105 research outputs found

    Adsorption of Algerian Asphaltenes onto Synthesized Maghemite Iron Oxide Nanoparticles

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    In this study, the adsorption of Algerian asphaltene sample extracted from Hassi Messaoud oil field is conducted for the first time. The adsorption process was performed using novel synthesized iron oxide nanoparticles (γ-Fe2O3). γ-Fe2O3 Nanoparticles were in-house synthesized and characterized by an array of techniques using, Brunauer-Emmett-Teller (BET), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The results showed that the synthesized nanoparticles have an average crystalline domain size around 10 nm and a specific surface area of 120 m2/g. The adsorption process of the Algerian asphaltenes took place in a batch mode by dissolving the asphaltenes in toluene at 25°C. Different initial concentrations of asphaltene solutions were used in this study, namely 100, 500, and 1000 ppm. During this adsorption, both isotherm and kinetic studies were investigated. The results showed that the synthesized iron oxide nanoparticles are promising nano-adsorbents that have a high affinity to remove the asphaltenes and the equilibrium was recorded after 15 min. The Solid-Liquid-Equilibrium (SLE) model was used to correlate the adsorption experimental data

    HIV-1 subtype A gag variability and epitope evolution

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    Objective: The aim of this study was to examine the course of time-dependent evolution of HIV-1 subtype A on a global level, especially with respect to the dynamics of immunogenic HIV gag epitopes.Methods: We used a total of 1,893 HIV-1 subtype A gag sequences representing a timeline from 1985 through 2010, and 19 different countries in Africa, Europe and Asia. The phylogenetic relationship of subtype A gag and its epidemic dynamics was analysed through a Maximum Likelihood tree and Bayesian Skyline plot, genomic variability was measured in terms of G → A substitutions and Shannon entropy, and the time-dependent evolution of HIV subtype A gag epitopes was examined. Finally, to confirm observations on globally reported HIV subtype A sequences, we analysed the gag epitope data from our Kenyan, Pakistani, and Afghan cohorts, where both cohort-specific gene epitope variability and HLA restriction profiles of gag epitopes were examined. Results: The most recent common ancestor of the HIV subtype A epidemic was estimated to be 1956 ± 1. A period of exponential growth began about 1980 and lasted for approximately 7 years, stabilized for 15 years, declined for 2-3 years, then stabilized again from about 2004. During the course of evolution, a gradual increase in genomic variability was observed that peaked in 2005-2010. We observed that the number of point mutations and novel epitopes in gag also peaked concurrently during 2005-2010. Conclusion: It appears that as the HIV subtype A epidemic spread globally, changing population immunogenetic pressures may have played a role in steering immune-evolution of this subtype in new directions. This trend is apparent in the genomic variability and epitope diversity of HIV-1 subtype A gag sequences

    Posterior Mediastinal Chondrosarcoma- A rare entity

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    Introduction:Chondrosarcoma is a well defined tumor of soft tissue with calcification. Extraskeletal myxoid chondrosarcoma is an unusual sarcoma of soft tissue adding only 3% to all soft tissue tumors. Majority of mediastinal foci originates from variety of tissues, the reason being their diverse embryological and anatomical approximations. Chondrosarcomas are more common in males with 2:1 male to female ratio. The exact pathology of these tumors is unclear; however recent data ensures that these tumors have multidirectional delineation. Classical histopathological features of chondrosarcoma include S-100 positivity, EMA positivity. These features of Immunohistochemical favor extra skeletal myxoid chondrosarcoma.Case Report:Recent data signifies that the tumor is known for its rare occurrence, here we have reported a unique case of 40 years old male visited Abbasi Shaheed Hospital for pre employment checkup without any symptoms. All the tests were negative except Chest X-ray PA view which revealed dense mass on lower lobe of lung. For further evaluation, CT scan of chest with contrast was ordered and eventually the mass was resected surgically. On the basis of macro and microscopic findings, histopathological tests and immunohistochemical stains, the mass was found to be chondrosarcoma with myxoid origin. This tumor has to be distinguishing among the list of different diseases like hamartoma, hydatid cyst, and neuroendocrine tumors for the differential diagnosis of the case.Conclusion: Our paper reports an extraskeletal mesenchymal chondrosarcoma originating in the posterior mediastinum with a rare presentation.Â

    Variation of Peak Expiratory Flow Rate with Body Mass Index in Medical Students of Karachi, Pakistan

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    OBJECTIVE: The primary aim of our study was to assess the variation of PEFR with BMI in normal medical students of Karachi, PakistanDESIGN: Cross-sectional studySetting: Medical students of Karachi Medical and Dental CollegeParticipants: 138 non-smoker healthy medical students composed of 111 females and 27 males. VARIABLE PARAMETERS: They include mean age, body height and body weight and PEFR. They were marked separately for each genderRESULTS: The mean BMI in females was found out to be 18.54±2.10 corresponding with that of mean PEFR value 431.62±56.62 whereas in males the mean BMI was 25.07±2.96 corresponding with that of mean PEFR value 533.70±23.22. Also there is a statistically significant variation in PEFR with an increase in BMI.CONCLUSION: The study concludes that PEFR is affected positively by variation in BMI. Also young males have more BMI and PEFR values than their young female counterparts. A large sample size with accurate peak flow meter is required along with ethnic consideration of the study population for better and accurate result

    Phylogenetic and drug-resistance analysis of HIV-1 sequences from an extensive paediatric HIV-1 outbreak in Larkana, Pakistan

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    Introduction: In April 2019, an HIV-1 outbreak among children occurred in Larkana, Pakistan, affecting more than a thousand children. It was assumed that the outbreak originated from a single source, namely a doctor at a private health facility. In this study, we performed subtype distribution, phylogenetic and drug-resistance analysis of HIV-1 sequences from 2019 outbreak in Larkana, Pakistan.Methods: A total of 401 blood samples were collected between April-June 2019, from children infected with HIV-1 aged 0-15 years recruited into a case-control study to investigate the risk factors for HIV-1 transmission. Partial HIV-1 pol sequences were generated from 344 blood plasma samples to determine HIV-1 subtype and drug resistance mutations (DRM). Maximum-likelihood phylogenetics based on outbreak and reference sequences was used to identify transmission clusters and assess the relationship between outbreak and key population sequences between and within the determined clusters. Bayesian analysis was employed to identify the time to the most recent common recent ancestor (tMRCA) of the main Pakistani clusters.Results: The HIV-1 circulating recombinant form (CRF) 02_AG and subtype A1 were most common among the outbreak sequences. Of the treatment-naïve participants, the two most common mutations were RT: E138A (8%) and RT: K219Q (8%). Four supported clusters within the outbreak were identified, and the median tMRCAs of the Larkana outbreak sequences were estimated to 2016 for both the CRF02_AG and the subtype A1 clusters. Furthermore, outbreak sequences exhibited no phylogenetic mixing with sequences from other high-risk groups of Pakistan.Conclusion: The presence of multiple clusters indicated a multi-source outbreak, rather than a single source outbreak from a single health practitioner as previously suggested. The multiple introductions were likely a consequence of ongoing transmission within the high-risk groups of Larkana, and it is possible that the so-called Larkana strain was introduced into the general population through poor infection prevention control practices in healthcare settings. The study highlights the need to scale up HIV-1 prevention programmes among key population groups and improving infection prevention control in Pakistan

    Exploring and Expanding the Fatty-Acid-Binding Protein Superfamily in Fasciola Species

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    The liver flukes Fasciola hepatica and F. gigantica infect livestock worldwide and threaten food security with climate change and problematic control measures spreading disease. Fascioliasis is also a food borne disease with up to 17 million humans infected. In the absence of vaccines, treatment depends on Triclabendazole (TCBZ) and over-use has led to widespread resistance, compromising future TCBZ control. Reductionist biology from many laboratories has predicted new therapeutic targets. To this end, the fatty acid binding protein (FABP) superfamily have proposed multi-functional roles, including functions intersecting vaccine and drug therapy, such as immune modulation and anthelmintic sequestration. Research is hindered by a lack of understanding of the full FABP superfamily complement. Although discovery studies predicted FABPs as promising vaccine candidates, it is unclear if uncharacterised FABPs are more relevant for vaccine formulations. We have coupled genome, transcriptome and EST data mining with proteomics and phylogenetics, to reveal a liver fluke FABP superfamily of 7 clades: previously identified clades I-III and newly identified clades IV-VII. All new clade FABPs were analysed using bioinformatics and cloned from both liver flukes. The extended FABP dataset will provide new study tools to research the role of FABPs in parasite biology and as therapy targets

    DETECTION AND CHARACTERIZATION OF LATENCY STAGE OF EBV AND HISTOPATHOLOGICAL ANALYSIS OF PROSTATIC ADENOCARCINOMA TISSUES

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    The pathophysiology of prostate cancer involves both genetic and acquired factors, including pathogens, such as viruses. A limited number of studies have shown the presence of Epstein-Barr virus (EBV) in prostate cancer tissues. However, there is a dearth of data exploring EBV latency profile in prostate cancer, and the relationship of EBV with histopathological features of prostate cancer. In this study, prostate cancer and benign prostatic hyperplasia (BPH) samples were screened for the presence of EBV, followed by the characterization of the EBV latency profile and analysis of histopathological parameters in EBV-positive and EBV-negative groups. A conventional PCR strategy was employed using virus-specific primers to screen EBV in 99 formalin-fixed paraffin-embedded (FFPE) prostate cancer and 33 BPH samples received for histopathological analysis during the years 2019–2020. Subsequently, cDNA samples were used in a qPCR array to analyze the expression of EBV latency-associated genes to map the latency profile EBV maintains in the samples. Finally, statistical analyses were performed to determine the correlation between EBV and several histopathological features of the samples. EBV was detected in 39% of prostate cancer and 24% of BPH samples. The histopathological analysis of prostate cancer samples identified all samples as prostatic adenocarcinoma of acinar type, while statistical analyses revealed EBV-positive samples to exhibit significantly higher (p < 0.05) Gleason major and total Gleason scores as compared to EBV-negative samples. In the EBV-positive samples, variable expression patterns of latency-associated genes were observed, where most of the samples exhibited EBV latency II/III-like profiles in prostate cancer, while latency-II-like profiles in BPH samples. This study suggests a high prevalence of EBV in prostate samples, where EBV exhibited latency II/III-like profiles. Furthermore, EBV-positive samples exhibited a higher Gleason score suggesting a possible link between EBV and the onset/progression of prostate cancers. However, future functional studies are required to understand the role of the EBV gene expression profile in the onset/progression of prostate cancer

    RNAi dynamics in juvenile Fasciola spp. liver flukes reveals the persistence of gene silencing in vitro

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    Fasciola spp. liver fluke cause pernicious disease in humans and animals. Whilst current control is unsustainable due to anthelmintic resistance, gene silencing (RNA interference, RNAi) has the potential to contribute to functional validation of new therapeutic targets. The susceptibility of juvenile Fasciola hepatica to double stranded (ds)RNA-induced RNAi has been reported. To exploit this we probe RNAi dynamics, penetrance and persistence with the aim of building a robust platform for reverse genetics in liver fluke. We describe development of standardised RNAi protocols for a commercially-available liver fluke strain (the US Pacific North West Wild Strain), validated via robust transcriptional silencing of seven virulence genes, with in-depth experimental optimisation of three: cathepsin L (FheCatL) and B (FheCatB) cysteine proteases, and a σ-class glutathione transferase (FheσGST).Robust transcriptional silencing of targets in both F. hepatica and Fasciola gigantica juveniles is achievable following exposure to long (200-320 nt) dsRNAs or 27 nt short interfering (si)RNAs. Although juveniles are highly RNAi-susceptible, they display slower transcript and protein knockdown dynamics than those reported previously. Knockdown was detectable following as little as 4h exposure to trigger (target-dependent) and in all cases silencing persisted for ≥25 days following long dsRNA exposure. Combinatorial silencing of three targets by mixing multiple long dsRNAs was similarly efficient. Despite profound transcriptional suppression, we found a significant time-lag before the occurrence of protein suppression; FheσGST and FheCatL protein suppression were only detectable after 9 and 21 days, respectively.In spite of marked variation in knockdown dynamics, we find that a transient exposure to long dsRNA or siRNA triggers robust RNAi penetrance and persistence in liver fluke NEJs supporting the development of multiple-throughput phenotypic screens for control target validation. RNAi persistence in fluke encourages in vivo studies on gene function using worms exposed to RNAi-triggers prior to infection

    In silico characterisation of the complete Ly6 protein family in Fasciola gigantica supported through transcriptomics of the newly-excysted juveniles

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    Fasciola gigantica is one of the aetiological trematodes associated with fascioliasis, which heavily impacts food-production systems and human and animal welfare on a global scale. In the absence of a vaccine, fascioliasis control and treatment is restricted to pasture management, such as clean grazing, and a limited array of chemotherapies, to which signs of resistance are beginning to appear. Research into novel control strategies is therefore urgently required and the advent of ‘omics technologies presents considerable opportunity for novel drug and vaccine target discovery. Here, interrogation of the first available F. gigantica newly excysted juvenile (NEJ) transcriptome revealed several protein families of current interest to parasitic flatworm vaccine research, including orthologues of mammalian complement regulator CD59 of the Ly6 family. Ly6 proteins have previously been identified on the tegument of Schistosoma mansoni and induced protective immunity in vaccination trials. Incorporating the recently available F. gigantica genome, the current work revealed 20 novel Ly6 family members in F. gigantica and, in parallel, significantly extended the F. hepatica complement from 3 to 18 members. Phylogenetic analysis revealed several distinct clades within the family, some of which are unique to Fasciola spp. trematodes. Analysis of available proteomic databases also revealed three of the newly discovered FhLy6s were present in extracellular vesicles, which have previously been prioritised in studying the host-parasite interface. The presentation of this new transcriptomic resource, in addition to the Ly6 family proteins here identified, represents a wealth of opportunity for future vaccine research

    HIV infection predominantly affecting children in Sindh, Pakistan, 2019: a cross-sectional study of an outbreak.

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    BACKGROUND: In April 2019, an HIV screening camp for all ages was established in response to a report of an unusually large number of paediatric HIV diagnoses in Larkana, Pakistan. We aimed to understand the clinical profile of the children who registered for HIV care. METHODS: In this cross-sectional study, we review the outbreak response from the government, academia, and UN agencies in Larkana, Sindh, Pakistan. We report age-stratified and sex-stratified HIV prevalence estimated among individuals screened. For children who registered for HIV care, clinical history of previous injections and blood transfusions, HIV disease stage, hepatitis B and hepatitis C status, and CD4 count was abstracted from clinical records from Sindh AIDS Control Program HIV Clinic (Shaikh Zayed Childrens Hospital, Larkana, Pakistan) and analysed using percentages, χ2 tests, and weight-for-age Z scores. We also analysed data for parents who were tested for HIV. FINDINGS: Between April 24, and July 15, 2019, 31 239 individuals underwent HIV testing, of whom 930 (3%) tested positive for HIV. Of these, 763 (82%) were younger than 16 years and 604 (79%) of these were aged 5 years and below. Estimated HIV prevalence was 3% overall; 7% (283 of 3803) in children aged 0-2 years, 6% (321 of 5412) in children aged 3-5 years, and 1% (148 of 11 251) in adults aged 16-49 years. Of the 591 children who registered for HIV care, 478 (81%) were 5 years or younger, 379 (64%) were boys, and 315 (53%) of 590 had a weight-for-age Z score of -3·2. Prevalence of hepatitis B surface antigen was 8% (48 of 574) and hepatitis C antibody positivity was 3% (15 of 574). Of children whose mothers tested for HIV, only 39 (11%) of 371 had HIV-positive mothers. Most children (404 [89%] of 453) reported multiple previous injections and 40 (9%) of 453 reported blood transfusions. INTERPRETATION: This HIV outbreak is unprecedented among children in Pakistan: a 54% increase in paediatric HIV diagnoses over the past 13 years. The outbreak was heavily skewed towards young children younger than 5 years, with a predominance of boys. Epidemiological and molecular studies are needed to understand the full extent of the outbreak and its drivers to guide HIV control strategies. FUNDING: None
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