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1.
Indian Dermatol Online J ; 15(3): 492-495, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38845649

RESUMO

Imatinib and nilotinib are inhibitors of tyrosine kinases (TKIs) generated from the bcr-abl fusion protein, c-Kit, and platelet-derived growth factor receptors. Cutaneous adverse effects (AEs) of TKI are the most frequent non-hematological sequelae. In our case, the common molecular target raises the possibility that cross-intolerance, in which similar AEs occur with both agents, can arise. We hereby report a rare case report on cross-intolerance of cutaneous AEs of imatinib and nilotinib in chronic myeloid leukemia.

3.
Retina ; 43(6): 940-946, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36791396

RESUMO

PURPOSE: To compare the outcomes of immediate pars plana vitrectomy (PPV) and tap and inject in eyes with postcataract surgery endophthalmitis. METHODS: Patients presenting with acute postcataract surgery endophthalmitis and visual acuity between ≥ hand movement and <6/18 were randomized to receive either PPV (Group A) or tap and inject (Group B). RESULTS: There were 26 and 31 eyes in Group A and Group B, respectively. The final mean visual acuity at 6 weeks [0.14 (Snellen equivalent 6/7.5) versus 0.22 (Snellen equivalent 6/9.5) LogMAR in Groups A and B, respectively; P = 0.2] was similar. However, eyes in Group A had significantly greater mean letter gain in vision compared with Group B (66.36 vs. 43.36, P = 0.02), and more eyes in Group A (88%) than in Group B (65%) attained a visual acuity of ≥ 6/18 ( P = 0.06). Eyes in Group B needed more reinterventions including delayed vitrectomy after tap and inject than those in Group A (39% vs. 8%; P = 0.09). On subgroup analysis, the mean visual acuity at the final follow-up was significantly better in the immediate PPV group compared with the delayed PPV group ( P = 0.04). CONCLUSION: PPV resulted in earlier recovery, lesser interventions, and greater change in visual acuity than tap and inject in eyes with postcataract surgery endophthalmitis presenting with visual acuity of ≥HM.


Assuntos
Endoftalmite , Infecções Oculares Bacterianas , Humanos , Vitrectomia/métodos , Antibacterianos/uso terapêutico , Infecções Oculares Bacterianas/tratamento farmacológico , Endoftalmite/etiologia , Endoftalmite/cirurgia , Endoftalmite/tratamento farmacológico , Corpo Vítreo , Acuidade Visual , Doença Aguda , Estudos Retrospectivos
4.
Ocul Immunol Inflamm ; : 1-4, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36701770

RESUMO

PURPOSE: To report a case of disseminated TB presenting as ciliary body and thyroid mass lesions. CASE REPORT: A 17-year-old male patient presented with a thyroid mass and blurring of vision in the left eye. A diagnosis of ciliary body granuloma was made. Although the Mantoux was negative, the HRCT chest showed evidence of miliary TB, and the fine needle aspiration cytology from the thyroid mass revealed AFB. On initiation of Antitubercular therapy(ATT), a paradoxical worsening of ciliary body granuloma was noted which resolved on starting steroids. CONCLUSION: Involvement of thyroid gland and ciliary body although rare in tuberculosis, may be the presenting feature of disseminated TB. Paradoxical reactions seen after initiation of ATT in these cases may respond well to oral steroids.

5.
J Biol Chem ; 298(10): 102399, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35988639

RESUMO

The NtrC family of proteins senses external stimuli and accordingly stimulates stress and virulence pathways via activation of associated σ54-dependent RNA polymerases. However, the structural determinants that mediate this activation are not well understood. Here, we establish using computational, structural, biochemical, and biophysical studies that MopR, an NtrC protein, harbors a dynamic bidirectional electrostatic network that connects the phenol pocket to two distal regions, namely the "G-hinge" and the "allosteric linker." While the G-hinge influences the entry of phenol into the pocket, the allosteric linker passes the signal to the downstream ATPase domain. We show that phenol binding induces a rewiring of the electrostatic connections by eliciting dynamic allostery and demonstrates that perturbation of the core relay residues results in a complete loss of ATPase stimulation. Furthermore, we found a mutation of the G-hinge, ∼20 Å from the phenol pocket, promotes altered flexibility by shifting the pattern of conformational states accessed, leading to a protein with 7-fold enhanced phenol binding ability and enhanced transcriptional activation. Finally, we conducted a global analysis that illustrates that dynamic allostery-driven conserved community networks are universal and evolutionarily conserved across species. Taken together, these results provide insights into the mechanisms of dynamic allostery-mediated conformational changes in NtrC sensor proteins.


Assuntos
Regulação Alostérica , Proteínas de Bactérias , Técnicas Biossensoriais , Fenol , Transativadores , Adenosina Trifosfatases , Fenol/química , Ligação Proteica , Domínios Proteicos , Proteínas de Bactérias/química , Transativadores/química
6.
J Bacteriol ; 204(8): e0017922, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35862728

RESUMO

The NtrC family of AAA+ proteins are bacterial transcriptional regulators that control σ54-dependent RNA polymerase transcription under certain stressful conditions. MopR, which is a member of this family, is responsive to phenol and stimulates its degradation. Biochemical studies to understand the role of ATP and phenol in oligomerization and allosteric regulation, which are described here, show that MopR undergoes concentration-dependent oligomerization in which dimers assemble into functional hexamers. The oligomerization occurs in a nucleation-dependent manner with a tetrameric intermediate. Additionally, phenol binding is shown to be responsible for shifting MopR's equilibrium from a repressed state (high affinity toward ATP) to a functionally active, derepressed state with low-affinity for ATP. Based on these findings, we propose a model for allosteric regulation of MopR. IMPORTANCE The NtrC family of bacterial transcriptional regulators are enzymes with a modular architecture that harbor a signal sensing domain followed by a AAA+ domain. MopR, a NtrC family member, responds to phenol and activates phenol adaptation pathways that are transcribed by σ54-dependent RNA polymerases. Our results show that for efficient ATP hydrolysis, MopR assembles as functional hexamers and that this activity of MopR is regulated by its effector (phenol), ATP, and protein concentration. Our findings, and the kinetic methods we employ, should be useful in dissecting the allosteric mechanisms of other AAA+ proteins, in general, and NtrC family members in particular.


Assuntos
Proteínas de Ligação a DNA , Transativadores , Trifosfato de Adenosina/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Hidrólise , Fenol , Fenóis , Transativadores/genética , Fatores de Transcrição/metabolismo
8.
Indian J Anaesth ; 65(2): 128-132, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33776087

RESUMO

BACKGROUND AND AIMS: Anxiety causing stress is most profound before surgery. Anxiolytics are used routinely to combat perioperative anxiety. Studies have shown that hand-holding and communication are useful in reducing anxiety levels intraoperatively. This study compares the effectiveness of the same with pharmacological interventions in allaying preoperative anxiety. MATERIAL AND METHODS: This is a three-arm parallel-group randomised controlled trial. A total of 90 adult patients aged <45 years and of American Society of Anesthesiologists (ASA) grade 1-2, undergoing laparoscopic surgery were enroled in this study. Patients received either intravenous (IV) midazolam (group M) or hand-holding and conversation (group HC), or a combination of IV midazolam and holding and conversation (group HCM) in the preoperative room. Anxiety, heart rate (HR) and mean blood pressure (MBP) were recorded before and 20 minutes after the intervention. Anxiety was measured using the Amsterdam preoperative anxiety and information scale. The analysis of covariance (ANCOVA) test was done to analyse the difference between the groups. RESULTS: The mean anxiety scores were significantly different in the three groups (p = 0.04) after intervention, with the lowest score in group HCM, followed by group HC and the highest score in group M. The mean heart rates were also significantly different in the three groups after intervention but MBP was not significantly different in the three groups. CONCLUSION: A combination of hand-holding and conversation and midazolam is best for allaying preoperative anxiety in patients undergoing laparoscopic surgeries than either method alone.

9.
Ther Hypothermia Temp Manag ; 11(2): 77-87, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32302519

RESUMO

Mild therapeutic hypothermia is protective against several cellular stresses, but the mechanisms underlying this protection are not completely resolved. In the present study, we used an in vitro model to investigate whether therapeutic hypothermia at 33°C applied following a peroxide-induced oxidative stress would protect PC12 cells. A 1-hour exposure to tert-butyl peroxide increased cell death measured 24 hours later. This cell death was dose-dependent in the range of 100-1000 µM tert-butyl peroxide with ∼50% cell death observed at 24 hours from 500 µM peroxide exposure. Cell survival/death was measured with an alamarBlue viability assay, and propidium iodide/Hoechst imaging for counts of living and dead cells. Therapeutic hypothermia at 33°C applied for 2 hours postperoxide exposure significantly increased cell survival measured 24 hours postperoxide-induced stress. This protection was present even when delayed hypothermia, 15 minutes after the peroxide washout, was applied. Addition of any of the three FDA-approved antioxidants (Tempol, EUK134, Edaravone at 100 µM) in combination with hypothermia improved cell survival. With the therapeutic hypothermia treatment, a significant downregulation of caspases-3 and -8 and tumor necrosis factor-α was observed at 3 and 24 hours poststress. Consistent with this, a cell-permeable pan-caspase inhibitor Z-VAD-FMK applied in combination with hypothermia significantly increased cell survival. Overall, these results suggest that the antioxidants quenching of reactive oxygen species likely works with hypothermia to reduce mitochondrial damage and/or apoptotic mechanisms. Further studies are required to confirm and extend these results to other cell types, including neuronal cells, and other forms of oxidative stress as well as to optimize the critical parameters of hypothermia treatment such as target temperature and duration.


Assuntos
Antioxidantes , Hipotermia Induzida , Animais , Antioxidantes/farmacologia , Apoptose , Peróxido de Hidrogênio , Estresse Oxidativo , Células PC12 , Ratos
11.
Pediatr Dermatol ; 34(5): e241-e244, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28771811

RESUMO

Idiopathic calcinosis cutis is very rare and difficult to treat. Various medical modalities of treatment described with inconsistent results include chelating agents, colchicine, and probenecid. Calcium channel blockers are known to work by inhibiting intracellular entry of calcium. We successfully treated a case of idiopathic calcinosis cutis using oral diltiazem.


Assuntos
Calcinose/tratamento farmacológico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Diltiazem/uso terapêutico , Dermatopatias/tratamento farmacológico , Administração Oral , Adolescente , Cálcio/metabolismo , Humanos , Masculino , Pele/patologia
12.
Cardiovasc Res ; 113(6): 633-643, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28453726

RESUMO

AIMS: Cardiac myocyte hypertrophy, the main compensatory response to chronic stress in the heart often progresses to a state of decompensation that can lead to heart failure. Osteopontin (OPN) is an effector for extracellular signalling that induces myocyte growth and fibrosis. Although increased OPN activity has been observed in stressed myocytes and fibroblasts, the detailed and long term effects of blocking OPN signalling on the heart remain poorly defined. Targeting cardiac OPN protein by an RNA aptamer may be beneficial for tuning down OPN pathologic signalling. We aimed to demonstrate the therapeutic effects of an OPN RNA aptamer on cardiac dysfunction. METHODS AND RESULTS: In vivo, we show that in a mouse model of pressure overload, treating at the time of surgeries with an OPN aptamer prevented cardiomyocyte hypertrophy and cardiac fibrosis, blocked OPN downstream signalling (PI3K and Akt phosphorylation), reduced expression of extracellular matrix (Lum, Col3a1, Fn1) and hypertrophy (Nppa, Nppb) genes, and prevented cardiac dysfunction. Treating at two months post-surgeries with the OPN aptamer reversed cardiac dysfunction and fibrosis and myocyte hypertrophy. While genetic homozygous deletion of OPN reduced myocardial wall thickness, surprisingly cardiac function and myocardial fibrosis, specifically collagen deposition and myofibroblast infiltration, were worse compared with wild type mice at three months of pressure overload. CONCLUSION: Taken together, these data demonstrate that tuning down cardiac OPN signalling by an OPN RNA aptamer is a novel and effective approach for preventing cardiac hypertrophy and fibrosis, improving cardiac function, and reversing pressure overload-induced heart failure.


Assuntos
Aorta/fisiopatologia , Aptâmeros de Nucleotídeos/metabolismo , Pressão Arterial , Insuficiência Cardíaca/prevenção & controle , Hipertrofia Ventricular Esquerda/prevenção & controle , Miocárdio/metabolismo , Osteopontina/metabolismo , Disfunção Ventricular Esquerda/prevenção & controle , Função Ventricular Esquerda , Remodelação Ventricular , Animais , Aorta/cirurgia , Aptâmeros de Nucleotídeos/genética , Colágeno Tipo III/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Fibrose , Regulação da Expressão Gênica , Predisposição Genética para Doença , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/fisiopatologia , Hipertrofia Ventricular Esquerda/genética , Hipertrofia Ventricular Esquerda/metabolismo , Hipertrofia Ventricular Esquerda/fisiopatologia , Ligadura , Lumicana/metabolismo , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miocárdio/patologia , Osteopontina/deficiência , Osteopontina/genética , Fenótipo , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Fatores de Tempo , Disfunção Ventricular Esquerda/genética , Disfunção Ventricular Esquerda/metabolismo , Disfunção Ventricular Esquerda/fisiopatologia
13.
Cell Death Dis ; 7(9): e2378, 2016 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-27685622

RESUMO

Arginyltransferase 1 (Ate1) mediates protein arginylation, a poorly understood protein posttranslational modification (PTM) in eukaryotic cells. Previous evidence suggest a potential involvement of arginylation in stress response and this PTM was traditionally considered anti-apoptotic based on the studies of individual substrates. However, here we found that arginylation promotes cell death and/or growth arrest, depending on the nature and intensity of the stressing factor. Specifically, in yeast, mouse and human cells, deletion or downregulation of the ATE1 gene disrupts typical stress responses by bypassing growth arrest and suppressing cell death events in the presence of disease-related stressing factors, including oxidative, heat, and osmotic stresses, as well as the exposure to heavy metals or radiation. Conversely, in wild-type cells responding to stress, there is an increase of cellular Ate1 protein level and arginylation activity. Furthermore, the increase of Ate1 protein directly promotes cell death in a manner dependent on its arginylation activity. Finally, we found Ate1 to be required to suppress mutation frequency in yeast and mammalian cells during DNA-damaging conditions such as ultraviolet irradiation. Our study clarifies the role of Ate1/arginylation in stress response and provides a new mechanism to explain the link between Ate1 and a variety of diseases including cancer. This is also the first example that the modulation of the global level of a PTM is capable of affecting DNA mutagenesis.


Assuntos
Aminoaciltransferases/metabolismo , Arginina/metabolismo , DNA/metabolismo , Mutagênese/genética , Processamento de Proteína Pós-Traducional , Proteínas de Saccharomyces cerevisiae/metabolismo , Estresse Fisiológico , Animais , Sequência de Bases , Morte Celular , Sobrevivência Celular/efeitos da radiação , Dano ao DNA , Regulação para Baixo , Embrião de Mamíferos/citologia , Fibroblastos/metabolismo , Técnicas de Silenciamento de Genes , Camundongos , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Raios Ultravioleta , Regulação para Cima
14.
Cardiovasc Res ; 106(1): 131-42, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25678587

RESUMO

AIMS: Activation of an osteogenic transcriptional program contributes to the initiation of aortic calcification in atherosclerosis. The role of microRNAs in regulating aortic calcification is understudied. We tested the hypothesis that miR-30e regulates an osteogenic program in bone marrow-derived mesenchymal stem cells (MSCs), aortic smooth muscle cells (SMCs), and ApoE(-/-) mice. METHODS AND RESULTS: In aortas of wild-type mice, we found that miR-30e is highly expressed in medial SMCs. In aortas of old ApoE(-/-) mice, we found that miR-30e transcripts are down-regulated in an inverse relation to the osteogenic markers Runx2, Opn, and Igf2. In vitro, miR-30e over-expression reduced the proliferation of MSCs and SMCs while increasing adipogenic differentiation of MSCs and smooth muscle differentiation of SMCs. In MSCs and SMCs over-expressing miR-30e, microarrays and qPCR showed repression of an osteogenic gene panel including Igf2. Inhibiting miR-30e in MSCs increased Igf2 transcripts. In SMCs, IGF2 recombinant protein rescued miR-30e-repressed osteogenic differentiation. Luciferase and mutagenesis assays showed binding of miR-30e to a novel and essential site at the 3'UTR of Igf2. In ApoE(-/-) mice, injections of antimiR-30e oligos increased Igf2 expression in the aortas and livers and significantly enhanced OPN protein expression and calcium deposition in aortic valves. CONCLUSION: miR-30e represses the osteogenic program in MSCs and SMCs by targeting IGF2 and drives their differentiation into adipogenic or smooth muscle lineage, respectively. Our data suggest that down-regulation of miR-30e in aortas with age and atherosclerosis triggers vascular calcification. The miR-30e pathway plays an important regulatory role in vascular diseases.


Assuntos
Apolipoproteínas E/deficiência , Fator de Crescimento Insulin-Like II/fisiologia , Células-Tronco Mesenquimais/fisiologia , MicroRNAs/fisiologia , Músculo Liso Vascular/fisiologia , Osteogênese/fisiologia , Envelhecimento/fisiologia , Animais , Aorta/citologia , Apolipoproteínas E/genética , Apolipoproteínas E/fisiologia , Células da Medula Óssea/citologia , Calcinose/fisiopatologia , Diferenciação Celular/fisiologia , Células Cultivadas , Modelos Animais de Doenças , Regulação para Baixo/fisiologia , Masculino , Células-Tronco Mesenquimais/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Liso Vascular/citologia
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