Identification of optimal flow rate for culture media, cell density, and oxygen toward maximization of virus production in a fed-batch baculovirus-insect cell system

In recent times, it has been realized that novel vaccines are required to combat emerging disease outbreaks, and faster optimization is required to respond to global vaccine demands. Although, fed-batch operations offer better productivity, experiment-based optimization of a new fed-batch process remains expensive and time-consuming. In this context, we propose a novel computational framework that can be used for process optimization and control of a fed-batch baculovirus-insect cell system. Since the baculovirus expression vector system (BEVS) is known to be widely used platforms for recombinant protein/vaccine production, we chose this system to demonstrate the identification of optimal profile. Toward this, first, we constructed a mathematical model that captures the time course of cell and virus growth in a baculovirus-insect cell system. Second, the proposed model was used for numerical analysis to determine the optimal operating profiles of control variables such as culture media, cell density, and oxygen based on a multiobjective optimal control formulation. Third, a detailed comparison between batch and fed-batch culture was perfromed along with a comparison between various alternatives of fed-batch operation. Finally, we demonstrate that a model-based quantification of controlled feed addition in fed-batch culture is capable of providing better productivity as compared to a batch culture. The proposed framework can be utilized for the estimation of optimal operating regions of different control variables to achieve maximum infected cell density and virus yield while minimizing the substrate/media, uninfected cell, and oxygen consumption.

A computational model to uncover the biophysical underpinnings of neural firing heterogeneity in dissociated hippocampal cultures

Calcium (Ca2+ ) imaging reveals a variety of correlated firing in cultures of dissociated hippocampal neurons, pinpointing the non-synaptic paracrine release of glutamate as a possible mediator for such firing patterns, although the biophysical underpinnings remain unknown. An intriguing possibility is that extracellular glutamate could bind metabotropic receptors linked with inositol trisphosphate (IP3 ) mediated release of Ca2+ from the endoplasmic reticulum of individual neurons, thereby modulating neural activity in combination with sarco/endoplasmic reticulum Ca2+ transport ATPase (SERCA) and voltage-gated Ca2+ channels (VGCC). However, the possibility that such release may occur in different neuronal compartments and can be inherently stochastic poses challenges in the characterization of such interplay between various Ca2+ channels. Here we deploy biophysical modeling in association with Monte Carlo parameter sampling to characterize such interplay and successfully predict experimentally observed Ca2+ patterns. The results show that the neurotransmitter level at the plasma membrane is the extrinsic source of heterogeneity in somatic Ca2+ transients. Our analysis, in particular, identifies the origin of such heterogeneity to an intrinsic differentiation of hippocampal neurons in terms of multiple cellular properties pertaining to intracellular Ca2+ signaling, such as VGCC, IP3 receptor, and SERCA expression. In the future, the biophysical model and parameter estimation approach used in this study can be upgraded to predict the response of a system of interconnected neurons.

Computational framework to understand the clinical stages of COVID-19 and visualization of time course for various treatment strategies

Coronavirus disease 2019 is known to be regulated by multiple factors such as delayed immune response, impaired T cell activation, and elevated levels of proinflammatory cytokines. Clinical management of the disease remains challenging due to interplay of various factors as drug candidates may elicit different responses depending on the staging of the disease. In this context, we propose a computational framework which provides insights into the interaction between viral infection and immune response in lung epithelial cells, with an aim of predicting optimal treatment strategies based on infection severity. First, we formulate the model for visualizing the nonlinear dynamics during the disease progression considering the role of T cells, macrophages and proinflammatory cytokines. Here, we show that the model is capable of emulating the dynamic and static data trends of viral load, T cell, macrophage levels, interleukin (IL)-6 and TNF-α levels. Second, we demonstrate the ability of the framework to capture the dynamics corresponding to mild, moderate, severe, and critical condition. Our result shows that, at late phase (>15 days), severity of disease is directly proportional to pro-inflammatory cytokine IL6 and tumor necrosis factor (TNF)-α levels and inversely proportional to the number of T cells. Finally, the simulation framework was used to assess the effect of drug administration time as well as efficacy of single or multiple drugs on patients. The major contribution of the proposed framework is to utilize the infection progression model for clinical management and administration of drugs inhibiting virus replication and cytokine levels as well as immunosuppressant drugs at various stages of the disease.

Analytics Pipeline for Visualization of Single Cell RNA Sequencing Data from Brochoaveolar Fluid in COVID-19 Patients: Assessment of Neuro Fuzzy-C-Means and HDBSCAN

Since the mutation in SARS-COV2 poses new challenges in designing vaccines, it is imperative to develop advanced tools for visualizing the genetic information. Specially, it remains challenging to address the patient-to-patient variability and identify the signature for severe/critical conditions. In this endeavor we analyze the large-scale RNA-sequencing data collected from broncho-alveolar fluid. In this work, we have used PCA and tSNE for the dimension-reduction. The novelty of the current work is to depict a detailed comparison of k-means, HDBSAN and neuro-fuzzy method in visualization of high-dimension data on gene expression. Clinical Relevance- The subpopulation profiling can be used to study the patient-to patient variability when infected by SARS-COV-2 and its variants. The distribution of cell types can be relevant in designing new drugs that are targeted to control the distribution of epithelial cells T cells and macrophages.

Mathematical modeling of viral infection dynamics and immune response in SARS-CoV-2: A computational framework for testing drug efficacy

SARS-CoV-2 has emerged to cause the outbreak of COVID-19, which has expanded into a worldwide human pandemic. Although detailed experimental data on animal experiments would provide insight into drug efficacy, the scientists involved in these experiments would be exposed to severe risks. In this context, we propose a computational framework for studying infection dynamics that can be used to capture the growth rate of viral replication and lung epithelial cell in presence of SARS-CoV-2. Specifically, we formulate the model consisting of a system of non-linear ODEs that can be used for visualizing the infection dynamics in a cell population considering the role of T cells and Macrophages. The major contribution of the proposed simulation method is to utilize the infection progression model in testing the efficacy of the drugs having various mechanisms and analyzing the effect of time of drug administration on virus clearance.Clinical Relevance-The proposed computational framework incorporates viral infection dynamics and role of immune response in Covid-19 that can be used to test the impact of drug efficacy and time of drug administration on infection mitigation.

1041 A Systematic Review of the Reporting Quality of Surgical Randomised Controlled Trials in Head and Neck Cancer using the CONSORT Statement

Introduction

Randomised controlled trials (RCTs) are considered the gold standard for evaluating the efficacy of an intervention. However, previous research has shown that surgical specialities poorly report RCTs, making it difficult to ascertain if various biases have been appropriately minimised. This systematic review assesses the reporting quality of surgical head and neck cancer RCTs.

Method

A literature search of PubMed and Embase was performed. Papers were included if they reported RCTs which assessed a surgical technique used to treat or diagnose head and neck cancer published during or after 2011. Therefore, the CONSORT 2010 checklist was used to evaluate the reporting quality of these trials.

Results

41 papers were included. The mean CONSORT score was 16.5/25 (66% adherence) and the scores ranged from 7.5 (30%) to 25. The most common omissions were full trial protocol (found in 14.6%), participant recruitment method (22%) and effect size with precision estimate for all outcome measures (29.3%). The full design and implementation of the randomisation method was reported in 6 (14.6%). Papers published in journals which endorsed CONSORT had significantly higher scores (p = 0.02) and journal impact factor was significantly correlated with CONSORT score (p = 0.01).

Conclusions

We have identified several pieces of information that are underreported in surgical head and neck cancer RCTs. These omissions make understanding and comparing the methodologies and conclusions of RCTs more difficult. The endorsement of CONSORT by journals improved adherence, suggesting that wider adoption of the checklist may improve reporting.

Dissociation of the G protein βγ from the Gq-PLCβ complex partially attenuates PIP2 hydrolysis

Phospholipase C β (PLCβ), which is activated by the Gq family of heterotrimeric G proteins, hydrolyzes the inner membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP2), generating diacylglycerol and inositol 1,4,5-triphosphate (IP3). Because Gq and PLCβ regulate many crucial cellular processes and have been identified as major disease drivers, activation and termination of PLCβ signaling by the Gαq subunit have been extensively studied. Gq-coupled receptor activation induces intense and transient PIP2 hydrolysis, which subsequently recovers to a low-intensity steady-state equilibrium. However, the molecular underpinnings of this equilibrium remain unclear. Here, we explored the influence of signaling crosstalk between Gq and Gi/o pathways on PIP2 metabolism in living cells using single-cell and optogenetic approaches to spatially and temporally constrain signaling. Our data suggest that the Gβγ complex is a component of the highly efficient lipase Gαq_GTP-PLCβ-Gβγ. We found that over time, Gβγ dissociates from this lipase complex, leaving the less-efficient Gαq_GTP-PLCβ lipase complex and allowing the significant partial recovery of PIP2 levels. Our findings also indicate that the subtype of the Gγ subunit in Gβγ fine-tunes the lipase activity of Gq-PLCβ, in which cells expressing Gγ with higher plasma membrane interaction show lower PIP2 recovery. Given that Gγ shows cell- and tissue-specific subtype expression, our findings suggest the existence of tissue-specific distinct Gq-PLCβ signaling paradigms. Furthermore, these results also outline a molecular process that likely safeguards cells from excessive Gq signaling.

Mito-SinCe2 Approach to Analyze Mitochondrial Structure-Function Relationship in Single Cells

The cross talk between mitochondrial dynamic structure, determined primarily by mitochondrial fission and fusion events, and mitochondrial function of energetics, primarily ATP and ROS production, is widely appreciated. Understanding the mechanistic details of such cross talk between mitochondrial structure and function needs integrated quantitative analyses between mitochondrial dynamics and energetics. Here we describe our recently designed approach of mito-SinCe² that involves high resolution confocal microscopy of genetically expressed ratiometric fluorescent probes targeted to mitochondria, and its quantitative analyses. Mito-SinCe² analyses allows for quantitative analyses of mitochondrial structure-function relationship in single cells toward understanding the role of mitochondria and their heterogeneity in various physiological and pathological conditions.

Interplay of mitochondrial fission-fusion with cell cycle regulation: Possible impacts on stem cell and organismal aging

Declining mitochondrial function and homeostasis is a hallmark of aging. It is appreciated that the role of mitochondria is much more complex than generating reactive oxygen species to cause aging-related tissue damage. More recent literature describes that the ability of mitochondria to undergo fission or fusion events with each other impacts aging processes. A dynamic balance of mitochondrial fission and fusion events is required to sustain critical cellular functions including cell cycle. Specifically, cell cycle regulators modulate molecular activities of the mitochondrial fission (and fusion) machinery towards regulating cell cycle progression. In this review, we discus literature leading to our understanding on how shifts in the dynamic balance of mitochondrial fission and fusion can modulate progression through, exit from, and re-entry to the cell cycle or in undergoing senescence. Importantly, core regulators of mitochondrial fission or fusion are emerging as crucial stem cell regulators. We discuss the implication of such regulation in stem cells in the context of aging, given that aberrations in adult stem cells promote aging. We also propose a few hypotheses that may provide direction for further understanding about the roles of mitochondrial fission-fusion dynamics in aging biology.

Confocal Imaging and k-Means Clustering of GABAB and mGluR Mediated Modulation of Ca2+ Spiking in Hippocampal Neurons

Imaging cytosolic calcium in neurons is emerging as a new tool in neurological disease diagnosis, drug screening, and toxicity testing. Ca²⁺ oscillation signatures show a significant variation depending on GPCR targeting agonists. Quantification of Ca²⁺ spike trains in ligand induced Ca²⁺ oscillations remains challenging due to their inherent heterogeneity in primary culture. Moreover, there is no framework available for identification of optimal number of clusters and distance metric to cluster Ca²⁺ spike trains. Using quantitative confocal imaging and clustering analysis, we show the characterization of Ca²⁺ spiking in GPCR targeting drug-treated primary culture of hippocampal neurons. A systematic framework for selection of the clustering method instead of an intuition-based method was used to optimize the cluster number and distance metric. The results discern neurons with diverse Ca²⁺ response patterns, including higher amplitude fast spiking and lower spiking responses, and their relative percentage in a neuron population in absence and presence of GPCR-targeted drugs. The proposed framework was employed to show that the  clustering pattern of Ca²⁺ spiking can be controlled using GABA_B and mGluR targeting drugs. This approach can be used for unbiased measurement of neural activity and identification of spiking population with varying amplitude and frequencies, providing a platform for high-content drug screening.

Smart Data Analytics approach to model Complex Biochemical Oscillations in Hippocampal Neurons

Calcium spiking can be used for drug screening studies in pharmaceutical industries. However, performing experiments for multiple drugs and doses are highly expensive. The oscillatory behavior of calcium spiking data demonstrates extreme nonlinearity and phase singularity. This makes it more challenging to construct physics-based models for the experimental observations. In this scenario, data based modelling, such as Artificial Neural Networks (ANN), and thereafter the model based prediction of calcium profiles may offer a cost-effective and time saving solution. Therefore, a novel ANN building algorithm is presented in the current work, where data based simultaneous estimation of ANN architecture and nonlinear activation function stands out as the main highlight. The resultant ANN was then used to learn the oscillatory behavior in calcium ion concentration data, obtained from hippocampal neurons of rats by fluorescent labelling and confocal imaging. The paper shows that the novel technique can be used in general for emulating biochemical oscillations (with or without drug injection) and can be implemented to predict the cell-drug responses for intermediated doses. The proposed algorithm can also be used for obtaining high resolution data from low resolution experimental measurements.

Confocal imaging of cytosolic Ca2+ and fuzzy clustering reveal the circuit topology details underlying synchronization in hippocampal neurons

Neuronal synchronization contributes to various cognitive functions and disruption in synchronicity may lead to various diseased conditions. However, measurement of synchronicity at a higher spatial resolution remains challenging. Specifically, investigation on understanding the role of network topology in tuning the network activity and synchronicity remains sparse. In this context, we propose imaging of intracellular Ca²⁺ in primary cultures of hippocampal neurons using Fluo-4 as the fluorescent indicator using the confocal microscope. In order to identify the synchronous response from a set of heterogeneous Ca²⁺ spiking, we present fuzzy clustering of the oscillatory responses. Further, the synchronicity was measured through evaluation of the correlation between Ca²⁺ spiking trends. Confocal imaging and analysis show that neuronal connectivity and topology play an essential role in tuning the synchronicity of the neuronal network.

Finite element modeling, validation, and parametric investigations of a retinal reattachment stent

A new retinal reattachment surgical procedure is based on a stent that is deployed to press the retina back in place. An eye-stent finite element model studied the strain induced by the stent on retina. Finite element model simulations were performed for several stent geometric configurations (number of loops, wire diameter, and intraocular pressure). The finite element model was validated against experiment. Parametric studies demonstrated that stents could be successfully designed so that the maximum strain would be below permanent damage strain threshold of 2%.

Comparison of Calcium Dynamics and Specific Features for G Protein-Coupled Receptor-Targeting Drugs Using Live Cell Imaging and Automated Analysis

G protein-coupled receptors (GPCRs) are targets for designing a large fraction of the drugs in the pharmaceutical industry. For GPCR-targeting drug screening using cell-based assays, measurement of cytosolic calcium has been widely used to obtain dose-response profiles. However, it remains challenging to obtain drug-specific features due to cell-to-cell heterogeneity in drug-cell responses obtained from live cell imaging. Here, we present a framework combining live cell imaging of a cell population and a feature extraction method for classification of responses of drugs targeting GPCRs CXCR4 and α2AR. We measured the calcium dynamics using confocal microscopy and compared the responses for SDF-1α and norepinephrine. The results clearly show that the clustering patterns of responses for the two GPCRs are significantly different. Additionally, we show that different drugs targeting the same GPCR induce different calcium response signatures. We also implemented principal component analysis and k means for feature extraction and used nondominated (ND) sorting for ranking a group of drugs at various doses. The presented approach can be used to model a cell population as a mixture of subpopulations. It also offers specific advantages, such as higher spatial resolution, classification of responses, and ranking of drugs, potentially providing a platform for high-content drug screening.

α-Solanine induces ROS-mediated autophagy through activation of endoplasmic reticulum stress and inhibition of Akt/mTOR pathway

α-Solanine is a glycoalkaloid found in species of the nightshade family including potato. It was primarily reported to have toxic effects in humans. However, there is a growing body of literature demonstrating in vitro and in vivo anticancer activity of α-solanine. Most of these studies have shown activation of apoptosis as the underlying mechanism in antitumor activity of α-solanine. In this study, we report α-solanine as a potential inducer of autophagy, which may act synergistically or in parallel with apoptosis to exert its cytotoxic effect. Induction of autophagy was demonstrated by several assays including electron microscopy, immunoblotting of autophagy markers and immunofluorescence for LC3 (microtubule-associated protein 1 (MAP1) light chain-3) puncta. α-Solanine-induced autophagic flux was demonstrated by additionally enhanced – turnover of LC3-II and – accumulation of LC3-specific puncta after co-incubation of cells with either of the autophagolysosome inhibitors – chloroquine and – bafilomycin A1. We also demonstrated α-solanine-induced oxidative damage in regulating autophagy where pre-incubation of cells with reactive oxygen species (ROS) scavenger resulted in suppression of CM-H₂DCFDA (5 (and 6)-chloromethyl-2′,7′-dichlorodihydrofluorescein diacetate acetyl ester) fluorescence as well as decrease in LC3-II turnover. α-Solanine treatment caused an increase in the expression of endoplasmic reticulum (ER) stress proteins (BiP, activating transcription factor 6 (ATF6), X-box-binding protein 1, PERK, inositol-requiring transmembrane kinase/endonuclease 1, ATF4 and CCAAT-enhancer-binding protein (C/EBP)-homologous protein) suggesting activation of unfolded protein response pathway. Moreover, we found downregulation of phosphorylated Akt (Thr³⁰⁸ and Ser⁴⁷³), mammalian target of rapamycin (mTOR; Ser²⁴⁴⁸ and Ser²⁴⁸¹) and 4E-BP1 (Thr^37/46) by α-solanine implying suppression of the Akt/mTOR pathway. Collectively, our results signify that α-solanine induces autophagy to exert anti-proliferative activity by triggering ER stress and inhibiting Akt/mTOR signaling pathway.

Short-Pulse Laser-Based System for Detection of Tumors: Administration of Gold Nanoparticles Enhances Contrast

The objective of this paper is to demonstrate the use of gold nanoparticles, which accumulate in tumors due to the leakiness of tumor vasculature, as contrast agents for enhanced imaging in a time-resolved optical tomography system using short-pulse lasers for skin cancer detection in mouse model. It is found that intravenously administrated spherical gold nanoparticles broadened the temporal profile of reflected optical signals and enhanced the contrast between surrounding normal tissue and tumors. These results show that gold nanoparticles tuned to the wavelength of the laser can enhance the resolution and precision of laser-based cancer detection system.

Mucoadhesive nanoparticles for prolonged ocular delivery of natamycin: In vitro and pharmacokinetics studies

The aim of this study was to prepare natamycin encapsulated lecithin/chitosan mucoadhesive nanoparticles (NPs) for prolonged ocular application. These NPs were characterized by their mean particle size 213nm, encapsulation efficiency 73.57%, with a theoretical drug loading 5.09% and zeta potential +43. In vitro release exhibited a biphasic drug release profile with initial burst followed by a very slow drug release. The MIC(90) and zone of inhibition of NPs showed similar antifungal activity as compared to marketed suspension and free natamycin against Candida albicans and Aspergillus fumigates. The ocular pharmacokinetics of NPs and marketed formulation were evaluated in NZ rabbits. The NPs exhibit significant mucin adhesion. The AUC((0-∞)) was increased up to 1.47 fold and clearance was decreased up to 7.4-fold as compared to marketed suspension. The PK-PD and pharmacokinetic simulation was carried out to estimate optimum dosing regimen for good efficacy. Thus, lecithin/chitosan NPs could be considered useful approach aiming to prolong ocular residence and reduce dosing frequency.

Protective potential of Bacopa monniera (Brahmi) extract on aluminum induced cerebellar toxicity and associated neuromuscular status in aged rats

The present study attempts to assess the comparative effects of Bacopa monniera, (40 mg/kg body weight) and donepezil (2.5 mg/kg b. wt) on aluminum (100 mg / kg b. wt. of AlCl3) mediated oxidative damage in the cerebellum of aged rats (24 months) along with the associated dysfunctioning of neuromuscular coordination and motor activity. A significant decrease in the activities of antioxidant enzymes and increased total reacting oxygen species, lipid and protein peroxidation products observed in aluminum exposed rats. We observed that treatment with B. monniera extract restored the altered antioxidant enzyme activities more, when compared with donepezil. However, acetylcholinesterase showed similar effect both in donepezil and B. monniera treated groups. The content of aluminum was increased in all experimental groups, however, iron content was found increased in all groups except the B. monniera treated groups. Moreover, aluminum treated groups of rats exhibited significant changes in behavioral profiles but these changes were in both B. monniera and donepezil treated groups. The light microscopic and ultrastructural studies revealed damaged Purkinje's neurons and altered granular cell layer along with the increased accumulation of lipofuscin granules in aluminum treated animals. These changes were quite less pronounced in B. monniera group than that of donepezil and this may be due to the reduction of excess iron content by B. monniera. On the basis of our results it may be concluded that Al may be linked with cerebellar degeneration and neuromuscular disorders while Bacopa monniera extract helps in reversing these changes.

Effect of cooking method and rice type on arsenic concentration in cooked rice and the estimation of arsenic dietary intake in a rural village in West Bengal, India

Arsenic (As) contamination of rice plants can result in high total As concentrations (t-As) in cooked rice, especially if As-contaminated water is used for cooking. This study examines two variables: (1) the cooking method (water volume and inclusion of a washing step); and (2) the rice type (atab and boiled). Cooking water and raw atab and boiled rice contained 40 microg As l(-1) and 185 and 315 microg As kg(-1), respectively. In general, all cooking methods increased t-As from the levels in raw rice; however, raw boiled rice decreased its t-As by 12.7% when cooked by the traditional method, but increased by 15.9% or 23.5% when cooked by the intermediate or contemporary methods, respectively. Based on the best possible scenario (the traditional cooking method leading to the lowest level of contamination, and the atab rice type with the lowest As content), t-As daily intake was estimated to be 328 microg, which was twice the tolerable daily intake of 150 microg.

Arsenic speciation in food and estimation of the dietary intake of inorganic arsenic in a rural village of West Bengal, India

Arsenic (As) species were quantified by HPLC-HG-AFS in water and vegetables from a rural area of West Bengal (India). Inorganic species predominated in vegetables (including rice) and drinking water; in fact, inorganic arsenic (i-As) represented more than 80% of the total arsenic (t-As) content. To evaluate i-As intake in an arsenic affected rural village, a food survey was carried out on 129 people (69 men and 60 women). The data from the survey showed that the basic diet, of this rural population, was mainly rice and vegetables, representing more than 50% of their total daily food intake. During the periods when nonvegetarian foods (fish and meat) were scarce, the importance of rice increased, and rice alone represented more than 70% of the total daily food intake. The food analysis and the food questionnaires administrated led us to establish a daily intake of i-As of about 170 microg i-As day (-1), which was above the tolerable daily intake of 150 microg i-As day (-1), generally admitted. Our results clearly demonstrated that food is a very important source of i-As and that this source should never be forgotten in populations depending heavily on vegetables (mainly rice) for their diet.

Elimination of iodine deficiency disorders--current status in Purba Medinipur district of West Bengal, India

BACKGROUND AND OBJECTIVES

Towards sustainable elimination of iodine deficiency disorders (IDD), the existing programme needs to be monitored through recommended methods and indicators. Thus, we conducted the study to assess the current status of IDD in Purba Medinipur district, West Bengal.

METHODS

It was a community based cross-sectional study; undertaken from October 2006-April 2007. 2400 school children, aged 8-10 years were selected by '30 cluster' sampling technique. Indicators recommended by the WHO/UNICEF/ICCIDD were used. Subjects were clinically examined by standard palpation technique for goitre, urinary iodine excretion was estimated by wet digestion method and salt samples were tested by spot iodine testing kit.

RESULTS

The total goitre rate (TGR) was 19.7% (95% CI = 18.1-21.3 %) with grade I and grade II (visible goitre) being 16.7% and 3% respectively. Goitre prevalence did not differ by age but significant difference was observed in respect of sex. Median urinary iodine excretion level was 11.5 mcg/dL and none had value less than 5 mcg/dL. Only 50.4% of the salt samples tested were adequately iodised (> or = 15 ppm).

CONCLUSION

The district is in a phase of transition from iodine deficiency to iodine sufficiency as evident from the high goitre prevalence (19.7%) and median urinary iodine excretion (11.5 mcg/dL) within optimum limit. But, salt iodisation level far below the recommended goal highlights the need for intensified efforts towards successful transition.

Contribution of water and cooked rice to an estimation of the dietary intake of inorganic arsenic in a rural village of West Bengal, India

Arsenic contamination of rice plants by arsenic-polluted irrigation groundwater could result in high arsenic concentrations in cooked rice. The main objective of the study was to estimate the total and inorganic arsenic intakes in a rural population of West Bengal, India, through both drinking water and cooked rice. Simulated cooking of rice with different levels of arsenic species in the cooking water was carried out. The presence of arsenic in the cooking water was provided by four arsenic species (arsenite, arsenate, methylarsonate or dimethylarsinate) and at three total arsenic concentrations (50, 250 or 500 microg l(-1)). The results show that the arsenic concentration in cooked rice is always higher than that in raw rice and range from 227 to 1642 microg kg(-1). The cooking process did not change the arsenic speciation in rice. Cooked rice contributed a mean of 41% to the daily intake of inorganic arsenic. The daily inorganic arsenic intakes for water plus rice were 229, 1024 and 2000 microg day(-1) for initial arsenic concentrations in the cooking water of 50, 250 and 500 microg arsenic l(-1), respectively, compared with the tolerable daily intake which is 150 microg day(-1).

Characterization of Vibrio cholerae O1 ElTor typing phage S5

S5 (ATCC No. 51352-B2), a Vibrio cholerae O1 ElTor typing phage was characterized. The growth characteristics and inactivation kinetics (thermal, UV and pH) of this lytic phage were investigated. Phage morphology was examined by electron microscopy and was classified as belonging to the family Podoviridae. The S5 phage genome is shown to be a linear double-stranded 39-kb-long DNA as determined by electron microscopy and restriction digestion. Partial denaturation maps were constructed and were used to show that the DNA is non-permuted and terminally redundant. The replication origin of this T7-like phage was visualized by electron microscopy. The polarity of packaging of S5 DNA in the phage head was determined. SDS-PAGE of phage S5 shows two major structural polypeptides of 50 and 42 kDa. A 3D structure of the phage head was reconstructed at a resolution of 37 A using Cryo-EM and a single-particle reconstruction technique.

Multiorgan involvement due to cytomegalovirus infection in AIDS

Cytomegalovirus (CMV) infection is a relatively late complication of AIDS. Like other viruses contributing to co-morbidity of HIV infection, cytomegalovirus has the propensity to cause multiorgan involvement. We report the case of a 34-year-old seropositive man who presented with bilateral lower limb weakness and symptomatic pallor. He was already on antiretroviral drugs for a month prior to presentation. Detailed clinical examination and laboratory investigations revealed cytomegalovirus polyradiculoneuropathy associated with bone marrow dysplasia. Dysplasia of haematopoeitic cell lines occurs in 30% to 70% of HIV infected patients, and is often indistinguishable from myelodysplastic syndrome. However, in our case, the bone marrow picture reverted back to normal with treatment of the CMV infection, pointing to a possible role of CMV as the causative agent of bone marrow dysplasia. Moreover, CMV has been incriminated as a pathogen producing the immune reconstitution inflammatory syndrome. The onset of the disease in our case one month after initiation of HAART strongly raises the possibility of this being a case of CMV related IRIS. This is the first reported case where IRIS has presented with CMV polyradiculoneuropathy and bone marrow dysplasia. We would like to highlight that in today's era of HIV care, clinicians should be aware of the possibility of multiorgan involvement by CMV, for appropriate management of this disease in the background of AIDS.

Novel disulphide esters of carbothioic acid as potent, non-detergent spermicides with low toxicity to Lactobacillus and HeLa cells in vitro

BACKGROUND

The design, synthesis, characterization and evaluation of a novel series of non-detergent spermicides has led to the discovery of two unique molecules (DSE-36 and DSE-37) that were approximately 25 times more potent spermicides than nonoxynol-9 (N-9).

METHODS

Normal human spermatozoa were used to assess the spermicidal activity (Sander-Cramer Assay), the effect on sperm-membrane integrity [hypo-osmotic swelling test (HOST)], supravital staining and scanning electron microscopy (SEM) and the induction of apoptosis [fluorescein isothiocyanate (FITC) Annexin-V and JC-1 labelling using flow cytometry] by the new class of compounds. HeLa and Lactobacillus cultures were used to assess the cytotoxicity of compounds and their compatibility to normal vaginal flora, respectively.

RESULTS

Compounds DSE-36 and DSE-37 exhibited a strong spermicidal activity [minimum effective concentration (MEC) = 0.002%], which was approximately 25 times more potent than that of N-9 and Sapindus saponins (MEC = 0.05%). As compared with surfactants, DSE-36 and DSE-37 were found to be safer at MEC towards the growth and survival of Lactobacilli and HeLa cells in vitro and to have a milder effect on sperm plasma membrane. At EC(50) both induced apoptosis in sperm cells as characterized by increased labelling with Annexin-V and decreased polarization of sperm mitochondria.

CONCLUSION

Preliminary studies have revealed that in sharp contrast to the non-specific surfactant action of N-9, DSE-36 and DSE-37 have a highly potent, mechanism-based, detrimental action on human sperm. The unique ability of these non-detergent molecules to selectively kill sperm and spare Lactobacilli and HeLa cells at MEC values much lower than that required for N-9 indicates their potential as superior ingredients for formulation into microbicidal contraceptives.

Heavy metals in water of the rivers Hooghly and Haldi at Haldia and their impact on fish

The paper deals with the measurement of five heavy metals viz., Cd, Cu, Mn, Pb and Zn in water of the rivers Hooghly and Haldi at Haldia during June 1999 to October 2002. The industrial effluent out fall (OF) at Patikhali, Haldia was also taken as sampling site along with above out fall (AOF) and below out fall (BOF) sites. Most of the metals exhibited their least concentration at the sampling site above the Haldia industrial area of river Hooghly. The average concentrations of the studied metals were Cd 2-14, Cu 5-19, Mn 8-88, Pb 17-41 and Zn 22-37 microg l(-1). Comparison of the data with the Criterion Continuous Concentration (CCC) of USA revealed that Cd, Cu and Pb were the pollutants present at alarming level to disturb the aquatic life process in the zone. The effect was found to reflect on the tissue level aberrations in the residential fishes. The other two metals viz., Mn and Zn were probably less harmful to the aquatic ecosystem. In India, necessity is felt to develop the CCC values, which will be more appropriate for protection of aquatic environment than comparing with drinking water standards.