Competitive ability of cultivated rice against weedy rice biotypes – A review

Weedy rice has been identified as a threat to rice production worldwide. Its phenotypic and genotypic diversity and its potential to compete against rice in all development stages from germination to maturity have resulted in a loss of rice yield and grain quality, which is remarkably high in directseeded rice cultivation. Weedy rice dormancy varies, it has a higher germination rate, and tolerates deeper germination depth compared to rice cultivars. Interactions of weedy rice with cultivars often reflect early vigor, more tillering, nutrient utilization ability for shoot development with respect to rice cultivars even though the latter also show an improvement in shoot development under competition. An exponential relationship has been reported between cultivated rice loss and weedy rice density: this is true for all rice cultivars. The degree of loss is dependent on the competitive ability of the rice cultivar being studied, and each weedy rice biotype also interacts differently. Hence, the need for a comprehensive study of the biology of various weedy rice variants. Difficulties arise in the management of weedy rice due to its physiological, anatomical, and morphological similarities to cultivated rice. The manipulation of the environment to improve cultivated rice production and suppress the emergence of weedy rice variants is important in the management of weedy rice, as well as other cultural practices and use of pesticides. The development of herbicide-resistant rice cultivars is necessary to totally eliminate the weedy rice variants. This review provides information on the competitive ability of weedy rice against rice cultivars; this information is essential to create management options to control weedy rice.

Endoscopic capacity in West Africa.

Background: Levels of endoscopic demand and capacity in West Africa are unclear. Objectives: This paper aims to: 1. describe the current labor and endoscopic capacity, 2. quantify the impact of a mixed-methods endoscopy course on healthcare professionals in West Africa, and 3. quantify the types of diagnoses encountered. Methods: In a three-day course, healthcare professionals were surveyed on endoscopic resources and capacity and were taught through active observation of live cases, case discussion, simulator experience and didactics. Before and after didactics, multiplechoice exams as well as questionnaires were administered to assess for course efficacy. Also, a case series of 23 patients needing upper GI endoscopy was done. Results: In surveying physicians, less than half had resources to perform an EGD and none could perform an ERCP, while waiting time for emergency endoscopy in urban populations was at least one day. In assessing improvement in medical knowledge among participants after didactics, objective data paired with subjective responses was more useful than either alone. Of 23 patients who received endoscopy, 7 required endoscopic intervention with 6 having gastric or esophageal varices. Currently the endoscopic capacity in West Africa is not sufficient. A formal GI course with simulation and didactics improves gastrointestinal knowledge amongst participants.

Mean Platelet Volume (MPV), Platelet Distribution Width (PDW), Platelet Count and Plateletcrit (PCT) as predictors of in-hospital paediatric mortality: a case-control Study.

Background: Thrombocytopenia has been shown to predict mortality. We hypothesize that platelet indices may be more useful prognostic indicators. Our study subjects were children one month to 14 years old admitted to our hospital. Aim: To determine whether platelet count, plateletcrit (PCT), mean platelet volume (MPV) and platelet distribution width (PDW) and their ratios can predict mortality in hospitalised children. Methods: Children who died during hospital stay were the cases. Controls were age matched children admitted contemporaneously. The first blood sample after admission was used for analysis. Receiver operating characteristic (ROC) curve was used to identify the best threshold for measured variables and the ratios studied. Multiple regression analysis was done to identify independent predictors of mortality. Results: Forty cases and forty controls were studied. Platelet count, PCT and the ratios of MPV/Platelet count, MPV/PCT, PDW/Platelet count, PDW/PCT and MPV x PDW/Platelet count x PCT were significantly different among children who survived compared to those who died. On multiple regression analysis the ratio of MPV/PCT, PDW/Platelet count and MPV/ Platelet count were risk factors for mortality with an odds ratio of 4.31(95% CI, 1.69-10.99), 3.86 (95% CI, 1.53-9.75), 3.45 (95% CI, 1.38-8.64) respectively. In 67% of the patients who died MPV/PCT ratio was above 41.8 and PDW/Platelet count was above 3.86. In 65% of patients who died MPV/Platelet count was above 3.45. Conclusion: The MPV/PCT, PDW/Platelet count and MPV/Platelet count, in the first sample after admission in this case control study were predictors of mortality and could predict 65% to 67% of deaths accurately.

Efficacy and Safety of Using Amplatzer Ductal Occluder for Transcatheter Closure of Perimembranous Ventricular Septal Defect in Pediatrics

Background: Perimembranous Ventricular Septal Defect (PMVSD) is the most common subtype of ventricular septal defects. Transcatheter closure of PMVSD is a challenging procedure in management of moderate or large defects. Objectives: The purpose of this study was to show that transcatheter closure of perimembranous ventricular septal defect with Amplatzer Ductal Occluder (ADO) is an effective and safe method. Patients and Methods: Between April 2012 and April 2013, 28 patients underwent percutaneous closure of PMVSD using ADO. After obtaining the size of VSD from the ventriculogram a device at least 2 mm larger than the narrowest diameter of VSD at right ventricular side was chosen. The device deployed after confirmation of its good position by echocardiography and left ventriculography. Follow up evaluations were done 1 month, 6 months, 12 months and yearly after discharge with transthoracic echocardiography and 12 lead electrocardiography. Results: The mean age of patients at procedure was 4.7 ± 6.3 (range 2 to 14) years, mean weight 14.7 ± 10.5 (range 10 to 40) kg. The mean defect size of the right ventricular side was 4.5 ± 1.6 mm. The average device size used was 7.3 ± 3.2mm (range 4 to 12 mm). The ADOs were successfully implanted in all patients. The VSD occlusion rate was 65.7% at completion of the procedure, rising up to 79.5% at discharge and 96.4% during follow-up. Small residual shunts were seen at completion of the procedure, but they disappeared during follow-up in all but one patient. The mean follow-up period was 8.3 ± 3.6 months (range 1 to 18 months). Complete atrioventricular block (CAVB), major complication or death was not observed in our study. Conclusions: Transcatheter closure of PMVSD with ADO in children is a safe and effective treatment associated with excellent success and closure rates, but long-term follow-up in a large number of patients would be warranted.

Synthesis and antibacterial profile of novel azomethine derivatives of β-phenylacrolein moiety

Purpose: To develop some novel molecules effective against antibiotic-resistant bacterial infections. Methods: A series of azomethines (SB-1 to SB-6) were synthesized from β-phenyl acrolein moiety. The structures of the synthesized compounds were confirmed on the basis of their UV ultra-violet (UV) spectroscopy (λmax: 200 - 400 nm), Fourier transform infra-red (FTIR, vibrational frequency: 500-4000 cm-1), 1H nuclear magnetic resonance (NMR, chemical shift: 0 - 10 ppm), 13C NMR (chemical shift: 0 - 200 ppm), mass spectrometry (m/z values: 0 - 500) and carbon hydrogen nitrogen (CHN) elemental analysis. The new compounds were screened for antibacterial activity by test-tube dilution and disc diffusion methods using gentamicin as reference standard. Results: The structures of azomethine were in full agreement with their spectral data. Among all the synthesized compounds, compounds SB-5 and SB-6 exhibited the highest minimum inhibitory concentration (MIC) of 62.5 μg/mL. At MIC of 250 μg/mL, all compounds SB-1 to SB-6 displayed significant antibacterial activity, compared to gentamycin (p < 0.05). SB-5 and SB-6 were active against S. aureus, P. aeruginosa and K. pneumoniae; SB-3 was active against B. subtilis and S. aureus. SB-4 was active against P. aeruginosa and S. aureus while SB-1 and SB-2 were active against S. aureus. Conclusion: The synthesized compounds possess antibacterial activities compared to those of gentamycin.

Bioequivalence evaluation of new microparticulate capsule and marketed tablet dosage forms of lornoxicam in healthy volunteers

Purpose: To compare oral bioavailability and pharmacokinetic parameters of different lornoxicam formulations and to assess similarity in plasma level profiles by statistical techniques. Methods: An open-label, two-period crossover trial was followed in 24 healthy Pakistani volunteers (22 males, 2 females). Each participant received a single dose of lornoxicam controlled release (CR) microparticles and two doses (morning and evening) of conventional lornoxicam immediate release (IR) tablet formulation. The microparticles were prepared by spray drying method. The formulations were administered again in an alternate manner after a washout period of one week. Pharmacokinetic parameters were determined by Kinetica 4.0 software using plasma concentration-time data. Moreover, data were statistically analyzed at 90 % confidence interval (CI) and Schuirmann’s two one-sided t-test procedure. Results: Peak plasma concentration (Cmax) was 20.2 % lower for CR formulation compared to IR formulation (270.90 ng/ml vs 339.44 ng/ml, respectively) while time taken to attain Cmax (tmax) was 5.25 and 2.08 h, respectively. Area under the plasma drug level versus time (AUC) curve was comparable for both CR and IR formulations. The 90 % confidence interval (CI) values computed for Cmax, AUC0-24, and AUC0-∞ , after log transformation, were 87.21, 108.51 and 102.74 %, respectively, and were within predefined bioequivalence range (80 - 125 %). Conclusion: The findings suggest that CR formulation of lornoxicam did not change the overall pharmacokinetic properties of lornoxicam in terms of extent and rate of lornoxicam absorption.

Synthesis and antimicrobial activity of some 2- Piperidinomethylamino-4-(7-H/substituted coumarin-3-yl)- 6-chlorosubstitutedphenyl pyrimidines

Purpose: To prepare and evaluate some 2-piperidinomethylamino-4-(7-H/substitutedcoumarin-3-yl)-6- chlorosubstitutedphenyl pyrimidines as antimicrobial agents. Methods: Some 2-piperidinomethylamino-4-(7-H/substitutedcoumarin-3-yl)-6-chlorosubstitutedphenyl pyrimidines were prepared by reacting 2-amino-4-(7-H/substitutedcoumarin-3-yl)-6- (chlorosubstitutedphenyl) pyrimidines with piperidine and formaldehyde. The chemical structures of the synthesized compounds were elucidated by Fourier transform infrared (FTIR), 1H-nuclear magnetic resonance (1H-NMR), mass spectrometry and elemental analysis. These compounds were investigated for their antimicrobial activity against ten bacteria and five fungi by serial plate dilution method using standard drugs, namely, ofloxacin and ketoconazole, respectively, and their minimum inhibitory concentrations (MICs) were also determined. Results: A total of eighteen new compounds (1a-18a) were synthesized. Compound 6a (MIC = 50 μg/mL; p < 0.05 or less) displayed the highest activity against S. aureus , E. faecalis , Staphylococcus epidermidis , B. subtilis , and B. cereus . Compound 6a further showed good activity (MIC = 25 μg/mL; p < 0.05 or less) against E. coli ; P. aeruginosa K. pneumonia , B. bronchiseptica , and P. vulgaris . Compounds 6a (MIC = 25 μg/mL; p < 0.0001) and 17a (MIC = 25 μg/mL; p < 0.0001) displayed very good activity against C. albicans , A. niger , A. flavus , M. purpureous , and P. citrinum , respectively. Analysis of structure-activity relationship revealed that the presence of bromo group at 7-postion of the coumarin moiety along with the 4-chlorophenyl group at position-6 of the pyrimidine ring is critical for antimicrobial activity against Gram-positive bacteria, Gram negative bacteria and fungi. Conclusion: The synthesized 2-piperidino derivatives are better antifungal and antibacterial agents than the earlier reported 2-morpholino derivatives, but require further investigations against other microbial strains to ascertain their broad spectrum antimicrobial activity.