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1.
Cell ; 185(19): 3520-3532.e26, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-36041435

RESUMO

We use computational design coupled with experimental characterization to systematically investigate the design principles for macrocycle membrane permeability and oral bioavailability. We designed 184 6-12 residue macrocycles with a wide range of predicted structures containing noncanonical backbone modifications and experimentally determined structures of 35; 29 are very close to the computational models. With such control, we show that membrane permeability can be systematically achieved by ensuring all amide (NH) groups are engaged in internal hydrogen bonding interactions. 84 designs over the 6-12 residue size range cross membranes with an apparent permeability greater than 1 × 10-6 cm/s. Designs with exposed NH groups can be made membrane permeable through the design of an alternative isoenergetic fully hydrogen-bonded state favored in the lipid membrane. The ability to robustly design membrane-permeable and orally bioavailable peptides with high structural accuracy should contribute to the next generation of designed macrocycle therapeutics.


Assuntos
Amidas , Peptídeos , Amidas/química , Hidrogênio , Ligação de Hidrogênio , Lipídeos , Peptídeos/química
2.
Angew Chem Int Ed Engl ; 63(21): e202320045, 2024 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-38529717

RESUMO

In the realm of high-throughput screening (HTS), macrocyclic peptide libraries traditionally necessitate decoding tags, essential for both library synthesis and identifying hit peptide sequences post-screening. Our innovation introduces a tag-free technology platform for synthesizing cyclic peptide libraries in solution and facilitates screening against biological targets to identify peptide binders through unconventional intramolecular CyClick and DeClick chemistries (CCDC) discovered through our research. This combination allows for the synthesis of diverse cyclic peptide libraries, the incorporation of various amino acids, and facile linearization and decoding of cyclic peptide binder sequences. Our sensitivity-enhancing derivatization method, utilized in tandem with nano LC-MS/MS, enables the sequencing of peptides even at exceedingly low picomolar concentrations. Employing our technology platform, we have successfully unearthed novel cyclic peptide binders against a monoclonal antibody and the first cyclic peptide binder of HIV capsid protein responsible for viral infections as validated by microscale thermal shift assays (TSA), biolayer interferometry (BLI) and functional assays.


Assuntos
Biblioteca de Peptídeos , Peptídeos Cíclicos , Peptídeos Cíclicos/química , Peptídeos Cíclicos/síntese química , Ensaios de Triagem em Larga Escala , Espectrometria de Massas em Tandem
3.
Nature ; 538(7625): 329-335, 2016 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-27626386

RESUMO

Naturally occurring, pharmacologically active peptides constrained with covalent crosslinks generally have shapes that have evolved to fit precisely into binding pockets on their targets. Such peptides can have excellent pharmaceutical properties, combining the stability and tissue penetration of small-molecule drugs with the specificity of much larger protein therapeutics. The ability to design constrained peptides with precisely specified tertiary structures would enable the design of shape-complementary inhibitors of arbitrary targets. Here we describe the development of computational methods for accurate de novo design of conformationally restricted peptides, and the use of these methods to design 18-47 residue, disulfide-crosslinked peptides, a subset of which are heterochiral and/or N-C backbone-cyclized. Both genetically encodable and non-canonical peptides are exceptionally stable to thermal and chemical denaturation, and 12 experimentally determined X-ray and NMR structures are nearly identical to the computational design models. The computational design methods and stable scaffolds presented here provide the basis for development of a new generation of peptide-based drugs.


Assuntos
Desenho Assistido por Computador , Desenho de Fármacos , Peptídeos/química , Peptídeos/síntese química , Estabilidade Proteica , Motivos de Aminoácidos , Cristalografia por Raios X , Ciclização , Dissulfetos/química , Temperatura Alta , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Peptídeos/genética , Peptídeos Cíclicos/química , Peptídeos Cíclicos/genética , Desnaturação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Estereoisomerismo
4.
Graefes Arch Clin Exp Ophthalmol ; 259(1): 263-268, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32734467

RESUMO

OBJECTIVES: To describe, evaluate, and identify the characteristics, prognostic factors, and visual outcomes in patients with intraocular foreign body (IOFB) in a Latin American population. METHODS: A retrospective, observational case-series of patients with a diagnosis of IOFB. Variables analyzed included age, gender, initial and final best correct visual acuity (BCVA), ocular trauma score, intraocular pressure, mechanism of injury, material and number of IOFB, zone of injury, timing of primary repair and IOFB removal, complications, and follow up. RESULTS: Sixty-one patients with IOFB were identified of which 97% were male with a mean age of 37.9 years (SD 2.16). The most common IOFB location was intravitreal (43%). IOFBs were metallic in 78%, vegetal in 3%, and other materials in 11%. Primary repair and secondary IOFB removal were performed at a mean timepoint of 3 days and 5 days, respectively. Systemic and topical antibiotics were administered to all patients. The initial BCVA was 1.62 logMAR and the final was 0.6 logMAR, which was statistically significant (Pearson's chi-squared test, p value 0.01). No cases of endophthalmitis were seen. CONCLUSION: IOFB removal can be delayed when there are no signs of infection or evidence of retinal detachment, without an increased risk of endophthalmitis and a negative impact on visual outcomes. Use of topical and systemic antibiotics appear sufficient to prevent endophthalmitis in these cases.


Assuntos
Corpos Estranhos no Olho , Ferimentos Oculares Penetrantes , Corpos Estranhos no Olho/diagnóstico , Corpos Estranhos no Olho/cirurgia , Ferimentos Oculares Penetrantes/diagnóstico , Ferimentos Oculares Penetrantes/cirurgia , Humanos , Recém-Nascido , Masculino , Estudos Retrospectivos , Centros de Traumatologia , Resultado do Tratamento , Vitrectomia
5.
Natl Med J India ; 34(4): 206-210, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35112543

RESUMO

Diabetic myonecrosis or muscle infarction (DMI), a clinicoradiological entity is an underdiagnosed complication of diabetes mellitus. It refers to spontaneous aseptic necrosis of skeletal muscles commonly of the lower limb without evidence of any large vessel disease. It presents as painful swollen limb without any external insult in patients with long-standing diabetes mellitus with other microvascular complications especially nephropathy. We present four instances of DMI in our patients who had end-stage renal disease with a varied course.


Assuntos
Diabetes Mellitus Tipo 2 , Falência Renal Crônica , Diabetes Mellitus Tipo 2/complicações , Humanos , Infarto/complicações , Infarto/etiologia , Falência Renal Crônica/complicações , Imageamento por Ressonância Magnética/efeitos adversos , Músculo Esquelético/irrigação sanguínea
6.
Retina ; 40(3): 546-551, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30576303

RESUMO

PURPOSE: To determine the results of pars plana vitrectomy for giant retinal tear detachments using transscleral diode laser retinopexy and short-term postoperative tamponade with perfluoro-n-octane (PFnO). METHODS: Twenty consecutive patients with fresh giant retinal tears were enrolled in a single-arm prospective study. One case was withdrawn for technical reasons. The remainder all underwent pars plana vitrectomy, PFnO injection, transscleral diode laser retinopexy to the edge of the giant retinal tear, and short-term postoperative heavy liquid tamponade. None of the cases had scleral buckling or lensectomy. RESULTS: Nineteen cases (18 male and 1 female) with a mean age of 41 years (range 10-69 years) were followed up for a period of 6 months. Postoperative tamponade with PFnO was maintained for a mean of 7.6 days (range 4-21 days), after which it was exchanged for sulfur hexafluoride (SF6), perfluoropropane (C3F8) gas, or balanced salt solution. Final reattachment rate was 100%, with 3 (15.7%) patients requiring additional surgery. Best-corrected visual acuity at final follow-up was 20/40 or better in 11 eyes (58%), between 20/60 and 20/200 in 7 (37%), and 20/400 in 1 (5%). CONCLUSION: In this series of acute giant retinal tears, transscleral diode laser retinopexy together with the use of PFnO for short-term postoperative tamponade achieved excellent anatomical and visual results.


Assuntos
Tamponamento Interno/métodos , Fluorocarbonos/administração & dosagem , Terapia a Laser/métodos , Lasers Semicondutores/uso terapêutico , Retina/cirurgia , Perfurações Retinianas/cirurgia , Vitrectomia/métodos , Adolescente , Adulto , Idoso , Criança , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Estudos Prospectivos , Retina/patologia , Perfurações Retinianas/diagnóstico , Esclera/cirurgia , Resultado do Tratamento , Acuidade Visual , Adulto Jovem
7.
Ann Hepatol ; 18(5): 730-735, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31175020

RESUMO

INTRODUCTION AND OBJECTIVES: AKI is known to be associated with increased risk of mortality, however limited information is available on how AKI impacts healthcare costs and resource utilization in hospitalized patients with cirrhosis. Previous studies have had variable definitions of AKI, resulting in inconsistent reporting of the true impact of AKI in patients with cirrhosis. METHODS: Data from the Nationwide Inpatient Sample (NIS) which contains data from 44 states and 4378 hospitals, accounting for over 7 million discharges were analyzed. The inclusion data were all discharges in the 2012 NIS dataset with a discharge diagnosis of cirrhosis. RESULTS: A total of 32,605 patients were included in the analysis, incidence of AKI was 12.12% in patients with cirrhosis. Crude mortality was much higher for patients with cirrhosis and AKI (14.9% vs. 1.8%, OR 9.42, p<0.001) than for patients without AKI. In addition, mean LOS was longer (8.5 vs. 4.3 days, p<0.001) and median total hospital charges were higher for patients with AKI ($43,939 vs. $22,270, p<0.001). In multivariate logistic regression, controlling for covariates and mortality risk score, sepsis, ascites and SBP were predictors of AKI. CONCLUSIONS: AKI is relatively common in hospitalized patients with cirrhosis. Presence of AKI results in significantly higher inpatient mortality as well as LOS and resource utilization. Median hospitalization cost was twice as high in AKI patients. Early identification of patients at high risk for AKI should be implemented to reduce mortality and contain costs. Prognosis could be enhanced by utilizing biomarkers which could rapidly detect AKI.


Assuntos
Injúria Renal Aguda/epidemiologia , Custos de Cuidados de Saúde , Hospitalização/economia , Pacientes Internados/estatística & dados numéricos , Cirrose Hepática/complicações , Injúria Renal Aguda/economia , Injúria Renal Aguda/etiologia , Feminino , Mortalidade Hospitalar/tendências , Humanos , Incidência , Cirrose Hepática/economia , Cirrose Hepática/epidemiologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida/tendências , Estados Unidos/epidemiologia
8.
Aust Fam Physician ; 46(6): 401-404, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28609597

RESUMO

BACKGROUND: The objective of this article was to alert general practitioners (GPs) to the increase in ocular syphilis in the context of a worsening epidemic of syphilis among men who have sex with men (MSM). METHODS: This study used a retrospective case review of ocular syphilis cases that presented to the Royal Victorian Eye and Ear Hospital from January 2015 to August 2016. RESULTS: Twelve patients (19 eyes) were identified, including 11 males. The mean age was 35 years, and seven men were identified as MSM. Two men were diagnosed with human immunodeficiency virus (HIV) infection at presentation. Blurred vision (n = 10) and/or floaters (n = 9) were the most common presenting symptoms. All patients had uveitis as the manifestation of the ocular involvement; however, redness and pain were not universally reported. DISCUSSION: GPs should be alert to the possibility of ocular syphilis at the time of syphilis diagnosis, particularly among MSM. Urgent ophthalmic referral is required if the patient is found to have new onset visual symptoms.


Assuntos
Oftalmopatias/fisiopatologia , Sífilis/diagnóstico , Sífilis/fisiopatologia , Adulto , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Oftalmopatias/complicações , Oftalmopatias/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Penicilinas/farmacologia , Penicilinas/uso terapêutico , Estudos Retrospectivos , Minorias Sexuais e de Gênero/estatística & dados numéricos , Sífilis/tratamento farmacológico , Uveíte/tratamento farmacológico
9.
Bioconjug Chem ; 27(1): 159-69, 2016 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-26630124

RESUMO

Nonspecific ligation methods have been traditionally used to chemically modify immunoglobulins. Site-specific ligation of compounds (toxins or ligands) to antibodies has become increasingly important in the fields of therapeutic antibody-drug conjugates and bispecific antibodies. In this present study, we took advantage of the reported nucleotide-binding pocket (NBP) in the Fab arms of immunoglobulins by developing indole-based, 5-fluoro-2,4-dinitrobenzene-derivatized OBOC peptide libraries for the identification of affinity elements that can be used as site-specific derivatization agents against both mono- and polyclonal antibodies. Ligation can occur at any one of the few lysine residues located at the NBP. Immunoconjugates resulting from such affinity elements can be used as therapeutics against cancer or infectious agents.


Assuntos
Imunoconjugados/química , Imunoglobulinas/química , Biblioteca de Peptídeos , Anticorpos Biespecíficos , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Compostos Azo/química , Sítios de Ligação , Biotina/química , Reagentes de Ligações Cruzadas/química , Humanos , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/metabolismo , Imunoglobulinas/metabolismo , Indóis/química , Nucleotídeos/metabolismo , Oligopeptídeos/química , Peptídeos/química , Peptídeos/metabolismo , Trastuzumab/química
10.
Liver Int ; 36(10): 1450-6, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27037497

RESUMO

BACKGROUND & AIMS: To investigate how obesity impacts inpatient mortality, length of stay (LOS) and costs in patients with cirrhosis. Obesity is a growing epidemic associated with multiple co-morbidities, increased morbidity, and a significant economic burden on healthcare. Despite the overall harmful impact of obesity, the 'obesity paradox' has been described as decreased mortality among obese vs non-obese patients in various chronic medical conditions. METHODS: Analysis of the Nationwide Inpatient Sample (NIS) for 2012, which contains data from 44 states and 4378 hospitals. Data from all cases with primary, secondary or tertiary discharge diagnosis of cirrhosis identified by International Classification of Diseases-9 code 571.2, 571.5 571.6 were included. Primary outcomes included inpatient mortality, LOS, and hospital charges. Obesity as a predictor of mortality was defined by a predetermined obesity co-morbidity variable. RESULTS: A total of 32,605 patients were included. Crude mortality was lower for obese cirrhotic patients (2.7% vs 3.5%, P = 0.02) than for non-obese cirrhotic patients. In contrast, median LOS was longer (4 vs 3 days, P < 0.001) and median hospital charges were higher for obese cirrhotic patients ($26 803 vs $23 447, P < 0.001) In multivariate logistic regression, obesity was associated with a lower risk of inpatient mortality (OR=0.73, 95%CI: 0.55-0.95, P = 0.02). CONCLUSIONS: In the acute care setting, obese patients with cirrhosis have lower mortality than non-obese patients with cirrhosis, longer hospitalizations and higher healthcare cost, providing new evidence for the obesity paradox in cirrhosis. Obese cirrhotic patients are more likely to have enhanced nutritional reserve which may play a role in survival during acute illness.


Assuntos
Preços Hospitalares , Mortalidade Hospitalar , Tempo de Internação , Cirrose Hepática/mortalidade , Obesidade/complicações , Comorbidade , Bases de Dados Factuais , Feminino , Custos de Cuidados de Saúde , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Retrospectivos , Fatores de Risco , Estados Unidos
11.
Clin Exp Nephrol ; 20(2): 273-83, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26351173

RESUMO

BACKGROUND: We performed a discovery phase of urinary proteomic profile in children with idiopathic nephrotic syndrome and validated selected biomarkers. METHODS: Urinary proteomic profile was performed using isobaric tags for relative and absolute quantitation labeling, coupled with liquid chromatography-matrix assisted laser desorption and ionization analysis. Validation of biomarkers apolipoprotein A1, alpha 2 macroglobulin, orosomucoid 2, retinol binding protein 4 and leucine-rich alpha 2-glycoprotein 1 was done by enzyme-linked immunosorbent assay. RESULTS: Apolipoprotein A1 levels of <0.48 µg/mg of creatinine-differentiated steroid-resistant nephrotic syndrome (SRNS) from first episode nephrotic syndrome, area under curve (AUC) [0.99 (CI 0.9-1.0), 100 % sensitivity and 100 % specificity] and a value of <0.24 µg/mg of creatinine could differentiate SRNS from frequently relapsing nephrotic syndrome/steroid dependent nephrotic syndrome [AUC 0.99 (CI 0.9-1.0), 100 % sensitivity and 100 % specificity]. Alpha 2 macroglobulin could differentiate children with SRNS-focal segmental glomerulosclerosis (FSGS) from SRNS-minimal change disease (MCD) at values >3.3 µg/mg of creatinine [AUC 0.84 (CI 0.62-1.0), 90 % sensitivity and 85 % specificity]. Orosomucoid 2 >1.81 µg/mg of creatinine could distinguish SRNS-FSGS from SRNS-MCD [AUC 0.84 (CI 0.62-1.0), sensitivity 90 % and specificity 85.5 %]. RBP 4 value of >1.54 µg/mg of creatinine differentiated SRNS-FSGS from SRNS-MCD [AUC 0.87 (CI 0.68-1.0), sensitivity 90 % and specificity 85.7 %]. CONCLUSIONS: Lower level of apolipoprotein A1 in urine is suggestive of SRNS. Alpha 2 macroglobulin, retinol binding protein 4 and orosomucoid 2 are markers associated with FSGS, with alpha 2 macroglobulin being most predictive.


Assuntos
Biomarcadores/urina , Síndrome Nefrótica/congênito , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Síndrome Nefrótica/urina
12.
Sci Total Environ ; 951: 175595, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39154992

RESUMO

For accurate and reliable analysis of microplastics (MPs) in wastewater (WW), it is imperative to comprehend the significance of pre-treating WW before analysis. The suspended solids (SS) in the matrix tend to adhere to the MPs during filtration, which interferes with the detection of the MPs. In this regard, the present study aims to develop and optimize a pretreatment method to improve the extraction efficiency of MPs from WW by reducing the SS. A combination of the Fenton reaction and ultrasonication, ferro-sonication (Fe-UlS), was proposed to digest and eliminate the SS from WW. This hybrid pretreatment, Fe-UlS, was optimized for ultrasonication amplitude, treatment time, and hydrogen peroxide dose using response surface methodology (RSM) with a Box-Behnken design, achieving a desirability of 0.984. The optimum conditions for the Fe-UlS, such as the (1:1) Fenton reagent ratio (0.05 M FeSO4: 30 % H2O2), ultrasonication amplitude (31 %), and total process time (30 min) were found to be statistically significant (p < 0.05). The developed method was then employed for the extraction of spiked polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) MPs in real WW and found efficient in removing 83 % of the TSS present in the primary influent were in 30 min at a temperature of 45 °C. Also, the method did not affect the physio-chemical characteristics of the MPs; however, the thermal analysis of PE and PP MPs showed a statistically significant decrease in the melting temperature, as proven by paired t-test analysis. Further, a non-targeted liquid chromatography-mass spectrometry (LC-MS) analysis proved that Fe-UlS is a stable process, as it did not cause any leaching of MPs under the optimum pretreatment conditions. Finally, Laser Direct-Infrared Imaging (LD-IR) analysis was conducted to validate the developed Fe-UlS pretreatment approach for MP analysis in real WW. About 3434 MPs were detected in 100 mL of WW primary influent, within the size range of 9 to 500 µm. This hybrid pretreatment approach not only streamlines WW sample processing but also reduces the required concentration of Fenton reagent and processing time, yielding accurate and reliable results for monitoring MPs in WW.

13.
J Pediatr Ophthalmol Strabismus ; : 1-15, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39254187

RESUMO

PURPOSE: To evaluate the effect of the EYEPORT II vision training system (Bernell) on accommodation in cases of accommodative insufficiency. METHODS: The experimental study was conducted in a binocular vision clinic. Of 230 patients, 36 were eligible and willing to participate in office-based therapy. Participants were randomly divided into two groups: control and EYEPORT. The control group received conventional therapy and the EYEPORT group received conventional therapy combined with the EYEPORT II vision training device. The therapy lasted for 1 hour daily over 6 days in a week, with 24 sessions administered over 4 weeks. Accommodative parameters were reevaluated 2 weeks, 4 weeks, and 3 months after treatment. RESULTS: The study included 19 men and 17 women, with a median age of 27.50 years. After 24 sessions of vision therapy, accommodative parameters improved significantly, with more pronounced results compared with baseline measurements, as demonstrated by the Wilcoxon signed-rank test (P < .05). The Mann-Whitney U test indicated a significant (P < .05) improvement in treatment outcomes for the EYEPORT group using the EYEPORT device together with conventional therapy. The median accommodation amplitude increased by 6.95 diopters (D), the accommodation lag decreased by -0.25 D, the positive relative accommodation improved by -1.63 D, and the accommodative facility increased by 13 cycles/minute. After 3 months without therapy, the treatment outcome was maintained. CONCLUSIONS: Office-based vision therapy can effectively treat accommodative insufficiency. Both groups showed improvement in the accommodative amplitude and other parameters. The EYEPORT group was more stable at 3 months. [J Pediatr Ophthalmol Strabismus. 20XX;XX(X):XXX-XXX.].

14.
Microbiol Res ; 287: 127840, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39032267

RESUMO

Rhodosporidium toruloides has emerged as an excellent option for microbial lipid production due to its ability to accumulate up to 70 % of lipids per cell dry weight, consume multiple substrates such as glucose and xylose, and tolerate toxic compounds. Despite the potential of Rhodosporidium toruloides for high lipid yields, achieving these remains is a significant hurdle. A comprehensive review is essential to thoroughly evaluate the advancements in processes and technologies to enhance lipid production in R. toruloides. The review covers various strategies for enhancing lipid production like co-culture, adaptive evolution, carbon flux analysis, as well as different modes of fermentation. This review will help researchers to better understand the recent developments in technologies for sustainable and scalable lipid production from R. toruloides and simultaneously emphasize the need for developing an efficient and sustainable bioprocess.


Assuntos
Fermentação , Metabolismo dos Lipídeos , Lipídeos , Rhodotorula , Lipídeos/biossíntese , Rhodotorula/metabolismo , Técnicas de Cocultura , Glucose/metabolismo , Xilose/metabolismo
15.
Science ; 384(6694): 420-428, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38662830

RESUMO

Small macrocycles with four or fewer amino acids are among the most potent natural products known, but there is currently no way to systematically generate such compounds. We describe a computational method for identifying ordered macrocycles composed of alpha, beta, gamma, and 17 other amino acid backbone chemistries, which we used to predict 14.9 million closed cycles composed of >42,000 monomer combinations. We chemically synthesized 18 macrocycles predicted to adopt single low-energy states and determined their x-ray or nuclear magnetic resonance structures; 15 of these were very close to the design models. We illustrate the therapeutic potential of these macrocycle designs by developing selective inhibitors of three protein targets of current interest. By opening up a vast space of readily synthesizable drug-like macrocycles, our results should considerably enhance structure-based drug design.


Assuntos
Amidas , Aminoácidos , Produtos Biológicos , Desenho de Fármacos , Peptídeos Cíclicos , Amidas/química , Aminoácidos/química , Produtos Biológicos/síntese química , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Cristalografia por Raios X , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Conformação Molecular , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacologia
16.
ACS Chem Biol ; 19(5): 1125-1130, 2024 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-38712757

RESUMO

There remains a critical need for new antibiotics against multi-drug-resistant Gram-negative bacteria, a major global threat that continues to impact mortality rates. Lipoprotein signal peptidase II is an essential enzyme in the lipoprotein biosynthetic pathway of Gram-negative bacteria, making it an attractive target for antibacterial drug discovery. Although natural inhibitors of LspA have been identified, such as the cyclic depsipeptide globomycin, poor stability and production difficulties limit their use in a clinical setting. We harness computational design to generate stable de novo cyclic peptide analogues of globomycin. Only 12 peptides needed to be synthesized and tested to yield potent inhibitors, avoiding costly preparation of large libraries and screening campaigns. The most potent analogues showed comparable or better antimicrobial activity than globomycin in microdilution assays against ESKAPE-E pathogens. This work highlights computational design as a general strategy to combat antibiotic resistance.


Assuntos
Antibacterianos , Desenho de Fármacos , Peptídeos Cíclicos , Peptídeos Cíclicos/farmacologia , Peptídeos Cíclicos/química , Peptídeos Cíclicos/síntese química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Testes de Sensibilidade Microbiana , Depsipeptídeos/farmacologia , Depsipeptídeos/química , Lipoproteínas/química , Lipoproteínas/metabolismo , Lipoproteínas/farmacologia , Lipoproteínas/antagonistas & inibidores , Proteínas de Bactérias , Peptídeos , Ácido Aspártico Endopeptidases
17.
BMC Genomics ; 14: 240, 2013 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-23574621

RESUMO

BACKGROUND: The recA/RAD51 gene family encodes a diverse set of recombinase proteins that affect homologous recombination, DNA-repair, and genome stability. The recA gene family is expressed across all three domains of life - Eubacteria, Archaea, and Eukaryotes - and even in some viruses. To date, efforts to resolve the deep evolutionary origins of this ancient protein family have been hindered by the high sequence divergence between paralogous groups (i.e. ~30% average pairwise identity). RESULTS: Through large taxon sampling and the use of a phylogenetic algorithm designed for inferring evolutionary events in highly divergent paralogs, we obtained a robust, parsimonious and more refined phylogenetic history of the recA/RAD51 superfamily. CONCLUSIONS: In summary, our model for the evolution of recA/RAD51 family provides a better understanding of the ancient origin of recA proteins and the multiple events that lead to the diversification of recA homologs in eukaryotes, including the discovery of additional RAD51 sub-families.


Assuntos
Biologia Computacional , Evolução Molecular , Filogenia , Rad51 Recombinase/metabolismo , Recombinases Rec A/metabolismo , Rad51 Recombinase/genética , Recombinases Rec A/genética
18.
Clin Exp Ophthalmol ; 41(5): 450-4, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23078284

RESUMO

BACKGROUND: To assess the efficacy of 'Judders' as a technique reflecting adequacy of removal of ophthalmic viscoelastic device in cataract surgery. DESIGN: Prospective, consecutive, single surgeon study. PARTICIPANTS: Cohort of 223 patients undergoing phacoemulsification. METHODS: 'Judders' are periodic, abrupt, horizontal displacements of the intraocular lens causing balanced salt solution to displace retropseudophakic ophthalmic viscoelastic device. The number of 'Judders' was correlated with axial length, anterior chamber depth, and preoperative and postoperative intraocular pressure. MAIN OUTCOME MEASURES: Number of 'Judders', axial length, anterior chamber depth, day 1 postoperative intraocular pressure. RESULTS: The mean number of 'Judders' was 3.2. There was a positive association between the number of 'Judders' and axial length, but not between number of 'Judders' and anterior chamber depth. Mean preoperative intraocular pressure was 14.5 mmHg; mean day 1 postoperative intraocular pressure was 15.6 mmHg. Intraocular pressure rose in 47% of cases. In six cases (5%), intraocular pressure rose greater than 10 mmHg (range 11-23 mmHg) from the preoperative level. CONCLUSIONS: Aspirating ophthalmic viscoelastic device with the irrigation/aspiration tip posterior to the intraocular lens may be associated with the risk of a posterior capsule tear. Maintaining the irrigation/aspiration tip anterior to the intraocular lens may offer a significant safety advantage. The number of 'Judders', usually 3-4, appears to be a safe and reliable end-point of complete ophthalmic viscoelastic device removal. There were significantly more 'Judders' in eyes with a longer axial length. The safety and efficacy of 'Judders' are reflected by the stable mean postoperative intraocular pressure.


Assuntos
Ácido Hialurônico/metabolismo , Implante de Lente Intraocular , Facoemulsificação/métodos , Ruptura da Cápsula Posterior do Olho/prevenção & controle , Sucção/métodos , Irrigação Terapêutica/métodos , Viscossuplementos/metabolismo , Idoso , Câmara Anterior/anatomia & histologia , Comprimento Axial do Olho/anatomia & histologia , Biometria , Feminino , Humanos , Pressão Intraocular/fisiologia , Masculino , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos , Acuidade Visual/fisiologia
19.
Br Ir Orthopt J ; 19(1): 78-84, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37780187

RESUMO

Background: Positive fusional vergence (PFV) is vital in maintaining fusion in critical and continuous near tasks such as reading or performing digital screen tasks. This study investigated how PFV changed under various lighting conditions. Methods: This cross-sectional study recruited 34 participants aged between 21 and 25 years, with best corrected visual acuity (BCVA) 0.0 logMAR and insignificant refractive error. Three different illuminations-low illumination (50 lux), medium lighting (100 lux), and high illumination (150 lux)-were used to examine the ocular parameters PFV (blur, break, and recovery points), contrast sensitivity and pupil diameter. Results: Pupil diameter changed significantly in different room illuminations (p = 0.00). There was no significant difference in contrast sensitivity across the three levels of room illumination (p = 0.368). Mean PFV (SD) (blur) was 14.5 (2.5) in 50 lux, 10.2 (2.2) in 100 lux, and 8.2 (2.1) in 150 lux. Under 50, 100 and 150 lux, respectively, the mean PFV (SD) (break) values were 16.7 (2.4), 13.4 (1.8), and 10.8 (2.2), and the mean PFV (SD) (recovery) values were 13.3 (2.1), 10.7 (2.1), and 7.5 (2.7). With increased illumination levels, PFV blur, break, and recovery values were significantly lower (p < 0.001). Conclusions: PFV values were significantly higher in lower illumination. Clinicians should be aware that room illumination affected the PFV values measured.

20.
Eur J Ophthalmol ; 33(3): 1273-1286, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36384286

RESUMO

This article is about the accommodation spasm. The primary rule for near vision is ciliary muscle constriction, synchronised convergence of both eyes, and pupil constriction. Any weaknesses in these components could result in an accommodative spasm. Variable retinoscopic reflex, unstable refractive error, and lead of accommodation in near retinoscopy are common causes of spasm. We conducted a thorough literature search in the PubMed and Google Scholar databases for published journals prior to June 2022, with no data limitations. This review contains twenty-eight case reports, six cohort studies, four book references, four review articles, and two comparative studies after applying the inclusion and exclusion criteria. The majority of studies looked at accommodative spasm, near reflex spasm, and pseudomyopia. The most common causes of accommodative spasm are excessive close work, emotional distress, head injury, and strabismus. Despite side effects or an insufficient regimen, cycloplegic drops are effective in diagnosing accommodation spasm. The modified optical fogging technique is also effective and may be an option for treating accommodative spasm symptoms. Bifocals for near work, manifest refraction, base-in prisms, and vision therapy are some of the other management options. As a result, it requires a comprehensive clinical treatment strategy. This review aims to investigate the various aetiology and treatments responsible for accommodative spasm and proposes widely implementing the modified optical fogging method and vision therapy in clinics as comprehensive management to reduce the future upward trend of accommodative spasm.


Assuntos
Miopia , Erros de Refração , Baixa Visão , Humanos , Acomodação Ocular , Espasmo/diagnóstico , Espasmo/terapia , Espasmo/etiologia , Miopia/etiologia , Midriáticos/uso terapêutico , Baixa Visão/complicações
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