Electrophysiology and 3D-imaging reveal properties of human intracardiac neurons and increased excitability with atrial fibrillation.

Altered autonomic input to the heart plays a major role in atrial fibrillation (AF). Autonomic neurons termed ganglionated plexi (GP) are clustered on the heart surface to provide the last point of neural control of cardiac function. To date the properties of GP neurons in humans are unknown. Here we have addressed this knowledge gap in human GP neuron structure and physiology in patients with and without AF. Human right atrial GP neurons embedded in epicardial adipose tissue were excised during open heart surgery performed on both non-AF and AF patients and then characterised physiologically by whole cell patch clamp techniques. Structural analysis was also performed after fixation at both the single cell and at the entire GP levels via three-dimensional confocal imaging. Human GP neurons were found to exhibit unique properties and structural complexity with branched neurite outgrowth. Significant differences in excitability were revealed between AF and non-AF GP neurons as measured by lower current to induce action potential firing, a reduced occurrence of low action potential firing rates, decreased accommodation and increased synaptic density. Visualisation of entire GPs showed almost all neurons are cholinergic with a small proportion of noradrenergic and dual phenotype neurons. Phenotypic distribution differences occurred with AF including decreased cholinergic and dual phenotype neurons, and increased noradrenergic neurons. These data show both functional and structural differences occur between GP neurons from patients with and without AF, highlighting that cellular plasticity occurs in neural input to the heart that could alter autonomic influence on atrial function. KEY POINTS: The autonomic nervous system plays a critical role in regulating heart rhythm and the initiation of AF; however, the structural and functional properties of human autonomic neurons in the autonomic ganglionated plexi (GP) remain unknown. Here we perform the first whole cell patch clamp electrophysiological and large tissue confocal imaging analysis of these neurons from patients with and without AF. Our data show human GP neurons are functionally and structurally complex. Measurements of action potential kinetics show higher excitability in GP neurons from AF patients as measured by lower current to induce action potential firing, reduced low firing action potential rates, and decreased action potential accommodation. Confocal imaging shows increased synaptic density and noradrenergic phenotypes in patients with AF. Both functional and structural differences occur in GP neurons from patients with AF that could alter autonomic influence on atrial rhythm.

Studies on effects of Andrographis paniculata (Burm.f.) and Andrographis lineata nees (Family: Acanthaceae) extracts against two mosquitoes Culex quinquefasciatus (Say.) and Aedes aegypti (Linn.).

OBJECTIVE: To investigate the studies on effects of Andrographis paniculata (A. paniculata) (Burm.f.) and Andrographis lineata (A. lineata) nees (Family: Acanthaceae) extracts against two mosquitoes Culex quinquefasciatus (Cx. quinquefasciatus) (Say.) and Aedes aegypti (Ae. aegypti) (Linn.). METHODS: The aqueous and petroleum ether extracts of two plant species, A. paniculata and A. lineate were examined against the larvae of A. aegypti (L.) and Cx. quinquefasciatus with gradually increasing concentration ie. from 50 to 200 ppm of solvent extracts and to test their activity in combination with each other. RESULTS: In a 24 h bioassay experiment with plant extracts, highest mortalities were recorded at 200 ppm of concentrations for leaves of A. lineta and A. paniculata individually. For combination effect, only 150 ppm of the mixture of solvent extracts of petroleum ether: aqueous (1:1) extracts showed 100% mortality after 24 h of exposure. CONCLUSIONS: The results show that, insecticides of plant combination is ecofriend and has better larvicidal activity compared to individual extracts.

Phylogeny of Indian rhizophoraceae based on the molecular data from chloroplast tRNA(LEU)UAA intergenic sequences.

Molecular identification data of unexplored Indian Rhizophoraceae an eco-friendly mangroves are an imperative aspect in molecular phylogenetics. We describe the phylogenetic relationships among the Rhizophoraceae genus Rhizophora, Ceriops and Bruguiera using tRNA Leu (UAA) intron sequences as a molecular marker. The results of present study reveals congeneric relationship between R. apiculata, R. mucronata, B. gymnorhiza indicating a high degree of gene flow within them and the pairwise distribution of study plants among Rhizophoraceae family. The phylogram constructed using tRNA Leu sequence clearly clustered the species of the same genus in individual group. The stem-loop could be divided into two classes, both built up from two base pairing heptanucleotide repeats. Size variation was primarily caused by different numbers of repeats but some strains also contained additional sequences in this stem-loop. The statistical summaries of DNA sequence data can enable to identify the structural signature of the genome as well as to classify phylogenetic relationships among different species reflected in the difference of genetic diversity distributions within their DNA sequences.

Direct organogenesis of seaside heliotrope (Heliotropium crassavicum) using stem explants.

Heliotropium crassavicum L. is a sand binder salt marsh herb with enormous traditional value and widely found in South Asia America and Europe. In the direct method of regeneration from stem explants, we observed the maximum number of shoot regeneration after four weeks culture of MS elongation medium with 2.0 mg L(-1) of 2, 4-D (17.27 +/- 0.51). It was clear that MS medium with 2.0 mg mL(-1) 2, 4-D alone suitable for shoot multiplication as well as shoot elongation then compared to other combination of auxin and cytokinin. In vitro shoots were excised from shoot clumps and transferred to rooting medium containing 2, 4-dichlorophenoxy acetic acid (0.5-3.0 mg L(-1)). The maximum number of root regeneration (6.4 +/- 0.416) and root length (6.08 +/- 0.07) were observed in MS rooting medium fortified with 2.5 mg L(-1) of 2, 4-D after 2 weeks of culture. 85% of in vitro raised plantlets with well-developed shoots and roots were transferred to ex vivo conditions into polythene bag containing sterile compost with ratio (v/v/v) of organic fertilizer: sand: peat (1:2:2; 3:1:0 or 2:2:1). Sixty five percent of acclimated plants were transferred to the pots under full sun where they grew well without any detectable phenotypic variations.

Monitoring community mobilisation and organisational capacity among high-risk groups in a large-scale HIV prevention programme in India: selected findings using a Community Ownership and Preparedness Index.

BACKGROUND: In a participatory approach to health and development interventions, defining and measuring community mobilisation is important, but it is challenging to do this effectively, especially at scale. METHODS: A cross-sectional, participatory monitoring tool was administered in 2008-2009 and 2009-2010 across a representative sample of 25 community-based groups (CBGs) formed under the Avahan India AIDS Initiative, to assess their progress in mobilisation, and to inform efforts to strengthen the groups and make them sustainable. The survey used a weighted index to capture both qualitative and quantitative data in numeric form. The index permitted broad, as well as highly detailed, analysis of community mobilisation, relevant at the level of individual groups, as well as state-wide and across the whole programme. RESULTS: The survey demonstrated that leadership and programme management were the strongest areas among the CBGs, confirming the programme's investment in these areas. Discussion of the Round 1 results led to efforts to strengthen governance and democratic decision making in the groups, and progress was reflected in the Round 2 survey results. CBG engagement with state authorities to gain rights and entitlements and securing the long-term financial stability of groups remain a challenge. CONCLUSION: The survey has proven useful for informing the managers of programmes about what is happening on the ground, and it has opened spaces for discussion within community groups about the nature of leadership, decision making and their goals, which is leading to accelerated progress. The tool provided useful data to manage community mobilisation in Avahan.

Design of a Community Ownership and Preparedness Index: using data to inform the capacity development of community-based groups.

BACKGROUND: Community mobilisation is an important component of a participatory approach to health and development interventions. However, it is challenging to define, measure and assess community participation and ownership of a programme, especially at scale. METHODS: An iterative cross-sectional survey was designed for implementation across a representative sample of community-based groups, using a weighted index that captured both qualitative and quantitative data in a standardised form. These data were aggregated at the level of individual groups, as well as state-wide or across the whole programme. Community participation in the survey is a primary feature of the methodology and was integral to the process of designing the index and administering the survey. RESULTS: The survey provided programme management and communities with objective tools for monitoring community mobilisation across a large-scale and complex intervention covering 32 districts in India. The implementation of the survey engaged communities in an open discussion of their goals and capabilities and helped them to challenge the power dynamics between themselves and other stakeholders. CONCLUSIONS: It is possible to translate the theoretical premises of participatory development into a tool that both measures and fosters meaningful participation. The active participation of community members in the collection and analysis of data on their mobilisation suggests that monitoring of participation can be undertaken to inform a scaled-up programme and can be a useful intervention in its own right.

Antidiabetic effect of a black mangrove species Aegiceras corniculatum in alloxan-induced diabetic rats.

Earlier ethnopharmacological records divulged the traditional usages of mangrove Aegiceras corniculatum (Linn.) Blanco distributed in coastal and estuarine areas of Southeast India. Excluding scientific knowledge of A. corniculatum against diabetes an upgrowing endocrinal disorder, our present study evaluated the effect on alloxan-induced diabetic rats. Diabetes was induced in adult rats of the Wistar strain by intraperitoneal injection of alloxan monohydrate. The experimental rats were administered with leaf suspension of A. corniculatum post orally using an intragastric tube. On completion of the 60-day treatment, a range of biochemical parameters were tested including liver hexokinase, glucose-6phosphatase and fructose 1, 6 bisphosphatase in the liver of control and allaxon-diabetic rats. As a result, A. corniculatum leaf suspension showed moderate reduction in blood glucose (from 382 ± 34 to 105 ± 35), glycosylated hemoglobin, a decrease in the activities of glucose-6 phosphatase and fructose 1, 6-bisphosphatase, and an increase activity of liver hexokinase achieved through the oral administration of extract on 100 mg/kg. The present findings support promising results in terms of antidiabetic activities establishing its candidacy for further purification of individual compound in order to understand their mechanism of action.

Biomedical potential of silver nanoparticles synthesized from calli cells of Citrullus colocynthis (L.) Schrad.

BACKGROUND: An increasingly common application is the use of silver nanoparticles for antimicrobial coatings, wound dressings, and biomedical devices. In this present investigation, we report, biomedical potential of silver nanopaticles synthesized from calli extract of Citrullus colocynthis on Human epidermoid larynx carcinoma (HEp -2) cell line. METHODS: The callus extract react with silver nitrate solution confirmed silver nanoparticles synthesis through the steady change of greenish colour to reddish brown and characterized by using FT-IR, AFM. Toxicity on HEp 2 cell line assessed using MTT assay, caspase -3 assay, Lactate dehydrogenase leakage assay and DNA fragmentation assay. RESULTS: The synthesized silver nanoparticles were generally found to be spherical in shape with size 31 nm by AFM. The molar concentration of the silver nanoparticles solution in our present study is 1100 nM/10 mL. The results exhibit that silver nanoparticles mediate a dose-dependent toxicity for the cell tested, and the silver nanoparticles at 500 nM decreased the viability of HEp 2 cells to 50% of the initial level. LDH activities found to be significantly elevated after 48 h of exposure in the medium containing silver nanoparticles when compared to the control and Caspase 3 activation suggested that silver nanoparticles caused cell death through apoptosis, which was further supported by cellular DNA fragmentation, showed that the silver nanoparticles treated HEp2 cells exhibited extensive double strand breaks, thereby yielding a ladder appearance (Lane 2), while the DNA of control HEp2 cells supplemented with 10% serum exhibited minimum breakage (Lane 1). This study revealed completely would eliminate the use of expensive drug for cancer treatment.

Functionalized graphene sheets for polymer nanocomposites.

Polymer-based composites were heralded in the 1960s as a new paradigm for materials. By dispersing strong, highly stiff fibres in a polymer matrix, high-performance lightweight composites could be developed and tailored to individual applications. Today we stand at a similar threshold in the realm of polymer nanocomposites with the promise of strong, durable, multifunctional materials with low nanofiller content. However, the cost of nanoparticles, their availability and the challenges that remain to achieve good dispersion pose significant obstacles to these goals. Here, we report the creation of polymer nanocomposites with functionalized graphene sheets, which overcome these obstacles and provide superb polymer-particle interactions. An unprecedented shift in glass transition temperature of over 40 degrees C is obtained for poly(acrylonitrile) at 1 wt% functionalized graphene sheet, and with only 0.05 wt% functionalized graphene sheet in poly(methyl methacrylate) there is an improvement of nearly 30 degrees C. Modulus, ultimate strength and thermal stability follow a similar trend, with values for functionalized graphene sheet- poly(methyl methacrylate) rivaling those for single-walled carbon nanotube-poly(methyl methacrylate) composites.

Electrical Impedance Spectroscopy Study of Biological Tissues.

The objective of this study was to investigate the electrical impedance properties of rat lung and other tissues ex vivo using Electrical Impedance Spectroscopy. Rat lungs (both electroporated and naïve (untreated)), and mesenteric vessels (naïve) were harvested from male Sprague-Dawley rats; their electrical impedance were measured using a Solartron 1290 impedance analyzer. Mouse lung and heart samples (naïve) were also studied. The resistance (Real Z, ohm) and the reactance (Im Z, negative ohm)) magnitudes and hence the Cole-Cole (Real Z versus Im Z) plots are different for the electroporated lung and the naive lung. The results confirm the close relationship between the structure and the functional characteristic. These also vary for the different biological tissues studied. The impedance values were higher at low frequencies compared to those at high frequencies. This study is of practical interest for biological applications of electrical pulses, such as electroporation, whose efficacy depends on cell type and its electrical impedance characteristics.

POSSUM scoring for patients with fractured neck of femur.

BACKGROUND: POSSUM scoring is validated as an audit tool in general and orthopaedic surgery. It is also used for preoperative triage to assess perioperative risk. However its ability to predict mortality in specific surgical subgroups, such as patients with fractured neck of the femur, has not been studied. This study assessed the predictive capability of POSSUM for 30-day mortality after surgery for fractured neck of femur. METHODS: A cohort study was conducted in Queen's Medical Centre, Nottingham over a period of nearly 2 yr. Complete data from 1164 patients were analysed to compare the mortality predicted by POSSUM and the observed mortality. POSSUM risk of death was calculated using the original POSSUM equation, with modifications to the operative score appropriate for orthopaedic surgery. RESULTS: POSSUM predicted 181 (15.6%) deaths and the observed mortality was 119 (10.2%). The area under the receiver operating characteristic curve was 0.62, indicating poor performance by the POSSUM equation. CONCLUSION: POSSUM overpredicts mortality in hip fracture patients. It should be used with caution whether as an audit tool or for preoperative triage.

Perinatal inferior vena cava thrombosis and absence of the infrarenal inferior vena cava.

We report a case of infrarenal absence of the inferior vena cava (IVC) presenting as a major iliofemoral deep venous thrombosis in an adolescent. This is the first report of infrarenal IVC absence in which IVC thrombosis has been demonstrated in the perinatal period. We propose an association between perinatal IVC thrombosis and subsequent infrarenal IVC absence. In addition, the case demonstrates the importance of assessment for anatomical anomalies in patients presenting with apparently idiopathic deep venous thrombosis.

A survey of some Indian medicinal plants for anti-human immunodeficiency virus (HIV) activity.

BACKGROUND & OBJECTIVES: India has an extensive area of forest enriched with plant diversity. Several of these plants have been used as folklore medicines. However, the medicinal plants have rarely been investigated for anti-human immunodeficiency virus activity. Hence, some Indian medicinal plants were screened in vitro against human immunodeficiency virus (HIV). METHODS: The inhibitory effect of plant extracts on HIV replication was monitored in terms of inhibition of virus induced cytopathogenicity in MT-4 cells. The MT-4 cells were infected with HIV. The HIV infected or mock infected MT-4 cells were incubated at 37 degrees C in a CO2 incubator in the presence of the plant extracts. After five days, cell viability was measured by tetrazolium based colorimetric assay. RESULTS & INTERPRETATION: Of the 69 plant species screened, 16 were effective against HIV-1 and 4 were against both HIV-1 and HIV-2. The most effective extracts against HIV-1 and HIV-2 are respectively Cinnamomum cassia (bark) and Cardiospermum helicacabum (shoot + fruit). The findings provide a rationale for further studies on isolation of active principles and pharmacological evaluation.

Successful repair of a penetrating wound of the thoracic aorta.

Penetrating wounds of the aorta are not necessarily fatal. A successfully managed patient with a stab wound of the ascending aorta is reported, and some problems of management associated with such injuries are discussed.

Oesophagobronchial fistual presenting in the adult.

A case of congenital oesophagobronchial fistula presenting in adult life and treated successfully by surgical excision is reported. The most unusual feature is its late presentation and high origin.