Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
1.
Front Immunol ; 15: 1382619, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38779671

RESUMO

Introduction: Antibodies against the SARS-CoV-2 spike protein are a critical immune determinant for protection against the virus. While virus neutralization is a key function of spike-specific antibodies, antibodies also mediate Fc-dependent activities that can play a role in protection or pathogenesis. Methods: This study characterized serum antibody responses elicited after two doses of heterologous adenovirus-vectored (Ad26/ Ad5) vaccines. Results: Vaccine-induced antibody binding titers and Fc-mediated functions decreased over six months, while neutralization titers remained stable. Comparison of antibody isotypes elicited after Ad26/Ad5 vs. LNP-mRNA vaccination and after infection showed that anti-spike IgG1 were dominant and produced to high levels in all groups. The Ad26/Ad5 vaccines also induced IgG4 but not IgG2 and IgG3, whereas the LNP-mRNA vaccines elicited a full Ig spectrum (IgM, IgG1-4, IgA1-2). Convalescent COVID-19 patients had mainly IgM and IgA1 alongside IgG1. Despite these differences, the neutralization potencies against early variants were similar. However, both vaccine groups had antibodies with greater Fc potencies of binding complement and Fcg receptors than the COVID-19 group. The Ad26/Ad5 group also displayed a greater potency of RBD-specific antibody-mediated cellular phagocytosis. Discussion: Antibodies with distinctive quality were induced by different vaccines and infection. The data imply the utility of different vaccine platforms to elicit antibody responses with fine-tuned Fc activities.


Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , Imunoglobulina G , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Humanos , SARS-CoV-2/imunologia , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , COVID-19/imunologia , COVID-19/prevenção & controle , Vacinas contra COVID-19/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Feminino , Imunoglobulina G/imunologia , Imunoglobulina G/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/sangue , Masculino , Fragmentos Fc das Imunoglobulinas/imunologia , Fragmentos Fc das Imunoglobulinas/genética , Ad26COVS1/imunologia , Adulto , Pessoa de Meia-Idade , Adenoviridae/imunologia , Adenoviridae/genética , Vetores Genéticos , Imunoglobulina A/imunologia , Imunoglobulina A/sangue
2.
J Food Sci Technol ; 61(5): 870-878, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38487282

RESUMO

Sorbitol has been the new and emerging adulterant in dairy industry. The main aim of the study was to develop a method to detect sorbitol in milk, which is not affected by other sugars, polyols and formalin. Hence, a thin layer chromatographic (TLC) method was standardized to detect the sorbitol in milk. In the study 90 s duration for the impregnation of Silica gel 60F TLC plates with Cu- ions was found suitable to resolve sorbitol as a distinct spot. The standardized conditions were (1) developing solvent system consisting of n-propanol: ethyl acetate: water (7:1:2), (2) 0.5% of potassium permanganate in 0.1 M NaOH as color developing reagent. (3) Drying temperature (65°C/ 10 min.) after spraying the color developing reagent. The limit of detection was 0.2% of added sorbitol in milk. The standardized method could also detect the sorbitol in the presence of sucrose, glucose and polyols like mannitol and maltitol. In both cow and buffalo milk samples the standardized methodology performed well in detection of sorbitol. The method also performed well in sorbitol spiked formalin preserved milk samples. This method can be an alternative to the other methods involving costly equipment in detecting adulteration of milk with sorbitol.

3.
J Food Sci Technol ; 61(3): 503-515, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38327858

RESUMO

Goat milk has achieved significant place in human diet owing to its enormous therapeutic properties. There exists a scope of value-addition of goat milk to potentiate its health benefits by incorporating herbs and plants. Giloy (Tinospora cordifolia), a traditional medicinal plant with rich bioactive composition, can enhance the bioactive properties and shelf-life of goat milk. To this end, a study was conducted to develop shelf-stable giloy-goat milk beverage (GGB) by adding debittered giloy juice to goat milk (GM) and analyse the detailed product profile including proximate composition, bioactive properties, sensory, rheological, and structural characterisation. GGB resulted in two-fold increase (P < 0.05) in antioxidant activity and total phenolic content, thus enhancing the bioactive properties of the beverage as compared to GM. Further, increase in the particle size of GGB was observed along with components interaction, which was confirmed by FTIR, scanning electron and fluorescent microscopy. Storage stability studies indicated that bioactive properties of GGB remained unaffected (P > 0.05) by the sterilization process up to 90 days and sensory characteristics were not compromised till 105 days of storage. Therefore, the developed GGB is considered to be a shelf-stable beverage that retains its bioactive and sensory properties even after sterilization, making it a promising functional dairy product.

4.
Clin Pediatr (Phila) ; 63(2): 263-271, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37475491

RESUMO

Communication skills are an important part of patient care, but an often neglected part of residency training. Longitudinal active coaching of communication has the potential to effectively improve communication curricula. A novel communication coach curriculum was implemented with approximately half of a pediatric residency class. Residents were coached by both a parent and faculty coach on multiple occasions throughout their intern year. Effectiveness was evaluated through self-assessment, direct observation, chart review, and follow-up phone calls with families. This longitudinal communication coach curriculum was well-received and resulted in increased self-awareness of communication skills. Coachable behaviors improved in intervention residents, and their patients spoke more positively of their experiences with communication. Additionally, these patients were less likely to be readmitted than patients cared for by control residents. A longitudinal communication coaching model is a feasible and effective curriculum for pediatric residents.


Assuntos
Internato e Residência , Tutoria , Humanos , Criança , Comunicação , Currículo , Docentes , Pais
5.
Acad Pediatr ; 24(1): 3-7, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37253414

RESUMO

BACKGROUND: We sought to evaluate changes in In-Training Examination (ITE) scores and associations with clinical work during the COVID-19 pandemic. We hypothesized that residents saw a decrease in clinical encounters during the pandemic and that this would be associated with smaller gains in ITE scores. METHODS: We compared ITE score changes with data on patient notes for three classes of pediatric residents at four residency programs: one not exposed to the pandemic during their intern year who entered residency in 2018, one partially exposed to COVID-19 in March of their intern year (2019-2020), and one that was fully exposed to the pandemic, starting residency in June of 2020. RESULTS: ITE scores on average improved from the PGY1 to PGY2 year in the "no covid" and "partial COVID" cohorts. The "full COVID" cohort had little to no improvement, on average. The total number of patient encounters was not associated with a change in ITE scores from PGY1 to PGY2. There was a small but statistically significant association between change in ITE score and number of inpatient H+P notes. CONCLUSIONS: A drop in ITE scores occurred in pediatric residents who entered residency during the COVID-19 pandemic. This change was largely unrelated to clinical encounter number changes.


Assuntos
COVID-19 , Internato e Residência , Humanos , Criança , Avaliação Educacional , Pandemias , Competência Clínica
6.
Pediatr Rev ; 45(1): 57-59, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-38161152
8.
Front Immunol ; 14: 1271686, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37854587

RESUMO

Introduction: Neutralizing antibodies (Abs) are one of the immune components required to protect against viral infections. However, developing vaccines capable of eliciting neutralizing Abs effective against a broad array of HIV-1 isolates has been an arduous challenge. Objective: This study sought to test vaccines aimed to induce Abs against neutralizing epitopes at the V1V2 apex of HIV-1 envelope (Env). Methods: Four groups of rabbits received a DNA vaccine expressing the V1V2 domain of the CRF01_AE A244 strain on a trimeric 2J9C scaffold (V1V2-2J9C) along with a protein vaccine consisting of an uncleaved prefusion-optimized A244 Env trimer with V3 truncation (UFO-BG.ΔV3) or a V1V2-2J9C protein and their respective immune complexes (ICs). These IC vaccines were made using 2158, a V1V2-specific monoclonal Ab (mAb), which binds the V2i epitope in the underbelly region of V1V2 while allosterically promoting the binding of broadly neutralizing mAb PG9 to its V2 apex epitope in vitro. Results: Rabbit groups immunized with the DNA vaccine and uncomplexed or complexed UFO-BG.ΔV3 proteins (DNA/UFO-UC or IC) displayed similar profiles of Env- and V1V2-binding Abs but differed from the rabbits receiving the DNA vaccine and uncomplexed or complexed V1V2-2J9C proteins (DNA/V1V2-UC or IC), which generated more cross-reactive V1V2 Abs without detectable binding to gp120 or gp140 Env. Notably, the DNA/UFO-UC vaccine elicited neutralizing Abs against some heterologous tier 1 and tier 2 viruses from different clades, albeit at low titers and only in a fraction of animals, whereas the DNA/V1V2-UC or IC vaccines did not. In comparison with the DNA/UFO-UC group, the DNA/UFO-IC group showed a trend of higher neutralization against TH023.6 and a greater potency of V1V2-specific Ab-dependent cellular phagocytosis (ADCP) but failed to neutralize heterologous viruses. Conclusion: These data demonstrate the capacity of V1V2-2J9C-encoding DNA vaccine in combination with UFO-BG.ΔV3, but not V1V2-2J9C, protein vaccines, to elicit homologous and heterologous neutralizing activities in rabbits. The elicitation of neutralizing and ADCP activities was modulated by delivery of UFO-BG.ΔV3 complexed with V2i mAb 2158.


Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Vacinas de DNA , Animais , Coelhos , Anticorpos Anti-HIV , Complexo Antígeno-Anticorpo , Vacinação , Anticorpos Neutralizantes , Epitopos , DNA
9.
J Virol ; 97(9): e0071023, 2023 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-37681958

RESUMO

The envelope (Env) glycoproteins on HIV-1 virions are the sole target of broadly neutralizing antibodies (bNAbs) and the focus of vaccines. However, many cross-reactive conserved epitopes are often occluded on virus particles, contributing to the evasion of humoral immunity. This study aimed to identify the Env epitopes that are exposed/occluded on HIV-1 particles and to investigate the mechanisms contributing to their masking. Using a flow cytometry-based assay, three HIV-1 isolates, and a panel of antibodies, we show that only select epitopes, including V2i, the gp120-g41 interface, and gp41-MPER, are accessible on HIV-1 particles, while V3, V2q, and select CD4bs epitopes are masked. These epitopes become accessible after allosteric conformational changes are induced by the pre-binding of select Abs, prompting us to test if similar conformational changes are required for these Abs to exhibit their neutralization capability. We tested HIV-1 neutralization where the virus-mAb mix was pre-incubated/not pre-incubated for 1 hour prior to adding the target cells. Similar levels of neutralization were observed under both assay conditions, suggesting that the interaction between virus and target cells sensitizes the virions for neutralization via bNAbs. We further show that lectin-glycan interactions can also expose these epitopes. However, this effect is dependent on the lectin specificity. Given that, bNAbs are ideal for providing sterilizing immunity and are the goal of current HIV-1 vaccine efforts, these data offer insight on how HIV-1 may occlude these vulnerable epitopes from the host immune response. In addition, the findings can guide the formulation of effective antibody combinations for therapeutic use. IMPORTANCE The human immunodeficiency virus (HIV-1) envelope (Env) glycoprotein mediates viral entry and is the sole target of neutralizing antibodies. Our data suggest that antibody epitopes including V2q (e.g., PG9, PGT145), CD4bs (e.g., VRC01, 3BNC117), and V3 (2219, 2557) are masked on HIV-1 particles. The PG9 and 2219 epitopes became accessible for binding after conformational unmasking was induced by the pre-binding of select mAbs. Attempts to understand the masking mechanism led to the revelation that interaction between virus and host cells is needed to sensitize the virions for neutralization by broadly neutralizing antibodies (bNAbs). These data provide insight on how bNAbs may gain access to these occluded epitopes to exert their neutralization effects and block HIV-1 infection. These findings have important implications for the way we evaluate the neutralizing efficacy of antibodies and can potentially guide vaccine design.


Assuntos
Anticorpos Amplamente Neutralizantes , Epitopos de Linfócito B , Anticorpos Anti-HIV , Infecções por HIV , HIV-1 , Interações entre Hospedeiro e Microrganismos , Humanos , Anticorpos Monoclonais/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp120 do Envelope de HIV/metabolismo , Infecções por HIV/imunologia , Infecções por HIV/patologia , Infecções por HIV/virologia , HIV-1/química , HIV-1/imunologia , HIV-1/metabolismo , Lectinas/metabolismo , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito B/metabolismo , Vacinas contra a AIDS/química , Vacinas contra a AIDS/imunologia , Vírion/química , Vírion/imunologia , Vírion/metabolismo , Polissacarídeos/metabolismo
10.
Heliyon ; 9(8): e18423, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37533987

RESUMO

Urbanization strongly correlates with land use land cover (LULC) dynamics, which further links to changes in land surface temperature (LST) & urban heat island (UHI) intensity. Each LULC type influences UHI differently with changing climate, therefore knowing this impact & connection is critical. To understand such relations, long temporal studies using remote sensing data play promising role by analysing the trend with continuity over vast area. Therefore, this study is aimed at machine learning centred spatio-temporal analysis of LST and land use indices to identify their intra-urban interaction during 1991-2021 (summer) in Imola city (specifically representing small urban environment) using Landsat-5/8 imageries. It was found that LST in 2021 increased by 38.36% from 1991, whereas average Normalised Difference Built-up Index (NDBI) increased by 43.75%, associating with increased thermal stress area evaluated using ecological evaluation index. Major LULC transformations included green area into agricultural arable-land and built-up. Finally, the modelled output shows that built-up & vegetation index have strongly impacted LST. This study, help to understand the relative impact of land-use dynamics on LST at intra-urban level specifically with respect to the small urban settings. Further assisting in designing and regenerating urban contexts with stable configuration, considering sustainability and liveable climate, for benefit of health of public and fragile population in particular.

11.
Pediatr Rev ; 44(8): 474-476, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37525303
12.
J Dairy Res ; 90(2): 205-212, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37264806

RESUMO

Eggnog, a dairy-based beverage, comprises both milk and egg proteins. We aimed at optimizing the eggnog formulation using Box-Behnken design of response surface methodology. The combined effects of milk (60-75), cream (25-35) and eggnog base (6-8, all three as g 100/ml) were investigated on heat coagulation time, viscosity and thermal gelation temperature. ANOVA indicated that experimental data were well explained by a quadratic model with high check values (R2 > 0.94) and non-significant lack of fit tests. Based on the responses, an optimized formulation of eggnog with 60.0 milk, 25.0 cream and 6.50 eggnog base (as g 100/ml), could be considered best for manufacturing eggnog with desired attributes. This optimized formulation was characterized for physico-chemical, microbial and sensory attributes and the results indicated significantly higher fat and protein content than control formulation, but lesser lactose and total sugar content. Significantly higher viscosity, heat stability and lower thermal gelation temperature were also observed for the optimized formulation. Coliform, yeast and mold, E. coli and Salmonella counts were not detected in any sample but a significantly lower total plate count was observed for the optimized formulation.


Assuntos
Escherichia coli , Leite , Animais , Leite/química , Temperatura , Bebidas/análise , Temperatura Alta
13.
bioRxiv ; 2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-36711466

RESUMO

The envelope glycoproteins (Env) on HIV-1 virions are the sole target of broadly neutralizing antibodies (bNAb) and the focus of vaccines. However, many cross-reactive conserved epitopes are often occluded on virus particles, contributing to the evasion of humoral immunity. This study aimed to identify the Env epitopes that are exposed/occluded on HIV-1 particles and to investigate the mechanisms contributing to their masking. Using a flow cytometry-based assay, three HIV-1 isolates, and a panel of antibodies, we show that only select epitopes including V2i, gp120-g41 interface, and gp41-MPER are accessible on HIV-1 particles, while V3, V2q, and select CD4bs epitopes are masked. These epitopes become accessible after allosteric conformational changes are induced by pre-binding of select Abs, prompting us to test if similar conformational changes are required for these Abs to exhibit their neutralization capability. We tested HIV-1 neutralization where virus-mAb mix was pre-incubated/not pre-incubated for one hour prior to adding the target cells. Similar levels of neutralization were observed under both assay conditions, suggesting that the interaction between virus and target cells sensitizes the virions for neutralization via bNAbs. We further show that lectin-glycan interactions can also expose these epitopes. However, this effect is dependent on the lectin specificity. Given that, bNAbs are the ideal for providing sterilizing immunity and are the goal of current HIV-1 vaccine efforts, these data offer insight on how HIV-1 may occlude these vulnerable epitopes from the host immune response. In addition, the findings can guide the formulation of effective antibody combinations for therapeutic use.

14.
Orbit ; 42(1): 30-41, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35192435

RESUMO

PURPOSE: To study the risk factors for development of COVID-19 associated rhino-orbital-cerebral mucormycosis (ROCM) during the COVID-19 pandemic in India. METHODS: Multi-centric retrospective case-control study conducted from October 2020 to May 2021. Cases comprised of consecutive patients of COVID-19-associated ROCM (CA-ROCM) presenting at the participating ophthalmic institutes. Controls comprised of COVID-19-positive or COVID-19-recovered patients who did not develop ROCM. Comparative analysis of demographic, COVID-19 infection, treatment parameters and vaccination status between cases and controls performed. Clinical and imaging features of CA-ROCM analyzed. RESULTS: There were 179 cases and 361 controls. Mean age of presentation in cases was 52.06 years (p = .001) with male predominance (69.83%, p = .000011). Active COVID-19 infection at the time of presentation of ROCM (57.54%, p < .0001), moderate to severe COVID-19 (p < .0001), steroid administration (OR 3.63, p < .00001), uncontrolled diabetes (OR 32.83, p < .00001), random blood sugar >178 mg/dl were associated with development of CA-ROCM. Vaccination showed a protective effect (p = .0049). In cases with intracranial or cavernous sinus extension there was history of steroid administration (OR 2.89, p = .024) and orbital apex involvement on imaging (OR 6.202, p = .000037) compared to those with only rhino-orbital disease. CONCLUSION: Male gender, active COVID-19 infection, moderate or severe COVID-19, uncontrolled diabetes, steroid administration during COVID-19 treatment are risk factors for developing rhino-orbital-cerebral mucormycosis. Vaccination is protective. Random blood sugar of >178 mg/dl in COVID-19 positive or recovered patients should warrant close observation and early detection of ROCM. Presence of ophthalmoplegia, blepharoptosis at first clinical presentation and orbital apex involvement on imaging are associated with intracranial extension in ROCM.


Assuntos
COVID-19 , Oftalmopatias , Mucormicose , Doenças Orbitárias , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Pandemias , Glicemia , Tratamento Farmacológico da COVID-19 , Estudos de Casos e Controles , Mucormicose/epidemiologia , Estudos Retrospectivos , COVID-19/epidemiologia , Fatores de Risco , Doenças Orbitárias/diagnóstico por imagem , Doenças Orbitárias/epidemiologia , Índia/epidemiologia , Esteroides
15.
Vaccines (Basel) ; 10(12)2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36560493

RESUMO

Background: Monkeypox is a global public health concern, given the recent outbreaks in non-endemic countries where little scientific evidence exists on the disease. Specifically, there is a lack of data on asymptomatic monkeypox virus infection. This study aims to evaluate the overall prevalence of asymptomatic monkeypox virus infection. Methods: In this systematic review and meta-analysis, we performed an extensive literature search in PubMed, Scopus, Web of Science, ProQuest, EMBASE, EBSCOHost, Cochrane, and preprint servers (medRxiv, arXiv, bioRxiv, BioRN, ChiRxiv, ChiRN, and SSRN) and assessed all published articles till September 2022. Primary studies reporting monkeypox infections among asymptomatic participants were included after quality assessment. The characteristics of the study and information on the number of cases and symptomatic status were extracted from the included studies. The heterogeneity between studies was assessed using the I2 statistic. Publication bias was analyzed using funnel plots and Egger regression tests. The primary outcome was the pooled prevalence of asymptomatic infections within the examined population. Results: A total of 16 studies were included for qualitative synthesis, while five studies, including 645 individuals, were included for quantitative synthesis. There was substantial heterogeneity between studies (I2 = 94.86%; p < 0.01), with a pooled percentage of asymptomatic infections in the studied population of 10.2% (95%CI, 2.5−17.9%). Conclusion: This meta-analysis suggests that many people infected with the monkeypox virus are asymptomatic and difficult to detect. Therefore, prompt detection of these cases of monkeypox virus and appropriate subsequent management is of utmost importance to global public health.

17.
Food Chem ; 393: 133355, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35667181

RESUMO

The study aimed at evaluation of ß-galactosidase activity for lactose hydrolysis (DH) and galactooligosaccharide (GOS) formation at 7 °C. ß-galactosidase derived from K. lactis was more effective than B. lichenformis for DH and GOS formation in 16% lactose solution. ß-galactosidase from K. lactis exhibited 96.61% DH and 7.28% GOS production after 12 h of reaction and hence was utilized for lactose hydrolysis in concentrated skim milk (40% total solids). Use of 9.53 U/mL enzyme resulted in significantly high DH (97.06%) after 12 h with 4.90 g/L of residual lactose. However, maximum GOS formation of 12.01% with 94.74% DH was obtained after 4 h. Further increase in reaction time up to 12 h resulted in breakdown of tri and tetrasaccharide GOS, thereby, reducing GOS content. Hence, reaction time of 12 h was finalized to obtain maximum DH along with additional benefit of GOS formation.


Assuntos
Lactose , Leite , Animais , Galactose/metabolismo , Hidrólise , Lactose/metabolismo , Leite/metabolismo , Oligossacarídeos/metabolismo , beta-Galactosidase/metabolismo
18.
Front Robot AI ; 9: 873446, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35558156

RESUMO

We propose a segment design that combines two distinct characteristics of tendon-driven continuum robots, i.e. variable length and non-straight tendon routing, into a single segment by enabling rotation of its backbone. As a result, this segment can vary its helical tendon routing and has four degrees-of-freedom, while maintaining a small-scale design with an overall outer diameter of 7 mm thanks to an extrinsic actuation principle. In simulation and on prototypes, we observe improved motion capabilities, as evidenced by position redundancy and follow-the-leader deployment along spatially tortuous paths. To demonstrate the latter on a physical prototype, a simple, yet effective area-based error measure for follow-the-leader deployment is proposed to evaluate the performance. Furthermore, we derive a static model which is used to underpin the observed motion capabilities. In summary, our segment design extends previous designs with minimal hardware overhead, while either archiving similar accuracy in position errors and planar follow-the-leader deployment, or exhibiting superior motion capabilities due to position redundancy and spatial follow-the-leader deployment.

19.
Viruses ; 14(4)2022 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-35458538

RESUMO

HIV-1 Env signal peptide (SP) is an important contributor to Env functions. Env is generated from Vpu/Env encoded bicistronic mRNA such that the 5' end of Env-N-terminus, that encodes for Env-SP overlaps with 3' end of Vpu. Env SP displays high sequence diversity, which translates into high variability in Vpu sequence. This study aimed to understand the effect of sequence polymorphism in the Vpu-Env overlapping region (VEOR) on the functions of two vital viral proteins: Vpu and Env. We used infectious molecular clone pNL4.3-CMU06 and swapped its SP (or VEOR) with that from other HIV-1 isolates. Swapping VEOR did not affect virus production in the absence of tetherin however, presence of tetherin significantly altered the release of virus progeny. VEOR also altered Vpu's ability to downregulate CD4 and tetherin. We next tested the effect of these swaps on Env functions. Analyzing the binding of monoclonal antibodies to membrane embedded Env revealed changes in the antigenic landscape of swapped Envs. These swaps affected the oligosaccharide composition of Env-N-glycans as shown by changes in DC-SIGN-mediated virus transmission. Our study suggests that genetic diversity in VEOR plays an important role in the differential pathogenesis and also assist in immune evasion by altering Env epitope exposure.


Assuntos
HIV-1 , Antígeno 2 do Estroma da Médula Óssea/genética , Proteínas Ligadas por GPI/genética , Genes env , HIV-1/fisiologia , Proteínas do Vírus da Imunodeficiência Humana/genética , Proteínas do Vírus da Imunodeficiência Humana/metabolismo , Evasão da Resposta Imune , Sinais Direcionadores de Proteínas/genética , Proteínas Virais Reguladoras e Acessórias/genética , Proteínas Virais Reguladoras e Acessórias/metabolismo
20.
J Dairy Res ; : 1-6, 2022 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-35236519

RESUMO

The work presented in this research communication was carried out to prepare low calorie synbiotic milk beverage by optimizing water and sugar level and to investigate the effect on its storage ability of different packaging materials (polypropylene, high impact polystyrene, high-density polyethylene and glass). Addition of both water and sugar significantly (P < 0.05) affected the viscosity, probiotic count and sensory properties. Based on the findings, 40% water and 8% sugar level were optimized for the preparation of the beverage. Apparent viscosity and acidity increased whilst pH and probiotic counts declined during storage, irrespective of packaging materials. The prepared beverage remained most acceptable at refrigeration temperature up to a period of 15 and 12 d when packaged in glass and high impact polystyrene, respectively. Furthermore, it retained a minimum recommended level of probiotic (7 log cfu/ml) during storage for 15 d at 4 °C.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA