Experimental and pharmacoinformatic approaches unveil the neuropharmacological and analgesic potential of chloroform fraction of Roktoshirinchi (Achyranthes ferruginea Roxb.)

ETHNOPHARMACOLOGICAL RELEVANCE

Achyranthes ferruginea (A. ferruginea) Roxb. is a common plant used in traditional medicine in Asia and Africa. It has a variety of local names, including "Gulmanci" in Nigeria, "Dangar" in Pakistan, "Thola" in Ethiopia, and "Roktoshirinchi" in Bangladesh. It is edible and has several ethnomedical uses for a wide range of illnesses, including hysteria, dropsy, constipation, piles, boils, asthma, and shigellosis. However, the neuropharmacological and analgesic potential of A. ferruginea remains uninvestigated.

AIM OF THE STUDY

To assess the neuropharmacological and analgesic potential of A. ferruginea through a multifaceted approach encompassing both experimental and computational models.

MATERIALS AND METHODS

Methanol was used to extract the leaves of A. ferruginea. It was then fractionated with low to high polar solvents (n-hexane, chloroform, ethyl acetate, and water) to get different fractions, including chloroform fraction (CLF). The study selected CLF at different doses and conducted advanced chemical element and proximate analyses, as well as phytochemical profiling using GC-MS. Toxicological studies were done at 300 μg per rat per day for 14 days. Cholinesterase inhibitory potential was checked using an in-vitro colorimetric assay. Acetic acid-induced writhing (AAWT) and formalin-induced licking tests (FILT) were used to assess anti-nociceptive effects. The forced swim test (FST), tail suspension test (TST), elevated plus maze (EPM), hole board test (HBT), and light and dark box test (LDB) were among the behavioral tests used to assess depression and anxiolytic activity. Network pharmacology-based analysis was performed on selected compounds using the search tool for interacting chemicals-5 (STITCH 5), Swiss target prediction tool, and search tool for the retrieval of interacting genes and proteins (STRING) database to link their role with genes involved in neurological disorders through gene ontology and reactome analysis.

RESULTS

Qualitative chemical element analysis revealed the presence of 15 elements, including Na, K, Ca, Mg, P, and Zn. The moisture content, ash value, and organic matter were found to be 11.12, 11.03, and 88.97%, respectively. GC-MS data revealed that the CLF possesses 25 phytoconstituents. Toxicological studies suggested the CLF has no effects on normal growth, hematological and biochemical parameters, or cellular organs after 14 days at 300 μg per rat. The CLF markedly reduced the activity of both acetylcholinesterase and butyrylcholinesterase (IC50: 56.22 and 13.22 μg/mL, respectively). Promising dose-dependent analgesic activity (p < 0.05) was observed in chemically-induced pain models. The TST and FST showed a dose-dependent substantial reduction in immobility time due to the CLF. Treatment with CLF notably increased the number of open arm entries and time spent in the EPM test at doses of 200 and 400 mg/kg b.w. The CLF showed significant anxiolytic activity at 200 mg/kg b.w. in the HBT test, whereas a similar activity was observed at 400 mg/kg b.w. in the EPM test. A notable increase in the amount of time spent in the light compartment was observed in the LDB test by mice treated with CLF, suggesting an anxiolytic effect. A network pharmacology study demonstrated the relationship between the phytochemicals and a number of targets, such as PPARA, PPARG, CHRM1, and HTR2, which are connected to the shown bioactivities.

CONCLUSIONS

This study demonstrated the safety of A. ferruginea and its efficacy in attenuating cholinesterase inhibitory activity, central and peripheral pain, anxiety, and depression, warranting further exploration of its therapeutic potential.

Cold indoor temperatures and their association with health and well-being: a systematic literature review

OBJECTIVE

The study aimed to identify, appraise and update evidence on the association between cold temperatures (i.e. <18°C) within homes (i.e. dwellings) and health and well-being outcomes.

STUDY DESIGN

This study was a systematic review.

METHODS

Seven databases (MEDLINE, Embase, Cochrane Database of Systematic Reviews, CINAHL, APA PsycInfo, Applied Social Sciences Index and Abstracts, Coronavirus Research Database) were searched for studies published between 2014 and 2022, which explored the association between cold indoor temperatures and health and well-being outcomes. Studies were limited to those conducted in temperate and colder climates due to the increased risk of morbidity and mortality during winter in those climatic zones. Studies were independently quality assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies.

RESULTS

Of 1209 studies, 20 were included for review. Study outcomes included cardiovascular (blood pressure, electrocardiogram abnormalities, blood platelet count), respiratory (chronic obstructive pulmonary disease symptoms, respiratory viral infection), sleep, physical performance and general health. Seventeen studies found exposure to cold indoor temperatures was associated with negative effects on health outcomes studied. Older individuals and those with chronic health problems were found to be more vulnerable to negative health outcomes.

CONCLUSION

Evidence suggests that indoor temperatures <18°C are associated with negative health effects. However, the evidence is insufficient to allow clear conclusions regarding outcomes from specific temperature thresholds for different population groups. Significant gaps in the current evidence base are identified, including research on the impacts of cold indoor temperatures on mental health and well-being, studies involving young children, and the long-term health effects of cold indoor temperatures.

Persistence with macitentan versus other endothelin receptor antagonists in patients with pulmonary arterial hypertension: experience from a real-world data repository in the USA

Background

Pulmonary arterial hypertension (PAH) is a progressive and fatal disease and as such, it is imperative that patients remain on therapy to delay progression and maintain functional status. Previous research has demonstrated differences in overall survival in the real-world by endothelin receptor antagonists (ERA) treatments with a lower risk of death with macitentan than ambrisentan and bosentan. However, real-world data on persistence to ERAs are limited.

Purpose

To compare persistence to macitentan versus ambrisentan and bosentan) in patients with PAH.

Methods

This retrospective, non-interventional, observational study identified patients between 10/21/2013–3/31/2021 (study period) from the Decision Resources Group (DRG) Real World Data Repository. The repository links medical and prescription claims from commercial, Medicaid, and Medicare plans with electronic health records (EHRs) to provide longitudinal patient-level data representative of over 300 million patients in the US. Patients selected must have been dispensed an ERA prescription from 4/14/14–3/31/20 AND 1) either an inpatient diagnosis of pulmonary hypertension (PH), or 2) a right heart catheterization with any PH diagnosis, or 3) were taking a phosphodiesterase 5 inhibitor (PDE5i). The primary outcome was persistence defined by time from index to drug discontinuation (90-day gap after the end of the last prescription's days of supply). Descriptive analysis comprised means, standard deviations, medians, and interquartile ranges for continuous variables and frequencies and percentages for categorical variables. Three-sample proportion tests were conducted at baseline to detect differences between the three cohorts and identify potentially confounding variables. Hazard ratios (HR) for pairwise comparisons (macitentan vs ambrisentan; macitentan vs bosentan) were calculated using an inverse probability of treatment weighting (IPTW)-adjusted Cox proportional regression model, to adjust for potential confounders (see Table 1) of the probability of receiving a specific ERA. Data were analyzed by Kaplan-Meier method.

Results

A total of 4,526 patients were included, of whom 1,205 received macitentan, 2,592 received ambrisentan and 729 received bosentan. Study population characteristics were representative of a general PAH population (Table 1). Unadjusted Kaplan-Meier analysis showed that median persistence was shortest for ambrisentan (12.6 months) followed by bosentan (13.6 months) and greatest for macitentan (15.8 months; overall log-rank p-value: 0.061). Compared to macitentan, patients on other ERAs had a greater risk of discontinuation: ambrisentan (10%) and bosentan (18%) (Table 2).

Conclusions

Persistence to therapy was significantly greater for macitentan-treated patients than in those receiving ambrisentan or bosentan. Further research examining variability in key sub-groups as well as the impact of improved persistence on long-term outcomes is warranted.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Janssen Scientific Affairs, LLC

The Health and wellbeing impacts of Home and agile working in Wales: A HIA Approach

The SARS-COV-02 pandemic has globally resulted in a number of policies and interventions to address and reduce the transmission of the disease throughout the population. Mitigation measures have ranged from ‘Staying at Home' or ‘Lockdowns' to social distancing policies and requirements to work from home when you can. Whilst there are a number of papers which discuss the effects of home or remote working on employees and their families the large scale shift, accelerated pace and wider impacts of such a shift has not been well explored in the literature or has been focussed on specific topics, for example, productivity. HIA is promoted as a beneficial tool to identify the wider impacts of a policy, plan or intervention across a population and as such is well placed to examine and articulate who in a population may be affected and how, and the inequalities that may be created by an intervention such as home working. Using the lens of social determinants and equity focussed-HIA, this work examines the wider impact of home working in Wales during the COVID-19 pandemic. It provides a coherent overview of the major impacts on health and the particular populations affected. It articulates the process followed, the key evidence based findings, discusses the gaps in the evidence base that require further exploration and the impact and influence it has had to date. Finally, it shares the transferable learning, which will be of use to researchers, policy and decision makers, organisations and public health agencies.

A mixed methods study of lived experiences of homelessness in Wales and childhood adversity

Background

Homelessness is a serious and complex societal and public health issue with multiple causes and solutions. Dealing with homelessness involves both supporting people at risk of homelessness and addressing personal and structural causes occurring through the life-course, including Adverse Childhood Experiences (ACEs). We examine the relationship between ACEs and homelessness in Wales, and consider priority areas for early intervention and prevention.

Methods

Data was retrospectively analysed from a 2017 cross-sectional national 2017 (n = 2452) of adults aged 16-69 years living in Wales using a stratified random probability sampling methodology. Outcome measures included number of ACEs, lifetime homelessness, and childhood resilience assets and were analysed using bivariate statistics. Pathways interviews with people experiencing homelessness (n = 27) and services (n = 16) explored experiences and views, and were analysed thematically.

Results

Homelessness affects 1 in 14 (7%) of the Welsh population in their lifetime. 87% of those with lived experience of homelessness had experienced at least one ACE compared with a Welsh average of 46%; and 50% of those with lived experience of homelessness had experienced 4+ ACEs, compared to 11% in the wider population. Compared with those with no ACEs, individuals with 4+ ACEs were 16 times more likely to report experiencing homelessness (95% CI 9.73,26.43), but Childhood Resilience Assets were protective reducing this by half (adjusted odds ratio 8.073, 95% CI 4.68,13.93). From interviews, early years/schools are critical in supporting children with ACEs, and services through the life-course need to be ACE-aware and better able to cope with impacts of ACEs.

Conclusions

A clear association is seen between ACEs and homelessness. Early intervention that prevents ACEs is needed, as well as better addressing support needs of both child and adult vulnerable populations to prevent homelessness and intervene earlier.

Key messages

In a national Welsh study, 87% of those reporting lived experience of homelessness had experienced at least one adverse childhood experience (ACE), and 50% reported four or more ACEs. Early intervention that prevents ACEs, combined with a trauma-informed approach that builds resilience in at-risk children and adults, is likely to contribute to reducing and preventing homelessness.

184 Effects of The Coronavirus Pandemic on Medical and Surgical Education: Results of An International Survey by The International Association of Student Surgical Societies (IASSS)

Aim

Coronavirus disease 2019 (COVID-19) presents a variety of unforeseen challenges to medical students and surgical trainees. Adaptations to the content and delivery of medical education are inevitable as institutions respond to the virus. Departments face significant restructuring, with important implications for training. Our aim was to assess the global impact of the first wave of COVID-19 on medical and surgical education.

Method

Between 12 May and 26 May 2020, an online survey was conducted and circulated to contacts of the International Association of Student Surgical Societies, including medical students and healthcare practitioners. All data were anonymous; no personal identifiable information was collected. Consent was implied by participation in the survey, which was on a voluntary basis.

Results

We collated 527 responses from 111 institutions across 26 countries. Globally, 93.5% of medical student placements were affected by the first wave of COVID-19, with examination restructuring and alternative teaching methods employed by 87.8% of medical schools. Trainee redeployment was common in both surgical (61.5%) and non-surgical (77.1%) disciplines. Surgical services were significantly affected, with reduced elective procedures in 93% of institutions. On an individual level, COVID-19 resulted in prolonged absence from clinical duties and mental health concerns at all levels of training.

Conclusions

Our data highlight drastic changes in medical and surgical education and practice as a result of the first wave of COVID-19. These changes are significant at all levels of training, both institutionally and individually. The pandemic is likely to have persistent consequences for future trainees in terms of education and career progression.

E. coli expression and immunological assessment of expressed recombinant Newcastle disease virus hemagglutinin-neuraminidase protein in chickens

Every year, the poultry industry experiences significant economic losses due to epidemics of Newcastle disease virus (NDV). Developing new vaccines by identifying and using the immunogenic hemagglutinin-neuraminidase (HN) protein can protect the poultry industry. In the present study, the full-length HN protein was expressed in Escherichia coli (E. coli) BL21 (DE3) cells, purified via affinity chromatography and detected via western blot analysis using His-specific antibodies. The purified HN protein was further evaluated in chickens to study the immune response against NDV. The successful production of HN-specific IgY proved the activity of the purified HN protein. IgY was present in the serum of immunized chickens. However, the immune response was higher in chickens immunized with purified HN protein along with complete and incomplete adjuvants than in chickens immunized with only the HN protein. Keywords: protein; Newcastle disease virus; poultry; infectious diseases; vaccines.

A ‘futures’ approach towards the wellbeing of future generations in Wales and beyond

'Futures' is a way of thinking about future uncertainty. It is not about predicting the future but is about developing alternative futures or scenarios and using them to inform how best to move towards the preferred future. This approach has been explored and applied to Wales, the UK, which has the Well-being of Future Generations (Wales) Act 2015. This Act has been globally recognised as a unique sustainable development legislation, putting Wales at the forefront of creating a different future for generations to come. Whilst most public bodies have always had responsibilities in delivering a range of services to support health and wellbeing, one of the key innovative requirements of the Act is the focus on the 'future', which by definition requires new and different approaches. This in turn means new tools, new skills and a new and different mind-set in which planners, commissioners, policy makers and service providers need to take a long-term view to addressing health and well-being. The presentation will explore the various approaches, methods and tools for 'futures' thinking and how this innovative agenda is progressing in Wales.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Clinical profile of nonsmall cell lung carcinoma patients treated in a single unit at a tertiary cancer care center

BACKGROUND

Recent advances and understanding in the field of lung cancer and advent of newer treatments have shown a significant improvement in survival in the patients. The present study was conducted to analyze the clinical profile of nonsmall cell lung cancer (NSCLC) patients treated in a single unit at a tertiary cancer care center.

MATERIALS AND METHODS

In this retrospective analysis, 322 consecutive NSCLC patients from the year 2011 to 2012 treated in a single unit were included in the study. Patients with proven NSCLC were included in the study. The details of the patients included the demographic profile, pathological diagnosis as well as imaging data, tumor profile, details of treatment, and follow-up information.

RESULTS

The majority of the patients (95.6%) were in the age group >40 years. A large group of the patients (57.1%) were present/reformed smokers. The major histological type was adenocarcinoma (60.9%), of which 22.8% patients were found to be epidermal growth factor receptor positive. Anaplastic lymphoma kinase rearrangement positivity rate was 4.8%. Furthermore, 68% patients had Stage 4 disease. Upfront palliative chemotherapy (CT) was offered in 61.8% patients and pemetrexed with platinum compounds was the main CT regimen (46.6%). Partial response was achieved in 45.7% patients, whereas stable disease was observed in 10.9% cases. Median progression-free survival was 5 months and overall survival was 55% at 36 months.

CONCLUSION

NSCLC forms the largest subgroup of lung cancer with the patients presenting with advanced stages of disease. This area needs to be explored for the early detection and subsequently the radical treatment of the patients. Personalized approach may be considered for the management of lung cancer by identifying new predictive and prognostic biomarkers of this disease.

Accuracy of intra-operative frozen section and its role in the diagnostic evaluation of ovarian tumors

Summary

OBJECTIVE

This retrospective study was undertaken to evaluate the accuracy and role of intra-operative frozen section in the diagnosis of ovarian tumors.

MATERIALS AND METHODS

Retrospective study of 804 ovarian frozen section results between June 2010 and June 2014 was examined to determine the accuracy of frozen section diagnosis. The intra-operative frozen section diagnosis was compared with the permanent (paraffin) section and the overall accuracy, sensitivity, specificity, and positive and negative predictive values of the frozen section were studied.

RESULTS

The overall accuracy to determine the status of malignancy was 92.6%. There were 38 (7.4%) false negative and no false positive frozen section diagnoses.The sensitivity, specificity, and positive predictive and negative predictive values for benign ovarian tumors were 100.0%, 97.0%, 91.3%, and 100.0%, respectively; for borderline tumors they were 64.3%, 97.0%, 91.5%, and 94.0%, respectively, and for malignant tumors they were 90.0%, 100.0%, 100.0%, and 85.5%, respectively.

CONCLUSION

This study concluded that frozen section appears to be an adequate technique for the histopathological diagnosis of ovarian tumors, with some limitations observed among borderline and mucinous tumors.

Clinical and epidemiological study of EGFR mutations and EML4-ALK fusion genes among Indian patients with adenocarcinoma of the lung

Background

Mutation in the tyrosine kinase domain of epidermal growth factor receptor (EGFR) is a common feature observed in lung adenocarcinoma. A fusion gene between echinoderm microtubule-associated protein-like 4 (EML4) and the intracellular domain of anaplastic lymphoma kinase (ALK), named EML4-ALK, has been identified in a subset of non-small-cell lung cancer (NSCLC) tumors. The objective of this study was to determine the prevalence of EGFR mutations and EML4-ALK fusions in Indian patients with NSCLC (adenocarcinoma) as well as evaluate their clinical characteristics.

Patients and methods

Patients with NSCLC, adenocarcinoma histology, whose tumors had been tested for EGFR mutational status, were considered for this study. ALK gene rearrangement was detected by fluorescence in situ hybridization using the Vysis ALK Break Apart Rearrangement Probe Kit. ALK mutation was tested in samples that were negative for EGFR mutation.

Results

A total of 500 NSCLC adenocarcinoma patients were enrolled across six centers. There were 337 (67.4%) men and 163 (32.6%) women with a median age of 58 years. One hundred and sixty-four (32.8%) blocks were positive for EGFR mutations, whereas 336 (67.2%) were EGFR wild-type. Of the 336 EGFR-negative blocks, EML4-ALK fusion gene was present in 15 (4.5%) patients, whereas 321 (95.5%) tumors were EML4-ALK negative. The overall incidence of EML4-ALK fusion gene was 3% (15/500).

Conclusion

The incidence of EGFR mutations (33%) in this Indian population is close to the reported incidence in Asian patients. EML4-ALK gene fusions are present in lung adenocarcinomas from Indian patients, and the 3% incidence of EML4-ALK gene fusion in EGFR mutation-negative cases is similar to what has been observed in other Western and Asian populations. The mutual exclusivity of EML4-ALK and EGFR mutations suggests implementation of biomarker testing for tumors harboring ALK rearrangements in order to identify patients that can benefit from newer targeted therapies.

Mapping and identification of a Cicer arietinum NSP2 gene involved in nodulation pathway

For the first time the putative NSP2 gene in chickpea has been identified using pairs of NILs differing for the Rn1 / rn1 nodulation gene that was located in LG5 of chickpea genetic map. An intraspecific cross between the mutant non-nodulating genotype PM233, carrying the recessive gene rn1, and the wild-type CA2139 was used to develop two pairs of near-isogenic lines (NILs) for nodulation in chickpea. These pairs of NILs were characterized using sequence tagged microsatellite site (STMS) markers distributed across different linkage groups (LGs) of the chickpea genetic map leading to the detection of polymorphic markers located in LG5. Using this information, together with the genome annotation in Medicago truncatula, a candidate gene (NSP2) known to be involved in nodulation pathway was selected for mapping in chickpea. The full length sequence obtained in chickpea wild-type (CaNSP2) was 1,503 bp. Linkage analysis in an F3 population of 118 plants derived from the cross between the pair of NILS NIL7-2A (nod) × NIL7-2B (non-nod) revealed a co-localization between CaNSP2 and Rn1 gene. These data implicate the CaNSP2 gene as a candidate for identity to Rn1, and suggest that it could act in the nodulation signaling transduction pathway similarly to that in other legumes species.

Functional changes of the cortical motor system in hereditary spastic paraparesis

BACKGROUND

Hereditary spastic paraparesis (HSP) is a heterogeneous group of disorders characterized by progressive bilateral lower limb spasticity. Functional imaging studies in patients with corticospinal tract involvement have shown reorganization of motor circuitry. Our study investigates functional changes in sensorimotor brain areas in patients with HSP.

METHODS

Twelve subjects with HSP and 12 healthy subjects were studied. Functional magnetic resonance imaging (fMRI) was used to measure brain activation during right-hand finger tapping. Image analysis was performed using general linear model and regions of interest (ROI)-based approach. Weighted laterality indices (wLI) and anterior/posterior indicies (wAI and wPI) were calculated for predefined ROIs.

RESULTS AND DISCUSSION

Comparing patients and controls at the same finger-tapping rate (1.8 Hz), there was increased fMRI activation in patients' bilateral posterior parietal cortex and left primary sensorimotor cortex. No differences were found when comparing patients and controls at 80% of their individual maximum tapping rates. wLI of the primary sensorimotor cortex was significantly lower in patients. Subjects with HSP also showed a relative increase in the activation of the posterior parietal and premotor areas compared with that of the primary sensorimotor cortex. Our findings demonstrate an altered pattern of cortical activation in subjects with HSP during motor task. The increased activation probably reflects reorganization of the cortical motor system.

Classification of chemicals according to mechanism of aquatic toxicity: an evaluation of the implementation of the Verhaar scheme in Toxtree

A number of mechanisms have been identified that can lead to (acute) aquatic toxicity. The assignment of compounds to a particular mechanism of action is important in the development and utilisation of (quantitative) structure-activity relationships ((Q)SARs) for ecotoxicity. Assignment to a mechanism can be difficult; however in 1992 Verhaar et al. published a series of structural rules which aimed to classify compounds according to mechanism of action. Recent interest has seen the Verhaar rules coded into freely available software such as Toxtree available from the European Chemicals Bureau. To date, a complete critical evaluation of these rules has been lacking. Therefore, the aim of this study was to evaluate the Toxtree implementation of the Verhaar rules using two well characterised aquatic toxicity datasets (Pimephales promelas and Tetrahymena pyriformis phenol databases) for which mechanisms of toxic action are well established. The present study highlights rule, and possible coding, errors that may lead to misclassifications. Improvements to both the rules and prediction architecture are suggested. In particular further rules to improve predictions for polar narcosis (class 2) are suggested.

Comparative studies on cellular gene regulation by HIV-1 based vectors: implications for quality control of vector production

Among the recent gene therapy protocols, vectors that can stably express transgenes, for example, HIV-1-based vectors, are particularly desirable. There have been no direct reports on insertional mutagenesis by lentiviral vectors; however, the severe pathogenic nature of their parental virus (HIV-1) is still a major safety concern surrounding these vectors and prevents the progress with their clinical application. We reason that by investigating the host response we shall be able to assess the safety and potential effects of the vectors on targeted cells and understand the interaction between vectors and the host. For this, two major sets of experiments were conducted. Initially, we used cDNA microarray methodology to examine cellular gene profile in human primary umbilical cord endothelial cells (HUVECs) after HIV-1-based VSV-G/GFP vector transduction and observed a modest effect of HIV-1-based vectors on HUVECs. The represented functional categories include transcription and translation factors, tumour antigens, complement factors and signal transduction factors. Some of the differentially expressed genes, for example, Clusterin, CD151, Ku antigen and eIF4gamma, could have oncogenic potential. In the second approach, we systematically compared five different viral vectors, that is, HIV-1-based VSV-G/Empty, VSV-G/GFP, VSV-G/puro, Amph/GFP and MLV-based Amph/Laz, for the effects of individual viral components on cellular gene regulation. Our comparative results demonstrated a regulatory function of Gag/Pol proteins on cellular gene expression. The significance of our findings in relation to the safety of HIV-1 vectors and the importance of quality control of vector production will be presented and discussed.

Prooxidant property of green tea polyphenols epicatechin and epigallocatechin-3-gallate: implications for anticancer properties

It is believed that anticancer and apoptosis inducing properties of green tea are mediated by it's polyphenolic constituents particularly catechins. A number of reports have shown that green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) is among the most effective chemopreventive and apoptosis-inducing agents present in the beverage. Plant polyphenols are naturally occurring antioxidants but they also exhibit prooxidant properties. Over the last several years we have shown that various classes of plant polyphenols including flavonoids, curcuminoids and tannins are capable of catalyzing oxidative DNA cleavage particularly in the presence of transition metal ions such as copper and iron. With a view to understand the chemical basis of various pharmacological properties of green tea, in this paper we have compared the prooxidant properties of green tea polyphenols--EGCG and EC ((-)-epicatechin). The rate of oxidative DNA degradation as well as hydroxyl radical and superoxide anion formation was found to be greater in the case of EGCG as compared with EC. It was also shown that copper mediated oxidation of EC and EGCG possibly leads to the formation of polymerized polyphenols. Further, it was indicated that copper oxidized catechins were more efficient prooxidants as compared with their unoxidized forms. These results correlate with the observation by others that EGCG is the most effective apoptosis inducing polyphenol present in green tea. They are also in support of our hypothesis that prooxidant action of plant polyphenols may be an important mechanism of their anticancer properties. A model for binding of Cu(II) to EC has been presented where the formation of quinone and a quinone methide has been proposed.

The biflavonoid, amentoflavone degrades DNA in the presence of copper ions

Previous reports from this laboratory have shown that flavonoids including apigenin are capable of inducing oxidative DNA cleavage in the presence of copper ions. In the present report, we have examined the ability of amentoflavone, a biflavonoid which is a dimer of apigenin, to catalyze the degradation of DNA. Amentoflavone was found to degrade calf thymus DNA in the presence of Cu(II) at a rate almost twice that of apigenin. Amentoflavone was also shown to reduce Cu(II) to Cu(I) and to generate hydroxyl radicals in the presence of copper ions. In the presence of Cu(II), the absorption spectrum of amentoflavone undergoes a shift and a quenching effect indicating that the biflavonoid is capable of binding to copper ions. Amentoflavone and apigenin were isolated from Cycas rumphii and Trifolium alexandrinum, respectively. The results are discussed in relation to the putative chemopreventive mechanism of amentoflavone.

Serotonin-Cu(II)-mediated DNA cleavage: mechanism of copper binding by serotonin

It has been proposed that considerable DNA damage may be caused by endogenous metabolites produced during the body's normal metabolic processes. 5-hydroxytryptamine (serotonin) is an important neurotransmitter in brain and spinal cord. We have previously shown that serotonin induces oxidative cleavage of DNA strands in the presence of copper ions. In the present paper we have examined the mechanism of copper binding by serotonin using absorption spectroscopy, Cu(II)-mediated lipid peroxidation and by determining the oxidation of the serotonin molecule. Addition of increasing concentrations of Cu(II) to serotonin leads to a progressive enhancement in the absorption band and is accompanied by a shift towards a lower wavelength indicative of the formation of an oxidised species of serotonin. Studies with the structurally related molecules tryptophan and melatonin showed that only serotonin is able to reduce Cu(II) to Cu(I). Similarly, only serotonin was found to be able to abolish the copper-mediated peroxidation of mitochondria. These results suggested the involvement of the phenolic group in copper binding. Further, it was also shown that the binding of copper to serotonin leads to the formation of a quinone in the absence of molecular oxygen. Based on these results, a model has been proposed in which serotonin reduces two molar equivalents of Cu(II) to Cu(I) through a reaction involving two electron oxidation of the phenolic ring to a quinone methide.

Brain ischemia and reperfusion activates the eukaryotic initiation factor 2alpha kinase, PERK

Reperfusion after global brain ischemia results initially in a widespread suppression of protein synthesis in neurons, which persists in vulnerable neurons, that is caused by the inhibition of translation initiation as a result of the phosphorylation of the alpha-subunit of eukaryotic initiation factor 2 (eIF2alpha). To identify kinases responsible for eIF2alpha phosphorylation [eIF2alpha(P)] during brain reperfusion, we induced ischemia by bilateral carotid artery occlusion followed by post-ischemic assessment of brain eIF2alpha(P) in mice with homozygous functional knockouts in the genes encoding the heme-regulated eIF2alpha kinase (HRI), or the amino acid-regulated eIF2alpha kinase (GCN2). A 10-fold increase in eIF2alpha(P) was observed in reperfused wild-type mice and in the HRI-/- or GCN2-/- mice. However, in all reperfused groups, the RNA-dependent protein kinase (PKR)-like endoplasmic reticulum eIF2alpha kinase (PERK) exhibited an isoform mobility shift on SDS-PAGE, consistent with the activation of the kinase. These data indicate that neither HRI nor GCN2 are required for the large increase in post-ischemic brain eIF2alpha(P), and in conjunction with our previous report that eIF2alpha(P) is produced in the brain of reperfused PKR-/- mice, provides evidence that PERK is the kinase responsible for eIF2alpha phosphorylation in the early post-ischemic brain.

Nitric-oxide-induced inhibition of glyceraldehyde-3-phosphate dehydrogenase may mediate reduced endothelial cell monolayer integrity in an in vitro model blood-brain barrier

The process of nitric-oxide (NO)-induced cellular toxicity may involve energy deprivation since the radical is reported to prevent both mitochondrial oxidative phosphorylation and glycolysis. In order to determine whether these processes are important in NO-induced blood-brain barrier (BBB) dysfunction, we used a cell culture model of the BBB and compared the effects of gaseous NO, potassium cyanide (KCN, a mitochondrial respiratory chain inhibitor) and iodoacetate [IA, an inhibitor of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH)] on endothelial cell ATP content, GAPDH activity and barrier integrity. NO lead to a rapid breakdown in model barrier integrity and resulted in a reduction in endothelial cell ATP content and GAPDH activity. KCN had no effect on endothelial cell ATP content or barrier integrity, while IA, at a concentration that completely blocked endothelial cell GAPDH activity, resulted in a rapid decline in ATP content but did not lead to a decline in barrier integrity until at least 2 h of exposure. These results indicate that inhibition of endothelial cell GAPDH activity rather than mitochondrial respiration causes an energy deficiency and delayed barrier dysfunction. However, the rapid detrimental effects of gaseous NO on barrier integrity cannot be fully explained by endothelial cell energy depletion and may be related to the actions of the free radical and its products on cellular lipids.

Tolerance to diacetyl morphine antinociception: effects on brain serotonin

The effects of 5 mg kg-1 diacetyl morphine (DAM) on brain serotonin metabolism of rats were investigated following tolerance to the antinociceptive effects of 2.5 mg kg-1 DAM. Brain levels of tryptophan and 5-hydroxy indoleacetic acid (5-HIAA) were higher in the DAM-tolerant rats killed 24 h after last daily administration of 2.5 mg kg-1 DAM. Administration of 5 mg kg-1 DAM produced less antinociception in DAM-tolerant than DAM-naive rats and increased brain tryptophan concentration in both tolerant and naive rats. 5-HIAA concentrations increased only in naive rats. Combined use of drugs interfering with brain 5-HT turnover along with opiates may be of future benefit for the treatment of chronic pain.

Equid herpesviruses 1 and 4 encode functional homologs of the herpes simplex virus type 1 virion transactivator protein, VP16

The herpes simplex virus type 1 (HSV-1) tegument protein VP16 is a potent transcriptional inducer of immediate-early gene expression, comprising an N-terminal domain involved in binding DNA linked to an acidic transactivating C-terminal domain. The gene encoding the counterpart of this protein in equid herpesvirus 4 (EHV-4) was sequenced. Comparisons with VP16 and the homologous proteins of equine herpesvirus 1 (EHV-1) and varicella-zoster virus (VZV) showed that a region in the N-terminal domain involved in formation of a complex with cellular proteins is partially conserved in all four proteins. In contrast, the C-terminal regions of the EHV proteins, like that of VZV, are not particularly acidic and are not significantly conserved with respect to the C-terminal region of VP16. Nevertheless, transient expression experiments indicated that the EHV-1 and EHV-4 proteins are able to transactivate HSV-1 and EHV-1 immediate-early promoters in a dose-dependent manner, which suggests that this activity is not dependent on an acidic C-terminal domain.