Assessment of Oral Anticoagulation with Vitamin K Antagonists in Patients Living in a Low-Income Country of West Africa

Introduction: Despite the rise of direct oral anticoagulants (DOACs), vitamin K antagonists (VKA) remain the most widely used oral anticoagulants in developing countries. The aim of this study was to estimate the prevalence of good anticoagulation in patients treated with VKA in Lomé and describe associated factors. Methods: This was a cross-sectional study conducted from November 2019 to October 2020 in the cardiology departments of two University teaching hospitals in Lomé (CHU Sylvanus Olympio and CHU Campus), involving patients on VKA for ≥3 months, with a target international normalized ratio (INR) of 2.5 and a therapeutic margin between 2 and 3. The quality of anticoagulation was assessed by the time in therapeutic range (TTR) which was assessed by the Rosendaal method. Good anticoagulation was defined by a TTR > 70%. Results: A total of 344 patients were included (mean age = 58 ± 13.8 years, women = 56.1%). Indications for VKA treatment were represented by venous thromboembolic disease (43.3%), supraventricular arrhythmia (28.2%), severe left ventricular systolic dysfunction (19.8%) and pulmonary hypertension (8.7%). The average TTR was 47.6 ± 20.8%. The rate of good anticoagulation was 17.7%. Factors associated with good anticoagulation were the use of fluindione vs acenocoumarol (OR = 11.17;95% CI: 3.2 - 39.6;p = 0.0002), concomitant low-dose aspirin (OR 4.44;95% CI: 1.4 - 13.9;p = 0.01) and INR monitoring exclusively by the patient himself (OR = 4.92;95% CI: 1.5 - 16.3;p = 0.008). The rate of thromboembolic and hemorrhagic complications was each 2.6% and was not correlated with the quality of anticoagulation. Quality of anticoagulation by VKAs was poor in our practice. Factors associated with good anticoagulation were the use of fluindione vs acenocoumarol, concomitant low-dose aspirin and monitoring of INR exclusively by the patient himself. Conclusion: The quality of oral anticoagulation by VKAs could be improved in our practice by the creation of anticoagulation clinics for better therapeutic education of patients and efficient management of VKA dose, and the use of prescription assistance software.

Exploration of standard dosage for GnRH antagonist protocol and dosage adjustments after premature luteinizing hormone surge

The gonadotropin-releasing hormone (GnRH) antagonist protocol has emerged as an efficacious alternative to the GnRH agonist protocol for controlled ovarian hyperstimulation (COH) during in vitro fertilization (IVF) cycles, and has been demonstrated applicability in infertile female patients with diverse ovarian responses. While the clinical implementation of the antagonist COH protocol has achieved widespread consensus, opportunities for refinement persist. Therefore, this review article focuses on the advantages and disadvantages of GnRH antagonist protocol, the selection of optimal standard doses, and the strategies for adjusting antagonist doses after the premature luteinizing hormone (LH) surge, aiming to provide more reasonable and scientific recommendations for the application of this scheme.

Effects of 5-HT2B, 5-HT3 and 5-HT4 receptor antagonists on gastrointestinal motor activity in dogs

AIM:To study the effects of 5-hydroxytryptamine(5-HT)receptor antagonists on normal colonic motor activity in conscious dogs.METHODS:Colonic motor activity was recorded using a strain gauge force transducer in 5 dogs before and after 5-HT2B,5-HT3 and 5-HT4 receptor antagonist administration.The force transducers were implanted on the serosal surfaces of the gastric antrum,terminal ileum,ileocecal sphincter and colon.Test materials or vehicle alone was administered as an intravenous bolus injection during a quiescent period of the whole colon in the interdigestive state.The effects of these receptor antagonists on normal gastrointestinal motor activity were analyzed.RESULTS:5-HT2B,5-HT3 and 5-HT4 receptor antagonists had no contractile effect on the fasting canine terminal ileum.The 5-HT3 and 5-HT4 receptor antagonists inhibited phaseⅢof the interdigestive motor complex of the antrum and significantly inhibited colonic motor activity.In the proximal colon,the inhibitory effect was dose dependent.Dose dependency,however,was not observed in the distal colon.The 5-HT2B receptor antagonist had no contractile effect on normal colonic motor activity.CONCLUSION:The 5-HT3 and 5-HT4 receptor antagonists inhibited normal colonic motor activity.The5-HT2B receptor antagonist had no contractile effect on normal colonic motor activity.

Proton pump inhibitors therapy vs H_2 receptor antagonists therapy for upper gastrointestinal bleeding after endoscopy: A meta-analysis

AIM: To compare the therapeutic effects of proton pump inhibitors vs H2 receptor antagonists for upper gastrointestinal bleeding in patients after successful endoscopy.METHODS: We searched the Cochrane library, MEDLINE, EMBASE and Pub Med for randomized controlled trials until July 2014 for this study. The risk of bias was evaluated by the Cochrane Collaboration's tool and all of the studies had acceptable quality. The main outcomes included mortality, re-bleeding, received surgery rate, blood transfusion units and hospital stay time. These outcomes were estimated using odds ratios(OR) and mean difference with 95% confidence interval(CI). Rev Man 5.3.3 software and Stata 12.0 software were used for data analyses. RESULTS: Ten randomized controlled trials involving 1283 patients were included in this review; 678 subjects were in the proton pump inhibitors(PPI) group and the remaining 605 subjects were in the H2 receptor antagonists(H2RA) group. The meta-analysis results revealed that after successful endoscopic therapy, compared with H2 RA, PPI therapy had statistically significantly decreased the recurrent bleeding rate(OR = 0.36; 95%CI: 0.25-0.51) and receiving surgery rate(OR = 0.29; 95%CI: 0.09-0.96). There were no statistically significant differences in mortality(OR = 0.46; 95%CI: 0.17-1.23). However, significant heterogeneity was present in both the numbers of patients requiring blood transfusion after treatment [weighted mean difference(WMD),-0.70 unit; 95%CI:-1.64- 0.25] and the time that patients remained hospitalized [WMD,-0.77 d; 95%CI:-1.87- 0.34]. The Begg's test(P = 0.283) and Egger's test(P = 0.339) demonstrated that there was no publication bias in our meta-analysis.CONCLUSION: In patients with upper gastrointestinal bleeding after successful endoscopic therapy, compared with H2 RA, PPI may be a more effective therapy.

Synthesis of 4-Amino-5-furyl-2-yl-4H-1, 2, 4-triazole-3-thiol Derivatives as a Novel Class of Endothelin(ET) Receptor Antagonists

A series of novel 3-alkylthio-4-arylideneamino-5-(2-furyl)-1, 2, 4-triazole derivatives were synthesized. Their chemical structures were confirmed with elemental analysis and spectral data. Endothelin(ET) receptor competitive binding assay showed that some compounds exhibited high selective as potent ET-1 receptor antagonist.

Gram-Positive Bacteria Associated with Rice in China and Their Antagonists Against the Pathogens of Sheath Blight and Bakanae Disease in Rice

It is necessary to understand the bacterial populations associated with rice so as to provide more information and natural resources for effective management of major diseases in rice. A survey on screening and identification of gram-positive bacteria was conducted during 1998 2004. Seven hundred and fifty-six rice samples were collected from Zhejiang, Jiangsu, Fujian and Yunnan Provinces, China. Over 1000 bacterial isolates were isolated and tested for colony morphology, pathogenicity, and some characteristics of bacteriology including Gram staining, fluorescent pigment on Kings medium B and microscopic observation for endospore. Together with five standard reference strains, 74 representative gram-positive bacterial isolates were confirmed by Biolog and gas chromatographic analysis of fatty acid methyl esters. Five bacterial species of Bacillus and other three genera were identified and isolates from Bacillus sublitis and Bacillus megaterium, exhibited the most effective inhibition against the pathogens of sheath blight and bakanae disease of rice. A few isolates from Bacillus pumilus and Bacillus megaterium showed weak virulent on rice together with some virulent isolates, risk should be considered when isolates from these species were screened for biocontrol agents.

Spectrofluorimetric method for determination of some angiotensin II receptor antagonists

A simple, rapid, accurate and highly sensitive spectrofluorimetric method has been developed for determination of some angiotensin II receptor antagonists (AIIRA’s), namely Losartan potassium (Los-K), Irbesartan (Irb), Valsartan (Val) and Candesartan cilexetil (Cand) in pure forms as well as in their pharmaceutical dosage forms. All the variables affecting the relative fluorescence intensity (RFI) were studied and optimized. Under the optimum conditions, linear relationships with good correlation coefflcients (0.9982–0.9991) were obtained over the concentration range from 0.006 mg/mL to 1.7 mg/mL. Good accuracy and precision were successfully obtained for the analysis of tablets containing each drug alone or combined with hydrochlorothiazide (HCTZ) without interferences from the co-formulated HCTZ or the additives commonly present in tablets.

Design and synthesis of 2-alkylbenzimidazole derivatives as novel non-peptide angiotensin Ⅱ AT1 receptor antagonists

A series of 2-alkylbenzimidazole derivatives 9a-n have been designed and synthesized as a novel class of non-peptide angiotensin H AT1 receptor antagonists. The synthesized compounds were evaluated for their antagonism of angiotensin H, induced contraction in the rabbit thoracic aortic ring and the results showed that compounds 9a, 9g and 9j exhibited potent antagonistic activity of AT1 receptor.

Synthesis of thiourea derivatives as CCR4 antagonists

A series of thiourea derivatives have been synthesized. Their structures were confirmed by MS and 1H NMR. Several compounds showed potent activities as antagonists of CCR4 receptor.

Support vector classification for SAR of 5-HT3 receptor antagonists

In this work, support vector classification （SVC） algorithm was used to build structure-activity relationship （SAR） model of the 5-hydroxytryptamine type 3 （5-HT3 ） receptor antagonists with 26 compounds. In a benchmark test, SVC was compared with several techniques of machine learning currently used in the field. The prediction performance of the model was discussed on the basis of the leave-one-out cross-validation. The results show that the accuracy of prediction of SVC model was higher than those of back propagation artificial neural network （BP ANN）, K-nearest neighbor （KNN） and Fisher methods.

Effects of mineralocorticoid receptor antagonists on responses to hemorrhagic shock in rats

AIM To evaluate the effects of mineralocorticoid receptor(MR) antagonists on mortality and inflammatory responses after hemorrhagic shock(HS) in rats.METHODS One hundred and two male Sprague–Dawley rats were randomly assigned to one of the following three groups: Control, spironolactone (SPL), and eplerenone(EP) groups. HS was induced by the removal of blood. One half of rats were evaluated to determine mortality, hemodynamics, plasma tumor necrosis factor-alpha(TNF-α) concentrations, and arterial blood gas at 8 h afterHS recovery. In the remainder of rats, the expression levels of genes encoding cytokines were evaluated in liver tissue samples at 1 h after HS recovery. RESULTS The survival rates 8 h after HS recovery were 71%, 94%, and 82% in the control, SPL, and EP groups, respectively. There were no significant differences in survival rates among the three groups (P = 0.219). Furthermore, there were no significant differences in gene expression levels in the liver or plasma TNF-α concentrations among the three groups(P = 0.888).CONCLUSION Pretreatment with MR antagonists did not improve mortality or cytokine responses in the liver after HS recovery in rats.

Medical therapy for clinical benign prostatic hyperplasia:α1 Antagonists,5α reductase inhibitors and their combination

Medical therapy for clinical benign prostatic hyperplasia(BPH)has advanced significantly in the last 2 decades.Many new a1 antagonists and 5a reductase inhibitors(5ARi)are now commercially available.The practicing urologist must decide on the most appropriate medication for his patients,taking into consideration various factors like efficacy,dosing regime,adverse effects,cost,patient’s socioeconomic background,expectations,drug availability and his own clinical experience.The use of combination therapy added further to the complexity in clinical judgment when prescribing.We highlight some of the key points in prescribing a1 antagonists,5ARi and their combination,based on our viewpoints and experience as urologists in an Asian clinical setting.

Endothelin receptor antagonists for the treatment of diabetic nephropathy:A meta-analysis and systematic review

BACKGROUND Diabetic nephropathy(DN)is the main cause of chronic kidney disease and endstage renal disease worldwide.Although available clinical trials have shown that endothelin receptor(ER)antagonists may be a novel and beneficial drug for DN,no consistent conclusions regarding their sufficient effectiveness and safety for patients with DN have been presented.AIM To assess the effectiveness and safety of ER antagonists among patients with DN.METHODS The EMBASE,PubMed,MEDLINE,Cochrane,and ClinicalTrials.gov databases were searched without any language restrictions.Relative risks with 95%confidence intervals(CIs)for dichotomous data and mean differences or standardized mean difference with 95%CIs for continuous data were calculated using Review Manager 5.3 software.Publication bias was assessed using Egger’s test with Stata/SE software.RESULTS We enrolled seven studies with six data sets and 5271 participants.The ER antagonists group showed a significantly greater reduction in albuminuria and more patients with 40%reduction in urinary albumin-to-creatinine ratio than the control group(P<0.0001 and P=0.02,respectively).Subgroup analysis for reductions in estimated glomerular filtration rate(eGFR)showed that for the middle-dosage subgroup,the ER antagonists group exhibited lower eGFR reduction than the control group(P<0.00001;mean difference,0.7095%CI:0.66,0.74).Moreover,significant reductions in systolic and diastolic blood pressure were observed in the invention group.CONCLUSION ER blockades combined with angiotensin converting enzyme inhibitor/angiotensin II type 1 receptor blockers may be an effective treatment to lower blood pressure and reduce proteinuria in DN with declined eGFR.However,attention should be given to adverse events,including cardiac failure,anemia,and hypoglycemia,as well as serious adverse events.

Protective Effects of Calcium Antagonists on Cadmium-induced Toxicity in Rats

Protective effects of calcium antagonists, chlorpromazine (CPZ) and nimodepine (NI-MO), on cadmium-induced toxicity were investigated. After giving CdCl2 (0. 44mg Cd/kg,ip), CPZ (5mg/kg, ip) or NIMO (8mg/kg, po) were administered every day to Sprague-Dawley (S. D. ) rats for a week. Then, urinary N- acetyl-β-D- glucosaminidase (NAG ), uri -nary cadmium and bloocl cadmium were measured. The accumulation of cadmium in the kid-ney cortex, content of renal calmodulin, hemoglobin and the ultrastructural damage of proxi-mal convoluted tubules of rats were examined three weeks after the last administration. Re-sults indicated that the calcium antagonists partly protected against toxic effects induced bycadmium in different manners. These data provide further evidence for the new hypothesisthat the cross effect of cadmium and calcium in calmodulin regulated systems may be responsi-ble for the mechanism of cadmium intoxication. 'The results suggested that the calcium antag-onists could be a new and promising approach in the therapy of heavy metaLinduced diseases

Pharmacophore-guided design,synthesis and evaluation of quinazoline-arylpiperazines as newα_1-adrenoceptor antagonists

一系列 arylpiperazinesquinazoline-2,4-diamine 混合物为 uro 选择的α 1 -adrenoceptor 对手并且 3D 化学药品数据库寻找基于 pharmacophore 被设计并且综合。在里面功能的分析显示出的 vitro 那加重 9 和 14 与 prazosin 相比显示出更好、类似的α 1 -AR antagonistic 活动。

Comparison of PPIs and H_2-receptor antagonists plus prokinetics for dysmotility-like dyspepsia

AIM:To compare efficacy of proton pump inhibitors(PPIs)with H2-receptor antagonists(H2RAs)plus prokinetics(Proks)for dysmotility-like symptoms in functional dyspepsia(FD).METHODS:Subjects were randomized to receive openlabel treatment with either rabeprazole 10 mg od(n= 57)or famotidine 10 mg bid plus mosapride 5 mg tid(n=57)for 4 wk.The primary efficacy endpoint was change(%)from baseline in total dysmotility-like dyspepsia symptom score.The secondary efficacy endpoint was patient satisfaction with treatment.RESULTS:The improvement in dysmotility-like dyspep-sia symptom score on day 28 was significantly greater in the rabeprazole group(22.5%±29.2%of baseline) than the famotidine+mosapride group(53.2%± 58.6%of baseline,P<0.0001).The superior benefit of rabeprazole treatment after 28 d was consistent regardless of Helicobacter pylori status.Significantly more subjects in the rabeprazole group were satisfied or very satisfied with treatment on day 28 than in the famotidine+mosapride group(87.7%vs 59.6%,P= 0.0012).Rabeprazole therapy was the only significant predictor of treatment response(P<0.0001),defined as a total symptom score improvement≥50%.CONCLUSION:PPI monotherapy improves dysmotility-like symptoms significantly better than H2RAs plus Proks,and should be the treatment of first choice for Japanese FD.

Therapy for acute pancreatitis with platelet-activating factor receptor antagonists

Acute pancreatitis (AP) causes release of platelet- activating factor (PAF), which induces systemic effects that contribute to circulatory disturbances and multiple organ failure. PAF is a cell surface secretion of bioactive lipid, which could produce physiological and pathological effects by binding to its cell surface receptor called platelet-activating factor receptor (PAF-R). Studies showed that PAF participates in the occurrence and development of AP and administration of platelet-activating factor receptor antagonists (PAF-RAs) could significantly reduce local and systemic events after AP. PAF has also been implicated as a key mediator in the progression of severe AP, which can lead to complications and unacceptably high mortality rates. Several classes of PAF-RA show PAF- RAs significant local and systemic effects on reducing inflammatory changes. As a preventive treatment, PAF-RA could block a series of PAF-mediated inflammatory injury and thus improve the prognosis of AP. This review introduces the important role of PAF-RA in the treatment of AP.

Screening of chemokine receptor CCR4 antagonists by capillary zone electrophoresis

Abstract CC chemokine receptor 4 （CCR4） is a kind of G-protein-coupled receptor, which plays a pivotal role in allergic inflammation. The interaction between 2-（2-（4-chloro-phenyl）-5-{[（naphthalen-1- ylmethyl）-carbamlyl]-methyl-4-oxo-thiazolidin-3-yl）-N-（3-morpholin-4-yl-propyi）-acetamide （S009） and the N-terminal extracellular tail （ML40） of CCR4 has been validated to be high affinity by capillary zone electrophoresis （CZE）.The S009 is a known CCR4 antagonist. Now, a series of new thiourea derivatives have been synthesized. Compared with positive control S009, they were screened using ML40 as target by CZE to find some new drugs for allergic inflammation diseases. The synthesized compounds XJH-5, XJH-4, XJH-17 and XJH-1 displayed the interaction with ML40, but XJH-9, XJH-10, XJH-I 1, XJH-12, XJH-13, XJH-14, XJH-3, XJH-8, XJH-6, XJH-7, XJH-15, XJH-16 and XJH-2 did not bind to ML40. Both qualification and quantification characterizations of the binding were determined. The affinity of the four compounds was valued by the binding constant, which was similar with the results of chemotactic experiments. The established CEZ method is capable of sensitive and fast screening for a series of lactam analogs in the drug discovery for allergic inflammation diseases.

Effect of endothelin-1 receptor antagonists on histological and ultrastructural changes in the pancreas and trypsinogen activation in the early course of caerulein-induced acute pancreatitis in rats

AIM: To assess the effect of non-selective ETA/B (LU 302872)and selective ETA (LU 302146) antagonist on pancreatic histology and ultrastructure of acinar cells in connection with trypsinogen activation in early caerulein-induced AP.METHODS: Male Wistar rats with caerulein-induced AP,lasting 4 h, were treated i.p. with 10 and 20 mg/kg b.w.of each antagonist. Edema, inflammatory infiltration,necrosis and vacuolization of acinar cells in the pancreas were scored at 0-3 scale. Free active trypsin (FAT), total potential trypsin (TPT) after activation with enterokinase,and index of trypsinogen activation (%FAT/TPT) were assayed in pancreatic homogenates.RESULTS: In untreated AP, the edema, inflammatory infiltration, necrosis and vacuolization increased as compared to control healthy rats (P＜0.01). None of the treatment exerted any meaningful effect on the edema and inflammatory infiltration. The selective antagonist increased slightly the necrosis score to 0.82±0.06 at higher dose (P＜0.05) vs 0.58±0.06 in untreated AP. The nonselective antagonist increased slightly the vacuolization score to 2.41±0.07 at higher dose (P＜0.01) vs 1.88±0.08in untreated AP. The decrease in the number of zymogen granules, disorganization of endoplasmic reticulum,autophagosomes and cytoplasmic vacuoles were more prominent in treated AP than in untreated AP groups.%FAT/TPT in untreated AP increased about four times (18.4±3.8 vs4.8±1.3 in control group without AP, P＜0.001).Treatment of AP with both antagonists did not affect significantly augmented trypsinogen activation.CONCLUSION: The treatment with endothelin-1 receptors (non-selective ETA/B and selective ETA) antagonists has essential effect neither on the edema and inflammatory infiltration nor on trypsinogen activation observed in the early course of caerulein-induced AP. Nevertheless a slight increase of the necrosis and vacuolization score and some of the ultrastructural data could suggest the possibility of their undesired effects in caerulein-induced AP at investigated doses.

The seeming paradox of adenosine receptors as targets for the treatment of Alzheimer's disease: agonists or antagonists?

Alzheimer＇s disease （AD） is the most common neurodegenerative disorder, and its incidence is relatively high among elderly people, affecting about 1-2% of the population between 60-65 years old and rising dramatically （about 30%） in people aged 80 years or older （Selkoe, 2002）. Nowadays, considering the increasing mean lifespan of populations in developed countries, the disease is becoming more and more a health concern, and the search for an effective cure has turned into＂a real need＂.