Degradation of pristine and oxidized single wall carbon nanotubes by CYP3A4

Carbon nanotubes (CNTs) are a class of carbon based nanomaterials which have attracted substantial attention in recent years as they exhibit outstanding physical, mechanical and optical properties. In the last decade many studies have emerged of the underlying mechanisms behind CNT toxicity including malignant transformation, the formation of granulomas, inflammatory responses, oxidative stress, DNA damage and mutation. In the present investigation, we studied the biodegradation of single-walled carbon nanotubes (SWCNTs) by Cytochrome P450 enzymes (CYP3A4) through using Raman spectroscopy. CYP3A4 is known isozyme accountable for metabolizing various endogenous and exogenous xenobiotics. CYP3A4 is expressed dominantly in the liver and other organs including the lungs. Our results suggest that CYP3A4 has a higher affinity for p-SWNTs compared to c-SWNTs. HEK293 cellular viability was not compromised when incubated with SWNT. However, CYP3A4 transfected HEK293 cell line showed no digestion of c-SWNTs after incubation for 96 h. Cellular uptake of c-SWNTs was observed by electron microscopy and localization of c-SWNTs was confirmed in endosomal vesicles and in the cytoplasm. This is the first study CYP3A4 degrading both p-SWNTs and c-SWNTs in an in vitro setup. Interestingly, our results show that CYP3A4 is more proficient in degrading p-SWNTs than c-SWNTs. We also employed computational modeling and docking assessments to develop a further understanding of the molecular interaction mechanism.

Development and validation of TaqMan real-time PCR for the detection of Burkholderia pseudomallei isolates from Malaysia

Rapid detection of Burkholderia pseudomallei, the etiologic agent of melioidosis, allows for timely initiation of appropriate treatment and better clinical outcomes. In the current gold standard, the culture method is time consuming and suffers from low sensitivity. Meanwhile, previously reported molecular assays are fast and sensitive, but their performance on isolates from Malaysia, an endemic region of melioidosis is under reported. This study designed oligonucleotides targeting orf2 of Type III secretion system (TTSS) genes cluster for the detection of Malaysian B. pseudomallei isolates and evaluated the assay on 95 local B. pseudomallei strains, 58 other microorganisms and 71 clinical specimens from patients. The developed assay exclusively detected all tested B. pseudomallei isolates with a detection limit of 20 fg per reaction (equivalent to ~2.5 copies). Subsequent testing on clinical samples showed that the assay detected all confirmed specimens with the growth of B. pseudomallei (n = 10/10). None of the negative specimens had a detectable signal of our TTSS-orf2 assay (n = 0/61). In conclusion, the present study provides crucial preliminary data for a subsequent study and should be considered as a potential alternative to current time-consuming culture method for the detection of B. pseudomallei.

New Routes for Novel Pyrazolo[3,4-b][1,6]-naphthyridine, Pyrazolo[3,4-b]pyridine and Pyrazolo[3,4:2,3]pyrido[6,1-a]benzimidazole Derivatives

Pyrazolo[3,4- b] [1,6] naphthyridine, pyrazolo[3,4- b] pyridine and pyrazolo[3,4:2,3] pyrido [6,1 -a] benzimidazole derivatives are synthesized starting from the isomeric 3-substituted 5-chloro-1-phenylpyrazole-4-carbaldehyde.

Facilitating patient-centered care: the development of illustrated multidimensional patient-reported outcome measures for children/adolescents with juvenile idiopathic arthritis

OBJECTIVES

To assess the validity, reliability, comprehensibility, and responsiveness to change of an illustrated child/parent multidimensional patient-reported outcome measures (PROMs) questionnaire which can assess construct outcome measures of children with juvenile inflammatory arthritis.

METHODS

A total of 122 children with juvenile idiopathic arthritis were included in this work in a multicenter study. The questionnaire included seven categories: (1) functional ability; (2) health-related quality of life; (3) disease activity measures: pain, global assessment, fatigue, and morning stiffness; (4) self-reported joint tenderness; (5) current medication, side effects, and adherence to therapy; (6) comorbidities; and (7) patient motivation. All the items were supported by illustrations to provide children with a visual impression of what was meant by the questions. The questionnaire has parent and patient versions. The disease activity status was assessed using JADAS-27.

RESULTS

The questionnaire was reliable as demonstrated by a high-standardized alpha (0.890-0.978). The questionnaire items correlated significantly (p < 0.01) with clinical parameters of disease activity. The patient-reported tender joints correlated significantly with the physician's scores (0.842). Changes in functional disability, quality of life, and the motivation score showed significant variation (p < 0.01) with disease activity status in response to therapy. The illustrated PROMs questionnaire showed also a high degree of comprehensibility (9.6).

CONCLUSIONS

Integrating PROMs into standard clinical practice is feasible and applicable. The illustrated questionnaire was valid and reliable. It provides an informative, quantitative measure for the disease activity score set data, and in the meantime, facilitates the assessment of the children's adherence to therapy, comorbidities, and motivation on an individual basis.

Cortical recruitment and functional dynamics in postural control adaptation and habituation during vibratory proprioceptive stimulation

OBJECTIVE

Maintaining upright posture is a complex task governed by the integration of afferent sensorimotor and visual information with compensatory neuromuscular reactions. The objective of the present work was to characterize the visual dependency and functional dynamics of cortical activation during postural control.

APPROACH

Proprioceptic vibratory stimulation of calf muscles at 85 Hz was performed to evoke postural perturbation in open-eye (OE) and closed-eye (CE) experimental trials, with pseudorandom binary stimulation phases divided into four segments of 16 stimuli. 64-channel EEG was recorded at 512 Hz, with perturbation epochs defined using bipolar electrodes placed proximal to each vibrator. Power spectra variation and linearity analysis was performed via fast Fourier transformation into six frequency bands (Δ, 0.5-3.5 Hz; θ, 3.5-7.5 Hz; α, 7.5-12.5 Hz; β, 12.5-30 Hz; [Formula: see text], 30-50 Hz; and [Formula: see text], 50-80 Hz). Finally, functional connectivity assessment was explored via network segregation and integration analyses.

MAIN RESULTS

Spectra variation showed waveform and vision-dependent activation within cortical regions specific to both postural adaptation and habituation. Generalized spectral variation yielded significant shifts from low to high frequencies in CE adaptation trials, with overall activity suppressed in habituation; OE trials showed the opposite phenomenon, with both adaptation and habituation yielding increases in spectral power. Finally, our analysis of functional dynamics reveals novel cortical networks implicated in postural control using EEG source-space brain networks. In particular, our reported significant increase in local θ connectivity may signify the planning of corrective steps and/or the analysis of falling consequences, while α band network integration results reflect an inhibition of error detection within the cingulate cortex, likely due to habituation.

SIGNIFICANCE

Our findings principally suggest that specific cortical waveforms are dependent upon the availability of visual feedback, and we furthermore present the first evidence that local and global brain networks undergo characteristic modification during postural control.

PI3K/Akt and Nrf2/HO-1 pathways involved in the hepatoprotective effect of verapamil against thioacetamide toxicity in rats

Liver is a precious organ to maintain body life. Hepatotoxicity is a worldwide health problem that is still a challenge for research. Although countless pharmaceutical drugs and herbal compounds were screened for their hepatoprotective effects, the death from hepatotoxicity is increasing. Thus, there is continuous necessity of searching for the hepatoprotective effect of commonly used drugs. Accordingly, our aim was to examine a hepatoprotective potential for the antihypertensive drug, verapamil, and searching for new insights underlie its protective mechanism. Four groups of adult male rats were randomly arranged as controls, thioacetamide (TAA) hepatotoxic, and TAA + verapamil treated. Serum liver enzyme, hepatic antioxidant, lipid peroxidation, and inflammatory parameters were assessed. Gene relative expression for heme oxygenase-1 (HO-1), nuclear factor-erythroid 2-related factor 2 (Nrf2), phosphoinositide 3-kinase (PI3K), and serine/threonine-specific protein kinase (Akt) were quantified in hepatic tissue. TAA caused hepatic injury evident both histopathologically and biochemically by a decrease in all gene expressions. Verapamil alleviated the injury via its antioxidant and anti-inflammatory effects that were suggested to be via upregulation of the previous gene expressions. In conclusion, the calcium channel blocker, verapamil, that is used widely as antihypertensive exhibits a valuable hepatoprotective effect. The protection partially rests on activation of Nrf2/HO-1 and PI3K/Akt pathways.

Perception and utilization of tetanus toxoid immunization among pregnant women attending a tertiary centre in North-West Nigeria

Background: Despite the availability of inexpensive and effective tetanus-toxoid-containing vaccines, elimination of maternal and neonatal tetanus worldwide has become a herculean task, particularly in low-income countries, due to poor immunization coverage. This study aimed to assess the perception and utilization of tetanus toxoid immunization among pregnant women attending a tertiary centre in North-West Nigeria. Materials and Methods: A cross-sectional study was conducted among 254 pregnant women (selected by systematic sampling technique) attending the antenatal clinic of Specialist Hospital, Sokoto, Nigeria. A structured interviewer-administered questionnaire was used to collect data on the research variables. Data were analyzed using IBM SPSS version 20 statistical computer software package. Results: Most, 221 (87.0%) of the 254 respondents had heard of tetanus toxoid immunization. Of these, only about half (51.1%) believed that it protects both mother and newborn baby from tetanus. Majority of respondents considered TT immunization to be effective in protecting against tetanus infection (73.3%) and also safe for both mother and baby (79.2%). About two-thirds of respondents (68.8%) had the misconception that a single dose of TT immunization protects from tetanus infection. Less than a quarter of respondents (23.6%) had received two or more doses of the vaccine. The main barriers to utilization of vaccines were lack of awareness of the vaccine (41.8%), not being aware of its benefits (36.7%), and fear of side effects (21.5%) Conclusion: Despite high levels of perception of the effectiveness and safety of TT immunization, the respondents in this study had low levels of perception and utilization of the protective doses of the vaccine. Government and healthcare workers should scale-up education of the populace on TT immunization schedule and implement community based vaccination of women of child bearing age in North-West Nigeria. Keywords: Perception, utilization, tetanus toxoid immunization, pregnant women

Finding Novel Anti-carcinomas Compounds by Targeting SFRP4 Through Molecular Modeling, Docking and Dynamic Simulation Studies

BACKGROUND

Secreted Frizzled-Related Protein 4 (SFRP4) is a glycoprotein that acts as a competitor of both canonical and non-canonical Wnt pathways. SFRP4 is mostly expressed in ovary and plays a significant role as a target molecule to cure ovarian carcinoma.

OBJECTIVE

Multiple chemical agonists are being used to cure ovary melanoma. We are interested in theoretically analyzing the compounds through computational approaches for their potential inhibitory effects against SFRP4.

METHODS

Compounds were sketched in Chemsketch drawing tool and minimized through chimera tool. Because the crystal structure of SFRP4 is not available in Protein Data Bank, homology modeling approach was used to predict Three-Dimensional (3D) crystal structure of SFRP4. Moreover, multiple computational approaches such as molecular docking and Molecular Dynamic (MD) simulations along with various online tools were employed to screen the best inhibitor against ovary melanoma.

RESULTS

The docking results showed that 1d and 1e compounds revealed significant binding energy values (-9.10 and -9.00 kcal/mol, respectively) compared with the standard drugs such as cis-platin and docetaxel (-3.30, -10.80 kcal/mol), respectively. Moreover, MD simulation results showed that 1d has little fluctuations throughout the simulation period as depicted by the root mean square deviation and root mean square fluctuation graphs.

CONCLUSION

The present in-silico study provides a deeper insight into the structural attributes of 1d compound and its overall molecular interactions against SFRP4 and gives a hypothetical gateway to use this compound as a potential inhibitor against ovarian carcinoma.

Dynamic reshaping of functional brain networks during visual object recognition

OBJECTIVE

Emerging evidence shows that the modular organization of the human brain allows for better and efficient cognitive performance. Many of these cognitive functions are very fast and occur in a sub-second time scale such as the visual object recognition.

APPROACH

Here, we investigate brain network modularity while controlling stimuli meaningfulness and measuring a participant's reaction time. We particularly raised two questions: i) does the dynamic brain network modularity change during the recognition of meaningful and meaningless visual images? And (ii) is there a correlation between network modularity and the reaction time of the participants? To tackle these issues, we collected dense-electroencephalography (EEG, 256 channels) data from 20 healthy human subjects performing a cognitive task consisting of naming meaningful (tools, animals…) and meaningless (scrambled) images. Functional brain networks in both categories were estimated at the sub-second time scale using the EEG source connectivity method. By using multislice modularity algorithms, we tracked the reconfiguration of functional networks during the recognition of both meaningful and meaningless images.

MAIN RESULTS

Results showed a difference in the module's characteristics of both conditions in term of integration (interactions between modules) and occurrence (probability on average of any two brain regions to fall in the same module during the task). Integration and occurrence were greater for meaningless than for meaningful images. Our findings revealed also that the occurrence within the right frontal regions and the left occipito-temporal can help to predict the ability of the brain to rapidly recognize and name visual stimuli.

SIGNIFICANCE

We speculate that these observations are applicable not only to other fast cognitive functions but also to detect fast disconnections that can occur in some brain disorders.