Different Clinical Outcomes of Entamoeba histolytica in Malaysia: Does Genetic Diversity Exist?

The present study was conducted to investigate the clinical outcomes of Entamoeba histolytica infection in symptomatic and asymptomatic Orang Asli (aborigine) communities in Malaysia. Examination was performed on 500 stool samples obtained from Orang Asli communities in 3 different states using formalin-ether concentration, trichrome staining, and single-round PCR techniques. Out of 500 stool samples, single infection of E. histolytica, Entamoeba dispar, and Entamoeba moshkovskii was identified in 3.2%, 13.4%, and 1%, respectively. In addition, 10 samples had mixed infections with E. histolytica and E. dispar. Six samples containing E. dispar were also positive for E. moshkovskii, and only 2 samples had E. histolytica in association with E. dispar and E. moshkovskii. Seventeen E. histolytica-positive samples were from symptomatic subjects, whereas the remaining 11 samples came from asymptomatic subjects. These findings suggest a predominant distribution of pathogenic potential of E. histolytica strains in this community. Therefore, further studies on genotyping of E. histolytica is required, to find out association between E. histolytica genotype and the outcome of the infection.     

Experimental Characterization of the Chronic Constriction Injury-Induced Neuropathic Pain Model in Mice

Number of ligations made in the chronic constriction injury (CCI) neuropathic pain model has raised serious concerns. We compared behavioural responses, nerve morphology and expression of pain marker, c-fos among CCI models developed with one, two, three and four ligations. The numbers of ligation(s) on sciatic nerve shows no significant difference in displaying mechanical and cold allodynia, and mechanical and thermal hyperalgesia throughout 84 days. All groups underwent similar levels of nerve degeneration post-surgery. Similar c-fos level in brain cingulate cortex, parafascicular nuclei and amygdala were observed in all CCI models compared to sham-operated group. Therefore, number of ligations does not impact intensity of pain symptoms, pathogenesis and neuronal activation. A single ligation is sufficient to develop neuropathic pain, in contrast to the established model of four ligations. This study dissects and characterises the CCI model, ascertaining a more uniform animal model to surrogate actual neuropathic pain condition.

     

Living arrangement and life satisfaction in older malaysians: the mediating role of social support function

Background

This cross-sectional and correlational survey examines the association between different types of living arrangements and life satisfaction in older Malaysians, while taking into account the mediating effects of social support function.

Methodology and Findings

A total of 1880 of older adults were selected by multistage stratified sampling. Life satisfaction and social support were measured with the Philadelphia Geriatric Center Morale Scale and Medical Outcomes Study Social Support Survey. The result shows living with children as the commonest type of living arrangement for older adults in peninsular Malaysia. Compared to living alone, living only with a spouse especially and then co-residency with children were both associated with better life satisfaction (p<.01) and social support function (p<.01). The mediating effect of social support function enhanced the relation between living arrangements and life satisfaction.

Conclusion

This study revealed that types of living arrangement directly, and indirectly through social support function, play an important role in predicting life satisfaction for older adults in Malaysia. This study makes remarkable contributions to the Convoy model in older Malaysians.     

Cytokine-mediated differential regulation of macrophage activator protein-1 genes

The regulation of macrophage activator protein-1 (AP-1) gene expression by LPS and cytokines is of potentially crucial importance in the pathogenesis of several diseases. The action of LPS and four cytokines on AP-1 gene expression in the murine macrophage J774.2 cell line was, therefore, studied. Exposure of the cells to IL-6 produced no changes in the mRNA levels of all AP-1 members studied. In contrast, the expression of JunB, c-jun and c-fos, but not JunD, was increased by LPS, TNF-alpha, IFN-gamma and IL-1, albeit with different kinetics and magnitude of induction. Electrophoretic mobility shift assays showed a close correlation between the expression of the AP-1 genes and the functional AP-1 DNA binding activity and, additionally, demonstrated the participation of heterodimeric interactions between the different members. These studies provide insights into the potential mechanisms that may be involved in the mediator-specific modulation of AP-1 regulated macrophage gene expression.     

High regeneration rates in anther culture of interspecific sunflower hybrids

Optimization of anther culture with regard to the induction of callus formation and direct embryogenesis was obtained for interspecific hybrids ofH. annuus withH. tuberosus, H. laetiflorus, andH. resinosus by investigating six different induction media and four regeneration media. One media combination (MS-13, MS-R3 and MS-R4) used under different culture conditions (30°C / 35°C and different dark treatments) gave up to 92.7% embryogenic anthers with an average of 8.5 embryos per anther. However, direct embryogenesis as well as callus formation showed a strong genotypec and treatment specific reaction. From 5,600 anthers of the four investigated genotypes more than 2,000 plants could be regenerated. Regenerants were characterized by morphological traits and isozyme analyses to prove their androgenetic origin.     

In vitro effects of multi-purpose contact lens disinfecting solutions towards survivability of Acanthamoeba genotype T4 in Malaysia

The incidence of Acanthamoeba keratitis has been increasing since the previous decades, especially among contact lens users. This infection is majorly caused by the use of ineffective contact lens disinfecting solution. Thus, this study was conducted to evaluate the in vitro effects of multi-purpose disinfecting solutions (MPDS) against Acanthamoeba trophozoites and cysts. Acanthamoeba genotype T4 isolated from contact lens paraphernalia and an environmental strains were propagated for trophozoite or cyst-containing culture and adjusted in final concentration of 1 × 10⁵ cells/ml. Amoebicidal and cysticidal assays were conducted by incubating trophozoites and cysts with OPTI-FREE® Express®, ReNu® Fresh™, Complete® Multi-Purpose Solution and AVIZOR Unica® Sensitive according to the manufacturer’s minimum recommended disinfectant time (MMRDT) for up to 12 h at 30 ⁰C. Trypan blue hemocytometer-based microscopic counts determined amoebicidal and cysticidal effects. The viability of Acanthamoeba trophozoites and cysts was confirmed by re-inoculated them in the 1.5% non-nutrient agar plates. It was found that none of the MPDS showed amoebicidal and cysticidal effects during the MMRDT. However, OPTI-FREE® Express® demonstrated a significant differences in average cell reduction for both stages within MMRDT. When subjected to 12 h exposure, both OPTI-FREE® Express® and ReNu® Fresh™ led to significant reduction in the number of trophozoite and cyst cells. Notably, Complete® Multi-Purpose Solution and AVIZOR Unica® Sensitive did appreciably improve the solution effectiveness towards trophozoite cells when incubated for 12 h. All MPDS were largely ineffective, with 100% survival of all isolates at MMRDT, while OPTI-FREE® Express® showed limited amoebicidal activity against the contact lens paraphernalia isolate, however, it was more against the environmental strains after 12 h incubation time. The commercially available MPDS employed in this research offered minimal effectiveness against the protozoa despite the contact time. Improvement or development of new solution should consider the adjustment of the appropriate disinfectant concentration, adequate exposure time or the incorporation of novel chemical elements, which are effective against Acanthamoeba for accelerated disinfecting and more reduction of potential exposure of contact lens users to Acanthamoeba keratitis.     

Andrographolide and 14-deoxy-11, 12-didehydroandrographolide inhibit cytochrome P450s in HepG2 hepatoma cells

AimsCytochrome P450 (CYP) enzymes have been implicated in a large number of preventable drug–herb interactions. Andrographis paniculata Nees, a tropical herb widely used for various health conditions contains two major diterpenoids, andrographolide and 14-Deoxy-11, 12-Didehydroandrographolide. These compounds were evaluated systematically for their effects on CYP1A2, CYP2D6 and CYP3A4 expressions in HepG2 cells.Main methodsQuantitative RT-PCR and Western blot analysis were used to assess the mRNA and protein expression of the three CYPs. CYP3A4 enzyme activity was evaluated using P450-Glo? Assays. The LanthaScreen® TR-FRET PXR (SXR) Competitive Binding Assay was used to determine if the compounds are potential PXR-ligands.Key findingsBoth diterpenoids inhibited the mRNA and protein expressions of CYP1A2, CYP2D6, and CYP3A4. Interestingly, the lowest concentration of both diterpenoids produced a more than 50% reduction in the mRNA and protein expression of CYP3A4 and this reduction was consistent with the enzyme activity. Further experiments revealed that both diterpenoids were also capable of attenuating the ability of dexamethasone to induce CYP3A4 expression, and 14-Deoxy-11, 12-Didehydroandrographolide tended to bind to the PXR-LBD site in a concentration-dependent manner.SignificanceThese diterpenoids are potential CYP3A4 inhibitors and the effects on CYP3A4 may be clinically significant. 14-Deoxy-11, 12-Didehydroandrographolide inhibits CYP3A4 by binding and antagonizing PXR function.     

Assessment of factors influencing morale in the elderly

Background

We examined the relationship between morale measured by the Philadelphia Geriatric Morale Scale (PGC) and disability, social support, religiosity, and personality traits. Instruments predicting morale were then tested against PGC domains.

Methods

The study utilized a cross-sectional survey with a multistage cluster sampling design. Instruments used were disability (disease burden; WHO Disability Score-II, WHODAS-II), social support (Duke Social Support Scale, DUSOCS; Lubben Social Network Scale, LSNS-6; Medical Outcomes Study Social Support Survey, MOS-SSS), religiosity (Revised Intrinsic-Extrinsic Religious Orientation Scale, I/E-R), and personality (Ten-Item Personality Inventory, TIPI). These were plotted as bar charts against PGC, resolved with one-way ANOVA and Kruskal-Wallis tests, then corrected for multiple comparisons. This process was repeated with PGC domains. Contribution of factors was modeled using population attributable risk (PAR) and odds ratios. Effect of confounders such as gender, age, and ethnicity were checked using binary logistic regression.

Results

All instruments showed clear relationships with PGC, with WHODAS-II and DUSOCS performing well (ANOVA p<0.001). For PGC domains, attitude toward aging and lonely dissatisfaction trended together, while agitation did not. PAR, odds ratios, and Exp(β) were disability (WHODAS-II: 28.5%, 3.8, 2.8), social support (DUSOCS: 28.0%, 3.4, 2.2), religiosity (I/E-R: 21.6%, 3.2, 2.1), and personality (TIPI: 27.9%, 3.6, 2.4). Combined PAR was 70.9%.

Conclusions

Disability, social support, religiosity, and personality strongly influence morale in the elderly. WHODAS-II and DUSOCS perform best in measuring disability and social support respectively.