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1.
Nat Chem Biol ; 18(9): 1014-1022, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35836018

RESUMO

Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas12a is widely used for genome editing and diagnostics, so it is important to understand how RNA-guided DNA recognition activates the cleavage of the target strand (TS) following non-target-strand (NTS) cleavage. Here we used single-molecule magnetic tweezers, gel-based assays and nanopore sequencing to explore DNA unwinding and cleavage. In addition to dynamic and heterogenous R-loop formation, we also directly observed transient double-stranded DNA unwinding downstream of the 20-bp heteroduplex and, following NTS cleavage, formation of a hyperstable 'clamped' Cas12a-DNA intermediate necessary for TS cleavage. Annealing of a 4-nucleotide 3' CRISPR RNA overhang to the unwound TS downstream of the heteroduplex inhibited clamping and slowed TS cleavage by ~16-fold. Alanine substitution of a conserved aromatic amino acid in the REC2 subdomain that normally caps the R-loop relieved this inhibition but favoured stabilisation of unwound states, suggesting that the REC2 subdomain regulates access of the 3' CRISPR RNA to downstream DNA.


Assuntos
Sistemas CRISPR-Cas , RNA Guia de Cinetoplastídeos , Sistemas CRISPR-Cas/genética , Constrição , DNA/genética , Clivagem do DNA , Edição de Genes , Conformação de Ácido Nucleico , RNA , RNA Guia de Cinetoplastídeos/genética
2.
Int Wound J ; 20(9): 3639-3647, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37259676

RESUMO

The characteristics of the pilonidal sinus that are associated with recurrence have scarcely been investigated in the literature. This study aims to evaluate the outcomes of patients with sacrococcygeal pilonidal sinus disease who were managed by a non-operative technique using Salih's preparation. This study also tries to classify the patients according to the features that determine the outcome of the intervention. This is a single-group cohort study that enrolled consecutive patients that had pilonidal sinus. All the patients were managed using Salih's preparation. The patients were seen at the clinic 6 weeks after the intervention to record data of recurrence. The Statistical Package for the Social Sciences (SPSS) Version 25 was used for coding and analysing the data. Test of significance and odds ratio were calculated for all of the features. The total number of patients receiving Salih's preparation was 12 123 cases, of which only 3529 patients were included in this study. The mean age of the participants was 26.95 years, ranging from 14 to 55 years. The most significant factor related to the recurrence was the presence of an abscess. After summation of all odd ratios, the percentage of each one from the total was calculated, and accordingly, the patients were divided into three classes. Non-operative methods using a preparation with antimicrobial and sclerosing properties can be an alternative for surgical intervention with a lower risk of recurrence. Classification of patients based on specific criteria can give clinicians and even patients themselves a vision of the chance of recurrence and treatment success.


Assuntos
Seio Pilonidal , Cicatrização , Humanos , Adulto , Seio Pilonidal/cirurgia , Estudos de Coortes , Recidiva Local de Neoplasia , Região Sacrococcígea/cirurgia , Resultado do Tratamento , Recidiva
3.
Catheter Cardiovasc Interv ; 99(2): 254-262, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34767299

RESUMO

BACKGROUND: Women are underrepresented in chronic total occlusion (CTO) trials and little is known about sex differences in the outcomes of CTO percutaneous coronary intervention (PCI). This meta-analysis aims to compare the outcomes of CTO PCI in males and females. METHODS: A comprehensive search of PubMed, EMBASE, Cochrane, Web of Science, and Google Scholar was performed for studies comparing outcomes of CTO PCI in females versus males from inception to January 26, 2021. The current statistical analysis was performed using STATA version 15.1 software (Stata Corporation, TX); P < 0.05 indicated statistical significance. RESULTS: Fourteen observational studies were included in the analysis with 75% males and 25% females. The mean age was 64.47 ± 10.5 years and 68.98 ± 9.5 years for males and females, respectively. The median follow-up duration was 2.4 years. Males had a higher Japanese-CTO (J-CTO) score compared with females (MD = -0.17; 95% CI: -0.25 to -0.10). Females had statistically higher success rates of CTO PCI (RR = 1.03; 95% CI: 1.01 to1.05), required less contrast volume (MD = -18.64: 95% CI: -30.89 to -6.39) and fluoroscopy time (MD = -9.12; 95% CI: -16.90 to -1.34) compared with males. There was no statistical difference in in-hospital (RR = 1.50; 95% CI: 0.73 to 3.09) or longer term (≥6 months) all-cause mortality (RR = 1.10; 95% CI: 0.86 to 1.42) between the two groups. CONCLUSIONS: CTO PCI is feasible and safe in female patients with comparable outcomes in female versus male patients.


Assuntos
Oclusão Coronária , Intervenção Coronária Percutânea , Idoso , Doença Crônica , Angiografia Coronária , Oclusão Coronária/diagnóstico por imagem , Oclusão Coronária/etiologia , Oclusão Coronária/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/efeitos adversos , Fatores de Risco , Resultado do Tratamento
4.
Nucleic Acids Res ; 48(12): 6811-6823, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32496535

RESUMO

A key aim in exploiting CRISPR-Cas is gRNA engineering to introduce additional functionalities, ranging from individual nucleotide changes that increase efficiency of on-target binding to the inclusion of larger functional RNA aptamers or ribonucleoproteins (RNPs). Cas9-gRNA interactions are crucial for complex assembly, but several distinct regions of the gRNA are amenable to modification. We used in vitro ensemble and single-molecule assays to assess the impact of gRNA structural alterations on RNP complex formation, R-loop dynamics, and endonuclease activity. Our results indicate that RNP formation was unaffected by any of our modifications. R-loop formation and DNA cleavage activity were also essentially unaffected by modification of the Upper Stem, first Hairpin and 3' end. In contrast, we found that 5' additions of only two or three nucleotides could reduce R-loop formation and cleavage activity of the RuvC domain relative to a single nucleotide addition. Such modifications are a common by-product of in vitro transcribed gRNA. We also observed that addition of a 20 nt RNA hairpin to the 5' end of a gRNA still supported RNP formation but produced a stable ∼9 bp R-loop that could not activate DNA cleavage. Consideration of these observations will assist in successful gRNA design.


Assuntos
Sistemas CRISPR-Cas/genética , Clivagem do DNA , Estruturas R-Loop/genética , RNA Guia de Cinetoplastídeos/genética , Aptâmeros de Nucleotídeos/genética , Edição de Genes , Conformação de Ácido Nucleico , RNA Guia de Cinetoplastídeos/ultraestrutura , Ribonucleoproteínas/genética , Ribonucleoproteínas/ultraestrutura , Imagem Individual de Molécula , Streptococcus pyogenes/genética
5.
Biophys J ; 118(1): 85-95, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31757359

RESUMO

Holdase chaperones are known to be central to suppressing aggregation, but how they affect substrate conformations remains poorly understood. Here, we use optical tweezers to study how the holdase Hsp33 alters folding transitions within single maltose binding proteins and aggregation transitions between maltose binding protein substrates. Surprisingly, we find that Hsp33 not only suppresses aggregation but also guides the folding process. Two modes of action underlie these effects. First, Hsp33 binds unfolded chains, which suppresses aggregation between substrates and folding transitions within substrates. Second, Hsp33 binding promotes substrate states in which most of the chain is folded and modifies their structure, possibly by intercalating its intrinsically disordered regions. A statistical ensemble model shows how Hsp33 function results from the competition between these two contrasting effects. Our findings reveal an unexpectedly comprehensive functional repertoire for Hsp33 that may be more prevalent among holdases and dispels the notion of a strict chaperone hierarchy.


Assuntos
Proteínas de Choque Térmico/metabolismo , Agregados Proteicos , Dobramento de Proteína , Modelos Moleculares
6.
Br Poult Sci ; 61(5): 518-522, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32347110

RESUMO

1. Immune mapped protein-1 (IMP1) of E. maxima has been identified as a vaccine antigen candidate for E. maxima infection. 2. In the current study, the N- and C-terminal derivative of EmIMP1 were expressed in E. coli and administered to chickens. The antibody response, cell-mediated immune (CMI) response and the protective efficacy of the protein vaccines against E. maxima challenge were evaluated. 3. The results showed that C-terminal derivative of EmIMP1 vaccination could increase weight gain, reduce enteric lesions, and decrease faecal oocysts shedding. Moreover, the C-terminal derivative of EmIMP1 caused reasonable improvement in serum antibodies and the numbers of IFN-γ producing peripheral blood mononuclear cells (PBMC), as compared to the control group. 4. This study demonstrated that the C-terminal derivative of EmIMP1 could be used as a potent immunogenic candidate in the development of subunit vaccines against E. maxima infection.


Assuntos
Coccidiose , Eimeria , Doenças das Aves Domésticas , Vacinas Protozoárias , Animais , Antígenos de Protozoários , Galinhas , Coccidiose/veterinária , Escherichia coli , Leucócitos Mononucleares , Doenças das Aves Domésticas/prevenção & controle
7.
Proc Natl Acad Sci U S A ; 111(36): 13069-74, 2014 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-25157171

RESUMO

Neurodegenerative disorders are strongly linked to protein misfolding, and crucial to their explication is a detailed understanding of the underlying structural rearrangements and pathways that govern the formation of misfolded states. Here we use single-molecule optical tweezers to monitor misfolding reactions of the human neuronal calcium sensor-1, a multispecific EF-hand protein involved in neurotransmitter release and linked to severe neurological diseases. We directly observed two misfolding trajectories leading to distinct kinetically trapped misfolded conformations. Both trajectories originate from an on-pathway intermediate state and compete with native folding in a calcium-dependent manner. The relative probability of the different trajectories could be affected by modulating the relaxation rate of applied force, demonstrating an unprecedented real-time control over the free-energy landscape of a protein. Constant-force experiments in combination with hidden Markov analysis revealed the free-energy landscape of the misfolding transitions under both physiological and pathological calcium concentrations. Remarkably for a calcium sensor, we found that higher calcium concentrations increased the lifetimes of the misfolded conformations, slowing productive folding to the native state. We propose a rugged, multidimensional energy landscape for neuronal calcium sensor-1 and speculate on a direct link between protein misfolding and calcium dysregulation that could play a role in neurodegeneration.


Assuntos
Cálcio/metabolismo , Proteínas Sensoras de Cálcio Neuronal/química , Proteínas Sensoras de Cálcio Neuronal/metabolismo , Neuropeptídeos/química , Neuropeptídeos/metabolismo , Pinças Ópticas , Dobramento de Proteína , Humanos , Cinética , Termodinâmica
8.
Mymensingh Med J ; 26(1): 131-140, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28260767

RESUMO

Increased levels of the inflammatory biomarker high-sensitivity C-reactive protein predict cardiovascular events. Pre-Percutaneoues coronary intervention (PCI) plasma hs-CRP concentration has been reported to influence both short and long term outcome after percutaneoues coronary intervention (PCI). Studies have reported association between pre-PCI CRP and PCI induced cardiac myonecrosis evaluated by sensitive marker of myocardial injury. The present study attempts to evaluate the influence of pre-PCI CRP levels, factors related to the procedure and ongoing medications on the event of post-PCI cardiac myonecrosis. This prospective observational study was done in a Tertiary referral hospital (St. James's Hospital, Dublin, Ireland) involving 38 patients with normal pre-procedural serum troponin T (<0.03µg/litre) undergoing elective PCI. Significantly high basal levels of hs-CRP was detectable in >60% patients undergoing elective PCI. This was further increased to >65% after PCI. Median value of hs-CRP before PCI was 3.61 (range 0.21-47.2mg/L). This value increased to 4.58 (range 0.44-39.2mg/L) after PCI (p<0.05). Though there was significant increase in the post-PCI median value (compared to the pre-PCI value) of TnT (0.015 vs. 0.01µg/L; p<0.001) and CKMBM (4.54 vs. 2.40µg/L; p<0.001), no significant correlation was found between pre-PCI hsCRP and post-PCI TnT (spearman correlation coefficient - 0.074; p=NS) as well as post-PCI CKMBM (spearman correlation coefficient - 0.036; p=NS). The changes in the values of TnT & CKMBM showed moderate positive correlation (spearman correlation coefficient - 0.52; p<0.001). Procedural parameters (of balloon dilatation and stent implantation) did not have significant correlation either. No significant influence of age and ongoing medications was found. Increased hs-CRP levels in serum before PCI was not correlated with significant cardiac myonecrosis detected after PCI.


Assuntos
Cardiomiopatias , Infarto do Miocárdio , Intervenção Coronária Percutânea , Biomarcadores , Proteína C-Reativa , Cardiomiopatias/patologia , Humanos , Infarto do Miocárdio/imunologia , Infarto do Miocárdio/terapia , Necrose , Estudos Prospectivos
9.
Mymensingh Med J ; 25(2): 334-9, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27277368

RESUMO

Despite much research, the pathophysiology of IBS remains poorly understood. So it is very difficult to treat. There is no standard treatment for IBS. Because IBS symptoms can be elicited or exacerbated by diet and stress, this suggests that patient education regarding his or her illness might be beneficial to patients in managing their symptoms. This study was done to see the short term effects of outpatient education in relation to change of symptom score in IBS patients. This is a prospective randomized comparative study. In this study a total of 80 patients were included. Forty patients were given only pharmacological management with Mebevarine hydrochloride 135mg thrice daily half an hour before meal and Amitryptline 10mg at night for six months and another forty were given education in addition to the same pharmacological treatment. In both the study group [medical management only versus medical management with education] changes of symptoms and quality of life of patients of IBS were assessed by using previously used, specially designed symptoms scoring system and a validated IBS-QOL instrument. There was no significant difference in severity of symptoms between only drug treatment group (118.973) and education plus drug treatment group (119.57) before treatment. The difference of improvement between the education group and without education group was not statistically significant (P>0.05), though the subsidence of pain in both the group before and after treatment was statistically significant (P<0.01).


Assuntos
Síndrome do Intestino Irritável/fisiopatologia , Educação de Pacientes como Assunto , Adolescente , Adulto , Bangladesh , Feminino , Humanos , Síndrome do Intestino Irritável/terapia , Masculino , Pessoa de Meia-Idade , Pacientes Ambulatoriais/estatística & dados numéricos , Educação de Pacientes como Assunto/estatística & dados numéricos , Estudos Prospectivos , Qualidade de Vida , Adulto Jovem
10.
Mymensingh Med J ; 25(2): 205-10, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27277348

RESUMO

This descriptive cross sectional study was done for the estimation of thyroid hormone in early pregnancy and it's clinical correlation. It was conducted at the Antenatal Clinic of Mymensingh Medical College Hospital, Mymensingh from December 2010 to November 2011. Total 185 cases in early pregnancy were taken purposively and randomly. Among the pregnant women, age ranged from 18-42 years with the Mean±SD age 25.77±4.96 years, the gestational weeks ranged 6±1 to 13±1weeks having Mean±SD 9.06± 2.49 weeks. The gravida ranged from primi to 8th gravida Mean±SD 1.89±1.10. Haemoglobin level ranged from 9.0 to 13.2gm/dl; Mean±SD 10.90±0.99gm/dl. Mean±SD of serum FT4 was 17.77±7.25 and Mean±SD of TSH was 3.95±2.94mIU/L. In present study, 5.40% (n=10) of the respondents had hypothyroidism and 0.54% (n=1) showed hyperthyroidism. The present study showed that, the incidence of hypothyroidism had relatively increased then the reference ranges but not statistically significant. But hyperthyroidism was within the reference range. This study showed slightly higher percentage of hypothyroidism in both ≤30 (4.52%) and ≥30 (10%) years of age groups especially a bit higher percentage in the elderly group. In present study, hypothyroidism was common among women of lower income group. Present study showed a higher percentage of stillbirth &miscarriage among study population. This study showed a relatively higher prevalence of abnormal thyroid function (especially hypothyroidism) in the study population and suggests the routine screening of thyroid hormone in early pregnancy in addition to routine antenatal care.


Assuntos
Hipertireoidismo/epidemiologia , Hipotireoidismo/epidemiologia , Primeiro Trimestre da Gravidez/sangue , Tireotropina/sangue , Tiroxina/sangue , Adolescente , Adulto , Bangladesh/epidemiologia , Estudos Transversais , Feminino , Humanos , Hipertireoidismo/etiologia , Hipotireoidismo/etiologia , Incidência , Gravidez , Prevalência , Adulto Jovem
11.
Mymensingh Med J ; 25(2): 215-20, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27277350

RESUMO

Stroke is one of the leading causes of death and disability in developed as well as developing countries like Bangladesh. Elevated serum uric acid levels may predict an increased risk for cerebro-vascular (CV) events including stroke. Aim of the study was to measure the serum uric acid level among stroke patients and determine the relationship between serum uric acid level and stroke. This descriptive, cross-sectional study was carried out in Department of Medicine, Mymensingh Medical College Hospital, Mymensingh, Bangladesh to measure serum uric acid level among 102 stroke patients in a period of one year by using non-probability sampling procedure. Finally, collected data were analyzed using SPSS software Version 17.0. It was observed that the mean age of patients was 60.87±8.05 years, of them 80(78.43%) patients were male and the rest 22(21.57%) were female. About 66(64.70%) of respondents were in age group 60 years and above, while 36(35.30%) were in age group 59 years and below. At least 23(22.55%) of stroke patients had elevated serum uric acid with a mean serum uric acid level of 5.18mg/dl and standard deviation 1.26mg/dl. About 23(27.38%) patients in ischemic stroke had elevated serum uric acid whereas 18(100%) patients in hemorrhagic stroke had normal uric acid level. Uric acid level was elevated in ischemic stroke than haemorrhagic stroke patients (p<0.001). High uric acid level may be considered as a risk factor in patients with acute ischemic stroke.


Assuntos
Acidente Vascular Cerebral/sangue , Ácido Úrico/sangue , Adulto , Idoso , Bangladesh , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem
12.
Biophys J ; 109(1): 113-23, 2015 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-26153708

RESUMO

Neuronal calcium sensor-1 (NCS-1) is the primordial member of a family of proteins responsible primarily for sensing changes in neuronal Ca(2+) concentration. NCS-1 is a multispecific protein interacting with a number of binding partners in both calcium-dependent and independent manners, and acting in a variety of cellular processes in which it has been linked to a number of disorders such as schizophrenia and autism. Despite extensive studies on the Ca(2+)-activated state of NCS proteins, little is known about the conformational dynamics of the Mg(2+)-bound and apo states, both of which are populated, at least transiently, at resting Ca(2+) conditions. Here, we used optical tweezers to study the folding behavior of individual NCS-1 molecules in the presence of Mg(2+) and in the absence of divalent ions. Under tension, the Mg(2+)-bound state of NCS-1 unfolds and refolds in a three-state process by populating one intermediate state consisting of a folded C-domain and an unfolded N-domain. The interconversion at equilibrium between the different molecular states populated by NCS-1 was monitored in real time through constant-force measurements and the energy landscapes underlying the observed transitions were reconstructed through hidden Markov model analysis. Unlike what has been observed with the Ca(2+)-bound state, the presence of Mg(2+) allows both the N- and C-domain to fold through all-or-none transitions with similar refolding rates. In the absence of divalent ions, NCS-1 unfolds and refolds reversibly in a two-state reaction involving only the C-domain, whereas the N-domain has no detectable transitions. Overall, the results allowed us to trace the progression of NCS-1 folding along its energy landscapes and provided a solid platform for understanding the conformational dynamics of similar EF-hand proteins.


Assuntos
Magnésio/química , Proteínas Sensoras de Cálcio Neuronal/química , Neuropeptídeos/química , Dobramento de Proteína , Cátions Bivalentes/química , Simulação por Computador , Escherichia coli , Humanos , Cinética , Cadeias de Markov , Pinças Ópticas , Análise Espectral , Termodinâmica
13.
J Neurosci ; 33(27): 11262-75, 2013 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-23825429

RESUMO

Transcranial direct current stimulation (tDCS) has emerged as a potentially safe and effective brain stimulation modality that alters cortical excitability by passing a small, constant electric current through the scalp. tDCS creates an electric field that weakly modulates the membrane voltage of a large number of cortical neurons. Recent human studies have suggested that sine-wave stimulation waveforms [transcranial alternating current stimulation (tACS)] represent a more targeted stimulation paradigm for the enhancement of cortical oscillations. Yet, the underlying mechanisms of how periodic, weak global perturbations alter the spatiotemporal dynamics of large-scale cortical network dynamics remain a matter of debate. Here, we simulated large-scale networks of spiking neuron models to address this question in endogenously rhythmic networks. We identified distinct roles of the depolarizing and hyperpolarizing phases of tACS in entrainment, which entailed moving network activity toward and away from a strong nonlinearity provided by the local excitatory coupling of pyramidal cells. Together, these mechanisms gave rise to resonance dynamics characterized by an Arnold tongue centered on the resonance frequency of the network. We then performed multichannel extracellular recordings of multiunit firing activity during tACS in anesthetized ferrets (Mustela putoris furo), a model species with a gyrencephalic brain, to verify that weak global perturbations can selectively enhance oscillations at the applied stimulation frequency. Together, these results provide a detailed mechanistic understanding of tACS at the level of large-scale network dynamics and support the future design of activity-dependent feedback tACS paradigms that dynamically tailor stimulation frequency to the spectral peak of ongoing brain activity.


Assuntos
Córtex Cerebral/fisiologia , Redes Neurais de Computação , Estimulação Magnética Transcraniana/métodos , Animais , Furões , Humanos
14.
J Biol Chem ; 288(43): 30917-30, 2013 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-24014031

RESUMO

Systemic amyloidosis is a fatal disease caused by misfolding of native globular proteins, which then aggregate extracellularly as insoluble fibrils, damaging the structure and function of affected organs. The formation of amyloid fibrils in vivo is poorly understood. We recently identified the first naturally occurring structural variant, D76N, of human ß2-microglobulin (ß2m), the ubiquitous light chain of class I major histocompatibility antigens, as the amyloid fibril protein in a family with a new phenotype of late onset fatal hereditary systemic amyloidosis. Here we show that, uniquely, D76N ß2m readily forms amyloid fibrils in vitro under physiological extracellular conditions. The globular native fold transition to the fibrillar state is primed by exposure to a hydrophobic-hydrophilic interface under physiological intensity shear flow. Wild type ß2m is recruited by the variant into amyloid fibrils in vitro but is absent from amyloid deposited in vivo. This may be because, as we show here, such recruitment is inhibited by chaperone activity. Our results suggest general mechanistic principles of in vivo amyloid fibrillogenesis by globular proteins, a previously obscure process. Elucidation of this crucial causative event in clinical amyloidosis should also help to explain the hitherto mysterious timing and location of amyloid deposition.


Assuntos
Amiloide/química , Mutação de Sentido Incorreto , Dobramento de Proteína , alfa-Cristalinas/química , Microglobulina beta-2/química , Substituição de Aminoácidos , Amiloide/genética , Amiloide/metabolismo , Amiloidose Familiar/genética , Amiloidose Familiar/metabolismo , Humanos , Estrutura Quaternária de Proteína , alfa-Cristalinas/genética , alfa-Cristalinas/metabolismo , Microglobulina beta-2/genética , Microglobulina beta-2/metabolismo
15.
Sci Adv ; 10(22): eadn2208, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38820156

RESUMO

PR65 is the HEAT repeat scaffold subunit of the heterotrimeric protein phosphatase 2A (PP2A) and an archetypal tandem repeat protein. Its conformational mechanics plays a crucial role in PP2A function by opening/closing substrate binding/catalysis interface. Using in silico saturation mutagenesis, we identified PR65 "hinge" residues whose substitutions could alter its conformational adaptability and thereby PP2A function, and selected six mutations that were verified to be expressed and soluble. Molecular simulations and nanoaperture optical tweezers revealed consistent results on the specific effects of the mutations on the structure and dynamics of PR65. Two mutants observed in simulations to stabilize extended/open conformations exhibited higher corner frequencies and lower translational scattering in experiments, indicating a shift toward extended conformations, whereas another displayed the opposite features, confirmed by both simulations and experiments. The study highlights the power of single-molecule nanoaperture-based tweezers integrated with in silico approaches for exploring the effect of mutations on protein structure and dynamics.


Assuntos
Simulação de Dinâmica Molecular , Pinças Ópticas , Mutação Puntual , Conformação Proteica , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/química , Proteína Fosfatase 2/metabolismo , Humanos
16.
Trop Anim Health Prod ; 45(4): 1047-50, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23117622

RESUMO

Micronutrients when fed around peripartum may reduce the stress induced by cortisol. With this objective, 24 Sahiwal (SW) and 24 Karan Fries (KF) cows and 24 Murrah (Mu) buffaloes were taken and divided into four groups of six each. Vitamin E (VE), zinc (Zn) and copper were supplemented from 30 days pre- to 30 days postcalving in groups 1, 2 and 3. Animals without supplementation served as control. Blood sampling was done on days 30, 15, 7 and 3 precalving; at calving; and on days 3, 7, 15 and 30 postcalving. Plasma cortisol levels were measured by ELISA. Supplementation of VE and Zn significantly (P<0.05) reduced plasma cortisol levels at calving and at 30 days postcalving. KF cows exhibited best results with VE, whereas SW cows and Mu buffaloes responded best to Zn. Copper increased the peripartum cortisol levels. Reduction in cortisol levels may help in keeping the animal healthy and stronger to fight immuno-suppression generally observed around the period of peripartum.


Assuntos
Búfalos/sangue , Bovinos/sangue , Cobre/administração & dosagem , Suplementos Nutricionais , Hidrocortisona/sangue , Vitamina E/administração & dosagem , Zinco/administração & dosagem , Animais , Feminino , Período Periparto , Gravidez
17.
Braz J Biol ; 84: e267494, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36722678

RESUMO

Emergence of plasmid mediated colistin and extended spectrum ß-lactamases (ESBL) resistant genes has been impacted the efficacy of colistin and ß-lactams drugs like 3rd, 4th generation cephalosporin. Current study was aimed to investigate antimicrobial resistance genes (ARGs) among Escherichia coli isolates from meat producing commercial broilers in Pakistan. Two hundred (n=200) fecal samples were collected during January-2018 to August-2019. For isolation of E. coli, pink colonies on MacConkey agar were transferred to EMB agar. Metallic sheen color colonies were tested biochemically using API-20E kit. The molecular identification of E. coli (n=153) was targeted by amplification of uid gene through polymerase chain reaction (PCR) and different ARGs i.e. gentamicin, streptomycin, tetracycline, colistin, ß-lactams drugs, quinolone and ampicillin followed by sequence analysis. Genotypically, followed by phenotypically of resistant ARGs of isolated PCR-confirmed E. coli (153) shoed resistant against gentamicin (aac(3)-IV), streptomycin (aadA1), tetracycline (tetA), colistine (mcr-1), ampicillin (bla-TEM) and bla-CTX-M were 86%, 88%, 86%, 88%, 83% & 77% respectively. 33/38 (86%) of the isolate was positive for quinolone resistance. Colistine (mcr-1), ESBLs (bla-TEM) and (bla-CTX-M) resistance genes were 88%, 83% and 77% respectively. About 33 isolated E. coli harbored the both mcr-1 and ESBLs genes. All of E. coli isolates were found sensitive to ceftriaxone (CTX-30) and imipenem (IMP-10). The Isolated E. coli showed single or multi clade decadency. The E. coli and ARGs sequences showed single or multi clade decadency. This is first comprehensive study from Pakistan that described the molecular evidences of ARGs and their co-existence in single isolates originated from commercial poultry. Commercial chicken (Broilers) can act as melting pot of antibiotic resistance genes for human being. It is alarming situation for surveillance of antibiotic resistance program because of more regulated prescription of antimicrobial agents in Pakistan.


Assuntos
Colistina , Proteínas de Escherichia coli , Animais , Humanos , Colistina/farmacologia , Galinhas , Escherichia coli/genética , Paquistão , Ágar , Antibacterianos/farmacologia , Ampicilina , Tetraciclina , Estreptomicina , Proteínas de Escherichia coli/genética
18.
J Int Med Res ; 51(2): 3000605231154392, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36799092

RESUMO

OBJECTIVE: The incidence of thyroglossal duct diseases in the general population is about 7%. We aimed to demonstrate the clinical presentations and management of thyroglossal duct diseases. METHODS: We conducted a retrospective review of all patients who underwent surgery for histopathologically confirmed thyroglossal duct cyst, sinus, or fistula at a single center. RESULTS: A total of 151 cases were included in this study. There were more female patients (87, 58%) than male patients (64, 42%). The patients' ages ranged from 1 to 63 years old. The most prevalent complaint was painless upper midline neck swelling (93.3%). Most cases were diagnosed as thyroglossal duct cysts (137, 90.7%). Six cases (4%) were associated with carcinoma. All the cases were managed using the modified Sistrunk procedure. There were no procedure-related complications, and five cases of recurrence. CONCLUSIONS: Although thyroglossal duct cyst is the most common neck anomaly in children, it may also present with various characteristics later in life. This condition can be managed successfully without complications and with a low recurrence rate.


Assuntos
Carcinoma , Cisto Tireoglosso , Criança , Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Cisto Tireoglosso/diagnóstico , Cisto Tireoglosso/cirurgia , Cisto Tireoglosso/patologia , Glândula Tireoide/patologia , Estudos Retrospectivos
19.
Sci Adv ; 8(9): eabl6293, 2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35245117

RESUMO

The collapse of polypeptides is thought important to protein folding, aggregation, intrinsic disorder, and phase separation. However, whether polypeptide collapse is modulated in cells to control protein states is unclear. Here, using integrated protein manipulation and imaging, we show that the chaperonin GroEL-ES can accelerate the folding of proteins by strengthening their collapse. GroEL induces contractile forces in substrate chains, which draws them into the cavity and triggers a general compaction and discrete folding transitions, even for slow-folding proteins. This collapse enhancement is strongest in the nucleotide-bound states of GroEL and is aided by GroES binding to the cavity rim and by the amphiphilic C-terminal tails at the cavity bottom. Collapse modulation is distinct from other proposed GroEL-ES folding acceleration mechanisms, including steric confinement and misfold unfolding. Given the prevalence of collapse throughout the proteome, we conjecture that collapse modulation is more generally relevant within the protein quality control machinery.

20.
Am J Cardiol ; 175: 65-71, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35595555

RESUMO

Heart transplant (HT) recipients represent a unique and vulnerable population in whom medium and long-term outcomes are significantly affected by the risk of arrhythmias and sudden cardiac death. The use of implantable cardioverter-defibrillators (ICDs) in this population remains debated. A retrospective analysis of the National Inpatient Sample data between 2009 and 2018 was conducted. Hospitalization data on patients who underwent HT, or who had a preexisting HT, and who received a new ICD were included (excluding the preexisting ICD). Outcomes assessed included inpatient mortality, length of stay, and inflation-adjusted costs. We explored temporal trends in ICD placement and mean length of stay, and predictors of ICD placement. Between 2009 and 2018, 22,673 hospitalizations were recorded for HT, during which patients either received a concurrent new ICD placement (n = 70 [0.31%]) or no new ICD placement (n = 22,603 [99.7%]). During the same period, 146,555 admissions were recorded in patients with a history of HT. ICD placement in patients with a preexisting HT was associated with significantly higher inflation-adjusted costs ($55,680.7 vs $17,219.2; p <0.001). Predictors of ICD placement in preexisting patients with HT included cardiac arrest during hospitalization (odds ratio [OR]:14.3 [3.5 to 58.6]), drug abuse (OR:6.0 [1.3 to 27.1]), and previous PCI (OR:6.0 [2.1 to 17.3]). In conclusion, ICD placement in patients with HT history was associated with significantly higher inflation-adjusted costs. In patients with HT history, factors predicting ICD placement included cardiac arrest at hospitalization, previous PCI, and drug abuse.


Assuntos
Desfibriladores Implantáveis , Parada Cardíaca , Transplante de Coração , Intervenção Coronária Percutânea , Morte Súbita Cardíaca/epidemiologia , Humanos , Pacientes Internados , Estudos Retrospectivos
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