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1.
BMJ Case Rep ; 17(7)2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38960417

RESUMO

Sjogren's syndrome is a known cause of renal tubular acidosis (RTA). However, osteomalacia associated with Sjogren's syndrome is rare and seldom reported in literature. We report a case of pseudofractures of both femora due to osteomalacia as a result of RTA secondary to Sjogren's syndrome, which was initially misdiagnosed as a stress fracture. A man in his 30s presented with hip pain and was initially misdiagnosed to have stress fractures because of the 'through and through' extension of the 'fracture' lines at the neck of both femora. The patient had a normal serum biochemistry profile except for elevated alkaline phosphatase levels. On further evaluation, he was found to have distal RTA secondary to Sjogren's syndrome. The patient responded to sodium bicarbonate therapy with clinical, biochemical and radiological improvement. A high index of suspicion for RTA should be kept in a patient with osteomalacia with a normal calcium profile and vitamin D level.


Assuntos
Osteomalacia , Síndrome de Sjogren , Humanos , Síndrome de Sjogren/complicações , Síndrome de Sjogren/diagnóstico , Masculino , Osteomalacia/etiologia , Osteomalacia/diagnóstico , Adulto , Acidose Tubular Renal/diagnóstico , Acidose Tubular Renal/etiologia , Acidose Tubular Renal/complicações , Diagnóstico Diferencial , Fraturas de Estresse/etiologia , Fraturas de Estresse/diagnóstico por imagem , Fraturas de Estresse/diagnóstico , Bicarbonato de Sódio/uso terapêutico
2.
ACS Appl Mater Interfaces ; 16(30): 40210-40221, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39037739

RESUMO

Chalcogenide perovskites exhibit optoelectronic properties that position them as potential materials in the field of photovoltaics. We report a detailed investigation into the electronic structure and chemical properties of polycrystalline BaZrS3 perovskite powder by X-ray photoelectron spectroscopy, complemented by an analysis of its long- and short-range geometric structures using X-ray diffraction and X-ray absorption spectroscopy. The results obtained for the powdered BaZrS3 are compared to similar measurements on a sputtered polycrystalline BaZrS3 thin film prepared through rapid thermal processing. While bulk characterization confirms the good quality of the powder, depth-profiling achieved by photoelectron spectroscopy utilizing Al Kα (1.487 keV) and Ga Kα (9.25 keV) radiations shows that, regardless of the fabrication method, the oxidation effects extend beyond 10 nm from the sample surface, with zirconium oxides specifically distributing deeper than the oxidized sulfur species. A hard X-ray photoelectron spectroscopy study on the powder and thin film detects signals with minimal contamination contributions and allows for the determination of the valence band maximum position with respect to the Fermi level. Based on these measurements, we establish a correlation between the experimental valence band spectra and the theoretical density of states derived from density functional theory calculations, thereby discerning the orbital constituents involved. Our analysis provides an improved understanding of the electronic structure of BaZrS3 developed through different synthesis protocols by linking it to material geometry, surface chemistry, and the nature of doping. This methodology can thus be adapted for describing electronic structures of chalcogenide perovskite semiconductors in general, a knowledge that is significant for interface engineering and, consequently, for device integration.

3.
Phys Chem Chem Phys ; 26(28): 19460-19468, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38973766

RESUMO

Vibrationally-resolved resonant inelastic X-ray scattering (VR-RIXS) at the O K-edge is emerging as a powerful tool for identifying embedded molecules in lithium-ion battery cathodes. Here, we investigate two known oxygen redox-active cathode materials: the commercial LixNi0.90Co0.05Al0.05O2 (NCA) used in electric vehicles and the high-capacity cathode material Li1.2Ni0.13Co0.13Mn0.54O2 (LRNMC) for next-generation Li-ion batteries. We report the detection of a novel vibrational RIXS signature for Li-ion battery cathodes appearing in the O K pre-peak above 533 eV that we attribute to OH-groups. We discuss likely locations and pathways for OH-group formation and accumulation throughout the active cathode material. Initial-cycle behaviour for LRNMC shows that OH-signal strength correlates with the cathodes state of charge, though reversibility is incomplete. The OH-group RIXS signal strength in long-term cycled NCA is retained. Thus, VR-RIXS offers a path for gaining new insights to oxygen reactions in battery materials.

4.
BMJ Case Rep ; 17(6)2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38901851

RESUMO

This case report describes a man in his 20s presenting with bilateral crypto-orchidism, micropenis and underdeveloped secondary sexual characteristics. The patient also exhibited hyposmia, eunuchoid stature and gynecomastia. Biochemical investigations revealed low levels of testosterone, luteinising hormone and follicle-stimulating hormone. Hence, he was diagnosed with Kallmann syndrome. Imaging studies showed an absent right kidney and cystic dilatation of the distal ureteric bud, seminal vesicle and absent/hypoplastic ejaculatory duct. The association of hypogonadotropic hypogonadism with Zinner syndrome, a rare condition characterised by renal agenesis, seminal vesicle cyst and ejaculatory duct obstruction, was noted.


Assuntos
Hipogonadismo , Síndrome de Kallmann , Humanos , Masculino , Hipogonadismo/complicações , Hipogonadismo/diagnóstico , Síndrome de Kallmann/complicações , Síndrome de Kallmann/diagnóstico , Glândulas Seminais/anormalidades , Glândulas Seminais/diagnóstico por imagem , Rim/anormalidades , Ductos Ejaculatórios/anormalidades , Ductos Ejaculatórios/diagnóstico por imagem , Adulto , Pênis/anormalidades
5.
Diabetes Res Clin Pract ; 210: 111610, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38484983

RESUMO

AIMS: The use of Continuous Glucose Monitoring System (CGMS) improves glycemic parameters in Type 1 Diabetes Mellitus (T1D), but the cost is prohibitive. Here, we investigated the effect of short-term application of real-time and intermittently-scanned CGMS (rt and is-CGMS) in T1D individuals on change in HbA1c at the end of 3 months. METHODS: T1D individuals were randomized into three groups in a ratio of 1:1:2 - Group A (rt-CGMS for 2 weeks initially, followed by is-CGMS for 2 weeks at 3 months), Group B (is-CGMS for 2 weeks initially followed by rt-CGMS for 2 weeks at 3 months) and Group C (only self-monitoring of blood glucose), respectively. HbA1c at baseline, 3, and 6 months were compared. RESULTS: Out of a total 68 T1D patients, HbA1c decreased significantly in groups A and B at 6 months compared to the baseline, but not in group C. HbA1c was significantly lower in Group A compared to Group C at 3 and 6 months. Fructosamine levels significantly decreased in Group B before and after cross-over. Glycemic variability indices improved significantly after cross-over from is-CGMS to rt-CGMS. CONCLUSION: Intermittent application of CGMS for 2 weeks improves short- and long-term blood glucose control in T1D.


Assuntos
Diabetes Mellitus Tipo 1 , Adulto , Humanos , Adolescente , Diabetes Mellitus Tipo 1/tratamento farmacológico , Glicemia , Hemoglobinas Glicadas , Estudos Cross-Over , Automonitorização da Glicemia , Monitoramento Contínuo da Glicose
6.
J Mater Chem A Mater ; 12(4): 2465-2478, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38269086

RESUMO

The rising demand for high-performance lithium-ion batteries, pivotal to electric transportation, hinges on key materials like the Ni-rich layered oxide LiNixCoyAlzO2 (NCA) used in cathodes. The present study investigates the redox mechanisms, with particular focus on the role of oxygen in commercial NCA electrodes, both fresh and aged under various conditions (aged cells have performed >900 cycles until a cathode capacity retention of ∼80%). Our findings reveal that oxygen participates in charge compensation during NCA delithiation, both through changes in transition metal (TM)-O bond hybridization and formation of partially reversible O2, the latter occurs already below 3.8 V vs. Li/Li+. Aged NCA material undergoes more significant changes in TM-O bond hybridization when cycling above 50% SoC, while reversible O2 formation is maintained. Nickel is found to be redox active throughout the entire delithiation and shows a more classical oxidation state change during cycling with smaller changes in the Ni-O hybridization. By contrast, Co redox activity relies on a stronger change in Co-O hybridization, with only smaller Co oxidation state changes. The Ni-O bond displays an almost twice as large change in its bond length on cycling as the Co-O bond. The Ni-O6 octahedra are similar in size to the Co-O6 octahedra in the delithiated state, but are larger in the lithiated state, a size difference that increases with battery ageing. These contrasting redox activities are reflected directly in structural changes. The NCA material exhibits the formation of nanopores upon ageing, and a possible connection to oxygen redox activity is discussed. The difference in interaction of Ni and Co with oxygen provides a key understanding of the mechanism and the electrochemical instability of Ni-rich layered transition metal oxide electrodes. Our research specifically highlights the significance of the role of oxygen in the electrochemical performance of electric-vehicle-grade NCA electrodes, offering important insights for the creation of next-generation long-lived lithium-ion batteries.

7.
Best Pract Res Clin Endocrinol Metab ; 38(2): 101837, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37926613

RESUMO

Primary hyperparathyroidism (PHPT) is a systemic disease that affects all the systems of the body, specifically the bones and the kidneys. Its main action is on calcium homeostasis. It tries to preserve the body's calcium level at the cost of phosphate. The criteria for surgery in asymptomatic PHPT patients revolve around raised serum calcium levels, renal dysfunction or nephrolithiasis, and bone health. It does not take into account the serum phosphate levels. Depending on the serum level, Hypophosphatemia is divided into mild, moderate, and severe categories. In PHPT, several studies have suggested that asymptomatic PHPT patients with moderate hypophosphatemia may warrant surgical intervention. Treatment of hypophosphatemia in PHPT is based upon the degree of hypophosphatemia, and treatment is given according to that oral or intravenous route; after surgical and medical treatment of PHPT, phosphate levels gradually normalized. But even after these considerations, phosphate levels in PHPT are not given much importance.


Assuntos
Hiperparatireoidismo Primário , Hipofosfatemia , Humanos , Cálcio , Hiperparatireoidismo Primário/complicações , Hiperparatireoidismo Primário/cirurgia , Fosfatos , Hormônio Paratireóideo , Hipofosfatemia/etiologia
8.
Opt Express ; 31(21): 35178-35199, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37859255

RESUMO

In hydrological optics, "optical closure" means consistency between the apparent optical properties (AOPs) determined from radiometric measurements and those derived from radiative transfer modelling based on concurrently measured inherent optical properties (IOPs) and boundary conditions (sea and sky states). Good optical closure not only provides confidence in the data quality but also informs on the adequacy of the radiative transfer parameterization. Achieving optical closure in highly absorptive coastal waters is challenging due to the low signal-to-noise ratio of radiometric measurements and uncertainties in the measurements of IOPs, namely the spectral absorption and backscattering coefficients. Here, we present an optical closure assessment using a comprehensive set of in situ IOPs acquired in highly absorptive coastal waters optically dominated by chromophoric dissolved organic matter (CDOM). The spectral remote sensing reflectance, Rrs(λ), was modeled using the software HydroLight (HL) with measured IOPs and observed boundary conditions. Corresponding in-water in situ Rrs(λ) was derived from radiometric measurements made with a Compact Optical Profiling System (C-OPS; Biospherical). The assessment revealed that the inclusion of inelastic scattering processes in the model, specifically sun-induced CDOM fluorescence (fDOM) and sun-induced chlorophyll fluorescence (SICF) from Chlorophyll-a ([chl]), significantly improved the optical closure and led to good agreement between measured and modeled Rrs (i.e., for 440 ≤ λ ≤ 710 nm with no inelastic processes: R2=0.90, slope=0.64; with inelastic processes: R2=0.96, slope=0.90). The analysis also indicated that fDOM and SICF contributed a substantial fraction of the green-red wavelength Rrs in these waters. Specifically, fDOM contributed ∼18% of the modeled Rrs in the green region and SICF accounted for ∼20% of the modeled Rrs in the red region. Overall, this study points out the importance of accounting for fDOM in remote sensing applications in CDOM-dominated waters.

9.
Indian J Pediatr ; 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37713102

RESUMO

Dehydroepiandrosterone sulphate (DHEAS), the biochemical indicator of adrenarche and pubarche, is of paramount importance in the evaluation of puberty-related disorders. The reference range of DHEAS should be ethnicity, age, sex, pubarche and Tanner stage specific. Anthropometry, puberty assessment and hormonal parameters were estimated using electrochemiluminescence assay. Bone age was estimated using the BoneXpert software. Of 2191 healthy Indian children aged 5-18 y screened at Chandigarh, 1919 were included in the final analysis (994 boys). The median DHEAS levels at pubarche stage P2 were 82.10 (55.0-129.0) g/dl in girls and 132.50 (95.12-205.50) g/dl in boys. By ROC analysis, the level of DHEAS at pubarche was 63.7 g/dl (sensitivity 72.6%, specificity 64.4%) in girls and 82.2 g/dl (sensitivity 81.8%, specificity 68.8%) in boys. The median age at adrenarche was 9.5 y in both sexes. On multivariate regression analysis; bone age, body mass index (BMI), gonadal steroids, and insulin-like growth factor-1 (IGF-1) significantly correlated with serum DHEAS levels in either sex.

10.
J Am Chem Soc ; 145(38): 20883-20896, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37705333

RESUMO

Covalent dimers, particularly pentacenes, are the dominant platform for developing a mechanistic understanding of intramolecular singlet fission (iSF). Numerous studies have demonstrated that a photoexcited singlet state in these structures can rapidly and efficiently undergo exciton multiplication to form a correlated pair of triplets within a single molecule, with potential applications from photovoltaics to quantum information science. One of the most significant barriers limiting such dimers is the fast recombination of the triplet pair, which prevents spatial separation and the formation of long-lived triplet states. There is an ever-growing need to develop general synthetic strategies to control the evolution of triplets following iSF and enhance their lifetime. Here, we rationally tune the dihedral angle and interchromophore separation between pairs of pentacenes in a systematic series of bridging units to facilitate triplet separation. Through a combination of transient optical and spin-resonance techniques, we demonstrate that torsion within the linker provides a simple synthetic handle to tune the fine balance between through-bond and through-space interchromophore couplings that steer iSF. We show that the full iSF pathway from femtosecond to microsecond timescales is tuned through the static coupling set by molecular design and structural fluctuations that can be biased through steric control. Our approach highlights a straightforward design principle to generate paramagnetic spin pair states with higher yields.

11.
Diagn Pathol ; 18(1): 93, 2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37563607

RESUMO

BACKGROUND: Cancer progression can be promoted by chronic inflammation. Local immune response may be associated with favourable or unfavourable prognosis of Papillary Thyroid Carcinoma (PTC). Regulatory T (Treg) cells and T helper 17 (Th17) cells exert opposing function and their balance may have a vital role in promotion of tumor growth. Treg cells in tumor microenvironment (TME) may promote tumor progression and reduced survival of patients. Whereas, Th17 cells can promote or inhibit tumor progression depending on phenotypic characteristics of tumor. In this study, we aimed to analyse the kind of immune response developed and its prognostic impact in future therapeutics. METHODS: Cytometric Bead Array (CBA) analysis of pro and anti-inflammatory cytokines (IFN-gamma, IL-2, IL-6, IL-17 A, TNF-alpha and IL-4, IL-10) was done in 15 PTC irrespective of Lymphocytic Thyroiditis (LT) and 16 Hashimoto's Thyroiditis (HT) cases. Immunohistochemical expression of FoxP3 and IL-17 A was studied in 27 cases of PTC with LT. Whereas, quantitative gene expression of both was analysed in 10 cases. RESULTS: All the pro-inflammatory cytokines showed mild elevation in PTC with LT. On IHC, IL-17 A expression was observed in 74% PTC with LT. Whereas, FoxP3 was present in only 40% cases. Also, IL-17 A expression was significantly associated with age group (> 45 years), tumor size ≤ 1 cm and disease progression. CONCLUSIONS: Increased expression of cytokines suggested correlation between inflammatory factors and progression of thyroid tumors. Along with this, the balance between IL-17 A and FoxP3 may play an important role in PTC development, prognosis and future management.


Assuntos
Carcinoma Papilar , Fatores de Transcrição Forkhead , Doença de Hashimoto , Interleucina-17 , Neoplasias da Glândula Tireoide , Humanos , Pessoa de Meia-Idade , Citocinas , Progressão da Doença , Fatores de Transcrição Forkhead/metabolismo , Interleucina-17/metabolismo , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Microambiente Tumoral
12.
BMJ Case Rep ; 16(7)2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37491126

RESUMO

We report a short-statured, young man in his 20s presenting with bilateral cataract, recurrent kidney stones, history of refractory rickets and bone deformity. He had been consuming calcium and vitamin D supplements and had been operated for cataract and renal stone disease, prior to reporting in our clinic without any significant laboratory or clinical improvement. The patient was diagnosed as having Fanconi's syndrome attributable to Wilson's disease. This patient highlights that in case of resistant rickets, a high index of suspicion must be invoked for Wilson's disease. Timely recognition of this entity results in prompt ministrations and prevention of disability.


Assuntos
Doenças Ósseas Metabólicas , Catarata , Degeneração Hepatolenticular , Cálculos Renais , Raquitismo , Masculino , Humanos , Degeneração Hepatolenticular/complicações , Degeneração Hepatolenticular/diagnóstico , Degeneração Hepatolenticular/tratamento farmacológico
13.
Mycoses ; 66(9): 787-794, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37191090

RESUMO

BACKGROUND: Factors associated with pulmonary mucormycosis (PM) among subjects with diabetes mellitus (DM) remain unclear. Following the coronavirus disease (COVID-19)-associated mucormycosis outbreak in India, specific environmental exposures (especially cattle dung exposure) were proposed as possible aetiology. We hypothesized that environmental factors are associated with PM. We compared subjects with DM with (cases) and without PM (controls). METHODS: In this case-control study, for each PM case, we included five unmatched diabetic controls (hospital [n = 2], community [n = 3]) without PM. We collected information on demography, COVID-19 infection, glycated haemoglobin% (HbA1c), the type of house (pucca vs. kutcha) where the participants reside, and other environmental factors. The primary exposure tested was cattle dung exposure (CDE; using cattle dung cakes as fuel or cattle handling). We performed a multivariate logistic regression to explore factors associated with PM and report the association as an adjusted odds ratio (OR) with 95% confidence intervals (CI). RESULTS: We enrolled 39 PM cases and 199 controls (hospital [n = 80], community [n = 119]). CDE (OR 0.68, 95% CI [0.14-3.31]; p = 0.63) was not associated with increased PM in DM. We found male sex (OR 4.07, 95% CI [1.16-14.31]), higher HbA1c (OR 1.51, 95% CI [1.18-16.32]), COVID-19 (OR 28.25, 95% CI [7.02-113.6]) and residence at kutcha house (OR 4.84, 95% CI [1.33-17.52]) associated with PM. CONCLUSION: Cattle dung exposure was not associated with PM in subjects with DM. Instead, male sex, poor glycaemic control, COVID-19 and the type of housing were associated with pulmonary mucormycosis.


Assuntos
COVID-19 , Diabetes Mellitus , Mucormicose , Masculino , Animais , Bovinos , Mucormicose/epidemiologia , Estudos de Casos e Controles , Hemoglobinas Glicadas , COVID-19/complicações , COVID-19/epidemiologia , Diabetes Mellitus/epidemiologia , Fatores de Risco
14.
Hum Pathol ; 135: 45-53, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36921727

RESUMO

Acute myeloid leukemia (AML) is an aggressive hematopoietic malignancy with several patient- and disease-associated variables known to impact prognosis. Tobacco smoking is an environmental factor associated with a greater incidence of AML, but there have been limited studies that evaluated smoking toward overall survival. We retrospectively searched for AML cases and collected clinical and diagnostic data for each case. We also used an independent next-generation sequencing (NGS) data set to assess for a distinct mutational signature associated with smoking. When stratified by smoking status, there was a greater number of males, patients aged ≥60 years, and patients with ≥2 comorbidities within the smoking category (P < .05). Survival analysis demonstrated decreased survival probability in the smokers, male smokers, smokers with 1 other comorbidity, and smokers without a prior history of nonhematopoietic malignancy (P < .05) as compared to nonsmokers. Smoking was associated with a decrease in survival within the World Health Organization categories of AML, not otherwise specified (AML NOS; P = .035) and AML with recurrent genetic abnormalities (AML RGA; P = .002). Multivariate analysis showed that patients who were smokers had a greater hazard ratio than nonsmokers after adjusting for the other covariates. Our findings demonstrated that smoking was independently associated with decreased overall survival after adjusting for other potentially confounding factors. In addition, our results suggest that a mutational signature can be recognized using NGS data in a subset of AML patients who smoke.


Assuntos
Leucemia Mieloide Aguda , Humanos , Masculino , Estudos Retrospectivos , Leucemia Mieloide Aguda/genética , Aberrações Cromossômicas , Prognóstico , Organização Mundial da Saúde , Fumar/efeitos adversos
15.
Clin Endocrinol (Oxf) ; 99(2): 158-164, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36998119

RESUMO

BACKGROUND: It has been a matter of debate for long time about the existence of two distinct phenotypes of primary hyperparathyroidism (PHPT) predisposed to either renal or skeletal manifestation. OBJECTIVE: To differentiate characteristics of symptomatic PHPT patients based on the presence of skeletal or renal involvement. DESIGN: Retrospective analysis of data from the Indian PHPT registry. PATIENTS: PHPT patients were divided into four discrete groups: asymptomatic, presenting with renal manifestations alone, skeletal manifestations alone, and both skeletal and renal manifestations. MEASUREMENTS: Clinical, biochemical, and tumour weight and histopathological characteristics of these groups were compared. RESULTS: Of the 229 eligible patients, 45 were asymptomatic, 62 had renal manifestations, 55 had skeletal manifestations, and 67 had both skeletal and renal manifestations. Patients with both skeletal and renal manifestations had higher serum calcium levels than those with isolated skeletal involvement [12.5 (11.1-13.7) mg/dL, 11.2 (10.6-12.3) mg/dL, respectively; p < .05]. Serum alkaline phosphatase (AP), plasma parathyroid hormone (PTH) levels, and parathyroid tumour weight were significantly higher in patients with isolated skeletal, and both skeletal and renal manifestations, compared to the other two groups. A preoperative PTH and AP level of 300 pg/mL and 152 U/L, predicted the risk of developing skeletal involvement with sensitivity and specificity of 71%, 70%, and 69%, 67%, respectively. CONCLUSIONS: We observed distinct skeletal and renal phenotypic subgroups among PHPT patients with characteristic biochemical and hormonal patterns with higher parathyroid disease burden in patients with skeletal complications compared to those with isolated renal manifestation.


Assuntos
Cálcio , Hiperparatireoidismo Primário , Humanos , Hiperparatireoidismo Primário/cirurgia , Estudos Retrospectivos , Paratireoidectomia , Hormônio Paratireóideo , Sistema de Registros
16.
ACS Omega ; 8(1): 87-97, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36643560

RESUMO

Mechanoenzymes convert chemical energy from the hydrolysis of nucleotide triphosphates to mechanical energy for carrying out cellular functions ranging from DNA unwinding to protein degradation. Protein-processing mechanoenzymes either remodel the protein structures or translocate them across cellular compartments in an energy-dependent manner. Optical-tweezer-based single-molecule force spectroscopy assays have divulged information on details of chemo-mechanical coupling, directed motion, as well as mechanical forces these enzymes are capable of generating. In this review, we introduce the working principles of optical tweezers as a single-molecule force spectroscopy tool and assays developed to decipher the properties such as unfolding kinetics, translocation velocities, and step sizes by protein remodeling mechanoenzymes. We focus on molecular motors involved in protein degradation and disaggregation, i.e., ClpXP, ClpAP, and ClpB, and insights provided by single-molecule assays on kinetics and stepping dynamics during protein unfolding and translocation. Cellular activities such as protein synthesis, folding, and translocation across membranes are also energy dependent, and the recent single-molecule studies decoding the role of mechanical forces on these processes have been discussed.

17.
J Phys Chem B ; 127(1): 104-120, 2023 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-36594702

RESUMO

Elucidation of the photophysical and biochemical properties of small molecules can facilitate their applications as prospective therapeutic imaging (theragnostic) agents. Herein, we demonstrate the luminescence behavior of a strategically designed potential therapeutic thiosemicarbazone derivative, (E)-1-(4-(diethylamino)-2-hydroxybenzylidene)-4,4-dimethylthiosemicarbazide (DAHTS), accompanied by the illustration of its solvation and solvation dynamics using spectroscopic techniques and exploring its promising antitumor activities by adopting the necessary biochemical assays. Solvent-dependent photophysical properties, namely UV-vis absorption, fluorescence emission, and excitation profiles, concentration-dependent studies, and time-resolved fluorescence decays, serve as footprints to explain the existence of DAHTS monomers, its excited-state intramolecular proton transfer (ESIPT) product, and dimeric and aggregated forms. The emission intensity progressively intensifies with increasing polarity and proticity of the solvents up to MeOH, but in water, a sudden dip is seen. Solvent polarity and H-bonding modulate the fluorescence behavior of the primary emission peak and significantly influence the formation of the dimer and DAHTS aggregates. The designed luminophore (DAHTS) exhibits significant antiproliferative activity against the human lung cancer (A549) cell lines with inhibitory concentrations (IC50) of 16.88 and 11.92 µM for 24 and 48 h, respectively. DAHTS effectively reduces the cell viability and induces cytotoxicity with extensive morphological changes in A549 cells in the form of spikes when compared to the normal HEK cell lines. More importantly, it increases the p53 expression at the mRNA level that consolidates its potential therapeutic activity. The effect of DAHTS on apoptotic pathways against the A549 cell line has been investigated to determine its probable mechanism of cell death. Thus, the all-inclusive understanding of the photophysical properties and the necessary biochemical assays put forward important steps toward tailoring the thiosemicarbazone core structure for favorable cancer theragnostic applications in academic and pharmaceutical research.


Assuntos
Neoplasias Pulmonares , Tiossemicarbazonas , Humanos , Tiossemicarbazonas/farmacologia , Solventes/química , Linhagem Celular , Apoptose , Neoplasias Pulmonares/tratamento farmacológico
18.
Small ; 19(1): e2203331, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36403214

RESUMO

Nanocrystalline ZnO sponges doped with 5 mol% EuO1.5 are obtained by heating metal-salt complex based precursor pastes at 200-900 °C for 3 min. X-ray diffraction, transmission electron microscopy, and extended X-ray absorption fine structure (EXAFS) show that phase separation into ZnO:Eu and c-Eu2 O3 takes place upon heating at 700 °C or higher. The unit cell of the clean oxide made at 600 °C shows only ≈0.4% volume increase versus undoped ZnO, and EXAFS shows a ZnO local structure that is little affected by the Eu-doping and an average Eu3+ ion coordination number of ≈5.2. Comparisons of 23 density functional theory-generated structures having differently sized Eu-oxide clusters embedded in ZnO identify three structures with four or eight Eu atoms as the most energetically favorable. These clusters exhibit the smallest volume increase compared to undoped ZnO and Eu coordination numbers of 5.2-5.5, all in excellent agreement with experimental data. ZnO defect states are crucial for efficient Eu3+ excitation, while c-Eu2 O3 phase separation results in loss of the characteristic Eu3+ photoluminescence. The formation of molecule-like Eu-oxide clusters, entrapped in ZnO, proposed here, may help in understanding the nature of the unexpected high doping levels of lanthanide ions in ZnO that occur virtually without significant change in ZnO unit cell dimensions.


Assuntos
Elementos da Série dos Lantanídeos , Óxido de Zinco , Óxido de Zinco/química , Európio/química , Difração de Raios X
19.
NMR Biomed ; 36(3): e4855, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36269130

RESUMO

Changes in glioblastoma (GBM) metabolism was investigated in response to JAS239, a choline kinase inhibitor, using MRS. In addition to the inhibition of phosphocholine synthesis, we investigated changes in other key metabolic pathways associated with GBM progression and treatment response. Three syngeneic rodent models of GBM were used: F98 (N = 12) and 9L (N = 8) models in rats and GL261 (N = 10) in mice. Rodents were intracranially injected with GBM cells in the right cortex and tumor growth was monitored using T2 -weighted images. Animals were treated once daily with intraperitoneal injections of 4 mg/kg JAS239 (F98 rats, n = 6; 9L rats, n = 6; GL261 mice, n = 5) or saline (control group, F98 rats, n = 6; 9L rats, n = 2; GL261 mice, n = 5) for five consecutive days. Single voxel spectra were acquired on Days 0 (T0, baseline) and 6 (T6, end of treatment) from the tumor as well as the contralateral normal brain using a PRESS sequence. Changes in metabolite ratios (tCho/tCr, tCho/NAA, mI/tCr, Glx/tCr and (Lip + Lac)/Cr) were used to assess metabolic pathway alterations in response to JAS239. Tumor growth arrest was noted in all models in response to JAS239 treatment compared with saline-treated animals, with a significant reduction (p < 0.05) in the F98 model. A reduction in tCho/tCr was observed with JAS239 treatment in all GBM models, indicating reduced phospholipid metabolism, with the highest reduction in 9L followed by GL261 and F98 tumors. A significant reduction (p < 0.05) in the tCho/NAA ratio was observed in the 9L model. A significant reduction in mI/tCr (p < 0.05) was found in JAS239-treated F98 tumors compared with the saline-treated animals. A non-significant trend of reduction in Glx/tCr was observed only in F98 and 9L tumors. JAS239-treated F98 tumors also showed a significant increase in Lip + Lac (p < 0.05), indicating increased cell death. This study demonstrated the utility of MRS in assessing metabolic changes in GBM in response to choline kinase inhibition.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Ratos , Camundongos , Animais , Glioblastoma/diagnóstico por imagem , Glioblastoma/tratamento farmacológico , Roedores/metabolismo , Colina Quinase , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Receptores de Antígenos de Linfócitos T , Colina/metabolismo
20.
Arch Pathol Lab Med ; 147(8): 940-948, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-36445717

RESUMO

CONTEXT.­: Evidence of T-cell clonality is often critical in supporting the diagnosis of a T-cell lymphoma. OBJECTIVES.­: To retrospectively explore the significance of copy number losses at the 14q11.2 T-cell receptor α locus in relation to the presence of a T-cell neoplasm and proportion of T cells by targeted next-generation sequencing. DESIGN.­: Targeted next-generation sequencing data from 139 tissue biopsies, including T-cell lymphomas, B-cell lymphomas, classic Hodgkin lymphomas, nonhematopoietic malignancies, and normal samples, were reviewed for copy number losses involving the T-cell receptor α gene segments at chr14q11.2. RESULTS.­: We found that biallelic or homozygous deletion of 14q11.2 was found in most (28 of 33, 84.8%) T-cell lymphomas. The magnitude of 14q11.2 loss showed a statistically significant correlation with the proportion of T cells in lymphoma tissue samples. Copy number losses could also be detected in other lymphomas with high numbers of T cells (8 of 32, 25% of B-cell lymphomas, 4 of 4 classical Hodgkin lymphomas), though biallelic/homozygous deletion of 14q11.2 was not significantly observed outside of T-cell lymphomas. Most nonhematopoietic neoplasms and normal tissues (59 of 64, 92.2%) showed no significant copy number losses involving the T-cell receptor α locus at chr14q11.2. CONCLUSIONS.­: Analysis of copy number losses at the T-cell receptor α locus chr14q11.2 with targeted next-generation sequencing can potentially be used to estimate the proportion of T cells and detect T-cell neoplasms.


Assuntos
Doença de Hodgkin , Linfoma de Células B , Linfoma de Células T Periférico , Linfoma de Células T , Humanos , Variações do Número de Cópias de DNA , Homozigoto , Estudos Retrospectivos , Linfócitos T , Deleção de Sequência , Linfoma de Células B/genética , Doença de Hodgkin/diagnóstico , Doença de Hodgkin/genética , Linfoma de Células T/diagnóstico , Linfoma de Células T/genética , Linfoma de Células T Periférico/genética , Biópsia , Cromossomos , Receptores de Antígenos de Linfócitos T/genética
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