Delay Time Parameter and Its Confidence Interval of Predictive Time Series of COVID-19 Outbreak Between the First and the Second Wave

The outbreak of coronavirus disease 2019 (COVID-19) has become a major problem facing humans all around the world. For governments, in order to deal with the outbreak and protect the population, it is important to predict the number of infectious cases in the future to monitor the COVID-19 situation. This research aimed to compare the effectiveness of the logistic and the delay logistic time series in predicting the total number of infectious cases by using actual data from four countries, i.e. Thailand, South Korea, Egypt, and Nigeria. The total number of COVID-19 cases was collected during the first and the second wave of the COVID-19 outbreak. The validation and accuracy of the predictive growth curve time series were determined based on statistical values, i.e. the coefficient of determination and the root mean squared percentage error. It was found that the logistic time series was more appropriate for predicting the first wave in the four countries. For the second wave, the delay logistic time series was preferable. Moreover, the confidence interval based on Chebyshev’s inequality of delay time between the first and the second wave of the COVID-19 outbreak is also proposed

ANTIBACTERIAL AND ANTIOXIDANT ACTIVITIES OF LANNA MEDICINAL PLANTS USED IN MAHOOG FORMULA

Objectives: Antibacterial and antioxidant activities of Lanna medicinal plants used in Mahoog formula were investigated.Methods: Dried powders of twenty five Lanna medicinal plants were extracted with ethanol using soxhlet's apparatus and with water by decoction method to obtain ethanolic and water extracts, respectively. Each extract was evaluated for antibacterial activity by agar diffusion technique and antioxidant activity by 2,2´-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical scavenging assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and ferric reducing antioxidant power (FRAP) assay.Results: Most ofLanna medicinal plant extracts were active against gram-positive bacteria. The extract of Caesalpinia sappan (heart wood) showed the highest inhibitory effect on Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Interestingly,the extract of Sindora siamensis (stem) exhibited potent activity against S. aureus as same as C. sappan with MIC and MBC values of 0.049 and 0.098 mg/ml, respectively. The antioxidant activities revealed that the extract of C. sappan and S. siamensis possess significant free radical scavenging and reducing power.Conclusion: Most of the medicinal plants consisted in Mahoog formula revealed antioxidant and antibacterial activities. Thedata obtained from the study will be used as a scientific evidence to support the pharmacological properties of medicinal plants used in Mahoog formula.Â

The optimal parameters of spline regression for SNP-set analysis in genome-wide association study

This research aims to develop a method that is capable and reliable for identifying significant regions in Genome-Wide Association Study based on Spline regression. We evaluate the optimal parameters in the Splines by smoothing and tuning p-values obtained from two methods, Sequence Kernel Association Test using normal weight (SKAT normal weight) and Generalized Higher Criticism (GHC) for testing SNP-set. False positive (FP) and True positive (TP) rates were evaluated under different genetic models for disease with significance thresholds adjusted for multiple hypothesis testing based on the permutation method. The simulated data used in this research are constructed from a control data set in a study of Crohn’s disease which is repeated 1,500 replicates for studies of size 3,000 cases and 3,000 controls. The simulation result shows that the optimal parameter in the Splines on the p-value of SKAT normal weight and GHC under the one disease SNP model simulation are at the degree of freedom 1,000. GHC is shown to be preferable in terms of comparing FP and TP rates but it is disadvantageous compared to SKAT in terms of computational burden time. Finally, the optimal parameter of both methods was applied to real data on Crohn’s disease. Both methods found the important regions of genes NOD2 which are strongly associated with the development and the importance of gene NOD2 which causes Crohn’s disease

Antibacterial and Antioxidant Activities of Various Fraction of Leea rubra (Leeaceae)

The present study was designed to evaluate the antibacterial and antioxidant activities of hexane, ethylacetate and ethanol extracts of Leea rubra (Leeaceae) roots and stems, which has been used as a Lanna Traditional Medicines for Màhòog. Each extract was tested for antibacterial activity by agar diffusion method and microbroth dilution method and antioxidant activity by 2,2´-azino-bis(3-ethyl- benzthiazoline-6-sulfonic acid) (ABTS) free radical scavenging assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and ferric reducing antioxidant power (FRAP) assay. The ethylacetate extract of L. rubra root showed the highest antibacterial activity against gram-positive (IZD=15.5.0±0.5 to 17.5±0.5 mm, MIC=0.098-1.562 mg/ml).  While the ethanolic extract of root showed the strongest antioxidant activity in ABTS, DPPH and FRAP method (TEAC=0.888±0.001, 0.849±0.020 and 0.733±0.037, respectively). The data obtained from this study confirms the traditional use of L. rubra for treatment Màhòog. Keywords: Leea rubra, antioxidant activity, antibacterial activit

The efficiency of single SNP and SNP-set analysis in genome-wide association studies

The objective of this research is to compare and identify effective methods for the identification of gene loci associated with a disease outcome in the analysis of genome-wide data. We evaluate three methods which are single SNP analysis, Sequence Kernel Association Test (SKAT) and the recently proposed Generalized Higher Criticism (GHC). The simulated data used in this research were constructed from a control data set in a study of Crohn's disease. True positive (TP) and false positive rate (FP) were evaluated under different genetic models for disease with significant thresholds adjusted for multiple hypothesis testing based on the permutation method. The findings are mixed with all three methods giving similar TP rates under some disease models and different rates for other models. Overall, GHC is shown to be preferable in terms of error rates but it is disadvantageous in terms of computational efficiency

Probiotic Lactobacillus paracasei effect on cariogenic bacterial flora

Lactobacillus paracasei has been demonstrated to inhibit the growth of many pathogenic microbes such as Streptococcus mutans, in vitro. However, its clinical application remains unclear. Here, we examined whether a novel probiotic L. paracasei GMNL-33 may reduce the caries-associated salivary microbial counts in healthy adults. Seventy-eight subjects (aged 20 to 26) had completed this double-blinded, randomized, placebo-controlled study. A probiotic/test (n = 42) and a control group (n = 36) took a L. paracasei GMNL-33 and a placebo oral tablet three times per day for 2 weeks, respectively. Bacterial counts of salivary S. mutans, lactobacilli, and salivary buffer capacity were measured with chair-side kits at the beginning (T1), the completion (T2) of medication, and 2 weeks after medication (T3). The results did not show differences in the counts of S. mutans and lactobacilli between probiotic and control groups at T1, T2, and T3. Nevertheless, within the probiotic group, an interesting probiotic effect was noticed. Between T1 and T2, no inhibitory effect against S. mutans was observed. However, a significant count reduction in the salivary S. mutans was detected between T2 and T3 (p = 0.016). Thus, a 2-week period of medication via oral administration route may be needed for L. paracasei GMNL-33 to be effective in the probiotic action

Assessment of Microbial Diversity in Biofilms Recovered from Endotracheal Tubes Using Culture Dependent and Independent Approaches

Ventilator-associated pneumonia (VAP) is a common nosocomial infection in mechanically ventilated patients. Biofilm formation is one of the mechanisms through which the endotracheal tube (ET) facilitates bacterial contamination of the lower airways. In the present study, we analyzed the composition of the ET biofilm flora by means of culture dependent and culture independent (16 S rRNA gene clone libraries and pyrosequencing) approaches. Overall, the microbial diversity was high and members of different phylogenetic lineages were detected (Actinobacteria, beta-Proteobacteria, Candida spp., Clostridia, epsilon-Proteobacteria, Firmicutes, Fusobacteria and gamma-Proteobacteria). Culture dependent analysis, based on the use of selective growth media and conventional microbiological tests, resulted in the identification of typical aerobic nosocomial pathogens which are known to play a role in the development of VAP, e.g. Staphylococcus aureus and Pseudomonas aeruginosa. Other opportunistic pathogens were also identified, including Staphylococcus epidermidis and Kocuria varians. In general, there was little correlation between the results obtained by sequencing 16 S rRNA gene clone libraries and by cultivation. Pyrosequencing of PCR amplified 16 S rRNA genes of four selected samples resulted in the identification of a much wider variety of bacteria. The results from the pyrosequencing analysis suggest that these four samples were dominated by members of the normal oral flora such as Prevotella spp., Peptostreptococcus spp. and lactic acid bacteria. A combination of methods is recommended to obtain a complete picture of the microbial diversity of the ET biofilm

Prospects for the development of probiotics and prebiotics for oral applications

There has been a paradigm shift towards an ecological and microbial community-based approach to understanding oral diseases. This has significant implications for approaches to therapy and has raised the possibility of developing novel strategies through manipulation of the resident oral microbiota and modulation of host immune responses. The increased popularity of using probiotic bacteria and/or prebiotic supplements to improve gastrointestinal health has prompted interest in the utility of this approach for oral applications. Evidence now suggests that probiotics may function not only by direct inhibition of, or enhanced competition with, pathogenic micro-organisms, but also by more subtle mechanisms including modulation of the mucosal immune system. Similarly, prebiotics could promote the growth of beneficial micro-organisms that comprise part of the resident microbiota. The evidence for the use of pro or prebiotics for the prevention of caries or periodontal diseases is reviewed, and issues that could arise from their use, as well as questions that still need to be answered, are raised. A complete understanding of the broad ecological changes induced in the mouth by probiotics or prebiotics will be essential to assess their long-term consequences for oral health and disease

Synergistic Effects of Some Methoxyflavones Extracted from Rhizome of Kaempferia parviflora Combined with Gentamicin against Carbapenem-Resistant Strains of Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii

The present study aimed to investigate the antibacterial activity of ethanolic Kaempferia parviflora extracts and the combined effects of the plant’s specific compounds with gentamicin against clinical strains of carbapenem-resistant Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. The minimal inhibitory concentrations (MIC) of gentamicin and Kaempferia parviflora extracts against the tested bacterial strains were determined by using broth microdilution. The combined effects of Kaempferia parviflora extract and gentamicin were investigated by using a checkerboard assay and expressed as a fractional inhibitory concentration index (FICI). Crude ethanolic extract of Kaempferia parviflora showed the lowest median values of MIC towards the tested isolates (n = 10) of these tested bacteria at doses of 64 µg/mL, compared to those of other Kaempferia extracts. Among the isolated compounds, only three compounds, namely 3,5,7-trimethoxyflavone, 3,5,7,3′4′-pentamethoxyflavone, and 5,7,4′-trimethoxyflavone, were identified by NMR structural analysis. According to their FICIs, the synergistic effects of gentamicin combined with 3,5,7,3′4′-pentamethoxyflavone were approximately 90%, 90%, and 80% of tested carbapenem-resistant Klebsiella pneumoniae (CRKP), Pseudomonas aeruginosa (CRPA), and Acinetobacter baumannii (CRAB), respectively. The present study concluded that 3,5,7,3′4′-pentamethoxyflavone extracted from Kaempferia parviflora potentiated the antibacterial action of gentamicin to combat bacterial resistance against the tested bacteria