agents, and they promote deleterious events leading to genomic instability and cell death. Base excision repair (BER) is the main DNA repair pathway responsible for repairing single strand breaks, base lesions and abasic sites in mammalian cells. During BER, DNA substrates and repair intermediates are channeled from one step to the next in a sequential fashion so that release of toxic repair intermediates is minimized. This includes handoff of the product of gap-filling DNA synthesis to the DNA ligation step. The conformational differences in DNA polymerase β (pol β) associated with incorrect or oxidized nucleotide (8-oxodGMP) insertion could impact channeling of the repair intermediate to the final step of BER, i.e., DNA ligation by DNA ligase I or the DNA Ligase III/XRCC1 complex. Thus, modified DNA ligase substrates produced by faulty pol β gap-filling could impair coordination between pol β and DNA ligase. Ligation failure is associated with 5'-AMP addition to the repair intermediate and accumulation of strand breaks that could be more toxic than the initial DNA lesions. Here, we provide an overview of the consequences of ligation failure in the last step of BER. We also discuss DNA-end processing mechanisms that could play roles in reversal of impaired BER. PMID:26596511

  3. Oxidant and environmental toxicant-induced effects compromise DNA ligation during base excision DNA repair

    PubMed Central

    çağlayan, Melike; Wilson, Samuel H.

    2015-01-01

    DNA lesions arise from many endogenous and environmental agents, and they promote deleterious events leading to genomic instability and cell death. Base excision repair (BER) is the main DNA repair pathway responsible for repairing single strand breaks, base lesions and abasic sites in mammalian cells. During BER, DNA substrates and repair intermediates are channeled from one step to the next in a sequential fashion so that release of toxic repair intermediates is minimized. This includes handoff of the product of gap-filling DNA synthesis to the DNA ligation step. The conformational differences in DNA polymerase β (pol β) associated with incorrect or oxidized nucleotide (8-oxodGMP) insertion could impact channeling of the repair intermediate to the final step of BER, i.e., DNA ligation by DNA ligase I or the DNA Ligase III/XRCC1 complex. Thus, modified DNA ligase substrates produced by faulty pol β gap-filling could impair coordination between pol β and DNA ligase. Ligation failure is associated with 5′-AMP addition to the repair intermediate and accumulation of strand breaks that could be more toxic than the initial DNA lesions. Here, we provide an overview of the consequences of ligation failure in the last step of BER. We also discuss DNA-end processing mechanisms that could play roles in reversal of impaired BER. PMID:26466358

  4. Histamine receptors expressed in circulating progenitor cells have reciprocal actions in ligation-induced arteriosclerosis.

    PubMed

    Yamada, Sohsuke; Wang, Ke-Yong; Tanimoto, Akihide; Guo, Xin; Nabeshima, Atsunori; Watanabe, Takeshi; Sasaguri, Yasuyuki

    2013-09-01

    Histamine is synthesized as a low-molecular-weight amine from L-histidine by histidine decarboxylase (HDC). Recently, we demonstrated that carotid artery-ligated HDC gene-deficient mice (HDC(-/-)) showed less neointimal formation than wild-type (WT) mice, indicating that histamine participates in the process of arteriosclerosis. However, little is known about the roles of histamine-specific receptors (HHRs) in arteriosclerosis. To define the roles of HHRs in arteriosclerosis, we investigated intimal remodeling in ligated carotid arteries of HHR-deficient mice (H1R(-/-) or H2R(-/-)). Quantitative analysis showed that H1R(-/-) mice had significantly less arteriosclerogenesis, whereas H2R(-/-) mice had more, as compared with WT mice. Bone marrow transplantation from H1R(-/-) or H2R(-/-) to WT mice confirmed the above observation. Furthermore, the increased expression of monocyte chemoattractant protein (MCP-1), platelet-derived growth factor (PDGF), adhesion molecules and liver X receptor (LXR)-related inflammatory signaling factors, including Toll-like receptor (TLR3), interleukin-1 receptor (IL-1R) and tumor necrosis factor receptor (TNF-R), was consistent with the arteriosclerotic phenotype of H2R(-/-) mice. Peripheral progenitor cells in H2R(-/-) mice accelerate ligation-induced arteriosclerosis through their regulation of MCP-1, PDGF, adhesion molecules and LXR-related inflammatory signaling factors. In contrast, peripheral progenitor cells act to suppress arteriosclerosis in H1R(-/-) mice, indicating that HHRs reciprocally regulate inflammation in the ligation-induced arteriosclerosis.

  5. One-Step Ligation on RNA Amplification for the Detection of Point Mutations.

    PubMed

    Zhang, Lei; Wang, Jingjing; Coetzer, Mia; Angione, Stephanie; Kantor, Rami; Tripathi, Anubhav

    2015-11-01

    The detection of point mutations is required in the diagnosis of many human diseases. The conformal specificity of DNA ligases was elegantly used to distinguish single-nucleotide mismatches. However, to detect point mutations in RNA retroviruses, conventional ligase-mediated approaches require the reverse transcription of viral genomes before separate ligation and amplification steps. We developed one-step ligation on RNA amplification (LRA) for the direct detection of RNA point mutations. The process combines the ligase-mediated joining of two oligonucleotides and subsequent hot start amplification into a single-tube reaction. We report that modifications to the structure of the oligonucleotide ligation probes improve the rate of ligation and the specificity of mutation detection on RNA. We applied LRA to the detection of a common, clinically relevant HIV-1 reverse transcriptase drug-resistant point mutation, K103N, and compared it with allele-specific PCR and pyrosequencing. LRA achieved a limit of specific quantitation of 1:100 (1%), and a limit of specific detection for mutant K103N RNA transcripts among excess wild-type strands of 1:10,000 (0.01%). LRA also exhibited good detection threshold of 5 × 10(2) copies/μL K103N RNA transcripts. LRA is a novel point mutation detection method, with potential utilization in HIV drug resistance detection and early diagnostics of genetic disorders associated with other infectious diseases and cancer.

  6. Superficial Dorsal Vein Injury/Thrombosis Presenting as False Penile Fracture Requiring Dorsal Venous Ligation

    PubMed Central

    Rafiei, Arash; Hakky, Tariq S; Martinez, Daniel; Parker, Justin; Carrion, Rafael

    2014-01-01

    Introduction Conditions mimicking penile fracture are extremely rare and have been seldom described. Aim To describe a patient with false penile fracture who presented with superficial dorsal vein injury/thrombosis managed with ligation. Methods A 33-year-old male presented with penile swelling and ecchymosis after intercourse. A penile ultrasound demonstrated a thrombosed superficial dorsal vein but also questionable fracture of the tunica albuginea. As the thrombus was expanding, he was emergently taken to the operating room for exploration and required only dorsal venous ligation. Results Postoperatively, patient's Sexual Health Inventory for Men score was 23, and he had no issues with erections or sexual intercourse. Conclusion Early exploration of patients with suspected penile fracture provides excellent results with maintenance of erectile function. Also, in the setting of dorsal vein thrombosis, ligation preserves the integrity of the penile tissues and avoids unnecessary complications from conservative management. Rafiei A, Hakky TS, Martinez D, Parker J, and Carrion R. Superficial dorsal vein injury/thrombosis presenting as false penile fracture requiring dorsal venous ligation. PMID:25548650

  7. Self-ligating versus Invisalign: analysis of dento-alveolar effects

    PubMed Central

    Pavoni, Chiara; Lione, Roberta; Laganà, Giuseppina; Cozza, Paola

    2011-01-01

    Summary Aim The aim of this study was to evaluate the changes in the transverse dimension and the perimeter of the maxillary arch produced by low friction self-ligating brackets TIME 3 compared to the Invisalign technique. Materials and methods Both the self-ligating sample and the Invisalign group were composed of 20 subjects, evaluated at the beginning (T0) and at the completion of therapy (T1). All subjects presented a Class I malocclusion with mild crowding in a permanent dentition, without craniofacial anomalies, missing teeth or a history of orthodontic treatment. Dento-alveolar measurements were made on the maxillary dental casts at T0 and T1. Significant differences between the treated groups were assessed with Independent Samples t test (p<0.05). Results Statistically significant differences between self-ligating sample and Invisalign group were recorded for CWC, FPWF, FPWL, SPWF, SPWL, and AP measurements. No significant changes were found for CWL, MWF, MWL, and AD values. There was not a statistically significant difference between the treatment durations of the groups: 1.8 years for both patients. These data suggest that Invisalign treatment cannot be somewhat faster than fixed appliances. Moreover the final occlusion might not be as ideal. Conclusions The low fiction self-ligating system produced statistically significant different outcomes in the transverse dento-alveolar width and the perimeter of the maxillary arch during treatment when compared to Invisalign tecnique. PMID:22238719

  8. Branchiostoma floridae has separate healing and sealing enzymes for 5′-phosphate RNA ligation

    PubMed Central

    Englert, Markus; Sheppard, Kelly; Gundllapalli, Sarath; Beier, Hildburg; Söll, Dieter

    2010-01-01

    Animal cells have two tRNA splicing pathways: (i) a 5′-P ligation mechanism, where the 5′-phosphate of the 3′ tRNA half becomes the junction phosphate of the new phosphodiester linkage, and (ii) a 3′-P ligation process, in which the 3′-phosphate of the 5′ tRNA half turns into the junction phosphate. Although both activities are known to exist in animals, in almost three decades of investigation, neither of the two RNA ligases has been identified. Here we describe a gene from the chordate Branchiostoma floridae that encodes an RNA ligase (Bf RNL) with a strict requirement for RNA substrates with a 2′-phosphate terminus for the ligation of RNAs with 5′-phosphate and 3′-hydroxyl ends. Unlike the yeast and plant tRNA ligases involved in tRNA splicing, Bf RNL lacks healing activities and requires the action of a polynucleotide kinase (PNK) and a cyclic phosphodiesterase (CDPase) in trans. The activities of these two enzymes were identified in a single B. floridae protein (Bf PNK/CPDase). The combined activities of Bf RNL and Bf PNK/CPDase are sufficient for the joining of tRNA splicing intermediates in vitro, and for the functional complementation of a tRNA ligase-deficient Saccharomyces cerevisiae strain in vivo. Hence, these two proteins constitute the 5′-P RNA ligation pathway in an animal organism. PMID:20837552

  9. SYNTHESIS OF PROTEINS BY NATIVE CHEMICAL LIGATION USING FMOC-BASED CHEMISTRY

    SciTech Connect

    Camarero, J A; Mitchell, A R

    2005-01-20

    C-terminal peptide {alpha}-thioesters are valuable intermediates in the synthesis/semisynthesis of proteins by native chemical ligation. They are prepared either by solid-phase peptide synthesis (SPPS) or biosynthetically by protein splicing techniques. The present paper reviews the different methods available for the chemical synthesis of peptide {alpha}-thioesters using Fmoc-based SPPS.

  10. Opening and closure forces of sliding mechanisms of different self-ligating brackets

    PubMed Central

    GANDINI, Paola; ORSI, Linda; SFONDRINI, Maria Francesca; SCRIBANTE, Andrea

    2013-01-01

    Self-ligating brackets engage the wire by means of a slide mechanism. Forces that have to be applied to open and close the sliding mechanism of brackets are still unknown. Objective: The aim of this study was to measure and compare the opening and closure forces of different self-ligating brackets. Material and Methods: Three different stainless steel self-ligating brackets (Carriere LX, Ortho Organizers; F1000, Leone; Damon Q, Ormco) were tested. For each different bracket, 20 maxillary right central incisors and 20 mandibular right central incisors were used. Opening and closure forces were measured using an Instron Universal Testing Machine. Statistical analysis was performed and ANOVA and Tukey tests were carried out. Results: Opening forces were registered between 1.1 N and 5.6 N, whereas closure forces were recorded between 1.57 N and 4.87 N. Significant differences were detected among the different brackets and between the two prescriptions tested. Conclusion: The knowledge of different opening and closure forces of self-ligating brackets can help the orthodontist in the clinical management of these devices. PMID:23857652

  11. Comparative clinical evaluation of Kshara Sutra ligation and hemorrhoidectomy in Arsha (hemorrhoids)

    PubMed Central

    Gupta, Meva Lal; Gupta, S. K.; Bhuyan, Chaturbhuja

    2011-01-01

    Arsha (hemorrhoids) is engorgement of the hemorrhoidal venous plexus, characterized by bleeding per rectum, constipation, pain, prolapse and discharge. It is manifested due to improper diet, prolonged standing and faulty habits of defecation causing derangement of tridosha, mainly vata dosha. Vitiated dosha localizes in guda vali, pradhana dhamani and mansdhara kala and vitiates twak, mansa, meda and rakta, resulting in the annavaha sroto dushti. Modern management of arsha needs, mainly, a surgical approach, i.e. hemorrhoidectomy, wherein the result was found to be less satisfactory. In this regard, to determine a solution for satisfactory cure, the kshara sutra ligation method in arsha was studied in comparison with hemarrhoidectomy. Kshara sutra ligation in arsha was employed in 35 patients, and 26 patients were dealt with hemorrhoidectomy. The study revealed a better result of the kshara sutra ligation-treated group in comparison with hemorrhoidectomy. The observations revealed that maximum advantages like minimum hospital stay, no bleeding during or after operation, no post-operative anal stenosis, a low cost-effective and more acceptable to different categories of people, etc. were recorded in the kshara sutra-treated group. Statistically, kshara sutra ligation for arsha was found to be highly significant and effective management. No adverse effects were noted during the follow-up period. PMID:22408307

  12. Oxidant and environmental toxicant-induced effects compromise DNA ligation during base excision DNA repair.

    PubMed

    Çağlayan, Melike; Wilson, Samuel H

    2015-11-01

    DNA lesions arise from many endogenous and environmental agents, and such lesions can promote deleterious events leading to genomic instability and cell death. Base excision repair (BER) is the main DNA repair pathway responsible for repairing single strand breaks, base lesions and abasic sites in mammalian cells. During BER, DNA substrates and repair intermediates are channeled from one step to the next in a sequential fashion so that release of toxic repair intermediates is minimized. This includes handoff of the product of gap-filling DNA synthesis to the DNA ligation step. The conformational differences in DNA polymerase β (pol β) associated with incorrect or oxidized nucleotide (8-oxodGMP) insertion could impact channeling of the repair intermediate to the final step of BER, i.e., DNA ligation by DNA ligase I or the DNA Ligase III/XRCC1 complex. Thus, modified DNA ligase substrates produced by faulty pol β gap-filling could impair coordination between pol β and DNA ligase. Ligation failure is associated with 5'-AMP addition to the repair intermediate and accumulation of strand breaks that could be more toxic than the initial DNA lesions. Here, we provide an overview of the consequences of ligation failure in the last step of BER. We also discuss DNA-end processing mechanisms that could play roles in reversal of impaired BER.

  13. Electronic Configuration of Five-Coordinate High-Spin Pyrazole-Ligated Iron(II) Porphyrinates

    PubMed Central

    Hu, Chuanjiang; Noll, Bruce C.; Schulz, Charles E.; Scheidt, W. Robert

    2010-01-01

    Pyrazole, a neutral nitrogen ligand and an isomer of imidazole, has been used as a fifth ligand to prepare two new species, [Fe(TPP)(Hdmpz)] and [Fe(Tp-OCH3PP)(Hdmpz)] (Hdmpz = 3,5-dimethylpyrazole), the first structurally characterized examples of five-coordinate iron(II) porphyrinates with a nonimidazole neutral ligand. Both complexes are characterized by X-ray crystallography, and structures show common features for five-coordinate iron(II) species, such as an expanded porphinato core, large equatorial Fe–Np bond distances and a significant out-of-plane displacement of the iron(II) atom. The Fe–N(pyrazole) and Fe–Np bond distances are similar to those in imidazole-ligated species. These suggest that the coordination abilities to iron(II) for imidazole and pyrazole are very similar even though pyrazole is less basic than imidazole. Mössbauer studies reveal that [Fe(TPP)(Hdmpz)] has the same behavior as those of imidazole-ligated species, such as negative quadrupole splitting values and relative large asymmetry parameters. Both the structures and Mössbauer spectra suggest pyrazole-ligated five-coordinate iron(II) porphyrinates have the same electronic configuration as imidazole-ligated species. PMID:21047081

  14. Endoscopic ligation of the internal maxillary artery for treatment of intractable posterior epistaxis.

    PubMed

    Pritikin, J B; Caldarelli, D D; Panje, W R

    1998-02-01

    Lack of universal success with both transantral ligation of the internal maxillary artery and percutaneous embolization of the distal branches of the internal maxillary distribution has led to consideration of alternative techniques to control intractable posterior epistaxis. One such technique takes advantage of advances in endoscopic technology and instrumentation, as well as a nearly constant anatomic configuration. The internal maxillary artery divides into terminal branches within the pterygomaxillary fossa, sending branches through the bony maxilla to exit the posterolateral nasal wall in the posterior aspect of the middle meatus. Endoscopic identification and ligation of these terminal branches of the internal maxillary artery (the sphenopalatine and nasopalatine arteries) as they exit the maxilla has been performed on 10 patients with a 100% success rate and no morbidity or mortality associated with the procedure. These results compare favorably to the average reported success rates of 89% for transantral ligation and 94% for percutaneous embolization, and average complication rates of 28% and 27%, respectively. This endonasal procedure has been performed for spontaneous epistaxis as well as postsurgical nasal bleeding with equal success. The ascending scale of treatment previously outlined in the literature may be amended, as a potentially definitive procedure is available, and we believe that this technique is easier to perform, has less associated morbidity, and has equal efficacy in comparison to transantral ligation or percutaneous embolization in the treatment of intractable posterior epistaxis.

  15. Development of a (11)C-labeled tetrazine for rapid tetrazine-trans-cyclooctene ligation.

    PubMed

    Herth, Matthias M; Andersen, Valdemar L; Lehel, Szabolcs; Madsen, Jacob; Knudsen, Gitte M; Kristensen, Jesper L

    2013-05-08

    Tetrazine-trans-cyclooctene ligations are remarkably fast and selective reactions even at low micro-molar concentrations. In bioorthogonal radiochemistry, tools that enable conjugation of radioactive probes to pre-targeted vectors are of great interest. Herein, we describe the successful development of the first (11)C-labelled tetrazine and its reaction with trans-cyclooctenol.

  16. Polyphosphorylation and non-enzymatic template-directed ligation of oligonucleotides

    NASA Technical Reports Server (NTRS)

    Gao, K.; Orgel, L. E.; Bada, J. L. (Principal Investigator)

    2000-01-01

    Oligonucleotide 5'-polyphosphates are formed under potentially prebiotic conditions from oligonucleotide 5'-phosphates and sodium trimetaphosphate. Oligonucleotides activated as polyphosphates undergo template-directed ligation. We believe that these reactions could have produced longer oligonucleotide products from shorter substrates under prebiotic conditions.

  17. Impact of splenic artery ligation after major hepatectomy on liver function, regeneration and viability.

    PubMed

    Carrapita, Jorge; Abrantes, Ana Margarida; Campelos, Sofia; Gonçalves, Ana Cristina; Cardoso, Dulce; Sarmento-Ribeiro, Ana Bela; Rocha, Clara; Santos, Jorge Nunes; Botelho, Maria Filomena; Tralhão, José Guilherme; Farges, Olivier; Barbosa, Jorge Maciel

    2016-10-11

    It was reported that prevention of acute portal overpressure in small-for-size livers by inflow modulation results in a better postoperative outcome. The aim is to investigate the impact of portal blood flow reduction by splenic artery ligation after major hepatectomy in a murine model. Forty-eight rats were subjected to an 85% hepatectomy or 85% hepatectomy and splenic artery ligation. Both groups were evaluated at 24, 48, 72 and 120 post-operative hours: liver function, regeneration and viability. All methods and experiments were carried out in accordance with Coimbra University guidelines. Splenic artery ligation produces viability increase after 24 h, induces a relative decrease in oxidative stress during the first 48 hours, allows antioxidant capacity increment after 24 h, which is reflected in a decrease of half-time normalized liver curve at 48 h and at 72 h and in an increase of mitotic index between 48 h and 72 h. Splenic artery ligation combined with 85% hepatectomy in a murine model, allows portal inflow modulation, promoting an increase in hepatocellular viability and regeneration, without impairing the function, probably by inducing a less marked elevation of oxidative stress at first 48 hours.

  18. Electronic configuration of five-coordinate high-spin pyrazole-ligated iron(II) porphyrinates.

    PubMed

    Hu, Chuanjiang; Noll, Bruce C; Schulz, Charles E; Scheidt, W Robert

    2010-12-06

    Pyrazole, a neutral nitrogen ligand and an isomer of imidazole, has been used as a fifth ligand to prepare two new species, [Fe(TPP)(Hdmpz)] and [Fe(Tp-OCH(3)PP)(Hdmpz)] (Hdmpz = 3,5-dimethylpyrazole), the first structurally characterized examples of five-coordinate iron(II) porphyrinates with a nonimidazole neutral ligand. Both complexes are characterized by X-ray crystallography, and structures show common features for five-coordinate iron(II) species, such as an expanded porphyrinato core, large equatorial Fe-N(p) bond distances, and a significant out-of-plane displacement of the iron(II) atom. The Fe-N(pyrazole) and Fe-N(p) bond distances are similar to those in imidazole-ligated species. These suggest that the coordination abilities to iron(II) for imidazole and pyrazole are very similar even though pyrazole is less basic than imidazole. Mössbauer studies reveal that [Fe(TPP)(Hdmpz)] has the same behavior as those of imidazole-ligated species, such as negative quadrupole splitting values and relative large asymmetry parameters. Both the structures and the Mössbauer spectra suggest pyrazole-ligated five-coordinate iron(II) porphyrinates have the same electronic configuration as imidazole-ligated species.

  19. Single universal primer multiplex ligation-dependent probe amplification with sequencing gel electrophoresis analysis.

    PubMed

    Shang, Ying; Zhu, Pengyu; Xu, Wentao; Guo, Tianxiao; Tian, Wenying; Luo, Yunbo; Huang, Kunlun

    2013-12-15

    In this study, a novel single universal primer multiplex ligation-dependent probe amplification (SUP-MLPA) technique that uses only one universal primer to perform multiplex polymerase chain reaction (PCR) was developed. Two reversely complementary common sequences were designed on the 5' or 3' end of the ligation probes (LPs), which allowed the ligation products to be amplified through only a single universal primer (SUP). SUP-MLPA products were analyzed on sequencing gel electrophoresis with extraordinary resolution. This method avoided the high expenses associated with capillary electrophoresis, which was the commonly used detection instrument. In comparison with conventional multiplex PCR, which suffers from low sensitivity, nonspecificity, and amplification disparity, SUP-MLPA had higher specificity and sensitivity and a low detection limit of 0.1 ng for detecting single crop species when screening the presence of genetically modified crops. We also studied the effect of different lengths of stuffer sequences on the probes for the first time. Through comparing the results of quantitative PCR, the LPs with different stuffer sequences did not affect the ligation efficiency, which further increased the multiplicity of this assay. The improved SUP-MLPA and sequencing gel electrophoresis method will be useful for food and animal feed identification, bacterial detection, and verification of genetic modification status of crops.

  20. Inhibition of lung metastasis of osteosarcoma cell line POS-1 transplanted into mice by thigh ligation.

    PubMed

    Kamijo, Akira; Koshino, Tomihisa; Uesugi, Masaaki; Nitto, Hironori; Saito, Tomoyuki

    2002-12-15

    Using a model with external ligation of the thigh, the effect of ischemia-reperfusion injury on tumor growth and the activity of lung metastasis was investigated in mice inoculated a spontaneous murine osteosarcoma cell line (POS-1) in vivo. POS-1 cell suspension was inoculated into the right hind footpad of 70 mice. Four weeks after inoculation, the ipsilateral thigh was ligated for 3 h in 15 mice and the contralateral thigh in 15 mice. Another ten mice were inoculated with POS-1 without ligating the thigh. The number of metastatic foci on the lung surface 6 weeks after inoculation was 2.29+/-0.98 (mean+/-SE) foci/lungs in mice with ipsilateral ligation and 6.25+/-2.41 in mice with contralateral ligation, which were significantly lower than control (13.40+/-1.42 in mice no ligation) (P<0.01). The number of metastatic foci on the lung surface in mice with intraperitoneal injection of superoxide dismutase (SOD) and catalase was 3.25+/-0.65 (mean+/-SE) foci/lungs in mice with ligation which was significantly greater than that in mice without SOD and catalase injection 1.29+/-0.97 (P=0.04). Cell viability was 9.12+/-4.07% with 100 microM H(2)O(2) in 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. It revealed that at concentrations of 100 microM H(2)O(2) or higher was cytotoxic to POS-1. In cell invasion assay, the number of invading cells with 10 microM H(2)O(2) was 2.80+/-0.53 cells/field, which was significantly lower than control (5.93+/-0.18) (mean+/-SE), indicating that low-dose H(2)O(2) suppressed invasion of POS-1. These results suggested that reperfusion injury had selective cytotoxicity to POS-1 through producing reactive oxygen species. Activated oxygen was considered to inhibit the regional growth and the ability of lung metastasis of POS-1 cells.

  1. The arch of the great saphenous vein: anatomical bases for failures and recurrences after surgical treatment of varices in the pelvic limb. About 54 dissections.

    PubMed

    Ndiaye, Ass; Ndiaye, Abd; Ndoye, J M; Diarra, O; Diop, M; Dia, A; Ndiaye, M; Sow, M L

    2006-03-01

    The arch of the great saphenous vein presents numerous tributaries. Misappreciation of their anatomical variations might cause recurrence after surgical treatment of varices. We dissected 54 inguino-femoral regions of fresh, black African corpses. Our purpose was to study the anatomical variations in the vein confluents of the arch of the great saphenous vein; its positions in relation to the external pudendal artery; establish palpable anatomical markers for its surgical approach. The conventional type in a 'vein star' shape was not the most frequent. Upper or abdominal common vein produced through the merging of superficial veins of the anterior abdominal wall and genital or internal common vein were more frequent. An anterior saphenous vein was found in 23 cases. The external pudendal artery crossed beneath the arch of the great saphenous vein cross in 56% of cases and previously in 44% of cases. On average, the top of the arch of the great saphenous vein was projected out 10.88 cm from the ventral and cranial iliac spine, 3.83 cm from the pubic tubercle and 4.19 cm from the inguinal ligament. In view of our results, variations are real. Knowing and taking them into account are essential to prevent recurrences after surgical treatment of varices of the pelvic limb.

  2. Ligation bias in illumina next-generation DNA libraries: implications for sequencing ancient genomes.

    PubMed

    Seguin-Orlando, Andaine; Schubert, Mikkel; Clary, Joel; Stagegaard, Julia; Alberdi, Maria T; Prado, José Luis; Prieto, Alfredo; Willerslev, Eske; Orlando, Ludovic

    2013-01-01

    Ancient DNA extracts consist of a mixture of endogenous molecules and contaminant DNA templates, often originating from environmental microbes. These two populations of templates exhibit different chemical characteristics, with the former showing depurination and cytosine deamination by-products, resulting from post-mortem DNA damage. Such chemical modifications can interfere with the molecular tools used for building second-generation DNA libraries, and limit our ability to fully characterize the true complexity of ancient DNA extracts. In this study, we first use fresh DNA extracts to demonstrate that library preparation based on adapter ligation at AT-overhangs are biased against DNA templates starting with thymine residues, contrarily to blunt-end adapter ligation. We observe the same bias on fresh DNA extracts sheared on Bioruptor, Covaris and nebulizers. This contradicts previous reports suggesting that this bias could originate from the methods used for shearing DNA. This also suggests that AT-overhang adapter ligation efficiency is affected in a sequence-dependent manner and results in an uneven representation of different genomic contexts. We then show how this bias could affect the base composition of ancient DNA libraries prepared following AT-overhang ligation, mainly by limiting the ability to ligate DNA templates starting with thymines and therefore deaminated cytosines. This results in particular nucleotide misincorporation damage patterns, deviating from the signature generally expected for authenticating ancient sequence data. Consequently, we show that models adequate for estimating post-mortem DNA damage levels must be robust to the molecular tools used for building ancient DNA libraries.

  3. Use of rigid tubal ligation scope: Serendipity in laparoscopic common bile duct exploration

    PubMed Central

    Sahoo, Manash Ranjan; Thimmegowda, Anil Kumar; Behera, Syama Sundar

    2014-01-01

    AIM: To assess the feasibility, safety of rigid tubal ligation scope in laparoscopic common bile duct (CBD) exploration. MATERIALS AND METHODS: Rigid nephroscope was used for laparoscopic CBD exploration until one day we tried the same with the rigid tubal ligation scope, which was passed easily into CBD both proximally and distally visualising the interior of the duct for presence of stone that were removed using endoscopic retrograde cholangiopancreaticography (ERCP) basket. This serendipity led us to use this scope for numerous patients from then on. A total of 62 patients, including male and female, underwent laparoscopic CBD exploration after choledochotomy with rigid tubal ligation scope between March 2007 and December 2012 followed by cholecystectomy. All the patients had both cholelithiasis and choledocholithiasis with minimum duct diameter of 12 mm. A total of 48 patients were given T-tube through choledochotomy and closed, and the remaining 14 patients had primary closure of choledochotomy. RESULTS: There were no intra-operative complications in any of the patients like CBD injury or portal vein injury. Post-operatively graded clamping of T-tube was done and was removed after 15 days in the patients who were given T-tube. None had retained the stone after T-tube cholangiography, which was done before removing the tube. Mean duration of follow up was 6 months. No patients had any complaints during the follow up. CONCLUSION: Laparoscopic CBD exploration is also feasible with rigid tubal ligation scope. With experienced surgeons, CBD injury is very minimal and stone clearance can be achieved in almost all patients. This rigid tubal ligation scope can be an alternative to other rigid and flexible scopes. PMID:24761081

  4. Ligation Bias in Illumina Next-Generation DNA Libraries: Implications for Sequencing Ancient Genomes

    PubMed Central

    Seguin-Orlando, Andaine; Schubert, Mikkel; Clary, Joel; Stagegaard, Julia; Alberdi, Maria T.; Prado, José Luis; Prieto, Alfredo; Willerslev, Eske; Orlando, Ludovic

    2013-01-01

    Ancient DNA extracts consist of a mixture of endogenous molecules and contaminant DNA templates, often originating from environmental microbes. These two populations of templates exhibit different chemical characteristics, with the former showing depurination and cytosine deamination by-products, resulting from post-mortem DNA damage. Such chemical modifications can interfere with the molecular tools used for building second-generation DNA libraries, and limit our ability to fully characterize the true complexity of ancient DNA extracts. In this study, we first use fresh DNA extracts to demonstrate that library preparation based on adapter ligation at AT-overhangs are biased against DNA templates starting with thymine residues, contrarily to blunt-end adapter ligation. We observe the same bias on fresh DNA extracts sheared on Bioruptor, Covaris and nebulizers. This contradicts previous reports suggesting that this bias could originate from the methods used for shearing DNA. This also suggests that AT-overhang adapter ligation efficiency is affected in a sequence-dependent manner and results in an uneven representation of different genomic contexts. We then show how this bias could affect the base composition of ancient DNA libraries prepared following AT-overhang ligation, mainly by limiting the ability to ligate DNA templates starting with thymines and therefore deaminated cytosines. This results in particular nucleotide misincorporation damage patterns, deviating from the signature generally expected for authenticating ancient sequence data. Consequently, we show that models adequate for estimating post-mortem DNA damage levels must be robust to the molecular tools used for building ancient DNA libraries. PMID:24205269

  5. Activation of neurotrophins in lumbar dorsal root probably contributes to neuropathic pain after spinal nerve ligation

    PubMed Central

    Kazemi, Abdolreza; Rahmati, Masoud; Eslami, Rasoul; Sheibani, Vahid

    2017-01-01

    Objective(s): Neurotrophins (NTs) exert various effects on neuronal system. Growing evidence indicates that NTs are involved in the pathophysiology of neuropathic pain. However, the exact role of these proteins in modulating nociceptive signaling requires being defined. Thus, the aim of this study was to evaluate the effects of spinal nerve ligation (SNL) on NTs activation in the lumbar dorsal root. Materials and Methods: Ten male Wistar rats were randomly assigned to two groups: tight ligation of the L5 spinal nerve (SNL: n=5) and Sham (n=5). In order to produce neuropathic pain, the L5 spinal nerve was tightly ligated (SNL). Then, allodynia and hyperalgesia tests were conducted weekly. After 4 weeks, tissue samples were taken from the two groups for laboratory evaluations. Here, Real-Time PCR quantity method was used for measuring NTs gene expression levels. Results: SNL resulted in a significant weight loss in the soleus muscle (P<0.05), mechanical allodynia and thermal hyperalgesia thresholds (respectively, P<0.05; P<0.05). Also, NGF, NT-4, NT-3, TrkA, TrkB and TrkC expression were up-regulated following spinal nerve ligation group (respectively, P=0.025, P=0.013, P=0.001, P=0.002, P<0.001, P=001) (respectively, 4.7, 5.2, 7.5, 5.1, 7.2, 6.2 folds). Conclusion: The present study provides new evidence that neuropathic pain induced by spinal nerve ligation probably activates NTs and Trk receptors expression in DRG. However, further studies are needed to better elucidate the role of NTs in a neuropathic pain. PMID:28133521

  6. Tubal ligation and ovarian cancer risk in a large cohort: Substantial variation by histological type

    PubMed Central

    Green, Jane; Pirie, Kirstin; Reeves, Gillian

    2015-01-01

    Histopathological and molecular studies suggest that different histological subtypes (histotypes) of ovarian cancer have different aetiologies. Few studies have been large enough to explore reliably the effect of tubal ligation (sterilization), which has been associated with a reduced overall risk of ovarian cancer, on different tumour histotypes. In a prospective study of 1.1 million UK women without prior cancer or bilateral oophorectomy, 8,035 ovarian cancers occurred during mean follow‐up of 13.8 years. Using a Cox proportional hazards model, we estimated adjusted relative risks of ovarian cancer associated with tubal ligation. Overall, there was substantial heterogeneity in tumour risk associated with tubal ligation for the four main histotypes, serous, endometrioid, mucinous and clear cell (heterogeneity: p < 0.0001). For serous tumours, the most common histotype (n = 3,515), risks differed significantly between high‐grade (RR: 0.77, 95% CI: 0.67–0.89) and low‐grade tumours (RR: 1.13, 95% CI: 0.89–1.42); heterogeneity: p = 0.007. Relative risks were almost halved for endometrioid (n = 690, RR: 0.54, 95% CI: 0.43–0.69) and clear cell tumours (n = 401, RR: 0.55, 95% CI: 0.39–0.77), but there was no association between tubal ligation and mucinous tumours (n = 836, RR: 0.99, 95% CI: 0.84–1.18). For the main tumour histotypes we found little variation of risk by timing of tubal ligation. The significant differences by tumour histotype are unlikely to be due to confounding and are consistent with hypotheses that high‐grade and low‐grade serous tumours have different origins, and that some endometrioid and clear cell tumours might arise from cells and/or carcinogens travelling through the fallopian tubes. PMID:26378908

  7. A highly efficient catalyst for oxime ligation and hydrazone-oxime exchange suitable for bioconjugation.

    PubMed

    Rashidian, Mohammad; Mahmoodi, Mohammad M; Shah, Rachit; Dozier, Jonathan K; Wagner, Carston R; Distefano, Mark D

    2013-03-20

    Imine-based reactions are useful for a wide range of bioconjugation applications. Although aniline is known to catalyze the oxime ligation reaction under physiological conditions, it suffers from slow reaction kinetics, specifically when a ketone is being used or when hydrazone-oxime exchange is performed. Here, we report on the discovery of a new catalyst that is up to 15 times more efficient than aniline. That catalyst, m-phenylenediamine (mPDA), was initially used to analyze the kinetics of oxime ligation on aldehyde- and ketone-containing small molecules. While mPDA is only modestly more effective than aniline when used in equal concentrations (~2-fold), its much greater aqueous solubility relative to aniline allows it to be used at higher concentrations, resulting in significantly more efficient catalysis. In the context of protein labeling, it was first used to site-specifically label an aldehyde-functionalized protein through oxime ligation, and its kinetics were compared to reaction with aniline. Next, a protein was labeled with an aldehyde-containing substrate in crude cell lysate, captured with hydrazide-functionalized beads and then the kinetics of immobilized protein release via hydrazone-oxime exchange were analyzed. Our results show that mPDA can release and label 15 times more protein than aniline can in 3 h. Then, using the new catalyst, ciliary neurotrophic factor, a protein with therapeutic potential, was successfully labeled with a fluorophore in only 5 min. Finally, a protein containing the unnatural amino acid, p-acetyl phenylalanine, a ketone-containing residue, was prepared and PEGylated efficiently via oxime ligation using mPDA. This new catalyst should have a significant impact on the field of bioconjugation, where oxime ligation and hydrazone-oxime exchange are commonly employed.

  8. Diagnostic Accuracy of APRI, AAR, FIB-4, FI, King, Lok, Forns, and FibroIndex Scores in Predicting the Presence of Esophageal Varices in Liver Cirrhosis: A Systematic Review and Meta-Analysis.

    PubMed

    Deng, Han; Qi, Xingshun; Guo, Xiaozhong

    2015-10-01

    Aspartate aminotransferase-to-platelet ratio (APRI), aspartate aminotransferase-to-alanine aminotransferase ratio (AAR), FIB-4, FI, King, Lok, Forns, and FibroIndex scores may be simple and convenient noninvasive diagnostic tests, because they are based on the regular laboratory tests and demographic data. This study aimed to systematically evaluate their diagnostic accuracy for the prediction of varices in liver cirrhosis.All relevant papers were searched via PubMed, EMBASE, CNKI, and Wanfang databases. The area under the summary receiver operating characteristic curve (AUSROC), sensitivity, specificity, positive and negative likelihood ratio (PLR and NLR), and diagnostic odds ratio (DOR) were calculated.Overall, 12, 4, 5, 0, 0, 4, 3, and 1 paper was identified to explore the diagnostic accuracy of APRI, AAR, FIB-4, FI, King, Lok, Forns, and FibroIndex scores, respectively. The AUSROCs of APRI, AAR, FIB-4, Lok, and Forns scores for the prediction of varices were 0.6774, 0.7275, 0.7755, 0.7885, and 0.7517, respectively; and those for the prediction of large varices were 0.7278, 0.7448, 0.7095, 0.7264, and 0.6530, respectively. The diagnostic threshold effects of FIB-4 and Forns scores for the prediction of varices were statistically significant. The sensitivities/specificities/PLRs/NLRs/DORs of APRI, AAR, and Lok scores for the prediction of varices were 0.60/0.67/1.77/0.58/3.13, 0.64/0.63/1.97/0.54/4.18, and 0.74/0.68/2.34/0.40/5.76, respectively. The sensitivities/specificities/PLRs/NLRs/DORs of APRI, AAR, FIB-4, Lok, and Forns scores for the prediction of large varices were 0.65/0.66/2.15/0.47/4.97, 0.68/0.58/2.07/0.54/3.93, 0.62/0.64/2.02/0.56/3.57, 0.78/0.63/2.09/0.37/5.55, and 0.65/0.61/1.62/0.59/2.75, respectively.APRI, AAR, FIB-4, Lok, and Forns scores had low to moderate diagnostic accuracy in predicting the presence of varices in liver cirrhosis.

  9. Non-histone chromosomal proteins HMG1 and 2 enhance ligation reaction of DNA double-strand breaks.

    PubMed

    Nagaki, S; Yamamoto, M; Yumoto, Y; Shirakawa, H; Yoshida, M; Teraoka, H

    1998-05-08

    DNA ligase IV in a complex with XRCC4 is responsible for DNA end-joining in repair of DNA double-strand breaks (DSB) and V(D)J recombination. We found that non-histone chromosomal high mobility group (HMG) proteins 1 and 2 enhanced the ligation of linearized pUC119 DNA with DNA ligase IV from rat liver nuclear extract. Intra-molecular and inter-molecular ligations of cohesive-ended and blunt-ended DNA were markedly stimulated by HMG1 and 2. Recombinant HMG2-domain A, B, and (A + B) polypeptides were similarly, but non-identically, effective for the stimulation of DSB ligation reaction. Ligation of single-strand breaks (nicks) was only slightly activated by the HMG proteins. The DNA end-binding Ku protein singly or in combination with the catalytic component of DNA-dependent protein kinase (DNA-PK) as the DNA-PK holoenzyme was ineffective for the ligation of linearized pUC119 DNA. Although the stimulatory effect of HMG1 and 2 on ligation of DSB in vitro was not specific to DNA ligase IV, these results suggest that HMG1 and 2 are involved in the final ligation step in DNA end-joining processes of DSB repair and V(D)J recombination.

  10. [Experimental atrophy/hypertrophy complex of the liver after portal and/or biliary ligation in the rat].

    PubMed

    Schweizer, W; Duda, P; Tanner, S; Balsiger, D; Höflin, F; Zimmermann, A; Blumgart, L H

    1992-08-01

    Patients with lobar or segmental, benign or malignant strictures of the biliary tree (with or without impairment of the portal blood flow) show a considerable atrophy of the involved area of the liver with a compensatory hypertrophy/hyperplasia of the remaining non affected liver. To investigate the importance of the biliary and portal obstruction for the development of this process, we used a rat model, with selective biliary and/or portal ligation of the anterior liver lobes (two thirds of the liver mass). Weight measurements, morphometry, functional scintigraphy (Hepatoiodida-scan) and blood enzyme analyses were done immediately postoperatively, at 30 hours and 4, 8 and 28 days after the operation. The major findings were: 1. 28 days after biliary and/or portal ligation there was no difference between the body weight of the four groups, all ligated animals having compensated for an initial greater percentage body-weight loss. 2. Total liver weight remained constant, while atrophy and hypertrophy/hyperplasia occurred although a progressive derangement of liver morphology was observed during that time. 3. A severe atrophy-hypertrophy-complex (AHC) developed after selective portal ligation, which in our experiment did not appear after selective biliary ligation. 4. Morphometrical changes after selective biliary ligation were reversible, whereas in liver lobes with selective portal ligation a progressive parenchymal destruction and involution with subsequent impairment of hepatic function of the concerned lobe was observed.

  11. Glyco-seek: Ultrasensitive Detection of Protein-Specific Glycosylation by Proximity Ligation Polymerase Chain Reaction.

    PubMed

    Robinson, Peter V; Tsai, Cheng-Ting; de Groot, Amber E; McKechnie, Julia L; Bertozzi, Carolyn R

    2016-08-31

    We report a non-destructive biochemical technique, termed "Glyco-seek", for analysis of O-GlcNAcylated proteins. Glyco-seek combines chemoenzymatic labeling, proximity ligation, and quantitative polymerase chain reaction to detect O-GlcNAcylated proteins with ultrahigh sensitivity. Our glycan-specific assay can be paired with traditional proximity ligation assays to simultaneously determine the change in total protein levels. We show that Glyco-seek detects attomoles of glycoproteins of interest from cell lysates, with sensitivity several orders of magnitude higher than that of current techniques. We used the method to directly assay the O-GlcNAcylation status of a low-abundance transcription factor from cell lysates without need for isolation or enrichment.

  12. Determination of the antiulcer properties of sodium cromoglycate in pylorus-ligated albino rats

    PubMed Central

    Srivastava, Vivek; Viswanathaswamy, A.H.M.; Mohan, Govind

    2010-01-01

    Objectives: To study the ulcer protective property of sodium cromoglycate in pylorusligated rats and the biochemical role in ulcer protection by various biochemical tests. Materials and Methods: The ulcer protective effect of sodium cromoglycate was studied using a Pyloric Ligation Model using Wistar albino rats. The antiulcer effect of sodium cromoglycate 40 mg/kg b.w., i.p., was compared with the reference drug ranitidine 27 mg/kg b.w., i.p. The ulcer index was calculated and other biochemical parameters like free acidity, total acidity, pH, mucin, pepsin and volume of gastric juice were determined. Results: Pylorus ligation showed a significant (P < 0.01) reduction in gastric volume, free acidity, total acidity and ulcer index as compared to the control. Conclusion: Sodium cromoglycate has activity equipotent to ranitidine. PMID:20871772

  13. Microscope-assisted endoscopic interlaminar ligation of spinal arteriovenous fistulas: technical note.

    PubMed

    Wang, Chen; Chen, Chien-Min; Shen, Fang; Fang, Xiao-Dong; Ying, Guang-Yu; Ren, Yu-Cheng; Yu, Dan-Feng; Zhu, Liang-Liang; Zhu, Yong-Jian; Zhang, Jian-Min

    2016-09-01

    Spinal dural arteriovenous fistulas (SDAVFs) are the most common type of spinal arteriovenous malformations, and microsurgical ligation is the treatment modality most frequently used for these lesions. Developments in endoscopic techniques have made endoscopy an even less invasive alternative to routine microsurgical approaches in spine surgery, but endoscopic management of SDAVF or other intradural spinal lesions has not been reported to date. The authors describe the use of a microscope-assisted endoscopic interlaminar approach for the ligation of the proximal draining vein of an L-1 SDAVF in a 58-year-old man. A complete cure was confirmed by postoperative angiography. The postoperative course was uneventful, and short-term follow-up showed improvements in the patient's neurological function. The authors conclude that the endoscopic interlaminar approach with microscope assistance is a safe, minimally invasive, innovative technique for the surgical management of SDAVFs in selected patients.

  14. Generation of an affinity column for antibody purification by intein-mediated protein ligation.

    PubMed

    Sun, Luo; Ghosh, Inca; Xu, Ming-Qun

    2003-11-01

    Coupling an antigenic peptide to a solid support is a crucial step in the affinity purification of a peptide-specific antibody. Conventional methods for generating reactive agarose, cellulose or other matrices for peptide conjugation are laborious and can result in a significant amount of chemical waste. In this report, we present a novel method for the facile production of a peptide affinity column by employing intein-mediated protein ligation (IPL) in conjunction with chitin affinity chromatography. A reactive thioester was generated at the C-terminal of the chitin binding domain (CBD) from the chitinase A1 of Bacillus circulans WL-2 by thiol-induced cleavage of the peptide bond between the CBD and a modified intein. Peptide epitopes possessing an N-terminal cysteine were ligated to the chitin bound CBD tag. We demonstrate that the resulting peptide columns permit the highly specific and efficient affinity purification of antibodies from animal sera.

  15. The effect of acute ligation of the rabbit appendix on antioxidant enzymes.

    PubMed

    Turan, C; Kucukaydin, N; Dogan, P; Kontas, O; Bozkurt, A; Kucukaydin, M

    1996-01-01

    The role of oxygen free radicals (OFR) in the pathogenesis of many diseases is known. This experimental study was planned to investigate the role of OFR in acute abdominal inflammation. In this study, 20 adult rabbits were used. They were divided into two groups with 10 rabbits in each. In the study group, blood samples were taken from peripheral and mesenteric veins and then their appendices were ligated; after 24 h, blood samples were taken again and the appendices were resected. The same procedures were carried out in the control group, except for ligation of the appendices. Superoxide dismutase,catalase and glutathione peroxidase (GPX) activities were measured in all blood samples. The activities of catalase and GPX were increased postoperatively in peripheral and mesenteric blood samples in the experimental group. The catalase activity was increased in the control group. These results suggest that OFR increased sufficiently to activate the enzymatic defense system in acute appendicitis.

  16. Atrophy of submandibular gland by the duct ligation and a blockade of SP receptor in rats.

    PubMed

    Hishida, Sumiyo; Ozaki, Noriyuki; Honda, Takashi; Shigetomi, Toshio; Ueda, Minoru; Hibi, Hideharu; Sugiura, Yasuo

    2016-05-01

    To clarify the mechanisms underlying the submandibular gland atrophies associated with ptyalolithiasis, morphological changes were examined in the rat submandibular gland following either surgical intervention of the duct or functional blockade at substance P receptors (SPRs). Progressive acinar atrophy was observed after duct ligation or avulsion of periductal tissues. This suggested that damage to periductal tissue involving nerve fibers might contribute to ligation-associated acinar atrophy. Immunohistochemically labeled-substance P positive nerve fibers (SPFs) coursed in parallel with the main duct and were distributed around the interlobular, striated, granular and intercalated duct, and glandular acini. Strong SPR immunoreactivity was observed in the duct. Injection into the submandibular gland of a SPR antagonist induced marked acinar atrophy. The results revealed that disturbance of SPFs and SPRs might be involved in the atrophy of the submandibular gland associated with ptyalolithiasis.

  17. Atrophy of submandibular gland by the duct ligation and a blockade of SP receptor in rats

    PubMed Central

    Hishida, Sumiyo; Ozaki, Noriyuki; Honda, Takashi; Shigetomi, Toshio; Ueda, Minoru; Hibi, Hideharu; Sugiura, Yasuo

    2016-01-01

    ABSTRACT To clarify the mechanisms underlying the submandibular gland atrophies associated with ptyalolithiasis, morphological changes were examined in the rat submandibular gland following either surgical intervention of the duct or functional blockade at substance P receptors (SPRs). Progressive acinar atrophy was observed after duct ligation or avulsion of periductal tissues. This suggested that damage to periductal tissue involving nerve fibers might contribute to ligation-associated acinar atrophy. Immunohistochemically labeled-substance P positive nerve fibers (SPFs) coursed in parallel with the main duct and were distributed around the interlobular, striated, granular and intercalated duct, and glandular acini. Strong SPR immunoreactivity was observed in the duct. Injection into the submandibular gland of a SPR antagonist induced marked acinar atrophy. The results revealed that disturbance of SPFs and SPRs might be involved in the atrophy of the submandibular gland associated with ptyalolithiasis. PMID:27303108

  18. Identification of cytotoxic agents disrupting synovial sarcoma oncoprotein interactions by proximity ligation assay

    PubMed Central

    Laporte, Aimée N.; Ji, Jennifer X.; Ma, Limin; Nielsen, Torsten O.; Brodin, Bertha A.

    2016-01-01

    Conventional cytotoxic therapies for synovial sarcoma provide limited benefit. Drugs specifically targeting the product of its driver translocation are currently unavailable, in part because the SS18-SSX oncoprotein functions via aberrant interactions within multiprotein complexes. Proximity ligation assay is a recently-developed method that assesses protein-protein interactions in situ. Here we report use of the proximity ligation assay to confirm the oncogenic association of SS18-SSX with its co-factor TLE1 in multiple human synovial sarcoma cell lines and in surgically-excised human tumor tissue. SS18-SSX/TLE1 interactions are disrupted by class I HDAC inhibitors and novel small molecule inhibitors. This assay can be applied in a high-throughput format for drug discovery in fusion-oncoprotein associated cancers where key effector partners are known. PMID:27120803

  19. Laparoscopic Myomectomy with Uterine Artery Ligation: Review Article and Comparative Analysis

    PubMed Central

    Sinha, Rakesh; Sundaram, Meenakshi; Mahajan, Chaitali; Raje, Shweta; Kadam, Pratima; Rao, Gayatri

    2011-01-01

    Uterine leiomyomas are one of the most common benign smooth muscle tumors in women, with a prevalence of 20 to 40% in women over the age of 35 years. Although many women are asymptomatic, problems such as bleeding, pelvic pain, and infertility may necessitate treatment. Laparoscopic myomectomy is one of the treatment options for myomas. The major concern of myomectomy either by open method or by laparoscopy is the bleeding encountered during the procedure. Most studies have aimed at ways of reducing blood loss during myomectomy. There are various ways in which bleeding during laparoscopic myomectomy can be reduced, the most reliable of which is ligation of the uterine vessels bilaterally. In this review we propose to discuss the benefits and possible disadvantages of ligating the uterine arteries bilaterally before performing laparoscopic myomectomy. PMID:22442527

  20. The Association between Endometriosis, Tubal Ligation, Hysterectomy and Epithelial Ovarian Cancer: Meta-Analyses

    PubMed Central

    Wang, Chunpeng; Liang, Zhenzhen; Liu, Xin; Zhang, Qian; Li, Shuang

    2016-01-01

    To investigate the association between endometriosis, tubal ligation, hysterectomy and epithelial ovarian cancer. Relevant published literatures were searched in PubMed, ProQuest, Web of Science and Medline databases during 1995–2016. Heterogeneity was evaluated by I2 statistic. Publication bias was tested by funnel plot and Egger’s test. Odds ratio and 95% CI were used to assess the association strength. The statistical analyses in this study were accomplished by STATA software package. A total of 40,609 cases of epithelial ovarian cancer and 368,452 controls in 38 publications were included. The result suggested that endometriosis was associated with an increased risk of epithelial ovarian cancer (OR = 1.42, 95% CI = 1.28–1.57), tubal ligation was associated with a decreased risk of epithelial ovarian cancer (OR = 0.70, 95% CI = 0.60–0.81), while hysterectomy show no relationship with epithelial ovarian cancer (OR = 0.97, 95% CI = 0.81–1.14). A stratified analysis showed there were associations between endometriosis and the increased risk of epithelial ovarian cancer for studies conducted in USA and Europe. Meanwhile, there were associations between tubal ligation and the decreased risk of epithelial ovarian cancer for studies conducted in USA, Asia, Europe and Australia. The result indicated that endometriosis was a risk factor of epithelial ovarian cancer whereas tubal ligation was a protective risk factor of epithelial ovarian cancer, hysterectomy may have no relationship with epithelial ovarian cancer. PMID:27854255

  1. Comparison between Ultroid and rubber band ligation in treatment of internal hemorrhoids.

    PubMed

    Azizi, Rasoul; Rabani-Karizi, Behzad; Taghipour, Mohammad Ali

    2010-01-01

    Hemorrhoid is one of the most common surgical diseases and different methods are available for its treatment. This study is a comparison between two methods of treatment of internal hemorrhoid, Monopolar low voltage instrument (Ultroid) and Rubber Band Ligation. This method has been carried out prospectively in which 50 patients who were treated with rubber band ligation and 50 patients with Ultroid were compared according to the incidence of complications, post-operative pain and treatment response. According to this study complete success rate with Ultroid was 82% and partial success rate was 10% and no response to treatment was seen in 8%. In Rubber Band method the complete response rate was 94% (P=0.2). With Ultroid, 74% of patient reported no postoperative pain, 24% reported mild and moderate pain and 2% of patients complained of severe pain. With Rubber band ligation, 72% of patients reported no post-operative pain, 26% reported mild and moderate pain and 1% complained of severe pain (P=0.00). Rubber Band ligation and Ultroid are both considered as outpatient procedures for treatment of hemorrhoids. Both methods are mostly used for grade 1, 2 and sometime grade 3 hemorrhoids. In Ultroid method the operator is required to hold the probe for a period of time, and in most cases, the surgeon should spend between 20-25 minutes for the coagulation of three piles. Some surgeons do not have patience for this modality of internal hemorrhoid treatment. In this study we achieved acceptable results comparable with those of other techniques.

  2. [Doppler ultrasound assisted hemorrhoid artery ligation. A new therapy in symptomatic hemorrhoids].

    PubMed

    Arnold, S; Antonietti, E; Rollinger, G; Scheyer, M

    2002-03-01

    In 1995, Morinaga et al. (Japan) reported on a new technique in the treatment of hemorrhoids. We report the results of our first 105 patients thus treated. By a specially designed proctoscope coupled with a Doppler transducer, the hemorrhoidal arteries are looked for and ligated. All stages of hemorrhoid were treated. This method is painless, successful, and has a low rate of complications. It is for outpatients and is an alternative to all other methods in the treatment of hemorrhoids.

  3. EXPRESSED PROTEIN LIGATION. A NEW TOOL FOR THE BIOSYNTHESIS OF CYCLIC POLYPEPTIDES

    SciTech Connect

    Kimura, R; Camarero, J A

    2004-11-11

    The present paper reviews the use of expressed protein ligation for the biosynthesis of backbone cyclic polypeptides. This general method allows the in vivo and in vitro biosynthesis of cyclic polypeptides using recombinant DNA expression techniques. Biosynthetic access to backbone cyclic peptides opens the possibility to generate cell-based combinatorial libraries that can be screened inside living cells for their ability to attenuate or inhibit cellular processes.

  4. Are self-ligating brackets related to less formation of Streptococcus mutans colonies? A systematic review

    PubMed Central

    do Nascimento, Leonard Euler Andrade Gomes; de Souza, Margareth Maria Gomes; Azevedo, Angela Rita Pontes; Maia, Lucianne Cople

    2014-01-01

    Objective To verify, by means of a systematic review, whether the design of brackets (conventional or self-ligating) influences adhesion and formation of Streptococcus mutans colonies. Methods Search strategy: four databases (Cochrane Central Register of Controlled Trials, Ovid ALL EMB Reviews, PubMed and BIREME) were selected to search relevant articles covering the period from January 1965 to December 2012. Selection Criteria: in first consensus by reading the title and abstract. The full text was obtained from publications that met the inclusion criteria. Data collection and analysis: Two reviewers independently extracted data using the keywords: conventional, self-ligating, biofilm, Streptococcus mutans, and systematic review; and independently evaluated the quality of the studies. In case of divergence, the technique of consensus was adopted. Results The search strategy resulted in 1,401 articles. The classification of scientific relevance revealed the high quality of the 6 eligible articles of which outcomes were not unanimous in reporting not only the influence of the design of the brackets (conventional or self-ligating) over adhesion and formation of colonies of Streptococcus mutans, but also that other factors such as the quality of the bracket type, the level of individual oral hygiene, bonding and age may have greater influence. Statistical analysis was not feasible because of the heterogeneous methodological design. Conclusions Within the limitations of this study, it was concluded that there is no evidence for a possible influence of the design of the brackets (conventional or self-ligating) over colony formation and adhesion of Streptococcus mutans. PMID:24713561

  5. Producing peptide arrays for epitope mapping by intein-mediated protein ligation.

    PubMed

    Sun, Luo; Rush, John; Ghosh, Inca; Maunus, Jeremy R; Xu, Ming-Qun

    2004-09-01

    Peptide arrays are increasingly used to define antibody epitopes and substrate specificities of protein kinases. Their use is hampered, however, by ineffective and variable binding efficiency of peptides, which often results in low sensitivity and inconsistent results. To overcome these limitations, we have developed a novel method for making arrays of synthetic peptides on various membranes after ligating the peptide substrates to an intein-generated carrier protein. We have conducted screening for optimal carrier proteins by immunoreactivity and direct assessment of binding using a peptide derivatized at a lysine sidechain with fluorescein, CDPEK(fluorescein)DS. Ligation of a synthetic peptide antigen to a carrier protein, HhaI methylase, resulted in an improved retention of peptides and an increased sensitivity of up to 10(4)-fold in immunoassay- and epitope-scanning experiments. Denaturing the ligation products with 2% sodium dodecyl sulfate (SDS) or an organic solvent (20% methanol) prior to arraying did not significantly affect the immunoreactivity of the HhaI methylase-peptide product. Because the carrier protein dominates the binding of ligation products and contains one peptide reactive site, the amount of peptide arrayed onto the membranes can be effectively normalized. This technique was utilized in the alanine scanning of hemagglutinin (HA) antigen using two monoclonal antibodies, resulting in distinguishing the different antigen epitope profiles. Furthermore, we show that this method can be used to characterize the antibodies that recognize phosphorylated peptides. This novel approach allows for synthetic peptides to be uniformly arrayed onto membranes, compatible with a variety of applications.

  6. Cardioprotective effect of polydatin on ventricular remodeling after myocardial infarction in coronary artery ligation rats.

    PubMed

    Gao, Yan; Gao, Jianping; Chen, Changxun; Wang, Huilin; Guo, Juan; Wu, Rong

    2015-05-01

    The purpose of this study was to explore the effect of polydatin on ventricular remodeling after myocardial infarction in coronary artery ligation rats and to elucidate the underlying mechanisms. A rat model of ventricular remodeling after myocardial infarction was established by left coronary artery ligation. Rats with coronary artery ligation were randomly divided into five groups: control, plus 40 mg/kg captopril, plus 25 mg/kg polydatin, plus 50 mg/kg polydatin, and plus 100 mg/kg polydatin. The sham-operated group was used as a negative control. Rats were administered intragastrically with the corresponding drugs or drinking water for seven weeks. At the end of the treatment, the left ventricular weight index and heart weight index were assessed. The cross-sectional size of cardiomyocytes was measured by staining myocardium tissue with hematoxylin and eosin. Collagen content was counted by Sirius red in aqueous saturated picric acid. The concentrations of angiotensin I, angiotensin II, aldosterone, and endothelin 1 in myocardium or serum were determined by radioimmunoassay. Hydroxyproline and nitric oxide concentrations and glutathione peroxidase and catalase activities in serum were measured by ultraviolet spectrophotometry. Our results showed that seven weeks of polydatin treatment resulted in a significantly reduced left ventricular weight index, heart weight index, serum concentrations of hydroxyproline and aldosterone, an increased concentration of nitric oxide as well as enhanced activities of glutathione peroxidase and catalase. Myocardial angiotensin I, angiotensin II, and endothelin 1 levels were also reduced. The cardiomyocyte cross-sectional area and collagen deposition diminished. This study suggests that polydatin may attenuate ventricular remodeling after myocardial infarction in coronary artery ligation rats through restricting the excessive activation of the renin-angiotensin-aldosterone system and inhibiting peroxidation.

  7. Anesthetic management of an orangutan (Pongo abelii/pygmaeus) undergoing laparoscopic tubal ligation.

    PubMed

    Hendrix, Paula K

    2006-12-01

    An adult hybrid orangutan (Pongo abelii/pygmaeus) was presented to a veterinary teaching hospital for laparoscopic tubal ligation. The orangutan was immobilized with the use of injectable anesthetic agents, then orotracheally intubated. Anesthesia was maintained with the use of isoflurane in oxygen, and positive-pressure ventilation was used to ensure adequate gas exchange. Parameters monitored included arterial blood pressure, ECG, capnometry, and arterial blood gases. Anesthesia was uneventful, and recovery was smooth.

  8. Rapid formation of N-Glycopeptides via Cu(II)-promoted glycosylative ligation.

    PubMed

    Joseph, Ryan; Dyer, Frank Brock; Garner, Philip

    2013-02-15

    Herein is described the chemoselective Cu(II)-HOBt promoted chemical ligation of glycosylamines and peptide thioacids to give N-glycosylated peptides. The method is distinguished from other chemical approaches to peptide N-glycosylation in that (1) it can be employed in the presence of unprotected N-terminal and Lys side chain amines; (2) it is remarkably fast, going to completion in under 30 min; and (3) it produces glycopeptides without attendant aspartimide formation.

  9. Tubal Ligation in Catholic Hospitals: A Qualitative Study of Ob-Gyns’ Experiences

    PubMed Central

    Stulberg, Debra B.; Hoffman, Yael; Dahlquist, Irma Hasham; Freedman, Lori R.

    2014-01-01

    Objective Tubal sterilization remains one of the most commonly requested contraceptive methods in the United States. Catholic hospital policy prohibits all sterilizations, but this ban is not uniformly enforced. We conducted this study to assess obstetrician-gynecologists’ beliefs and experiences with tubal ligation in Catholic hospitals. Study Design We interviewed 31 obstetrician-gynecologists geographically dispersed throughout the U.S. who responded to a national survey and agreed to be contacted for a follow-up interview or who were referred by colleagues from the survey sample. Twenty-seven had experienced working in a Catholic hospital. Interviews were open-ended and guided by a semi-structured instrument. Transcripts were thematically analyzed. Results Obstetrician-gynecologists disagreed with strict prohibition of sterilizations, especially when denying a tubal ligation placed the patient at increased medical risk. Cesarean delivery in Catholic hospitals raised frustration for obstetrician-gynecologists when the hospital prohibited a simultaneous tubal ligation and, thus, sent the patient for an unnecessary subsequent surgery. Obstetrician-gynecologists described some hospitals allowing tubal ligations in limited circumstances, but these workarounds were vulnerable to changes in enforcement. Some obstetrician-gynecologists reported that Catholic policy posed greater barriers for low-income patients and those with insurance restrictions. Conclusion Obstetrician-gynecologists working in Catholic hospitals in this study did not share the Church’s beliefs on sterilization. Research to understand patients’ experiences and knowledge of their sterilization options is warranted in order to promote women’s autonomy and minimize risk of harm. Implications Statement Tubal sterilization, even when medically indicated or in conjunction with cesarean delivery, is severely restricted for women delivering in Catholic hospitals. For women whose only access to

  10. Production of dumbbell probe through hairpin cleavage-ligation and increasing RCA sensitivity and specificity by circle to circle amplification

    PubMed Central

    Wei, Hua; Tang, Suming; Hu, Tianyu; Zhao, Guojie; Guan, Yifu

    2016-01-01

    Dumbbell probe (DP) attracts increasing interests in rolling circle amplification (RCA). A universal DP production method through cleavage-ligation of hairpin was proposed and optimized. The production is characterized by restriction endonuclease (RE)-induced cleavage ends ligation. It has the advantage of phosphorylation-free, splint-free and purification-free. To optimize designing, we found that the position of RE cleavage sequence in the stem and the primer position in the loop affected the formation and amplification of DP obviously. Both sticky and blunt ends cleaved by RE produce DP efficiently. Moreover, we introduced this DP into circle to circle (C2C) RCA based on the same cleavage-ligation principle, and acquired high sensitivity. By combining a two-ligation design and the C2C strategy, specificity for detecting let-7 family members was increased extremely. Furthermore, coreaction of different steps facilitated convenient formation and amplification process of DP. PMID:27385060

  11. Correction of horizontal and vertical discrepancies with a new interactive self-ligating bracket system: the Quick system.

    PubMed

    Cacciafesta, Vittorio; Sfondrini, M Francesca

    2010-01-01

    In the past 10 years, self-ligating brackets have captured the interest of many clinicians and enjoyed increasing popularity. These brackets have been developed to overcome the disadvantages of stainless steel or elastomeric ligatures in terms of ergonomics, efficiency, deformation, discoloration, plaque accumulation, and friction. A self-ligating bracket does not require any type of ligature because it is has a mechanical device that opens and closes the edgewise slot. Secure archwire engagement may be accomplished by a built-in clip. Depending on the interaction between the bracket and archwire, self-ligating brackets can be active and passive. The aim of this article is to describe a new active self-ligating bracket system designed to noticeably reduce the amount of friction that normally originates from archwire-slot interaction, particularly during the correction of horizontal and vertical discrepancies.

  12. Oligonucleotide gap-fill ligation for mutation detection and sequencing in situ.

    PubMed

    Mignardi, Marco; Mezger, Anja; Qian, Xiaoyan; La Fleur, Linnea; Botling, Johan; Larsson, Chatarina; Nilsson, Mats

    2015-12-15

    In clinical diagnostics a great need exists for targeted in situ multiplex nucleic acid analysis as the mutational status can offer guidance for effective treatment. One well-established method uses padlock probes for mutation detection and multiplex expression analysis directly in cells and tissues. Here, we use oligonucleotide gap-fill ligation to further increase specificity and to capture molecular substrates for in situ sequencing. Short oligonucleotides are joined at both ends of a padlock gap probe by two ligation events and are then locally amplified by target-primed rolling circle amplification (RCA) preserving spatial information. We demonstrate the specific detection of the A3243G mutation of mitochondrial DNA and we successfully characterize a single nucleotide variant in the ACTB mRNA in cells by in situ sequencing of RCA products generated by padlock gap-fill ligation. To demonstrate the clinical applicability of our assay, we show specific detection of a point mutation in the EGFR gene in fresh frozen and formalin-fixed, paraffin-embedded (FFPE) lung cancer samples and confirm the detected mutation by in situ sequencing. This approach presents several advantages over conventional padlock probes allowing simpler assay design for multiplexed mutation detection to screen for the presence of mutations in clinically relevant mutational hotspots directly in situ.

  13. Real-Time NMR Studies of Oxyamine Ligations of Reducing Carbohydrates under Equilibrium Conditions.

    PubMed

    Baudendistel, Oliver R; Wieland, Daniel E; Schmidt, Magnus S; Wittmann, Valentin

    2016-11-21

    Ligation reactions at the anomeric center of carbohydrates have gained increasing importance in the field of glycobiology. Oxyamines are frequently used in labeling, immobilization, and bioconjugation of reducing carbohydrates. Herein, we present a systematic investigation of these ligation reactions under aqueous conditions. A series of four unprotected monosaccharides (glucose, N-acetylglucosamine, mannose, and 2-deoxyglucose) and one disaccharide (N,N'-diacetylchitobiose) was reacted with three primary and one secondary oxyamine. We monitored the concentrations of the starting materials and products by (1) H NMR spectroscopy and determined reaction times and equilibrium yields. Our experiments show that the outcome of the ligation reaction is not only dependent on the sugar and oxyamine used but also strongly on the reaction conditions. In the case of glucose, lowering the pH from 6 to 3 led to steadily increasing reaction rates, whereas the yields were decreasing at the same time. Variation of the temperature did not only influence the product ratio in equilibrium but can also have a strong impact on the equilibrium yield. In the case of reactions of a primary oxyamine, increased temperatures led to a higher proportion of acyclic products. Reaction of the secondary oxyamine with glucose unexpectedly led to lower yields at higher temperatures.

  14. Surface ligation-based resonance light scattering analysis of methylated genomic DNA on a microarray platform.

    PubMed

    Ma, Lan; Lei, Zhen; Liu, Xia; Liu, Dianjun; Wang, Zhenxin

    2016-05-10

    DNA methylation is a crucial epigenetic modification and is closely related to tumorigenesis. Herein, a surface ligation-based high throughput method combined with bisulfite treatment is developed for analysis of methylated genomic DNA. In this method, a DNA microarray is employed as a reaction platform, and resonance light scattering (RLS) of nanoparticles is used as the detection principle. The specificity stems from allele-specific ligation of Taq DNA ligase, which is further enhanced by improving the fidelity of Taq DNA ligase in a heterogeneous reaction. Two amplification techniques, rolling circle amplification (RCA) and silver enhancement, are employed after the ligation reaction and a gold nanoparticle (GNP) labeling procedure is used to amplify the signal. As little as 0.01% methylated DNA (i.e. 2 pmol L(-1)) can be distinguished from the cocktail of methylated and unmethylated DNA by the proposed method. More importantly, this method shows good accuracy and sensitivity in profiling the methylation level of genomic DNA of three selected colonic cancer cell lines. This strategy provides a high throughput alternative with reasonable sensitivity and resolution for cancer study and diagnosis.

  15. Evaluation of force released by deflection of orthodontic wires in conventional and self-ligating brackets

    PubMed Central

    Higa, Rodrigo Hitoshi; Semenara, Nayara Thiago; Henriques, José Fernando Castanha; Janson, Guilherme; Sathler, Renata; Fernandes, Thais Maria Freire

    2016-01-01

    ABSTRACT Introduction: The aim of the study was to evaluate deflection forces of rectangular orthodontic wires in conventional (MorelliTM), active (In-Ovation RTM) and passive (Damon 3MXTM) self-ligating brackets. Material and Methods: Two brands of stainless steel and nickel-titanium (NiTi) wires (MorelliTM and GACTM), in addition to OrmcoTM copper-nickel-titanium wires were used. Specimens were assembled in a clinical simulation device especially designed for this study and tested in an Instron universal testing machine. For the testing procedures, an acrylic structure representative of the maxillary right central incisor was lingually moved in activations of 0 to 1 mm, with readings of the force released by deflection in unloading of 0.5, 0.8 and 1 mm at a constant speed of 2 mm/min. Inter-bracket forces with stainless steel, NiTi and CuNiTi were individually compared by two-way ANOVA, followed by Tukey’s tests. Results: Results showed that there were lower forces in conventional brackets, followed by active and passive self-ligating brackets. Within the brands, only for NiTi wires, the MorelliTM brand presented higher forces than GACTM wires. Conclusions: Bracket systems provide different degrees of deflection force, with self-ligating brackets showing the highest forces. PMID:28125144

  16. Coumarin-Induced DNA Ligation, Rearrangement to DNA Interstrand Crosslinks, and Photorelease of Coumarin Moiety.

    PubMed

    Sun, Huabing; Fan, Heli; Eom, Hyeyoung; Peng, Xiaohua

    2016-11-03

    Coumarin moieties react with thymine and cytosine in DNA by photoinduced [2+2] cycloaddition, which allows quantitative DNA interstrand crosslink (ICL) formation. Here, we report the application of coumarin analogues for DNA photoligation and the rearrangement of coumarin-induced ligation to ICL products. Both DNA sequences and the linker units at position 4 of the coumarin moieties affected coumarin-induced DNA photoligation. A flexible linker unit favored DNA ICL formation but led to inefficient photoligation, whereas coumarins without linker units greatly increased DNA photoligation efficiency. DNA photoligation induced by the coumarin moiety was photoswitchable. Ligation products were formed between coumarin and dT or dC upon 350 nm irradiation but reverted to the original single-stranded oligodeoxyribonucleotides (ODNs) upon 254 nm irradiation. Rearrangement of ligated ODNs into ICL products occurred during the switchable (350 nm/254 nm) processes. Additionally, photoinduced cleavage of coumarin 3 occurred with dC-3 cycloadducts upon 254 nm irradiation, which was confirmed by mass spectrometry analysis.

  17. DNA strand transfer catalyzed by vaccinia topoisomerase: ligation of DNAs containing a 3' mononucleotide overhang.

    PubMed

    Cheng, C; Shuman, S

    2000-05-01

    The specificity of vaccinia topoisomerase for transesterification to DNA at the sequence 5'-CCCTT and its versatility in strand transfer have illuminated the recombinogenic properties of type IB topoisomerases and spawned topoisomerase-based strategies for DNA cloning. Here we characterize a pathway of topoisomerase-mediated DNA ligation in which enzyme bound covalently to a CCCTT end with an unpaired +1T nucleotide rapidly and efficiently joins the CCCTT strand to a duplex DNA containing a 3' A overhang. The joining reaction occurs with high efficiency, albeit slowly, to duplex DNAs containing 3' G, T or C overhangs. Strand transfer can be restricted to the correctly paired 3' A overhang by including 0.5 M NaCl in the ligation reaction mixture. The effects of base mismatches and increased ionic strength on the rates of 3' overhang ligation provide a quantitative picture of the relative contributions of +1 T:A base pairing and electrostatic interactions downstream of the scissile phosphate to the productive binding of an unlinked acceptor DNA to the active site. The results clarify the biochemistry underlying topoisomerase-cloning of PCR products with non-templated 3' overhangs.

  18. Ligation of patent ductus arteriosus in very low birthweight premature neonates.

    PubMed Central

    Ghosh, P K; Lubliner, J; Mogilnar, M; Yakirevich, V; Vidne, B A

    1985-01-01

    The results of ligation of a patent ductus arteriosus in 30 premature neonates with a very low birth weight were analysed. The mean gestational age at birth was 27 weeks and the mean weight 811 g. Attempted closure of the ductus with indomethacin in 19 infants failed, though there was temporary closure in nine. Congestive heart failure was present in 29 and respiratory distress in 22 patients. Endotracheal intubation with assisted ventilation was necessary in all cases. The mean age at operation was 13.5 days and ductal ligation was performed in the intensive care unit under local anaesthesia supplemented with pancuronium and pethidine. There were no intraoperative deaths, but five infants died in hospital. There were seven late deaths. Eighteen survivors have been followed for a mean of 26.5 months. Early ligation of a patent ductus arteriosus in premature infants with a very low birth weight improved the cardiorespiratory state. Long term follow up showed good clinical progress in two thirds of the surviving group. PMID:4035621

  19. Psychosocial implications of tubal ligation in a rural health district: A phenomenological study

    PubMed Central

    2011-01-01

    Background Tubal ligation is the most popular family planning method worldwide. While its benefits, such as effectiveness in protecting against pregnancies, minimal need for long-term follow-up and low side-effects profile are well documented, it has many reported complications. However, to date, these complications have not been described by residents in Congo. Therefore, the study aimed at exploring the experience of women who had undergone tubal ligation, focusing on perceptions of physical, psychological and contextual experiences of participants. Methods This qualitative study used a semi-structured questionnaire in a phenomenological paradigm to collect data. Fifteen participants were purposefully selected among sterilized women who had a ligation procedure performed, were aged between 30 and 40 years, and were living within the catchment area of the district hospital. Data were collected by two registered nurses, tape-recorded, and transcribed verbatim. Reading and re-reading cut and paste techniques, and integration were used to establish codes, categories, themes, and description. Results Diverse and sometimes opposite changes in somatic symptoms, psychological symptoms, productivity, ecological relationships, doctor-client relationships, ethical issues, and change of life style were the major problem domains. Conclusions Clients reported conflicting experiences in several areas of their lives after tubal sterilization. Management, including awareness of the particular features of the client, is needed to decrease the likelihood of psychosocial morbidity and/or to select clients in need of sterilization. PMID:22176816

  20. Experiments to optimize enzyme substitution therapy in pancreatic duct-ligated pigs.

    PubMed

    Kammlott, E; Karthoff, J; Stemme, K; Gregory, P; Kamphues, J

    2005-01-01

    Ligation of the pancreatic duct in pigs leads to severe maldigestion and malabsorption of crude nutrients. Supplementation with 24 capsules of Creon (Solvay Pharmaceuticals GmbH, Hannover, Germany) per meal led to an increased digestibility of crude nutrients. With regard to optimization of the treatment of EPI no essential improvements can be achieved by adding omeprazol or lecithin to the diet. In pancreatic duct-ligated pigs the isolated addition of omeprazol led to an increase of the pre-caecal digestibility of crude fat and organic matter. With additional enzyme substitution, the application of omeprazol did not result in an improved fat digestibility. Isolated addition of lecithin to the diet resulted in a reduced total digestibility of crude fat. Offering the diet twice a day and using a higher frequency of enzyme applications (four or six instead of only two applications) had no effects on the digestibilty of crude fat or organic matter. According to the observations in pancreatic duct-ligated pigs, the addition of missing enzymes to the diet led to the best treatment results in EPI. Administration of omeprazol or a higher feeding frequency as well as the application of enzymes in small proportion of the whole meal or dosages given consecutively over the day showed no advantages. Furthermore, the present study suggests that the addition of lecithin cannot be recommended in EPI, when given diets with butter as the predominant fat source as in human dietetics.

  1. FcγRIIa ligation induces platelet hypersensitivity to thrombotic stimuli.

    PubMed

    Berlacher, Mark D; Vieth, Joshua A; Heflin, Brittany C; Gay, Steven R; Antczak, Adam J; Tasma, Brian E; Boardman, Holly J; Singh, Navinderjit; Montel, Angela H; Kahaleh, M Bashar; Worth, Randall G

    2013-01-01

    Platelets are known for their important role in hemostasis, however their significance in other functions, including inflammation and infection, are becoming more apparent. Patients with systemic lupus erythematosus (SLE) are known to have circulating IgG complexes in their blood and are highly susceptible to thrombotic events. Because platelets express a single receptor for IgG, we tested the hypothesis that ligation of this receptor (FcγRIIa) induces platelet hypersensitivity to thrombotic stimuli. Platelets from SLE patients were considerably more sensitive to thrombin compared to healthy volunteers, and this correlated with elevated levels of surface IgG on SLE platelets. To test whether FcγRIIa ligation stimulated thrombin hypersensitivity, platelets from healthy volunteers were incubated with buffer or heat-aggregated IgG, then stimulated with increasing concentrations of thrombin. Interestingly, heat-aggregated IgG-stimulated platelets, but not buffer-treated platelets, were hypersensitive to thrombin, and hypersensitivity was blocked by an anti-FcγRIIa monoclonal antibody (mAb). Thrombin hypersensitivity was not due to changes in thrombin receptor expression (GPIbα or PAR1) but is dependent on activation of shared signaling molecules. These observations suggest that ligation of platelet FcγRIIa by IgG complexes induces a hypersensitive state whereby small changes in thrombotic stimuli may result in platelet activation and subsequent vascular complications such as transient ischemic attacks or stroke.

  2. Safety and effectiveness of total splenic vessel ligations in paediatric patients with splenomegaly

    PubMed Central

    Zhen, Chen; Lishuang, Ma; Jinshan, Zhang; Guoliang, Qiao; Wangchen; Zhen, Zhang; Shuili, Liu; Jun, Zhang; Kaoping, Guan; Long, Li

    2016-01-01

    BACKGROUNDS: Splenomegaly may contribute to hypersplenism and can result in thrombocytopenia. Many approaches are used to treat splenomegaly; however, the current management of splenomegaly has intrinsic limitations or disadvantages. Now, we initiate a new approach, that of total splenic vessel (artery and vein) ligations (TSVLs) in paediatric patients with splenomegaly. The purpose of our study is to evaluate the results obtained with TVSLs procedure for paediatric patients. PATIENTS AND METHODS: Seventeen paediatric patients with splenomegaly were screened for enrolment into this retrospective analysis. PROCEDURE: We identified and dissociated the splenic vessel. Next, we ligated the splenic artery and we used clips to ligate the vein distally and proximally. RESULT: The mean [standard deviation (SD)] splenic infarction rate of a total of 17 patients was 77.5 (5.1)% in 6 months after operation. After TSVL, the mean count of platelet (PLT) and white blood cell (WBC) increased significantly and reached a steady state in the third month. Both the PLT and WBC had a significance higher than pre-TSVL in a 1-year follow-up. CONCLUSION: Based on the evidence, we make cautious conclusions that TSVLs are a safe and effective method in the treatment of paediatric patients with splenomegaly, achieving a satisfactory long-term haematological response and benefit. PMID:27609328

  3. Usefulness of ligation-mediated PCR genotyping in tracking outbreak-associated Mycobacterium tuberculosis strains.

    PubMed

    Mardassi, H; Namouchi, A; Karbouli, A; Khabouchi, N; Haltiti, R; Zarrouk, M; Mhennii, B; Kaabi, S

    2005-01-01

    With the emergence of a multidrug resistant tuberculosis (MDR-TB) outbreak, the availability of a rapid typing method to carry out a nationwide prospective survey for the tracking of newly emerging MDR-TB foci became a priority. For this purpose, we have applied the IS6110 PCR-based genotyping assay, namely, LM-PCR (ligation-mediated PCR). The latter relies on ligation of a synthetic oligonucleotide priming site to a restriction site flanking IS6110. Sequences between the IS element and the restriction site are then amplified using an IS6110 specific outward primer and an oligonucleotide specific to the ligated priming site. Although it was found slightly less discriminative than the standard IS6110 restriction fragment length polymorphism analysis (IS6110 RFLP), LM-PCR allowed for the rapid and prospective identification of new outbreak-related cases within a large pool of circulating M. tuberculosis isolates. In comparison to IS6110 RFLP LM-PCR was found simple enough to justify its implementation in laboratories involved in MDR-TB surveillance at a nationwide scale.

  4. Retrospective study of neonatal ligation during 2002 in the United Kingdom of persistently patent arterial ducts.

    PubMed

    Venkatesh, Vidheya; Lee, Lleona; White, Deborah; Kelsall, Wilf

    2009-08-01

    Our aim was to ascertain the number of neonatal ligations of the patent arterial duct performed in the United Kingdom in 2002, and to determine the survival of the neonates after 30 days. A postal questionnaire was sent to the lead paediatician in every hospital in the United Kingdom possessing a special care or neonatal intensive care unit, requesting information on the number of babies referred for ligation of a persistently patent arterial duct. A separate questionnaire was sent to the paediatric cardiothoracic centres for information on babies who underwent the procedure. Cross-referencing the responses identified neonates who were not reported in the separate questionnaires. Additional information was requested from the central cardiac audit database. The overall response rate was 74%, with 172 forms returned of 234 distributed. From the combined responses, we ascertained that ligation has been performed in 244, with survival at 30 days of 94%. There were problems in identifying some babies because of the incomplete nature of the information received from both referring hospitals and specialist cardiothoracic centres. We would recommend a joint prospective study is conducted by paediatricians and paediatric cardiologists to determine the short and long term outcomes in this population known to be at high risk.

  5. pH-degradable imidazoquinoline-ligated nanogels for lymph node-focused immune activation

    PubMed Central

    Nuhn, Lutz; Vanparijs, Nane; De Beuckelaer, Ans; Lybaert, Lien; Verstraete, Glenn; Deswarte, Kim; Lienenklaus, Stefan; Shukla, Nikunj M.; Salyer, Alex C. D.; Lambrecht, Bart N.; Grooten, Johan; David, Sunil A.; De Koker, Stefaan; De Geest, Bruno G.

    2016-01-01

    Agonists of Toll-like receptors (TLRs) are potent activators of the innate immune system and hold promise as vaccine adjuvant and for anticancer immunotherapy. Unfortunately, in soluble form they readily enter systemic circulation and cause systemic inflammatory toxicity. Here we demonstrate that by covalent ligation of a small-molecule imidazoquinoline-based TLR7/8 agonist to 50-nm-sized degradable polymeric nanogels the potency of the agonist to activate TLR7/8 in in vitro cultured dendritic cells is largely retained. Importantly, imidazoquinoline-ligated nanogels focused the in vivo immune activation on the draining lymph nodes while dramatically reducing systemic inflammation. Mechanistic studies revealed a prevalent passive diffusion of the nanogels to the draining lymph node. Moreover, immunization studies in mice have shown that relative to soluble TLR7/8 agonist, imidazoquinoline-ligated nanogels induce superior antibody and T-cell responses against a tuberculosis antigen. This approach opens possibilities to enhance the therapeutic benefit of small-molecule TLR agonist for a variety of applications. PMID:27382168

  6. The exonuclease activity of DNA polymerase γ is required for ligation during mitochondrial DNA replication

    PubMed Central

    Macao, Bertil; Uhler, Jay P.; Siibak, Triinu; Zhu, Xuefeng; Shi, Yonghong; Sheng, Wenwen; Olsson, Monica; Stewart, James B.; Gustafsson, Claes M.; Falkenberg, Maria

    2015-01-01

    Mitochondrial DNA (mtDNA) polymerase γ (POLγ) harbours a 3′–5′ exonuclease proofreading activity. Here we demonstrate that this activity is required for the creation of ligatable ends during mtDNA replication. Exonuclease-deficient POLγ fails to pause on reaching a downstream 5′-end. Instead, the enzyme continues to polymerize into double-stranded DNA, creating an unligatable 5′-flap. Disease-associated mutations can both increase and decrease exonuclease activity and consequently impair DNA ligation. In mice, inactivation of the exonuclease activity causes an increase in mtDNA mutations and premature ageing phenotypes. These mutator mice also contain high levels of truncated, linear fragments of mtDNA. We demonstrate that the formation of these fragments is due to impaired ligation, causing nicks near the origin of heavy-strand DNA replication. In the subsequent round of replication, the nicks lead to double-strand breaks and linear fragment formation. PMID:26095671

  7. A comparison of two common bile duct ligation methods to establish hepatopulmonary syndrome animal models.

    PubMed

    Yang, Y; Chen, B; Chen, Y; Zu, B; Yi, B; Lu, K

    2015-01-01

    The major drawback of the current common bile duct ligation (CBDL)-induced hepatopulmonary syndrome (HPS) animal model is the extremely high mortality rate that hinders experimental studies. The purpose of this study was to investigate an improved method of CBDL with the goal of developing a simple and reproducible rat HPS model after a single CBDL treatment. Two groups of male Sprague-Dawley rats underwent separate methods of CBDL: (1) the upper common bile duct ligation (UCBDL) group (n = 40), in which the first ligature was made near the junction of the hepatic ducts, and the second ligature was made above the entrance of the pancreatic duct; (2) the middle of the common bile duct ligation (MCBDL) group (n = 40), in which the first ligature was made in the middle of the common bile duct, and the second ligature was made above the entrance of the pancreatic duct. The CBDL-induced HPS rats were evaluated by pulse oximeter, arterial blood analysis, histopathology, and cerebral uptake of intravenous technetium-99m-labeled albumin macroaggregates (which reflects intrapulmonary vascular dilation). The mortality rates of the UCBDL group and the MCBDL group were 42.5% and 77.5%, respectively (P < 0.05). These results suggest that the UCBDL, a single improved procedure, provides a better method compared to the established HPS model, because of the relatively high success rate and the decreased risk of complications.

  8. Encoded Library Synthesis Using Chemical Ligation and the Discovery of sEH Inhibitors from a 334-Million Member Library.

    PubMed

    Litovchick, Alexander; Dumelin, Christoph E; Habeshian, Sevan; Gikunju, Diana; Guié, Marie-Aude; Centrella, Paolo; Zhang, Ying; Sigel, Eric A; Cuozzo, John W; Keefe, Anthony D; Clark, Matthew A

    2015-06-10

    A chemical ligation method for construction of DNA-encoded small-molecule libraries has been developed. Taking advantage of the ability of the Klenow fragment of DNA polymerase to accept templates with triazole linkages in place of phosphodiesters, we have designed a strategy for chemically ligating oligonucleotide tags using cycloaddition chemistry. We have utilized this strategy in the construction and selection of a small molecule library, and successfully identified inhibitors of the enzyme soluble epoxide hydrolase.

  9. Encoded Library Synthesis Using Chemical Ligation and the Discovery of sEH Inhibitors from a 334-Million Member Library

    NASA Astrophysics Data System (ADS)

    Litovchick, Alexander; Dumelin, Christoph E.; Habeshian, Sevan; Gikunju, Diana; Guié, Marie-Aude; Centrella, Paolo; Zhang, Ying; Sigel, Eric A.; Cuozzo, John W.; Keefe, Anthony D.; Clark, Matthew A.

    2015-06-01

    A chemical ligation method for construction of DNA-encoded small-molecule libraries has been developed. Taking advantage of the ability of the Klenow fragment of DNA polymerase to accept templates with triazole linkages in place of phosphodiesters, we have designed a strategy for chemically ligating oligonucleotide tags using cycloaddition chemistry. We have utilized this strategy in the construction and selection of a small molecule library, and successfully identified inhibitors of the enzyme soluble epoxide hydrolase.

  10. Mechanistic insights of rapid liver regeneration after associating liver partition and portal vein ligation for stage hepatectomy

    PubMed Central

    Moris, Demetrios; Vernadakis, Spyridon; Papalampros, Alexandros; Vailas, Michail; Dimitrokallis, Nikolaos; Petrou, Athanasios; Dimitroulis, Dimitrios

    2016-01-01

    AIM To highlight the potential mechanisms of regeneration in the Associating Liver Partition and Portal vein ligation for Stage hepatectomy models (clinical and experimental) that could unlock the myth behind the extraordinary capability of the liver for regeneration, which would help in designing new therapeutic options for the regenerative drive in difficult setup, such as chronic liver diseases. Associating Liver Partition and Portal vein ligation for Stage hepatectomy has been recently advocated to induce rapid future liver remnant hypertrophy that significantly shortens the time for the second stage hepatectomy. The introduction of Associating Liver Partition and Portal vein ligation for Stage hepatectomy in the surgical armamentarium of therapeutic tools for liver surgeons represented a real breakthrough in the history of liver surgery. METHODS A comprehensive literature review of Associating Liver Partition and Portal vein ligation for Stage hepatectomy and its utility in liver regeneration is performed. RESULTS Liver regeneration after Associating Liver Partition and Portal vein ligation for Stage hepatectomy is a combination of portal flow changes and parenchymal transection that generate a systematic response inducing hepatocyte proliferation and remodeling. CONCLUSION Associating Liver Partition and Portal vein ligation for Stage hepatectomy represents a real breakthrough in the history of liver surgery because it offers rapid liver regeneration potential that facilitate resection of liver tumors that were previously though unresectable. The jury is still out though in terms of safety, efficacy and oncological outcomes. As far as Associating Liver Partition and Portal vein ligation for Stage hepatectomy -induced liver regeneration is concerned, further research on the field should focus on the role of non-parenchymal cells in liver regeneration as well as on the effect of Associating Liver Partition and Portal vein ligation for Stage hepatectomy in liver

  11. Ultrasensitive detection of DNA and RNA based on enzyme-free click chemical ligation chain reaction on dispersed gold nanoparticles.

    PubMed

    Kato, Daiki; Oishi, Motoi

    2014-10-28

    An ultrasensitive colorimetric DNA and RNA assay using a combination of enzyme-free click chemical ligation chain reaction (CCLCR) on dispersed gold nanoparticles (GNPs) and a magnetic separation process has been developed. The click chemical ligation between an azide-containing probe DNA-modified GNP and a dibenzocyclooctyne-containing probe biotinyl DNA occurred through hybridization with target DNA (RNA) to form the biotinyl-ligated GNPs (ligated products). Eventually, both the biotinyl-ligated GNPs and target DNA (RNA) were amplified exponentially using thermal cycling. After separation of the biotinyl-ligated GNPs using streptavidin-modified magnetic beads, the change in intensity of the surface plasmon band at 525 nm in the supernatants was observed by UV/vis measurement and was also evident visually. The CCLCR assay provides ultrasensitive detection (50 zM: several copies) of target DNA that is comparable to PCR-based approaches. Note that target RNA could also be detected with similar sensitivity without the need for reverse transcription to the corresponding cDNA. The amplification efficiency of the CCLCR assay was as high as 82% due to the pseudohomogeneous reaction behavior of CCLCR on dispersed GNPs. In addition, the CCLCR assay was able to discriminate differences in single-base mismatches and to specifically detect target DNA and target RNA from the cell lysate.

  12. Universal strategies for the DNA-encoding of libraries of small molecules using the chemical ligation of oligonucleotide tags.

    PubMed

    Litovchick, Alexander; Clark, Matthew A; Keefe, Anthony D

    2014-01-01

    The affinity-mediated selection of large libraries of DNA-encoded small molecules is increasingly being used to initiate drug discovery programs. We present universal methods for the encoding of such libraries using the chemical ligation of oligonucleotides. These methods may be used to record the chemical history of individual library members during combinatorial synthesis processes. We demonstrate three different chemical ligation methods as examples of information recording processes (writing) for such libraries and two different cDNA-generation methods as examples of information retrieval processes (reading) from such libraries. The example writing methods include uncatalyzed and Cu(I)-catalyzed alkyne-azide cycloadditions and a novel photochemical thymidine-psoralen cycloaddition. The first reading method "relay primer-dependent bypass" utilizes a relay primer that hybridizes across a chemical ligation junction embedded in a fixed-sequence and is extended at its 3'-terminus prior to ligation to adjacent oligonucleotides. The second reading method "repeat-dependent bypass" utilizes chemical ligation junctions that are flanked by repeated sequences. The upstream repeat is copied prior to a rearrangement event during which the 3'-terminus of the cDNA hybridizes to the downstream repeat and polymerization continues. In principle these reading methods may be used with any ligation chemistry and offer universal strategies for the encoding (writing) and interpretation (reading) of DNA-encoded chemical libraries.

  13. Universal strategies for the DNA-encoding of libraries of small molecules using the chemical ligation of oligonucleotide tags

    PubMed Central

    Litovchick, Alexander; Clark, Matthew A; Keefe, Anthony D

    2014-01-01

    The affinity-mediated selection of large libraries of DNA-encoded small molecules is increasingly being used to initiate drug discovery programs. We present universal methods for the encoding of such libraries using the chemical ligation of oligonucleotides. These methods may be used to record the chemical history of individual library members during combinatorial synthesis processes. We demonstrate three different chemical ligation methods as examples of information recording processes (writing) for such libraries and two different cDNA-generation methods as examples of information retrieval processes (reading) from such libraries. The example writing methods include uncatalyzed and Cu(I)-catalyzed alkyne-azide cycloadditions and a novel photochemical thymidine-psoralen cycloaddition. The first reading method “relay primer-dependent bypass” utilizes a relay primer that hybridizes across a chemical ligation junction embedded in a fixed-sequence and is extended at its 3′-terminus prior to ligation to adjacent oligonucleotides. The second reading method “repeat-dependent bypass” utilizes chemical ligation junctions that are flanked by repeated sequences. The upstream repeat is copied prior to a rearrangement event during which the 3′-terminus of the cDNA hybridizes to the downstream repeat and polymerization continues. In principle these reading methods may be used with any ligation chemistry and offer universal strategies for the encoding (writing) and interpretation (reading) of DNA-encoded chemical libraries. PMID:25483841

  14. Nonenzymatic, template-directed ligation of oligoribonucleotides is highly regioselective for the formation of 3'-5' phosphodiester bonds

    NASA Technical Reports Server (NTRS)

    Rohatgi, R.; Bartel, D. P.; Szostak, J. W.

    1996-01-01

    We have found that nonenzymatic, template-directed ligation reactions of oligoribonucleotides display high selectivity for the formation of 3'-5' rather than 2'-5' phosphodiester bonds. Formation of the 3'-5'-linked product is favored regardless of the metal ion catalyst or the leaving group, and for several different ligation junction sequences. The degree of selectivity depends on the leaving group: the ratio of 3'-5'- to 2'-5'-linked products was 10-15:1 when the 5'-phosphate was activated as the imidazolide, and 60-80:1 when the 5'-phosphate was activated by the formation of a 5'-triphosphate. Comparison of oligonucleotide ligation reactions with previously characterized single nucleotide primer extension reactions suggests that the strong preference for 3'-5'-linkages in oligonucleotide ligation is primarily due to occurence of ligation within the context of an extended Watston-Crick duplex. The ability of RNA to correctly self-assemble by template-directed ligation is an intrinsic consequence of its chemical structure and need not be imposed by an external catalyst (i.e., an enzyme polymerase); RNA therefore provides a reasonable structural basis for a self-replicating system in a prebiological world.

  15. Early clinical experience of the safety and efficacy of EndoClot in the management of non-variceal upper gastrointestinal bleeding

    PubMed Central

    Beg, Sabina; Al-Bakir, Ibrahim; Bhuva, Meha; Patel, Jay; Fullard, Mark; Leahy, Anthony

    2015-01-01

    Background and study aims: EndoClot is a novel topical hemostatic powder approved for use in non-variceal upper gastrointestinal bleeding. This study examines its impact as rescue therapy in the management of gastrointestinal bleeding for which standard endoscopic therapy failed to achieve hemostasis. Methods: This observational study covered a 24-month period. Data were collated from patients treated with EndoClot for comparison with a cohort of patients managed with standard endoscopic therapy. End points of this study included immediate hemostasis, 30-day rebleed rate, 30-day mortality rate, and adverse events. Results: Between April 1, 2012, and March 31, 2014, gastroscopic procedures were performed in 1009 patients, of whom 173 required endoscopic therapy. EndoClot was used in 21 patients, with immediate hemostasis achieved in all cases, a 30-day rebleed rate of 4.8 % (95 % confidence interval [95 %CI] – 4.34 % to 3.94 %), and a 30-day mortality rate of 19.0 % (95 %CI 2.29 % – 35.91 %). Despite higher risk bleeds in this cohort of patients, Fisher's exact test demonstrated no significant difference between their 30-day mortality rate (P = 0.51) and rebleed rate (P = 0.31) and those of the patients treated with standard endoscopic hemostatic techniques. Conclusions: This study demonstrates that EndoClot can be used both safely and effectively in the management of non-variceal upper gastrointestinal bleeding. PMID:26716120

  16. Cost analysis for the prevention of variceal rebleeding: a comparison between transjugular intrahepatic portosystemic shunt and endoscopic sclerotherapy in a selected group of Italian cirrhotic patients.

    PubMed

    Meddi, P; Merli, M; Lionetti, R; De Santis, A; Valeriano, V; Masini, A; Rossi, P; Salvatori, F; Salerno, F; de Franchis, R; Capocaccia, L; Riggio, O

    1999-04-01

    The aim of the present study was to compare the cumulative cost of the first 18-month period in a selected group of Italian cirrhotic patients treated with transjugular intrahepatic portosystemic shunt (TIPS) versus endoscopic sclerotherapy (ES) to prevent variceal rebleeding. Thirty-eight patients enrolled in a controlled trial were considered (18 TIPS and 20 sclerotherapy). The number of days spent in the hospital for the initial treatment and during the follow-up period were defined as the costs of hospitalization. ES sessions, TIPS procedures, angioplasty or addition of a second stent to maintain the shunt patency, were defined as the costs of therapeutic procedures. The two groups were comparable for age, sex, and Child-Pugh score. During the observation period 4 patients died in the TIPS group, and 2 died and 1 was transplanted in the sclerotherapy group. The rebleeding rate was significantly higher in the sclerotherapy group. Despite this, the number of days spent in the hospital was similar in the two groups. This was because of a higher number of hospital admissions for the treatment of hepatic encephalopathy and shunt insufficiency in the TIPS group. The therapeutic procedures were more expensive for TIPS. Consequently, the cumulative cost was higher for patients treated with TIPS than for those treated with sclerotherapy. The extra cost was because of the initial higher cost of the procedure and the difference was still maintained at the end of the 18-month follow-up. When the cumulative costs were expressed per month free of rebleeding, the disadvantage of TIPS disappeared. In conclusion, a program of prevention of variceal rebleeding with TIPS, despite the longer interval free of rebleeding, is not a cost-saving strategy in comparison with sclerotherapy.

  17. A totally laparoscopic associating liver partition and portal vein ligation for staged hepatectomy assisted with radiofrequency (radiofrequency assisted liver partition with portal vein ligation) for staged liver resection

    PubMed Central

    Hakim, David N.; Gall, Tamara M. H.; Fajardo, Ana; Pencavel, Tim D.; Fan, Ruifang; Sodergren, Mikael H.

    2016-01-01

    In order to induce liver hypertrophy to enable liver resection in patients with a small future liver remnant (FLR), various methods have been proposed in addition to portal vein embolisation (PVE). Most recently, the associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) technique has gained significant international interest. This technique is limited by the high morbidity associated with an in situ liver splitting and the patient undergoing two open operations. We present the case of a variant ALPPS technique performed entirely laparoscopically with no major morbidity or mortality. An increased liver volume of 57.9% was seen after 14 days. This technique is feasible to perform and compares favourably to other ALPPS methods whilst gaining the advantages of laparoscopic surgery. PMID:27500150

  18. Partial ligation-induced carotid artery occlusion induces leukocyte recruitment and lipid accumulation--a shear stress model of atherosclerosis.

    PubMed

    Merino, Hilda; Parthasarathy, Sampath; Singla, Dinender K

    2013-01-01

    Recent studies suggest that disturbed blood flow-induced shear stress can induce atherosclerosis (ATH) in humans and animals without a high fat diet. Therefore, we hypothesize that partial ligation of the left carotid artery can generate disturbed blood flow and shear stress and would lead to ATH in a predisposed genetic model of Apo E(-/-) mice. The partial left carotid artery model was generated by ligating three out of four branches of the left carotid artery compared with controls which experienced similar surgery conditions but no ligation. Animals were sacrificed 2 weeks post-ligation and examined for plaque formation, infiltration of leukocytes, pro-inflammatory immune response, and blood flow velocity. Our findings suggest a significant (p < 0.05) increase in plaque formation and lipid deposition in the partial ligated animals compared with controls, confirmed with hematoxylin and eosin and oil red O staining. Furthermore, there was a significant (p < 0.05) increase in the number of M1 macrophages and release of pro-inflammatory cytokines, IL-6 and TNFα, as compared with the control. Moreover, partial ligated carotid arteries demonstrated disturbed blood flow as their systolic velocity was significantly reduced. In conclusion, our data suggest that partial ligation of the left carotid artery induces disturbed flow and shear stress in the predisposed genetic model of Apo E(-/-) mice and leads to significantly developed ATH. Similarities to clinical patients who develop ATH independent of a high fat diet show that this could be a potential animal model to examine various parameters in ATH.

  19. Evidence of liquid crystal-assisted abiotic ligation of nucleic acids.

    PubMed

    Fraccia, Tommaso P; Zanchetta, Giuliano; Rimoldi, Valeria; Clark, Noel A; Bellini, Tommaso

    2015-06-01

    The emergence of early life must have been marked by the appearance in the prebiotic era of complex molecular structures and systems, motivating the investigation of conditions that could not only facilitate appropriate chemical synthesis, but also provide the mechanisms of molecular selection and structural templating necessary to pilot the complexification toward specific molecular patterns. We recently proposed and demonstrated that these functions could be afforded by the spontaneous ordering of ultrashort nucleic acids oligomers into Liquid Crystal (LC) phases. In such supramolecular assemblies, duplex-forming oligomers are held in average end-to-end contact to form chemically discontinuous but physically continuous double helices. Using blunt ended duplexes, we found that LC formation could both provide molecular selection mechanisms and boost inter-oligomer ligation. This paper provides an essential extension to this notion by investigating the catalytic effects of LC ordering in duplexes with mutually interacting overhangs. Specifically, we studied the influence of LC ordering of 5'-hydroxy-3'-phosphate partially self-complementary DNA 14mers with 3'-CG sticky-ends, on the efficiency of non-enzymatic ligation reaction induced by water-soluble carbodiimide EDC as condensing agent. We investigated the ligation products in mixtures of DNA with poly-ethylene glycol (PEG) at three PEG concentrations at which the system phase separates creating DNA-rich droplets that organize into isotropic, nematic LC and columnar LC phases. We observe remarkable LC-enhanced chain lengthening, and we demonstrate that such lengthening effectively promotes and stabilizes LC domains, providing the kernel of a positive feedback cycle by which LC ordering promotes elongation, in turn stabilizing the LC ordering.

  20. Ligation under vision of haemorrhoidal cushions for therapy of bleeding haemorrhoids.

    PubMed

    Bronstein, M; Issa, N; Gutman, M; Neufeld, D

    2008-06-01

    Ligation under vision (LUV) is a simple method for the surgical treatment of haemorrhoids. In this study, we evaluated the results of our initial experience with the procedure in terms of postoperative pain, patients' final satisfaction and complications. We reviewed a group of patients who had undergone suture ligation of symptomatic haemorrhoids of grade II and III. This was performed with the haemorrhoids under direct vision and without the use of any ancillary instrumentation such as a Doppler sensor. All interventions were performed in the day-care surgical unit using general or regional anaesthesia. Surgical outcome and degree of postoperative pain were determined from outpatient clinic follow-up and individual phone interviews. A total of 32 patients (19 men and 13 women) with a mean age of 59 years had undergone LUV. There were 23 patients (72%) with grade II and 9 patients (28%) with grade III haemorrhoids. The indication for the surgery was bleeding in 19 patients (59%), prolapse in 6 (19%) and both in 7 (22%). A previous rubber band ligation had been carried out in 17 patients (53%). On average, the surgery took 22 min. All patients were discharged on the same day. Four %patients (12%) suffered only mild postoperative pain, 14 (44%) suffered from moderate pain and another 14 (44%) had severe pain. At follow-up (median 21 months, range 9-33 months), 28 %patients (87.5%) were completely asymptomatic at the time of the phone interview. The final result was assessed as excellent by 19 patients (60%), successful by 10 (31%), and unsuccessful by 3 (9%). All patients had complete functional recovery and there were no major surgical complications. Our data show that LUV of symptomatic haemorrhoids is a simple and safe procedure. It can be performed as effective isolated surgery for symptomatic haemorrhoids and as an additional procedure in the treatment of complex perianal pathology.

  1. [Post-translational ligation and function of dual-vector transferred split CFTR gene].

    PubMed

    Zhu, Fu-Xiang; Liu, Ze-Long; Qu, Hui-Ge; Chi, Xiao-Yan

    2010-01-01

    The mutation of cystic fibrosis transmembrane conductance regulator (CFTR) gene leads to an autosomal recessive genetic disorder cystic fibrosis (CF). The gene therapy for CF using adeno-associated virus (AAV) vectors delivering CFTR gene is restricted by the contents limitation of AAV vectors. In this study the split CFTR genes severed at its regulatory domain were delivered by a dual-vector system with an intein-mediated protein trans-splicing as a technique to investigate the post-translational ligation of CFTR half proteins and its function as a chloride ion channel. A pair of eukaryotic expression vectors was constructed by breaking the human CFTR cDNA before Ser712 codon and fusing with Ssp DnaB intein coding sequences. After co-transfection into baby hamster kidney (BHK) cells followed by transient expression, patch clamps were carried out to record the chloride current of whole-cell and the activity of a single channel, and the ligation of two halves of CFTR was observed by Western blotting. The results showed that the intein-fused half genes co-transfected cells displayed a high whole cell chloride current and activity of a single channel indicating the functional recovery of chloride channel, and an intact CFTR protein band was figured out by CFTR-specific antibodies indicating that intein can efficiently ligate the separately expressed half CFTR proteins. The data demonstrated that protein splicing strategy could be used as a strategy in delivering CFTR gene by two vectors, encouraging our ongoing research program on dual AAV vector system based gene transfer in gene therapy for cystic fibrosis.

  2. SADI-S WITH RIGHT GASTRIC ARTERY LIGATION: TECHNICAL SYSTEMATIZATION AND EARLY RESULTS

    PubMed Central

    GEBELLI, Jordi Pujol; de GORDEJUELA, Amador Garcia Ruiz; RAMOS, Almino Cardoso; NORA, Mario; PEREIRA, Ana Marta; CAMPOS, Josemberg Marins; RAMOS, Manoela Galvão; BASTOS, Eduardo Lemos de Souza; MARCHESINI, João Batista

    2016-01-01

    ABSTRACT Background: Bariatric surgery is performed all over the world with close to 500.000 procedures per year. The most performed techniques are Roux-en-Y gastric bypass and sleeve gastrectomy. Despite this data, the most effective procedure, biliopancreatic diversion with or without duodenal switch, represents only no more than 1.5% of the procedures. Technical complexity, morbidity, mortality, and severe nutritional adverse effects related to the procedure are the main fears that prevent most universal acceptance. Aim: To explain the technical aspects and the benefits of the SADI-S with right gastric artery ligation as an effective simplification from the original duodenal switch. Methods: Were included all patients undergoing this procedure from the November 2014 to May 2016, describing and analysing aspects of this technique, the systematization and early complications associated with the procedure. Results: A series of 67 patients were operated; 46 were women (68.7%); mean age of the group was 44 years old (33-56); and an average BMI of 53.5 kg/m2 (50-63.5). Surgical time was 115 min (80-180). A total of five patients (7.5%) had any complication and two (2.9%) had to be reoperated. There were two patients with leak, one at the duodenal stump and other at the esophagogastric angle. There was no mortality. Patients stayed at the hospital a median of 2.5 days (1-25). Conclusions: SADI-S with right gastric artery ligation is a safe procedure with few preliminary complications. The technical variations introduced to the classical duodenal switch are reproducible and may allow this procedure to be more popular. All the complications in this series were not related to the ligation of the right gastric artery. PMID:27683784

  3. Optimal Duration of Coronary Ligation and Reperfusion for Reperfusion Injury Study in a Rat Model

    PubMed Central

    Chang, Shih-Tai; Chu, Chi-Ming; Yang, Teng-Yao; Hung, Li-Man; Pan, Kuo-Li; Cherng, Wen-Jin

    2016-01-01

    Background Reperfusion injury (RI) has an important impact on the clinical prognosis for patients with acute myocardial injury who had their coronary blood flow reestablished. However, no studies to date have investigated the timeframe of coronary occlusion and reperfusion effects on RI. Methods A total of 100 rats were divided into 4 groups based on the coronary ligation period: 30, 60, 120, and 180 min, and each group was further divided into 5 subgroups with different reperfusion periods: 0, 30, 60, 120, and 180 min. R0 was the baseline of each subgroup. All animals received the same protocols for designed ligation and reperfusion periods. Evans blue and 2,3,5-triphenyltetrazolium chloride were used to distinguish different myocardial injury areas: area at risk (AAR) and myocardial necrosis. The differences of the ratios of the necrotic area to AAR between each subgroup and baseline were further averaged to calculate an overall value of each heart. Results The relative RI percentages showed significant differences (0.8 ± 2.3%, 4.9 ± 3.3%, 10.8 ± 3.1%, and 20.3 ± 3.6% respectively, p < 0.001) at different time points of reperfusion but not at different time points of ligation (p = 0.593). The effects of different time courses in RI showed that the L120R180 group (43.4 ± 2.3%) had the highest RI difference with the baseline group. Conclusions Maximal RI occurred at the timeframe of L120R180 in our animal model. This result may be utilized to assess the substantial benefits of RI therapies in an experimental rat model setting. PMID:27471363

  4. Evidence of Liquid Crystal-Assisted Abiotic Ligation of Nucleic Acids

    NASA Astrophysics Data System (ADS)

    Fraccia, Tommaso P.; Zanchetta, Giuliano; Rimoldi, Valeria; Clark, Noel A.; Bellini, Tommaso

    2015-06-01

    The emergence of early life must have been marked by the appearance in the prebiotic era of complex molecular structures and systems, motivating the investigation of conditions that could not only facilitate appropriate chemical synthesis, but also provide the mechanisms of molecular selection and structural templating necessary to pilot the complexification toward specific molecular patterns. We recently proposed and demonstrated that these functions could be afforded by the spontaneous ordering of ultrashort nucleic acids oligomers into Liquid Crystal (LC) phases. In such supramolecular assemblies, duplex-forming oligomers are held in average end-to-end contact to form chemically discontinuous but physically continuous double helices. Using blunt ended duplexes, we found that LC formation could both provide molecular selection mechanisms and boost inter-oligomer ligation. This paper provides an essential extension to this notion by investigating the catalytic effects of LC ordering in duplexes with mutually interacting overhangs. Specifically, we studied the influence of LC ordering of 5'-hydroxy-3'-phosphate partially self-complementary DNA 14mers with 3'-CG sticky-ends, on the efficiency of non-enzymatic ligation reaction induced by water-soluble carbodiimide EDC as condensing agent. We investigated the ligation products in mixtures of DNA with poly-ethylene glycol (PEG) at three PEG concentrations at which the system phase separates creating DNA-rich droplets that organize into isotropic, nematic LC and columnar LC phases. We observe remarkable LC-enhanced chain lengthening, and we demonstrate that such lengthening effectively promotes and stabilizes LC domains, providing the kernel of a positive feedback cycle by which LC ordering promotes elongation, in turn stabilizing the LC ordering.

  5. Use of Ligated Segments of Rabbit Small Intestine in Experimental Shigellosis1

    PubMed Central

    Arm, H. G.; Floyd, T. M.; Faber, J. E.; Hayes, J. R.

    1965-01-01

    Arm, H. G. (Naval Medical Research Institute, Bethesda, Md.), T. M. Floyd, J. E. Faber, and J. R. Hayes. Use of ligated segments of rabbit small intestine in experimental shigellosis. J. Bacteriol. 89:803–809. 1965.—Inoculation of ligated segments of small intestine in living rabbits with broth cultures or resting-cell suspensions of recently isolated strains of Shigella caused distension of the segments by accumulation of exudate within 12 hr. Histological changes characteristic of an inflammatory response were similar to those of human bacillary dysentery. Tissue response and accumulation of exudate preceded demonstrable increase in numbers of shigellae inoculated as 2 × 1010 resting cells. Capability of shigellae to provoke intestinal response was not related to any particular serological group. The active principles concerned with eliciting intestinal response were associated only with preparations containing living organisms. Ability of recently isolated strains to elicit response diminished rapidly during culture on artificial media. The capability was preserved indefinitely by lyophilization soon after isolation from acute bacillary dysentery infections of man. Advantages of using shigellae recently isolated for investigating possible mechanisms of pathogenesis were indicated. During the summer months, the rabbit small intestine was refractory to the activity of shigellae, and positive responses were not observed. Use of ligated segments of rabbit small intestine qualified as an indicator of virulence for the rabbit; and, virulence for the rabbit showed a high degree of correlation with a short period of culture of shigellae on artificial media after isolation from human bacillary dysentery infections. Images PMID:14273664

  6. [Post-translational ligation of split CFTR severed before TMD2 and its chloride channel function].

    PubMed

    Zhu, Fuxiang; Gong, Xiandi; Liu, Zelong; Yang, Shude; Qu, Huige; Chi, Xiaoyan

    2010-12-01

    Mutations of cystic fibrosis transmembrane conductance regulator (CFTR) gene leads to cystic fibrosis, an autosomal recessive genetic disorder affecting a number of organs including the lung airways, pancreas and sweat glands. In order to investigate the post-translational ligation of CFTR with reconstructed functional chloride ion channel and the split Ssp DnaB intein-mediated protein trans-splicing was explored to co-deliver CFTR gene into eukaryotic cells with two vectors. The human CFTR cDNA was split after Glu838 codon before the second transmembrane dome (TMD2) into two halves of N- and C-parts and fused with the coding sequences of split Ssp DnaB intein. Pair of eukaryotic expression vectors pEGFP-NInt and pEYFP-IntC were constructed by inserting them into the vectors pEGFP-N1 and pEYFP-N1 respectively. The transient expression was carried out for observing the ligation of CFTR by Western blotting and recording the chloride current by patch clamps when cotransfection of the pair of vectors into baby hamster kidney (BHK) cells. The results showed that an obvious protein band proven to be ligated intact CFTR can be seen and a higher chloride current and activity of chloride channel were recorded after cotransfection. These data demonstrated that split Ssp DnaB intein could be used as a strategy in delivering CFTR gene by two vectors providing evidence for application of dual adeno-associated virus (AAV) vectors to overcome the limitation of packaging size in cystic fibrosis gene therapy.

  7. Unique ligation properties of eukaryotic NAD+-dependent DNA ligase from Melanoplus sanguinipes entomopoxvirus.

    PubMed

    Lu, Jing; Tong, Jie; Feng, Hong; Huang, Jianmin; Afonso, Claudio L; Rock, Dan L; Barany, Francis; Cao, Weiguo

    2004-09-01

    The eukaryotic Melanoplus sanguinipes entomopoxvirus (MsEPV) genome reveals a homologous sequence to eubacterial nicotinamide adenine dinucleotide (NAD(+))-dependent DNA ligases [J. Virol. 73 (1999) 533]. This 522-amino acid open reading frame (ORF) contains all conserved nucleotidyl transferase motifs but lacks the zinc finger motif and BRCT domain found in conventional eubacterial NAD(+) ligases. Nevertheless, cloned MsEPV ligase seals DNA nicks in a NAD(+)-dependent fashion, while adenosine 5'-monophosphate (ATP) cannot serve as an adenylation cofactor. The ligation activity of MsEPV ligase requires Mg(2+) or Mn(2+). MsEPV ligase seals sticky ends efficiently, but has little activity on 1-nucleotide gap or blunt-ended DNA substrates even in the presence of polyethylene glycol. In comparison, bacterial NAD(+)-dependent ligases seal blunt-ended DNA substrates in the presence of polyethylene glycol. MsEPV DNA ligase readily joins DNA nicks with mismatches at either side of the nick junction, except for mismatches at the nick junction containing an A base in the template strand (A/A, G/A, and C/A). MsEPV NAD(+)-dependent DNA ligase can join DNA probes on RNA templates, a unique property that distinguishes this enzyme from other conventional bacterial NAD(+) DNA ligases. T4 ATP-dependent DNA ligase shows no detectable mismatch ligation at the 3' side of the nick but substantial 5' T/G mismatch ligation on an RNA template. In contrast, MsEPV ligase joins mismatches at the 3' side of the nick more frequently than at the 5' side of the nick on an RNA template. The complementary specificities of these two enzymes suggest alternative primer design for genomic profiling approaches that use allele-specific detection directly from RNA transcripts.

  8. Ligation activity of fragmented ribozymes in frozen solution: implications for the RNA world

    PubMed Central

    Vlassov, Alexander V.; Johnston, Brian H.; Landweber, Laura F.; Kazakov, Sergei A.

    2004-01-01

    A vexing difficulty of the RNA world hypothesis is how RNA molecules of significant complexity could ever have evolved given their susceptibility to degradation. One way degradation might have been reduced is through low temperature. Here we report that truncated and fragmented derivatives of the hairpin ribozyme can catalyze ligation of a wide variety of RNA molecules to a given sequence in frozen solution despite having little or no activity under standard solution conditions. These results suggest that complex RNAs could have evolved in freezing environments on the early earth and perhaps elsewhere. PMID:15161960

  9. Ligation of the left hepatic vein for dilated intrahepatic collaterals late after fontan operation.

    PubMed

    Park, Chun Soo; Park, Jeong-Jun; Park, In-Sook; Goo, Hyun Woo

    2014-07-01

    A 17-year-old male presented with two episodes of syncope, cyanosis, and exercise intolerance 13 years after the Fontan operation. Echocardiography and magnetic resonance imaging showed dilated intrahepatic collaterals, which drained into the atrium through the left hepatic vein, and 24-hour Holter monitoring revealed sinus node dysfunction. We performed ligation of the left hepatic vein using intrahepatic collaterals as channels draining hepatic venous blood into the Fontan pathway, and implanted an epicardial dual chamber pacemaker. At one-year follow-up, the patient remained asymptomatic and his cardiac performance was much improved.

  10. [Extraperitoneal ligation herniorraphy by the acute infectious diseases of the abdominal cavity in children].

    PubMed

    Ignat'ev, R O; Bataev, S M

    2012-01-01

    Surgery on the reason of the "acute abdomen" in children often reveals the persisting vaginal peritoneal defects, which further lead to hernia formation. 23 children (aged 4-15 years) were operated on the acute uncomplicated appendicitis (n=10), acute mesadenitis (n=3), appendicular local and pelvioperitonitis (n=9) and ovary apoplexia (n=1). Inguinal hernia was revealed in all patients during laparoscopy. After videoendoscopic sanation of the abdomen and appendectomy (if it was necessary) the extraperitoneal ligation herniorraphy in author's modification was performed. The were no cases of abdominal complications as well as hernia recurrence among the treated patients.

  11. A Novel Method to Quantify RNA–Protein Interactions In Situ Using FMTRIP and Proximity Ligation

    PubMed Central

    Zurla, C.; Jung, J.; Blanchard, E.L.; Santangelo, P.J.

    2017-01-01

    RNA binding proteins (RBP) and small RNAs regulate the editing, localization, stabilization, translation, and degradation of ribonucleic acids (RNAs) through their interactions with specific cis-acting elements within target RNAs. Here, we describe a novel method to detect protein–mRNA interactions, which combines FLAG-peptide modified, multiply-labeled tetravalent RNA imaging probes (FMTRIPs) with proximity ligation (PLA), and rolling circle amplification (RCA). This assay detects native RNA in a sequence specific and single RNA sensitive manner, and PLA allows for the quantification and localization of protein–mRNA interactions with single-interaction sensitivity. PMID:27662876

  12. Development and validation of an oligonucleotide ligation assay to detect lamivudine resistance in hepatitis B virus.

    PubMed

    Beck, Ingrid A; Payant, Rachel; Ngo-Giang-Huong, Nicole; Khamduang, Woottichai; Laomanit, Laddawan; Jourdain, Gonzague; Frenkel, Lisa M

    2016-07-01

    Treatment of chronic hepatitis B virus (HBV) infection with lamivudine-monotherapy rapidly selects mutant variants in a high proportion of individuals. Monitoring lamivudine resistance by consensus sequencing is costly and insensitive for detection of minority variants. An oligonucleotide ligation assay (OLA) for HBV lamivudine-resistance was developed and compared to consensus sequencing. Both assays detected drug resistance mutations in 35/64 (54.7%) specimens evaluated, and OLA detected minority mutants in an additional six (9.4%). OLA may offer a sensitive and inexpensive alternative to consensus sequencing for detection of HBV drug resistance in resource-limited settings.

  13. Biomimetic Synthesis of Insulin Enabled by Oxime Ligation and Traceless "C-Peptide" Chemical Excision.

    PubMed

    Thalluri, Kishore; Kou, Binbin; Gelfanov, Vasily; Mayer, John P; Liu, Fa; DiMarchi, Richard D

    2017-02-03

    For decades, insulin has represented a preeminent synthetic target. Recently introduced "biomimetic" strategies based on convertible single-chain precursors require incorporation of a chemical linker or a unique proteolytic site, which limits their practicality. In this approach the A- and B-chains are linked by two sequential oxime ligations followed by disulfide bond formation under redox conditions and linker excision by diketopiperazine (DKP) formation and ester hydrolysis, yielding native two-chain insulin. The method is expected to be applicable to any member of the insulin superfamily.

  14. Chip ligating human genomic DNA serves as storage material and template for polymerase chain reaction.

    PubMed

    Hanaoka, T; Takai, O; Takahashi, K; Tsugane, S

    2003-03-01

    A chip was developed to store DNA for medical research. The optional restriction site fixed on the chip can randomly ligate with whole human genomic DNA treated by the corresponding restriction enzyme. PCR can then use the chip as template DNA. Moreover, a chip fixing two restriction sites (e.g. EcoRI and HindIII) showed the amplification by PCR for any location of genomic DNA. Repetitive PCRs have confirmed that a DNA chip can be stored by at -4 degrees C for 2 years.

  15. HF‐Free Boc Synthesis of Peptide Thioesters for Ligation and Cyclization

    PubMed Central

    Raz, Richard; Burlina, Fabienne; Ismail, Mohamed; Downward, Julian; Li, Jiejin; Smerdon, Stephen J.; Quibell, Martin; White, Peter D.

    2016-01-01

    Abstract We have developed a convenient method for the direct synthesis of peptide thioesters, versatile intermediates for peptide ligation and cyclic peptide synthesis. The technology uses a modified Boc SPPS strategy that avoids the use of anhydrous HF. Boc in situ neutralization protocols are used in combination with Merrifield hydroxymethyl resin and TFA/TMSBr cleavage. Avoiding HF extends the scope of Boc SPPS to post‐translational modifications that are compatible with the milder cleavage conditions, demonstrated here with the synthesis of the phosphorylated protein CHK2. Peptide thioesters give easy, direct, access to cyclic peptides, illustrated by the synthesis of cyclorasin, a KRAS inhibitor. PMID:27654901

  16. Associating liver partition and portal vein ligation for staged hepatectomy: From technical evolution to oncological benefit

    PubMed Central

    Li, Jun; Ewald, Florian; Gulati, Amit; Nashan, Björn

    2016-01-01

    Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a novel approach in liver surgery that allows for extensive resection of liver parenchyma by inducing a rapid hypertrophy of the future remnant liver. However, recent reports indicate that not all patients eligible for ALPPS will benefit from this procedure. Therefore, careful patient selection will be necessary to fully exploit possible benefits of ALPPS. Here, we provide a comprehensive overview of the technical evolution of ALPPS with a special emphasis on safety and oncologic efficacy. Furthermore, we review the contemporary literature regarding indication and benefits, but also limitations of ALPPS. PMID:26981186

  17. Enlargement of the receptive field size to low intensity mechanical stimulation in the rat spinal nerve ligation model of neuropathy.

    PubMed

    Suzuki, R; Kontinen, V K; Matthews, E; Williams, E; Dickenson, A H

    2000-06-01

    One characteristic of plasticity after peripheral tissue or nerve damage is receptive field reorganization, and enlargement of receptive field size has been suggested to occur in certain models of neuropathic pain. The aim of the present study was to explore whether enlargement of neuronal receptive fields could contribute to the mechanical allodynia found on the ipsilateral paw in the spinal nerve ligation model of neuropathy. After ligation of L(5)-L(6) spinal nerves, all rats developed behavioral signs of mechanical allodynia, while the sham-operated control group displayed no such changes. The characteristics of the evoked responses of the neurones recorded in the dorsal horn of the rats were similar between the spinal nerve ligation, the sham operated control group, and the nonoperated control group, except for spontaneous activity, which was significantly increased in the spinal nerve ligation group. The mean size of the receptive field on the ipsilateral hindpaw, mapped using low-intensity stimulation with 9-g von Frey hair, was significantly increased in the spinal nerve ligation group, as compared to the sham-operated group. No significant difference was seen with 15- or 75-g von Frey hairs. The distribution of the receptive fields over the plantar surface of the paw was similar between the study groups. The enlargement of receptive field for non-noxious touch could be an indication of central sensitization in this model.

  18. Alterations in plaque accumulation and gingival inflammation promoted by treatment with self-ligating and conventional orthodontic brackets

    PubMed Central

    Cardoso, Mauricio de Almeida; Saraiva, Patrícia Pinto; Maltagliati, Liliana Ávila; Rhoden, Fernando Kleinübing; Costa, Carla Cristina Alvarenga; Normando, David; Capelozza, Leopoldino

    2015-01-01

    OBJECTIVE: The aim of the present study was to evaluate, comparatively, the periodontal response during orthodontic treatment performed with self-ligating and conventional brackets. METHODS: Sixteen Caucasian individuals of both sexes, aged between 12 and 16 years old and in permanent dentition were selected. Eight individuals were treated with conventional brackets installed on the lower dental arch and self-ligating brackets on the upper arch. Another eight individuals received self-ligating brackets in the lower arch and conventional brackets in the upper arch. The subjects received material and instructions for oral hygiene. Visible plaque index (VPI), gingival bleeding index (GBI) and clinical attachment level (CAL) were evaluated just after installation of orthodontic appliances, and 30, 60 and 180 days later. Mann-Whitney test was used to compare differences between groups (self-ligating and conventional), two-way ANOVA followed by Tukey's test was used to assess CAL at each site of each tooth. Significance level was set at 5%. RESULTS: No significant changes were found with regard to the assessed parameters (VPI, GBI and CAL) in either one of the systems. CONCLUSION: No significant changes were found with regard to the periodontal response to orthodontic treatment for the variables assessed and between subjects receiving passive self-ligating and conventional brackets. All individuals had received oral hygiene instructions and had their periodontal conditions monitored. PMID:25992985

  19. Disinclusion of unerupted teeth by mean of self-ligating brackets: Effect of blood contamination on shear bond strength

    PubMed Central

    Sfondrini, Maria F.; Gatti, Sara; Gandini, Paola

    2013-01-01

    Objectives: The aim of this study was to assess the effect of blood contamination on the shear bond strength and failure site of three different orthodontic self-ligating brackets. Study Design: 240 bovine permanent mandibular incisors were randomly divided into 12 groups of 20 specimens each. Orthodontic self-ligating brackets were tested under four different enamel surface conditions: a) dry, b) blood contamination before priming, c) blood contamination after priming, d) blood contamination before and after priming. Brackets were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bond strength values and adhesive failure rate were recorded. Statistical analysis was performed using ANOVA and Tukey tests (strength values), and Chi squared test (ARI Scores). Results: Non-contaminated enamel surfaces showed highest bond strengths for all self ligating brackets. Under blood-contamination shear bond strengths lowered for all brackets tested. Groups contaminated before and after primer application showed the lowest shear bond strength. Significant differences in debond locations were found among the groups under the various enamel surface conditions. Conclusions: Blood contamination of enamel during the bonding procedure lowers bond strength values of self ligating brackets, expecially when contamination occur in different times of the bonding procedure. Key words:Disinclusion, self ligating brackets, blood, contamination, enamel, orthodontics, oral surgery. PMID:23229253

  20. Coated Rectangular Composite Archwires: A Comparison Of Self-Ligating And Conventional Bracket Systems During Sliding Mechanics

    NASA Astrophysics Data System (ADS)

    Woods, David Keith

    The purpose of this study was to analyze the resistance to sliding of coated rectangular fiber reinforced composite archwires using various brackets systems and second-order bracket angulations. Resistance to sliding was investigated for eight bracket systems: six self-ligating brackets (four passive and two passive-active) and two conventional brackets. A rectangular fiber reinforced composite archwire of 0.019 x 0.025-in dimension from BiomersRTM SimpliClear was drawn through a three-bracket model system at ten millimeters per minute for 2.5 millimeters. For each bracket, the resistance to sliding was measured at four bracket angulations (0°, 2.5°, 5°, and 10°) in a dry state at room temperature. The fiber reinforced composite archwire produced the lowest sliding resistance with the passive self-ligating bracket system (Damon DQ) at each bracket angulation tested. Overall, self-ligating bracket systems generated lower sliding resistance than conventionally ligated systems, and one passive/active self-ligating bracket system (In-Ovation-R). There was a significant increase in resistance to sliding as bracket angulation increased for all bracket systems tested. Microscopic analysis revealed increased perforation of the archwire coating material as bracket angulations were increased. Our findings show that the rectangular fiber reinforced composite archwire may be acceptable for sliding mechanics during the intermediate stages of orthodontic tooth movement, however more long-term studies are needed.

  1. [Pancreatoduodenectomy for invasive carcinoma of the head of the pancreas with ligation of the inferior pancreaticoduodenal artery performed first].

    PubMed

    Horiguchi, Akihiko; Ishihara, Shin; Ito, Masahiro; Asano, Yukio; Yamamoto, Toshiyuki; Miyakawa, Shuichi

    2011-05-01

    The ideal surgical procedure for treating pancreatic cancer achieves radical excision in a minimally invasive manner and allows rapid transition to adjuvant chemotherapy. If the afferent artery to the pancreatic head is not ligated until the latter half of the surgery, congestion of the pancreaticoduodenal vein may occur, leading to phleborrhagia and increased intraoperative hemorrhage. Ligation of the afferent artery, i.e., the inferior pancreaticoduodenal artery (IPDA), in the first half of the surgery may prevent the occurrence of hemorrhage due to congestion. Early ligation of the IPDA is also useful in ensuring the success of radical dissection of the plexus around the superior mesenteric artery or the no. 14 lymph node. We have been performing pancreaticoduodenectomies with antecedent IPDA ligation since 2005 and have found that the percentage of R0 versus R1 and R2 has increased compared with that when standard pancreaticoduodenectomies were performed. Preemptive ligation of the IPDA early in pancreaticoduodenectomy for invasive pancreatic cancer is a useful method for reducing blood loss and achieving R0 resection in a thorough yet efficient manner.

  2. Controlling tetramer formation, subunit rotation and DNA ligation during Hin-catalyzed DNA inversion

    PubMed Central

    Chang, Yong; Johnson, Reid C.

    2015-01-01

    Two critical steps controlling serine recombinase activity are the remodeling of dimers into the chemically active synaptic tetramer and the regulation of subunit rotation during DNA exchange. We identify a set of hydrophobic residues within the oligomerization helix that controls these steps by the Hin DNA invertase. Phe105 and Met109 insert into hydrophobic pockets within the catalytic domain of the same subunit to stabilize the inactive dimer conformation. These rotate out of the catalytic domain in the dimer and into the subunit rotation interface of the tetramer. About half of residue 105 and 109 substitutions gain the ability to generate stable synaptic tetramers and/or promote DNA chemistry without activation by the Fis/enhancer element. Phe106 replaces Phe105 in the catalytic domain pocket to stabilize the tetramer conformation. Significantly, many of the residue 105 and 109 substitutions support subunit rotation but impair ligation, implying a defect in rotational pausing at the tetrameric conformer poised for ligation. We propose that a ratchet-like surface involving Phe105, Met109 and Leu112 within the rotation interface functions to gate the subunit rotation reaction. Hydrophobic residues are present in analogous positions in other serine recombinases and likely perform similar functions. PMID:26056171

  3. Design and validation of DNA libraries for multiplexing proximity ligation assays.

    PubMed

    Gobet, Nicolas; Ketterer, Simon; Meier, Matthias

    2014-01-01

    Here, we present an in silico, analytical procedure for designing and testing orthogonal DNA templates for multiplexing of the proximity ligation assay (PLA). PLA is a technology for the detection of protein interactions, post-translational modifications, and protein concentrations. To enable multiplexing of the PLA, the target information of antibodies was encoded within the DNA template of a PLA, where each template comprised four single-stranded DNA molecules. Our DNA design procedure followed the principles of minimizing the free energy of DNA cross-hybridization. To validate the functionality, orthogonality, and efficiency of the constructed template libraries, we developed a high-throughput solid-phase rolling-circle amplification assay and solid-phase PLA on a microfluidic platform. Upon integration on a microfluidic chip, 640 miniaturized pull-down assays for oligonucleotides or antibodies could be performed in parallel together with steps of DNA ligation, isothermal amplification, and detection under controlled microenvironments. From a large computed PLA template library, we randomly selected 10 template sets and tested all DNA combinations for cross-reactivity in the presence and absence of antibodies. By using the microfluidic chip application, we determined rapidly the false-positive rate of the design procedure, which was less than 1%. The combined theoretical and experimental procedure is applicable for high-throughput PLA studies on a microfluidic chip.

  4. Sequencing by Cyclic Ligation and Cleavage (CycLiC) directly on a microarray captured template.

    PubMed

    Mir, Kalim U; Qi, Hong; Salata, Oleg; Scozzafava, Giuseppe

    2009-01-01

    Next generation sequencing methods that can be applied to both the resequencing of whole genomes and to the selective resequencing of specific parts of genomes are needed. We describe (i) a massively scalable biochemistry, Cyclical Ligation and Cleavage (CycLiC) for contiguous base sequencing and (ii) apply it directly to a template captured on a microarray. CycLiC uses four color-coded DNA/RNA chimeric oligonucleotide libraries (OL) to extend a primer, a base at a time, along a template. The cycles comprise the steps: (i) ligation of OLs, (ii) identification of extended base by label detection, and (iii) cleavage to remove label/terminator and undetermined bases. For proof-of-principle, we show that the method conforms to design and that we can read contiguous bases of sequence correctly from a template captured by hybridization from solution to a microarray probe. The method is amenable to massive scale-up, miniaturization and automation. Implementation on a microarray format offers the potential for both selection and sequencing of a large number of genomic regions on a single platform. Because the method uses commonly available reagents it can be developed further by a community of users.

  5. Electrochemical detection of aqueous Ag+ based on Ag+-assisted ligation reaction

    NASA Astrophysics Data System (ADS)

    Miao, Peng; Han, Kun; Wang, Bidou; Luo, Gangyin; Wang, Peng; Chen, Mingli; Tang, Yuguo

    2015-03-01

    In this work, a novel strategy to fabricate a highly sensitive and selective biosensor for the detection of Ag+ is proposed. Two DNA probes are designed and modified on a gold electrode surface by gold-sulfur chemistry and hybridization. In the presence of Ag+, cytosine-Ag+-cytosine composite forms and facilitates the ligation event on the electrode surface, which can block the release of electrochemical signals labeled on one of the two DNA probes during denaturation process. Ag+ can be sensitively detected with the detection limit of 0.1 nM, which is much lower than the toxicity level defined by U.S. Environmental Protection Agency. This biosensor can easily distinguish Ag+ from other interfering ions and the performances in real water samples are also satisfactory. Moreover, the two DNA probes are designed to contain the recognition sequences of a nicking endonuclease, and the ligated DNA can thus be cleaved at the original site. Therefore, the electrode can be regenerated, which allows the biosensor to be reused for additional tests.

  6. Electrochemical detection of aqueous Ag+ based on Ag+-assisted ligation reaction.

    PubMed

    Miao, Peng; Han, Kun; Wang, Bidou; Luo, Gangyin; Wang, Peng; Chen, Mingli; Tang, Yuguo

    2015-03-17

    In this work, a novel strategy to fabricate a highly sensitive and selective biosensor for the detection of Ag(+) is proposed. Two DNA probes are designed and modified on a gold electrode surface by gold-sulfur chemistry and hybridization. In the presence of Ag(+), cytosine-Ag(+)-cytosine composite forms and facilitates the ligation event on the electrode surface, which can block the release of electrochemical signals labeled on one of the two DNA probes during denaturation process. Ag(+) can be sensitively detected with the detection limit of 0.1 nM, which is much lower than the toxicity level defined by U.S. Environmental Protection Agency. This biosensor can easily distinguish Ag(+) from other interfering ions and the performances in real water samples are also satisfactory. Moreover, the two DNA probes are designed to contain the recognition sequences of a nicking endonuclease, and the ligated DNA can thus be cleaved at the original site. Therefore, the electrode can be regenerated, which allows the biosensor to be reused for additional tests.

  7. Dang Gui Bu Xue Tang ameliorates coronary artery ligation-induced myocardial ischemia in rats.

    PubMed

    Chunhua, Ma; Hongyan, Long; Weina, Zhu; Xiaoli, He; Yajie, Zhang; Jie, Ruan

    2017-01-28

    Dang The present study was designed to investigate cardioprotective effects of Dang Gui Bu Xue Tang (DGBUT) on coronary artery ligation-induced myocardial ischemia. Myocardial ischemia (MI) model was induced in SD rats by surgical ligation of the left anterior descending coronary artery. ST segment elevation of Electrocardiograph (ECG) infarct size, levels of lactate dehydrogenase (LDH), creatine kinase (CK), glutathione (GSH) and catalase (CAT), catalase (SOD), malondialdehyde (MDA), and inflammatory cytokines and phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, p38, c-Jun NH2 terminal kinases (JNK), nuclear factor (NF)-κBp65, inhibitory kappa B (IκB) α, IκB kinase (IKK) α and IKKβ were evaluated in rats treated with or without DGBUT. DGBUT treatment significantly reduced the elevation of the ST segment of ECG, the myocardial infarct size of MI. The level of LDH, CK and MDA were suppressed, the contents of SOD, GSH and CAT were enhanced with DGBUT. The elevated concentration of inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and IL-6 in MI rats were effectively reversed by the DGBUT administration. Also, highly expressed p-JNK, p-ERK, p-p38, p-NF-κBp65, p-IκBα, p-IKKα and p-IKKβ in MI rats were restored respectively by DGBUT treatment. The protective effect of DGBUT against MI injury might be associated with MAPK/NF-кB pathway.

  8. A N3S(thioether)-Ligated CuII-Superoxo with Enhanced Reactivity

    PubMed Central

    Kim, Sunghee; Lee, Jung Yoon; Cowley, Ryan E.; Ginsbach, Jake W.; Siegler, Maxime A.; Solomon, Edward I.; Karlin, Kenneth D.

    2015-01-01

    Previous efforts to synthesize a cupric superoxide complex possessing a thioether donor have resulted in the formation of an end-on trans-peroxodicopper(II) species, [{(Ligand)CuII}2(μ-1,2-O22−)]2+. Redesign/modification of previous N3S tetradentate ligands has now allowed for the stabilization of the monomeric, superoxide product possessing a S(thioether)-ligation, [(DMAN3S)CuII(O2•−)]+ (2S), as characterized by UV-vis and resonance Raman (rR) spectroscopies. This complex mimics the putative CuII(O2•−) active species of the copper monooxygenase PHM and exhibits enhanced reactivity towards both O-H and C-H substrates in comparison to close analogues [(L)CuII(O2•−)]+, where L contains only nitrogen donor atoms. Cu-S(thioether) ligation with its weaker donor ability (relative to an N-donor) are demonstrated by comparisons to the chemistry of analogue compounds. PMID:25697226

  9. Taurocholic Acid Prevents Biliary Damage Induced by Hepatic Artery Ligation in Cholestatic Rats

    PubMed Central

    Glaser, Shannon; Onori, Paolo; Gaudio, Eugenio; Ueno, Yoshiyuki; Pannarale, Luigi; Franchitto, Antonio; Francis, Heather; Mancinelli, Romina; Carpino, Guido; Venter, Julie; White, Mellanie; Kopriva, Shelley; Vetuschi, Antonella; Sferra, Roberta; Alpini, Gianfranco

    2010-01-01

    Background Ischemic injury by hepatic artery ligation (HAL) during obstructive cholestasis induced by bile duct ligation (BDL) results in bile duct damage, which can be prevented by administration of VEGF-A. The potential regulation of VEGF and VEGF receptor expression and secretion by bile acids in BDL with HAL is unknown. Aims We evaluated whether taurocholic acid (TC) can prevent HAL-induced cholangiocyte damage via the alteration of VEGFR-2 and/or VEGF-A expression. Methods Utilizing BDL, BDL+TC, BDL+HAL, BDL+HAL+TC, and BDL+HAL+wortmannin+TC treated rats, we evaluated cholangiocyte apoptosis, proliferation, and secretion as well VEGF-A and VEGFR-2 expression by immunohistochemistry. In vitro, we evaluated the effects of TC on cholangiocyte secretion of VEGF-A and the dependence of TC-induced proliferation on the activity of VEGFR-2. Results In BDL rats with HAL, chronic feeding of TC prevented HAL-induced loss of bile ducts and HAL-induced decreased cholangiocyte secretion. TC also prevented HAL-inhibited VEGF-A and VEGFR-2 expression in liver sections and HAL-induced circulating VEGF-A levels, which were blocked by wortmannin administration. In vitro, TC stimulated increased VEGF-A secretion by cholangiocytes, which was blocked by wortmannin and stimulated cholangiocyte proliferation that was blocked by VEGFR-2 kinase inhibitor. Conclusion TC prevented HAL-induced biliary damage by upregulation of VEGF-A expression. PMID:20303838

  10. Bile duct ligation in mice: induction of inflammatory liver injury and fibrosis by obstructive cholestasis.

    PubMed

    Tag, Carmen G; Sauer-Lehnen, Sibille; Weiskirchen, Sabine; Borkham-Kamphorst, Erawan; Tolba, René H; Tacke, Frank; Weiskirchen, Ralf

    2015-02-10

    In most vertebrates, the liver produces bile that is necessary to emulsify absorbed fats and enable the digestion of lipids in the small intestine as well as to excrete bilirubin and other metabolic products. In the liver, the experimental obstruction of the extrahepatic biliary system initiates a complex cascade of pathological events that leads to cholestasis and inflammation resulting in a strong fibrotic reaction originating from the periportal fields. Therefore, surgical ligation of the common bile duct has become the most commonly used model to induce obstructive cholestatic injury in rodents and to study the molecular and cellular events that underlie these pathophysiological mechanisms induced by inappropriate bile flow. In recent years, different surgical techniques have been described that either allow reconnection or reanastomosis after bile duct ligation (BDL), e.g., partial BDL, or other microsurgical methods for specific research questions. However, the most frequently used model is the complete obstruction of the common bile duct that induces a strong fibrotic response after 21 to 28 days. The mortality rate can be high due to infectious complications or technical inaccuracies. Here we provide a detailed surgical procedure for the BDL model in mice that induce a highly reproducible fibrotic response in accordance to the 3R rule for animal welfare postulated by Russel and Burch in 1959.

  11. Rapid synthesis of DNA-cysteine conjugates for expressed protein ligation

    SciTech Connect

    Lovrinovic, Marina; Niemeyer, Christof M. . E-mail: christof.niemeyer@uni-dortmund.de

    2005-09-30

    We report a rapid method for the covalent modification of commercially available amino-modified DNA oligonucleotides with a cysteine moiety. The resulting DNA-cysteine conjugates are versatile reagents for the efficient preparation of covalent DNA-protein conjugates by means of expressed protein ligation (EPL). The EPL method allows for the site-specific coupling of cysteine-modified DNA oligomers with recombinant intein-fusion proteins, the latter of which contain a C-terminal thioester enabling the mild and highly specific reaction with N-terminal cysteine compounds. We prepared a cysteine-modifier reagent in a single-step reaction which allows for the rapid and near quantitative synthesis of cysteine-DNA conjugates. The latter were ligated with the green fluorescent protein mutant EYFP, recombinantly expressed as an intein-fusion protein, allowing for the mild and selective formation of EYFP-DNA conjugates in high yields of about 60%. We anticipate many applications of our approach, ranging from protein microarrays to the arising field of nanobiotechnology.

  12. Rubber band ligation for 750 cases of symptomatic hemorrhoids out of 2200 cases

    PubMed Central

    Nakeeb, Ayman M El; Fikry, Amir A; Omar, Waleed H; Fouda, Elyamani M; Metwally, Tito A El; Ghazy, Hosam E; Badr, Sabry A; Elkhar, Mohmed Y Abu; Elawady, Salih M; Elmoniam, Hisham H Abd; Khafagy, Waiel W; Morshed, Mosaad M; Lithy, Ramadan E El; Farid, Mohamed E

    2008-01-01

    AIM: To study the results for the treatment of symptomatic hemorrhoids using rubber band ligation (RBL) method. METHODS: A retrospective study for 750 patients who came to the colorectal unit from June, 1998 to September, 2006, data was retrieved from archived files. RBL was performed using the Mc Gown applicator on an outpatient basis. The patients were asked to return to out-patient clinic for follow up at 2 wk, 1 mo, 6 mo and through telephone call every 6 mo for 2 years). RESULTS: After RBL, 696 patients (92.8%) were cured with no difference in outcome for second or third degree hemorrhoids (P = 0.31). Symptomatic recurrence was detected in 11.04% after 2 years. A total of 52 patients (6.93%) had 77 complications from RBL which required no hospitalization. Complications were pain, rectal bleeding and vaso-vagal symptoms (4.13%, 4.13% and 1.33% of patients, respectively). At 1 mo there were a significant improvement in mean SF-36 scores over baseline in five items, while after 2 years there were improvement in all items over baseline, but not significant. No significant manometric changes after band ligation. CONCLUSION: RBL is a simple, safe and effective method for treating symptomatic second and third degree hemorrhoids as an out patient procedure with significant improvement in quality of life. RBL doesn’t alter ano-rectal functions. PMID:19030206

  13. Cost and efficacy comparison of in vitro fertilization and tubal anastomosis for women after tubal ligation

    PubMed Central

    Messinger, Lauren B.; Alford, Connie E.; Csokmay, John M.; Henne, Melinda B.; Mumford, Sunni L.; Segars, James H.; Armstrong, Alicia Y.

    2016-01-01

    Objective To compare cost and efficacy of tubal anastomosis to in vitro fertilization (IVF) in women who desired fertility after a tubal ligation. Design Cost-effectiveness analysis. Setting Not applicable. Patient(s) Not applicable. Intervention(s) Not applicable. Main Outcome Measure(s) Cost per ongoing pregnancy. Result(s) Cost per ongoing pregnancy for women after tubal anastomosis ranged from $16,446 to $223,482 (2014 USD), whereas IVF ranged from $32,902 to $111,679 (2014 USD). Across maternal age groups <35 and 35–40, years tubal anastomosis was more cost effective than IVF for ongoing pregnancy. Sensitivity analyses validated these findings across a wide range of ongoing pregnancy probabilities as well as costs per procedure. Conclusion(s) Tubal anastomosis was the most cost-effective approach for most women less than 41 years of age, whereas IVF was the most cost-effective approach for women aged ≥41 years who desired fertility after tubal ligation. A model was created that can be modified based on cost and success rates in individual clinics for improved patient counseling. PMID:26006734

  14. SpyLigase peptide–peptide ligation polymerizes affibodies to enhance magnetic cancer cell capture

    PubMed Central

    Fierer, Jacob O.; Veggiani, Gianluca; Howarth, Mark

    2014-01-01

    Individual proteins can now often be modified with atomic precision, but there are still major obstacles to connecting proteins into larger assemblies. To direct protein assembly, ideally, peptide tags would be used, providing the minimal perturbation to protein function. However, binding to peptides is generally weak, so assemblies are unstable over time and disassemble with force or harsh conditions. We have recently developed an irreversible protein–peptide interaction (SpyTag/SpyCatcher), based on a protein domain from Streptococcus pyogenes, that locks itself together via spontaneous isopeptide bond formation. Here we develop irreversible peptide–peptide interaction, through redesign of this domain and genetic dissection into three parts: a protein domain termed SpyLigase, which now ligates two peptide tags to each other. All components expressed efficiently in Escherichia coli and peptide tags were reactive at the N terminus, at the C terminus, or at internal sites. Peptide–peptide ligation enabled covalent and site-specific polymerization of affibodies or antibodies against the tumor markers epidermal growth factor receptor (EGFR) and HER2. Magnetic capture of circulating tumor cells (CTCs) is one of the most promising approaches to improve cancer prognosis and management, but CTC capture is limited by inefficient recovery of cells expressing low levels of tumor antigen. SpyLigase-assembled protein polymers made possible the isolation of cancerous cells expressing lower levels of tumor antigen and should have general application in enhancing molecular capture. PMID:24639550

  15. Ligation of the adhesion-GPCR EMR2 regulates human neutrophil function.

    PubMed

    Yona, Simon; Lin, Hsi-Hsien; Dri, Pietro; Davies, John Q; Hayhoe, Richard P G; Lewis, Sion M; Heinsbroek, Sigrid E M; Brown, K Alun; Perretti, Mauro; Hamann, Jörg; Treacher, David F; Gordon, Siamon; Stacey, Martin

    2008-03-01

    At present, approximately 150 different members of the adhesion-G protein-coupled receptor (GPCR) family have been identified in metazoans. Surprisingly, very little is known about their function, although they all possess large extracellular domains coupled to a seven-transmembrane domain, suggesting a potential role in cell adhesion and signaling. Here, we demonstrate how the human-restricted adhesion-GPCR, EMR2 (epidermal growth factor-like module-containing mucin-like hormone receptor), regulates neutrophil responses by potentiating the effects of a number of proinflammatory mediators and show that the transmembrane region is critical for adhesion-GPCR function. Using an anti-EMR2 antibody, ligation of EMR2 increases neutrophil adhesion and migration, and augments superoxide production and proteolytic enzyme degranulation. On neutrophil activation, EMR2 is rapidly translocated to membrane ruffles and the leading edge of the cell. Further supporting the role in neutrophil activation, EMR2 expression on circulating neutrophils is significantly increased in patients with systemic inflammation. These data illustrate a definitive function for a human adhesion-GPCR within the innate immune system and suggest an important role in potentiating the inflammatory response. Ligation of the adhesion-GPCR EMR2 regulates human neutrophil function.

  16. Probing Nitrosyl Ligation of Surface-Confined Metalloporphyrins by Inelastic Electron Tunneling Spectroscopy

    PubMed Central

    2013-01-01

    Complexes obtained by the ligation of nitric oxide (NO) to metalloporphyrins represent important model systems with biological relevance. Herein we report a molecular-level investigation of surface-confined cobalt tetraphenyl porphyrin (Co-TPP) species and their interaction with NO under ultrahigh vacuum conditions. It is demonstrated that individual NO adducts can be desorbed using the atomically sharp tip of a scanning tunneling microscope, whereby a writing process is implemented for fully saturated regular metalloporphyrin arrays. The low-energy vibrational characteristics of individual Co-TPP-nitrosyl complexes probed by inelastic electron tunneling spectroscopy (IETS) reveal a prominent signature at an energy of ≃31 meV. Using density functional theory-based IETS simulations—the first to be performed on such an extensive interfacial nanosystem—we succeed to reproduce the low-frequency spectrum for the NO-ligated complex and explain the absence of IETS activity for bare Co-TPP. Moreover, we can conclusively assign the IETS peak of NO-Co-TPP to a unique vibration mode involving the NO complexation site, namely, the in-plane Co–N–O rocking mode. In addition, we verify that the propensity rules previously designed on small aromatic systems and molecular fragments hold true for a metal–organic entity. This work notably permits one to envisage IETS spectroscopy as a sensitive tool to chemically characterize hybrid interfaces formed by complex metal–organic units and gaseous adducts. PMID:23718257

  17. Lcp1 Is a Phosphotransferase Responsible for Ligating Arabinogalactan to Peptidoglycan in Mycobacterium tuberculosis

    PubMed Central

    Harrison, James; Lloyd, Georgina; Joe, Maju; Lowary, Todd L.; Reynolds, Edward; Walters-Morgan, Hannah; Bhatt, Apoorva; Lovering, Andrew; Besra, Gurdyal S.

    2016-01-01

    ABSTRACT Mycobacterium tuberculosis, the etiological agent of tuberculosis (TB), has a unique cell envelope which accounts for its unusual low permeability and contributes to resistance against common antibiotics. The main structural elements of the cell wall consist of a cross-linked network of peptidoglycan (PG) in which some of the muramic acid residues are covalently attached to a complex polysaccharide, arabinogalactan (AG), via a unique α-l-rhamnopyranose–(1→3)-α-d-GlcNAc-(1→P) linker unit. While the molecular genetics associated with PG and AG biosynthetic pathways have been largely delineated, the mechanism by which these two major pathways converge has remained elusive. In Gram-positive organisms, the LytR-CpsA-Psr (LCP) family of proteins are responsible for ligating cell wall teichoic acids to peptidoglycan, through a linker unit that bears a striking resemblance to that found in mycobacterial arabinogalactan. In this study, we have identified Rv3267 as a mycobacterial LCP homolog gene that encodes a phosphotransferase which we have named Lcp1. We demonstrate that lcp1 is an essential gene required for cell viability and show that recombinant Lcp1 is capable of ligating AG to PG in a cell-free radiolabeling assay. PMID:27486192

  18. Pulmonary microthromboembolism by injection of sonicated autologous blood in rabbits with splenic artery ligations.

    PubMed

    Kietthubthew, S; Kisanuki, A; Asada, Y; Marutsuka, K; Funahara, Y; Sumiyoshi, A

    1997-01-01

    Chronic pulmonary thromboembolism (PTE) has been reported to play an important role in cardiac failure in thalassemic patients after splenectomy. However, the mechanism of PTE in these patients remains unclear. In this study, we attempted to establish an animal model of PTE seen in thalassemic patients after splenectomy. We divided New Zealand white rabbits into three groups: Group 1 was injected sonicated blood, II was injected non-sonicated blood after ligation of the splenic artery, and III was injected sonicated blood after ligation of the splenic artery. After injection of the sonicated blood, we counted the platelet number until 1 hour and the rabbits were sacrificed for histological examination. Platelets significantly decreased in number immediately after injection of the sonicated blood in Groups I and III. Many pulmonary thromboemboli composed mainly of platelets were found in Group III but not in other groups. These pathological changes seem to be partly similar to those of thalassemic patients after splenectomy. This animal model is thought to be useful to study the pathogenesis of pulmonary thromboembolism, especially in thalassemic patients after splenectomy.

  19. Intravenous injection of sonicated blood induces pulmonary microthromboembolism in rabbits with ligation of the splenic artery.

    PubMed

    Kisanuki, A; Kietthubthew, S; Asada, Y; Marutsuka, K; Funahara, Y; Sumiyoshi, A

    1997-01-15

    Pulmonary thromboembolism (PTE) is found in long hospitalized patients. Chronic PTE has been reported to play an important role in cardiac failure in thalassemic patients after splenectomy. However, the mechanism of PTE in these patients remains unclear. In this study, we attempted to establish an animal model of PTE. We divided New Zealand white rabbits into three groups: Group I was injected sonicated blood, II was injected non-sonicated blood after ligation of the splenic artery, and III was injected sonicated blood after ligation of the splenic artery. After injection of the sonicated blood, we examined the platelet counts every 10 minutes until 1 hour and the rabbits were sacrificed for histological examination. Platelets significantly decreased in number immediately after the injection of sonicated blood in Groups I and III. Many pulmonary thromboemboli composed mainly of platelets were found in Group III but not in other groups. These pathological changes seem to be partly similar to those of thalassemic patients after splenectomy. This animal model is thought to be useful to study the pathogenesis of pulmonary thromboembolism, especially in thalassemic patients after splenectomy.

  20. Harnessing chemoselective imine ligation for tethering bioactive molecules to platinum(IV) prodrugs.

    PubMed

    Wong, Daniel Yuan Qiang; Lau, Jia Yi; Ang, Wee Han

    2012-05-28

    Platinum(II) anticancer drugs are among the most effective and often used chemotherapeutic drugs. In recent years, there has been increasing interest in exploiting inert platinum(IV) scaffolds as a prodrug strategy to mitigate the limitations of platinum(II) anticancer complexes. In this prodrug strategy, the axial ligands are released concomitantly upon intracellular reduction to the active platinum(II) congener, offering the possibility of conjugating bioactive co-drugs which may synergistically enhance cytotoxicity on cancer cells. Existing techniques of tethering bioactive molecules to the axial positions of platinum(IV) prodrugs suffer from limited scope, poor yields and low reliability. This report explores the applications of current chemoselective ligation chemistries to platinum(IV) anticancer complexes with the aim of addressing the aforementioned limitations. Here, we describe the synthesis of a platinum(IV) complex bearing an aromatic aldehyde functionality and explored the scope of imine ligation with various hydrazide and aminooxy functionalized substrates. As a proof of concept, we tethered a six sequence long peptide mimetic (AMVSEF) of the anti-inflammatory protein, ANXA1.

  1. Single-incision-two port laparoscopic tubal ligation: A cost comparison and technique description

    PubMed Central

    Taşdemir, Nicel; Abalı, Remzi; Çelik, Cem; Aksu, Erson; Akkuş, Didem

    2015-01-01

    Objective Laparoscopic surgery is the principal minimally invasive technique that is used for the treatment of gynecologic pathologies. The single-incision laparoscopic surgery (SILS) is another innovation in minimally invasive medicine. The cost of the procedure correlates with the fundamental materials used to access the abdominal cavity and utilize trocars. Material and Methods We applied the single-incision tubal ligation procedure to three patients. A 15–20-mm vertical incision was made in the umbilicus. Two trocars were inserted through the same incision at different fascial regions after insufflation of the abdomen. A 5-mm bipolar cautery was introduced through the accessory trocar, and the mid-portion of the tubes was coagulated and cut bilaterally. Results The postoperative periods of the three patients were uneventful. All patients were discharged on the day of surgery. No major or minor complications occurred. Conclusion The cost for the abdominal access will drop about 82%. When we consider the low pricing for the tubal ligation procedure, the single-incision technique will be more applicable by this method. Moreover, patients will have the advantages of single-incision laparoscopic surgery with low cost. PMID:25788846

  2. Electronic Structure of Ligated CdSe Clusters: Dependence on DFT Methodology

    SciTech Connect

    Albert, VV; Ivanov, SA; Tretiak, S; Kilina, SV

    2011-07-07

    Simulations of ligated semiconductor quantum dots (QDs) and their physical properties, such as morphologies, QD-ligand interactions, electronic structures, and optical transitions, are expected to be very sensitive to computational methodology. We utilize Density Functional Theory (DFT) and systematically study how the choice of density functional, atom-localized basis set, and a solvent affects the physical properties of the Cd{sub 33}Se{sub 33} cluster ligated with a trimethyl phosphine oxide ligand. We have found that qualitative performance of all exchange-correlation (XC) functionals is relatively similar in predicting strong QD-ligand binding energy ({approx}1 eV). Additionally, all functionals predict shorter Cd-Se bond lengths on the QD surface than in its core, revealing the nature and degree of QD surface reconstruction. For proper modeling of geometries and QD-ligand interactions, however, augmentation of even a moderately sized basis set with polarization functions (e.g., LANL2DZ* and 6-31G*) is very important. A polar solvent has very significant implications for the ligand binding energy, decreasing it to 0.2-0.5 eV. However, the solvent model has a minor effect on the optoelectronic properties, resulting in persistent blue shifts up to {approx}0.3 eV of the low-energy optical transitions. For obtaining reasonable energy gaps and optical transition energies, hybrid XC functionals augmented by a long-range Hartree-Fock orbital exchange have to be applied.

  3. CD28 ligation increases macrophage suppression of T-cell proliferation.

    PubMed

    Silberman, Daniel; Bucknum, Amanda; Bartlett, Thomas; Composto, Gabriella; Kozlowski, Megan; Walker, Amanda; Werda, Amy; Cua, Jackelyn; Sharpe, Arlene H; Somerville, John E; Riggs, James E

    2012-07-01

    When compared to spleen or lymph node cells, resident peritoneal cavity cells respond poorly to T-cell activation in vitro. The greater proportional representation of macrophages in this cell source has been shown to actively suppress the T-cell response. Peritoneal macrophages exhibit an immature phenotype (MHC class II(lo), B7(lo)) that reduces their efficacy as antigen-presenting cells. Furthermore, these cells readily express inducible nitric oxide synthase (iNOS), an enzyme that promotes T-cell tolerance by catabolism of the limiting amino acid arginine. Here, we investigate the ability of exogenous T-cell costimulation to recover the peritoneal T-cell response. We show that CD28 ligation failed to recover the peritoneal T-cell response and actually suppressed responses that had been recovered by inhibiting iNOS. As indicated by cytokine ELISpot and neutralizing monoclonal antibody (mAb) treatment, this 'cosuppression' response was due to CD28 ligation increasing the number of interferon (IFN)-γ-secreting cells. Our results illustrate that cellular composition and cytokine milieu influence T-cell costimulation biology.Cellular & Molecular Immunology advance online publication, 23 April 2012; doi:10.1038/cmi.2012.13.

  4. Real-time ligation chain reaction for DNA quantification and identification on the FO-SPR.

    PubMed

    Knez, Karel; Spasic, Dragana; Delport, Filip; Lammertyn, Jeroen

    2015-05-15

    Different assays have been developed in the past years to meet point-of-care diagnostic tests requirements for fast and sensitive quantification and identification of targets. In this paper, we developed the ligation chain reaction (LCR) assay on the Fiber Optic Surface Plasmon Resonance (FO-SPR) platform, which enabled simultaneous quantification and cycle-to-cycle identification of DNA during amplification. The newly developed assay incorporated FO-SPR DNA melting assay, previously developed by our group. This required establishment of several assay parameters, including buffer ionic strength and thermal ramping speed as these parameters both influence the ligation enzyme performance and the hybridization yield of the gold nanoparticles (Au NPs) on the FO-SPR sensor. Quantification and identification of DNA targets was achieved over a wide concentration range with a calibration curve spanning 7 orders of magnitude and LOD of 13.75 fM. Moreover, the FO-SPR LCR assay could discriminate single nucleotide polymorphism (SNPs) without any post reaction analysis, featuring thus all the essential requirements of POC tests.

  5. "Bis-Click" Ligation of DNA: Template-Controlled Assembly, Circularisation and Functionalisation with Bifunctional and Trifunctional Azides.

    PubMed

    Yang, Haozhe; Seela, Frank

    2017-03-08

    Ligation and circularisation of oligonucleotides containing terminal triple bonds was performed with bifunctional or trifunctional azides. Both reactions are high yielding. Template-assisted bis-click ligation of two individual non-complementary oligonucleotide strands was accomplished to yield heterodimers exclusively. In this context, the template fulfils two functions: it accelerates the ligation reaction and controls product assembly (heterodimer vs. homodimer formation). Intermolecular bis-click circularisation of one oligonucleotide strand took place without template assistance. For construction of oligonucleotides with terminal triple bonds in the nucleobase side chain, 7- or 5-functionalised 7-deaza-dA and dU residues were used. These oligonucleotides are directly accessible by solid-phase synthesis. When trifunctional azides were employed instead of bifunctional linkers, functionalisation of the remaining azido group was performed with small molecules such as 1-ethynyl pyrene, biotin propargyl amide or with ethynylated oligonucleotides. By this means, branched DNA was constructed.

  6. Precise Quantitation of MicroRNA in a Single Cell with Droplet Digital PCR Based on Ligation Reaction.

    PubMed

    Tian, Hui; Sun, Yuanyuan; Liu, Chenghui; Duan, Xinrui; Tang, Wei; Li, Zhengping

    2016-12-06

    MicroRNA (miRNA) analysis in a single cell is extremely important because it allows deep understanding of the exact correlation between the miRNAs and cell functions. Herein, we wish to report a highly sensitive and precisely quantitative assay for miRNA detection based on ligation-based droplet digital polymerase chain reaction (ddPCR), which permits the quantitation of miRNA in a single cell. In this ligation-based ddPCR assay, two target-specific oligonucleotide probes can be simply designed to be complementary to the half-sequence of the target miRNA, respectively, which avoids the sophisticated design of reverse transcription and provides high specificity to discriminate a single-base difference among miRNAs with simple operations. After the miRNA-templated ligation, the ddPCR partitions individual ligated products into a water-in-oil droplet and digitally counts the fluorescence-positive and negative droplets after PCR amplification for quantification of the target molecules, which possesses the power of precise quantitation and robustness to variation in PCR efficiency. By integrating the advantages of the precise quantification of ddPCR and the simplicity of the ligation-based PCR, the proposed method can sensitively measure let-7a miRNA with a detection limit of 20 aM (12 copies per microliter), and even a single-base difference can be discriminated in let-7 family members. More importantly, due to its high selectivity and sensitivity, the proposed method can achieve precise quantitation of miRNAs in single-cell lysate. Therefore, the ligation-based ddPCR assay may serve as a useful tool to exactly reveal the miRNAs' actions in a single cell, which is of great importance for the study of miRNAs' biofunction as well as for the related biomedical studies.

  7. Mandibular arch orthodontic treatment stability using passive self-ligating and conventional systems in adults: A randomized controlled trial

    PubMed Central

    Wey, Mang Chek; Othman, Siti Adibah

    2017-01-01

    Objective This randomized controlled trial aimed to compare the stability of mandibular arch orthodontic treatment outcomes between passive self-ligating and conventional systems during 6 months of retention. Methods Fortyseven orthodontic patients with mild to moderate crowding malocclusions not requiring extraction were recruited based on inclusion criteria. Patients (mean age 21.58 ± 2.94 years) were randomized into two groups to receive either passive self-ligating (Damon® 3MX, n = 23) or conventional system (Gemini MBT, n = 24) orthodontic treatment. Direct measurements of the final sample comprising 20 study models per group were performed using a digital caliper at the debonding stage, and 1 month, 3 months, and 6 months after debonding. Paired t-test, independent t-test, and non-parametric test were used for statistical analysis. Results A significant increase (p < 0.01) in incisor irregularity was observed in both self-ligating and conventional system groups. A significant reduction (p < 0.01) in second interpremolar width was observed in both groups. Mandibular arch length decreased significantly (p = 0.001) in the conventional system group but not in the self-ligating system group. A similar pattern of stability was observed for intercanine width, first interpremolar width, intermolar width, and arch depth throughout the 6-month retention period after debonding. Comparison of incisor irregularity and arch dimension changes between self-ligating system and conventional system groups during the 6 months were non-significant. Conclusions The stability of treatment outcomes for mild to moderate crowding malocclusions was similar between the self-ligating system and conventional system during the first 6 months of retention. PMID:28127535

  8. Evaluation of the frictional resistance of conventional and self-ligating bracket designs using standardized archwires and dental typodonts.

    PubMed

    Henao, Sandra P; Kusy, Robert P

    2004-04-01

    The frictional behavior of four conventional and four self-ligating brackets were simulated using a mechanical testing machine. Analyses of the two-bracket types were completed by drawing samples of three standardized archwires through quadrants of typodont models in the dry/wet states. Pretreatment typodonts of an oral cavity featured progressively malocclused quadrants. As nominal dimensions of the archwires were increased, the drawing forces of all brackets increased at different rates. When coupled with a small wire, the self-ligating brackets performed better than the conventional brackets. For the 0.014-inch wires in the upper right quadrant, the maximum drawing forces averaged 125 and 810 cN for self-ligating and conventional brackets, respectively. When coupled with larger wires, various designs interchangeably displayed superior performance. For the 0.019- x 0.025-inch wires in the upper left quadrant, the maximum drawing forces averaged 1635 and 2080 cN for self-ligating and conventional brackets, respectively. As the malocclusion increased, the drawing forces increased. For example, in the least malocclused quadrant and with the smallest wire, maximum drawing forces for self-ligating and conventional brackets averaged 80 and 810 cN, respectively, whereas in the most malocclused quadrant tested with the same wire size, maximum drawing forces for self-ligating and conventional brackets averaged 870 and 1345 cN, respectively. For maximum values between the dry and wet states, significant differences between ambient states existed only for the In-Ovation brackets in the lower left quadrant. These test outcomes illustrated how bracket design, wire size, malocclusion, and ambient state influenced drawing forces.

  9. Comparative evaluation of efficacy of self-ligating interactive bracket with conventional preadjusted bracket: A clinical study

    PubMed Central

    Jayachandran, Balajee; Padmanabhan, Ratna; Vijayalakshmi, Devaki; Padmanabhan, Janardhanam

    2016-01-01

    Aims and Objectives: This clinical study was conducted to compare the interactive self-ligating twin brackets and the standard double width brackets for their efficiency in Rate of Retraction. Materials and Methods: A total of 20 patients with Angle's class I or class II or class III dento-alveolar malocclusions between the age group of 18-25 years were selected. 10 patients in each group both males and females were randomly selected for the study. Ten patients were bonded using conventional brackets (Group I) the other ten patients were bonded using Interactive self-ligating brackets (Group II). The Rate of retraction was quantified using the scanned models. Pretreatment and post treatment models were taken and scanned to measure the amount of Incisor movement and Anchor loss. Results: (1) Interactive Self-ligating brackets showed significant Rate of retraction when compared with conventional brackets on right and left quadrant. (Group I 0.545 ± .205: Group II 0.827 ± .208 P = .013*) (Group I 0.598 ± .160: Group II 0.804 ± .268 P = .071) (2) Interactive self-ligating brackets when compared with conventional brackets had significant amount of incisor movement on right and left quadrant. (Group I 3.51 ± .548: Group II 4.38 ± .1.06 P = .047*) and (Group I 3.66 ± .899: Group II 4.67 ± 1.02 P = .047*) (3) Conventional brackets showed significant Amount of Anchor loss when compared with that of Interactive self-ligating brackets on right and left quadrant. (Group I .948 ± .392: Group II 0.501 ± .229 P = .013*). In the left side (Group I 0.861 ± .464: Group II 0.498 ± .227 P = .060). Conclusion: The interactive self-ligating brackets show more efficiency in Rate of Retraction, Amount of Incisor movement and Amount of Anchor loss when compared with the conventional brackets. PMID:27307660

  10. Chemical syntheses of inhibitory substrates of the RNA-RNA ligation reaction catalyzed by the hairpin ribozyme.

    PubMed

    Massey, Archna P; Sigurdsson, Snorri Th

    2004-01-01

    The chemical syntheses of RNA oligomers containing modifications on the 5'-carbon of the 5'-terminal nucleoside for crystallographic and mechanistic studies of the hairpin ribozyme are reported. Phosphoramidites 4 and 8 were prepared and used in solid phase syntheses of RNA oligomers containing the sequence 5'-N'UCCUCUCC, where N' indicates either 5'-chloro-5'-deoxyguanosine or 5'-amino-5'-deoxyguanosine, respectively. A ribozyme ligation assay with the 5'-chloro- and 5'-amino-modified RNA oligomers demonstrated their inhibition of the hairpin-catalyzed RNA-RNA ligation reaction.

  11. Toward Homogeneous Erythropoietin: Chemical Synthesis of the Ala1-Gly28 Glycopeptide Domain by “Alanine” Ligation

    PubMed Central

    Kan, Cindy; Trzupek, John D.; Wu, Bin; Wan, Qian; Chen, Gong; Tan, Zhongping; Yuan, Yu; Danishefsky, Samuel J.

    2009-01-01

    The Ala1—Gly28 glycopeptide fragment (28) of EPO was prepared by chemical synthesis as a single glycoform. Key steps in the synthesis include attachment of a complex dodecasaccharide (7) to a seven amino acid peptide via Lansbury aspartylation, native chemical ligation to join peptide 19 with the glycopeptide domain 18, and a selective desulfurization at the ligation site to reveal the natural Ala19. This glycopeptide fragment (28) contains both the requisite N-linked dodecasaccharide and a C-terminal αthioester handle, the latter feature permitting direct coupling with a glycopeptide fragment bearing N-terminal Cys29 without further functionalization. PMID:19334679

  12. Application of meta- and para-Phenylenediamine as Enhanced Oxime Ligation Catalysts for Protein Labeling, PEGylation, Immobilization, and Release.

    PubMed

    Mahmoodi, Mohammad M; Rashidian, Mohammad; Zhang, Yi; Distefano, Mark D

    2015-02-02

    Meta- and para-phenylenediamines have recently been shown to catalyze oxime and hydrazone ligation reactions at rates much faster than aniline, a commonly used catalyst. Here, we demonstrate how these new catalysts can be used in a generally applicable procedure for fluorescent labeling, PEGylation, immobilization, and release of aldehyde- and ketone- functionalized proteins. The chemical orthogonality of phenylenediamine-catalyzed oxime ligation versus copper-catalyzed click reaction has also been harnessed for simultaneous dual labeling of bifunctional proteins containing both aldehyde and alkyne groups in high yield.

  13. Increased secretion of insulin and proliferation of islet {beta}-cells in rats with mesenteric lymph duct ligation

    SciTech Connect

    Nagino, Ko; Yokozawa, Junji; Sasaki, Yu; Matsuda, Akiko; Takeda, Hiroaki; Kawata, Sumio

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Insulin secretion was increased during the OGTT or IVGTT in mesenteric lymph duct-ligated rats. Black-Right-Pointing-Pointer Proliferation of islet {beta}-cells was upregulated in lymph duct-ligated rats. Black-Right-Pointing-Pointer Mesenteric lymph duct flow has a role in glucose metabolism. -- Abstract: Background and aims: It has been suggested that intestinal lymph flow plays an important role in insulin secretion and glucose metabolism after meals. In this study, we investigated the influence of ligation of the mesenteric lymph duct on glucose metabolism and islet {beta}-cells in rats. Methods: Male Sprague-Dawley rats (10 weeks old) were divided into two groups: one underwent ligation of the mesenteric lymph duct above the cistern (ligation group), and the other underwent a sham operation (sham group). After 1 and 2 weeks, fasting plasma concentrations of glucose, insulin, triglyceride, glucose-dependent insulinotropic polypeptide (GIP), and the active form of glucagon-like peptide-1 (GLP-1) were measured. At 2 weeks after the operation, the oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT) were performed. After the rats had been sacrificed, the insulin content of the pancreas was measured and the proliferation of {beta}-cells was assessed immunohistochemically using antibodies against insulin and Ki-67. Results: During the OGTT, the ligation group showed a significant decrease in the plasma glucose concentration at 120 min (p < 0.05) and a significant increase in the plasma insulin concentration by more than 2-fold at 15 min (p < 0.01). On the other hand, the plasma GIP concentration was significantly decreased at 60 min (p < 0.01) in the ligated group, while the active form of GLP-1 showed a significantly higher level at 90 min (1.7-fold; p < 0.05) and 120 min (2.5-fold; p < 0.01). During the IVGTT, the plasma insulin concentration in the ligation group was significantly higher at 2

  14. Electronic Principles Governing the Stability and Reactivity of Ligated Metal and Silicon Encapsulated Transition Metal Clusters

    NASA Astrophysics Data System (ADS)

    Abreu, Marissa Baddick

    A thorough understanding of the underlying electronic principles guiding the stability and reactivity of clusters has direct implications for the identification of stable clusters for incorporation into clusters-assembled materials with tunable properties. This work explores the electronic principles governing the stability and reactivity of two types of clusters: ligated metal clusters and silicon encapsulated transition metal clusters. In the first case, the reactivity of iodine-protected aluminum clusters, Al13Ix - (x=0-4) and Al14Iy- (y=0-5), with the protic species methanol was studied. The symmetrical ground states of Al13Ix- showed no reactivity with methanol but reactivity was achieved in a higher energy isomer of Al 13I2- with iodines on adjacent aluminum atoms -- complementary Lewis acid-base active sites were induced on the opposite side of the cluster capable of breaking the O-H bond in methanol. Al 14Iy- (y=2-5) react with methanol, but only at the ligated adatom site. Reaction of methanol with Al14 - and Al14I- showed that ligation of the adatom was necessary for the reaction to occur there -- revealing the concept of a ligand-activated adatom. In the second case, the study focused heavily on CrSi12, a silicon encapsulated transition metal cluster whose stability and the reason for that stability has been debated heavily in the literature. Calculations of the energetic properties of CrSi n (n=6-16) revealed both CrSi12 and CrSi14 to have enhanced stability relative to other clusters; however CrSi12 lacks all the traditional markers of a magic cluster. Molecular orbital analysis of each of these clusters showed the CNFEG model to be inadequate in describing their stability. Because the 3dz2 orbital of Cr is unfilled in CrSi12, this cluster has only 16 effective valence electrons, meaning that the 18-electron rule is not applicable. The moderate stability of CrSi 12 can be accounted for by the crystal-field splitting of the 3d orbitals, which pushes the

  15. Cationic Gold Clusters Ligated with Differently Substituted Phosphines: Effect of Substitution on Ligand Reactivity and Binding

    SciTech Connect

    Johnson, Grant E.; Olivares, Astrid M.; Hill, David E.; Laskin, Julia

    2015-01-01

    We present a systematic study of the effect of the number of methyl (Me) and cyclohexyl (Cy) functional groups in monodentate phosphine ligands on the solution-phase synthesis of ligated sub-nanometer gold clusters and their gas-phase fragmentation pathways. Small mixed ligand cationic gold clusters were synthesized using ligand exchange reactions between pre-formed triphenylphosphine ligated (PPh3) gold clusters and monodentate Me- and Cy-substituted ligands in solution and characterized using electrospray ionization mass spectrometry (ESI-MS) and collision-induced dissociation (CID) experiments. Under the same experimental conditions, larger gold-PPh3 clusters undergo efficient exchange of unsubstituted PPh3 ligands for singly Me- and Cy-substituted PPh2Me and PPh2Cy ligands. The efficiency of ligand exchange decreases with an increasing number of Me or Cy groups in the substituted phosphine ligands. CID experiments performed for a series of ligand-exchanged gold clusters indicate that loss of a neutral Me-substituted ligand is preferred over loss of a neutral PPh¬3 ligand while the opposite trend is observed for Cy-substituted ligands. The branching ratio of the competing ligand loss channels is strongly correlated with the electron donating ability of the phosphorous lone pair as determined by the relative proton affinity of the ligand. The results indicate that the relative ligand binding energies increase in the order PMe3 < PPhMe2 < PPh2Me < PPh3< PPh2Cy < PPhCy2< PCy3. Furthermore, the difference in relative ligand binding energies increases with the number of substituted PPh3-mMem or PPh3-mCym ligands (L) exchanged onto each cluster. This study provides the first experimental determination of the relative binding energies of ligated gold clusters containing differently substituted monophosphine ligands, which are important to controlling their synthesis and reactivity in solution. The results also indicate that ligand substitution is an important

  16. In-vivo assessment of DNA ligation efficiency and fidelity in cells from patients with Fanconi's anemia and other cancer-prone hereditary disorders.

    PubMed

    Rünger, T M; Sobotta, P; Dekant, B; Möller, K; Bauer, C; Kraemer, K H

    1993-04-01

    We developed a host cell DNA ligation assay, in which we transfected linearized plasmid pZ189 into human lymphoblasts or fibroblasts in order to assess the efficiency and accuracy of DNA ligation within these host cells. We used cell lines from patients with Fanconi's anemia and other chromosome breakage or instability syndromes (Bloom's syndrome, ataxia telangiectasia, Werner's syndrome). With the Fanconi's anemia lymphoblast line GM8010 we did not find a reduced, but a slightly hypermutable DNA ligation. Mutation analysis revealed a unique 7.9-12.5-fold increase in insertions or complex mutations. With cells from the other chromosome breakage/instability syndromes we also found a hypermutable and/or reduced DNA ligation. An impaired DNA ligation might be a common molecular mechanism of genetic instability in these disorders.

  17. The dawn of the RNA World: Toward functional complexity through ligation of random RNA oligomers

    PubMed Central

    Briones, Carlos; Stich, Michael; Manrubia, Susanna C.

    2009-01-01

    A main unsolved problem in the RNA World scenario for the origin of life is how a template-dependent RNA polymerase ribozyme emerged from short RNA oligomers obtained by random polymerization on mineral surfaces. A number of computational studies have shown that the structural repertoire yielded by that process is dominated by topologically simple structures, notably hairpin-like ones. A fraction of these could display RNA ligase activity and catalyze the assembly of larger, eventually functional RNA molecules retaining their previous modular structure: molecular complexity increases but template replication is absent. This allows us to build up a stepwise model of ligation-based, modular evolution that could pave the way to the emergence of a ribozyme with RNA replicase activity, step at which information-driven Darwinian evolution would be triggered. PMID:19318464

  18. Effect of Tridax procumbens (Linn.) on bile duct ligation-induced liver fibrosis in rats.

    PubMed

    Joshi, P P; Patil, S D; Silawat, N; Deshmukh, P T

    2011-12-01

    The present study was undertaken to clarify whether methanolic extract of Tridax procumbens prevents liver fibrosis in rat. The hepatic fibrosis was induced by 28 days of bile duct ligation in rats. The 4-week treatment with Tridex procumbens reduced the serum aspartate aminotransferase (U L⁻¹), glutamate pyruvate transaminase (U L⁻¹), alkaline phosphatase (IU L⁻¹), lactate dehydrogenase (IU L⁻¹), total bilirubin (mg dL⁻¹), direct bilirubin (mg dL⁻¹) and hydroxyproline (mg gm⁻¹) content in liver and improved the histological appearance of liver section. The results of this study led us to conclude that T. procumbens can reduce the degree of hepatocellular damage and may become antifibrotic agent for liver fibrosis.

  19. Highly specific and sensitive electrochemical genotyping via gap ligation reaction and surface hybridization detection.

    PubMed

    Huang, Yong; Zhang, Yan-Li; Xu, Xiangmin; Jiang, Jian-Hui; Shen, Guo-Li; Yu, Ru-Qin

    2009-02-25

    This paper developed a novel electrochemical genotyping strategy based on gap ligation reaction with surface hybridization detection. This strategy utilized homogeneous enzymatic reactions to generate molecular beacon-structured allele-specific products that could be cooperatively annealed to capture probes stably immobilized on the surface via disulfide anchors, thus allowing ultrasensitive surface hybridization detection of the allele-specific products through redox tags in close proximity to the electrode. Such a unique biphasic architecture provided a universal methodology for incorporating enzymatic discrimination reactions in electrochemical genotyping with desirable reproducibility, high efficiency and no interferences from interficial steric hindrance. The developed technique was demonstrated to show intrinsic high sensitivity for direct genomic analysis, and excellent specificity with discriminativity of single nucleotide variations.

  20. Photoclick chemistry: a fluorogenic light-triggered in vivo ligation reaction.

    PubMed

    Ramil, Carlo P; Lin, Qing

    2014-08-01

    The ability to use chemical reactivity to monitor and control biomolecular processes with a spatial and temporal precision motivated the development of light-triggered in vivo chemistries. To this end, the photoinduced tetrazole-alkene cycloaddition, also termed 'photoclick chemistry' offers a very rapid chemical ligation platform for the manipulation of biomolecules and matrices in vivo. Here we outline the recent developments in the optimization of this chemistry, ranging from the search for substrates that offer two-photon photoactivatability, superior reaction kinetics, and/or genetic encodability, to the study of the reaction mechanism. The applications of the photoclick chemistry in protein labeling in vitro and in vivo as well as in preparing 'smart' hydrogels for 3D cell culture are highlighted.

  1. Simultaneous detection of DNA from 10 food allergens by ligation-dependent probe amplification.

    PubMed

    Ehlert, Alexandra; Demmel, Anja; Hupfer, Christine; Busch, Ulrich; Engel, Karl-Heinz

    2009-04-01

    The simultaneous detection of DNA from different allergenic food ingredients by a ligation-dependent probe amplification (LPA) system is described. The approach allows detection of several targets in a one-tube assay. Synthetic oligonucleotides were designed to detect DNA from peanuts, cashews, pecans, pistachios, hazelnuts, sesame seeds, macadamia nuts, almonds, walnuts and brazil nuts. The specificity of the system was tested with DNA from more than 50 plant and animal species. The sensitivity of the method was suitable to detect allergenic ingredients in the low mg kg(-1) range. The limit of detection (LOD) for single allergens in different food matrices was 5 mg kg(-1). The novel analytical strategy represents a useful tool for the surveillance of established legislation on food allergens within the European Union.

  2. Initial experience with proximal ligation for profunda femoris artery aneurysms: report of three cases.

    PubMed

    Shintani, Tsunehiro; Norimatsu, Togo; Atsuta, Koji; Saitou, Takaaki; Higashi, Shigeki; Mitsuoka, Hiroshi

    2014-04-01

    Profunda femoris artery aneurysms (PFAAs) are rare and difficult to diagnose in the early stage. They are often found due to the presence of complicated conditions, such as rapid expansion, rupture, or acute lower limb ischemia. Surgical procedures such as aneurysmectomy and endoaneurysmorrhaphy tend to be technically challenging because of the patient status and the extent of the aneurysm. We experienced three cases of PFAAs that were treated by proximal ligation (PL) without complete control of the distal branches. The exclusion of PFAAs was confirmed by duplex ultrasound or angiography at the end of the operation. There was no mortality in the perioperative period. During a 12-month follow-up, all cases exhibited complete exclusion of aneurysms with marked size reduction. Based on these findings, we propose that PL, with a careful follow-up for PFAA exclusion and distal limb circulation, could be an alternative treatment for complicated PFAAs.

  3. High-throughput cloning, expression and purification of glycoside hydrolases using Ligation-Independent Cloning (LIC).

    PubMed

    Camilo, Cesar M; Polikarpov, Igor

    2014-07-01

    Recent advances in DNA sequencing techniques have led to an explosion in the amount of available genome sequencing data and this provided an inexhaustible source of uncharacterized glycoside hydrolases (GH) to be studied both structurally and enzymatically. Ligation-Independent Cloning (LIC), an interesting alternative to traditional, restriction enzyme-based cloning, and commercial recombinatorial cloning, was adopted and optimized successfully for a high throughput cloning, expression and purification pipeline. Using this platform, 130 genes encoding mainly uncharacterized glycoside hydrolases from 13 different organisms were cloned and submitted to a semi-automated protein expression and solubility screening in Escherichia coli, resulting in 73 soluble targets. The high throughput approach proved to be a powerful tool for production of recombinant glycoside hydrolases for further structural and biochemical characterization and confirmed that thioredoxin fusion tag (TRX) is a better choice to increase solubility of recombinant glycoside hydrolases expressed in E. coli, when compared to His-tag alone.

  4. Live-Cell Labeling of Specific Protein Glycoforms by Proximity-Enhanced Bioorthogonal Ligation

    PubMed Central

    Robinson, Peter V.; de Almeida-Escobedo, Gabriela; de Groot, Amber E.; McKechnie, Julia L.

    2016-01-01

    Reagents for detecting post-translational modifications in the context of their protein scaffold are powerful tools, but are challenging to develop for glycosylated epitopes. We describe a strategy for detecting protein-specific glycosylation through the use of cyclooctyne-aptamer conjugates. These molecules selectively ligate to azidosugar-labeled glycans exclusively on a target protein on live cells. We characterized aptamer conjugates against two different cell surface glycoproteins and show that these reagents are amenable to detecting protein sialoforms by mass spectrometry, Western blotting, and flow cytometry. Given the abundance of aptamers that bind cell surface targets, we expect this technology will be a useful platform for investigating the roles of protein-specific glycosylation in various cellular contexts. PMID:26280358

  5. Catalytic dehydroaromatization of n-alkanes by pincer-ligated iridium complexes

    NASA Astrophysics Data System (ADS)

    Ahuja, Ritu; Punji, Benudhar; Findlater, Michael; Supplee, Carolyn; Schinski, William; Brookhart, Maurice; Goldman, Alan S.

    2011-02-01

    Aromatic hydrocarbons are among the most important building blocks in the chemical industry. Benzene, toluene and xylenes are obtained from the high temperature thermolysis of alkanes. Higher alkylaromatics are generally derived from arene-olefin coupling, which gives branched products—that is, secondary alkyl arenes—with olefins higher than ethylene. The dehydrogenation of acyclic alkanes to give alkylaromatics can be achieved using heterogeneous catalysts at high temperatures, but with low yields and low selectivity. We present here the first catalytic conversion of n-alkanes to alkylaromatics using homogeneous or molecular catalysts—specifically ‘pincer’-ligated iridium complexes—and olefinic hydrogen acceptors. For example, the reaction of n-octane affords up to 86% yield of aromatic product, primarily o-xylene and secondarily ethylbenzene. In the case of n-decane and n-dodecane, the resulting alkylarenes are exclusively unbranched (that is, n-alkyl-substituted), with selectivity for the corresponding o-(n-alkyl)toluene.

  6. Rapid construction of mycobacterial mutagenesis vectors using ligation-independent cloning

    PubMed Central

    Balhana, Ricardo; Stoker, Neil G.; Sikder, Mahmudul Hasan; Chauviac, Francois-Xavier; Kendall, Sharon L.

    2010-01-01

    Targeted mutagenesis is one of the major tools for determining the function of a given gene and its involvement in bacterial pathogenesis. In mycobacteria, gene deletion is often accomplished by using allelic exchange techniques that commonly utilise a suicide delivery vector. We have adapted a widely-used suicide delivery vector (p1NIL) for cloning two flanking regions of a gene using ligation independent cloning (LIC). The pNILRB plasmid series produced allow a faster, more efficient and less laborious cloning procedure. In this paper we describe the making of pNILRB5, a modified version of p1NIL that contains two pairs of LIC sites flanking either a sacB or a lacZ gene. We demonstrate the success of this technique by generating 3 mycobacterial mutant strains. These vectors will contribute to more high-throughput methods of mutagenesis. PMID:20650290

  7. A thiolate-ligated nonheme oxoiron(IV) complex relevant to cytochrome P450.

    PubMed

    Bukowski, Michael R; Koehntop, Kevin D; Stubna, Audria; Bominaar, Emile L; Halfen, Jason A; Münck, Eckard; Nam, Wonwoo; Que, Lawrence

    2005-11-11

    Thiolate-ligated oxoiron(IV) centers are postulated to be the key oxidants in the catalytic cycles of oxygen-activating cytochrome P450 and related enzymes. Despite considerable synthetic efforts, chemists have not succeeded in preparing an appropriate model complex. Here we report the synthesis and spectroscopic characterization of [FeIV(O)(TMCS)]+ where TMCS is a pentadentate ligand that provides a square pyramidal N4(SR)apical, where SR is thiolate, ligand environment about the iron center, which is similar to that of cytochrome P450. The rigidity of the ligand framework stabilizes the thiolate in an oxidizing environment. Reactivity studies suggest that thiolate coordination favors hydrogen-atom abstraction chemistry over oxygen-atom transfer pathways in the presence of reducing substrates.

  8. The rationale, evolution and clinical application of the self-ligating bracket.

    PubMed

    Damon, D H

    1998-08-01

    There is ample evidence in the literature that conventional orthodontic mechanics while intended to move teeth efficiently rarely achieve atraumatic remodeling of periodontal tissues. The vascular supply is often interrupted, which in turn affects the oxidative metabolism. Moreover, teeth splinted in groups do not appear to move as efficiently as single teeth. The novel bracket design and treatment regimen described in this report allow teeth to move individually, yet stay within a group. The self-ligating bracket design allows for rapid leveling because teeth drift along the path of least resistance with little or no friction between the bracket and slot of the wire. The hinge mechanism eliminates much of the friction created by the conventional wire or latex ties used to secure the archwire in the bracket slot. Thus, sliding mechanics is achieved in the true sense of the word. This system is capable of increasing the appointment intervals, and possibly reducing the overall treatment time.

  9. Oxidized nucleotide insertion by pol β confounds ligation during base excision repair

    PubMed Central

    Çağlayan, Melike; Horton, Julie K.; Dai, Da-Peng; Stefanick, Donna F.; Wilson, Samuel H.

    2017-01-01

    Oxidative stress in cells can lead to accumulation of reactive oxygen species and oxidation of DNA precursors. Oxidized purine nucleotides can be inserted into DNA during replication and repair. The main pathway for correcting oxidized bases in DNA is base excision repair (BER), and in vertebrates DNA polymerase β (pol β) provides gap filling and tailoring functions. Here we report that the DNA ligation step of BER is compromised after pol β insertion of oxidized purine nucleotides into the BER intermediate in vitro. These results suggest the possibility that BER mediated toxic strand breaks are produced in cells under oxidative stress conditions. We observe enhanced cytotoxicity in oxidizing-agent treated pol β expressing mouse fibroblasts, suggesting formation of DNA strand breaks under these treatment conditions. Increased cytotoxicity following MTH1 knockout or treatment with MTH1 inhibitor suggests the oxidation of precursor nucleotides. PMID:28067232

  10. Gas-phase activation of methane by ligated transition-metal cations

    PubMed Central

    Schröder, Detlef; Schwarz, Helmut

    2008-01-01

    Motivated by the search for ways of a more efficient usage of the large, unexploited resources of methane, recent progress in the gas-phase activation of methane by ligated transition-metal ions is discussed. Mass spectrometric experiments demonstrate that the ligands can crucially influence both reactivity and selectivity of transition-metal cations in bond-activation processes, and the most reactive species derive from combinations of transition metals with the electronegative elements fluorine, oxygen, and chlorine. Furthermore, the collected knowledge about intramolecular kinetic isotope effects associated with the activation of C–H(D) bonds of methane can be used to distinguish the nature of the bond activation as a mere hydrogen-abstraction, a metal-assisted mechanism or more complex reactions such as formation of insertion intermediates or σ-bond metathesis. PMID:18955709

  11. Multiplex ligation-dependent probe amplification: a novel approach for genetic diagnosis of Porphyria.

    PubMed

    Di Pierro, Elena; Brancaleoni, Valentina; Besana, Valeria; Cappellini, Maria Domenica

    2009-08-01

    Porphyrias are disorders caused by the genetic defects of enzymes of the heme pathway and are characterized by such a wide genetic heterogeneity that even the molecular analysis is not always decisive for a correct diagnosis. In the past few years, deletion with a size range of few kilobase pairs have been reported. These peculiar mutations, missed by both sequencing and cytogenetic techniques, have been identified by time consuming and technically demanding methods. To provide a rapid and sensitive method for the detection of deletions responsible for porphyria, we successfully designed and tested seven chemically synthesized probe sets specific for each heme gene and their flanking regions, to be used in multiplex ligation-dependent probe amplification technique.

  12. Investigation toward multi-epitope vaccine candidates using native chemical ligation.

    PubMed

    Fujita, Yoshio; Moyle, Peter M; Hieu, Suzanne; Simerska, Pavla; Toth, Istvan

    2008-01-01

    We applied native chemical ligation (NCL) method to the synthesis of highly pure lipid-core peptide (LCP) vaccines to attach various peptide epitopes. In the case of the synthesis of LCP vaccine with two different peptide epitopes, LCP moieties having two free Cys and two protected Cys derivatives (S-acetamidemethyl-Cys, (Cys(Acm)), N-methylsulfonylethyloxycarbonyl-Cys (Msc-Cys), or 1,3-thiazolidine-4-carboxylic acid (Thz)) on oligolysine branches were prepared in order to couple two different epitopes by stepwise NCL. It was found that the difficulty in NCL of first two peptide antigen was associated with the steric hindrance. Using Thz instead of Cys(Acm) and Msc-Cys was important to reduce the steric hindrance and improve NCL yield.

  13. Testing the feasibility of DNA typing for human identification by PCR and an oligonucleotide ligation assay.

    PubMed Central

    Delahunty, C.; Ankener, W.; Deng, Q.; Eng, J.; Nickerson, D. A.

    1996-01-01

    The use of DNA typing in human genome analysis is increasing and finding widespread application in the area of forensic and paternity testing. In this report, we explore the feasibility of typing single nucleotide polymorphisms (SNPs) by using a semiautomated method for analyzing human DNA samples. In this approach, PCR is used to amplify segments of human DNA containing a common SNP. Allelic nucleotides in the amplified product are then typed by a colorimetric implementation of the oligonucleotide ligation assay (OLA). The results of the combined assay, PCR/OLA, are read directly by a spectrophotometer; the absorbances are compiled; and the genotypes are automatically determined. A panel of 20 markers has been developed for DNA typing and has been tested using a sample panel from the CEPH pedigrees (CEPH parents). The results of this typing, as well as the potential to apply this method to larger populations, are discussed. Images Figure 2 PMID:8651301

  14. Testing the feasibility of DNA typing for human identification by PCR and an oligonucleotide ligation assay

    SciTech Connect

    Delahunty, C.; Ankener, W.; Deng, Qiang

    1996-06-01

    The use of DNA typing in human genome analysis is increasing and finding widespread application in the area of forensic and paternity testing. In this report, we explore the feasibility of typing single nucleotide polymorphisms (SNPs) by using a semiautomated method for analyzing human DNA samples. In this approach, PCR is used to amplify segments of human DNA containing a common SNP. Allelic nucleotides in the amplified product are then typed by a calorimetric implementation of the oligonucleotide ligation assay (OLA). The results of the combined assay, PCR/OLA, are read directly by a spectrophotometer; the absorbances are compiled and the genotypes are automatically determined. A panel of 20 markers has been developed for DNA typing and has been tested using a sample panel from the CEPH pedigrees (CEPH parents). The results of this typing, as well as the potential to apply this method to larger populations, are discussed. 62 refs., 2 figs., 4 tabs.

  15. Scaffolded multiple cyclic peptide libraries for protein mimics by native chemical ligation.

    PubMed

    van de Langemheen, H; van Hoeke, M; Quarles van Ufford, H C; Kruijtzer, J A W; Liskamp, R M J

    2014-07-07

    The accessibility to collections, libraries and arrays of cyclic peptides is increasingly important since cyclic peptides may provide better mimics of the loop-like structures ubiquitously present in and - especially - on the surface of proteins. The next important step is the preparation of libraries of ensembles of scaffolded cyclic peptides, which upon screening may lead to promising protein mimics. Here we describe the synthesis of a tri-cysteine containing scaffold as well as the simultaneous native chemical ligation of three cyclic peptides thereby affording a clean library of multiple cyclic peptides on this scaffold, representing potential mimics of gp120. Members of this collection of protein mimics showed a decent inhibition of the gp120-CD4 interaction.

  16. ECM-incorporated hydrogels cross-linked via native chemical ligation to engineer stem cell microenvironments.

    PubMed

    Jung, Jangwook P; Sprangers, Anthony J; Byce, John R; Su, Jing; Squirrell, Jayne M; Messersmith, Phillip B; Eliceiri, Kevin W; Ogle, Brenda M

    2013-09-09

    Limiting the precise study of the biochemical impact of whole molecule extracellular matrix (ECM) proteins on stem cell differentiation is the lack of 3D in vitro models that can accommodate many different types of ECM. Here we sought to generate such a system while maintaining consistent mechanical properties and supporting stem cell survival. To this end, we used native chemical ligation to cross-link poly(ethylene glycol) macromonomers under mild conditions while entrapping ECM proteins (termed ECM composites) and stem cells. Sufficiently low concentrations of ECM were used to maintain constant storage moduli and pore size. Viability of stem cells in composites was maintained over multiple weeks. ECM of composites encompassed stem cells and directed the formation of distinct structures dependent on ECM type. Thus, we introduce a powerful approach to study the biochemical impact of multiple ECM proteins (either alone or in combination) on stem cell behavior.

  17. [Ligation of the left coronary artery ostium in its origin from the pulmonary trunk].

    PubMed

    Fal'kovskiĭ, G E; Aleksi-Meskhishvili, V V; Berishvili, I I

    1980-02-01

    Operation was performed on 8 patients whose left coronary artery arose from the pulmonary artery; one of the patients was operated on twice. Three patients had been operated on twice before 1972, the operation in all of them consisted in talcum suspension insufflation into the pericardium. The results of these operations were poor. Operation for ligation of the orifice of the left coronary artery was conducted on 6 patients (including one with the ineffective talcum suspension insufflation into the pericardium). All patients who were operated on at the age of over one year survived. In children of the first year of life with a low ejection fraction and absence of expulsion on the level of the pulmonary artery the results of surgery were poor.

  18. Assessing long-distance RNA sequence connectivity via RNA-templated DNA–DNA ligation

    PubMed Central

    Roy, Christian K; Olson, Sara; Graveley, Brenton R; Zamore, Phillip D; Moore, Melissa J

    2015-01-01

    Many RNAs, including pre-mRNAs and long non-coding RNAs, can be thousands of nucleotides long and undergo complex post-transcriptional processing. Multiple sites of alternative splicing within a single gene exponentially increase the number of possible spliced isoforms, with most human genes currently estimated to express at least ten. To understand the mechanisms underlying these complex isoform expression patterns, methods are needed that faithfully maintain long-range exon connectivity information in individual RNA molecules. In this study, we describe SeqZip, a methodology that uses RNA-templated DNA–DNA ligation to retain and compress connectivity between distant sequences within single RNA molecules. Using this assay, we test proposed coordination between distant sites of alternative exon utilization in mouse Fn1, and we characterize the extraordinary exon diversity of Drosophila melanogaster Dscam1. DOI: http://dx.doi.org/10.7554/eLife.03700.001 PMID:25866926

  19. Incorporation of azides into recombinant proteins for chemoselective modification by the Staudinger ligation

    PubMed Central

    Kiick, Kristi L.; Saxon, Eliana; Tirrell, David A.; Bertozzi, Carolyn R.

    2002-01-01

    The introduction of chemically unique groups into proteins by means of non-natural amino acids has numerous applications in protein engineering and functional studies. One method to achieve this involves the utilization of a non-natural amino acid by the cell's native translational apparatus. Here we demonstrate that a methionine surrogate, azidohomoalanine, is activated by the methionyl-tRNA synthetase of Escherichia coli and replaces methionine in proteins expressed in methionine-depleted bacterial cultures. We further show that proteins containing azidohomoalanine can be selectively modified in the presence of other cellular proteins by means of Staudinger ligation with triarylphosphine reagents. Incorporation of azide-functionalized amino acids into proteins in vivo provides opportunities for protein modification under native conditions and selective labeling of proteins in the intracellular environment. PMID:11752401

  20. Peptide Conjugation to a Polymer Coating via Native Chemical Ligation of Azlactones for Cell Culture.

    PubMed

    Schmitt, Samantha K; Trebatoski, David J; Krutty, John D; Xie, Angela W; Rollins, Benjamin; Murphy, William L; Gopalan, Padma

    2016-03-14

    Conjugation of biomolecules for stable presentation is an essential step toward reliable chemically defined platforms for cell culture studies. In this work, we describe the formation of a stable and site-specific amide bond via the coupling of a cysteine terminated peptide at low concentration to an azlactone containing copolymer coating. A copolymer of polyethylene glycol methyl ether methacrylate-ran-vinyl azlactone-ran-glycidyl methacrylate P(PEGMEMA-r-VDM-r-GMA) was used to form a thin coating (20-30 nm) on silicon and polycarbonate substrates. The formation and stability of coating-peptide bonds for peptides containing free thiols and amines were quantified by X-ray photoelectron spectroscopy (XPS) after exposure to cell culture conditions. Peptides containing a thiol as the only nucleophile coupled via a thioester bond; however, the bond was labile under cell culture conditions and almost all the bound peptides were displaced from the surface over a period of 2 days. Coupling with N-terminal primary amine peptides resulted in the formation of an amide bond with low efficiency (<20%). In contrast, peptides containing an N-terminal cysteine, which contain both nucleophiles (free thiol and amine) in close proximity, bound with 67% efficiency under neutral pH, and were stable under the same conditions for 2 weeks. Control studies confirm that the stable amide formation was a result of an intramolecular rearrangement through a N-acyl intermediate that resembles native chemical ligation. Through a combination of XPS and cell culture studies, we show that the cysteine terminated peptides undergo a native chemical ligation process at low peptide concentration in aqueous media, short reaction time, and at room temperature resulting in the stable presentation of peptides beyond 2 weeks for cell culture studies.

  1. Detection of human papillomaviruses by polymerase chain reaction and ligation reaction on universal microarray.

    PubMed

    Ritari, Jarmo; Hultman, Jenni; Fingerroos, Rita; Tarkkanen, Jussi; Pullat, Janne; Paulin, Lars; Kivi, Niina; Auvinen, Petri; Auvinen, Eeva

    2012-01-01

    Sensitive and specific detection of human papillomaviruses (HPV) in cervical samples is a useful tool for the early diagnosis of epithelial neoplasia and anogenital lesions. Recent studies support the feasibility of HPV DNA testing instead of cytology (Pap smear) as a primary test in population screening for cervical cancer. This is likely to be an option in the near future in many countries, and it would increase the efficiency of screening for cervical abnormalities. We present here a microarray test for the detection and typing of 15 most important high-risk HPV types and two low risk types. The method is based on type specific multiplex PCR amplification of the L1 viral genomic region followed by ligation detection reaction where two specific ssDNA probes, one containing a fluorescent label and the other a flanking ZipCode sequence, are joined by enzymatic ligation in the presence of the correct HPV PCR product. Human beta-globin is amplified in the same reaction to control for sample quality and adequacy. The genotyping capacity of our approach was evaluated against Linear Array test using cervical samples collected in transport medium. Altogether 14 out of 15 valid samples (93%) gave concordant results between our test and Linear Array. One sample was HPV56 positive in our test and high-risk positive in Hybrid Capture 2 but remained negative in Linear Array. The preliminary results suggest that our test has accurate multiple HPV genotyping capability with the additional advantages of generic detection format, and potential for high-throughput screening.

  2. Cecal Ligation and Puncture Results in Long-Term Central Nervous System Myeloid Inflammation

    PubMed Central

    Singer, Benjamin H.; Newstead, Michael W.; Zeng, Xianying; Cooke, Christopher L.; Thompson, Robert C.; Singer, Kanakadurga; Ghantasala, Ramya; Parent, Jack M.; Murphy, Geoffrey G.; Iwashyna, Theodore J.; Standiford, Theodore J.

    2016-01-01

    Survivors of sepsis often experience long-term cognitive and functional decline. Previous studies utilizing lipopolysaccharide injection and cecal ligation and puncture in rodent models of sepsis have demonstrated changes in depressive-like behavior and learning and memory after sepsis, as well as evidence of myeloid inflammation and cytokine expression in the brain, but the long-term course of neuroinflammation after sepsis remains unclear. Here, we utilize cecal ligation and puncture with greater than 80% survival as a model of sepsis. We found that sepsis survivor mice demonstrate deficits in extinction of conditioned fear, but no acquisition of fear conditioning, nearly two months after sepsis. These cognitive changes occur in the absence of neuronal loss or changes in synaptic density in the hippocampus. Sepsis also resulted in infiltration of monocytes and neutrophils into the CNS at least two weeks after sepsis in a CCR2 independent manner. Cellular inflammation is accompanied by long-term expression of pro-inflammatory cytokine and chemokine genes, including TNFα and CCR2 ligands, in whole brain homogenates. Gene expression analysis of microglia revealed that while microglia do express anti-microbial genes and damage-associated molecular pattern molecules of the S100A family of genes at least 2 weeks after sepsis, they do not express the cytokines observed in whole brain homogenates. Our results indicate that in a naturalistic model of infection, sepsis results in long-term neuroinflammation, and that this sustained inflammation is likely due to interactions among multiple cell types, including resident microglia and peripherally derived myeloid cells. PMID:26862765

  3. Intrahepatic Left to Right Portoportal Venous Collateral Vascular Formation in Patients Undergoing Right Portal Vein Ligation

    SciTech Connect

    Lienden, K. P. van; Hoekstra, L. T.; Bennink, R. J.; Gulik, T. M. van

    2013-12-15

    Purpose: We investigated intrahepatic vascular changes in patients undergoing right portal vein ligation (PVL) or portal vein embolization (PVE) in conjunction with the ensuing hypertrophic response and function of the left liver lobe. Methods: Between December 2008 and October 2011, 7 patients underwent right PVL and 14 patients PVE. Computed tomographic (CT) volumetry to assess future remnant liver (FRL) and functional hepatobiliary scintigraphy were performed in all patients before and 3 weeks after portal vein occlusion. In 18 patients an intraoperative portography was performed to assess perfusion through the occluded portal branches. Results: In all patients after initially successful PVL, reperfused portal veins were observed on CT scan 3 weeks after portal occlusion. This was confirmed in all cases during intraoperative portography. Intrahepatic portoportal collaterals were identified in all patients in the PVL group and in one patient in the PVE group. In all other PVE patients, complete occlusion of the embolized portal branches was observed on CT scan and on intraoperative portography. The median increase of FRL volume after PVE was 41.6 % (range 10-305 %), and after PVL was only 8.1 % (range 0-102 %) (p = 0.179). There were no differences in FRL function between both groups. Conclusion: Preoperative PVE and PVL are both methods to induce hypertrophy of the FRL in anticipation of major liver resection. Compared to PVE, PVL seems less efficient in inducing hypertrophy of the nonoccluded left lobe. This could be caused by the formation of intrahepatic portoportal neocollateral vessels, through which the ligated portal branches are reperfused within 3 weeks.

  4. For Better Orchiopexy, Processus Vaginalis Should Be Dissected and a High Ligation Should Be Performed

    PubMed Central

    Sonmez, Kaan; Karabulut, Ramazan; Turkyilmaz, Zafer; Kaya, Cem; Pehlivan, Yildiz; Basaklar, A. Can

    2016-01-01

    Objective Data on the prevalence of patent processus vaginalis (PPV) and hernia in patients with cryptorchidism are controversial. While some pediatric surgeons do not dissect the processus vaginalis (PV), most prefer to do so to prevent hernia formation and to achieve an effective orchiopexy outcome. This study was performed to evaluate the importance of dissection and high ligation of the PV during treatment of undescended testis (UT). Methods The clinical findings and surgical procedures of 55 patients with UT were retrospectively investigated. Results The mean patient age was 2.5 (range 1.0–12.0) years. Non-palpable testis (NPT) was located on the right and left side in 39 and 16 patients, respectively. Ultrasonography revealed no testis in 10 patients and an atrophic testis in 7 patients. Seven patients had a parent with an inguinal hernia, and the silk sign or a PPV was detected during inguinoscrotal examination in 22 patients. Undescended testis repair was performed by an inguinal approach in all patients. The inguinal canal was opened in all patients; 42 patients had a wider-than-normal internal ring (>2.5 cm), and the posterior wall of the inguinal canal was consequently weakened. Two-stage orchiopexy was performed in 2 patients, and 15 underwent the Prentiss maneuver. In the remaining patients, the dissection was easily done, and the orchiopexy was performed without any difficulty. Scrotal edema and wound infection occurred in five and two patients, respectively. One patient presented with an atrophic testis, and three had recurrent UT. Inguinal hernia was not observed in any of the patients during the study period, and all procedures were performed on an outpatient basis. Conclusion High ligation of the PV is an effective method for successful orchiopexy and prevention of inguinal hernia in patients with NPT and UT. PMID:27487307

  5. Ultrasensitive single-nucleotide polymorphism detection using target-recycled ligation, strand displacement and enzymatic amplification

    NASA Astrophysics Data System (ADS)

    Zhang, Yue; Guo, Yuan; Quirke, Philip; Zhou, Dejian

    2013-05-01

    We report herein the development of a highly sensitive and selective approach for label-free DNA detection by combining target-recycled ligation (TRL), magnetic nanoparticle assisted target capture/separation, and efficient enzymatic amplification. We show that our approach can detect as little as 30 amol (600 fM in 50 μL) of unlabelled single-stranded DNA targets and offer an exquisitely high discrimination ratio (up to >380 fold with background correction) between a perfect-match cancer mutant and its single-base mismatch (wild-type) DNA target. Furthermore, it can quantitate the rare cancer mutant (KRAS codon 12) in a large excess of coexisting wild-type DNAs down to 0.75%. This sensor appears to be well-suited for sensitive SNP detection and a wide range of DNA mutation based diagnostic applications.We report herein the development of a highly sensitive and selective approach for label-free DNA detection by combining target-recycled ligation (TRL), magnetic nanoparticle assisted target capture/separation, and efficient enzymatic amplification. We show that our approach can detect as little as 30 amol (600 fM in 50 μL) of unlabelled single-stranded DNA targets and offer an exquisitely high discrimination ratio (up to >380 fold with background correction) between a perfect-match cancer mutant and its single-base mismatch (wild-type) DNA target. Furthermore, it can quantitate the rare cancer mutant (KRAS codon 12) in a large excess of coexisting wild-type DNAs down to 0.75%. This sensor appears to be well-suited for sensitive SNP detection and a wide range of DNA mutation based diagnostic applications. Electronic supplementary information (ESI) available: The preparation, modification and magnetic retrieval of MNPs, optimisation of the Cap-MNP probe and experimental procedures and the SNP discrimination at low target abundance (5 fmol). See DOI: 10.1039/c3nr01010d

  6. Comparison of two preclinical myocardial infarct models: coronary coil deployment versus surgical ligation

    PubMed Central

    2014-01-01

    Background Despite recent advances, myocardial infarction (MI) remains the leading cause of death worldwide. Pre-clinical animal models that closely mimic human MI are pivotal for a quick translation of research and swine have similarities in anatomy and physiology. Here, we compared coronary surgical ligation versus coil embolization MI models in swine. Methods Fifteen animals were randomly distributed to undergo surgical ligation (n = 7) or coil embolization (n = 8). We evaluated infarct size, scar fibrosis, inflammation, myocardial vascularization, and cardiac function by magnetic resonance imaging (MRI). Results Thirty-five days after MI, there were no differences between the models in infarct size (P = 0.53), left ventricular (LV) ejection fraction (P = 0.19), LV end systolic volume (P = 0.22), LV end diastolic volume (P = 0.84), and cardiac output (P = 0.89). Histologically, cardiac scars did not differ and the collagen content, collagen type I (I), collagen type III (III), and the I/III ratio were similar in both groups. Inflammation was assessed using specific anti-CD3 and anti-CD25 antibodies. There was similar activation of inflammation throughout the heart after coil embolization (P = 0.78); while, there were more activated lymphocytes in the infarcted myocardium in the surgical occlusion model (P = 0.02). Less myocardial vascularization in the infarction areas compared with the border and remote zones only in coil embolization animals was observed (P = 0.004 and P = 0.014, respectively). Conclusions Our results support that surgical occlusion and coil embolization MI models generate similar infarct size, cardiac function impairment, and myocardial fibrosis; although, inflammation and myocardial vascularization levels were closer to those found in humans when coil embolization was performed. PMID:24885652

  7. Ligation of intersphincteric fistula tract (LIFT) to treat anal fistula: systematic review and meta-analysis.

    PubMed

    Hong, K D; Kang, S; Kalaskar, S; Wexner, S D

    2014-08-01

    Sphincter-preserving approaches to treat anal fistula do not jeopardize continence; however, healing rates are suboptimal. In this context, ligation of the intersphincteric fistula tract (LIFT) can be considered promising offering high success rates and a relatively simple procedure. This review aimed to investigate the outcomes of LIFT to treat anal fistula. We conducted a systematic review of the Pubmed, Web of Science, and Cochrane databases, to retrieve all relevant scientific original articles and scientific abstracts (Web of Science) related to the LIFT procedure for anal fistula between January 2007 and March 2013. The search yielded 24 original articles including 1,110 patients; these included one randomized controlled study, three case control studies, and 20 case series. Most studies included patients with trans-sphincteric or complex fistula, not amenable to fistulotomy. During a pooled mean 10.3 months of follow-up, the mean success, incontinence, intraoperative, and postoperative complication rates were 76.4, 0, 0, and 5.5%, respectively. A sensitivity analysis showed that the impact on success in terms of follow-up duration, study size, and combining other procedures was limited. There was no association between pre-LIFT drainage seton and success of LIFT. Ligation of the intersphincteric fistula tract appears to be an effective and safe treatment for trans-sphincteric or complex anal fistula. Combining other procedures and a pre-LIFT drainage seton does not seem to confer any added benefit in terms of success. However, given the lack of prospective randomized trials, interpretation of these data must be cautious. Further trials are mandatory to identify predictive factors for success, and true effectiveness of the LIFT compared to other sphincter-preserving procedures to treat anal fistula.

  8. Laparoscopic splenic artery ligation for hypersplenism in cirrhosis: A case series

    PubMed Central

    Nag, Hirdaya H.; Chandrasekar, Sandip; Manipadum, John M.; Vageesh, Bettageri G.

    2016-01-01

    BACKGROUND: Splenectomy for the treatment of hypersplenism in patients with cirrhosis (HIC) is related with complications. Laparoscopic splenic artery ligation (LSAL) may be an alternative treatment option. AIMS: To evaluate safety and feasibility of LSAL in the treatment of HIC. PATIENTS AND METHODS: Retrospective analysis of prospectively collected data of ten patients with HIC who were treated with LSAL from October 2012 to February 2015. RESULTS: The median (range) age was 33.2 (13-56) years and sex distribution was equal. The median (range) leukocyte counts (×109/L) before, and at 3, 6 and 12 months after LSAL were 2.2 (0.8-8.2) and 5.65 (2.78-10.7), 4.7 (2.8-7.8) and 4.95 (3.4-7.7) respectively. The median (range) platelet counts (×109/L) before and at 3, 6 and 12 months after LSAL were 25.5 (11-65) and 75 (39-289), 74 (32-184) and 76 (56-251) respectively. Following LSAL, there was a significant improvement in total leucocyte count, platelet count and Model for End-Stage Liver Disease (MELD) score (P < 0.05). Two patients (20%) developed intraoperative bleeding and required conversion; one of these two patients developed splenic cyst that required radiological intervention. Four patients (40%) had post ligation syndrome (PLS) that was managed conservatively. During a median (range) follow-up of 19.5 (5-29) months, one patient (10%) required splenectomy due to inadequate response. CONCLUSION: LSAL is a safe and feasible treatment option for the palliation of symptomatic HIC, however, further prospective trials are necessary for confirmation. PMID:27251809

  9. Secondary structure and zinc ligation of human recombinant short-form stromelysin by multidimensional heteronuclear NMR.

    PubMed

    Gooley, P R; Johnson, B A; Marcy, A I; Cuca, G C; Salowe, S P; Hagmann, W K; Esser, C K; Springer, J P

    1993-12-07

    Stromelysin-1, a member of the matrix metalloendoprotease family, is a zinc protease involved in the degradation of connective tissue in the extracellular matrix. As a step toward determining the structure of this protein, multidimensional heteronuclear NMR experiments have been applied to an inhibited truncated form of human stromelysin-1. Extensive 1H, 13C, and 15N sequential assignments have been obtained with a combination of three- and four-dimensional experiments. On the basis of sequential and short-range NOEs and 13C alpha chemical shifts, two helices have been delineated, spanning residues Asp-111 to Val-127 and Leu-195 to Ser-206. A third helix spanning residues Asp-238 to Gly-247 is characterized by sequential NOEs and 13C alpha chemical shifts, but not short-range NOEs. The lack of the latter NOEs suggests that this helix is either distorted or mobile. Similarly, sequential and interstrand NOEs and 13C alpha chemical shifts characterize a four-stranded beta-sheet with three parallel strands (Arg-100 to Ile-101, Ile-142 to Ala-147, Asp-177 to Asp-181) and one antiparallel strand (Ala-165 to Tyr-168). Two zinc sites have been identified in stromelysin [Salowe et al. (1992) Biochemistry 31, 4535-4540]. The NMR spectral properties, including chemical shift, pH dependence, and proton coupling of the imidazole nitrogens of six histidine residues (151, 166, 179, 201, 205, and 211), invariant in the matrix metalloendoprotease family, suggest that these residues are zinc ligands. NOE data indicate that these histidines form two clusters: one ligates the catalytic zinc (His-201, -205, and -211), and the other ligates a structural zinc (His-151, -166, and -179). Heteronuclear multiple quantum correlated spectra and specific labeling experiments indicate His-151, -179, -201, -205, and -211 are in the N delta 1H tautomer and His-166 is in the N epsilon 2H tautomer.

  10. Synthesis and Characterization of Gold Clusters Ligated with 1,3-Bis(dicyclohexylphosphino)propane

    SciTech Connect

    Johnson, Grant E.; Priest, Thomas A.; Laskin, Julia

    2013-09-01

    In this multidisciplinary study we combine chemical reduction synthesis of novel gold clusters in solution with high-resolution analytical mass spectrometry (MS) to gain insight into the composition of the gold clusters and how their size, ionic charge state and ligand substitution influences their gas-phase fragmentation pathways. Ultra small cationic gold clusters ligated with 1,3-bis(dicyclohexylphosphino)propane (DCPP) were synthesized for the first time and introduced into the gas phase using electrospray ionization (ESI). Mass-selected cluster ions were fragmented employing collision induced dissociation (CID) and the product ions were analysed using MS. The solutions were found to contain the multiply charged cationic gold clusters Au9L43+, Au13L53+, Au6L32+, Au8L32+ and Au10L42+ (L = DCPP). The gas-phase fragmentation pathways of these cluster ions were examined systematically employing CID combined with MS. In addition, CID experiments were performed on related gold clusters of the same size and ionic charge state but capped with 1,3-bis(diphenylphosphino)propane (DPPP) ligands containing phenyl functional groups at the two phosphine centers instead of cyclohexane rings. It is shown that this relatively small change in the molecular substitution of the two phosphine centers in diphosphine ligands (C6H11 versus C6H5) exerts a pronounced influence on the size of the species that are preferentially formed in solution during reduction synthesis as well as the gas-phase fragmentation channels of otherwise identical gold cluster ions. The mass spectrometry results indicate that in addition to the length of the alkyl chain between the two phosphine centers, the substituents at the phosphine centers also play a crucial role in determining the composition, size and stability of diphosphine ligated gold clusters synthesized in solution.

  11. Efficient in situ detection of mRNAs using the Chlorella virus DNA ligase for padlock probe ligation.

    PubMed

    Schneider, Nils; Meier, Matthias

    2017-02-01

    Padlock probes are single-stranded DNA molecules that are circularized upon hybridization to their target sequence by a DNA ligase. In the following, the circulated padlock probes are amplified and detected with fluorescently labeled probes complementary to the amplification product. The hallmark of padlock probe assays is a high detection specificity gained by the ligation reaction. Concomitantly, the ligation reaction is the largest drawback for a quantitative in situ detection of mRNAs due to the low affinities of common DNA or RNA ligases to RNA-DNA duplex strands. Therefore, current protocols require that mRNAs be reverse transcribed to DNA before detection with padlock probes. Recently, it was found that the DNA ligase from Paramecium bursaria Chlorella virus 1 (PBCV-1) is able to efficiently ligate RNA-splinted DNA. Hence, we designed a padlock probe assay for direct in situ detection of mRNAs using the PBCV-1 DNA ligase. Experimental single-cell data were used to optimize and characterize the efficiency of mRNA detection with padlock probes. Our results demonstrate that the PBCV-1 DNA ligase overcomes the efficiency limitation of current protocols for direct in situ mRNA detection, making the PBCV-1 DNA ligase an attractive tool to simplify in situ ligation sequencing applications.

  12. Electrochemical biosensors for detection of point mutation based on surface ligation reaction and oligonucleotides modified gold nanoparticles.

    PubMed

    Wang, Qing; Yang, Lijuan; Yang, Xiaohai; Wang, Kemin; He, Leiliang; Zhu, Jinqing

    2011-03-04

    An electrochemical method for point mutation detection based on surface ligation reaction and oligonucleotides (ODNs) modified gold nanoparticles (AuNPs) was demonstrated. Point mutation identification was achieved using Escherichia coli DNA ligase. This system for point mutation detection relied on a sandwich assay comprising capture ODN immobilized on Au electrodes, target ODN and ligation ODN. Because of the sequence-specific surface reactions of E. coli DNA ligase, the ligation ODN covalently linked to the capture ODN only in the presence of a perfectly complementary target ODN. The presence of ligation products on Au electrode was detected using chronocoulometry through hybridization with reporter ODN modified AuNPs. The use of AuNPs improved the sensitivity of chronocoulometry in this approach, a detection limit of 0.9 pM complementary ODN was obtained. For single base mismatched ODN (smODN), a negligible signal was observed. Even if the concentration ratio of complementary ODN to smODN was decreased to 1:1000, a detectable signal was observed. This work may provide a specific, sensitive and cost-efficient approach for point mutant detection.

  13. Highly efficient coupling of beta-substituted aminoethane sulfonyl azides with thio acids, toward a new chemical ligation reaction.

    PubMed

    Merkx, Remco; Brouwer, Arwin J; Rijkers, Dirk T S; Liskamp, Rob M J

    2005-03-17

    [reaction: see text] A highly efficient coupling of protected beta-substituted aminoethane sulfonyl azides with thio acids is reported. In the case of peptide thio acids, this method encompasses a new chemoselective ligation method. Furthermore, the resulting alpha-amino acyl sulfonamides can be alkylated with suitable electrophiles to obtain densely functionalized sulfonamide scaffolds.

  14. Disclosure of a structural milieu for the proximity ligation reveals the elusive nature of an active chromatin hub.

    PubMed

    Gavrilov, Alexey A; Gushchanskaya, Ekaterina S; Strelkova, Olga; Zhironkina, Oksana; Kireev, Igor I; Iarovaia, Olga V; Razin, Sergey V

    2013-04-01

    The current progress in the study of the spatial organization of interphase chromosomes became possible owing to the development of the chromosome conformation capture (3C) protocol. The crucial step of this protocol is the proximity ligation-preferential ligation of DNA fragments assumed to be joined within nuclei by protein bridges and solubilized as a common complex after formaldehyde cross-linking and DNA cleavage. Here, we show that a substantial, and in some cases the major, part of DNA is not solubilized from cross-linked nuclei treated with restriction endonuclease(s) and sodium dodecyl sulphate and that this treatment neither causes lysis of the nucleus nor drastically affects its internal organization. Analysis of the ligation frequencies of the mouse β-globin gene domain DNA fragments demonstrated that the previously reported 3C signals were generated predominantly, if not exclusively, in the insoluble portion of the 3C material. The proximity ligation thus occurs within the cross-linked chromatin cage in non-lysed nuclei. The finding does not compromise the 3C protocol but allows the consideration of an active chromatin hub as a folded chromatin domain or a nuclear compartment rather than a rigid complex of regulatory elements.

  15. Ligation and quaternary structure induced changes in the heme pocket of hemoglobin: a transient resonance Raman study.

    PubMed

    Friedman, J M; Stepnoski, R A; Stavola, M; Ondrias, M R; Cone, R L

    1982-04-27

    The extent to which ligation and quaternary structure modify the heme-heme pocket configuration is determined by generating and analyzing transient resonance Raman spectra from various photolyzed and partially photolyzed hemoglobins (Hb). From small frequently shifts in Raman band I (approximately 1355 cm-1) it is determined that ligation induces a configurational change about the heme. The extent to which ligation modifies the heme pocket is influenced by the quaternary structure. With respect to the structural parameter responsible for variations in the pi orbital electron density of the porphyrin, the degree of alteration of the heme pocket configuration relative to deoxy-Hb(T) follows the sequence: liganded Hb(R) greater than liganded Hb(R) + IHP greater than liganded Hb(T) [alpha chain greater than beta chain] greater than deoxy-Hb(R). This progression of configurations also forms a sequence with respect to the "retentiveness" of the heme pocket as reflected in the ligand dynamics associated with geminate recombination. The results indicate that the heme-heme pocket of the R-state Hb's, relative to those of the T-state species, favors ligand retention in a dynamic, as well as thermodynamic, sense. The analysis of these and other related data implicates a ligation and quaternary structure modulated electronic and/or electrostatic interaction between the pi system of the porphyrin and the surrounding heme pocket as the basis for this variation in ligand dynamics as well as for the energetics of cooperativity.

  16. New bipolar tissue ligator combines constant tissue compression and temperature guidance: histologic study and implications for treatment of hemorrhoids

    PubMed Central

    Piskun, Gregory; Tucker, Robert

    2012-01-01

    Background Several minimally invasive technologies are available to treat common soft tissue lesions including symptomatic hemorrhoids. The use of energy to deliver heat and coagulate target lesions is commonly practiced. This study compares the histologic effects produced on intestinal tissues by two energy-based systems which employ different approaches of heat delivery. Methods Two heat delivery systems were evaluated in vivo in a single porcine subject: infrared coagulator and bipolar tissue ligator utilizing constant tissue compression and temperature guidance. Eighteen treatment sites divided into three groups of six were assessed. Treatment site temperature was measured and the effects of thermal treatment in the mucosa, submucosa, submucosal vessels, and muscularis layer were scored. Lateral thermal spread beyond the energy application site was also assessed. Results Treatment site temperatures were much lower in the bipolar ligator group than in the infrared coagulator group. The mucosal and submucosal tissue changes observed in tissues treated with infrared energy and bipolar energy at 55°C were similar. Both the mucosal and submucosal tissue changes with bipolar energy at 50°C were significantly less. Conclusion Both devices achieved similar histologic results. However, the unique design of the bipolar ligator, which allows consistent capture, constant compression, and temperature monitoring of target tissue, accomplished the desired histologic changes with less muscular damage at much lower temperatures than the infrared coagulator. The use of bipolar ligation could offer clinical advantages such as reduced patient pain and a minimized chance of heat-related collateral tissue damage. PMID:23152714

  17. Evaluation of the force generated by gradual deflection of orthodontic wires in conventional metallic, esthetic, and self-ligating brackets

    PubMed Central

    Francisconi, Manoela Fávaro; Janson, Guilherme; Henriques, José Fernando Castanha; de Freitas, Karina Maria Salvatore

    2016-01-01

    ABSTRACT Objective: The purpose of this study was to evaluate the deflection forces of Nitinol orthodontic wires placed in different types of brackets: metallic, reinforced polycarbonate with metallic slots, sapphire, passive and active self-ligating, by assessing strength values variation according to gradual increase in wire diameter and deflection and comparing different combinations in the different deflections. Material and Methods: Specimens were set in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342), using the ISO 15841 protocol. Data were subjected to One-way ANOVA, followed by Tukey tests (p<0.05). Results: Self-ligating brackets presented the most similar behavior to each other. For conventional brackets there was no consistent behavior for any of the deflections studied. Conclusions: Self-ligating brackets presented the most consistent and predictable results while conventional brackets, as esthetic brackets, showed very different patterns of forces. Self-ligating brackets showed higher strength in all deflections when compared with the others, in 0.020-inch wires. PMID:27812620

  18. Detection of single-nucleotide polymorphisms with novel leaky surface acoustic wave biosensors, DNA ligation and enzymatic signal amplification.

    PubMed

    Xu, Qinghua; Chang, Kai; Lu, Weiping; Chen, Wei; Ding, Yi; Jia, Shuangrong; Zhang, Kejun; Li, Fake; Shi, Jianfeng; Cao, Liang; Deng, Shaoli; Chen, Ming

    2012-03-15

    This manuscript describes a new technique for detecting single-nucleotide polymorphisms (SNPs) by integrating a leaky surface acoustic wave (LSAW) biosensor, enzymatic DNA ligation and enzymatic signal amplification. In this technique, the DNA target is hybridized with a capture probe immobilized on the surface of a LSAW biosensor. Then, the hybridized sequence is ligated to biotinylated allele-specific detection probe using Taq DNA ligase. The ligation does not take place if there is a single-nucleotide mismatch between the target and the capture probe. The ligated detection probe is transformed into a streptavidin-horseradish peroxidase (SA-HRP) terminal group via a biotin-streptavidin complex. Then, the SA-HRP group catalyzes the polymerization of 3,3-diaminobenzidine (DAB) to form a surface precipitate, thus effectively increasing the sensitivity of detecting surface mass changes and allowing detection of SNPs. Optimal detection conditions were found to be: 0.3 mol/L sodium ion concentration in PBS, pH 7.6, capture probe concentration 0.5 μmol/L and target sequence concentration 1.0 μmol/L. The detection limit was found to be 1 × 10(-12)mol/L. Using this technique, we were able to detect a single-point mutation at nucleotide A2293G in Japanese encephalitis virus.

  19. Synthesis of histone proteins by CPE ligation using a recombinant peptide as the C-terminal building block.

    PubMed

    Kawakami, Toru; Yoshikawa, Ryo; Fujiyoshi, Yuki; Mishima, Yuichi; Hojo, Hironobu; Tajima, Shoji; Suetake, Isao

    2015-11-01

    The post-translational modification of histones plays an important role in gene expression. We report herein on a method for synthesizing such modified histones by ligating chemically prepared N-terminal peptides and C-terminal recombinant peptide building blocks. Based on their chemical synthesis, core histones can be categorized as two types; histones H2A, H2B and H4 which contain no Cys residues, and histone H3 which contains a Cys residue(s) in the C-terminal region. A combination of native chemical ligation and desulphurization can be simply used to prepare histones without Cys residues. For the synthesis of histone H3, the endogenous Cys residue(s) must be selectively protected, while keeping the N-terminal Cys residue of the C-terminal building block that is introduced for purposes of chemical ligation unprotected. To this end, a phenacyl group was successfully utilized to protect endogenous Cys residue(s), and the recombinant peptide was ligated with a peptide containing a Cys-Pro ester (CPE) sequence as a thioester precursor. Using this approach it was possible to prepare all of the core histones H2A, H2B, H3 and H4 with any modifications. The resulting proteins could then be used to prepare a core histone library of proteins that have been post-translationally modified.

  20. Enamel demineralization with two forms of archwire ligation investigated using an in situ caries model--a pilot study.

    PubMed

    Gameiro, Gustavo Hauber; Nouer, Darcy Flávio; Cenci, Maximiliano Sérgio; Cury, Jaime Aparecido

    2009-10-01

    A modified in situ model to assess enamel demineralization around orthodontic devices was developed and a pilot study was conducted to evaluate two types of archwire ligation. Enamel blocks were placed in palatal removable appliances where orthodontic brackets were bonded. The brackets on one side of the appliance were ligated with elastomeric rings and those on the other side with stainless steel wires. Four volunteers (two males, two females), mean age 27 years, wore the appliances for 14 days during which time a 20 per cent sucrose solution was dripped eight times a day onto the enamel blocks. The biofilm formed around the brackets was collected for microbiological analyses and the mineral loss around the brackets was determined by cross-sectional microhardness measurement. The ligatures evaluated did not differ significantly from each other regarding biofilm weight, total bacteria, total streptococci, mutans streptococci, or lactobacilli counts (P > 0.05, Wilcoxon paired test). Enamel demineralization was also not different around the brackets for the different ligation methods (P > 0.05, split-split-plot analysis of variance). However, a statistical power analysis based on the data showed a trend to higher demineralization around brackets ligated with elastomeric rings. The developed modified in situ model may be suitable to assess the caries potential of clinical procedures used in orthodontic treatment.