RESUMO
Motional narrowing implies narrowing induced by motion; for example, in nuclear magnetic resonance, the thermally induced random motion of the nuclei in an inhomogeneous environment leads to a counterintuitive narrowing of the resonance line. Similarly, the excitons in monolayer semiconductors experience magnetic inhomogeneity: the electron-hole spin-exchange interaction manifests as an in-plane pseudomagnetic field with a periodically varying orientation inside the exciton band. The excitons undergo random momentum scattering and pseudospin precession repeatedly in this inhomogeneous magnetic environment, typically resulting in fast exciton depolarization. On the contrary, we show that such magnetic inhomogeneity averages out at high scattering rates due to motional narrowing. Physically, a faster exciton scattering leads to a narrower pseudospin distribution on the Bloch sphere, implying a nontrivial improvement in exciton polarization. The in-plane nature of the pseudomagnetic field enforces a contrasting scattering dependence between the circularly and linearly polarized excitons, providing a spectroscopic way to gauge the sample quality.
RESUMO
Honeybees are vital for global crop pollination, making indispensable contributions to agricultural productivity. However, these vital insects are currently facing escalating colony losses on a global scale, primarily attributed to parasitic and pathogenic attacks. The prevalent response to combat these infections may involve the use of antibiotics. Nevertheless, the application of antibiotics raises concerns regarding potential adverse effects such as antibiotic resistance and imbalances in the gut microbiota of bees. In response to these challenges, this study reviews the utilization of a probiotic-supplemented pollen substitute diet to promote honeybee gut health, enhance immunity, and overall well-being. We systematically explore various probiotic strains and their impacts on critical parameters, including survival rate, colony strength, honey and royal jelly production, and the immune response of bees. By doing so, we emphasize the significance of maintaining a balanced gut microbial community in honeybees. The review also scrutinizes the factors influencing the gut microbial communities of bees, elucidates the consequences of dysbiosis, and evaluates the potential of probiotics to mitigate these challenges. Additionally, it delineates different delivery mechanisms for probiotic supplementation and elucidates their positive effects on diverse health parameters of honeybees. Given the alarming decline in honeybee populations and the consequential threat to global food security, this study provides valuable insights into sustainable practices aimed at supporting honeybee populations and enhancing agricultural productivity.
Assuntos
Criação de Abelhas , Probióticos , Abelhas , Animais , Agricultura , Antibacterianos , DisbioseRESUMO
Mucinous differentiation of the endometrium can occur in a spectrum of changes ranging from benign (metaplasia) to malignant (adenocarcinomas with mucinous differentiation). A rarer differential which is usually not considered is a teratoma. We present a case of a 55-yr-old woman with history of irregular perimenopausal bleeding. Endometrial curetting revealed proliferative mucinous epithelium on histology raising a possibility of low-grade epithelial mucinous malignancy. Hysterectomy was performed and histologic examination revealed a diagnosis of uterine mature teratoma. Mature cystic teratoma of the lower uterine segment is very rare and presence of just one element such as mucinous epithelium can lead to a misdiagnosis of carcinoma on biopsy or curetting.
Assuntos
Endométrio , Teratoma , Endométrio/patologia , Endométrio/cirurgia , Epitélio/patologia , Feminino , Humanos , Histerectomia , Teratoma/patologia , Útero/patologiaRESUMO
Fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) are the primary catabolic enzymes for endocannabinoids, anandamide (AEA), and 2-arachidonoyl glycerol. Numerous studies have shown that FAAH and MAGL play an important role in modulating various central nervous system activities; hence, the development of small molecule FAAH/MAGL inhibitors is an active area of research. Several small molecules possessing the carbamate scaffold are documented as potential FAAH/MAGL inhibitors. Here, we designed and synthesized a series of open chain and cyclic carbamates and evaluated their dual FAAH-MAGL inhibition properties. Phenyl [4-(piperidin-1-ylmethyl)phenyl]carbamate (2e) emerged as the most potent MAGL inhibitor (IC50 = 19 nM), benzyl (1H-benzo[d]imidazol-2-yl)carbamate (3h) was the most potent FAAH inhibitor (IC50 = 55 nM), and phenyl (6-fluorobenzo[d]thiazol-2-yl)carbamate (2i) egressed as a nonselective dual FAAH-MAGL inhibitor (FAAH: 82 nM, MAGL: 72 nM). The enzyme kinetics experiments revealed that the compounds inhibit FAAH/MAGL in a covalent-reversible manner, with a mixed binding mode of action. Moreover, the lead compounds were found suitable for blood-brain permeation in the parallel artificial membrane permeation assay. Furthermore, docking simulation experiments suggested that the potency of the lead compounds was governed by hydrogen bonds and hydrophobic interactions with the enzyme active sites. In silico drug-likeness and ADMETox prediction studies provided useful information on the compounds' oral absorption, metabolism, and toxicity profiles. In summary, this study afforded potent multifunctional carbamates with appreciable pharmacokinetic profiles meriting further investigation.
Assuntos
Carbamatos , Monoacilglicerol Lipases , Monoacilglicerol Lipases/metabolismo , Monoglicerídeos , Relação Estrutura-Atividade , Inibidores Enzimáticos , AmidoidrolasesRESUMO
Human ADAMTS13 is a multidomain protein with metalloprotease (M), disintegrin-like (D), thrombospondin-1 (T), Cys-rich (C), and spacer (S) domains, followed by 7 additional T domains and 2 CUB (complement components C1r and C1s, sea urchin protein Uegf, and bone morphogenetic protein-1) domains. ADAMTS13 inhibits the growth of von Willebrand factor (VWF)-platelet aggregates by cleaving the cryptic Tyr1605-Met1606 bond in the VWF A2 domain. ADAMTS13 is regulated by substrate-induced allosteric activation; without shear stress, the distal T8-CUB domains markedly inhibit VWF cleavage, and binding of VWF domain D4 or selected monoclonal antibodies (MAbs) to distal ADAMTS13 domains relieves this autoinhibition. By small angle X-ray scattering (SAXS), ADAMTS13 adopts a hairpin-like conformation with distal T7-CUB domains close to the proximal MDTCS domains and a hinge point between T4 and T5. The hairpin projects like a handle away from the core MDTCS and T7-CUB complex and contains distal T domains that are dispensable for allosteric regulation. Truncated constructs that lack the T8-CUB domains are not autoinhibited and cannot be activated by VWF D4 but retain the hairpin fold. Allosteric activation by VWF D4 requires T7, T8, and the 58-amino acid residue linker between T8 and CUB1. Deletion of T3 to T6 produced the smallest construct (delT3-6) examined that could be activated by MAbs and VWF D4. Columba livia (pigeon) ADAMTS13 (pADAMTS13) resembles human delT3-6, retains normal activation by VWF D4, and has a SAXS envelope consistent with amputation of the hairpin containing the dispensable T domains of human ADAMTS13. Our findings suggest that human delT3-6 and pADAMTS13 approach a "minimal" structure for allosterically regulated ADAMTS13.
Assuntos
Proteína ADAMTS13/química , Proteína ADAMTS13/metabolismo , Mutação , Estrutura Terciária de Proteína , Espalhamento a Baixo Ângulo , Fator de von Willebrand/metabolismo , Proteína ADAMTS13/genética , Regulação Alostérica , Sítios de Ligação , Domínio Catalítico , Humanos , Modelos Moleculares , Mutagênese , Ligação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
The metalloprotease ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 repeats member 13) prevents microvascular thrombosis by cleaving von Willebrand factor (VWF) within platelet-rich thrombi, and cleavage depends on allosteric activation of ADAMTS13 by the substrate VWF. Human ADAMTS13 has a short propeptide, metalloprotease (M), disintegrin-like (D), thrombospondin-1 (T), Cys-rich (C), and spacer (S) domains (proximal domains), followed by 7 T and 2 CUB (complement components C1r and C1s, sea urchin protein Uegf, and bone morphogenetic protein-1) domains (distal domains). Distal domains inhibit the catalytic proximal domains; binding of distal T8-CUB domains to the VWF D4 domain relieves autoinhibition and promotes cleavage of the nearby VWF A2 domain. However, the role of specific ADAMTS13 distal domains in this allosteric mechanism is not established. Assays of plasma ADAMTS13 from 20 placental mammals, birds, and amphibians show that allosteric regulation is broadly conserved, and phylogenetic analysis of 264 vertebrates shows the long propeptide, T3, T4, T6, and T6a domains have been deleted several times in placental mammals, birds, and fish. Notably, pigeon ADAMTS13 has only 3 distal T domains but was activated normally by human VWF D4 and cleaved VWF multimers, preferentially under fluid shear stress. Human ADAMTS13 constructed to resemble pigeon ADAMTS13 retained normal allosteric regulation and shear-dependent cleavage of VWF. Thus, the T3-T6 domains of human ADAMTS13 are dispensable. Conversely, deletion of T7 or T8 abolished allosteric activation. For most species, some sequence changes in the VWF substrate can markedly increase the rate of cleavage, suggesting that ADAMTS13 and VWF have not evolved to be optimal enzyme-substrate pairs. These properties may reflect evolutionary pressure to balance the risk for VWF-dependent bleeding and thrombosis.
Assuntos
Proteína ADAMTS13/metabolismo , Evolução Molecular , Filogenia , Proteínas Recombinantes/metabolismo , Fator de von Willebrand/metabolismo , Regulação Alostérica , Sequência de Aminoácidos , Animais , Domínio Catalítico , Humanos , Ligação Proteica , Homologia de Sequência , Especificidade por SubstratoRESUMO
BACKGROUND: Intracerebral hemorrhage (ICH) is associated with high mortality, morbidity, and recurrence. Studies have reported the accuracy of several blood biomarkers in predicting clinical outcomes; however, their independent contribution in prediction remains to be established. AIM: To investigate the incremental accuracy in predicting clinical outcomes in patients with ICH in a north Indian population using blood-based biomarkers. METHODS: In this study, a total of 250 ICH cases were recruited within 72 hours of onset. Baseline clinical and CT scan measurement were recorded. Homocysteine (HCY), C-reactive protein (CRP), matrix metalloproteinase-9 (MMP9), E-selectin (SELE), and P-selectin (SELP) levels were measured through ELISA. Telephonic follow-up was done by using mRS scale at three months. RESULTS: The mean age of cohort was 54.9 (SD±12.8) years with 64.8% patients being male. A total of 109 (43.6%) deaths were observed over three months follow-up. Area under the receiver operating characteristics curve-(AUROC) for 90-day mortality were 0.55 (HCY), 0.62 (CRP), 0.57 (MMP9), 0.60 (SELE) and 0.53 (SELP) and for poor outcome at 90-day (mRS: 3-6) were 0.60 (HCY), 0.62 (CRP), 0.54 (MMP9), 0.67 (SELE) and 0.54 (SELP). In multivariable model including age, ICH volume, IVH and GCS at admission, serum SELE (p=0.004) significant for poor outcome with improved AUROC (0.86) and HCY (p=0.04), CRP (p=0.003) & MMP9 (p=0.02) for mortality with least Akaike's Information Criterion-(AIC) (1060.5). CONCLUSIONS: Our findings suggest that the serum SELE is a significant predictor of poor outcome and HCY, CRP & MMP9 for Mortality in patients with ICH in the north Indian population.
Assuntos
Proteína C-Reativa/análise , Hemorragia Cerebral/sangue , Selectina E/sangue , Homocisteína/sangue , Metaloproteinase 9 da Matriz/sangue , Adulto , Idoso , Biomarcadores/sangue , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/mortalidade , Hemorragia Cerebral/cirurgia , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
Human brown adipose tissue (BAT) can be activated to increase glucose uptake and energy expenditure, making it a potential target for treating obesity and metabolic disease. Data on the functional and anatomic characteristics of BAT are limited, however. In 20 healthy young men [12 lean, mean body mass index (BMI) 23.2 ± 1.9 kg/m2; 8 obese, BMI 34.8 ± 3.3 kg/m2] after 5 h of tolerable cold exposure, we measured BAT volume and activity by 18F-labeled fluorodeoxyglucose positron emission tomography/computerized tomography (PET/CT). Obese men had less activated BAT than lean men (mean, 130 vs. 334 mL) but more fat in BAT-containing depots (mean, 1,646 vs. 855 mL) with a wide range (0.1-71%) in the ratio of activated BAT to inactive fat between individuals. Six anatomic regions had activated BAT-cervical, supraclavicular, axillary, mediastinal, paraspinal, and abdominal-with 67 ± 20% of all activated BAT concentrated in a continuous fascial layer comprising the first three depots in the upper torso. These nonsubcutaneous fat depots amounted to 1.5% of total body mass (4.3% of total fat mass), and up to 90% of each depot could be activated BAT. The amount and activity of BAT was significantly influenced by region of interest selection methods, PET threshold criteria, and PET resolutions. The present study suggests that active BAT can be found in specific adipose depots in adult humans, but less than one-half of the fat in these depots is stimulated by acute cold exposure, demonstrating a previously underappreciated thermogenic potential.
Assuntos
Tecido Adiposo Marrom/diagnóstico por imagem , Adiposidade , Índice de Massa Corporal , Obesidade/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Tecido Adiposo Marrom/metabolismo , Adulto , Glucose-6-Fosfato/administração & dosagem , Glucose-6-Fosfato/análogos & derivados , Humanos , Masculino , Obesidade/metabolismoRESUMO
Priapism is an uncommon presentation in children and adults with a chronic myeloid type of leukemia. Its association is rarely found in an acute lymphoblastic type of leukemia (ALL). Timely management is important to prevent irreversible complications. We report a case of ALL with presenting complaint of priapism.
RESUMO
BACKGROUND: Somatic mutations in hypoxia-inducible factor 2α (HIF2A) are associated with polycythemia-paraganglioma syndrome. Specifically, the classic presentation of female patients with recurrent paragangliomas (PGLs), polycythemia (at birth or in early childhood), and duodenal somatostatinomas has been described. Studies have demonstrated that somatic HIF2A mutations occur as postzygotic events and some to be associated with somatic mosaicism affecting hematopoietic and other tissue precursors. This phenomenon could explain the development of early onset of polycythemia in the absence of erythropoietin-secreting tumors. METHODS: Correlation analysis was performed between mosaicism of HIF2A mutant patients and clinical presentations. RESULTS: Somatic HIF2A mutations (p.A530V, p.P531S, and p.D539N) were identified in DNA extracted from PGLs of 3 patients. No somatic mosaicism was detected through deep sequencing of blood genomic DNA. Compared with classic syndrome, both polycythemia and PGL in all 3 patients developed at an advanced age with polycythemia at age 30, 30, and 17 years and PGLs at age 34, 30, and 55 years, respectively. Somatostatinomas were not detected, and 2 patients had ophthalmic findings. The biochemical phenotype in all 3 patients was noradrenergic with 18 F-fluorodopa PET/CT as the most sensitive imaging modality. All patients demonstrated multiplicity, and none developed metastatic disease. CONCLUSION: These findings suggest that newer techniques need to be developed to detect somatic mosaicism in patients with this syndrome. Absence of HIF2A mosaicism in patients with somatic HIF2A mutations supports association with late onset of the disease, milder clinical phenotype, and an improved prognosis compared with patients who have HIF2A mosaicism.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Paraganglioma/classificação , Mutação Puntual , Policitemia/classificação , Adolescente , Adulto , Idade de Início , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Pessoa de Meia-Idade , Mosaicismo , Paraganglioma/diagnóstico por imagem , Paraganglioma/genética , Policitemia/diagnóstico por imagem , Policitemia/genética , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Análise de Sequência de DNARESUMO
PURPOSE: To evaluate and compare diagnostic performance of 68Ga-DOTA(0)-Tyr(3)-octreotate (68Ga-DOTATATE) with 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography-computed tomography (PET/CT) and anatomic imaging using computed tomography and/or magnetic resonance (CT/MR) imaging in detection of SDHx-related pheochromocytomas and paragangliomas (PPGLs) in pediatric patients. METHODS: Nine pediatric patients (5:4, girls:boys; 14.6 ± 2.0 years) with an SDHx-related mutation (SDHB:SDHA:SDHD, n = 7:1:1) were included in this retrospective study. At the time of initial diagnosis, 7/9 patients had metastatic disease. They underwent CT/MR imaging along with PET/CT using 68Ga-DOTATATE (n = 9), 18F-FDG (n = 8), and positron emission tomography-magnetic resonance imaging (PET/MR) using 18F-FDG (n = 1). In this manuscript, 18F-FDG PET/CT refers to both 18F-FDG PET/CT and 18F-FDG PET/MR. The per-lesion, per-region, and per-patient detection rates were compared and calculated for each of the imaging modalities. A composite of all functional and anatomic imaging studies served as the imaging comparator. RESULTS: Eight out of nine patients were positive for PPGLs on the imaging studies that demonstrated 107 lesions in 22 anatomic regions on the imaging comparator. The per-lesion detection rates for 68Ga-DOTATATE PET/CT, 18F-FDG PET/CT, and CT/MR imaging were 93.5% (95%CI, 87.0% to 97.3%); 79.4% (95%CI, 70.5% to 86.6%); and 73.8% (95%CI, 64.5% to 81.9%), respectively. The per-lesion detection rate for 68Ga-DOTATATE PET/CT was significantly higher than that of 18F-FDG PET/CT (p = 0.001) or CT/MR imaging (p < 0.001). In all of the anatomic regions except abdomen, the per-lesion detection rates for 68Ga-DOTATATE PET/CT was found to be equal or superior to 18F-FDG PET/CT, and CT/MR imaging. The per-region detection rate was 100% (95%CI, 84.6% to 100%) for 68Ga-DOTATATE PET/CT and 90.9% (95%CI, 70.8% to 98.9%) for both 18F-FDG PET/CT and CT/MR imaging. The per-patient detection rates for 68Ga-DOTATATE PET/CT, 18FDG PET/CT, and CT/MR imaging were all 100% (95%CI, 63.1% to 100%). CONCLUSION: Our preliminary study demonstrates the superiority of 68Ga-DOTATATE PET/CT in localization of SDHx-related PPGLs in pediatric population compared to 18F-FDG PET/CT and CT/MR imaging with the exception of abdominal (excluding adrenal and liver) lesions, and suggests that it might be considered as a first-line imaging modality in pediatric patients with SDHx-related PPGLs.
Assuntos
Mutação , Compostos Organometálicos , Paraganglioma/genética , Feocromocitoma/genética , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Succinato Desidrogenase/genética , Adolescente , Criança , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Paraganglioma/diagnóstico por imagem , Feocromocitoma/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Estudos Retrospectivos , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: The role of the hypoxia signaling pathway in the pathogenesis of pheochromocytoma/paraganglioma (PPGL)-polycythemia syndrome has been elucidated. Novel somatic mutations in hypoxia-inducible factor type 2A (HIF2A) and germline mutations in prolyl hydroxylase type 1 and type 2 (PHD1 and PHD2) have been identified to cause upregulation of the hypoxia signaling pathway and its target genes including erythropoietin (EPO) and its receptor (EPOR). However, in a minority of patients presenting with this syndrome, the genetics and molecular pathogenesis remain unexplained. The aim of the present study was to uncover novel genetic causes of PPGL-polycythemia syndrome. CASE PRESENTATION: A female presented with a history of JAK2V617F positive PV, diagnosed in 2007, and right adrenal pheochromocytoma diagnosed and resected in 2011. Her polycythemia symptoms and hematocrit levels continued to worsen from 2007 to 2011, with an increased frequency of phlebotomies. Postoperatively, until early 2013, her hematocrit levels remained normalized. Following this, the hematocrit levels ranged between 46.4 and 48.9% [35-45%]. Tumor tissue from the patient was further tested for mutations in genes related to upregulation of the hypoxia signaling pathway including iron regulatory protein 1 (IRP1), which is a known regulator of HIF-2α mRNA translation. Functional studies were performed to investigate the consequences of these mutations, especially their effect on the HIF signaling pathway and EPO. Indel mutations (c.267-1_267delGGinsTA) were discovered at the exon 3 splicing site of IRP1. Minigene construct and splicing site analysis showed that the mutation led to a new splicing site and a frameshift mutation of IRP1, which caused a truncated protein. Fluorescence in situ hybridization analysis demonstrated heterozygous IRP1 deletions in tumor cells. Immunohistochemistry results confirmed the truncated IRP1 and overexpressed HIF-2α, EPO and EPOR in tumor cells. CONCLUSIONS: This is the first report which provides direct molecular genetic evidence of association between a somatic IRP1 loss-of-function mutation and PHEO and secondary polycythemia. In patients diagnosed with PHEO/PGL and polycythemia with negative genetic testing for mutations in HIF2A, PHD1/2, and VHL, IRP1 should be considered as a candidate gene.
Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Mutação em Linhagem Germinativa , Proteína 1 Reguladora do Ferro/genética , Janus Quinase 2/genética , Feocromocitoma/genética , Policitemia Vera/genética , Splicing de RNA , Neoplasias das Glândulas Suprarrenais/complicações , Neoplasias das Glândulas Suprarrenais/patologia , Adulto , Feminino , Humanos , Feocromocitoma/complicações , Feocromocitoma/patologia , Policitemia Vera/complicações , Policitemia Vera/patologia , PrognósticoRESUMO
OBJECTIVE: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors known to produce and secrete high levels of circulating catecholamines and their metabolites. The biochemical characteristics of these tumors can be used to divide them into three major phenotypes. The adrenergic, noradrenergic and dopaminergic phenotypes are defined by predominant elevations in epinephrine and metanephrine, norepinephrine and normetanephrine, and dopamine and 3-methoxytyramine, respectively. There are over 15 well-identified tumor-susceptibility genes responsible for approximately 40% of the cases. The objective of this review article is to outline specific genotype/biochemical phenotype relationships. METHODS: Literature review. RESULTS: None. CONCLUSION: Biochemical phenotype of PPGL is determined by the underlying genetic mutation and the associated molecular pathway. Identification of genotype/biochemical relationships is valuable in prioritizing testing for specific genes, making treatment decisions and monitoring disease progression. ABBREVIATIONS: 3-MT = 3-methoxytyramine; EPAS1 = endothelial pas domain protein 1; FH = fumarate hydratase; HIF2A = hypoxia inducible factor type 2A; MEN2 = multiple endocrine neoplasia type 2; NF1 = neurofibromatosis type 1; PNMT = phenylethanolamine N-methyltransferase; PPGL = pheochromocytoma and paraganglioma; RET = rearranged during transfection; SDH = succinate dehydrogenase; SDHAF2 = succinate dehydrogenase complex assembly factor 2; TCA = tricarboxylic acid; TH = tyrosine hydroxylase; TMEM127 = transmembrane protein 127; VHL = von Hippel-Lindau.
Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Feocromocitoma/genética , Neoplasias das Glândulas Suprarrenais/metabolismo , Dopamina/metabolismo , Epinefrina/metabolismo , Genótipo , Humanos , Norepinefrina/metabolismo , Paraganglioma/genética , Paraganglioma/metabolismo , Fenótipo , Feocromocitoma/metabolismo , Medicina de PrecisãoRESUMO
The metalloprotease ADAMTS13 cleaves von Willebrand factor (VWF) within endovascular platelet aggregates, and ADAMTS13 deficiency causes fatal microvascular thrombosis. The proximal metalloprotease (M), disintegrin-like (D), thrombospondin-1 (T), Cys-rich (C), and spacer (S) domains of ADAMTS13 recognize a cryptic site in VWF that is exposed by tensile force. Another seven T and two complement C1r/C1s, sea urchin epidermal growth factor, and bone morphogenetic protein (CUB) domains of uncertain function are C-terminal to the MDTCS domains. We find that the distal T8-CUB2 domains markedly inhibit substrate cleavage, and binding of VWF or monoclonal antibodies to distal ADAMTS13 domains relieves this autoinhibition. Small angle X-ray scattering data indicate that distal T-CUB domains interact with proximal MDTCS domains. Thus, ADAMTS13 is regulated by substrate-induced allosteric activation, which may optimize VWF cleavage under fluid shear stress in vivo. Distal domains of other ADAMTS proteases may have similar allosteric properties.
Assuntos
Proteínas ADAM/química , Fator de von Willebrand/química , Proteínas ADAM/sangue , Proteínas ADAM/genética , Proteína ADAMTS13 , Regulação Alostérica/fisiologia , Ativação Enzimática/fisiologia , Humanos , Ligação Proteica , Estrutura Quaternária de Proteína , Estrutura Terciária de Proteína , Fator de von Willebrand/genética , Fator de von Willebrand/metabolismoRESUMO
We report herein the design and synthesis of bioisosteres of spirooxindole (MI-63/219), a small-molecule inhibitors of the MDM2-p53 interaction as anti-breast cancer agents. Compound 5b has been exhibiting significant anti-proliferative activity in nude mice bearing MCF-7 xenograft tumor. The compound 5b was found to act via modulation of MDM2 and p53 expression in breast cancer cells expressing wild type p53. Compound 5b stimulated p53 activation, caused modulation of downstream effectors p21, pRb, and cyclin D1 which regulate cell cycle. Thus, compound triggered G1-S phase cell cycle arrest, which was evident by flow cytometric analysis of treated breast cancer cells. Thus, compound 5b restores the p53 function, which triggers molecular events consistent with cell cycle arrest at G1/S phase.
Assuntos
Antineoplásicos/química , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Indóis/química , Indóis/uso terapêutico , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Antineoplásicos/farmacologia , Mama/efeitos dos fármacos , Mama/metabolismo , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Desenho de Fármacos , Feminino , Humanos , Indóis/farmacologia , Camundongos Nus , Oxindóis , Mapas de Interação de Proteínas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Compostos de Espiro/uso terapêutico , Proteína Supressora de Tumor p53/antagonistas & inibidoresRESUMO
A novel series of pyrazole derivatives were synthesized and evaluated in vivo for their anti-inflammatory activity in carrageenan-induced rat paw edema model. Among all compounds, 5a, and 5b showed comparable anti-inflammatory activity to Nimesulide, the standard drug taken for the studies. In silico (docking) studies were carried out to investigate the theoretical binding mode of the compounds to target the cyclooxygenase (COX-2) using Autodock 4.2.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Inibidores de Ciclo-Oxigenase/farmacologia , Edema/tratamento farmacológico , Pirazóis/farmacologia , Animais , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase/síntese química , Inibidores de Ciclo-Oxigenase/química , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Pirazóis/síntese química , Pirazóis/química , Ratos , Ratos Wistar , Relação Estrutura-AtividadeRESUMO
The current study introduces an innovative methodology by utilizing treated wastewater (TWW) from an effluent treatment plant as a washing agent to enhance the characteristics of incineration bottom ash (IBA). This approach addresses sustainability concerns and promotes the circular economy by reusing wastewater generated in municipal solid waste incineration facilities. Previous research has underscored the challenges of open IBA reuse due to elevated leaching of chlorides, sulfates, and trace metal(loid)s. Thus, the experimental setup explores various combinations of washing, with or without screening, to optimize the properties of soil-like material (SLM < 4.75 mm) and overall material (OM < 31.5 mm) fractions of IBA for unrestricted applications. Batch leaching tests were conducted on treated samples, and leaching characteristics were evaluated in accordance with regulatory standards, primarily the Dutch standard for unrestricted IBA reuse. The findings reveal that washing in isolation proves insufficient to enhance IBA properties; however, washing followed by screening, specifically for removing fines (<0.15 mm), proves effective in reducing contamination. The study identifies that multiple steps of washing and screening (with recirculation) process render OM and SLM fractions suitable for unrestricted reuse with a cumulative liquid-to-solid ratio of 6 L/kg and a total washing time of 15 min. The multi-step treatment was found effective in reducing sulfate contamination by 65-74 % and chloride contamination by 83-89 % in IBA fractions. This approach offers a promising solution for overcoming the limitations associated with IBA leaching, thereby promoting sustainable waste reuse practices.
Assuntos
Incineração , Águas Residuárias , Incineração/métodos , Águas Residuárias/química , Resíduos Sólidos/análise , Reciclagem/métodos , Cinza de Carvão/análise , Cinza de Carvão/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análiseRESUMO
Monoclonal gammopathy of uncertain significance associated acquired von Willebrand syndrome is a serious bleeding condition driven by immunological clearance of von Willebrand factor and has limited treatment options. We present a patient who achieved durable remission through eradication of the monoclonal paraprotein with clonal directed therapy with bortezomib.
RESUMO
Conventional systemic cancer therapy often causes numerous adverse events. However, discovering overexpressed folate receptors in solid tumors has paved the way for targeted chemotherapy. Folic acid (FA), a ligand for these receptors, is frequently combined with chemotherapeutic drugs to improve their effectiveness. Carbon nanotubes have emerged as a versatile and promising method for delivering these folate-conjugated nano-systems, ensuring targeted delivery of therapeutic agents to cancerous cells. When FA-conjugated nanotubes dissociate, they release the drug-loaded nanotubes inside the malignant cells, reducing off-target effects. These nanotubes can also be used for combination therapies, producing synergistic effects. This review aims to comprehensively gather and critically evaluate the latest methods for delivering therapeutics using FA-conjugated nanovehicles. Additionally, it seeks to enhance our comprehension of the pertinent chemistry and biochemical pathways involved in this approach.