Ultrastructural alterations of the tegument of Raillietina echinobothrida treated with the stem bark of Acacia oxyphylla (Leguminosae)

ETHNOPHARMACOLOGICAL RELEVANCE

The stem bark of Acacia oxyphylla Graham ex Bentham is used as an anthelmintic by the natives of Mizoram (North-East India).

AIM OF THE STUDY

The present study was performed to evaluate whether or not the plant-derived components caused any ultrastructural changes in the tegumental interface of the parasite.

MATERIALS AND METHODS

The test parasite Raillietina echinobothrida, the cestode of domestic fowl, was exposed to the ethanolic crude extract and acetone fraction of stem bark of Acacia oxyphylla for varying concentrations and time duration and processed for transmission electron microscopy as soon as paralysis set in the treated parasites.

RESULTS

Treatment with crude alcoholic extract and its acetone fraction revealed complete inactivation and flaccid paralysis of the cestode, which was soon followed by death. The treated parasites also exhibited intense vacuolization of the tegumental layers along with complete disorganization and/or erosion of microtriches.

CONCLUSIONS

Considerable structural alterations in the treated parasites are suggestive of an efficient vermicidal activity of the Acacia oxyphylla stem bark-derived botanicals against cestodes.

Splenic marginal zone antigen-presenting cells are critical for the primary allo-immune response to therapeutic factor VIII in hemophilia A

BACKGROUND

Alloimmune responses to intravenously administered protein therapeutics are the most common cause of failure of replacement therapy in patients with defective levels of endogenous proteins. Such a situation is encountered in some patients with hemophilia A, who develop inhibitory anti-factor (F)VIII alloantibodies after administration of FVIII to treat hemorrhages.

OBJECTIVES

The nature of the secondary lymphoid organs involved in the initiation of immune responses to human therapeutic has not been studied. We therefore investigated this in the case of FVIII, a self-derived exogenous protein therapeutic.

METHODS

The distribution of intravenously administered FVIII was followed after FVIII-deficient mice were injected with radiolabeled FVIII and using immunohistochemistry. The role of the spleen and antigen-presenting cells (APC) in the onset of the anti-FVIII immune response was analyzed upon splenectomy or treatment of the mice with APC-depleting compounds.

RESULTS

FVIII preferentially accumulated in the spleen at the level of metallophilic macrophages in the marginal zone (MZ). Surgical removal of the spleen or selective in vivo depletion of macrophages and CD11c-positive CD8 alpha-negative dendritic cells resulted in a drastic reduction in anti-FVIII immune responses.

CONCLUSIONS

Using FVIII-deficient mice as a model for patients with hemophilia A, and human pro-coagulant FVIII as a model for immunogenic self-derived protein therapeutics, our results highlight the importance of the spleen and MZ APCs in the initiation of immune responses to protein therapeutics. Identification of the receptors implicated in retention of protein therapeutics in the MZ may pave the way towards novel strategies aimed at reducing their immunogenicity.

Present status of understanding on the genetic etiology of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age with a prevalence of approximately 7-10% worldwide. PCOS reflects multiple potential aetiologies and variable clinical manifestations. This syndrome is characterized by serious health implications such as diabetes, coronary heart diseases and cancer and also leads to infertility. PCOS can be viewed as a heterogeneous androgen excess disorder with varying degrees of reproductive and metabolic abnormalities determined by the interaction of multiple genetic and environmental factors. In this paper, we have attempted a comprehensive review of primarily molecular genetic studies done so far on PCOS. We have also covered the studies focusing on the environmental factors and impact of ethnicity on the presentation of this syndrome. A large number of studies have been attempted to understand the aetiological mechanisms behind PCOS both at the clinical and molecular genetic levels. In the Indian context, majority of the PCOS studies have been confined to the clinical dimensions. However, a concrete genetic mechanism behind the manifestation of PCOS is yet to be ascertained. Understanding of this complex disorder requires comprehensive studies incorporating relatively larger homogenous samples for genetic analysis and taking into account the ethnicity and the environmental conditions of the population/cohort under study. Research focused on these aspects may provide better understanding on the genetic etiology and the interaction between genes and environment, which may help develop new treatment methods and possible prevention of the syndrome.

Interactions of bacterial polysaccharides with cationic dyes: physicochemical studies

Capsular polysaccharides (SPS) are an integral component of gram-negative bacteria, and also have potential use as vaccine. In this paper, interactions of SPS isolated from Klebsiella strains K20 and K51 with cationic dyes pinacyanol chloride (PCYN) and acridine orange (AO) were studied by absorbance and fluorescence measurements. Both the polysaccharides having glucuronic acid as the potential anionic site induced strong metachromasy (blue shift approximately 100 nm) in the PCYN. The spectral changes were studied at different polymer/dye molar ratios (P/D = 0-40). A complete reversal of metachromasy was observed upon addition of co-solvents, suggesting the breakaway of dye molecules from the biopolymer matrix. Binding constant, changes in free energy, enthalpy and entropy of the dye polymer complex were also computed from the spectral data at different temperatures to reveal the nature of the interaction. Quenching of fluorescence of AO by the polymers and the incorporated mechanisms were also explored.

Improving indoor air quality for poor families: a controlled experiment in Bangladesh

The World Health Organization's 2004 Global and Regional Burden of Disease Report estimates that acute respiratory infections from indoor air pollution (pollution from burning wood, animal dung, and other bio-fuels) kill a million children annually in developing countries, inflicting a particularly heavy toll on poor families in South Asia and Africa. This paper reports on an experiment that studied the use of different fuels in conjunction with different combinations of construction materials, space configurations, cooking locations, and household ventilation practices (use of doors and windows) as potentially-important determinants of indoor air pollution. Results from controlled experiments in Bangladesh were analyzed to test whether changes in these determinants can have significant effects on indoor air pollution. Analysis of the data shows, for example, that pollution from the cooking area is transported into living spaces rapidly and completely. Furthermore, it is important to factor in the interaction between outdoor and indoor air pollution. Hence, the optimal cooking location should take 'seasonality' in account. Among fuels, seasonal conditions seem to affect the relative severity of pollution from wood, dung, and other biomass fuels. However, there is no ambiguity about their collective impact. All are far dirtier than clean (LPG and Kerosene) fuels. The analysis concludes that if cooking with clean fuels is not possible, then building the kitchen with permeable construction material and providing proper ventilation in cooking areas will yield a better indoor health environment.

PRACTICAL IMPLICATIONS

Several village-level measures could significantly reduce IAP exposure in Bangladesh. All would require arrangements and the assert of male heads-of-household: negotiated bulk purchases of higher cost, cleaner fuels; purchase of more fuel-efficient stoves; peripheral location of cooking facilities; building the kitchen with permeable construction material; rotation of women in cooking roles, to reduce their exposure; and ventilation of smoke through a stack tall enough to disperse smoke over a relatively broad area. It is expected that village men and women will agree to these measures if they become convinced that IAP poses a serious risk to health, and their actions will significantly reduce the risk. The keys to success are effective public education about the sources and risks of IAP, and financial and technical assistance for changes in cooking arrangements.

Precipitation of cetyl (hexadecyl) pyridineum chloride using mono and divalent oxyanions

Experimental investigations have been carried out to observe the performance of precipitation behavior of potassium permanganate (KMnO4) and potassium dichromate (K2Cr2O7) in cetyl (hexadecyl) pyridineum chloride (CPC) solution. As in the case of Al3+-dodecylbenzenesulfonate systems [P. Somasundaran, K.P. Anathapadmanabhan, M.S. Celik, Langmuir 4 (1988) 1061-1063], the precipitation is found to be caused by interaction of CPC micelles with oxyanions. The counter oxyanions have a strong tendency to bind themselves to the surface of cationic CPC micelles. This lowered the free oxyanion concentration in solution. Therefore, to start precipitation, higher oxyanion concentration is required for higher CPC concentration. The effects of temperature, concentrations of both counter ions and CPC on the precipitation have been studied in detail. It has been observed that at CPC to KMnO4 concentration ratio of 1.0 (concentration of CPC and KMnO4 is 400ppm), the percentage precipitation of CPC is around 99.3 at 30 degrees C. The percent precipitation of CPC decreases to about 94% when temperature increases to 70 degrees C at the same condition. The extent of CPC precipitation increases at the same experimental condition when K2Cr2O7 is used instead of KMnO4.

A nanoparticulate indium tin oxide field-effect transistor with solid electrolyte gating

Reversible tuning of the transport properties of metallic conducting systems is not reported widely in the literature. Here, we report a junction field-effect transistor (FET) based on a transparent conducting oxide (TCO) nanoparticle channel and a solid polymer electrolyte as a gate. The device principle is based on the variation of the drain current induced by the capacitive double layer charging at the electrolyte/nanoparticle interfaces. A device with a metallic conducting channel made of indium tin oxide (ITO) nanoparticles exhibits an on/off ratio of 2 × 10(3) even when the gate potential is limited within the electrochemical capacitive region to avoid redox reactions at the interface. An FET device with metal-like conductance is always favored for the low dimensions of the device and a high on-state current. The field-effect mobility is calculated to be 24.3 cm(2) V(-1) s(-1). A subthreshold swing between 230 and 425 mV dec(-1) is observed.

Evaluation of water productivity and fish yield in sewage-fed vis-à-vis fertilized based carp culture

Reuse of wastewater in aquaculture provides a scope to enhance water productivity of the system. Quantification of nutrient inputs incorporated through treated domestic sewage with varying dosages viz. 79.3 x 10(5)lha(-1) and 67.7 x 10(5)lha(-1) and water productivity in a controlled carp culture system were assessed in comparison to those involved in a fertilized based one, with a view to correlate among physical, chemical and biological processes involved in fish yield under the systems. The net water productivities were measured on the basis of net return values (in Indian rupees; INR) from the carp production systems at a stocking density @ 5000 per ha with four species combination. Selected relevant water parameters such as dissolved oxygen, total alkalinity, biochemical oxygen demand (BOD5) in sewage effluent and fertilizer based systems were monitored along with certain biological parameters viz. gross primary productivity, fish production and water productivity. The nutrient inputs in terms of total ammonia-nitrogen (TAN) in effluents, total nitrogen (TN) in fertilizers and phosphorus (P2O5) in both effluents and fertilizers were found significantly correlated with biological production. The results of the experiment revealed that the sewage incorporation at 79.3 x 10(5)lha(-1) yielded similar gross fish production as recorded from fertilizer based system, whereas net water productivity using sewage as nutrient source was found 64% higher than that of a fertilizer based system.

Influence of culture media and environmental factors on mycelial growth and sporulation of Lasiodiplodia theobromae (Pat.) Griffon and Maubl

Lasiodiplodia theobromae, a common tea (Camellia sinensis) pathogen, usually does not sporulate or sporulates poorly in common media, which makes spore production difficult. In this study the effects of culture media, carbon source, nitrogen source, temperature, pH and light on mycelial growth and sporulation were evaluated. Among several carbon sources tested, glucose and sucrose were found superior for growth. Potassium nitrate supplemented media showed maximum growth amongst the tested inorganic nitrogen sources while peptone produced maximum growth among the tested organic nitrogen sources. Tea root extract supplemented potato dextrose agar medium was found to be the most suitable for mycelial growth and sporulation of L. theobromae. The fungus grow at temperatures ranging from 40 to 36 degrees C, with optimum growth at 28 degrees C and no growth was noted at 40 degrees C. There was no significant effect of different light period on growth of L. theobromae, but light enhanced sporulation. The fungus grow at pH 3.0-8.0 and optimum growth was observed at pH 6.0. Tea root extract supplemented potato dextrose agar medium with pH 6.0 was the most suitable for production of conidia of L. theobromae at 28 degrees C. Hence this media may be recommended for inoculum production for further studies.

Factor VIII inhibitors: role of von Willebrand factor on the uptake of factor VIII by dendritic cells

In patients with haemophilia A, factor VIII (FVIII) therapy leads to the development of anti-FVIII alloantibodies that inhibit FVIII pro-coagulant activity, in up to 25% of the cases. At a time when efficient viral screening procedures are at place, development of inhibitors poses the greatest threat to haemophilia A patients. Various risk factors, both patient and product-related, are responsible for the development of inhibitory antibodies. The role of FVIII-specific CD4+ T lymphocytes in the initiation of the humoral immune response to exogenous FVIII has been well. In view of their capacity to stimulate naïve T cells, dendritic cells (DCs) play a central role in the initiation of the primary immune response. Thus, in the context of a primary alloimmunization against FVIII, i.e. when FVIII-specific B lymphocytes are not there to take up FVIII from the circulation and to serve as antigen presenting cells (APCs), DCs are the only cell type that internalize FVIII, leading to activation of FVIII-specific CD4+ T lymphocytes. von Willebrand factor (VWF) present in plasma-derived FVIII therapeutic concentrates, is known to act as a chaperone molecule for procoagulant FVIII. In addition to its role in reducing the 'antigenicity' of FVIII, the role of VWF in the reduction of the 'immunogenicity' of therapeutic FVIII in patients with haemophilia A has also been suggested. We have recently demonstrated that VWF protects FVIII from being endocytosed by human DCs and subsequently being presented to FVIII-specific T cells. We propose that VWF may reduce the immunogenicity of FVIII by preventing, upstream from the activation of immune effectors, the entry of FVIII in professional antigen presenting cells.

Maternal alcohol consumption increases sphingosine levels in the brains of progeny mice

The effect of 'binge' alcohol upon sphingolipid metabolism in the fetal alcohol syndrome (FAS) was examined in pregnant mice (C57BL/6J) by administering a single dose of alcohol during the third trimester (gestational day 15-16). The control mice were administered a sucrose solution of equal caloric value. Brains from progeny at postnatal days 5, 15, 21 and 30 were dissected into three regions, and sphingolipid concentrations of the brain regions were determined including assay of monoglycosylceramide, ceramide, sphingosine and sphingomyelin. We found that a single dose of ethanol induces an elevation of sphingosine (2-3.5-fold) in the brain of progeny. The level of brain ceramide at a dose of 1.5 g/kg was significantly higher than control. Alcohol consumption during pregnancy induces neuronal loss in progeny brains. Our result suggests that the elevation of sphingosine in progeny brain induced by maternal alcohol consumption may be responsible for observed neuronal loss in FAS.

Inactivation of enzyme laccase and role of cosubstrate oxygen in enzymatic removal of phenol from water

Research was conducted to evaluate the potential use of laccase and its susceptibility to inactivation in an alternative enzyme-based treatment technology to remove parent phenol from buffered distilled water. Enzymatic oxidative polymerization of phenol with laccase was carried out in continuously stirred batch reactors. The reaction products were insoluble polymers, which precipitated out of the solution once their solubility limits were exceeded. The findings demonstrated that the polymeric products had significant effects on enzyme activity consumption and subsequent phenol removal. Enzyme species present in the reaction vessel were classified into enzyme remaining in the solution (type 1) and enzyme adhering to the precipitate polymers (type 2). Type 1 enzyme was more efficient in removal of phenol from solution compared with type 2. Subsequent filtration enhanced the phenol removal by removing type 2 enzyme adhering to the polymer particles and decelerating enzyme inactivation. The study also investigated the effects of available dissolved oxygen, provided through aeration and hydrogen peroxide addition, on phenol removal. Aeration and hydrogen peroxide addition increased the dissolved oxygen concentration, but had no effect on the progress curve for phenol removal.