Characterization of native microalgal strains for their chromium bioaccumulation potential: phytoplankton response in polluted habitats

Due to its various uses, Cr contamination has become widespread in a diverse array of environments. The present study was carried out during 2007-2008 to investigate the accumulation potential of metals (Cr, Cu, Fe, Mn, Ni and Zn) and metalloid (As) by green (GA) and blue green (BGA) microalgae growing naturally in selected Cr-contaminated sites in districts Unnao and Kanpur (Uttar Pradesh, India). This investigation is a preliminary work to identify suitable native microalgae for biomonitoring and phytoremediation purposes. A total of 22 GA and 11 BGA were encountered in three seasons (summer, rainy and winter). Among these, the accumulation potential was evaluated in high biomass producing strains of BGA (three) and GA (nine). The maximum accumulation of Cr was shown by Phormedium bohneri (8550 microg g(-1)dw) followed by Oscillatoria tenuis (7354 microg g(-1)dw), Chlamydomonas angulosa (5325 microg g(-1)dw), Ulothrix tenuissima (4564 microg g(-1)dw), and Oscillatoria nigra (1862 microg g(-1)dw); all of which demonstrated a transfer factor of >10% for Cr. The results also indicate that the phytoplankton diversity was modified by Cr pollution. BGA represented the dominant community where Cr concentration was higher (11.84 and 2.27 mg L(-1)) (r=0.695), whereas GA showed negative correlation with respect to Cr concentration (r=-0.567). In conclusion, different algal species were able to grow in Cr-contaminated sites and to accumulate significant amounts of Cr with a high transfer factor.

Antioxidant defense mechanism in hydroponically grown Zea mays seedlings under moderate lead stress

The present study was designed to study the process of stress adaptation in roots and shoot of Zea mays seedlings grown under hydroponic conditions during exposure to lead (Pb) (0-200 microM) for 1-7 d. The alterations in growth and in the level of various biochemical parameters were accessed vis-à-vis Pb accumulation. The accumulation of Pb increased in a concentration-duration-dependent manner, however its translocation from root to shoot was low. At the same time, the level of malondialdehyde (MDA) increased with increasing Pb concentration. However, growth parameters, such as dry weight and root length did not show a significant decline to any of the Pb concentrations. In addition, the level of photosynthetic pigments decreased only upon exposure to high Pb concentrations. These results suggested an alleviation of the stress that was presumably being achieved by antioxidants viz., superoxide dismutase (SOD) and catalase (CAT) as well as ascorbic acid (AsA), which increased linearly with increasing Pb levels and exposure time. However, the level of non-protein thiols (NP-SH) in roots, in general, showed a decline beyond 4d that could be attributed to their consumption for the purpose of Pb detoxification. In conclusion, Zea mays can be used as an indicator species for Pb, and the various antioxidants might play a key role in the detoxification of Pb induced toxic effects.

Targeting Aldose Reductase: A Novel Strategy in Treating Endocrine Resistance Using Combination Therapy

Breast cancer is the most commonly diagnosed form of cancer in women. Among breast cancer patients about 2/3 are initially hormone sensitive or estrogen receptor (ER) positive and respond to endocrine therapy. Aromatase inhibitors (AI's) are superior class of hormonal therapeutic agents effectively control ER positive breast cancer in postmenopausal women. Acquired resistance to AI's is expected to be an emerging serious problem in clinics and recent studies have shown that tumors use adaptive signaling mechanisms to overcome AI sensitivity. Thus there is an urgent need for newer treatment modalities. Combination of endocrine and non endocrine agents that block these signaling pathways may prevent or delay the adaptive mechanism and thereby onset of resistance to hormonal therapy. In our study we have found that Fidarestat, an aldose reductase (enzyme which catalyzes the rate limiting step of glucose to fructose or sorbitol formation in polyol pathway) inhibitor effectively re-sensitize letrozole resistant LTLT-Ca breast cancer cells to letrozole. 1µM of fidarestat + 1uM letrozole was found very effective in inducing maximum cell death in LTLT-Ca cells when compared to fidarestat alone. The combination treatment not only restored ER-α levels but also down regulated HER2/MAPK signaling proteins. Aldose reductase siRNA (100nM)- treated MCF-7/Aro and MCF-7 cells upregulated ER-α in western blot and ER-functionality assays. On the other hand in aldose reductase-siRNA- treated LTLT-Ca cells, ER-α levels were down- regulated as in fidarestat treatment. Pretreatment of LTLT-Ca with fidarestat for one week showed reduced proliferation of cells and the effect was maintained until four passages with 1µM letrozole alone. Fidarestat treatment up-regulated E2-mediated transcription in LTLT-Ca cells. In order to enhance the efficacy and targeted delivery of fidarestat in LTLT–Ca cells we have used a nanoparticle-based therapeutic formulation. Folate receptor, highly expressed on epithelial carcinomas, could be a potential molecular target for tumor selective drug delivery. Physcio-chemically well characterized Fidarestat–folate nanoparticles (FFNP's) were prepared to increase the tumor selective intracellular delivery. FFNP's were found superior in exerting cytotoxicity when compared to fidarestat alone. Combination therapy was equally effective in controlling LTLT-Ca cell growth using xenograft model. Taken together, the increased glucose metabolism in LTLT-Ca cells may be critically contributing to chemotherapeutic resistance by increasing drug metabolism and decreasing uptake. Hence targeting aldose reductase in endocrine resistance may be attractive alternative to increase the sensitivity of hormonal therapy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 67.

Notch1 regulates the functional contribution of RhoC to cervical carcinoma progression

BACKGROUND

The role of Notch signalling in human epithelial cancers is of immense interest. In this study, we examine the interplay between Notch signalling and RhoC, a well-established molecular factor in metastasis. By linking the function of Notch and RhoC, we further strengthen the notion that there is a pro-oncogenic role of Notch signalling in human cervical cancers.

METHODS

RhoC protein expression in cervical carcinoma cell lines was assessed by western blotting. Using CaSki and SiHa cells (cervical carcinoma cells lines), we show that RhoC contributes to wound healing, invasion and migration, anoikis resistance, colony formation, in vitro tube formation and tumour formation. Immunohistochemical studies were carried out to assess the co-expression of RhoC, pAkt and Notch1 in clinical sections.

RESULTS

An assessment of the changes associated with epithelial-to-mesenchymal transition (EMT) shows that both Notch1 and RhoC have similar phenotypic contribution to EMT. Rho activity assessment on Notch1 inhibition with DAPT shows decreased RhoC activity. We further show that constitutively active RhoC rescues the phenotypic effect of Notch1 inactivation, and a comparison of Notch1 with RhoC expression shows an overlap between the two proteins in the same areas of the tissue.

CONCLUSION

This study has provided evidence to suggest that RhoC is an effector of Notch1 in cervical carcinoma.

Risk-factors and strategies for control of carcinoma cervix in India: hospital based cytological screening experience of 35 years

PURPOSE

Role of risk factors in cervical carcinogenesis and strategies for control of the disease have been assessed from the accumulated cytological data, derived from 35 years of hospital-based screening in Lucknow, North India.

MATERIALS AND METHODS

A total of 36,484 women have been cytologically screened during a span of 35 years (April 1971 - June 2005) in the Gynaecology out patient department (OPD) of Queen Mary's Hospital.

RESULTS

The frequency of Squamous Intraepithelial Lesion (SIL) and carcinoma was found to be 7.2% and 0.6%, respectively, in the present study. The study revealed high age and parity as a predominant factor in cervical carcinogenesis, while viral sexually transmitted disease (STDs) -human papilloma virus (HPV) and Herpes simplex virus (HSV) were also largely associated with SIL cases. The study emphasized great value of clinically downstaging the cervical cancer by detecting cervical cancer in the early stage. The study also revealed a significant difference in the frequency of SIL in symptomatic and asymptomatic women.

CONCLUSION

Based on the analyzed data, it was felt that single lifetime screening, which appears to be the most feasible and affordable mode for control of carcinoma cervix in developing countries like India, should be carried out in all women of high parity irrespective of age (with three or more children) and in older women above the age of 40 years irrespective of parity.

Genotoxicity evaluation of hospital wastewaters

In hospitals a large variety of substances are in use for medical purposes such as diagnostics and research. After application, diagnostic agents, disinfectants and excreted non-metabolized pharmaceuticals by patients reach the wastewater. Indeed, some of the substances found in wastewaters are genotoxic and are suspected to be a possible cause of the cancers observed in the last decades. Genotoxicity tests are an excellent means to study the toxicity and the risk associated with these releases. This paper points out the areas of concern for hospital wastewater disposal and reports the findings of genotoxicity tests for hospital effluents from 3 major hospitals in Delhi, namely All India Institute of Medical Sciences, Apollo and Escorts. Mutagenicity of hospital wastewaters from effluent treatment plants (before and after treatment) was studied. The results of this study show that the genotoxicity of hospital wastewaters is highly reduced after the treatment process. This study calls for establishment of advanced and effective effluent treatment plants in the hospitals, which are merely dumping the wastewaters in the municipal sewerage system. The results of this study call for further detailed study in this area.

Natural killer cell immunotherapy for cancer: a new hope

Recently there has been a substantial gain in our understanding of the role NK-cells play in mediating innate host immune responses. Although NK cells have long been known to mediate antigen independent tumor cytotoxicity, the therapeutic potential of NK cell-based immunotherapy has yet to be realized. Manipulating the balance between inhibitory and activating NK receptor signals, sensitization of tumor target cells to NK cell-mediated apoptosis, and recent discoveries in NK-cell receptor biology have fueled translational research that has led to clinical trials investigating a number of novel methods to potentiate NK cytotoxicity against human malignancies.

Predictor Profile to assess Recurrence Phenomenon of Suicidal Incidents among Region Based Target Population

Suicidal attempts have a very significant effect on the society, and they also reflect on the efforts of the supporting health care and counseling facilities and the therapist involved. The impact of suicide is further magnified by the needs of persons who attempt suicide multiple times, requiring emergency health care and rehabilitation. Preventing such activities becomes a major task for the support providing agencies as soon as clients with such tendencies are identified. There are repetitive traits that can be observed during the therapeutic program among the high-risk group individuals, who are susceptible to this kind of activity and such traits indicate for a specific profile. The aim of the instrument is to prevent the occurrence of the repetitive suicidal attempts of the clients in Washington State, which has one of the highest suicide rates. This profile has been constructed on the various parameters recognized in the statistical analysis of the client pool in Washington State, who have been under treatment for their suicidal behavior. This predictor indicates the probability of clients who attempt suicides repetitively by matching the parameters of the profile with that of the client. Building a profile for the purpose of predicting behavior of this kind can strengthen the intervention strategies more comprehensively and reduce such incidents and health care requirements and expenses.

Resolvin D1 controls inflammation initiated by glutathione-lipid conjugates formed during oxidative stress

BACKGROUND AND PURPOSE

Inflammation is associated with oxidative stress and local generation of lipid peroxidation-derived aldehydes, such as 4-hydroxy-trans-2-nonenal (HNE). In most tissues, HNE is readily conjugated with glutathione and presently it is unknown whether glutathionyl-HNE (GS-HNE) plays a functional role in inflammation. Here, we sought to determine whether GS-HNE is a mediator of oxidative stress-initiated inflammation and if its actions can be regulated by the anti-inflammatory and pro-resolving lipid mediator, resolvin D1 (RvD1).

EXPERIMENTAL APPROACH

GS-HNE was administered intraperitoneally to mice and peritoneal lavages were assessed for leukocyte infiltration and lipid mediators were targeted by mediator-lipidomics. RvD1 was administered to mice treated with GS-HNE and leukocyte infiltration was assessed in the peritoneum. Superoxide production and CD11b modulation were measured in isolated human polymorphonuclear leukocytes incubated with GS-HNE.

KEY RESULTS

GS-HNE (1-10 microg) evoked infiltration of Gr-1(+) leukocytes into the peritoneum to form an inflammatory exudate. With isolated human polymorphonuclear leukocytes, GS-HNE stimulated both superoxide generation and CD11b expression. Among the lipid mediators, both cyclooxygenase- and lipoxygenase-derived pro-inflammatory eicosanoids, including prostaglandin E(2), leukotriene B(4) and cysteinyl leukotrienes, were generated in exudates of mice injected intraperitoneally with GS-HNE. RvD1, given i.v. in doses as low as 0.01-10.0 ng, sharply reduced GS-HNE-stimulated leukocyte infiltration ( approximately 30-70%).

CONCLUSIONS AND IMPLICATIONS

Glutathione conjugates of HNE, derived during oxidative stress, are pro-inflammatory in vivo. RvD1 protects against this oxidative stress-initiated inflammation.

Buckling in polymer monolayers: molecular-weight dependence

We present systematic investigations of buckling in Langmuir monolayers of polyvinyl acetate formed at the air-water interface. On compression the polymer monolayers are converted to a continuous membrane with a thickness of approximately 2-3 nm of well-defined periodicity, lambdab. Above a certain surface concentration the membrane undergoes a morphological transition buckling, leading to the formation of striped patterns. The periodicity seems to depend on molecular weight as per the predictions of the gravity-bending buckling formalism of Milner for fluidlike films on water. However anomalously low values of bending rigidity and Young's modulus are obtained using this formalism. Hence we have considered an alternative model of buckling-based solidlike films on viscoelastic substrates. The values of bending rigidity and Young's modulus obtained by this method, although lower than expected, are closer to the bulk values. Remarkably, no buckling is found to occur above a certain molecular weight. We have tried to explain the observed molecular-weight dependence in terms of the variation in isothermal compressive modulus of the monolayers with surface concentration as well as provided possible explanations for the obtained low values of mechanical properties similar to that observed for ultrathin polymer films.

Photogeneration of electrons in dust clouds in near space

This paper presents an investigation of electron density and electron temperature in a dust cloud, subject to radiation, which causes photoelectric emission of electrons. The analysis is based on charge neutrality and number and energy balance of electrons. Appropriate expressions for the photoelectric emission and mean energy of emitted photoelectrons have been employed. The parametric relationship, corresponding to dust of stainless steel (as an illustration) in the near space environment, with dominant Lyman alpha (1215.7 A) radiation in the extreme ultraviolet part of the spectrum, has been investigated.

Complex dynamics in polymer nanocomposites

Polymer nanocomposites offer the potential to create a new type of hybrid material with unique thermal, optical, or electrical properties. Understanding their structure, phase behavior, and dynamics is crucial for realizing such potentials. In this work we provide an experimental insight into the dynamics of such composites in terms of the temperature, wave vector, and volume fraction of nanoparticles, using multispeckle synchrotron x-ray photon correlation spectroscopy measurements on gold nanoparticles embedded in polymethylmethacrylate. Detailed analysis of the intermediate scattering functions reveals possible existence of an intrinsic length scale for dynamic heterogeneity in polymer nanocomposites similar to that seen in other soft materials like colloidal gels and glasses.

Progression of chronic pulmonary tuberculosis in mice intravenously infected with ethambutol resistant Mycobacterium tuberculosis

PURPOSE

Ethambutol (EMB) is an important first line drug, however little information on its molecular mechanism of resistance and pathogenicity of resistant isolates is available. Present work was designed to study virulence of the EMB resistant M. tuberculosis strains and the host responses in-vivo on infection of EMB resistant M. tuberculosis using Balb/c mouse model of infection.

METHODS

Three groups of Balb/c mice (female, age 4-6 wk; 21 mice in each group) were infected intravenously with 106 CFU of M. tuberculosis H37Rv and two EMB resistant clinical isolates. Age and sex matched control animals were mock inoculated with Middlebrook 7H9 broth alone. At 10, 20, 30, 40, 50, 60, and 70 days post-infection three animals from each group were sacrificed by cervical dislocation and lung tissue was collected for further analysis.

RESULTS

Infection with EMB resistant M. tuberculosis led to progressive and chronic disease with significantly high bacillary load (p=0.02). Massive infiltration and exacerbated lung pathology with increased expression of IFN-gamma and TNF-alpha was observed in lungs of mice infected with EMB resistant strains. The present study suggests that infection with EMB resistant M. tuberculosis leads to chronic infection with subsequent loss of lung function, bacterial persistence with elevated expression of TNF-alpha resulting in increased lung pathology.

CONCLUSION

These findings highlight that EMB resistant M. tuberculosis regulates host immune response differentially and its pathogenicity is different from drug sensitive strains of M. tuberculosis.

Cancer stem cells: an approach to identify newer therapeutic targets

Several studies have shown the existence of cancer stem cells and suggested that they might have a role to play in chemotherapy resistance and radioresistance. Their survival skills may be the contributing factor to incomplete remission of tumors and relapse of tumors periodically followed with metastasis. The irrefutable proof of existence of cancer stem cells in hematopoietic system made way for studies with solid tumors in quest for a similar phenomenon which may be exploited to tumor therapy. Advances have been made in this field and one is poised to utilize properties of the cancer stem cells to generate fresh drugs. Recent finding suggesting ROS related genes as one of the mechanisms by which the cancer stem cells can generate resistance is a hope towards new therapeutic avenues.

Phytoremediation efficiency of Portulaca tuberosa rox and Portulaca oleracea L. naturally growing in an industrial effluent irrigated area in Vadodra, Gujrat, India

Phytoremediation is a novel, solar-driven and cost-effective technology for the remediation of heavy metal contaminated environments through exploitation of plants ability to accumulate heavy metals in their harvestable shoot parts. In the present investigation, we collected plants of two species of Portulaca i.e. P. tuberosa and P. oleracea from field sites in Vadodra, Gujrat, India. At one site, field was being irrigated with industrial effluent while at other with tube well water. Analysis of heavy metals was performed in industrial effluent, tube well water, soils irrigated with them, and in different parts viz., roots, stem, leaves and flowers of the plant samples. Industrial effluent and soil irrigated with it had very high level of heavy metals (Fe, Zn, Cd, Cr and As) as compared to the tube well water and soil irrigated with that. Plants of both the species growing in effluent irrigated soils showed high accumulation of metals in all plant parts with the maximum being in roots and the least in flowers. Interestingly, both species of Portulaca hyperaccumulated more than one heavy metal viz., Cd, Cr and As. The total shoot concentrations (microg g(-1) dw) of Cd, Cr and As in P. tuberosa were 1,571, 7,957 and 3,118, respectively while in P. oleracea, these were 1,128, 7,552 and 2,476, respectively. Portulaca plants have good biomass and high regeneration potential; hence appear to be suitable for the remediation of effluent (metal) contaminated areas.

Screening of native plants and algae growing on fly-ash affected areas near National Thermal Power Corporation, Tanda, Uttar Pradesh, India for accumulation of toxic heavy metals

The present investigation was carried out to screen native plants growing in fly-ash (FA) contaminated areas near National Thermal Power Corporation, Tanda, Uttar Pradesh, India with a view to using them for the eco-restoration of the area. A total number of 17 plants (9 aquatic, 6 terrestrial and 2 algal species) were collected and screened for heavy metal (Fe, Zn, Cu, Mo, B, Si, Al, Cr, Pb, Cd, Hg and As) accumulation. Differential accumulation of various heavy metals by different species of plants was observed. Hydrilla verticillata was found to be the most efficient metal accumulator among 9 aquatic plants, Eclipta alba among 6 terrestrial plants and Phormedium papyraceum between 2 algal species. In general, the maximum levels of most metals were found in terrestrial plants while the lowest in algal species. However, translocation of the metals from root to shoot was found to be higher in aquatic plants than terrestrial ones. These results suggest that various aquatic, terrestrial and algal species of plants may be used in a synergistic way to remediate and restore the FA contaminated areas.

Dietary adequacy in Asian Indians with HIV

Malnutrition is endemic in developing countries, which also bear the brunt of the human immunodeficiency virus (HIV) pandemic. HIV and its complications have a significant impact on nutritional status. Malnutrition and HIV have deleterious interactions. Dietary inadequacy is a major cause of malnutrition and few studies have been done to assess dietary adequacy in HIV-infected individuals and the factors affecting intake. Dietary intake of 71 consecutive patients was determined using 24-hour dietary recall, with the help of a questionnaire and a structured interview, and then compared with the recommended dietary allowances (RDA). The dietary intake of energy, total fat, fibre, vitamin C and iron were significantly less than the recommended RDA. There was no difference in protein intake. Only 5.7% of males and 16.7% of females reached the recommended energy allowance. The recommended protein allowance was reached by 43.4% males and 44.4% females and 41.5% males and 38.9% females consumed more than the upper limit of the recommended fat intake. Intake of major nutrients was also significantly less when compared to the national average intake. On bivariate analysis, the factors affecting these inadequacies were found to be annual per-capita income, dependency on another for livelihood, CD4 counts more than 200/cubic millimeter and absence of antiretroviral therapy. On multivariate analysis, only dependency on another was found to significantly influence energy intake. Dietary intake of many food constituents is significantly less in HIV patients than that recommended. Dietary counselling and efforts to improve food security are important in management of these patients.

Characterization of a new isolate of Pseudomonas fluorescens strain Psd as a potential biocontrol agent

AIMS

Evaluation of a new isolate of Pseudomonas fluorescens for its biocontrol properties.

METHODS AND RESULTS

Strain Psd identified as Ps. fluorescens, produces secondary metabolites that are toxic to some plant-pathogenic fungi. Inhibition of fungal growth of Fusarium oxysporum and Verticillium dahliae in the presence of bacterial culture filtrate provided the first clue to its biocontrol properties. In order to determine the basis for antifungal properties, antibiotics were extracted and analysed by TLC. Both pyrrolnitrin and phenazines could be detected in the culture of Psd. Presence of response regulator gene gacA of the two component regulatory system (GacS/GacA) was established by PCR amplification and sequencing. Sequence comparison of gacA justified the taxonomic position of this strain among the known members of Pseudomonadaceae. Synthesis of other compounds like toxic lipodepsipeptide, siderophores, and HCN was also confirmed by appropriate biochemical tests.

CONCLUSION

Characterization of strain Psd by various biochemical/plate tests followed by chromatographic identification of antibiotics, demonstrates its multifunctional biocontrol property. Response regulator gene gacA provides an additional genetic marker for the phylogenetic studies.

SIGNIFICANCE AND IMPACT OF THE STUDY

Ps. fluorescens strain Psd with its multifunctional biocontrol property can be used to bioprotect the crop plants from phytopathogens.

Do patients with low volume prostate cancer have prostate specific antigen recurrence following radical prostatectomy?

Aims:

The objective of this study was to determine the incidence of prostate specific antigen (PSA) relapse in patients with low volume prostate cancer following radical prostatectomy.

Methods:

Between 1993 and 2001, 50 of 717 patients had total tumour volumes of less than 0.5 cm3 following radical prostatectomy. Biochemical recurrence was defined as two consecutive values of serum PSA levels of 0.2 ng/ml or greater.

Results:

Median follow-up of the 50 patients was 58 months. In five of the 50 patients (10%), PSA recurrence was observed. All of these five cases had Gleason score of 3+3 (well and/or moderately differentiated), organ confined and surgical margin negative tumours. In three of the five cases, capsular incision resulted in benign glands extending into the surgical margin.

Conclusions:

Five of 50 cases had PSA failure. In three of the five patients, benign glands located in the margin could explain the “PSA recurrence”. However, in the other two patients, none of the pathological parameters correlated with measurable PSA levels. The explanation for their PSA failure is unclear.