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Most insertions or deletions generated by CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) endonucleases are short (<25 bp), but unpredictable on-target long DNA deletions (>500 bp) can be observed. The possibility of generating long on-target DNA deletions poses safety risks to somatic genome editing and makes the outcomes of genome editing less predictable. Methods for generating refined mutations are desirable but currently unavailable. Here, we show that fusing Escherichia coli DNA polymerase I or the Klenow fragment to Cas9 greatly increases the frequencies of 1-bp deletions and decreases >1-bp deletions or insertions. Importantly, doing so also greatly decreases the generation of long deletions, including those >2 kb. In addition, templated insertions (the insertion of the nucleotide 4 nt upstream of the protospacer adjacent motif) were increased relative to other insertions. Counteracting DNA resection was one of the mechanisms perturbing deletion sizes. Targeting DNA polymerase to double-strand breaks did not increase off-targets or base substitution rates around the cleavage sites, yet increased editing efficiency in primary cells. Our strategy makes it possible to generate refined DNA mutations for improved safety without sacrificing efficiency of genome editing.
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Sistemas CRISPR-Cas , Edição de Genes , Proteína 9 Associada à CRISPR/genética , Proteína 9 Associada à CRISPR/metabolismo , DNA/genética , DNA/metabolismo , DNA Polimerase Dirigida por DNA/metabolismo , Edição de Genes/métodosRESUMO
INTRODUCTION: Even though IL-6 and MMP-9 are associated with airway inflammation in asthma, there is paucity of data in Indian population. OBJECTIVE: To determine the levels of IL-6 and MMP-9 in the serum of patients suffering from asthma, and correlate with (a) disease severity, as per GINA guidelines; (b) clinical phenotypes; and (c) response to treatment. METHODOLOGY: The levels of IL-6 and MMP-9 were compared between moderate persistent asthma (n = 25), severe persistent asthma (n = 25) and normal controls (n = 30). IL-6 and MMP-9 were measured by ELISA (R&D Systems Inc., USA and Canada) and compared between controls and asthmatics and between groups of different asthma severity, clinical variables, spirometry, and allergen sensitization. Spirometry was repeated after 2 months of ICS+LABA to assess response to treatment in relation to baseline IL-6 and MMP-9 levels. RESULTS: We observed a significant difference in both IL-6 and MMP-9 levels among asthmatics versus controls (p < 0.001), moderate versus severe persistent asthma (p < 0.001). A significant negative correlation was observed between MMP-9 and pre-bronchodilator FEV1 and FVC, but not with IL-6. There was no association between IL-6 and MMP-9 with asthma duration, total IgE, AEC, number of allergens sensitized and degree of sensitization. No significant correlation (p > 0.5) was observed with IL-6 and MMP-9 levels and FEV1 improvement after 2 months of ICS+LABA. CONCLUSION: Higher levels of IL-6 and MMP-9 were observed in asthmatics as compared to controls and in severe persistent asthma as compared to moderate persistent asthma, higher levels of MMP-9 was associated with lower lung functions.
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Asma/imunologia , Mediadores da Inflamação/sangue , Interleucina-6/sangue , Metaloproteinase 9 da Matriz/sangue , Adulto , Asma/sangue , Biomarcadores , Índice de Massa Corporal , Canadá , Estudos de Casos e Controles , Feminino , Humanos , Hipersensibilidade/sangue , Imunoglobulina E/sangue , Índia , Masculino , Pessoa de Meia-Idade , Testes de Função Respiratória , Índice de Gravidade de DoençaRESUMO
BACKGROUND: Flow diversion is a novel method of therapy wherein an endoluminal sleeve, the flow diverter stent is placed across the neck of complex aneurysms to curatively reconstruct abnormal vasculature. We present the first Indian single center experience with the pipeline embolization device (PED) and 6 months follow-up results of 5 patients. SUBJECTS AND METHODS: Five complex or recurrent intracranial aneurysms in five patients were treated with PED. The patients were followed-up with magnetic resonance angiography (MRA) after 4 weeks and conventional angiography after 6 months. Feasibility, complications, clinical outcome, early 1-month MRA and 6 months conventional angiographic follow-up results were analyzed. RESULTS: Of the five aneurysms treated, four were in the anterior circulation and one in the posterior circulation. All five patients were treated with a single PED in each, and additionally coils were used in one patient. At 1-month MRA follow-up, complete occlusion was seen in 2 (40%) of the five cases. Post 6 months conventional angiography showed complete occlusion of the aneurysm sac in all five cases (100%). Side branch ostia were covered in three patients, all of which were patent (100%). There was no incidence of major neurological morbidity or mortality. One patient (20%) who had basilar top aneurysm experienced minor neurological disability after 5 days which partially improved. CONCLUSIONS: Pipeline embolization device for complex and recurrent aneurysms is technically feasible, safe, offers low complication rate, and definitive vascular reconstruction. PED can be used without fear of occlusion of covered eloquent side branches and perforators.
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Embolização Terapêutica/instrumentação , Embolização Terapêutica/métodos , Aneurisma Intracraniano/terapia , Stents , Adulto , Idoso , Angiografia Digital , Feminino , Humanos , Índia , Aneurisma Intracraniano/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
Background: Peripherally inserted central catheters (PICCs) are central venous catheters inserted peripherally but terminate in great vessels. PICCs are widely used for patients requiring long-term intravenous therapy in both in-patient and out-patient settings. Aim: This study was carried out to understand PICC-related complications, specifically infections and causal pathogens, in a tertiary care hospital in Kerala, South India. Methods: A retrospective analysis of PICC insertions and follow-up during a 9 years period to look at patient demographics and infections related to PICC was carried out. Results: The overall PICC-related complication rate is 28.1% (4.98 per 1000 PICC days). Commonest complication was thrombosis followed by infection, either PICC-associated bloodstream infection (PABSI) or local infection (LI). PABSI noted in this study was 1.34 per 1000 catheter days. The majority (85%) of PABSI were due to Gram-negative rods. The average duration of PICC days for occurrence of PABSI was 14 days and the majority occurred in in-patients. Conclusion: Thrombosis and infection were the commonest PICC-related complications. PABSI rate was comparable to that of previous studies.
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Type 1 Dent disease is caused by changes in chloride voltage-gated channel 5 (CLCN5) gene on chromosome X, which causes the lack or dysfunction of chloride channel ClC-5. Affected subjects show proteinuria and hypercalciuria, and eventually develop end-stage kidney disease. Currently there is no cure for this disease. Here, we used CRISPR-Cas9 technology to develop a Clcn5 mouse model with 95% of the ClC-5 coding region deleted. These mutant mice showed obvious Dent disease-like phenotypes. We used lentiviral vectors to deliver human CLCN5 cDNA into the kidneys of mutant mice by retrograde ureter injection and observed increased megalin expression, improved diuresis, and decreased urinary calcium and protein excretion, which persisted for 3 months. The therapeutic effects diminished 4 months after gene therapy. Our data suggest that immune responses to the transgene products most likely explain the loss of gene therapy effects. This study suggests that gene therapy could be a promising approach to treat Dent disease, but more work is needed to achieve sustained therapeutic effects.
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INTRODUCTION: Periodontitis causes oxidative stress and reduce total antioxidant levels. The aim of this study was to determine the effect of non-surgical periodontal treatment on leptin levels and total antioxidant capacity in chronic periodontitis. MATERIALS AND METHODS: A total of 35 chronic periodontitis (ChP) patients and 35 systemically and periodontal healthy subjects were enrolled in this study. Further, the ChP group received nonsurgical periodontal therapy (NSPT). Leptin and total antioxidant capacity (TAOC) was measured in serum and saliva samples at baseline, 3 months and 6 months after non-surgical periodontal therapy. Clinical parameters measured were measured at baseline, 1, 3 and 6 months interval. RESULTS: The mean serum leptin and TAOC levels in control group were significantly higher compared to chronic periodontitis group (p < 0.05). The control group had lower mean salivary leptin levels and higher mean salivary TAOC levels as compared to periodontitis group(p < 0.05). Clinical parameters were improved in ChP group post therapy (p < 0.05). However, the periodontal treatment showed insignificant changes in serum and salivary leptin and TAOC levels. CONCLUSION: Chronic periodontitis is significantly associated with serum and salivary TAOC and leptin levels. Non surgical periodontal therapy didn't alter the local and systemic TAOC and leptin levels.
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Transient delivery of CRISPR-based genome editing effectors is important to reduce off-target effects and immune responses. Recently extracellular vesicles (EVs) have been explored for Cas9 ribonucleoprotein (RNP) delivery. However, lack of mechanisms to enrich RNPs into EVs limited the efficiency of EVs as a RNP delivery vehicle. Here we describe a mechanism to actively enrich RNPs into EVs. We used the specific interaction between RNA aptamer and aptamer-binding protein (ABP) to enrich RNPs into EVs. We inserted RNA aptamer com into single guide RNA (sgRNA), and fused com-binding ABP Com to both termini of tetraspan protein CD63 that is abundant in exosomes. We found that the Com/com interaction enriched Cas9 and adenine base editor (ABE) RNPs into EVs, via forming a three-component complex including CD63-Com fusion protein, com-modified sgRNA and Cas9 or ABE. The RNP enriched EVs are efficient in genome editing and transiently expressed. The system is capable of delivering RNPs targeting multiple loci for multiplex genome editing. In addition, Cas9 from different species can be used together. The EV-delivered RNPs are active in vivo. The data show that the aptamer and ABP interactions can be utilized to actively enrich RNPs into EVs for improved genome editing efficiency and safety.
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Engenharia Celular , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Vesículas Extracelulares , Edição de Genes/métodos , Veículos Farmacêuticos , Ribonucleoproteínas , Animais , Feminino , Células HEK293 , Humanos , Camundongos , Tetraspanina 30/genéticaRESUMO
The integration of artificial intelligence (AI) and augmented realities into the medical field is being attempted by various researchers across the globe. As a matter of fact, most of the advanced technologies utilized by medical providers today have been borrowed and extrapolated from other industries. The introduction of AI into the field of hepatology and liver surgery is relatively a recent phenomenon. The purpose of this narrative review is to highlight the different AI concepts which are currently being tried to improve the care of patients with liver diseases. We end with summarizing emerging trends and major challenges in the future development of AI in hepatology and liver surgery.
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Aortic injuries are notoriously lethal, particularly when associated with concomitant injuries. We describe the evaluation and management of a polytrauma patient with transverse arch transection that was complicated by dissection of both common carotid arteries. He was managed with aortic arch replacement and reimplanatation of the innominate and left common carotid arteries with an additional graft from the ascending aorta to the right common carotid artery.
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Aorta Torácica/lesões , Aorta Torácica/cirurgia , Lesões das Artérias Carótidas/cirurgia , Traumatismo Múltiplo/cirurgia , Adolescente , Humanos , MasculinoRESUMO
Most Duchenne muscular dystrophy (DMD) cases are caused by deletions or duplications of one or more exons that disrupt the reading frame of DMD mRNA. Restoring the reading frame allows the production of partially functional dystrophin proteins, and result in less severe symptoms. Antisense oligonucleotide mediated exon skipping has been approved for DMD, but this strategy needs repeated treatment. CRISPR/Cas9 can also restore dystrophin reading frame. Although recent in vivo studies showed the efficacy of the single-cut reframing/exon skipping strategy, methods to find the most efficient single-cut sgRNAs for a specific mutation are lacking. Here we show that the insertion/deletion (INDEL) generating efficiency and the INDEL profiles both contribute to the reading frame restoring efficiency of a single-cut sgRNA, thus assays only examining INDEL frequency are not able to find the best sgRNAs. We therefore developed a GFP-reporter assay to evaluate single-cut reframing efficiency, reporting the combined effects of both aspects. We show that the GFP-reporter assay can reliably predict the performance of sgRNAs in myoblasts. This GFP-reporter assay makes it possible to efficiently and reliably find the most efficient single-cut sgRNA for restoring dystrophin expression.
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Éxons/genética , Terapia Genética/métodos , Distrofia Muscular de Duchenne/genética , Fases de Leitura/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Distrofina/genética , Distrofina/metabolismo , Genes Reporter/genética , Humanos , Mutação INDEL/genética , Distrofia Muscular de Duchenne/metabolismo , Oligonucleotídeos Antissenso/metabolismo , RNA Mensageiro/genéticaRESUMO
Lower extremity arteries play vital role of supplying blood to the extremity bone, muscles, tendons and nerves to maintain the mobility of the body. These arteries may get involved with a number of disease processes which restrict the optimal functioning of the limb. The knowledge of various diseases, clinical presentation, appearance on various imaging modalities and segments of involvement helps one to clinch the diagnosis. It is of paramount importance for imaging clinician to apply the correct imaging tool based on the clinical question which is facilitated by know how of the advantages and limitation of each of these imaging modalities. This article focuses on lower extremity arteries, its anatomy, various imaging modalities and common disease conditions affecting the lower limb arteries.
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Esterases are an important group of biocatalysts for synthetic organic chemistry. Functional metagenomics allows discovery of novel biocatalysts by providing access to the gene pool of the microbial community of a habitat. Two metagenomic libraries representing the gene pool of sea sediment and hot spring microbial mat were constructed. Functional screening of these libraries resulted in the isolation of total 8 clones with tributyrin hydrolytic activity. Sequence analysis revealed 10 putative lipolytic proteins with 42-99% homology to the protein sequences in the databases, nine of which represented six known esterase families. Four of the encoded proteins represented Family V and amongst others, one each represented the Family VIII, pectin acetylesterase, enterobactin esterase, G-D-S-L family and OsmC domain containing esterase. One unusual lipolytic protein possessed poly-(3-hydroxybutyrate) depolymerase domain fused to lipase/esterase domain. Two phylogenetically related esterases (MLC3 and SLC5) belonging to family V were expressed and purified to homogeneity. The enzymes exhibited environment-adapted temperature optimum and thermostability. MLC3 was able to stereoselectively hydrolyze R-methyl mandelate to produce R-mandelic acid, an important chiral building block, which suggests MLC3 has potential commercial application.
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Esterases/metabolismo , Sedimentos Geológicos/microbiologia , Fontes Termais/microbiologia , Metagenoma , Estabilidade Enzimática , Esterases/química , Filogenia , Alinhamento de Sequência , Estereoisomerismo , Especificidade por Substrato , TemperaturaRESUMO
BACKGROUND: Technological advancement in medical science is constantly innovating solutions to the varied and complex challenges of surgery. Digital diagnostics and prospective microsurgery are rapidly evolving. Three-dimensional (3-D) imagery and computed tomography (CT) scanning can determine accurate dimensions of many defects. Subsequently, a thorough understanding of micro-vasculature and application of microsurgical techniques allows modelling of flaps to obtain an accurate transplant resulting in an aesthetic outcome following the very first operation. METHODS: Two patients with Parry-Romberg syndrome and one patient with haemifacial microsomia (Goldenhar syndrome) were treated with anterolateral thigh (ALT) flaps to restore facial volume, contour, and symmetry. In each case, a different approach in planning and performing the intervention was applied:The patient in the first case had a full-thickness ALT flap transplant with significant overcorrection.The patient in the second case had reconstruction with a partially thinned ALT flap guided by a clinically formed template made per manual measurements.The patient in the third case had reconstruction with a precise primary thinned ALT flap with a template made according to data obtained from superimposed 3-D photographs and CT scans. RESULTS: All flaps survived. In cases 1 and 2, a corrective intervention was required to achieve acceptable facial symmetry. In case 3, a very good aesthetic result was achieved immediately after the first operation. CONCLUSIONS: Digital methods of 3-D analysis offer great opportunities in creating a precise operative plan, and modern surgical techniques make it feasible to implement it intra-operatively. Overall, these methods shortened the rehabilitation time by avoiding further revision surgeries.
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Amyloidosis is a multi-systemic diffusely infiltrating disease due to extracellular deposition of protein-mucopolysaccharide complexes. The type of protein deposited determines the subgroup of amyloid. Hepatic amyloidosis is a rare infiltrating disease affecting the hepatic parenchyma. A wide range of clinical presentation and atypical imaging findings delay the diagnosis of amyloidosis, while tissue biopsy demonstrating amyloid deposits is vital for a definitive diagnosis.