22 research outputs found

    Generation of precision-cut slice cultures of human placenta.

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    We present a protocol to generate an advanced ex vivo model of human placenta. We use a vibrating tissue slicer to obtain precision-cut slices representative of the entire thickness of human placenta. This approach delivers standardized cultures with a preserved microstructure and cellular composition comparable to the native tissue. We applied this system to study SARS-CoV-2 infection at the maternal-fetal interface. Moreover, this system can be used to investigate the basic functions of the human placenta in health and disease. For complete details on the use and execution of this protocol, please refer to Fahmi et al. (2021)

    Disrupting the HDAC6-ubiquitin interaction impairs infection by influenza and Zika virus and cellular stress pathways.

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    The deacetylase HDAC6 has tandem catalytic domains and a zinc finger domain (ZnF) binding ubiquitin (Ub). While the catalytic domain has an antiviral effect, the ZnF facilitates influenza A virus (IAV) infection and cellular stress responses. By recruiting Ub via the ZnF, HDAC6 promotes the formation of aggresomes and stress granules (SGs), dynamic structures associated with pathologies such as neurodegeneration. IAV subverts the aggresome/HDAC6 pathway to facilitate capsid uncoating during early infection. To target this pathway, we generate designed ankyrin repeat proteins (DARPins) binding the ZnF; one of these prevents interaction with Ub in vitro and in cells. Crystallographic analysis shows that it blocks the ZnF pocket where Ub engages. Conditional expression of this DARPin reversibly impairs infection by IAV and Zika virus; moreover, SGs and aggresomes are downregulated. These results validate the HDAC6 ZnF as an attractive target for drug discovery

    Disrupting the HDAC6-ubiquitin interaction impairs infection by influenza and Zika virus and cellular stress pathways

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    The deacetylase HDAC6 has tandem catalytic domains and a zinc finger domain (ZnF) binding ubiquitin (Ub). While the catalytic domain has an antiviral effect, the ZnF facilitates influenza A virus (IAV) infection and cellular stress responses. By recruiting Ub via the ZnF, HDAC6 promotes the formation of aggresomes and stress granules (SGs), dynamic structures associated with pathologies such as neurodegeneration. IAV subverts the aggresome/HDAC6 pathway to facilitate capsid uncoating during early infection. To target this pathway, we generate designed ankyrin repeat proteins (DARPins) binding the ZnF; one of these prevents interaction with Ub in vitro and in cells. Crystallographic analysis shows that it blocks the ZnF pocket where Ub engages. Conditional expression of this DARPin reversibly impairs infection by IAV and Zika virus; moreover, SGs and aggresomes are downregulated. These results validate the HDAC6 ZnF as an attractive target for drug discovery

    The effect of feed-based vaccination on tilapia farm endemic for streptococcosis

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    A tilapia farm experiencing endemic streptococcosis was selected to study the effect of vaccination with a feed-based vaccine on naturally ocurring streptococcosis. A total of 9000 red tilapia, Oreochromis niloticus × Oreochromis mossambicus of 100 ± 20 g were divided into 9 cages. Fish of Group 1 in cages 1, 2 and 3 were not vaccinated. Group 2 in cages 4, 5 and 6 were vaccinated on days 0 and 14 (single booster) while Group 3 in cages 7, 8 and 9 were vaccinated on days 0, 14 and 42 (double booster). Vaccination was done by oral administration of the feed-based bacterin vaccine at 4% bodyweight. Samples of serum for antibody study and the brain, eyes and kidney for bacterial isolation were collected at 14-day intervals. The study was carried out during the critical months between April and June. Following vaccination and booster, there was significant (p < 0.05) increase in the antibody levels in all vaccinated groups from week 1 that reached the peak at week 3 before declining gradually until week 6. However, second booster on week 6 significantly (p < 0.05) increased the antibody level that remained high until the end of the 16-week study period (double booster). Streptococcus agalactiae was isolated at the start of the experiment (day 0) at an average of 10 ± 5.0% of the sampled fish. In week 4, the isolation rate was 13 ± 5.7% but increased to 18 ± 7.6% in week 8, to 25 ± 10.0% in week 10, to 28 ± 5.8% in week 12 and 25 ± 7.3% in week 14. The average isolation rate was 28 ± 7.2%, 18 ± 7.1% and 13 ± 8.2% of the fish sampled from unvaccinated, single booster and double booster groups, respectively. At the end of the study period, the survival rate was 45.2 ± 2.45% for unvaccinated, 65.3 ± 4.8% for single booster and 75.1 ± 2.1% for double booster groups. Vaccinating fish in endemic farm might not eliminate the disease but was able to significantly improve the survival rate

    The presence of vibrionaceae, betanodavirus and iridovirus in marine cage-cultured fish: role of fish size, water physicochemical parameters and relationships among the pathogens

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    The study determines the presence of Vibrionaceae, Betanodavirus and Iridovirus in marine cage-cultured fish, while identifying the roles of fish size, water physicochemical parameters and relationships among the pathogens itself. Cultured grouper and snapper were randomly sampled from a commercial fish farm between February and December 2014. The total body weight and length of individual fish were measured. The kidney, liver and spleen were sampled for bacteria isolation, while for viral identification, the sample of brain, eye, kidney and spleen were used. Water physicochemical parameters during the sampling activities were also determined. Laboratory results revealed isolations of multiple pathogens including Vibrio alginolyticus, V. vulnificus, Photobacterium damselae subsp. damselae (PD), Nervous Necrosis Virus (NNV) and Iridovirus (IV) at low to high prevalence throughout the study period. The weight of affected groupers ranged between 98 g and 719 g, while snappers between 67 g and 982 g. There was a weak and moderate negative correlation between the grouper’s weight and the presence of NNV (R = −0.3684; P 0.05) difference was noted in the rate of isolated pathogens between groupers and snappers, and between the pathogens affecting snappers. However, detection of IV in groupers was significantly (P < 0.05) higher than V. alginolyticus, V. vulnificus and PD. Isolations of V. vulnificus in groupers showed strong and moderate positive correlations with isolations of PD (R = 0.7069; P < 0.05) and IV (R = 0.6665; P < 0.05), respectively. In snappers, there was strong positive correlation between isolation of V. alginolyticus and NNV (R = 0.7526; P < 0.05). Multivariate analyses showed that water temperature, dissolved oxygen, ammonia, iron and nitrite were the most significant water physicochemical parameters associated with presence of these pathogens

    Development of acid-base-enzyme pretreatment and hydrolysis of palm oil mill effluent for bioethanol production: a review

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    Nowadays, palm oil mill effluent (POME) is the main water stream pollutant in Malaysia. This paper reviews to development in the methods of bioethanol production from POME by acid-base-enzyme pretreatment and hydrolysis processes. The methods currently used to treat POME are inefficient either of cost or in terms of environmental preservation. Several techniques of pretreatment of POME are discussed, where the structure of POME is breakdown and make it more accessible to the cellulase enzymes. Generally, hydrolysis process is used as a mild acid-base-enzyme for monomeric sugar production from POME. The acid-base-enzyme consists of H2SO4, NaOH and cellulase enzymes to run the hydrolysis process. In this paper, different strategies are also described for hydrolysis processes, including concentrate acid hydrolysis, dilute acid hydrolysis and enzymatic hydrolysis. In addition, the production of bioethanol by fermentation of sugars obtained from the hydrolysis process are discussed and it points out some key properties that should be targeted for cost effective and innovative pretreatment processes

    Potential Role of Microfibrillar-Associated Protein 4, Fibrotic Indices and Oxidative Stress in Hepatocellular Carcinoma

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    Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality worldwide. In an attempt to understand some potential mechanisms of persistence and oncogenicity of Hepatitis C virus (HCV)-related HCC, microfibrillar-associated protein 4 (MFAP4), fibrotic indices and oxidative status biomarkers were assessed in the sera of 50 patients with HCV-associated HCC, 25 patients with HCV-related liver cirrhosis and 15 healthy individuals. Serum oxidized Coenzyme Q10 (CoQ10) and malondialdehyde showed significant elevation in HCC patients compared to the control group (p &lt; 0.001), as well as cirrhotic patients (p &lt; 0.05 and p &lt; 0.001, respectively), while serum glutathione content and superoxide dismutase activity were significantly decreased in HCC patients compared to the control group (p &lt; 0.001). Serum MFAP4, aspartate aminotransferase to platelet ratio index (APRI), fibrosis index based on the 4 factors (FIB-4) and Forns index showed significant increase in HCC patients compared to the control group (p &lt; 0.001), while only APRI and FIB-4 were significantly different between HCC and cirrhotic patients (p &lt; 0.05), with a sensitivity of 86% and 92%, respectively, at cut off &ge;0.7 for APRI and &ge;1.57 for FIB-4. Therefore, increasing oxidative stress and fibrosis might mediate HCV induced cirrhosis and HCC. APRI and FIB-4 may be used as a simple non-expensive formula for the screening of HCC rather than MFAP4

    Assessment of serum vitamin D level in patients with systemic lupus erythematosus

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    Objective To evaluate the serum level of vitamin D in patients with systemic lupus erythematosus (SLE) and its relationship with disease activity. Patients and methods Forty patients suffering from SLE were enrolled in this study (group I). They were further divided into two subgroups according to the SLE disease activity index (SLEDAI) score: group Ia with respect to disease activity and group Ib with respect to disease remission. Another 20 age-matched and sex-matched healthy individuals were chosen as control group II. All patients underwent complete medical history taking and thorough clinical examination; the disease activity was assessed by the use of SLEDAI score. Serum vitamin D level in all patients and controls was measured. Results Vitamin D level was significantly higher in controls than in patients. The vitamin D deficiency was highly prevalent among patients with disease activity than in the remission group. There was highly significant inverse correlation between vitamin D level and SLEDAI score in the patient group. Vitamin D level correlated inversely with C reactive protein (CRP) and anti-dsDNA in the disease activity group, whereas it correlated positively with C3. Conclusion Vitamin D deficiency is prevalent in SLE patients more than in healthy controls; vitamin D deficiency is highly prevalent among patients with disease activity than in the remission group, and vitamin D level correlated inversely with disease activity, which suggest that inadequate vitamin D level, among other factors, probably contributed to the development of active disease in patients with SLE

    Absence of Zika virus among pregnant women in Vietnam in 2008.

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    BACKGROUND Despite being first identified in 1947, Zika virus-related outbreaks were first described starting from 2007 culminating with the 2015 Latin American outbreak. Hypotheses indicate that the virus has been circulating in Asia for decades, but reports are scarce. METHODS We performed serological analysis and screened placental samples isolated in 2008 for the presence of Zika virus from pregnant women in Ho Chi Minh City (Vietnam). RESULTS None of the placental samples was positive for Zika virus. Four serum samples out of 176 (2.3%) specifically inhibited Zika virus, with variable degrees of cross-reactivity with other flaviviruses. While one of the four samples inhibited only Zika virus, cross-reactivity with other flaviviruses not included in the study could not be ruled out. CONCLUSION Our results support the conclusion that the virus was not present among pregnant women in the Vietnamese largest city during the initial phases of the epidemic wave
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