25 research outputs found

    A flow cytometry based method for studying embryogenesis and immune reactivity to embryogenic stages in filarial parasites

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    BACKGROUND: In the absence of intermediate animal hosts, the process of embryogenesis leading to fecundity of adult female filarial worms is very critical for persistence of these obligate parasites in human communities. Embryogenesis in adult female filarial parasites involves fertilization of eggs or oocytes by sperms and their subsequent development into motile microfilariae inside the uterine cavity of worms. Development of assays for monitoring embryogenesis in adult female worms is a critical requirement in filariasis research – filarial worms are known to harbour endosymbionts such as Wolbachia which play a significant role in fecundity. Tetracycline or doxycycline treatment of the infected hosts effectively eliminates the endosymbionts resulting in inhibition of embryogenesis in female worms. Currently, inhibition of embryogenesis in adult filarial worms can be monitored only by microscopic examination of in vitro harvested intrauterine stages. METHODS: Adult female filarial worms of bovine filarial parasites, Setaria digitata were collected from the peritoneum of infected animals and intrauterine stages were harvested in culture medium and were analyzed for forward and side scatter by flowcytometry using a BD FACS Calibur. Different populations were gated, sorted and identified by phase microscopy. Binding of biotinylated lectins to intra uterine stages was monitored using FITC labeled Avidin and monitored by flow cytometry of gated populations. Similarly, binding of antibodies in human filarial sera to intrauterine stages was monitored using FITC labeled anti-human immunoglobulins. RESULTS: The forward and side scatter for intrauterine stages delineated 3 distinct populations labeled as R1, R2 and R3. The three populations were sorted and identified to be a) fully stretched microfilariae, b) early and c) late developmental stages of eggs respectively. Lectins such as Wheat Germ agglutinin or Concanavalin-A were found to bind strongly to egg stages and less prominently to intra-uterine microfilariae. Similarly the binding of antibodies in filarial sera to the three intra-uterine stages could also be precisely quantified. CONCLUSION: The manuscript reports a novel flow cytometry based method to monitor progression of embryogenesis in adult filarial worms. Apart from relative quantification of different intra uterine developmental stages, the assay allows quantitative binding of lectins and antibodies to each of the intrauterine stages. It may now be possible to quantify levels of antibodies in infected and immune hosts to monitor anti-fecundity immunity in filariasis – the assay can thus be used as a powerful tool for drug development and in immunological studies in human and experimental filariasis

    Caspase Dependent Programmed Cell Death in Developing Embryos: A Potential Target for Therapeutic Intervention against Pathogenic Nematodes

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    Pathogenic nematodes currently infect billions of people around the world and pose serious challenges to the economic welfare and public health in most developing countries. At present, limitations of existing therapies warrant identification of new anti-parasitic drugs/drug targets to effectively treat and control neglected tropical diseases [NTD] caused by nematode pathogens. The current gold standard for measuring/screening drug effectiveness against most helminth parasites is in-vitro assessment of motility of parasites/larvae and larval development assays which fails to provide any conclusive idea about the precise mechanism of death of parasitic worms or their larval stages. Given the huge load of parasites or their larval stages in an infected host, a compound which shows promise in in-vitro/motility screening assays but induces necrotic death in parasites/larvae will be of limited use, as it may elicit severe inflammatory response in infected hosts. In this context, the present study, which demonstrates induction of apoptotic death in developing embryos of a pathogenic nematode as a potential drug target for the first time, and provides scope for high throughput screening of pharmacological agents for their apoptogenicity against nematode embryos, is a step forward to develop novel anti-parasitic measures to challenge NTD caused by nematode pathogens

    3, 3β€²5 Triiodo L Thyronine Induces Apoptosis in Human Breast Cancer MCF-7cells, Repressing SMP30 Expression through Negative Thyroid Response Elements

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    Thyroid hormones regulate cell proliferation, differentiation as well as apoptosis. However molecular mechanism underlying apoptosis as a result of thyroid hormone signaling is poorly understood. The antiapoptotic role of Senescence Marker Protein-30 (SMP30) has been characterized in response to varieties of stimuli as well as in knock out model. Our earlier data suggest that thyroid hormone 3, 3'5 Triiodo L Thyronine (T(3)), represses SMP30 in rat liver.In highly metastatic MCF-7, human breast cancer cell line T3 treatment repressed SMP30 expression leading to enhanced apoptosis. Analysis by flow cytometry and other techniques revealed that overexpression and silencing of SMP30 in MCF-7 resulted in decelerated and accelerated apoptosis respectively. In order to identify the cis-acting elements involved in this regulation, we have analyzed hormone responsiveness of transiently transfected hSMP30 promoter deletion reporter vectors in MCF-7 cells. As opposed to the expected epigenetic outcome, thyroid hormone down regulated hSMP30 promoter activity despite enhanced recruitment of acetylated H3 on thyroid response elements (TREs). From the stand point of established epigenetic concept we have categorised these two TREs as negative response elements. Our attempt of siRNA mediated silencing of TRΞ², reduced the fold of repression of SMP30 gene expression. In presence of thyroid hormone, Trichostatin- A (TSA), which is a Histone deacetylase (HDAC) inhibitor further inhibited SMP30 promoter activity. The above findings are in support of categorisation of both the thyroid response element as negative response elements as usually TSA should have reversed the repressions.This is the first report of novel mechanistic insights into the remarkable downregulation of SMP30 gene expression by thyroid hormone which in turn induces apoptosis in MCF-7 human breast cancer cells. We believe that our study represents a good ground for future effort to develop new therapeutic approaches to challenge the progression of breast cancer

    Neurodevelopmental disorders in children aged 2-9 years: Population-based burden estimates across five regions in India.

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    BACKGROUND: Neurodevelopmental disorders (NDDs) compromise the development and attainment of full social and economic potential at individual, family, community, and country levels. Paucity of data on NDDs slows down policy and programmatic action in most developing countries despite perceived high burden. METHODS AND FINDINGS: We assessed 3,964 children (with almost equal number of boys and girls distributed in 2-<6 and 6-9 year age categories) identified from five geographically diverse populations in India using cluster sampling technique (probability proportionate to population size). These were from the North-Central, i.e., Palwal (N = 998; all rural, 16.4% non-Hindu, 25.3% from scheduled caste/tribe [SC-ST] [these are considered underserved communities who are eligible for affirmative action]); North, i.e., Kangra (N = 997; 91.6% rural, 3.7% non-Hindu, 25.3% SC-ST); East, i.e., Dhenkanal (N = 981; 89.8% rural, 1.2% non-Hindu, 38.0% SC-ST); South, i.e., Hyderabad (N = 495; all urban, 25.7% non-Hindu, 27.3% SC-ST) and West, i.e., North Goa (N = 493; 68.0% rural, 11.4% non-Hindu, 18.5% SC-ST). All children were assessed for vision impairment (VI), epilepsy (Epi), neuromotor impairments including cerebral palsy (NMI-CP), hearing impairment (HI), speech and language disorders, autism spectrum disorders (ASDs), and intellectual disability (ID). Furthermore, 6-9-year-old children were also assessed for attention deficit hyperactivity disorder (ADHD) and learning disorders (LDs). We standardized sample characteristics as per Census of India 2011 to arrive at district level and all-sites-pooled estimates. Site-specific prevalence of any of seven NDDs in 2-<6 year olds ranged from 2.9% (95% CI 1.6-5.5) to 18.7% (95% CI 14.7-23.6), and for any of nine NDDs in the 6-9-year-old children, from 6.5% (95% CI 4.6-9.1) to 18.5% (95% CI 15.3-22.3). Two or more NDDs were present in 0.4% (95% CI 0.1-1.7) to 4.3% (95% CI 2.2-8.2) in the younger age category and 0.7% (95% CI 0.2-2.0) to 5.3% (95% CI 3.3-8.2) in the older age category. All-site-pooled estimates for NDDs were 9.2% (95% CI 7.5-11.2) and 13.6% (95% CI 11.3-16.2) in children of 2-<6 and 6-9 year age categories, respectively, without significant difference according to gender, rural/urban residence, or religion; almost one-fifth of these children had more than one NDD. The pooled estimates for prevalence increased by up to three percentage points when these were adjusted for national rates of stunting or low birth weight (LBW). HI, ID, speech and language disorders, Epi, and LDs were the common NDDs across sites. Upon risk modelling, noninstitutional delivery, history of perinatal asphyxia, neonatal illness, postnatal neurological/brain infections, stunting, LBW/prematurity, and older age category (6-9 year) were significantly associated with NDDs. The study sample was underrepresentative of stunting and LBW and had a 15.6% refusal. These factors could be contributing to underestimation of the true NDD burden in our population. CONCLUSIONS: The study identifies NDDs in children aged 2-9 years as a significant public health burden for India. HI was higher than and ASD prevalence comparable to the published global literature. Most risk factors of NDDs were modifiable and amenable to public health interventions

    Acetylation of the proto-oncogene EVI1 abrogates Bcl-xL promoter binding and induces apoptosis.

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    EVI1 (Ecotropic Viral Integration site I), which was originally identified as a myeloid transforming gene by means of retroviral insertional mutagenesis in mouse leukemia, encodes a nuclear DNA binding zinc finger protein. The presence of zinc fingers that are able to bind to specific sequences of DNA suggests that EVI1 is a transcriptional regulator; however, except a few, target genes of EVI1 are poorly functionally identified thus far. In this study we provide evidence that EVI1 directly induces the expression of Bcl-xL through the first set of zinc finger and thereby inhibits apoptosis. ChIP analysis showed that EVI1 binds to the Bcl-xL promoter in HT-29 cells, a colon carcinoma cell line, which expresses EVI1. The observation is also supported by the fact that EVI1 siRNA treated HT-29 cells, shows a down regulation of Bcl-xL expression and that over expression of EVI1 results in the induction of the Bcl-xL reporter construct. A set of EVI1 positive chronic myeloid leukemia (CML) samples also showed higher Bcl-xL expression with respect to EVI1 negative samples. Interestingly, co-expression of EVI1 with wild type, but not with dominant-negative form of PCAF, abolishes the effect of EVI1 on Bcl-xL, indicating that acetylation of EVI1 abrogates its ability not only to bind Bcl-xL promoter but also alleviate Bcl-xL activity. Finally we have shown that EVI1 expression regulates apoptosis in HT-29 cells, which is abrogated when HT-29 cells are transfected with EVI1 siRNA or PCAF. The result for the first time shows a direct pathway by which EVI1 can protect cells from apoptosis and also demonstrates that the pathway can be reversed when EVI1 is acetylated

    Study on DMPA as postpartum contraception in a tertiary care hospital

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    Background: Injectable Depomedroxyprogesterone acetate(DMPA) is a very safe, convenient, highly effective,reversible,long-acting postpartum contraception without affecting lactation. Objectives: To find out side effects, continuation rate and reasons for discontinuation of DMPA used as postpartum contraception.Material and methods:This Prospective study was carried out on 120 women. Intramuscular DMPA administered every 3 month after 6 weeks postpartum. Data in relation to age, parity, side effects, continuation rate and reasons for discontinuation was statistically analysed using SPSS software and Microsoft Excel. Results were expressed in term of numbers and percentages. Results: 43.33% and 33.33% were in the age group of 21-25 and 26-30 years respectively. 53.34% were Primipara.Irregular bleeding was the most common side effect seen in 36.67%. 20% had secondary amenorrhoea. 7.5% noticed weight gain. 5.83% complaint of headache and 1.67% had acne. Majority (61.66%) discontinued DMPA after first and second dose of injection. 20.84% and 17.5% discontinued after third and fourth dose respectively. Most common reason for discontinuation was its side effects, seen in 68.34%. 16.66% were lost to follow up.15% switched over to another contraception. Most of the users were satisfied with their lactation. No significant alteration of blood pressure was found among DMPA users. No serious adverse reaction was noticed and none of the women became pregnant during DMPA use. Conclusion: Injectable DMPA was found to be safe and highly effective postpartum contraception without any adverse affect on lactation. Pre-use counselling on expected side effects along with regular follow-up increases the acceptance and continuation rate

    EVI1 binds to Bcl-xL promoter element.

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    <p>A. A multiple sequence alignment of parts of Bcl-xL 2<sup>nd</sup> exon from different species are shown and the binding site is underlined. Genbank accession numbers of each of Bcl-xL sequence from different species that were used in the alignment analysis are as follows, <i>Canis familiaris</i>: NM_001003072.1, <i>Homo sapiens</i>: NM_138578.1, <i>Rattus rattus</i>: NM_001033670.1, <i>Gallus gallus</i>: NM_001025304.1, <i>Danio rerio</i>: NM_131807.1, <i>Felis catus</i>: NM_001009228.1, <i>Bos taurus</i>: NM_001077486.2 and <i>Mus musculus</i>: NM_009743.4. B. Nuclear extracts from EVI1 transfected 293T cells were incubated with a radiolabelled, double-stranded oligo designed from the EVI1 binding site in Bcl-xL promoter. EVI1 binds to Bcl-xL (lane 1) as shown by an arrow whereas a mutated probe failed to show any binding (lane 2). Lane 3 shows only the empty vector transfected cells and lane 6 shows the probe without any nuclear lysate. Increasing amount of specific cold competitor at 30Γ— molar excess of radiolabelled probe (lane 4) failed to inhibit the binding of EVI1 to Bcl-xL promoter however a cold competitor at 50Γ— molar excess of radiolabelled probe (lane 5) inhibited binding of EVI1 to Bcl-xL promoter. C. ChIP analysis shows the occupancy of EVI1 on the Bcl-xL promoter <i>in vivo</i>. After cross linking and chromatin fractionations DNA protein complexes were incubated with EVI1 antibody and the complex were processed as per the manufacturer's instructions (Imgenex India Pvt. Ltd.). Eluted DNA samples were then analyzed by PCR using specific primers flanking the EVI1 binding region. A band of 170 bp was observed only in HT-29 cells (lane 3) and no band was observed with IgG (lane 2) or with primers taken from the upstream region (lane 6). Marker (M) and the input controls for both regions are as shown (lane 1 and lane 4). D. ChIP was performed on 293T cells transfected with empty vector or EVI1 construct. For this assay flag-CMV-vector, flag-EVI1 wild type (Wt), flag- EVI1-Ξ”A (EVI1-Ξ”24 to 239) and flag-EVI1-Ξ”D (EVI1-Ξ”735 to 812) constructs were transfected separately in 293T cells. After processing as described above PCR showed an amplification of 170 bp when cells were transfected with EVI1 and EVI1-Ξ”D where as no amplification was observed in vector transfected cells or EVI1-Ξ”A transfected cells. Marker and the input control are as shown.</p
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