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1.
Curr Cardiol Rep ; 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38568339

RESUMEN

PURPOSE OF REVIEW: Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder in women of reproductive age. It has been associated with metabolic, reproductive, and psychiatric disorders. Despite its association with insulin resistance (IR) and cardiovascular disease (CVD) risk factors, the association between PCOS and CVD outcomes has been conflicting. This review reports the updated evidence between PCOS, insulin resistance, and CVD events. RECENT FINDINGS: IR is highly prevalent occurring in 50 to 95% of general and obese PCOS women. The etiology of PCOS involves IR and hyperandrogenism, which lead to CVD risk factors, subclinical CVD, and CVD outcomes. Multiple studies including meta-analysis confirmed a strong association between PCOS and CVD events including ischemic heart disease, stroke, atrial fibrillation, and diabetes, particularly among premenopausal women, and these associations were mediated by metabolic abnormalities. PCOS is highly familial and has substantial CVD risk and transgenerational effects regardless of obesity. A personalized approach to the CVD risk assessment and management of symptom manifestations should be conducted according to its phenotypes. Lifestyle modifications and reduction in environmental stressors should be encouraged for CVD prevention among PCOS women.

2.
Indian J Surg Oncol ; 15(1): 8-11, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38511042

RESUMEN

Breast cancer patients with HER2 gene amplification as assessed by FISH are eligible for HER2-targeted therapy. However, in a small subset of patients, unusual FISH pattern of co-localization and co-amplification can pose challenges in interpretation of the HER2 status and hence to assess the HER2 status accurately; our aim was to report their incidence and analyze them based on latest ASCO/CAP 2018 guidelines. We present seven cases with HER2/CEP17 co-amplification and co-localization from a total 4040 cases referred during the year 2017 to 2021 at Mumbai Reference Laboratory, SRL Diagnostics. Core needle biopsy/excision invasive breast carcinoma specimens from metastatic sites were tested for IHC for expressions of ER, PR, and HER2. The ones which came equivocal on HER2 IHC were then evaluated for HER2 amplification by FISH. Co-amplification and co-localization of HER2 and centromeric 17 was observed with a frequency of 0.1% that falls in the range of 0.5-0.1% as reported from other large-scale studies. Our study showed that implementation of a binary inhouse concurrent assessment with IHC as per the ASCO/CAP 2018 helps to reach the most definitive and accurate HER2 status. Our study is an attempt to report such challenging FISH patterns and their work-up for a better understanding on the interpretation. Cumulative data along with follow-up in these cases would bring an insight into exact therapeutic outcome.

4.
Cell ; 186(23): 5135-5150.e28, 2023 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-37865090

RESUMEN

Mycobacterium tuberculosis (Mtb) cultured axenically without detergent forms biofilm-like cords, a clinical identifier of virulence. In lung-on-chip (LoC) and mouse models, cords in alveolar cells contribute to suppression of innate immune signaling via nuclear compression. Thereafter, extracellular cords cause contact-dependent phagocyte death but grow intercellularly between epithelial cells. The absence of these mechanopathological mechanisms explains the greater proportion of alveolar lesions with increased immune infiltration and dissemination defects in cording-deficient Mtb infections. Compression of Mtb lipid monolayers induces a phase transition that enables mechanical energy storage. Agent-based simulations demonstrate that the increased energy storage capacity is sufficient for the formation of cords that maintain structural integrity despite mechanical perturbation. Bacteria in cords remain translationally active despite antibiotic exposure and regrow rapidly upon cessation of treatment. This study provides a conceptual framework for the biophysics and function in tuberculosis infection and therapy of cord architectures independent of mechanisms ascribed to single bacteria.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Animales , Ratones , Biopelículas , Pulmón/microbiología , Pulmón/patología , Mycobacterium tuberculosis/fisiología , Tuberculosis/microbiología , Tuberculosis/patología , Virulencia , Fenómenos Biomecánicos
5.
Natl Acad Sci Lett ; : 1-8, 2023 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-37363281

RESUMEN

To determine the cardiopulmonary changes in the survivors of acute COVID-19 infection at 3-6 month and 6-12 month. We followed up 53 patients out of which 28 (52%) had mild COVID-19 and 25 (48%) had severe COVID-19. The first follow-up was between 3 month after diagnosis up to 6 month and second follow-up between 6 and 12 month from the date of diagnosis of acute COVID-19. They were monitored using vital parameters, pulmonary function tests, echocardiography and a chest computed tomography (CT) scan. We found improvement in diffusing capacity for carbon monoxide (DLCO) with a median of 52% of predicted and 80% of predicted at the first and second follow-up, respectively. There was improvement in the CTSS in severe group from 22 (18-24) to 12 (10-18; p-0.001). Multivariable logistic regression revealed increased odds of past severe disease with higher CTSS at follow-up (OR-1.7 [CI 1.14-2.77]; P = 0.01). Correlation was found between CTSS and DLCO at second follow-up (r2 = 0.36; p < 0.01). Most of patients recovered from COVID-19 but a subgroup of patients continued to have persistent radiological and pulmonary function abnormalities necessitating a structured follow-up.

6.
Acta Biomater ; 167: 135-146, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37369267

RESUMEN

Bone mineralization involves a complex orchestration of physico-chemical responses from the organism. Despite extensive studies, the detailed mechanisms of mineralization remain to be elucidated. This study aims to characterize bone mineralization using an in-vivo long bone fracture healing model in the rat. The spatio-temporal distribution of relevant elements was correlated to the deposition and maturation of hydroxyapatite and the presence of matrix remodeling compounds (MMP-13). Multi-scale measurements indicated that (i) zinc is required for both the initial mineral deposition and resorption processes during mature mineral remodeling; (ii) Zinc and MMP-13 show similar spatio-temporal trends during early mineralization; (iii) Iron acts locally and in coordination with zinc during mineralization, thus indicating novel evidence of the time-events and inter-play between the elements. These findings improve the understanding of bone mineralization by explaining the link between the different constituents of this process throughout the healing time. STATEMENT OF SIGNIFICANCE: Bone mineralization involves a complex orchestration of physico-chemical responses from the organism, the detailed mechanisms of which remain to be elucidated. This study presents a highly novel multi-scale multi-modal investigation of bone mineralization using bone fracture healing as a model system. We present original characterization of tissue mineralization, where we relate the spatio-temporal distribution of important trace elements to a key matrix remodeling compound (MMP-13), the initial deposition and maturation of hydroxyapatite and further remodeling processes. This is the first time that mineralization has been probed down to the nanometric level, and where key mineralization components have been investigated to achieve a comprehensive and mechanistic understanding of the underlying mineralization processes during bone healing.


Asunto(s)
Curación de Fractura , Minerales , Ratas , Animales , Metaloproteinasa 13 de la Matriz , Zinc , Hidroxiapatitas
7.
J Drugs Dermatol ; 22(5): 481-485, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37133481

RESUMEN

BACKGROUND: To investigate the effectiveness, safety, patient satisfaction, and cosmetic outcome of Methyl Aminolevulinate-Photodynamic Therapy (MAL-PDT) following curettage in order to make recommendations for its use in dermatology practices. METHODS: A retrospective chart review of patients who received MAL-PDT following curettage for the indication of basal cell carcinoma (BCC) between 2009 and 2016 at a single private clinic in Ontario, Canada. Two hundred and seventy-eight patients with 352 BCC lesions were included, consisting of 44.2% males (n=123) and 55.8% females (n=155) with a mean age of 57.24 years. The primary outcome measurement consisted of the cure rate. Secondary outcome measurements included side effects, patient satisfaction, and cosmetic outcome, as reported in the medical charts. RESULTS: The overall cure rate was 90.3% (n=318). After controlling for age, sex, and lesion type, nasal lesions were approximately 2.82 (95% CI: 1.24-6.40, P=0.01) times more likely to experience a recurrence. 18.3% of patients (n=51) reported side effects, the most common being burning (n=19). Of those who expressed satisfaction, 100% (n=25) reported being happy. Of lesions with cosmetic data, 90.3% displayed a good response (n=149). CONCLUSION: MAL-PDT following curettage is an effective and safe treatment option for BCC lesions with a good cosmetic outcome and suggested high patient satisfaction. J Drugs Dermatol. 2023;22(5): doi:10.36849/JDD.7133.


Asunto(s)
Carcinoma Basocelular , Fotoquimioterapia , Neoplasias Cutáneas , Masculino , Femenino , Humanos , Persona de Mediana Edad , Fármacos Fotosensibilizantes/efectos adversos , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/cirugía , Estudios Retrospectivos , Resultado del Tratamiento , Carcinoma Basocelular/tratamiento farmacológico , Carcinoma Basocelular/etiología , Fotoquimioterapia/efectos adversos , Ácido Aminolevulínico , Ontario , Legrado
8.
Phys Rev Lett ; 130(15): 150601, 2023 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-37115896

RESUMEN

Parametrized quantum circuits can be used as quantum neural networks and have the potential to outperform their classical counterparts when trained for addressing learning problems. To date, much of the results on their performance on practical problems are heuristic in nature. In particular, the convergence rate for the training of quantum neural networks is not fully understood. Here, we analyze the dynamics of gradient descent for the training error of a class of variational quantum machine learning models. We define wide quantum neural networks as parametrized quantum circuits in the limit of a large number of qubits and variational parameters. Then, we find a simple analytic formula that captures the average behavior of their loss function and discuss the consequences of our findings. For example, for random quantum circuits, we predict and characterize an exponential decay of the residual training error as a function of the parameters of the system. Finally, we validate our analytic results with numerical experiments.

9.
Trop Doct ; 53(2): 315-316, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36890727

RESUMEN

Linezolid-induced lactic acidosis is a rare, but life-threatening complication of a commonly used drug. Patients present with persistent lactic acidosis, hypoglycaemia, high central venous oxygen saturation and shock. Linezolid causes mitochondrial toxicity due to impaired oxidative phosphorylation. This is evidenced by cytoplasmic vacuolations in the myeloid and erythroid precursors of bone marrow smear as illustrated in our case. Discontinuation of the drug, administration of thiamine and haemodialysis reduces lactic acid levels.


Asunto(s)
Acidosis Láctica , Humanos , Linezolid/efectos adversos , Acidosis Láctica/inducido químicamente , Ácido Láctico
10.
Cureus ; 14(7): e27459, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36060343

RESUMEN

INTRODUCTION: A rapid surge in cases during the COVID-19 pandemic can overwhelm any healthcare system. It is imperative to triage patients who would require oxygen and ICU care, and predict mortality. Specific parameters at admission may help in identifying them. METHODOLOGY: A prospective observational study was undertaken in a COVID-19 ward of a tertiary care center. All baseline clinical and laboratory data were captured. Patients were followed till death or discharge. Univariable and multivariable logistic regression was used to find predictors of the need for oxygen, need for ICU care, and mortality. Objective scoring systems were developed for the same using the predictors. RESULTS: The study included 209 patients. Disease severity was mild, moderate, and severe in 98 (46.9%), 74 (35.4%), and 37 (17.7%) patients, respectively. The neutrophil-to-lymphocyte ratio (NLR) >4 was a common independent predictor of the need for oxygen (p<0.001), need for ICU transfer (p=0.04), and mortality (p=0.06). Clinical risk scores were developed (10*c-reactive protein (CRP) + 14.8*NLR + 12*urea), (10*aspartate transaminase (AST) + 15.7*NLR + 14.28*CRP), (10*NLR + 10.1*creatinine) which, if ≥14.8, ≥25.7, ≥10.1 predicted need for oxygenation, need for ICU transfer and mortality with a sensitivity and specificity (81.6%, 70%), (73.3%, 75.7%), (61.1%, 75%), respectively.  Conclusion: The NLR, CRP, urea, creatinine, and AST are independent predictors in identifying patients with poor outcomes. An objective scoring system can be used at the bedside for appropriate triaging of patients and utilization of resources.

11.
Cureus ; 14(7): e26688, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35959170

RESUMEN

Background and objective Patients suffering from thalassemia major are at higher risk of osteoporosis. Due to their decreased life expectancy, the number of adult patients is low. However, their bone health is rarely checked in developing countries like India. There is no data available in the literature on the bone mineral density (BMD) of adult (aged ≥18 years) thalassemia major patients in eastern India. In this study, we aimed to measure the BMD and serum calcium and vitamin D levels in adult thalassemia major patients and to compare them with healthy controls. Materials and methods We conducted this cross-sectional observational study at a tertiary care hospital in eastern India. We recruited adult thalassemia major patients who were not on calcium or vitamin D supplements. Their BMD was measured by dual-energy X-ray absorptiometry (DXA) on the lumbar spine (L1-L4). Venous blood was tested for serum calcium and vitamin D levels. We compared the parameters between the cases and controls by using the Mann-Whitney U test. Results A total of 31 (male = 19, female = 12) patients with a median age of 28 years comprised the case group. Age- and sex-matched controls showed similar height but higher weight and BMI. The serum calcium level was similar (p = 0.43) in the case and control groups but T-score (p = 0.0003) and vitamin D levels (p: <0.0001) were significantly lower in thalassemia major patients. Conclusion Based on our findings, adult thalassemia major patients have lower BMD and vitamin D levels. Although the serum calcium may be normal in these patients, they should still be screened both for BMD and vitamin D for prompt and early detection of risks and complications so that a proper management strategy can be implemented.

12.
Nat Commun ; 13(1): 4919, 2022 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-35995777

RESUMEN

Modern quantum machine learning (QML) methods involve variationally optimizing a parameterized quantum circuit on a training data set, and subsequently making predictions on a testing data set (i.e., generalizing). In this work, we provide a comprehensive study of generalization performance in QML after training on a limited number N of training data points. We show that the generalization error of a quantum machine learning model with T trainable gates scales at worst as [Formula: see text]. When only K ≪ T gates have undergone substantial change in the optimization process, we prove that the generalization error improves to [Formula: see text]. Our results imply that the compiling of unitaries into a polynomial number of native gates, a crucial application for the quantum computing industry that typically uses exponential-size training data, can be sped up significantly. We also show that classification of quantum states across a phase transition with a quantum convolutional neural network requires only a very small training data set. Other potential applications include learning quantum error correcting codes or quantum dynamical simulation. Our work injects new hope into the field of QML, as good generalization is guaranteed from few training data.

13.
Phys Rev Lett ; 128(18): 180505, 2022 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-35594093

RESUMEN

Several architectures have been proposed for quantum neural networks (QNNs), with the goal of efficiently performing machine learning tasks on quantum data. Rigorous scaling results are urgently needed for specific QNN constructions to understand which, if any, will be trainable at a large scale. Here, we analyze the gradient scaling (and hence the trainability) for a recently proposed architecture that we call dissipative QNNs (DQNNs), where the input qubits of each layer are discarded at the layer's output. We find that DQNNs can exhibit barren plateaus, i.e., gradients that vanish exponentially in the number of qubits. Moreover, we provide quantitative bounds on the scaling of the gradient for DQNNs under different conditions, such as different cost functions and circuit depths, and show that trainability is not always guaranteed. Our work represents the first rigorous analysis of the scalability of a perceptron-based QNN.


Asunto(s)
Algoritmos , Redes Neurales de la Computación , Aprendizaje Automático
14.
Elife ; 112022 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-35475970

RESUMEN

L,D-transpeptidase function predominates in atypical 3 → 3 transpeptide networking of peptidoglycan (PG) layer in Mycobacterium tuberculosis. Prior studies of L,D-transpeptidases have identified only the catalytic site that binds to peptide moiety of the PG substrate or ß-lactam antibiotics. This insight was leveraged to develop mechanism of its activity and inhibition by ß-lactams. Here, we report identification of an allosteric site at a distance of 21 Å from the catalytic site that binds the sugar moiety of PG substrates (hereafter referred to as the S-pocket). This site also binds a second ß-lactam molecule and influences binding at the catalytic site. We provide evidence that two ß-lactam molecules bind co-operatively to this enzyme, one non-covalently at the S-pocket and one covalently at the catalytic site. This dual ß-lactam-binding phenomenon is previously unknown and is an observation that may offer novel approaches for the structure-based design of new drugs against M. tuberculosis.


Asunto(s)
Mycobacterium tuberculosis , Peptidil Transferasas , Antibacterianos/farmacología , Dominio Catalítico , Mycobacterium tuberculosis/metabolismo , Peptidoglicano/metabolismo , Peptidil Transferasas/metabolismo , beta-Lactamas/metabolismo
15.
Phys Rev Lett ; 128(7): 070501, 2022 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-35244415

RESUMEN

The no-free-lunch (NFL) theorem is a celebrated result in learning theory that limits one's ability to learn a function with a training dataset. With the recent rise of quantum machine learning, it is natural to ask whether there is a quantum analog of the NFL theorem, which would restrict a quantum computer's ability to learn a unitary process with quantum training data. However, in the quantum setting, the training data can possess entanglement, a strong correlation with no classical analog. In this Letter, we show that entangled datasets lead to an apparent violation of the (classical) NFL theorem. This motivates a reformulation that accounts for the degree of entanglement in the training set. As our main result, we prove a quantum NFL theorem whereby the fundamental limit on the learnability of a unitary is reduced by entanglement. We employ Rigetti's quantum computer to test both the classical and quantum NFL theorems. Our Letter establishes that entanglement is a commodity in quantum machine learning.

16.
Inflamm Res ; 71(3): 277-292, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35175358

RESUMEN

INTRODUCTION: Ischemia-reperfusion injury (IRI) is the inexplicable aggravation of cellular dysfunction that results in blood flow restoration to previously ischemic tissues. COX mediates the oxidative conversion of AA to various prostaglandins and thromboxanes, which are involved in various physiological and pathological processes. In the pathophysiology of I/R injuries, COX has been found to play an important role. I/R injuries affect most vital organs and are characterized by inflammation, oxidative stress, cell death, and apoptosis, leading to morbidity and mortality. MATERIALS AND METHODS: A systematic literature review of Bentham, Scopus, PubMed, Medline, and EMBASE (Elsevier) databases was carried out to understand the Nature and mechanistic interventions of the Cyclooxygenase modulations in ischemic injury. Here, we have discussed the COX Physiology and downstream signalling pathways modulated by COX, e.g., Camp Pathway, Peroxisome Proliferator-Activated Receptor Activity, NF-kB Signalling, PI3K/Akt Signalling in ischemic injury. CONCLUSION: This review will discuss the various COX types, specifically COX-1 and COX-2, which are involved in developing I/R injury in organs such as the brain, spinal cord, heart, kidney, liver, and intestine.


Asunto(s)
Inhibidores de la Ciclooxigenasa , Daño por Reperfusión , Ciclooxigenasa 2/metabolismo , Inhibidores de la Ciclooxigenasa/farmacología , Humanos , Fosfatidilinositol 3-Quinasas , Prostaglandinas , Daño por Reperfusión/metabolismo
17.
Nature ; 603(7899): 145-151, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35045565

RESUMEN

COVID-19, which is caused by infection with SARS-CoV-2, is characterized by lung pathology and extrapulmonary complications1,2. Type I interferons (IFNs) have an essential role in the pathogenesis of COVID-19 (refs 3-5). Although rapid induction of type I IFNs limits virus propagation, a sustained increase in the levels of type I IFNs in the late phase of the infection is associated with aberrant inflammation and poor clinical outcome5-17. Here we show that the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, which controls immunity to cytosolic DNA, is a critical driver of aberrant type I IFN responses in COVID-19 (ref. 18). Profiling COVID-19 skin manifestations, we uncover a STING-dependent type I IFN signature that is primarily mediated by macrophages adjacent to areas of endothelial cell damage. Moreover, cGAS-STING activity was detected in lung samples from patients with COVID-19 with prominent tissue destruction, and was associated with type I IFN responses. A lung-on-chip model revealed that, in addition to macrophages, infection with SARS-CoV-2 activates cGAS-STING signalling in endothelial cells through mitochondrial DNA release, which leads to cell death and type I IFN production. In mice, pharmacological inhibition of STING reduces severe lung inflammation induced by SARS-CoV-2 and improves disease outcome. Collectively, our study establishes a mechanistic basis of pathological type I IFN responses in COVID-19 and reveals a principle for the development of host-directed therapeutics.


Asunto(s)
COVID-19/inmunología , COVID-19/patología , Interferón Tipo I/inmunología , Proteínas de la Membrana/metabolismo , Nucleotidiltransferasas/metabolismo , SARS-CoV-2/inmunología , Animales , COVID-19/metabolismo , COVID-19/virología , Células Cultivadas , ADN Mitocondrial/metabolismo , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Células Endoteliales/patología , Femenino , Regulación de la Expresión Génica/inmunología , Humanos , Inmunidad Innata , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/patología , Pulmón/virología , Macrófagos/inmunología , Proteínas de la Membrana/antagonistas & inhibidores , Ratones , Ratones Endogámicos C57BL , Neumonía/inmunología , Neumonía/metabolismo , Neumonía/patología , Neumonía/virología , SARS-CoV-2/patogenicidad , Transducción de Señal , Piel/inmunología , Piel/metabolismo , Piel/patología
18.
Nat Commun ; 12(1): 6961, 2021 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-34845216

RESUMEN

Variational Quantum Algorithms (VQAs) may be a path to quantum advantage on Noisy Intermediate-Scale Quantum (NISQ) computers. A natural question is whether noise on NISQ devices places fundamental limitations on VQA performance. We rigorously prove a serious limitation for noisy VQAs, in that the noise causes the training landscape to have a barren plateau (i.e., vanishing gradient). Specifically, for the local Pauli noise considered, we prove that the gradient vanishes exponentially in the number of qubits n if the depth of the ansatz grows linearly with n. These noise-induced barren plateaus (NIBPs) are conceptually different from noise-free barren plateaus, which are linked to random parameter initialization. Our result is formulated for a generic ansatz that includes as special cases the Quantum Alternating Operator Ansatz and the Unitary Coupled Cluster Ansatz, among others. For the former, our numerical heuristics demonstrate the NIBP phenomenon for a realistic hardware noise model.

19.
Indian J Med Res ; 153(5&6): 665-670, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-34414924

RESUMEN

Background & objectives: In the present scenario, the most common sample for diagnosis of COVID-19 by reverse transcription polymerase chain reaction (RT-PCR) is nasal and throat swab (NTS). Other sampling options such as gargle lavage have found limited application in clinical use mostly because of unavailability of an appropriate gargling liquid. This study was conducted to assess the stability of SARS-CoV-2 RNA in normal saline at 4°C that can serve as a gargling liquid as well as a transport medium. The study also looked at the agreement between NTS and gargle lavage/saliva for the detection of SARS-CoV-2. Methods: In 29 consecutive real-time RT-PCR (rRT-PCR) positive COVID-19 patients, paired NTS, gargle and saliva samples were taken. Samples were processed by rRT-PCR for the detection of SARS-CoV-2 RNA. To assess the SARS-CoV-2 RNA stability in normal saline, gargle lavage specimens were divided into two aliquots; one subset of the specimen was run within 4-6 h along with the routine samples (NTS and saliva) and the other subset was stored at 4°C and processed after 24-30 h. Agreement between cycle threshold (Ct) values from both the runs was compared using Bland-Altman (BA) analysis. Results: The positivity rates of rRT-PCR in NTS, saliva and gargle lavage samples were 82.7 (24/29), 79.3 (23/29) and 86.2 per cent (25/29), respectively. BA plot showed a good agreement between the Ct values of fresh and stored gargle samples, stipulating that there were no significant differences in the approximate viral load levels between the fresh and stored gargle lavage samples (bias: E gene -0.64, N gene -0.51, ORF gene -0.19). Interpretation & conclusions: Our study results show stability of SARS-CoV-2 RNA in the gargle samples collected using normal saline up to 24-30 h. Gargle lavage and saliva specimen collection are cost-effective and acceptable methods of sampling for the detection of SARS-CoV-2 RNA by rRT-PCR. These simplified, inexpensive and acceptable methods of specimen collection would reduce the cost and workload on healthcare workers for sample collection.


Asunto(s)
COVID-19 , Saliva , Humanos , Nasofaringe , Faringe , ARN Viral/genética , SARS-CoV-2 , Manejo de Especímenes , Irrigación Terapéutica
20.
Elife ; 102021 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-34219648

RESUMEN

Uropathogenic Escherichia coli (UPEC) proliferate within superficial bladder umbrella cells to form intracellular bacterial communities (IBCs) during early stages of urinary tract infections. However, the dynamic responses of IBCs to host stresses and antibiotic therapy are difficult to assess in situ. We develop a human bladder-chip model wherein umbrella cells and bladder microvascular endothelial cells are co-cultured under flow in urine and nutritive media respectively, and bladder filling and voiding mimicked mechanically by application and release of linear strain. Using time-lapse microscopy, we show that rapid recruitment of neutrophils from the vascular channel to sites of infection leads to swarm and neutrophil extracellular trap formation but does not prevent IBC formation. Subsequently, we tracked bacterial growth dynamics in individual IBCs through two cycles of antibiotic administration interspersed with recovery periods which revealed that the elimination of bacteria within IBCs by the antibiotic was delayed, and in some instances, did not occur at all. During the recovery period, rapid proliferation in a significant fraction of IBCs reseeded new foci of infection through bacterial shedding and host cell exfoliation. These insights reinforce a dynamic role for IBCs as harbors of bacterial persistence, with significant consequences for non-compliance with antibiotic regimens.


Urinary tract infections are one of the most common reasons people need antibiotics. These bacterial infections are typically caused by uropathogenic Escherichia coli (also known as UPEC), which either float freely in the urine and wash away when the bladder empties, or form communities inside cells that the bladder struggles to clear. It is possible that the bacteria living within cells are also more protected from the immune system and antibiotics. But this is hard to study in animal models. To overcome this, Sharma et al. built a 'bladder-chip' which mimics the interface between the blood vessels and the tissue layers of the human bladder. Similar chip devices have also been made for other organs. However, until now, no such model had been developed for the bladder. On the chip created by Sharma et al. is a layer of bladder cells which sit at the bottom of a channel filled with diluted human urine. These cells were infected with UPEC, and then imaged over time to see how the bacteria moved, interacted with the bladder cells, and aggregated together. Immune cells from human blood were then added to a vascular channel underneath the bladder tissue, which is coated with endothelial cells that normally line blood vessels. The immune cells rapidly crossed the endothelial barrier and entered the bladder tissue, and swarmed around sites of infection. In some instances, they released the contents of their cells to form net-like traps to catch the bacteria. But these traps failed to remove the bacteria living inside bladder cells. Antibiotics were then added to the urine flowing over the bladder cells as well as the vascular channel, similar to how drugs would be delivered in live human tissue. Sharma et al. discovered that the antibiotics killed bacteria residing in bladder cells slower than bacteria floating freely in the urine. Furthermore, they found that bacteria living in tightly packed communities within bladder cells were more likely to survive treatment and go on to re-infect other parts of the tissue. Antibiotic resistance is a pressing global challenge, and recurrent urinary tract infections are a significant contributor. The bladder-chip presented here could further our understanding of how these bacterial infections develop in vivo and how good antibiotics are at removing them. This could help researchers identify the best dosing and treatment strategies, as well as provide a platform for rapidly testing new antibiotic drugs and other therapies.


Asunto(s)
Técnicas Bacteriológicas/instrumentación , Dispositivos Laboratorio en un Chip , Vejiga Urinaria/irrigación sanguínea , Infecciones Urinarias/microbiología , Escherichia coli Uropatógena , Línea Celular Tumoral , Técnicas de Cocultivo , Células Endoteliales/fisiología , Humanos , Neutrófilos/fisiología
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