NODULE ROOT and COCHLEATA Maintain Nodule Development and Are Legume Orthologs of Arabidopsis BLADE-ON-PETIOLE Genes

During their symbiotic interaction with rhizobia, legume plants develop symbiosis-specific organs on their roots, called nodules, that house nitrogen-fixing bacteria. The molecular mechanisms governing the identity and maintenance of these organs are unknown. Using Medicago truncatula nodule root (noot) mutants and pea (Pisum sativum) cochleata (coch) mutants, which are characterized by the abnormal development of roots from the nodule, we identified the NOOT and COCH genes as being necessary for the robust maintenance of nodule identity throughout the nodule developmental program. NOOT and COCH are Arabidopsis thaliana BLADE-ON-PETIOLE orthologs, and we have shown that their functions in leaf and flower development are conserved in M. truncatula and pea. The identification of these two genes defines a clade in the BTB/POZ-ankyrin domain proteins that shares conserved functions in eudicot organ development and suggests that NOOT and COCH were recruited to repress root identity in the legume symbiotic organ.     

The effect on human balance of standing with toe-extension

Background

Postural balance is vital for safely carrying out many daily activities, such as locomotion. The purpose of this study was to determine how changes in normal standing (NS) and standing with toe-extension (SWT) impact postural control during quiet standing. Furthermore, the research aimed to examine the extent to which the effect of these factors differed between genders.

Methodology/Principal Findings

Thirty healthy young adults (age = 21.2±1.3 y; height = 1.63±0.07 m; mass = 56.0±9.3 kg) with no prior lower limb injuries participated in the study. A postural stability test using the Biodex Balance System was used for both NS and SWT conditions. The three measurements from the BBS were Overall Stability Index (OSI), Medial-Lateral Stability Index (MLSI) and Anterior-Posterior Stability Index (APSI). No significant difference was found between NS and SWT in the OSI, MLSI or APSI (F _{2, 28} = 3.357, p = 0.077). The main difference between the stability index scores was significant (F _{2, 28} = 275.1, p<0.001). The Bonferroni post-hoc test showed significant differences between the OSI and MLSI (p<0.001); the OSI and APSI (p<0.001); and the MLSI and the APSI (p<0.001). Significant differences were found during NS (p<0.001), for the MLSI when compared with the APSI, but this was not found during the SWT condition. Additionally, no gender effects were proven to exist that altered postural sway during quiet standing.

Conclusions/Significance

This study reveals significant interaction between the stability indices measured; OSI, APSI and MLSI in both NS and SWT. Standing with toe extended does not have a significant impact on an individual’s ability to control their balance during normal quiet standing. However, the findings revealed that the sway tendency in the medial-lateral direction might serve as a factor in an individual’s ability to regain balance.     

Prevalence and Risk Factors Associated with Entamoeba histolytica/dispar/moshkovskii Infection among Three Orang Asli Ethnic Groups in Malaysia

Background

Entamoeba histolytica/Entamoeba dispar/Entamoeba moshkovskii infection is still prevalent in rural Malaysia especially among Orang Asli communities. Currently, information on prevalence of this infection among different ethnic groups of Orang Asli is unavailable in Malaysia. To contribute to a better comprehension of the epidemiology of this infection, a cross-sectional study aimed at providing the first documented data on the prevalence and risk factors associated with E. histolytica/E. dispar/E. moshkovskii infection was carried out among three Orang Asli ethnic groups (Proto-Malay, Negrito, and Senoi) in selected villages in Negeri Sembilan, Perak, and Pahang states, Malaysia.

Methods/Findings

Faecal samples were examined by formalin-ether sedimentation and trichrome staining techniques. Of 500 individuals, 8.7% (13/150) of Proto-Malay, 29.5% (41/139) of Negrito, and 18.5% (39/211) of Senoi were positive for E. histolytica/E. dispar/E. moshkovskii, respectively. The prevalence of this infection showed an age-dependency relationship, with higher rates observed among those aged less than 15 years in all ethnic groups studied. Multivariate analysis confirmed that not washing hands after playing with soils or gardening and presence of other family members infected with E. histolytica/E. dispar/E. moshkovskii were significant risk factors of infection among all ethnic groups. However, eating with hands, the consumption of raw vegetables, and close contact with domestic animals were identified as significant risk factors in Senoi.

Conclusions

Essentially, the findings highlighted that E. histolytica/E. dispar/E. moshkovskii parasites are still prevalent in Malaysia. Further studies using molecular approaches to distinguish the morphologically identical species of pathogenic, E. histolytica from the non-pathogenic, E. dispar and E. moshkovskii are needed. The establishment of such data will be beneficial for the public health authorities in the planning and implementation of specific prevention and control strategies of this infection in different Orang Asli ethnic groups in Malaysia.     

Effect of environmental stresses on the sensitivity of Enterobacter sakazakii in powdered infant milk formula to gamma radiation

Aim:  To evaluate the effect of starvation, heat, cold, acid, alkaline, chlorine and ethanol stresses on the resistance of Enterobacter sakazakii in powdered infant milk formula (PIMF) towards gamma radiation.
Methods and Results:  Stressed cells of E. sakazakii ATCC 51329 and four other food isolate strains were mixed individually with PIMF, kept overnight at room temperature, and then exposed to gamma radiation up to 7·5 kGy. The D ₁₀-values were determined using linear regression and for the stressed E. sakazakii strains these values ranged from 0·82 to 1·95 kGy.
Conclusions:  Environmental stresses did not significantly change the sensitivity of most E. sakazakii strains to ionizing radiation.
Significance and Impact of the Study:  Data obtained established that most forms of environmental stress are unlikely to significantly enhance the resistance of E. sakazakii strains to lethal, low dose irradiation treatment.     

RAPD typing of Aspergillus chevalieri, Aspergillus nidulans, Aspergillus tetrazonus (quadrilineatus) and their teleomorphs using 5'-d[AACGCGCAAC]-3' and 5'-d[CCCGTCAGCA]-3' primers

Sexuality in fungi has long been a matter of concerns and debates that always necessitated extensive analysis of the relationship between organisms assumed to represent different developmental forms of the same organism. Moreover, mating-virulence correlation and the growing worry of opportunistic fungal infections in immunocompromised states associated with AIDS, cancer chemotherapy and organ transplantation protocols have been critically addressed nowadays. In view of that, we genetically characterized Aspergillus chevalieri, Aspergillus nidulans, Aspergillus tetrazonus (quadrilineatus) and their teleomorphs with RAPD analysis using 5'-d[AACGCGCAAC]-3' and 5'-d[CCCGTCAGCA]-3' primers. The reported similarities between the sexual and the asexual forms of the tested species, using Dice coefficient, ranged between 40% and 70% which holds pretty much with the current systematics of the genus. The study presents a rapid consistent method for identification of A. chevalieri, A. nidulans, A. tetrazonus (quadrilineatus) and their teleomorphs based on the banding pattern of RAPD-generated fragments that can be reliably used ahead of further applications on these species.     

Comparison of PCR fingerprinting techniques for the discrimination of <Emphasis Type="Italic">Salmonella enterica</Emphasis> subsp. <Emphasis Type="Italic">enterica</Emphasis> serovar Weltevreden isolated from indigenous vegetables in Malaysia

Salmonella enterica subsp. enterica (S.) serovar Weltevreden has emerged as a public health problem in many countries. Genomic DNA of S. Weltevreden from indigenous vegetables namely ‘selom’ (Oenanthe stolonifera), ‘pegaga’ (Centella asiatica), ‘kesum’ (Polygonum minus) and ‘kangkong’ (Ipomoea aquatica) were characterized by duplex-polymerase chain reaction (duplex-PCR), multiplex-polymerase chain reaction (multiplex-PCR), random amplified polymorphic DNA (RAPD), enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results demonstrated that a total of four clusters and three single isolates were generated from ERIC-PCR with primers ERIC-1 and ERIC-2 whereas RAPD with arbitrary primers OPAR2, OPAR17 and OPAR19 discriminated the S. Weltevreden into nine clusters and eight single isolates at a common 65% similarity level with discriminatory index (D) of 0.7443 and 0.9394 respectively. Composite analysis of banding profiles generated from RAPD-PCR and ERIC-PCR showed eight clusters and six single isolates at 65% similarity level with the highest D value that is 0.9508. On the other hand, PCR-RFLP and duplex PCR data exhibited a consistent profile for S. Weltevreden. Multiplex-PCR targeting three different antibiotic resistance genes and a common Salmonella specific gene segment produced two distinguishing profiles among the S. Weltevreden examined. These results demonstrated that the combined analysis of RAPD-PCR and ERIC-PCR is a better tool for characterizing S. Weltevreden than individual methods.     

DNA approach to solve clustering problem based on a mutual order

Clustering is regarded as a consortium of concepts and algorithms that are aimed at revealing a structure in highly dimensional data and arriving at a collection of meaningful relationships in data and information granules. The objective of this paper is to propose a DNA computing to support the development of clustering techniques. This approach is of particular interest when dealing with huge data sets, unknown number of clusters and encountering a heterogeneous character of available data. We present a detailed algorithm and show how the essential components of the clustering technique are realized through the corresponding mechanisms of DNA computing. Numerical examples offer a detailed insight into the performance of the DNA-based clustering.     

Thalidomide inhibits epidermal growth factor-induced cell growth in mouse and human monocytic leukemia cells via Ras inactivation

The effect of thalidomide on epidermal growth factor (EGF)-induced cell growth was examined. Thalidomide inhibited EGF-induced cell growth in mouse and human monocytic leukemia cells, RAW 264.7, U937 and THP-1. Thalidomide inhibited EGF-induced phosphorylation of extracellular signal regulated kinase (ERK) 1/2, but not p38 and stress-activated protein kinase (SAPK)/JNK. The phosphorylation of MEK1/2 and Raf at Ser 338 as the upstream molecules of ERK 1/2 was also prevented by thalidomide. Further, it inhibited EGF-induced Ras activation through preventing the transition to GTP-bound active Ras. Thalidomide inhibited the Ras activation induced by lipopolysaccharide (LPS) and vascular endothelial growth factor (VEGF) as well as EGF. There was no significant difference in the expression and function of EGF receptor between thalidomide-treated and non-treated cells. Therefore, thalidomide was suggested to inhibit EGF-induced cell growth via inactivation of Ras.