Circulating microRNA profiling identifies microRNAs linked to prediabetes associated with alcohol dependence syndrome

BACKGROUND

MicroRNAs are abundant in serum and have emerged as important regulators of gene expression, implicating them in a wide range of diseases. The purpose of this study was to discover and validate serum miRNAs in prediabetes associated with alcohol dependence syndrome (ADS).

METHOD

Serum samples from ADS patients with or without prediabetes and normoglycemic controls were subjected to microarray. Validation of identified candidate miRNAs was performed by RT-qPCR. Additionally, GO and KEGG pathway analyses were carried out to uncover target genes anticipated to be controlled by the candidate miRNAs.

RESULTS

Notably, 198, and 172 miRNAs were differentially expressed in ADS-patients with or without prediabetes compared to healthy controls, and 7 miRNAs in ADS-patients with prediabetes compared to ADS-normoglycemic patients, respectively. Furthermore, hsa-miR-320b and hsa-miR-3135b were differentially expressed exclusively in ADS-patients with prediabetes, and this was further validated. Interestingly, GO and KEGG pathway analysis revealed that genes predicted to be modulated by the candidates were considerably enriched in numerous diabetes-related biological processes and pathways.

CONCLUSION

Our findings revealed that ADS-patients with or without prediabetes have different sets of miRNAs compared to normoglycemic healthy subjects. We propose serum hsa-miR-320b and hsa-miR-3135b as potential biomarkers for the diagnosis of prediabetes in ADS-patients.

Depression among rheumatoid arthritis patients and barriers to seeking professional help: An observational study

Background

A few studies have reported the association of rheumatoid arthritis (RA) with emotional changes including anxiety and depression. There is a paucity of Indian studies in this area.

Aim

To assess depression and its correlates in diagnosed cases of RA.

Materials and Methods

This was a cross-sectional and hospital-based study. A total of 70 patients with RA fulfilled the inclusion and exclusion criteria. Their demographic characteristics were recorded. They were individually assessed with the Clinical Disease Activity Index, Numerical Pain Rating Scale, Barriers to Access Care Evaluation, and Beck Depression Inventory. Statistical analysis was undertaken with SPSS.

Results

In the patients with RA the prevalence of depression was 44.2%. Analysis revealed that there was a significant positive correlation between depression with the severity of RA. Barriers to help-seeking were mainly attitudinal rather than stigma-related or instrumental barriers.

Conclusion

In the RA patients, the prevalence of depression was 44.2%. Clinical disease activity and the pain index were higher in patients with depression.

Neurobiological underpinnings of emotions

Emotion is a stirred-up state caused by physiological changes occurring as a response to some event and which tends to maintain or abolish the causative event. Understanding the neuroanatomical basis of the genesis and control of emotions is quintessential in understanding how biology affects the mind and in turn, helps in understanding our own nature. We present a short communication explaining the neurological basis of emotions.

Mental health impact of COVID-19 among health-care workers: An exposure-based cross-sectional study

BACKGROUND

Health-care workers (HCWs) in COVID-19 pandemic have faced the major impact in providing care to infected persons. Most of the studies on mental health impact among HCW have not incorporated paramedical staff. Furthermore, they have not compared psychological morbidity among HCW on the basis of high COVID exposure (HCE) and low COVID exposure (LCE). To address the above gap, this study aimed at evaluating mental health impact among HCW and its associated risk factors.

MATERIALS AND METHODS

Consecutive 200 HCWs each in the HCE and LCE groups (between the age group of 18 and 60 years) were enrolled from two tertiary care hospitals providing COVID-19 treatment from August 1, 2020. After collection of sociodemographic data, participants were administered Impact of Event Scale-Revised, Patient Health Questionnaire-9, and Generalized Anxiety Disorder-7 Scale.

RESULTS

The difference in stress, depression, and anxiety symptom scores between the HCE and LCE groups was not statistically significant. Multiple regression analysis revealed that female sex was associated with higher scores in all the three domains. The effect remained significant even after adjusting for effect of other risk factors.

CONCLUSION

HCE or LCE was associated with similar impact in terms of stress, depression, and anxiety among HCWs. Female HCWs had a higher prevalence of stress, depression, and anxiety. Doctors, nurses, and paramedics had a similar prevalence of stress, depression, and anxiety when odds were adjusted.

Assessment of depression, anxiety and stress in COVID-19 infected individuals and their families

Background

Pandemics have been associated with widespread psychological distress in the normal population due to quarantine and lockdown, however there are only few studies on psychiatric symptoms in COVID infected patients and their families. This study was planned to assess the depressive, anxiety and stress symptoms in individuals and their families infected with COVID19, during current pandemic.

Methods

A cross-sectional, observational study was conducted on hospitalised, COVID infected patients and their immediate family members. Ninety-three, COVID patients and fifty-four family members were studied through Google forms which contained socio-demographic proforma and Depression Anxiety Stress Scale-21 (DASS21). Collected data was tabulated to assess depression, anxiety and stress symptoms in the given population and study their relation with various sociodemographic variables.

Results

Almost one-third of the sample showed increased score on depression and anxiety subscales and one-fifth on stress subscales. 30–45% of the family members studied had higher score on either of the subset. There was also a high correlation between the scores of depression, anxiety and stress subset in the study sample.

Conclusion

This study, reflects high magnitude of depression, anxiety and stress symptoms in these patients and their families which alert us to the need for definitive interventions in these affected individuals.

Stress induced modifications in photosystem II electron transport, oxidative status, and expression pattern of acc D and rbc L genes in an oleaginous microalga Desmodesmus sp

The study aimed at understanding the biochemical and molecular level modifications in Desmodesmus sp. under lipid inducing stress conditions. The low-temperature (5 °C) incubation and nitrogen starvation reduced the PS II electron transport in microalga with a maximum reduction of 50-57% in ET₀/ABS values. The PS II electron transport recovered in UV treated cultures after an initial reduction of 87-93% in ET₀/ABS values. A 2.7-4.4 fold increase in ROS and MDA levels was observed under low-temperature incubation, and nitrogen starvation. The UV treatment caused 1.3-2.4 fold higher ROS and MDA levels than control. The low-temperature incubated, nitrogen starved, and UV treated cultures showed 2.4-4 fold higher acc D gene expression. A higher rbc L gene expression was observed under low-temperature stress. The study showed modifications in PS II electron transport, oxidative status, and expression of acc D and rbc L genes under stress conditions.

Role of various lifestyle and behavioral strategies in positive mental health across a preventive to therapeutic continuum

There is growing interest in lifestyle and behavioral strategies not only in prevention but also in the management of psychiatric morbidity. Available literature in this direction was accessed, and the role of various lifestyle and behavioral factors was explored. There is strong evidence of the role of good sleep, nutritious diet, exercise, social connectedness, enhanced self-esteem, sense of purpose in life, resilience, mindfulness, and environmental mastery in the promotion of mental well-being and prevention and management of psychiatric disorders. There is a significant scope of lifestyle and behavioral intervention in ensuring positive mental health spanning from preventive to therapeutic dimension.

Workplace based assessment: A review of available tools and their relevance

Workplace-based assessment (WPBA) appears to be a promising tool for more comprehensive assessment of the learners. Relevant literature in this direction was collated and analyzed for its relevance, salience, and merit. Many WPBA tools are being used by various educational institutions which spans across multiple domains and over the entire duration of the workplace learning. It caters to holistic assessment with structured measures, real-time feedback, and continuous professional development. It is being used more for formative assessment and has limited utility in summative assessment as on date. WPBA tools have promising prospect in bringing novelty, objectivity, and holistic approach in assessment.

Strategies for enhancement of alpha-linolenic acid rich lipids in Desmodesmus sp. without compromising the biomass production

The indigenous freshwater microalga Desmodesmus sp. produces ALA rich lipids (about 23%). The phytohormones (DAH and KIN; 0.5 mg L^-1) increased the biomass yield and lipid content of microalga by 1.4-1.7 fold. Mixotrophic cultivation (500 mM glucose and 100 mM sodium acetate) enhanced the biomass yield and lipid content by 1.8-2.7 fold. The sodium azide (1.0 mM) led to a 1.5 fold and 1.7 fold enhancement in the lipid content and ALA fraction of total fatty acids, respectively without affecting the biomass yield. The low temperature (5 °C) as the second stage of cultivation enhanced the ALA fraction of total fatty acids by 1.2-1.5 fold for untreated, phytohormone supplemented and mixotrophic cultures, without affecting the biomass yield. These cultivation strategies could, therefore, be used for enhancement of ALA rich lipids in microalgae without compromising the biomass production.

Enhanced accumulation of alpha-linolenic acid rich lipids in indigenous freshwater microalga Desmodesmus sp.: The effect of low-temperature on nutrient replete, UV treated and nutrient stressed cultures

The indigenous microalga, Desmodesmus sp. produced alpha-linolenic acid (ALA) rich lipids in response to low temperature and UV treatment. Incubation at 5 °C showed a 1.5 fold increase in lipid content (34% w/w) with 44% ALA fraction of total fatty acids. The UV treatment (UV 60 min) exhibited a 1.4 fold increase in biomass productivity and 1.6 fold increase in lipid content (37% w/w) with ALA fraction as 31% of total fatty acids. The nitrogen stress enhanced the lipid content (39% w/w) with a reduced ALA fraction (18%) of total fatty acids. The UV treated cultures (UV 40 and 60 min) on incubation at 5 °C showed maximum lipid accumulation (59 to 62% w/w) with ALA fraction of total fatty acids as 39 to 42%. The incubation of nutrient-replete and UV treated cultures at low-temperature could therefore be used for the production of ALA-rich lipids in microalgae.

Human microglia and astrocytes constitutively express the neurokinin-1 receptor and functionally respond to substance P

Background

The tachykinin substance P (SP) is recognized to exacerbate inflammation at peripheral sites via its target receptor, neurokinin 1 receptor (NK-1R), expressed by leukocytes. More recently, SP/NK-1R interactions have been associated with severe neuroinflammation and neuronal damage. We have previously demonstrated that NK-1R antagonists can limit neuroinflammatory damage in a mouse model of bacterial meningitis. Furthermore, we have since shown that these agents can attenuate bacteria-induced neuronal and glial inflammatory mediator production in nonhuman primate (NHP) brain explants and isolated neuronal cells, and following in vivo infection.

Methods

In the present study, we have assessed the ability of NHP brain explants, primary human microglia and astrocytes, and immortalized human glial cell lines to express NK-1R isoforms. We have utilized RT-PCR, immunoblot analysis, immunofluorescent microscopy, and/or flow cytometric analysis, to quantify NK-1R expression in each, at rest, or following bacterial challenge. Furthermore, we have assessed the ability of human microglia to respond to SP by immunoblot analysis of NF-kB nuclear translocation and determined the ability of this neuropeptide to augment inflammatory cytokine release and neurotoxic mediator production by human astrocytes using an ELISA and a neuronal cell toxicity assay, respectively.

Results

We demonstrate that human microglial and astrocytic cells as well as NHP brain tissue constitutively express robust levels of the full-length NK-1R isoform. In addition, we demonstrate that the expression of NK-1R by human astrocytes can be further elevated following exposure to disparate bacterial pathogens or their components. Importantly, we have demonstrated that NK-1R is functional in both human microglia and astrocytes and show that SP can augment the inflammatory and/or neurotoxic immune responses of glial cells to disparate and clinically relevant bacterial pathogens.

Conclusions

The robust constitutive and functional expression of the full-length NK-1R isoform by human microglia and astrocytes, and the ability of SP to augment inflammatory signaling pathways and mediator production by these cells, support the contention that SP/NK-1R interactions play a significant role in the damaging neuroinflammation associated with conditions such as bacterial meningitis.

Growth and biochemical characteristics of an indigenous freshwater microalga, Scenedesmus obtusus, cultivated in an airlift photobioreactor: effect of reactor hydrodynamics, light intensity, and photoperiod

The freshwater green algae, Scenedesmus obtusus, was cultivated in a 3.4 L airlift photobioreactor. The hydrodynamic parameters were estimated at different inlet gas flow rates (1, 2, 3, and 4 LPM) and their subsequent impact on the growth and biochemical characteristics of microalgae was studied. The biomass concentration and productivity increased with an increase in flow rates from 1 to 4 LPM. A maximum of 0.07 g L^-1 day^-1 productivity of biomass was attained at 3 LPM. An increase of total carbohydrate content from 19.6 to 26.4% was noticed with increment in the inlet flow rate of gas from 1 to 4 LPM. Major variations in total fatty acid content were not observed. The impact of light irradiance on growth and biochemical characteristics of S. obtusus was also evaluated. A maximum biomass productivity of 0.103 g L^-1 day^-1 was attained at an illumination of 150 μmol m^-2 s^-1 under continuous light. The major fatty acids reported were palmitic acid (C16:0), α-linolenic acid (C18:3), linoleic acid (C18:2), and oleic acid (C18:1). Biodiesel properties of the microalgae were estimated under various culture conditions. The light profile inside the airlift reactor was experimentally measured and the predictive modelling of light profile was also attempted.

Fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor A (VEGFA) synergistically promote steroidogenesis and survival of cultured buffalo granulosa cells

The present study investigated the combined effect of fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor A (VEGF-A) on estradiol (E₂) secretion and relative abundance of mRNA for aromatase enzyme (CYP19A1), proliferating cell nuclear antigen (PCNA) and BCL-2 associated X protein (BAX) in cultured buffalo granulosa cells (GCs). Follicles were isolated and classified into four groups based on size and E₂ concentration in follicular fluid (FF): Small, 4-6mm diameter, E₂<0.5ng/ml; Medium, 7-9mm, E₂=0.5-5ng/ml; Large, 10-13mm, E₂=5-40ng/ml; Preovulatory (PFs), >14mm, E₂>180ng/ml. The GCs of PF were cultured in 24 well cell culture plates and allowed to become 75-80% confluent. Then cultured GCs were treated with FGF2 (200ng/ml) and VEGF-A (100ng/ml) separately and in combination for three incubation periods (24, 48 and 72h). Estradiol secretion was greater in GCs treated with FGF2+VEGF-A compared to FGF2 or VEGF-A at all incubation periods and was greatest (P<0.05) at 72h of incubation. The relative abundance of CYP19A1 and PCNA mRNA were relatively consistent with the amount E₂ secretion. In contrast, the relative abundance of Bax mRNA was less in GCs treated with the combination of FGF2 and VEGF-A as compared to either FGF2 or VEGF-A alone and the least concentration (P<0.05) was at 72h of incubation. Findings with use of immunocytochemistry of cells treated with these factors were consistent to the relative abundance of mRNA transcript for the factor. The present findings indicate that FGF2 and VEGF-A may function in a synergistic manner to promote steroidogenesis and survival of cultured buffalo GCs.

Removal of nutrients and organic pollution load from pulp and paper mill effluent by microalgae in outdoor open pond

A mixed culture of microalgae, containing two Scenedesmus species, was analysed to determine its potential in coupling of pulp and paper mill effluent treatment and microalgal cultivation. Laboratory studies suggested that 60% concentration of wastewater was optimum for microalgal cultivation. A maximum of 82% and 75% removal of BOD and COD respectively was achieved with microalgal cultivation in outdoor open pond. By the end of the cultivation period, 65% removal of NO3-N and 71.29% removal of PO4-P was observed. The fatty acid composition of mixed microalgal culture cultivated with effluent showed the palmitic acid, oleic acid, linoleic acid and α-linolenic acid as major fatty acids. The results obtained suggest that pulp and paper mill effluent could be used effectively for cultivation of microalgae to minimise the freshwater and nutrient requirements.

Nonhealing Wounds—A Therapeutic Dilemma

Chronic wounds of the lower extremity are a therapeutic dilemma. In India, chronic wounds are caused by factors other than impaired circulation and diabetes, which account for most of this clinical problem in Western societies. A study of 2 topical agents, placental extract and phenytoin powder, is presented in this paper. One hundred fifty patients were randomly assigned to these treatments or to saline dressings (control). It was observed that patients receiving active topical treatments responded better than those in the control group. The importance of this finding should be viewed with the perspective that these topical treatments are inexpensive and easily available in India. The study also piloted measurements of angiogenic responses in 1 group, and the findings encourage further exploration with the technique and topical agent.

Evaluation of indigenous fresh water microalga Scenedesmus obtusus for feed and fuel applications: Effect of carbon dioxide, light and nutrient sources on growth and biochemical characteristics

Scenedesmus obtusus, a freshwater microalga, was evaluated for its growth and biochemical characteristics under various culture conditions. S. obtusus was tolerant at all tested CO2 concentrations up to 20%. Among the different nitrogen sources, urea showed enhanced biomass productivities up to 2-fold compared to control, where the nitrogen source was sodium nitrate. Light intensity and photoperiod had a significant effect on growth rate and biomass productivity. The growth rate was observed maximum under continuous light exposure at the light intensities, 30μmolm(-2)sec(-1) and 60μmolm(-2)sec(-1) The species was able to tolerate the salinity levels up to 25mM NaCl, where, the increase in the concentration of NaCl suppressed the growth. Ammonium acetate and glycine showed better growth rate and biomass productivity indicating mixotrophic ability of S. obtusus. Supplementation of acetate and bicarbonate significantly enhanced the biomass productivity. Biodiesel properties of S. obtusus cultivated at various culture conditions were estimated.

Triple-acting Lytic Enzyme Treatment of Drug-Resistant and Intracellular Staphylococcus aureus

Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over used conventional antibiotics. Here we describe engineered triple-acting staphylolytic peptidoglycan hydrolases wherein three unique antimicrobial activities from two parental proteins are combined into a single fusion protein. This effectively reduces the incidence of resistant strain development. The fusion protein reduced colonization by Staphylococcus aureus in a rat nasal colonization model, surpassing the efficacy of either parental protein. Modification of a triple-acting lytic construct with a protein transduction domain significantly enhanced both biofilm eradication and the ability to kill intracellular S. aureus as demonstrated in cultured mammary epithelial cells and in a mouse model of staphylococcal mastitis. Interestingly, the protein transduction domain was not necessary for reducing the intracellular pathogens in cultured osteoblasts or in two mouse models of osteomyelitis, highlighting the vagaries of exactly how protein transduction domains facilitate protein uptake. Bacterial cell wall degrading enzyme antimicrobials can be engineered to enhance their value as potent therapeutics.

Defatted algal biomass as a non-conventional low-cost adsorbent: surface characterization and methylene blue adsorption characteristics

The present study investigates the use of defatted algal biomass (DAB) as a non-conventional low cost adsorbent. The maximum adsorption capacity of biomass (raw, defatted and sulfuric acid pretreated DAB) was determined by liquid phase adsorption studies in batch mode for the removal of methylene blue present at various concentrations (1, 2, 3, 4, and 5 mg L(-1)) from aqueous solutions. The data was well fitted with Langmuir and Freundlich isotherms. The maximum adsorption capacity for raw, defatted and sulfuric acid pretreated DAB was found to be 6.0, 7.73 and 7.80 mg g(-1), respectively. The specific surface area of raw, defatted and sulfuric acid pretreated DAB was estimated to be 14.70, 18.94, and 19.10 m(2) g(-1), respectively. To evaluate the kinetic mechanism that controls the adsorption process, pseudo-first order, pseudo-second order, intraparticle diffusion and particle diffusion has been tested. The data fitted quite well with pseudo-second order kinetic model.

Astrocytes produce IL-19 in response to bacterial challenge and are sensitive to the immunosuppressive effects of this IL-10 family member

There is growing appreciation that resident glial cells can initiate and/or regulate inflammation following trauma or infection in the central nervous system (CNS). We have previously demonstrated the ability of microglia and astrocytes to respond to bacterial pathogens or their products by rapid production of inflammatory mediators, followed by the production of the immunosuppressive cytokine interleukin (IL)−10. IL-19, another member of the IL-10 family of cytokines, has been studied in the context of a number of inflammatory conditions in the periphery and is known to modulate immune cell activity. In the present study, we demonstrate the constitutive and/or inducible expression of IL-19 and its cognate receptor subunits, IL-19Rα and IL-19Rβ (also known as IL-20R1 and IL-20R2, and IL-20RA and IL-20RB), in mouse brain tissue, and by primary murine and human astrocytes. We also provide evidence for the presence of a novel truncated IL-19Rα transcript variant in mouse brain tissue, but not glial cells, that shows reduced expression following bacterial infection. Importantly, IL-19R functionality in glia is indicated by the ability of IL-19 to regulate signaling component expression in these cells. Furthermore, while IL-19 itself had no effect on glial cytokine production, IL-19 treatment of bacterially infected or Toll-like receptor ligand stimulated astrocytes significantly attenuated pro-inflammatory cytokine production. The bacterially induced production of IL-19 by these resident CNS cells, the constitutive expression of its cognate receptor subunits, and the immunomodulatory effects of this cytokine, suggest a novel mechanism by which astrocytes can regulate CNS inflammation.

Statistical optimization of thermal pretreatment conditions for enhanced biomethane production from defatted algal biomass

The present study analyzes the effect of thermal pretreatment for enhancing the biomethane potential of defatted algal biomass of Scenedesmus dimorphus through statistically guided experimental design. To this end, defatted microalgal biomass at various concentrations (1, 3 and 5 g L(-1)) was pretreated at elevated temperatures (100, 120 and 150°C) for 20, 40 and 60 min. The solubilised TOC was favourably enhanced up to 71 mg L(-1) after pretreatment at a temperature of 150°C for reaction time of 60 min. The methane yield was substantially enhanced (up to 60%) and could be correlated with an increase in organic matter solubilisation and enhanced biodegradability via thermal pretreatment. The optimisation of the integrated thermal pretreatment-biomethanation process resulted in up to 1.6-fold increase in methane yield.

Localized rotational activation in the left atrium during human atrial fibrillation: relationship to complex fractionated atrial electrograms and low-voltage zones

BACKGROUND

In humans, the existence of rotors or reentrant sources maintaining atrial fibrillation (AF) and the underlying electroanatomic substrate has not been well defined.

OBJECTIVE

Our aim was to determine the prevalence of localized rotational activation (RotA) in the left atrium (LA) during human AF and whether complex fractionated atrial electrograms (CFAEs) or low-voltage areas colocalize with RotA sites.

METHODS

We prospectively studied 32 patients (mean age 57 ± 8 years; 88% with persistent AF) undergoing AF catheter ablation. Bipolar electrograms were recorded for 2.5 seconds during AF using a roving 20-pole circular catheter in the LA. RotA was defined as sequential temporal activation of bipoles around the circular catheter. Bipolar electrogram fractionation index and bipolar voltage were used to define CFAEs and low-voltage areas, respectively.

RESULTS

In 21 (66%) patients, 47 RotA sites were identified. Few (9%) lasted 2.5 seconds (cycle length 183 ± 6 ms), while the majority (91%) were nonsustained (duration 610 ± 288 ms; cycle length 149 ± 11 ms). RotA was most common in the pulmonary vein antrum (71%) and posterior LA (25%). CFAEs were recorded from 18% ± 12% of LA area, and most (92% ± 7%) were not associated with RotA sites. However, 85% of RotA sites contained CFAEs. Very low voltage (<0.1 mV) areas comprised 12% ± 10% of LA area and were present in 23% of RotA sites.

CONCLUSIONS

In patients with predominantly persistent AF, localized RotA is commonly present but tends to be transient (<1 second). Although most CFAEs do not colocalize with RotA sites, the high prevalence of CFAEs and very low voltages within RotA sites may indicate slow conduction in diseased myocardium necessary for their maintenance.

Selection and evaluation of CO2 tolerant indigenous microalga Scenedesmus dimorphus for unsaturated fatty acid rich lipid production under different culture conditions

Five indigenous microalgal strains of Scenedesmus, Chlorococcum, Coelastrum, and Ankistrodesmus genera, isolated from Indian fresh water habitats, were studied for carbon-dioxide tolerance and its effect on growth, lipid and fatty acid profile. Scenedesmus dimorphus strain showed maximum growth (1.5 g/L) and lipid content (17.83% w/w) under CO2 supplementation, hence selected for detailed evaluation. The selected strain was alkaline adapted but tolerated (i) wide range of pH (5-11); (ii) elevated salinity levels (up to 100 mM, NaCl) with low biomass yields and increased carotenoids (19.34 mg/g biomass); (iii) elevated CO2 levels up to 15% v/v with enhancement in specific growth rate (0.137 d(-1)), biomass yield (1.57 g/L), lipid content (19.6% w/w) and CO2 biofixation rate (0.174 g L(-1) d(-1)). Unsaturated fatty acid content (alpha linolenic acid) increased with CO2 supplementation in the strain.

Psychiatric morbidity in asymptomatic human immunodeficiency virus patients

BACKGROUND

Psychiatric morbidity in human immunodeficiency virus (HIV) patients is being studied all over the world. There is paucity of Indian literature particularly in asymptomatic HIV individuals.

AIM

The aim of the following study is to establish the prevalence and the determinants of psychiatric morbidity in asymptomatic HIV patients.

MATERIALS AND METHODS

A cross-sectional study was undertaken to assess psychiatric morbidity as per ICD-10 dacryocystorhinostomy criteria in 100 consecutive asymptomatic seropositive HIV patients and an equal number of age, sex, education, economic and marital status matched HIV seronegative control. All subjects were assessed with the general health questionnaire (GHQ), mini mental status examination, hospital anxiety and depression scale (HADS) and sensation seeking scale (SSS) and the scores were analyzed statistically.

RESULTS

Asymptomatic HIV positive patients had significantly higher GHQ caseness and depression but not anxiety on HADS as compared to HIV seronegative controls. On SSS asymptomatic HIV seropositive subjects showed significant higher scores in thrill and adventure seeking, experience seeking and boredom susceptibility as compared to controls. HIV seropositive patients had significantly higher incidence of total psychiatric morbidity. Among the individual disorders, alcohol dependence syndrome, sexual dysfunction and adjustment disorder were significantly increased compared with HIV seronegative controls.

CONCLUSION

Psychiatric morbidity is higher in asymptomatic HIV patients when compared to HIV seronegative controls. Among the individual disorders, alcohol dependence syndrome, sexual dysfunction and adjustment disorder were significantly increased compared with HIV seronegative controls. High sensation seeking and substance abuse found in HIV seropositive patients may play a vital role in engaging in high-risk behavior resulting in this dreaded illness.

Alpha beta-crystallin expression and presentation following infection with murine gammaherpesvirus 68

Alpha beta-crystallin (CRYAB) is a small heat shock protein that can function as a molecular chaperone and has protective effects for cells undergoing a variety of stressors. Surprisingly, CRYAB has been identified as one of the dominant autoantigens in multiple sclerosis. It has been suggested that autoimmune mediated destruction of this small heat shock protein may limit its protective effects, thereby exacerbating inflammation and cellular damage during multiple sclerosis. It is not altogether clear how autoimmunity against CRYAB might develop, or whether there are environmental factors which might facilitate the presentation of this autoantigen to CD4+ T lymphocytes. In the present study, we utilized an animal model of an Epstein Barr Virus (EBV)-like infection, murine gammaherpesvirus 68 (HV-68), to question whether such a virus could modulate the expression of CRYAB by antigen presenting cells. Following exposure to HV-68 and several other stimuli, in vitro secretion of CRYAB and subsequent intracellular accumulation were observed in cultured macrophages and dendritic cells. Following infection of mice with this virus, it was possible to track CRYAB expression in the spleen and in antigen presenting cell subpopulations, as well as its secretion into the blood. Mice immunized with human CRYAB mounted a significant immune response against this heat shock protein. Further, dendritic cells that were exposed to HV-68 could stimulate CD4+ T cells from CRYAB immunized mice to secrete interferon gamma. Taken together these studies are consistent with the notion of a gammaherpesvirus-induced CRYAB response in professional antigen presenting cells in this mouse model.

The chemistry, pharmacologic, and therapeutic applications of Polyalthia longifolia

Medicinal plants are nature's gift to human beings to lead a disease-free, healthy life. They play a vital role in preserving our health. India is one of the most medicoculturally diverse countries in the world, where the medicinal plant sector is part of a time-honored tradition that is respected even today. Medicinal plants are believed to be much safer and proved as elixir in the treatment of various ailments. In our country, more than 2000 medicinal plants are recognized. Polyalthia longifolia cv. pendula (Annonaceae) is native to the drier regions of India and is locally known as “Ashoka” and is commonly cultivated in Pakistan and Sri Lanka. This plant is used as an antipyretic agent in indigenous systems of medicine. Pharmacologic studies on the bark and leaves of this plant show effective antimicrobial activity, cytotoxic function, antiulcer activity, hypoglycemic activity, and hypotensive effect. The present article includes the detailed exploration of pharmacologic properties of P. longifolia in an attempt to provide a direction for further research.

An expanded myeloid derived suppressor cell population does not play a role in gammaherpesvirus-exacerbated breast cancer metastases

Background

Mice latently infected with murine gammaherpesvirus 68 (HV-68) and transplanted with 4 T1 breast cancer cells developed exacerbated metastatic lesions when compared to controls. The mechanisms responsible for this viral-exacerbated disease were not clear. The ability of HV-68 infection to induce S100A8 and S100A9 production and to expand a population of CD11b+Gr-1+ cells suggested that increased numbers, or activity, of viral-expanded myeloid derived suppressor cells (MDSCs) might contribute to HV-68-associated metastatic breast cancer in this model. We questioned whether mock or HV-68 infected mice with significant breast cancer might have differences in the number and/or activity of MDSCs.

Methods

Myeloid-derived macrophages and dendritic cells were isolated from normal mice and cultured in vitro with HV-68 to assess S100A8 and S100A9 mRNA and protein expression. In vivo studies were performed using groups of mice that were mock treated or infected with HV-68. After viral latency was established, 4 T1 breast cancer cells were transplanted in mice. When primary breast tumors were present mice were euthanized and cells isolated for phenotyping of myeloid cell populations using FACS, and for ex vivo analysis of suppressor activity. Serum from these animals was also collected to quantify S100A8 and S100A9 levels.

Results

In vitro studies demonstrated that direct exposure of myeloid cells to HV-68 did not induce increased expression of S100A8 or S100A9 mRNAs or secreted protein. HV-68 infected mice with metastatic breast cancer disease had no increases in S100A8/A9 levels and no significant increases in the numbers or activation of CD11b+Gr-1+MDSCs when compared to mock treated mice with breast cancer.

Conclusions

Together these studies are consistent with the notion that expanded myeloid derived suppressor cells do not play a role in gammaherpesvirus-exacerbated breast cancer metastases. The mechanisms responsible for HV-68 induced exacerbation of metastatic breast cancer remain unclear.

Exacerbated metastatic disease in a mouse mammary tumor model following latent gammaherpesvirus infection

Background

Controversy exists as to the ability of human gammaherpesviruses to cause or exacerbate breast cancer disease in patients. The difficulty in conducting definitive human studies can be overcome by investigating developing breast cancer in a mouse model. In this study, we utilized mice latently infected with murine gammaherpesvirus 68 (HV-68) to question whether such a viral burden could exacerbate metastatic breast cancer disease using a mouse mammary tumor model.

Results

Mice latently infected with HV-68 had a similar primary tumor burden, but much greater metastatic disease, when compared to mock treated mice given the transplantable tumor, 4 T1. This was true for lung lesions, as well as secondary tumor masses. Increased expression of pan-cytokeratin and VEGF-A in tumors from HV-68 infected mice was consistent with increased metastatic disease in these animals. Surprisingly, no viral particles could be cultured from tumor tissues, and the presence of viral DNA or RNA transcripts could not be detected in primary or secondary tumor tissues.

Conclusions

Latent HV-68 infection had no significant effect on the size of primary 4 T1 mammary tumors, but exacerbated the number of metastatic lung lesions and secondary tumors when compared to mock treated mice. Increased expression of the tumor marker, pan-cytokeratin, and VEGF-A in tumors of mice harboring latent virus was consistent with an exacerbated metastatic disease. Mechanisms responsible for this exacerbation are indirect, since no virus could be detected in cancerous tissues.

Murine gammaherpesvirus-68 expands, but does not activate, CD11b+ gr-1+ splenocytes in vivo

Background

Murine gammaherpesvirus 68 (HV-68) is an efficient pathogen, capable of infecting and establishing lifelong latency in rodents. While many studies have demonstrated the ability of this viral infection to modulate immune responses, a unifying mechanism for HV-68-induced subversion of a protective host response remains elusive. We questioned whether infection with HV-68 could expand a population of myeloid derived suppressor cells (MDSC) as one mechanism for altering protective immunity.

Methods

Mice were infected with HV-68, with viral latency being established in these animals. At varying times post-infection, cells were isolated for detection of viral genomes, phenotyping of myeloid cell populations, and ex vivo analysis of suppressor activity of myeloid cells.

Results

CD11b + Gr-1+ myeloid cells accumulated in the spleens, but not the bone marrow, of HV-68 infected mice. These cells were predominantly Gr-1+ Ly-6 G+, and could be found to contain viral genomes. Increased levels of serum S100A8/A9 produced during viral infection were consistent with the expansion of these CD11b + Gr-1+ myeloid cells. Despite their expansion, these cells exhibited no increased arginase 1 or iNOS activity, and did not have the ability to suppress anti-CD3 antibody activated T lymphocyte responses.

Conclusions

We concluded that HV-68 infection was capable of expanding a population of myeloid cells which were phenotypically similar to MDSC. However these cells were not sufficiently activated during the establishment of viral latency to actively suppress T cell responses.

A role for DNA-dependent activator of interferon regulatory factor in the recognition of herpes simplex virus type 1 by glial cells

BACKGROUND

The rapid onset of potentially lethal neuroinflammation is a defining feature of viral encephalitis. Microglia and astrocytes are likely to play a significant role in viral encephalitis pathophysiology as they are ideally positioned to respond to invading central nervous system (CNS) pathogens by producing key inflammatory mediators. Recently, DNA-dependent activator of IFN regulatory factor (DAI) has been reported to function as an intracellular sensor for DNA viruses. To date, the expression and functional role of DAI in the inflammatory responses of resident CNS cells to neurotropic DNA viruses has not been reported.

METHODS

Expression of DAI and its downstream effector molecules was determined in C57BL/6-derived microglia and astrocytes, either at rest or following exposure to herpes simplex virus type 1 (HSV-1) and/or murine gammaherpesvirus-68 (MHV-68), by immunoblot analysis. In addition, such expression was studied in ex vivo microglia/macrophages and astrocytes from uninfected animals or mice infected with HSV-1. Inflammatory cytokine production by glial cultures following transfection with a DAI specific ligand (B-DNA), or following HSV-1 challenge in the absence or presence of siRNA directed against DAI, was assessed by specific capture ELISA. The production of soluble neurotoxic mediators by HSV-1 infected glia following DAI knockdown was assessed by analysis of the susceptibility of neuron-like cells to conditioned glial media.

RESULTS

We show that isolated microglia and astrocytes constitutively express DAI and its effector molecules, and show that such expression is upregulated following DNA virus challenge. We demonstrate that these resident CNS cells express DAI in situ, and show that its expression is similarly elevated in a murine model of HSV-1 encephalitis. Importantly, we show B-DNA transfection can elicit inflammatory cytokine production by isolated glial cells and DAI knockdown can significantly reduce microglial and astrocyte responses to HSV-1. Finally, we demonstrate that HSV-1 challenged microglia and astrocytes release neurotoxic mediators and show that such production is significantly attenuated following DAI knockdown.

CONCLUSIONS

The functional expression of DAI by microglia and astrocytes may represent an important innate immune mechanism underlying the rapid and potentially lethal inflammation associated with neurotropic DNA virus infection.

Prophylactic and therapeutic targeting of the neurokinin-1 receptor limits neuroinflammation in a murine model of pneumococcal meningitis

There is increasing evidence that the tachykinin substance P (SP) can augment inflammatory immune responses within the CNS. We have recently demonstrated that resident CNS cells express high-affinity receptors for this neuropeptide (neurokinin-1 receptors [NK-1R]), and we have shown that SP can significantly augment glial inflammatory responses to clinically relevant Gram-negative bacteria. Furthermore, we provided evidence that endogenous SP/NK-1R interactions are an essential component in the initiation and/or progression of CNS inflammation following in vivo exposure to these pathogens. In this study, we demonstrate that SP similarly enhances inflammatory glial responses to the major Gram-positive causative agent of bacterial meningitis, Streptococcus pneumoniae, and show that endogenous SP/NK-1R interactions play a critical role in the development of CNS inflammation in an in vivo model of pneumococcal meningitis. Importantly, we provide the first demonstration, to our knowledge, that pharmacological targeting of the NK-1R not only prevents the development of damaging inflammation when administered prophylactically, but can also limit or reverse neuroinflammation associated with an established streptococcal CNS infection when delivered therapeutically. We show that an NK-1R antagonist attenuates increases in CNS inflammatory cytokine levels and decreases in immunosuppressive cytokine production associated with an ongoing S. pneumoniae infection. Furthermore, we demonstrate that such a therapeutic intervention reverses infection-associated gliosis and demyelination in the absence of changes in CNS bacterial burden. Together, these results suggest that targeting SP/NK-1R interactions is a strategy worthy of further study for the treatment of microbially induced neuroinflammation.

In vivo analysis of translation initiation sites in Plasmodium falciparum

Regulation of gene expression in the malaria parasite Plasmodium falciparum is tightly controlled and little is known about the many steps involved. One step i.e. translation initiation is also poorly understood and in P. falciparum, choice of the translation initiation site (TIS) is a critical decision largely due to the high frequency of AUGs in the relatively long 5' untranslated regions of parasite mRNAs. The sequences surrounding the TIS have a major role to play in translation initiation and this report evaluates these sequences by mutational analysis of the heat shock protein 86 gene, transient transfection and reporter assays in the parasite. We find that purines at the -3 and +4 positions are essential for efficient translation in P. falciparum, similar to other eukaryotes. Interestingly, a U at the -1 position results in 2.5-fold higher reporter activity compared to wild type. Certain classes of protein biosynthetic genes show higher frequencies of U at the -1 position, suggesting that these genes may exhibit higher levels of translation. This work defines the optimal sequences for TIS choice and has implications for the design of efficient expression vectors in an important human pathogen.

Causative agents of osteomyelitis induce death domain-containing TNF-related apoptosis-inducing ligand receptor expression on osteoblasts

Bacteria and their products are potent inducers of bone destruction. While inflammatory damage during conditions such as osteomyelitis is associated with increased formation and activity of bone-resorbing osteoclasts, it is likely that bone loss also results from the elimination of the cells responsible for matrix deposition. Consistent with this notion, we have previously demonstrated that bone-forming osteoblasts undergo apoptosis following bacterial challenge and that this cell death is due, at least in part, to the actions of TNF-related apoptosis-inducing ligand (TRAIL). In the present study, we demonstrate that primary osteoblasts constitutively express death domain containing TRAIL receptors. Importantly, we show that cell surface expression of the death-inducing receptors DR4 and DR5 on murine and human osteoblasts is restricted to cells infected with the principle causative agents of osteomyelitis, Staphylococcus aureus and Salmonella. In addition, we show that the robust constitutive production by osteoblasts of the decoy TRAIL receptor, OPG, is inhibited following bacterial infection. Finally, we report that while exogenous administration of TRAIL fails to activate apoptosis signaling pathways in uninfected osteoblasts, acute bacterial exposure sensitizes these cells to this ligand. Based upon these findings we suggest a model in which bacterially challenged osteoblasts express TRAIL while concomitantly decreasing the production of the decoy receptor OPG and upregulating cell surface death receptor expression. Such an increase in TRAIL bioavailability and induced sensitivity of infected osteoblasts to this ligand would result in apoptotic cell death of this bone-forming population, providing an additional mechanism underlying inflammatory bone loss during diseases such as osteomyelitis.

Characterization of retinoic acid-inducible gene-I expression in primary murine glia following exposure to vesicular stomatitis virus

Vesicular stomatitis virus (VSV) is a negative-sense single-stranded RNA virus that closely resembles its deadly cousin, rabies virus. In mice, VSV elicits a rapid and severe T cell-independent encephalitis, indicating that resident glial cells play an important role in the initiation of central nervous system (CNS) inflammation. Recently, retinoic acid-inducible gene I (RIG-I)-like helicases have been shown to function as intracellular pattern recognition receptors for replicative viral RNA motifs. In the present study, we demonstrate that the expression of two members of this RIG-I-like receptor family (RLR), RIG-I and melanoma differentiation-associated antigen 5 (MDA5), are elevated in mouse brain tissue following intranasal administration of VSV. Using isolated cultures of primary murine glial cells, we demonstrate that microglia and astrocytes constitutively express both RIG-I and MDA5 transcripts and protein. Importantly, we show that such expression is elevated following challenge with VSV or another negative-sense RNA virus, Sendai virus. The authors provide evidence that such induction is indirect and secondary to the production of soluble mediators by infected cells. Circumstantial evidence for the functional nature of RLR expression in glial cells comes from the observation that microglia express the RLR downstream effector molecule, interferon promoter stimulator-1, and demonstrate diminished levels of the negative RLR regulator, laboratory of genetics and physiology 2, following viral challenge. These findings raise the exciting possibility that RLR molecules play important roles in the detection of viral CNS pathogens and the initiation of protective immune responses or, alternatively, the progression of damaging inflammation within the brain.

NOD2 mediates inflammatory responses of primary murine glia to Streptococcus pneumoniae

It is now widely accepted that resident central nervous system (CNS) cells such as microglia and astrocytes initiate and/or augment inflammation following trauma or infection. However, the mechanisms by which glial cells perceive microbial challenges are only now becoming apparent. We have recently demonstrated that microglia and astrocytes constitutively express nucleotide-binding oligomerization domain-2 (NOD2), a member of the novel nucleotide-binding domain leucine-rich repeat region-containing family of proteins (NLR) that functions as an intracellular receptor for a minimal motif present in all bacterial peptidoglycans. Furthermore, we have shown that this NLR is essential for glial responses to gram-negative pathogens and in vivo CNS inflammation elicited by these organisms. In the present study, we have established that intact Streptococcus pneumoniae, the major causative agent for gram-positive bacterial meningitis in adults, is a potent stimulus for the activation of the pivotal inflammatory transcription factor NF-kB and production of inflammatory cytokines in primary murine microglia and astrocytes. We demonstrate that NOD2 is essential for the maximal responses of these cells to intact S. pneumoniae but not cellular lysates. Finally, we have shown that this cytosolic pattern recognition receptor is required for the elevated inflammatory mediator levels, astrogliosis, and demyelination, following in vivo administration of this gram-positive CNS pathogen. As such, we suggest that NOD2 plays a critical role in the establishment of the lethal inflammation associated with streptococcal meningitis.

NOD2 contributes to the inflammatory responses of primary murine microglia and astrocytes to Staphylococcus aureus

We have recently demonstrated that microglia and astrocytes express nucleotide-binding oligomerization domain-2 (NOD2), a novel cytosolic pattern recognition receptor for bacterial motifs, and we have shown that this intracellular receptor is essential for glial responses to Gram-negative pathogens. Here, we demonstrate that intact Staphylococcus aureus, a major Gram-positive causative agent of brain abscesses, activates the transcription factor NF-kappaB and is a potent stimulus for inflammatory cytokine production in primary murine microglia and astrocytes. Interestingly, we demonstrate that NOD2 is essential for maximal glial responses to intact S. aureus, but not cellular lysates. As such, this data indicates that NOD2 plays an important role in initiating inflammatory mediator production by resident brain cells following S. aureus infection and we suggest that this cytosolic receptor acts in conjunction with cell surface pattern recognition receptors to elicit maximal glial responses.

Differential roles for NOD2 in osteoblast inflammatory immune responses to bacterial pathogens of bone tissue

Osteoblasts produce an array of immune molecules following bacterial challenge that can contribute to inflammation and the recruitment of leukocytes to sites of infection during bone diseases such as osteomyelitis. However, the mechanisms by which osteoblasts perceive and respond to facultative intracellular pathogens such as Salmonella species and Staphylococcus aureus have not been determined. Recently, our laboratory has described the expression in osteoblasts of members of the nucleotide-binding domain leucine-rich repeat region containing family of proteins that include nucleotide-binding oligomerization domain-2 (NOD2), a molecule that functions as an intracellular receptor for bacterial peptidoglycans. In the present study, we demonstrate that NOD2 expression is required for select inflammatory mediator production by osteoblasts following infection with the invasive pathogen Salmonella. In contrast, we have found that the inflammatory immune responses of osteoblasts to the passively internalized bacterial species Staphylococcus aureus, heat-killed pathogenic Salmonella, a non-invasive Salmonella strain and specific Toll-like receptor ligands are not reduced in the absence of NOD2 expression but are, in fact, elevated. Based upon these findings, we suggest that NOD2 serves differential roles in osteoblasts, promoting inflammatory responses to invasive bacteria while tempering cell responses to extracellular and/or passively internalized bacterial species.

Vesicular stomatitis virus infects resident cells of the central nervous system and induces replication-dependent inflammatory responses

Vesicular stomatitis virus (VSV) infection of mice via intranasal administration results in a severe encephalitis with rapid activation and proliferation of microglia and astrocytes. We have recently shown that these glial cells express RIG-I and MDA5, cytosolic pattern recognition receptors for viral RNA. However, it is unclear whether VSV can replicate in glial cells or if such replication is required for their inflammatory responses. Here we demonstrate that primary microglia and astrocytes are permissive for VSV infection and limited productive replication. Importantly, we show that viral replication is required for robust inflammatory mediator production by these cells. Finally, we have confirmed that in vivo VSV administration can result in viral infection of glial cells in situ. These results suggest that viral replication within resident glial cells might play an important role in CNS inflammation following infection with VSV and possibly other neurotropic nonsegmented negative-strand RNA viruses.

Primary human astrocytes functionally express RIG-I, a member of the retinoic acid-inducible gene-I family of viral pattern recognition receptors (133.48)

Astrocytes are ideally positioned to detect and respond to invading pathogens of the CNS and previous studies have demonstrated the ability of these cells to produce key inflammatory mediators following exposure to members of the Mononegavirales order of viruses that are the causative agents of lethal human CNS diseases including rabies. However, the mechanisms by which resident cells of the CNS perceive such viral challenges have not been defined. Recently, several cytosolic DExD/H box RNA helicases have been described that can bind early viral replicative intermediates leading to the realization that retinoic acid-inducible gene I (RIG-I)-like helicases, such as RIG-I, function as intracellular receptors for RNA viruses. In the present study, we demonstrate that cultured primary human astrocytes constitutively express RIG-I receptor protein. Interestingly, such expression is rapidly elevated following exposure to vesicular stomatitis virus (VSV), a neurotropic rhabdovirus that closely resembles rabies virus. Evidence for the functional nature of RIG-I expression in human glial cells comes from the observation that this molecule associates with its downstream effector molecule, interferon promoter stimulator-1 (IPS-1), following VSV infection as assessed by co-immunoprecipitation techniques. Furthermore, we have confirmed that this molecule functions as an intracellular pattern recognition receptor in astrocytes by demonstrating that a putative ligand for RIG-I can elicit inflammatory cytokine production by this cell type. These findings raise the exciting possibility that RIG-I plays an important role in the detection of viral CNS pathogens and the initiation of protective immune responses or, alternatively, the progression of damaging inflammation within the brain.

Vesicular stomatitis virus infects primary murine microglia and astocytes and induces replication-dependent inflammatory cytokine production (133.47)

Vesicular stomatitis virus (VSV) is a rhabdovirus that closely resembles its deadly cousin, rabies virus. Intranasal inoculation of mice with VSV leads to infection of the central nervous system (CNS) and an acute encephalitis that results in a high rate of mortality similar to that observed during human rabies infections. Importantly, this encephalitis is accompanied by the rapid activation and proliferation of resident brain cells including microglia and astrocytes, suggesting a role for such cells in the initiation and/or progression of CNS inflammation. Our recent study showed that these glial cells express RIG-I and MDA5, cytosolic receptors for replicating RNA virus motifs. However, it is presently unclear whether microglia and astrocytes can harbor replicating VSV, or if such replication is required for the inflammatory immune responses of these resident CNS cells. In this study we demonstrate that primary murine microglia and astrocytes are permissive for VSV infection and replication. Importantly, active replication appears to be required for robust inflammatory mediator production as such responses were markedly lower in cells exposed to either inactivated or replication defective viral particles. Interestingly, this effect is not limited to neurotropic Mononegaviruses as the paramyxovirus, Sendai virus, can similarly infect glial cells and elicit inflammatory immune responses. Finally, we have confirmed that in vivo intranasal VSV administration results in viral infection and replication within mouse glial cells in situ. This study suggests that viral replication within resident glial cells could play a key role in the development of lethal CNS inflammation following neurotropic Mononegavirus infection.

NOD2 plays an important role in the inflammatory responses of microglia and astrocytes to bacterial CNS pathogens

While glial cells are recognized for their roles in maintaining neuronal function, there is growing appreciation that resident central nervous system (CNS) cells initiate and/or augment inflammation following trauma or infection. We have recently demonstrated that microglia and astrocytes constitutively express nucleotide-binding oligomerization domain-2 (NOD2), a member of the novel nucleotide-binding domain leucine-rich repeat region containing a family of proteins (NLR) that functions as an intracellular receptor for a minimal motif present in all bacterial peptidoglycans. In this study, we have confirmed the functional nature of NOD2 expression in astrocytes and microglia and begun to determine the relative contribution that this NLR makes in inflammatory CNS responses to clinically relevant bacterial pathogens. We demonstrate the increased association of NOD2 with its downstream effector molecule, Rip2 kinase, in primary cultures of murine microglia and astrocytes following exposure to bacterial antigens. We show that this cytosolic receptor underlies the ability of muramyl dipeptide to augment the production of inflammatory cytokines by glia following exposure to specific ligands for disparate Toll-like receptor homologues. In addition, we demonstrate that NOD2 is an important component in the in vitro inflammatory responses of resident glia to N. meningitidis and B. burgdorferi antigens. Finally, we have established that NOD2 is required, at least in part, for the astrogliosis, demyelination, behavioral changes, and elevated inflammatory cytokine levels observed following in vivo infection with these pathogens. As such, we have identified NOD2 as an important component in the generation of damaging CNS inflammation following bacterial infection.

Lifestyle, reproductive factors and risk of gallbladder cancer

INTRODUCTION

Lifestyle and dietary habits play an important role in carcinogenesis. Carcinoma of the gallbladder is no different. The present study was carried out to evaluate the roles of lifestyle, menstrual and reproductive factors in gallbladder cancer.

METHODS

A prospective case-control study involving 78 newly-diagnosed cases of carcinoma of the gallbladder and 78 age- and gender-matched controls with cholelithiasis were investigated for their lifestyle history, with an emphasis on habits with chewing betel nut and tobacco, alcohol consumption and smoking. Besides this, female patients were investigated for their menstrual and reproductive factors. Odds-ratio and significance were calculated.

RESULTS

A Hindu preponderance was seen. About half of the patients with carcinoma of the gallbladder and gallstone were either illiterate or had a very low level of education (primary or below). Religion, education, family income, chewing of tobacco as well as smoking were comparable. But numbers of chewing tobacco and smoking per day differed significantly. Alcohol was consumed by 11.6 percent of carcinoma and 4.1 percent of gallstone patients. Lower age of menarche, higher number of pregnancies and higher age at menopause had a significantly increased risk of gallbladder carcinogenesis. A significant difference in carcinogenesis was seen in the postmenopausal women compared with the menopausal group.

CONCLUSION

Carcinoma of the gallbladder was common in tobacco chewers. Females with lower age at menarche, higher number of pregnancies and childbirths and higher age at last childbirth had an increased risk of gallbladder cancer.

Neurogenic exacerbation of microglial and astrocyte responses to Neisseria meningitidis and Borrelia burgdorferi

Although glial cells are recognized for their roles in maintaining neuronal function, there is growing appreciation of the ability of resident CNS cells to initiate and/or augment inflammation following trauma or infection. The tachykinin, substance P (SP), is well known to augment inflammatory responses at peripheral sites and its presence throughout the CNS raises the possibility that this neuropeptide might serve a similar function within the brain. In support of this hypothesis, we have recently demonstrated the expression of high affinity receptors for SP (Neurokinin-1 (NK-1) receptors) on microglia and shown that this tachykinin can significantly elevate bacterially induced inflammatory prostanoid production by isolated cultures of these cells. In the present study, we demonstrate that endogenous SP/NK-1R interactions are an essential component in the initiation and/or progression of CNS inflammation in vivo following exposure to two clinically relevant bacterial CNS pathogens, Neisseria meningitidis and Borrelia burgdorferi. We show that in vivo elevations in inflammatory cytokine production and decreases in the production of an immunosuppressive cytokine are markedly attenuated in mice genetically deficient in the expression of the NK-1R or in mice treated with a specific NK-1R antagonist. Furthermore, we have used isolated cultures of microglia and astrocytes to demonstrate that SP can augment inflammatory cytokine production by these resident CNS cell types following exposure to either of these bacterial pathogens. Taken together, these studies indicate a potentially important role for neurogenic exacerbation of resident glial immune responses in CNS inflammatory diseases, such as bacterial meningitis.

Blood stage malaria antigens induce different activation-induced cell death programs in splenic CD4+T cells

CD4(+) T cells respond to antigen immunization through a process of activation, clonal expansion to generate activated effector T cells followed by activation-induced clonal deletion of the responding T cells. While loss of responding T cells in post-activation death by apoptosis is a major factor regulating immune homeostasis, the precise pathways involved in downsizing of Plasmodium falciparum antigen-induced T cell expansions are not well characterized. We report in this study that splenic CD4(+) T cells from mice immunized with nonreplicating immunogens like OVA or recombinant blood stage P. falciparum antigens, PfMSP-3 and PfMSP-1(19) or crude parasite antigen (PfAg) undergo sequential T cell activation, proliferation followed by activation-induced cell death (AICD) in a dose- and time-dependent manner after Ag restimulation. While PfMSP-3 and OVA-induced AICD was mediated through a death receptor-dependent apoptotic program, PfMSP-1(19) and PfAg-induced AICD was via a mechanism dependent on the activation of mitochondria apoptosis signalling pathway through Bax activation. These results provide insights into the mechanism through which two blood stage merozoite antigens trigger different apoptotic programs of AICD in splenic CD4(+) T cells.

Tudor domain proteins in protozoan parasites and characterization of Plasmodium falciparum tudor staphylococcal nuclease

RNA-binding proteins play key roles in post-transcriptional regulation of gene expression. In eukaryotic cells, a multitude of RNA-binding proteins with several RNA-binding domains/motifs have been described. Here, we show the existence of two Tudor domain containing proteins, a survival of motor neuron (SMN)-like protein and a Staphylococcus aureus nuclease homologue referred to as TSN, in Plasmodium and other protozoan parasites. Activity analysis shows that Plasmodium falciparum TSN (PfTSN) possesses nuclease activity and Tudor domain is the RNA-binding domain. A specific inhibitor of micrococcal nucleases, 3',5'-deoxythymidine bisphosphate (pdTp) inhibits the nuclease as well as RNA-binding activities of the protein. PfTSN shows a predominant nuclear localization. Treatment of P. falciparum with pdTp, inhibited in vitro growth of both chloroquine-sensitive and chloroquine-resistant strains of P. falciparum, while a four fold concentration of pdTp did not have any significant effect on the mammalian cell line, Huh-7D12. Altogether, these results suggest that PfTSN is an essential enzyme in the parasite's life cycle.

Alpha,beta-dehydrophenylalanine containing cecropin-melittin hybrid peptides: conformation and activity

Synthesis and conformational studies of a cecropin-melittin hybrid pentadecapeptide CA(1-7)MEL(2-9), and its three alpha, beta-dehydrophenylalanine (DeltaPhe) containing analogs in water-TFE mixtures are described. DeltaPhe is placed at strategic positions in order to preserve the amphipathicity of the molecule. The wild type CAMEL0 and its three analogs, containing one, two and three DeltaPhe residues namely CAMELDeltaPhe1, CAMELDeltaPhe2 and CAMELDeltaPhe3 respectively were synthesized in solid phase and their conformation determined by CD and NMR. CAMELDeltaPhe2 and CAMELDeltaPhe3 peptides exhibit the presence of 3(10)-helix and beta-turns in the former and only turns in the latter. CAMELDeltaPhe1 peptide was found to have a largely extended conformation. Antibacterial and hemolytic activities of the peptides were also evaluated. CAMELDeltaPhe2 peptide is maximally potent against both Staphylococcus aureus ATCC 259230 and Escherichia coli ATCC 11303. CAMELDeltaPhe1 with a single DeltaPhe at the center shows minimal hemolysis.

Immune Responses to Asexual Blood-Stages of Malaria Parasites

The blood stage of the malaria parasite's life cycle is responsible for all the clinical symptoms of malaria. The development of clinical disease is dependent on the interplay of the infecting parasite with the immune status and genetic background of the host. Following repeated exposure to malaria parasites, individuals residing in endemic areas develop immunity. Naturally acquired immunity provides protection against clinical disease, especially severe malaria and death from malaria, although sterilizing immunity is never achieved. Given the absence of antigen processing in erythrocytes, immunity to blood stage malaria parasites is primarily conferred by humoral immune responses. Cellular and innate immune responses play a role in controlling parasite growth but may also contribute to malaria pathology. Here, we analyze the natural humoral immune responses acquired by individuals residing in P. falciparum endemic areas and review their role in providing protection against malaria. In addition, we review the dual potential of cellular and innate immune responses to control parasite multiplication and promote pathology.