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1.
Vet Sci ; 11(6)2024 Jun 19.
Article de Anglais | MEDLINE | ID: mdl-38922027

RÉSUMÉ

Peste des petits ruminants (PPR) is an extremely transmissible viral disease caused by the PPR virus that impacts domestic small ruminants, namely sheep and goats. This study aimed to employ a methodical approach to evaluate the regional occurrence of PPR in small ruminants in Pakistan and the contributing factors that influence its prevalence. A thorough search was performed in various databases to identify published research articles between January 2004 and August 2023 on PPR in small ruminants in Pakistan. Articles were chosen based on specific inclusion and exclusion criteria. A total of 25 articles were selected from 1275 studies gathered from different databases. The overall pooled prevalence in Pakistan was calculated to be 51% (95% CI: 42-60), with heterogeneity I2 = 100%, τ2 = 0.0495, and p = 0. The data were summarized based on the division into five regions: Punjab, Baluchistan, KPK, Sindh, and GB and AJK. Among these, the pooled prevalence of PPR in Sindh was 61% (95% CI: 46-75), I2 = 100%, τ2 = 0.0485, and p = 0, while in KPK, it was 44% (95% CI: 26-63), I2 = 99%, τ2 = 0.0506, and p < 0.01. However, the prevalence of PPR in Baluchistan and Punjab was almost the same. Raising awareness, proper surveillance, and application of appropriate quarantine measures interprovincially and across borders must be maintained to contain the disease.

2.
Strahlenther Onkol ; 2024 Jun 25.
Article de Anglais | MEDLINE | ID: mdl-38918259

RÉSUMÉ

INTRODUCTION: Risk factors for developing osteoradionecrosis (ORN) are well known, but less is known about factors influencing the interval between radiotherapy and the onset of ORN. Also, it is unknown whether there is any specific period post-radiotherapy with a reduced probability of ORN when irradiated teeth require extraction. PURPOSE: The primary aim of this study was to identify factors influencing the interval in developing ORN in the following subgroups of patients: (1) patients who spontaneously developed ORN, (2) surgical-intervention-related ORN with a particular focus on patients after mandibulectomy. The secondary aim was to attempt to identify a possible time for safer dental intervention after primary treatment. MATERIALS AND METHODS: The authors retrospectively analysed 1608 head and neck cancer (HNC) patients treated in a single centre. Time intervals were measured from the end of radiotherapy to the development of ORN and further analysed in the subgroups listed above. RESULTS: In all, 141 patients (8.8%) developed intra-oral ORN. Median time from radiotherapy to ORN development in the whole cohort was 9 months. Median interval for spontaneous ORN was 8 months, 6.5 months for intervention-related ORN, and 15 months for patients post-mandibulectomy. In patients who required dental extraction preradiotherapy, median interval of ORN onset was 5 months. CONCLUSION: In our study, a slightly higher proportion of patients with intervention developed ORN earlier in comparison with spontaneous ORN. The period from 12-18 months after radiotherapy was identified as having the highest probability of developing ORN in patients after mandibulectomy. A time for safer dental intervention after primary treatment was not identified.

4.
bioRxiv ; 2023 Dec 09.
Article de Anglais | MEDLINE | ID: mdl-38105993

RÉSUMÉ

Japanese Encephalitis Virus (JEV) NS2B-NS3 is a protein complex composed of NS3 proteases and a NS2B cofactor. The N-terminal protease domain (180 residues) of NS3 (NS3(pro)) interacts directly with a central 40-amino acid hydrophilic domain of NS2B (NS2B(H)) to form an active serine protease. In this study, the recombinant NS2B(H)-NS3(pro) proteases were prepared in E. coli and used to compare the enzymatic activity between genotype I (GI) and III (GIII) NS2B-NS3 proteases. The GI NS2B(H)-NS3(pro) was able to cleave the sites at internal C, NS2A/NS2B, NS2B/NS3 and NS3/NS4A junctions that were identical to the sites proteolytically processed by GIII NS2B(H)-NS3(pro). Analysis of the enzymatic activity of recombinant NS2B(H)-NS3(pro) proteases using a model of fluorogenic peptide substrate revealed that the proteolytical processing activity of GIII NS2B(H)-NS3(pro) was significantly higher than that of GI NS2B(H)-NS3(pro). There were eight amino acid variations between GI and GIII NS2B(H)-NS3(pro), which may be responsible for the difference in enzymatic activities between GI and GIII proteases. Therefore, recombinant mutants were generated by exchanging NS2B(H) and NS3(pro) domains between GI and GIII NS2B(H)-NS3(pro) and subjected to protease activity analysis. Substitution of NS2B(H) significantly altered the protease activities, as compared to the parental NS2B(H)-NS3(pro), suggesting that NS2B(H) played an essential role in regulation of NS3(pro) protease activity. To further identify the amino acids responsible for the difference in protease activities, multiple substitution mutants including the individual and combined mutations at the variant residue 55 and 65 of NS2B(H) were generated and subjected to protease activity analysis. Replacement of NS2B-55 and NS2B-65 of GI to GIII significantly increased the enzymatic activity of GI NS2B(H)-NS3(pro) protease, whereas mutation of NS2B-55 and NS2B-65 of GIII to GI remarkably reduced the enzymatic activity of GIII NS2B(H)-NS3(pro) protease. Overall, these data demonstrated that NS2B-55 and NS2B-65 variations in hydrophilic domain of NS2B co-contributed to the difference in NS2B(H)-NS3(pro) protease activities between GI and GIII. These observations gain an insight into the role of NS2B in regulation of NS3 protease activities, which is useful for understanding the replication of JEV GI and GIII viruses.

5.
J Virol ; 97(6): e0038223, 2023 06 29.
Article de Anglais | MEDLINE | ID: mdl-37289075

RÉSUMÉ

Palmitoylation of viral proteins is crucial for host-virus interactions. In this study, we examined the palmitoylation of Japanese encephalitis virus (JEV) nonstructural protein 2A (NS2A) and observed that NS2A was palmitoylated at the C221 residue of NS2A. Blocking NS2A palmitoylation by introducing a cysteine-to-serine mutation at C221 (NS2A/C221S) impaired JEV replication in vitro and attenuated the virulence of JEV in mice. NS2A/C221S mutation had no effect on NS2A oligomerization and membrane-associated activities, but reduced protein stability and accelerated its degradation through the ubiquitin-proteasome pathway. These observations suggest that NS2A palmitoylation at C221 played a role in its protein stability, thereby contributing to JEV replication efficiency and virulence. Interestingly, the C221 residue undergoing palmitoylation was located at the C-terminal tail (amino acids 195 to 227) and is removed from the full-length NS2A following an internal cleavage processed by viral and/or host proteases during JEV infection. IMPORTANCE An internal cleavage site is present at the C terminus of JEV NS2A. Following occurrence of the internal cleavage, the C-terminal tail (amino acids 195 to 227) is removed from the full-length NS2A. Therefore, it was interesting to discover whether the C-terminal tail contributed to JEV infection. During analysis of viral palmitoylated protein, we observed that NS2A was palmitoylated at the C221 residue located at the C-terminal tail. Blocking NS2A palmitoylation by introducing a cysteine-to-serine mutation at C221 (NS2A/C221S) impaired JEV replication in vitro and attenuated JEV virulence in mice, suggesting that NS2A palmitoylation at C221 contributed to JEV replication and virulence. Based on these findings, we could infer that the C-terminal tail might play a role in the maintenance of JEV replication efficiency and virulence despite its removal from the full-length NS2A at a certain stage of JEV infection.


Sujet(s)
Virus de l'encéphalite japonaise (espèce) , Encéphalite japonaise , Protéines virales non structurales , Réplication virale , Animaux , Souris , Lignée cellulaire , Cystéine/métabolisme , Virus de l'encéphalite japonaise (espèce)/physiologie , Lipoylation , Sérine/métabolisme , Protéines virales non structurales/métabolisme , Virulence
6.
Viruses ; 15(6)2023 06 02.
Article de Anglais | MEDLINE | ID: mdl-37376612

RÉSUMÉ

Japanese encephalitis virus (JEV) causes acute viral encephalitis in humans and reproductive disorders in pigs. JEV emerged during the 1870s in Japan, and since that time, JEV has been transmitted exclusively throughout Asia, according to known reporting and sequencing records. A recent JEV outbreak occurred in Australia, affecting commercial piggeries across different temperate southern Australian states, and causing confirmed infections in humans. A total of 47 human cases and 7 deaths were reported. The recent evolving situation of JEV needs to be reported due to its continuous circulation in endemic regions and spread to non-endemics areas. Here, we reconstructed the phylogeny and population dynamics of JEV using recent JEV isolates for the future perception of disease spread. Phylogenetic analysis shows the most recent common ancestor occurred about 2993 years ago (YA) (95% Highest posterior density (HPD), 2433 to 3569). Our results of the Bayesian skyline plot (BSP) demonstrates that JEV demography lacks fluctuations for the last two decades, but it shows that JEV genetic diversity has increased during the last ten years. This indicates the potential JEV replication in the reservoir host, which is helping it to maintain its genetic diversity and to continue its dispersal into non-endemic areas. The continuous spread in Asia and recent detection from Australia further support these findings. Therefore, an enhanced surveillance system is needed along with precautionary measures such as regular vaccination and mosquito control to avoid future JEV outbreaks.


Sujet(s)
Virus de l'encéphalite japonaise (espèce) , Encéphalite japonaise , Humains , Animaux , Suidae , Virus de l'encéphalite japonaise (espèce)/génétique , Encéphalite japonaise/épidémiologie , Phylogenèse , Théorème de Bayes , Australie/épidémiologie , Génotype
7.
Sensors (Basel) ; 22(22)2022 Nov 09.
Article de Anglais | MEDLINE | ID: mdl-36433232

RÉSUMÉ

With a large number of Local Binary Patterns (LBP) variants being currently used today, the significant and importance of visual descriptors in computer vision applications are prominent. This paper presents a novel visual descriptor, i.e., SIM-LBP. It employs a new matrix technique called the Symmetric Inline Matrix generator method, which acts as a new variant of LBP. The key feature that separates our variant from existing counterparts is that our variant is very efficient in extracting facial expression features like eyes, eye brows, nose and mouth in a wide range of lighting conditions. For testing our model, we applied SIM-LBP on the JAFFE dataset to convert all the images to its corresponding SIM-LBP transformed variant. These transformed images are then used to train a Convolution Neural Network (CNN) based deep learning model for facial expressions recognition (FER). Several performance evaluation metrics, i.e., recognition accuracy rate, precision, recall, and F1-score, were used to test mode efficiency in comparison with those using the traditional LBP descriptor and other LBP variants. Our model outperformed in all four matrices with the proposed SIM-LBP transformation on the input images against those of baseline methods. In comparison analysis with the other state-of-the-art methods, it shows the usefulness of the proposed SIM-LBP model. Our proposed SIM-LBP variant transformation can also be applied on facial images to identify a person's mental states and predict mood variations.


Sujet(s)
Expression faciale , Reconnaissance faciale , Humains , , Face , Émotions
8.
Virology ; 568: 77-85, 2022 03.
Article de Anglais | MEDLINE | ID: mdl-35149346

RÉSUMÉ

Flaviviruses are a group of enveloped viruses that enter the host cells through receptor-mediated endocytosis. The entry of flaviviruses into the cells is a multi-step process which involves several host factors that trigger the uptake of the virus. The initial step in the virus life cycle is the interactions between viral envelope proteins and the specific receptors on the surface of host cell. To date, several receptors have been identified such as glycosaminoglycans, tight junction proteins, laminin receptor and phosphatidylserine receptors. Moreover, the viruses may utilize integrins and C-type lectin receptors on the surface of host cells as the initial attachment factors. This mini-review will focus on recent progresses in the understanding of virus attachment, internalization, and membrane fusion with specific emphasis on the cellular receptors.


Sujet(s)
Infections à flavivirus/métabolisme , Infections à flavivirus/virologie , Flavivirus/physiologie , Interactions hôte-pathogène , Récepteurs viraux/métabolisme , Pénétration virale , Animaux , Prédisposition aux maladies , Endocytose , Humains , Liaison aux protéines , Multimérisation de protéines , Récepteurs viraux/composition chimique , Relation structure-activité , Attachement viral , Réplication virale
9.
Vaccines (Basel) ; 9(9)2021 Sep 02.
Article de Anglais | MEDLINE | ID: mdl-34579217

RÉSUMÉ

Virus-like particles (VLPs) are non-replicative vectors for the delivery of heterologous epitopes and are considered one of the most potent inducers of cellular and humoral immune responses in mice and guinea pigs. In the present study, VLP-JEVe was constructed by the insertion of six Japanese encephalitis virus (JEV) envelope protein epitopes into different surface loop regions of PPV VP2 by the substitution of specific amino acid sequences without altering the assembly of the virus; subsequently, the protective efficacy of this VLP-JEVe was evaluated against JEV challenge in mice and guinea pigs. Mice immunized with the VLP-JEVe antigen developed high titers of neutralizing antibodies and 100% protection against lethal JEV challenge. The neutralizing and hemagglutination inhibition (HI) antibody responses were also induced in guinea pigs vaccinated with VLP-JEVe. In addition, immunization with VLP-JEVe in mice induced effective neutralizing antibodies and protective immunity against PPV (porcine parvovirus) challenge in guinea pigs. These studies suggest that VLP-JEVe produced as described here could be a potential candidate for vaccine development.

10.
J Hazard Mater ; 416: 125851, 2021 08 15.
Article de Anglais | MEDLINE | ID: mdl-34492802

RÉSUMÉ

This study examines point and non-point sources of air pollution and particulate matter and their associated socioeconomic and health impacts in South Asian countries, primarily India, China, and Pakistan. The legislative frameworks, policy gaps, and targeted solutions are also scrutinized. The major cities in these countries have surpassed the permissible limits defined by WHO for sulfur dioxide, carbon monoxide, particulate matter, and nitrogen dioxide. As a result, they are facing widespread health problems, disabilities, and causalities at extreme events. Populations in these countries are comparatively more prone to air pollution effects because they spend more time in the open air, increasing their likelihood of exposure to air pollutants. The elevated level of air pollutants and their long-term exposure increases the susceptibility to several chronic/acute diseases, i.e., obstructive pulmonary diseases, acute respiratory distress, chronic bronchitis, and emphysema. More in-depth spatial-temporal air pollution monitoring studies in China, India, and Pakistan are recommended. The study findings suggest that policymakers at the local, national, and regional levels should devise targeted policies by considering all the relevant parameters, including the country's economic status, local meteorological conditions, industrial interests, public lifestyle, and national literacy rate. This approach will also help design and implement more efficient policies which are less likely to fail when brought into practice.


Sujet(s)
Polluants atmosphériques , Pollution de l'air , Polluants atmosphériques/analyse , Polluants atmosphériques/toxicité , Pollution de l'air/effets indésirables , Pollution de l'air/analyse , Chine , Inde , Dioxyde d'azote , Pakistan , Matière particulaire/analyse , Matière particulaire/toxicité , Dioxyde de soufre/analyse , Dioxyde de soufre/toxicité
11.
Cureus ; 13(5): e14789, 2021 May 01.
Article de Anglais | MEDLINE | ID: mdl-34094751

RÉSUMÉ

Visceral artery aneurysms, which could be either true or pseudo, are abnormal focal dilations of vessels supplying the abdominal organs. True aneurysms, by definition, suggest dilation of the vessel in response to increased blood flow, ultimately causing a blood-filled sac to form. Pseudoaneurysm, however, is the pooling of blood in surrounding tissues secondary to trauma or rupture. A 43-year-old woman G9 P9, known hypertensive was admitted electively for investigation of melena, hematemesis, hematochezia for one week along with weight loss and epigastric pain. Laboratory studies showed mild anemia with a hemoglobin level of 9.6 g/dL, hematocrit 29.5%, mean corpuscular hemoglobin (MCH) 26.7, upon which she was transfused two pints of blood and commenced at Injectable Vitamin K, injectable transamine, and infusion omeprazole. Two days later her levels improved to HB 12.4 g/dL, hematocrit 37.5%, MCH 26.7 pg, RBC 4.64 × 10*12/L. while being on treatment, a computed tomography (CT) mesenteric angiography was also conducted that showed multiple splanchnic pseudoaneurysms involving celiac axis trifurcation, gastroduodenal artery, superior/inferior pancreaticoduodenal artery, and jejunoileal branch of the superior mesenteric artery, and a large partially thrombosed pseudoaneurysm arising from superior pancreaticoduodenal branch causing significant mass effect on the second part of duodenum. On the basis of such findings, it was advised to perform coiling and embolization of the corresponding arteries. Multiple other small aneurysms with secondary arteriovenous malformations (AVM) were also seen. The whole circuit of flow retrograde and antegrade along with the aneurysm sac was blocked with multiple coils of variable sizes. An angiogram was repeated that revealed a good outcome. Pseudoaneurysms of the visceral arteries are very rare and affect mainly the splenic artery. The rarest of which is gastroduodenal artery (1.5%), pancreaticoduodenal artery (2%), and coeliac truck (4%). Therefore, this can be an incidental finding. The diagnosis is usually made with an angiography combined with clinical presentation. Variable treatment options are available depending on the patient's fitness and hemodynamic stability. The endovascular approach, however, is mostly used in such cases.

12.
Genes (Basel) ; 12(4)2021 03 29.
Article de Anglais | MEDLINE | ID: mdl-33805275

RÉSUMÉ

Newcastle disease virus (NDV) causes a highly contagious and devastating disease in poultry. ND causes heavy economic losses to the global poultry industry by decreasing the growth rate, decrease in egg production high morbidity and mortality. Although significant advances have been made in the vaccine development, outbreaks are reported in vaccinated birds. In this study, we report the damage caused by NDV infection in the pancreatic tissues of vaccinated and specific-pathogen-free chickens. The histopathological examination of the pancreas showed severe damage in the form of partial depletion of zymogen granules, acinar cell vacuolization, necrosis, apoptosis, congestion in the large and small vessels, sloughing of epithelial cells of the pancreatic duct, and mild perivascular edema. Increased plasma levels of corticosterone and somatostatin were observed in NDV-infected chicken at three- and five- days post infection (DPI). A slight decrease in the plasma concentrations of insulin was noticed at 5 DPI. Significant changes were not observed in the plasma levels of glucagon. Furthermore, NDV infection decreased the activity and mRNA expression of amylase, lipase, and trypsin from the pancreas. Taken together, our findings highlight that NDV induces extensive tissue damage in the pancreas, decreases the activity and expression of pancreatic enzymes, and increases plasma corticosterone and somatostatin. These findings provide new insights that a defective pancreas may be one of the reasons for decreased growth performance after NDV infection in chickens.


Sujet(s)
Ilots pancréatiques/anatomopathologie , Maladie de Newcastle/complications , Virus de la maladie de Newcastle/isolement et purification , Pancréas exocrine/anatomopathologie , Pancréatite/médecine vétérinaire , Maladies de la volaille/anatomopathologie , Animaux , Poulets , Ilots pancréatiques/métabolisme , Ilots pancréatiques/virologie , Maladie de Newcastle/métabolisme , Maladie de Newcastle/virologie , Pancréas exocrine/métabolisme , Pancréas exocrine/virologie , Pancréatite/anatomopathologie , Pancréatite/virologie , Maladies de la volaille/épidémiologie , Maladies de la volaille/virologie
13.
Pathogens ; 10(2)2021 Jan 21.
Article de Anglais | MEDLINE | ID: mdl-33494395

RÉSUMÉ

Understanding the proteolytic processing of polyprotein mediated by NS2B-NS3 protease contributes to the exploration of the mechanisms underlying infection of Japanese encephalitis virus (JEV), a zoonotic flavivirus. In this study, eukaryotic and prokaryotic cell models were employed to identify the cleavage sites mediated by viral NS2B-NS3 protease in JEV polyprotein. Artificial green fluorescent protein (GFP) substrates that contained the predicted cleavage site sequences of JEV polyprotein were expressed in swine testicle (ST) cells in the presence and absence of JEV infection, or co-expressed in E. coli with the recombinant NS2B-NS3 protease that was generated by fusing the N-terminal protease domain of NS3 to the central hydrophilic domain of NS2B. The cleavage of GFP substrates was examined by western blot. Among twelve artificial GFP substrates containing the cleavage site sequences predictively processed by host cell and/or NS2B-NS3 proteases, all sites were found to be cleaved by host cell proteases with different efficiencies. The sites at internal C, NS2A/NS2B, NS2B/NS3 and NS3/NS4A junctions, but not the sites at internal NS3, internal NS4A and NS4B/NS5 junctions were identified to be cleaved by JEV NS2B-NS3 protease. These data provide insight into the proteolytic processing of polyprotein, which is useful for understanding JEV replication and pathogenesis.

14.
Viruses ; 14(1)2021 12 28.
Article de Anglais | MEDLINE | ID: mdl-35062249

RÉSUMÉ

Flaviviruses are known to cause a variety of diseases in humans in different parts of the world. There are very limited numbers of antivirals to combat flavivirus infection, and therefore new drug targets must be explored. The flavivirus NS2B-NS3 proteases are responsible for the cleavage of the flavivirus polyprotein, which is necessary for productive viral infection and for causing clinical infections; therefore, they are a promising drug target for devising novel drugs against different flaviviruses. This review highlights the structural details of the NS2B-NS3 proteases of different flaviviruses, and also describes potential antiviral drugs that can interfere with the viral protease activity, as determined by various studies. Moreover, optimized in vitro reaction conditions for studying the NS2B-NS3 proteases of different flaviviruses may vary and have been incorporated in this review. The increasing availability of the in silico and crystallographic/structural details of flavivirus NS2B-NS3 proteases in free and drug-bound states can pave the path for the development of promising antiflavivirus drugs to be used in clinics. However, there is a paucity of information available on using animal cells and models for studying flavivirus NS2B-NS3 proteases, as well as on the testing of the antiviral drug efficacy against NS2B-NS3 proteases. Therefore, on the basis of recent studies, an effort has also been made to propose potential cellular and animal models for the study of flavivirus NS2B-NS3 proteases for the purposes of exploring flavivirus pathogenesis and for testing the efficacy of possible drugs targets, in vitro and in vivo.


Sujet(s)
Antiviraux/pharmacologie , Découverte de médicament , Infections à flavivirus/virologie , Flavivirus/enzymologie , Peptide hydrolases/métabolisme , RNA helicases/métabolisme , Serine endopeptidases/métabolisme , Protéines virales non structurales/métabolisme , Animaux , Virus de la dengue , Diminution progressive de la dose du médicament , Virus de l'encéphalite japonaise (espèce) , Flavivirus/génétique , Humains , Peptide hydrolases/génétique , Polyprotéines , RNA helicases/génétique , Serine endopeptidases/génétique , Protéines virales non structurales/génétique , Protéines du complexe des réplicases virales , Virus du Nil occidental , Virus de la fièvre jaune , Virus Zika
15.
J Hazard Mater ; 402: 123943, 2021 01 15.
Article de Anglais | MEDLINE | ID: mdl-33254830

RÉSUMÉ

This study, for the first time, aims to evaluate the situation of air quality in Pakistan critically; through a detailed assessment of sources, policies, and key challenges to identify the plausible way forward. Air pollution and particulate matter have merged as a global challenge in recent years because of its growing health and socio-economic risks. The intensity and impacts of these risks have become more pronounced, especially in developing countries like Pakistan that lack adequate warning, protection, and management systems. Various epidemiological studies have linked poor air quality with different health disorders and increasing death rates. In Pakistan, mortality rates as a result of exposure to increased levels of air pollutants, especially particulate matter, are alarming. According to the World Bank's estimates, Pakistan's annual burden of disease from outdoor air pollution is responsible for around 22,000 premature adult deaths and 163,432 DALYs (disability-adjusted life years) lost. The concentration of major air pollutants in Pakistan, such as NOx, O3, and SO2 have also been increasing significantly over the last two decades. Several studies are also reporting multiple instances of air quality around the major cities of Pakistan being consistently exceeding the national guidelines. During teh year 2019 PM2.5 cocnentrations in the city of Lahore revealed that almost every single day was in exceedance of the WHO and national air quality standards. Although the substantial effects of these rising pollutant concentrations in Pakistan have been stated in a few studies, however, the total extent, nature of contributing factors, and consequences remain inadequately understood. This study aims to use data available from monitoring stations, satellites, and literature to highlight the gaps in our understanding and emphasize the critical challenges associated with poor air quality faced in Pakistan. Topmost is the lack of air quality monitoring systems followed by poor initiatives by policymakers and enforcement agencies. A way forward while addressing these key challenges is also discussed, which focuses on the development of flexible monitoring, new technologies, and monitoring approaches in addition to communications among the various public, private agencies, and all relevant stakeholders.

16.
Virus Res ; 292: 198256, 2021 01 15.
Article de Anglais | MEDLINE | ID: mdl-33285172

RÉSUMÉ

The SD12-F120 is a live-attenuated genotype I strain of Japanese encephalitis virus (JEV) and was obtained by serial passage of wild-type strain SD12 on BHK-21 cells combined with multiple plaque purification and virulence selection in mice. The large scale production and vast clinical trials always demand ideal safety and efficacy profile of live-attenuated vaccines. In the present study, SD12-F120VC has undergone serial passaging of P1-P30 in WHO qualified Vero cells to assess the potential effect of adaptation to growth on Vero cells. The series of experiments showed that vaccine SD12-F120VC (Vero cell adapted) variants have consistently increased in peak virus titer compared to early passages and have good adaptation to growth in Vero cells. The animal experiments showed that Vero cell adapted SD12-F120VC variants have attenuation phenotype in suckling mice and the plaque morphology for all SD12-F120VC variants was small. Vaccination of mice with SD12-F120VC vaccine produced complete protection for homologous SD12 genotype I strain, but failed to give the complete protection of vaccinated mice against the challenge of heterologous N28 genotype III strain. In response to immunization of SD12-F120VC in mice, the neutralizing antibodies titer against homologous SD12-F120VC and SD12 (GI) was higher than heterologous N28 (GIII) strain. The prM protein has 6 amino acid substitutions, of which 5 amino acid changes were confined at the start of the pr domain in the ∼40 amino acids, and some mutations in the pr domain of prM might contribute to Vero cell adaptation. Our findings in this study are important for validation, evaluation and quality control study of live attenuated flaviviruses vaccines and show that Vero cells are a suitable substrate for the production of a safe and stable live-attenuated JEV vaccine.


Sujet(s)
Virus de l'encéphalite japonaise (espèce)/physiologie , Encéphalite japonaise/virologie , Vaccins atténués/génétique , Protéines virales structurales/génétique , Vaccins antiviraux/génétique , Adaptation biologique , Animaux , Anticorps neutralisants/immunologie , Chlorocebus aethiops , Virus de l'encéphalite japonaise (espèce)/génétique , Virus de l'encéphalite japonaise (espèce)/immunologie , Encéphalite japonaise/immunologie , Encéphalite japonaise/prévention et contrôle , Femelle , Génotype , Humains , Souris , Souris de lignée C57BL , Mutation , Passages en série , Vaccins atténués/administration et posologie , Vaccins atténués/immunologie , Cellules Vero , Protéines virales structurales/administration et posologie , Protéines virales structurales/immunologie , Vaccins antiviraux/administration et posologie , Vaccins antiviraux/immunologie
17.
Environ Res ; 193: 110421, 2021 02.
Article de Anglais | MEDLINE | ID: mdl-33160973

RÉSUMÉ

A pneumonia-like disease of unknown origin caused a catastrophe in Wuhan city, China. This disease spread to 215 countries affecting a wide range of people. World health organization (WHO) called it a pandemic and it was officially named as Severe Acute Respiratory Syndrome Corona virus 2 (SARS CoV-2), also known as Corona virus disease (COVID-19). This pandemic compelled countries to enforce a socio-economic lockdown to prevent its widespread. This paper focuses on how the particulate matter pollution was reduced during the lockdown period (23 March to April 15, 2020) as compared to before lockdown. Both ground-based and satellite observations were used to identify the improvement in air quality of Pakistan with primary focus on four major cities of Lahore, Islamabad, Karachi and Peshawar. Both datasets have shown a substantial reduction in PM2.5 pollution levels (ranging from 13% to 33% in case of satellite observations, while 23%-58% in ground-based observations) across Pakistan. Result shows a higher rate of COVID-19 spread in major cities of Pakistan with poor air quality conditions. Yet more research is needed in order to establish linkage between COVID-19 spread and air pollution. However, it can be partially attributed to both higher rate of population density and frequent exposure of population to enhanced levels of PM2.5 concentrations before lockdown period.


Sujet(s)
Polluants atmosphériques , Pollution de l'air , COVID-19 , Polluants atmosphériques/analyse , Pollution de l'air/analyse , Chine , Villes , Contrôle des maladies transmissibles , Surveillance de l'environnement , Humains , Pakistan/épidémiologie , Matière particulaire/analyse , SARS-CoV-2 , Facteurs socioéconomiques
18.
Viruses ; 12(5)2020 05 16.
Article de Anglais | MEDLINE | ID: mdl-32429445

RÉSUMÉ

The phenotypic and genotypic characteristics of a live-attenuated genotype I (GI) strain (SD12-F120) of Japanese encephalitis virus (JEV) were compared with its virulent parental SD12 strain to gain an insight into the genetic changes acquired during the attenuation process. SD12-F120 formed smaller plaque on BHK-21 cells and showed reduced replication in mouse brains compared with SD12. Mice inoculated with SD12-F120 via either intraperitoneal or intracerebral route showed no clinical symptoms, indicating a highly attenuated phenotype in terms of both neuroinvasiveness and neurovirulence. SD12-F120 harbored 29 nucleotide variations compared with SD12, of which 20 were considered silent nucleotide mutations, while nine resulted in eight amino acid substitutions. Comparison of the amino acid variations of SD12-F120 vs SD12 pair with those from other four isogenic pairs of the attenuated and their virulent parental strains revealed that the variations at E138 and E176 positions of E protein were identified in four and three pairs, respectively, while the remaining amino acid variations were almost unique to their respective strain pairs. These observations suggest that the genetic changes acquired during the attenuation process were likely to be strain-specific and that the mechanisms associated with JEV attenuation/virulence are complicated.


Sujet(s)
Virus de l'encéphalite japonaise (espèce)/génétique , Virus de l'encéphalite japonaise (espèce)/pathogénicité , Animaux , Encéphale/virologie , Lignée cellulaire , Cricetinae , Virus de l'encéphalite japonaise (espèce)/classification , Encéphalite japonaise/prévention et contrôle , Encéphalite japonaise/virologie , Femelle , Génotype , Souris , Souris de lignée C57BL , Mutation , Phénotype , Phylogenèse , Spécificité d'espèce , Vaccins atténués/administration et posologie , Vaccins atténués/génétique , Protéines de l'enveloppe virale/génétique , Vaccins antiviraux/administration et posologie , Vaccins antiviraux/génétique , Virulence/génétique , Réplication virale/génétique
19.
Front Microbiol ; 11: 591478, 2020.
Article de Anglais | MEDLINE | ID: mdl-33628201

RÉSUMÉ

Metagenomic analysis of mosquito-borne and mosquito-specific viruses is useful to understand the viral diversity and for the surveillance of pathogens of medical and veterinary importance. Yunnan province is located at the southwest of China and has rich abundance of mosquitoes. Arbovirus surveillance is not conducted regularly in this province particularly at animal farms, which have public health as well as veterinary importance. Here, we have analyzed 10 pools of mosquitoes belonging to Culex tritaeniorhyncus, Aedes aegypti, Anopheles sinensis, and Armigeres subalbatus species, collected from different animal farms located at Yunnan province of China by using metagenomic next-generation sequencing technique. The generated viral metagenomic data reveal that the viral community matched by the reads was highly diverse and varied in abundance among animal farms, which contained more than 19 viral taxonomic families, specific to vertebrates, invertebrates, fungi, plants, protozoa, and bacteria. Additionally, a large number of viral reads were related to viruses that are non-classified. The viral reads related to animal viruses included parvoviruses, anelloviruses, circoviruses, flaviviruses, rhabdoviruses, and seadornaviruses, which might be taken by mosquitoes from viremic animal hosts during blood feeding. Notably, the presence of viral reads matched with Japanese encephalitis virus, Getah virus, and porcine parvoviruses in mosquitoes collected from different geographic sites suggested a potential circulation of these viruses in their vertebrate hosts. Overall, this study provides a comprehensive knowledge of diverse viral populations present at animal farms of Yunnan province of China, which might be a potential source of diseases for humans and domestic animals.

20.
Environ Sci Pollut Res Int ; 27(7): 7328-7340, 2020 Mar.
Article de Anglais | MEDLINE | ID: mdl-31884545

RÉSUMÉ

The elimination of persistent organic pollutants (POPs) obsolete pesticides stockpiles, particularly the organochlorine pesticides (OCPs), is one of the critical environmental issues faced by many developing countries. This pioneering study aimed to investigate the occurrence, source fingerprinting, human health, and ecological risks of OCPs in the surroundings of the lone POPs pesticide destruction facility in Pakistan. The ΣOCPs residual levels in soil ranged from 35.98 to 566.77 ng/g dry weight (dw), with a mean concentration of 174.42 + 111.62 ng/g (dw). The OCPs contamination levels in the soil followed the pattern as ΣHCHs > Σendrins > Σendosulfans > dieldrin > Σheptachlors > ΣDDTs > Σchlordanes > methoxychlor. The ΣHCHs residual concentrations were comparatively higher than the previous national and global soil studies. The recent accumulation of HCHs, DDTs, and heptachlor was observed in the study area as identified by ß-HCH/∑HCHs, (DDE + DDD)/ΣDDTs, heptachlor/Σheptachlor, and heptachlor exo-epoxide/heptachlor ratios. The OCPs' lifetime carcinogenic risk through ingestion, dermal, and inhalation exposure routes ranged from 1.65E-08 to 2.91E-07, whereas the noncarcinogenic hazard quotient (HQ) ranged from 9.12E-05 to 1.61E-03. The risk vulnerability among age groups was in the order: adult > toddler > child > teen > infant. The calculated risk levels were within an acceptable limit of one in a million (1 × 10-6) for carcinogenic risk and HQ < 1 for noncarcinogenic risk. The current OCPs residual levels, especially dieldrin and endrin, exhibited low to medium ecological risks when compared to various worldwide limits. The upsurge of the OCPs' environmental contamination levels over the years and consideration of the food chain transfer might amplify the human health and ecological risks intensities.


Sujet(s)
Polluants environnementaux , Hydrocarbures chlorés , Pesticides , Polluants chimiques de l'eau , Adolescent , Adulte , Enfant d'âge préscolaire , Chine , Humains , Pakistan , Sol
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