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1.
Artigo em Inglês | MEDLINE | ID: mdl-38987489

RESUMO

PURPOSE: Immune cells are capable of eliminating leukemic cells, as evidenced by outcomes in hematopoietic cell transplantation (HCT). However, patients who fail induction therapy will not benefit from HCT due to their minimal residual disease (MRD) status. Thus, we aimed to develop an immunomodulatory agent to reduce MRD by activating immune effector cells in the presence of leukaemia cells via a novel fusion protein that chimerises two clinically tolerated biologics: a CD33 antibody and the IL15Ra/IL15 complex (CD33xIL15). METHODS: We generated a set of CD33xIL15 fusion protein constructs with varying configurations and identified those with the best in vitro AML-binding, T cell activation, and NK cell potentiation. Using 89Zr-immunoPET imaging we then evaluated the biodistribution and in vivo tumour retention of the most favourable CD33xIL15 constructs in an AML xenograft model. Ex vivo biodistribution studies were used to confirm the pharmacokinetics of the constructs. RESULTS: Two of the generated fusion proteins, CD33xIL15 (N72D) and CD33xIL15wt, demonstrated optimal in vitro behaviour and were further evaluated in vivo. These studies revealed that the CD33xIL15wt candidate was capable of being retained in the tumour for as long as its parental CD33 antibody, Lintuzumab (13.9 ± 3.1%ID/g vs 18.6 ± 1.1%ID/g at 120 h). CONCLUSION: This work demonstrates that CD33xIL15 fusion proteins are capable of targeting leukemic cells and stimulating local T cells in vitro and of concentrating in the tumour in AML xenografts. It also highlights the importance of 89Zr-immunoPET to guide the development and selection of tumour-targeted antibody-cytokine fusion proteins.

2.
J Agromedicine ; : 1-5, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38904321

RESUMO

OBJECTIVES: The aim of this study was to analyze how farmworkers are represented in stock photos available in commercial libraries for use in agricultural health and safety education materials. METHODS: We searched for images in five commercial stock photo libraries using the terms "farmworkers" and "women farmworkers" in April 2022. We used quantitative content analysis. We coded each image for containing a visible face, age, gender, skin tone, work activity, mechanization, presence of hazards, technology use, and protective equipment/clothing after establishing inter-coder reliability. We used descriptive statistics to characterize the available stock photos. RESULTS: We identified stock photos (n = 127) in three databases (Adobe Stock Images, Canva, and Getty Images). Two databases (Microsoft Office Image Library and Pixabay) had no relevant images at the time of the search. Only half of the photos analyzed contained a face. Light skin tones and young or middle-aged adults were more common. A majority of farming activities represented in photos were manual tasks (e.g., harvesting) with few depictions of equipment, hazards, and protective equipment/clothing. CONCLUSIONS: Health and safety professionals tasked with developing materials for education in agricultural settings face a severe lack of imagery pertinent to the realistic conditions of farmworkers in the United States. In the databases we reviewed, photos displaying human faces, photos showing a range of skin tones and ages, and photos displaying an array of different farm hazards are likely not sufficient for material development. Health and safety professionals may benefit from sharing photos from their own work with other professionals and allocating resources for professional photo shoots in their material development projects.

3.
J Immunother Cancer ; 12(5)2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38772686

RESUMO

BACKGROUND: CD33 is a tractable target in acute myeloid leukemia (AML) for chimeric antigen receptor (CAR) T cell therapy, but clinical success is lacking. METHODS: We developed 3P14HLh28Z, a novel CD33-directed CD28/CD3Z-based CAR T cell derived from a high-affinity binder obtained through membrane-proximal fragment immunization in humanized mice. RESULTS: We found that immunization exclusively with the membrane-proximal domain of CD33 is necessary for identification of membrane-proximal binders in humanized mice. Compared with clinically validated lintuzumab-based CAR T cells targeting distal CD33 epitopes, 3P14HLh28Z showed enhanced in vitro functionality as well as superior tumor control and increased overall survival in both low antigen density and clinically relevant patient-derived xenograft models. Increased activation and enhanced polyfunctionality led to enhanced efficacy. CONCLUSIONS: Showing for the first time that a membrane-proximal CAR is superior to a membrane-distal one in the setting of CD33 targeting, our results demonstrate the rationale for targeting membrane-proximal epitopes with high-affinity binders. We also demonstrate the importance of optimizing CAR T cells for functionality in settings of both low antigen density and clinically relevant patient-derived models.


Assuntos
Imunoterapia Adotiva , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico , Humanos , Animais , Camundongos , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Imunoterapia Adotiva/métodos , Receptores de Antígenos Quiméricos/imunologia , Receptores de Antígenos Quiméricos/metabolismo , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/terapia , Linfócitos T/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto , Linhagem Celular Tumoral
4.
LGBT Health ; 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38800875

RESUMO

Purpose: Tobacco use is a major health disparity for lesbian, gay, bisexual, and transgender (LGBT) populations compared with heterosexual/cisgender populations. In this scoping review, we aimed to determine if LGBT tobacco use disparities are improving or worsening over time and if trends in disparities differed across subgroups. Methods: We included articles that longitudinally explored youth and adult LGB tobacco use in the United States and Canada after searching four databases and capturing records through July 2022. Two reviewers independently screened the title/abstract and full text of 2326 and 45 articles, respectively. Eleven articles from 18 larger assessments met inclusion criteria, spanning data collection from 1996 to 2020. Results: All studies consistently demonstrated tobacco disparities for LGB populations. No articles examined longitudinal transgender tobacco disparities. Most studies focused on smoking combustible cigarettes. Disparities in heavy or daily use for all LGB youth subgroups compared with heterosexual samples appear to be shrinking longitudinally. Results for early-onset, current, and lifetime smoking were less consistent. Adult evidence was relatively sparse; however, after 2010, studies show diminishing disparities over time, except for current smoking by bisexual women. Conclusions: Large tobacco use disparities persist for LGB populations, although the size of disparities may be decreasing for some groups. Initiatives for lesbian and bisexual women and girls should be prioritized, in addition to interventions addressing LGB smoking broadly. Surveillance instruments should uniformly and consistently assess LGBT identities and tobacco use behaviors.

5.
J Infect Dev Ctries ; 18(4): 640-644, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38728634

RESUMO

INTRODUCTION: Tetanus is a rather rare disease in the Western countries thanks to widespread vaccination programs and the availability of prophylactics for patients with tetanus-prone injuries. The few cases that do occur are promptly managed in intensive care units (ICUs). However, tetanus is not so rare in developing countries, where access to a suitable level of care is limited. An unstable political situation can be a significant factor influencing patient outcomes. CASE REPORT: A ten-year-old boy presented at the EMERGENCY hospital in Lashkar-Gah (southern Afghanistan) with generalized tetanus after falling off his bicycle. In response to his rapidly deteriorating general conditions - respiratory failure and hemodynamic instability - the patient was urgently transferred by ambulance to the ICU at the EMERGENCY hospital in Kabul (northern Afghanistan). The patient was placed on mechanical ventilation while receiving intravenous sedation and pharmacologic paralysis for almost four weeks. A prolonged infusion of a high dose of magnesium sulphate and labetalol was also given to counteract autonomic dysfunction. Multiple complications related to the long stay in the ICU were observed and promptly addressed. During this period, several mass casualties took place in Kabul, which stretched the hospital's surge capacity. The patient was discharged and accompanied back to Lashkar-Gah three months after his admission to the hospital. CONCLUSION: This case report shows some of the many difficulties that arise when managing a patient with severe tetanus in a war zone where resources are limited.


Assuntos
Tétano , Humanos , Tétano/tratamento farmacológico , Masculino , Afeganistão , Criança , Respiração Artificial , Sulfato de Magnésio/uso terapêutico , Sulfato de Magnésio/administração & dosagem , Unidades de Terapia Intensiva
6.
Int J Obes (Lond) ; 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615158

RESUMO

BACKGROUND/AIMS: Coronary heart disease morbidity and mortality are higher in people of South Asian origin than in those of African origin. We investigated whether as young adults without diabetes, people in Mauritius of South Asian descent (Indians) would show a more adverse cardiovascular risk profile that those of predominantly African descent (Creoles), and whether this could be explained by ethnic differences in visceral adiposity or other fat distribution patterns. METHODS: The study was conducted in 189 young non-physically active adults, with the following measurements conducted after an overnight fast: anthropometry (weight, height, waist circumference), whole-body and regional body composition by dual-energy x-ray absorptiometry, blood pressure, and blood assays for glycemic (glucose and HbA1c) and lipid profile (triglycerides and cholesterols). RESULTS: The results indicate higher serum triglycerides and lower HDL cholesterol in men than in women, and in Indians than in Creoles (p < 0.001). No significant differences due to sex or ethnicity are observed in body mass index and waist circumference, but indices of visceral adiposity (visceral/android, visceral/subcutaneous) and visceral-to-peripheral adiposity ratio (visceral/gynoid, visceral/limb) were significantly higher in men than in women, and in Indians than in Creoles. The significant effects of sex and ethnicity on blood lipid profile were either completely abolished or reduced to a greater extent after adjusting for the ratio of visceral-to-peripheral adiposity than for visceral adiposity per se. CONCLUSIONS: In young adults in Mauritius, Indians show a more adverse pattern of body fat distribution and blood lipid risk profile than Creoles. Differences in their fat distribution patterns, however, only partially explain their differential atherogenic lipid risk profile, amid a greater impact of visceral-to-peripheral adiposity ratio than that of visceral adiposity per se on sex and ethnic differences in cardiovascular risks; the former possibly reflecting the ratio of hazardous (visceral) adiposity and protective (peripheral) superficial subcutaneous adiposity.

7.
Heliyon ; 9(11): e22533, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38074888

RESUMO

Single crystals of Cu2ZnGeSe4 and Cu2ZnGeS4 solid solutions were developed and successfully obtained using the chemical vapor transfer method, with iodine acting as a transporter. The structure, compositional dependences of lattice parameters, pycnometric and X-ray densities and microhardness were determined. The chemical composition determined by the X-ray microanalysis satisfactorily corresponds to the nominal one with a tolerance of ±5 %. The XRD analysis showed that all the obtained compounds and their solid solutions have unit cell described by tetragonal symmetry. The attice parameters were found to be а = 5.342 ± 0.005 Å, с = 10.51 ± 0.01 Å for the Сu2ZnGeS4 compound and а = 5.607 ± 0.005 Å, с = 11.04 ± 0.01 Å for the Cu2ZnGeSe4, respectively. Structural studies confirmed the validity of the Vegard's law in relation to the obtained samples. The pycnometric densities of ∼4.28 g/cm3 for the Cu2ZnGeS4 and ∼5.46 g/cm3 for the Cu2ZnGeSe4 were found to be slightly less than their X-ray densities of ∼4.32 g/cm3 and ∼5.52 g/cm3, respectively. The maximum microhardness of ∼398 kg/mm2 for these solid solutions corresponds to x = 0.60. The melt point of the solid solutions increases from ∼1180 °C for the Сu2ZnGeSe4 up to ∼1400 °C for the Сu2ZnGeS4. Based on X-ray fluorescence analysis and DTA data, the phase diagram of the Cu2ZnGeSe4-Cu2ZnGeS4 system was constructed. Analysis of the obtained diagram indicates its first type according to Rozbom's classification.

8.
Obesity (Silver Spring) ; 31(5): 1179-1182, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37140404

RESUMO

The concept of dual-adaptive thermogenesis underlying metabolic adaptation to prolonged energy deficit posits that there are two control systems that govern energy sparing: a rapid-reacting system to energy deficit and a slow-reacting system to fat store depletion. The latter control system, referred to as the "adipose-specific" control of thermogenesis, contributes to accelerating fat store replenishment (catch-up fat) during weight regain. The case is put forward here that, whereas adaptive thermogenesis during weight loss results primarily from central suppression of the sympathetic nervous system and hypothalamic-pituitary-thyroid axis, during weight regain it operates primarily through peripheral tissue resistance to the actions of this neurohormonal network. Emerging evidence that altered deiodination of thyroid hormones within the skeletal muscle and liver is a key determinant of such peripheral resistance therefore offers entry points toward elucidating the molecular mechanisms that underlie the adipose-specific control of thermogenesis and unraveling tissue-specific targets to counter obesity recidivism.


Assuntos
Tecido Adiposo , Metabolismo Energético , Humanos , Tecido Adiposo/metabolismo , Metabolismo Energético/fisiologia , Obesidade/metabolismo , Aumento de Peso , Hormônios Tireóideos/metabolismo , Termogênese/fisiologia
9.
Nat Commun ; 14(1): 433, 2023 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-36702826

RESUMO

Hepatitis C virus (HCV) uses a hybrid entry mechanism. Current structural data suggest that upon exposure to low pH and Cluster of Differentiation 81 (CD81), the amino terminus of envelope glycoprotein E2 becomes ordered and releases an internal loop with two invariant aromatic residues into the host membrane. Here, we present the structure of an amino-terminally truncated E2 with the membrane binding loop in a bent conformation and the aromatic side chains sequestered. Comparison with three previously reported E2 structures with the same Fab indicates that this internal loop is flexible, and that local context influences the exposure of hydrophobic residues. Biochemical assays show that the amino-terminally truncated E2 lacks the baseline membrane-binding capacity of the E2 ectodomain. Thus, the amino terminal region is a critical determinant for both CD81 and membrane interaction. These results provide new insights into the HCV entry mechanism.


Assuntos
Hepacivirus , Hepatite C , Humanos , Hepacivirus/metabolismo , Ligação Proteica , Proteínas do Envelope Viral/metabolismo , Tetraspanina 28/química , Tetraspanina 28/metabolismo
10.
Ghana Med J ; 57(4): 293-299, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38957848

RESUMO

Objectives: To compare clinical characteristics of COVID-19 among vaccinated and unvaccinated patients in a major treatment facility in Ghana. Design: A retrospective study drawing on data from COVID-19 patients' records visiting the facility from March 2021 to December 2021. Setting: Ghana Infectious Disease Centre, Ga East Municipality, Greater Accra Region, Ghana. Participants: In-patients and outpatients who reported to the facility from 1st March 2021 to December 2021 were included in the study, and patients with missing data on vaccination were excluded. Outcome measures: underlying conditions, symptoms, case management information, hospital service rendered (OPD, HDU or ICU), length of hospital stay, treatment outcome. Results: The study included 775 patient records comprising 615 OPD and 160 hospitalised cases. Less than one-third (26.25%; 42) of the patients hospitalised were vaccinated compared to almost 40.0% (39.02%; 240) of the patients seen at the OPD. Vaccinated individuals were nearly three times (aOR = 2.72, 95%CI:1.74-4.25) more likely to be managed on an outpatient basis as compared to the unvaccinated. The death rate among the vaccinated group and the unvaccinated were (0.71%; 2) and (3.45%; 17), respectively, with a significant reduction in the risk of dying among the vaccinated compared to the unvaccinated (aOR = 0.13, 95%CI: 0.028 0.554). Conclusions: Less than half of the in-patient and OPD patients were vaccinated. Mild infections, fewer days of hospitalisation, outpatient treatment and higher chances of survival were associated with being vaccinated against SARS-CoV-2. Prudent measures should be implemented to encourage the general public to take up SARS-CoV-2 vaccines. Funding: None declared.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Hospitalização , Humanos , COVID-19/prevenção & controle , COVID-19/epidemiologia , Gana/epidemiologia , Masculino , Feminino , Estudos Retrospectivos , Vacinas contra COVID-19/administração & dosagem , Pessoa de Meia-Idade , Adulto , Hospitalização/estatística & dados numéricos , Vacinação/estatística & dados numéricos , SARS-CoV-2 , Idoso , Tempo de Internação/estatística & dados numéricos , Adulto Jovem , Adolescente
11.
JCI Insight ; 7(5)2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35260532

RESUMO

Phosphopeptides derived from dysregulated protein phosphorylation in cancer cells can be processed and presented by MHC class I and class II molecules and, therefore, represent an untapped class of tumor-specific antigens that could be used as widely expressed "public" cancer neoantigens (NeoAgs). We generated a TCR mimic (TCRm) mAb, 6B1, specific for a phosphopeptide derived from insulin receptor substrate 2 (pIRS2) presented by HLA-A*02:01. The pIRS2 epitope's presentation by HLA-A*02:01 was confirmed by mass spectrometry. The TCRm 6B1 specifically bound to pIRS2/HLA-A2 complex on tumor cell lines that expressed pIRS2 in the context of HLA-A*02:01. Bispecific mAbs engaging CD3 of T cells were able to kill tumor cell lines in a pIRS2- and HLA-A*02:01-restricted manner. Structure modeling shows a prerequisite for an arginine or lysine at the first position to bind mAb. Therefore, 6B1 could recognize phosphopeptides derived from various phosphorylated proteins with similar amino acid compositions. This raised the possibility that a TCRm specific for the pIRS2/HLA-A2 complex could target a range of phosphopeptides presented by HLA-A*02:01 in various tumor cells. This is the first TCRm mAb to our knowledge targeting a phosphopeptide/MHC class I complex; the potential of this class of agents for clinical applications warrants further investigation.


Assuntos
Antígeno HLA-A2 , Fosfopeptídeos , Anticorpos Monoclonais/metabolismo , Proteínas Substratos do Receptor de Insulina/metabolismo , Fosfopeptídeos/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo
12.
Elife ; 112022 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-35234613

RESUMO

Human skin functions as a physical barrier, preventing the entry of foreign pathogens while also accommodating a myriad of commensal microorganisms. A key contributor to the skin landscape is the sebaceous gland. Mice devoid of sebocytes are prone to skin infection, yet our understanding of how sebocytes function in host defense is incomplete. Here, we show that the small proline-rich proteins, SPRR1 and SPRR2 are bactericidal in skin. SPRR1B and SPPR2A were induced in human sebocytes by exposure to the bacterial cell wall component lipopolysaccharide (LPS). Colonization of germ-free mice was insufficient to trigger increased SPRR expression in mouse skin, but LPS injected into mouse skin stimulated increased expression of the mouse SPRR orthologous genes, Sprr1a and Sprr2a, through activation of MYD88. Both mouse and human SPRR proteins displayed potent bactericidal activity against MRSA (methicillin-resistant Staphylococcus aureus), Pseudomonas aeruginosa, and skin commensals. Thus, Sprr1a-/-;Sprr2a-/- mice are more susceptible to MRSA and P. aeruginosa skin infection. Lastly, mechanistic studies demonstrate that SPRR proteins exert their bactericidal activity through binding and disruption of the bacterial membrane. Taken together, these findings provide insight into the regulation and antimicrobial function of SPRR proteins in skin and how the skin defends the host against systemic infection.


Assuntos
Proteínas Ricas em Prolina do Estrato Córneo , Staphylococcus aureus Resistente à Meticilina , Animais , Antibacterianos , Lipopolissacarídeos , Proteínas de Membrana/metabolismo , Camundongos , Prolina
13.
PLoS One ; 17(3): e0265534, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35298559

RESUMO

More effective treatments are needed for human papilloma virus (HPV)-induced cancers despite HPV virus vaccination. The oncogenic HPV protein targets are currently undruggable and intracellular and therefore there are no antibodies to these targets. Here we report the discovery of TCR mimic monoclonal antibodies (TCRm mAb) specific for the HPV E7 protein p11-19, YMLDLQPET, when presented on the cell surface in the context of HLA-A*02:01 by use of human phage display libraries. One of the mAbs, 3F8, was able to specifically mediate T cell- redirected cytotoxicity, in a bispecific T cell engager (BiTE) form. While further studies are required to assess the therapeutic potential of this approach, the study provided the proof of concept that TCRm mAb could be a therapeutic strategy for HPV-induced human cancers.


Assuntos
Antineoplásicos Imunológicos , Neoplasias , Proteínas Oncogênicas Virais , Infecções por Papillomavirus , Anticorpos Monoclonais , Epitopos , Antígenos HLA-A , Papillomavirus Humano 16 , Humanos , Neoplasias/tratamento farmacológico , Proteínas E7 de Papillomavirus , Infecções por Papillomavirus/tratamento farmacológico , Receptores de Antígenos de Linfócitos T
14.
Sci Transl Med ; 14(636): eabe8195, 2022 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-35294260

RESUMO

Most patients with non-small cell lung cancer (NSCLC) do not achieve durable clinical responses from immune checkpoint inhibitors, suggesting the existence of additional resistance mechanisms. Nicotinamide adenine dinucleotide (NAD)-induced cell death (NICD) of P2X7 receptor (P2X7R)-expressing T cells regulates immune homeostasis in inflamed tissues. This process is mediated by mono-adenosine 5'-diphosphate (ADP)-ribosyltransferases (ARTs). We found an association between membranous expression of ART1 on tumor cells and reduced CD8 T cell infiltration. Specifically, we observed a reduction in the P2X7R+ CD8 T cell subset in human lung adenocarcinomas. In vitro, P2X7R+ CD8 T cells were susceptible to ART1-mediated ADP-ribosylation and NICD, which was exacerbated upon blockade of the NAD+-degrading ADP-ribosyl cyclase CD38. Last, in murine NSCLC and melanoma models, we demonstrate that genetic and antibody-mediated ART1 inhibition slowed tumor growth in a CD8 T cell-dependent manner. This was associated with increased infiltration of activated P2X7R+CD8 T cells into tumors. In conclusion, we describe ART1-mediated NICD as a mechanism of immune resistance in NSCLC and provide preclinical evidence that antibody-mediated targeting of ART1 can improve tumor control, supporting pursuit of this approach in clinical studies.


Assuntos
ADP Ribose Transferases , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Subpopulações de Linfócitos T , ADP Ribose Transferases/genética , ADP Ribose Transferases/metabolismo , Difosfato de Adenosina , Animais , Carcinoma Pulmonar de Células não Pequenas/imunologia , Proteínas Ligadas por GPI/genética , Humanos , Neoplasias Pulmonares/imunologia , Camundongos
15.
Health Promot Pract ; 23(3): 432-444, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34549654

RESUMO

There are profound health inequities for agricultural workers. We sought to assess the literature on migrant and seasonal farmworker health with an eye toward health promotion interventions, special populations, use of community health workers (CHWs), and technology. We conducted a systematic mapping review by searching five databases in March 2021. Using quantitative content analysis after establishing interrater reliability, we coded titles and abstracts to assess 13 topics and six characteristics of the research such as its focus on health promotion, use of technology, and inclusion of CHWs. We identified 1,083 records. Just 8.2% of records described or evaluated a health promotion effort to intervene in farmworker well-being and even fewer (4.2%) examined unique populations of farmworkers such as indigenous farmworkers (n = 11) or sexual minority farmworkers (n = 1). A small body of literature focused on the role of CHWs or promotores most frequently described their role in implementing health interventions. The literature on farmworker health has gaps regarding health promotion interventions, special populations, and integration of CHWs into research projects. We offer suggestions to fill in identified gaps in the literature.


Assuntos
Fazendeiros , Migrantes , Agentes Comunitários de Saúde , Humanos , Reprodutibilidade dos Testes , Estações do Ano , Estados Unidos
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 267(Pt 2): 120588, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34782269

RESUMO

Fourier Transform Infra-Red (FTIR) spectroscopy provides structural information of prime importance to understand ions coordination to adsorbents. This consequently aids in the design of improved ion exchange materials and help in deriving the optimum adsorption conditions. In the present work, the adsorption mechanism of both U(VI)/Th(IV) and Ra(II)/Ba(II) radionuclides couples onto polystyrene-nano manganese dioxide (PS-NMO) composite is reported in relation to the effect of working solution pH. The separation of each radionuclide couple; i.e. U(VI)/Th(IV) and Ra(II)/Ba(II); could be effectively achieved at pH = 3 and pH = 1 respectively. The pH values not only determine the species of the respected elements that are mainly present in aqueous solution before applying the adsorbent, but it also alters the structure of the composite adsorbent. FTIR spectroscopy showed that Th(IV) formed inner sphere complexes and occupied the A site in the dioxide layer, while U(VI) formed outer sphere complexes on the surface of the composite. Spectra subtraction showed that some aromatic bands and vinyl C-H bands were split or shifted to lower wavenumbers with the loading of Ba(II). This was attributed to changes in the composite stereochemistry to accommodate Ba(II). The working solution pH could be the key in the separation process of both U(VI)/Th(IV) and Ra(II)/Ba(II) from their mixture, and FTIR spectroscopy stands as a useful technique to explain the difference between metal ions responses to adsorbants.


Assuntos
Poliestirenos , Urânio , Adsorção , Análise de Fourier , Concentração de Íons de Hidrogênio , Espectroscopia de Infravermelho com Transformada de Fourier
17.
Exp Hematol ; 105: 50-61, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34757171

RESUMO

Diamond-Blackfan anemia (DBA) is a rare genetic disorder in which patients present a scarcity of erythroid precursors in an otherwise normocellular bone marrow. Most, but not all, patients carry mutations in ribosomal proteins such as RPS19, suggesting that compromised mRNA translation and ribosomal stress are pathogenic mechanisms causing depletion of erythroid precursors. To gain further insight to disease mechanisms in DBA, we performed a custom short hairpin RNA (shRNA) based screen against 750 genes hypothesized to affect DBA pathophysiology. Among the hits were two shRNAs against the erythroid specific heme-regulated eIF2α kinase (HRI), which is a negative regulator of mRNA translation. This study shows that shRNA-mediated HRI silencing or loss of one HRI allele improves expansion of Rps19-deficient erythroid precursors, as well as improves the anemic phenotype in Rps19-deficient animals. We found that Rps19-deficient erythroblasts have elevated levels of unbound intracellular heme, which is normalized by HRI heterozygosity. Additionally, targeting elevated heme levels by treating cells with the heme scavenger alpha-1-microglobulin (A1M), increased proliferation of Rps19-deficient erythroid precursors and decreased heme levels in a disease-specific manner. HRI heterozygosity, but not A1M treatment, also decreased the elevated p53 activity observed in Rps19-deficient cells, indicating that p53 activation is caused by ribosomal stress and aberrant mRNA translation and not heme overload in Rps19-deficiency. Together, these findings suggest that targeting elevated heme levels is a promising new treatment strategy for DBA.


Assuntos
alfa-Globulinas/uso terapêutico , Anemia de Diamond-Blackfan/terapia , Heme/análise , Anemia de Diamond-Blackfan/sangue , Anemia de Diamond-Blackfan/genética , Animais , Células Cultivadas , Modelos Animais de Doenças , Feminino , Deleção de Genes , Inativação Gênica , Terapia Genética , Heme/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Serina-Treonina Quinases/genética , Proteínas Recombinantes/uso terapêutico , Proteínas Ribossômicas/genética
18.
Nat Commun ; 12(1): 4611, 2021 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-34326333

RESUMO

Hedgehog signaling is essential for bone formation, including functioning as a means for the growth plate to drive skeletal mineralization. However, the mechanisms regulating hedgehog signaling specifically in bone-forming osteoblasts are largely unknown. Here, we identified SLIT and NTRK-like protein-5(Slitrk5), a transmembrane protein with few identified functions, as a negative regulator of hedgehog signaling in osteoblasts. Slitrk5 is selectively expressed in osteoblasts and loss of Slitrk5 enhanced osteoblast differentiation in vitro and in vivo. Loss of SLITRK5 in vitro leads to increased hedgehog signaling and overexpression of SLITRK5 in osteoblasts inhibits the induction of targets downstream of hedgehog signaling. Mechanistically, SLITRK5 binds to hedgehog ligands via its extracellular domain and interacts with PTCH1 via its intracellular domain. SLITRK5 is present in the primary cilium, and loss of SLITRK5 enhances SMO ciliary enrichment upon SHH stimulation. Thus, SLITRK5 is a negative regulator of hedgehog signaling in osteoblasts that may be attractive as a therapeutic target to enhance bone formation.


Assuntos
Cílios/metabolismo , Proteínas Hedgehog/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Osteoblastos/metabolismo , Osteogênese/fisiologia , Receptor Patched-1/metabolismo , Animais , Diferenciação Celular , Células Cultivadas , Proteínas Hedgehog/genética , Humanos , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Osteoblastos/citologia , Receptor Patched-1/genética , Transdução de Sinais
19.
Heliyon ; 7(6): e07306, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34189327

RESUMO

Proton irradiated poly (ether ether ketone) (PEEK) films were crystallized to different extents, and subsequently characterized by wide angle X-ray diffraction technique. The data were analyzed by two-dimensional correlation mapping (2D-CM), in particular: Generalized, hybrid and multiple perturbations correlation approaches. Two asynchronous correlation peaks at (19.1, 18.7) o and at (22.5, 19.1) o were utilized as a measure the crystal perfection and the preferred process; orientation/crystal growth respectively. Proton irradiation not only favored the formation of crystal form II, but also changed the type of orientation within the irradiated films. Differential scanning calorimetry and Raman spectroscopic analysis confirmed the contribution of the previous two factors. Raman spectra indicated that the intensity of both bands at 1595 and 1608 cm-1 decreased on samples crystallized from the melt, but increased on cold crystallized samples. 2D-CM combined with other suitable techniques is a promising in evaluating the structure of polymers and revealing the effect of proton irradiation.

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