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1.
Langmuir ; 40(12): 6471-6483, 2024 03 26.
Artículo en Inglés | MEDLINE | ID: mdl-38466805

RESUMEN

Nanocarriers have attracted considerable interest due to their prospective applications in the delivery of anticancer medications and their distinct bioactivities. Biogenic nanostructures can be effective nanocarriers for delivering drugs as a consequence of sustainable and biodegradable biomass-derived nanostructures that perform specific functions. In this case, a vanadium oxide (V2O5) and mesoporous carbon@V2O5 (C@V) composite was developed as a possible drug delivery system, and its bioactivities, including antioxidant, antibacterial, and anticancer, were investigated. Doxorubicin (DOX), an anticancer drug, was introduced to the nanoparticles, and the loading and release investigation was conducted. Strong interfacial interactions between mesoporous carbon (MC) and V2O5 nanostructures have been found to improve performance in drug loading and release studies and bioactivities. After incubation, the potent anticancer effectiveness was seen based on C@V nanocomposite. This sample was also utilized to research potential biomedical uses as an antioxidant, antibacterial, and anticancer. The most effective antioxidant, the C@V sample (61.2%), exhibited a higher antioxidant activity than the V-2 sample (44.61%). The C@V sample ultimately attained a high DOX loading efficacy of 88%, in comparison to a pure V2O5 sample (V-2) loading efficacy of 80%. Due to the combination of mesoporous carbon and V2O5, which increases specific surface area and surface sites of action as well as the morphology, it proved that the mesoporous carbon@V2O5 composite (C@V) sample demonstrated greater efficacy.


Asunto(s)
Antineoplásicos , Nanoestructuras , Carbono/química , Antioxidantes/farmacología , Antineoplásicos/farmacología , Antineoplásicos/química , Doxorrubicina/química , Nanoestructuras/química , Antibacterianos/farmacología , Antibacterianos/uso terapéutico
2.
Pract Neurol ; 24(5): 422-427, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-38960597

RESUMEN

We report unusual cases of combined central and peripheral demyelination in two siblings related to pregnancy, each presenting with progressive tetraparesis and cranial nerve palsies. The elder sister had a relapsing-remitting course with optic nerve dysfunction and died during a relapse from respiratory insufficiency. The younger sister presented with disorientation and acute-onset limb and facial weakness. She responded well to corticosteroid therapy. Their clinical presentation, response to immunomodulatory therapy, nerve conduction studies, cerebrospinal fluid and histology supported an acquired demyelinating cause. Whole-exome sequencing identified variants in two genes not previously linked to this clinical phenotype. Serological tests for antibody-mediated demyelination were negative. Despite the undefined pathogenesis, these cases provide a platform to explore the confluence of genetic, immune and environmental factors in the context of acquired demyelination. We discuss the differential diagnosis and a diagnostic approach to such cases from the perspectives of neuroimmunology and neurogenetics.


Asunto(s)
Enfermedades Desmielinizantes , Hermanos , Humanos , Femenino , Enfermedades Desmielinizantes/genética , Enfermedades Desmielinizantes/diagnóstico , Adulto
3.
Annu Rev Genomics Hum Genet ; 21: 117-138, 2020 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-32283947

RESUMEN

When the Human Genome Project was completed in 2003, automated Sanger DNA sequencing with fluorescent dye labels was the dominant technology. Several nascent alternative methods based on older ideas that had not been fully developed were the focus of technical researchers and companies. Funding agencies recognized the dynamic nature of technology development and that, beyond the Human Genome Project, there were growing opportunities to deploy DNA sequencing in biological research. Consequently, the National Human Genome Research Institute of the National Institutes of Health created a program-widely known as the Advanced Sequencing Technology Program-that stimulated all stages of development of new DNA sequencing methods, from innovation to advanced manufacturing and production testing, with the goal of reducing the cost of sequencing a human genome first to $100,000 and then to $1,000. The events of this period provide a powerful example of how judicious funding of academic and commercial partners can rapidly advance core technology developments that lead to profound advances across the scientific landscape.


Asunto(s)
Genoma Humano , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Proyecto Genoma Humano , Análisis de Secuencia de ADN/métodos , Humanos
4.
PLoS Pathog ; 17(9): e1009871, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34555123

RESUMEN

HIV cerebrospinal fluid (CSF) escape, where HIV is suppressed in blood but detectable in CSF, occurs when HIV persists in the CNS despite antiretroviral therapy (ART). To determine the virus producing cell type and whether lowered CSF ART levels are responsible for CSF escape, we collected blood and CSF from 156 neurosymptomatic participants from Durban, South Africa. We observed that 28% of participants with an undetectable HIV blood viral load showed CSF escape. We detected host cell surface markers on the HIV envelope to determine the cellular source of HIV in participants on the first line regimen of efavirenz, emtricitabine, and tenofovir. We confirmed CD26 as a marker which could differentiate between T cells and macrophages and microglia, and quantified CD26 levels on the virion surface, comparing the result to virus from in vitro infected T cells or macrophages. The measured CD26 level was consistent with the presence of T cell produced virus. We found no significant differences in ART concentrations between CSF escape and fully suppressed individuals in CSF or blood, and did not observe a clear association with drug resistance mutations in CSF virus which would allow HIV to replicate. Hence, CSF HIV in the face of ART may at least partly originate in CD4+ T cell populations.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/líquido cefalorraquídeo , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Linfocitos T/virología , Adulto , Alquinos/uso terapéutico , Benzoxazinas/uso terapéutico , Ciclopropanos/uso terapéutico , Emtricitabina/uso terapéutico , Femenino , VIH-1 , Humanos , Masculino , Persona de Mediana Edad , Tenofovir/uso terapéutico
5.
Langmuir ; 39(33): 11910-11924, 2023 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-37552874

RESUMEN

Scientists have investigated the possibility of employing nanomaterials as drug carriers. These nanomaterials can preserve their content and transport it to the target region in the body. In this investigation, we proposed a simple method for developing distinctive, bioderived nanostructures with mesoporous carbon nanoparticles impregnated with tungsten oxide (WO3). Prior to characterizing and encapsulating WO3 with bioderived mesoporous carbon, the anticancer drug doxorubicin (DOX) was added to the nanoparticles and examined loading and release study. The approaches for both nanoparticle production and characterization are discussed in detail. Colloidal qualities of the nanomaterial can be effectively preserved while also allowing transdermal transportation of nanoparticles into the body by forming them into green, reusable, and porous nanostructures. Although the theories of nanoparticles and bioderived carbon each have been studied separately, the combination presents a new route to applications connected to nanomedicine. Furthermore, this sample was used to study exotic biomedical applications, such as antioxidant, antimicrobial, and anticancer activities. The W-3 sample had lower antioxidant activity (44.01%) than the C@W sample (56.34%), which was the most potent. A high DOX entrapment effectiveness of 97% was eventually achieved by the C@W sample, compared to a pure WO3 entrapment efficiency of 91%. It was observed that the Carbon/WO3 composite (C@W) sample showed more efficacy because the mesoporous carbon composition with WO3 increases the average surface area and surface-active locations.


Asunto(s)
Nanocompuestos , Nanopartículas , Neoplasias , Humanos , Portadores de Fármacos/química , Carbono/química , Doxorrubicina/química , Nanopartículas/química , Neoplasias/tratamiento farmacológico , Porosidad
6.
Chem Biodivers ; 20(8): e202300332, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37461844

RESUMEN

The present study shows the chemical profile, antimicrobial, antiproliferative, and apoptotic effects of Stemodia viscosa extracts. Thirteen bioactive compounds were identified in the 80 % ethanolic extract by GC/MS analysis. The acetone extract exhibited a higher content of flavonoids and phenols of 805.10 µg QE/mg DW and 89.31 µg GAE/mg DW extracts, respectively. Furthermore, the acetone extract possessed the highest antioxidant activity (IC50 =9.96 µg/mL). The 80 % ethanolic extract exhibited significant antimicrobial activity; the highest activity was observed against Staphylococcus aureus with a zone of inhibition of 25±0.51 mm, MIC value of 4 mg/mL, and MBC value of 8 mg/mL. The antiproliferative results revealed the presence of anticancer activity with an IC50 =91.562 and 74.362 µg/mL against the B16F10 skin and COLO205 colon cancer cells, respectively. The flow cytometric analysis shows that the plant extracts cause cancer cell death through the induction of apoptosis. Our findings confirmed that Stemodia viscosa is a potential source of biologically active compounds.


Asunto(s)
Acetona , Antiinfecciosos , Acetona/análisis , Antiinfecciosos/química , Extractos Vegetales/química , Fitoquímicos/farmacología , Fitoquímicos/química , Cromatografía de Gases y Espectrometría de Masas , Antioxidantes/química , Flavonoides/farmacología
7.
Biochem Biophys Res Commun ; 637: 267-275, 2022 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-36410276

RESUMEN

Phosphoinositide 3-kinase (PI3K) pathway mediates key signaling events downstream to B-cell receptor (BCR) for survival of mature B-cells, and overexpression or overactivation of PI3Kδ is crucial for B-cell malignancies such as diffuse large B-cell lymphoma (DLBCL). Small molecule PI3Kδγ inhibitors, with a known potential to reduce activated B-cell (ABC)-DLBCL transformation, form an important class of therapeutics approved for follicular lymphoma (FL), chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL). In this study, we describe discovery of a potent, selective and efficacious dual PI3Kδγ inhibitor, LL-00084282, having a differentiated efficacy profile in human ABC- and germinal center B-cell (GCB)-DLBCL cell lines. LL-00084282 displayed high potency and superior PI3Kδγ engagement with excellent selectivity over other PI3K isoforms at both IC50/90 concentrations in biochemical and cell-based assays. In contrast to selective PI3Kδ inhibitors, LL-00084282 showed superior and potent anticancer activity in both ABC- and GCB-DLBCL cell lines. LL-00084282 demonstrated in-vivo efficacy in OCI-Ly10 and SU-DHL-6 xenografts with good tolerability. Furthermore, LL-00084282 inhibited pro-inflammatory cytokine secretion and reduced basophil activation in human PBMCs, showing potential implications in immunoinflammatory conditions. Good pharmacokinetic properties in higher species and desirable efficacy profile highlights potential of this novel PI3Kδγ inhibitor for further clinical evaluation in DLBCL patients.


Asunto(s)
Leucemia Linfocítica Crónica de Células B , Linfoma de Células B Grandes Difuso , Inhibidores de las Quinasa Fosfoinosítidos-3 , Humanos , Linfocitos B , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Fosfatidilinositol 3-Quinasas , Inhibidores de las Quinasa Fosfoinosítidos-3/farmacología , Línea Celular Tumoral
8.
Respiration ; 99(2): 125-131, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31935716

RESUMEN

BACKGROUND: Joint pain is frequently observed in patients on antituberculous treatment, and pyrazinamide is known to be associated with joint pain in patients receiving antituberculous treatment. Fluoroquinolone-associated joint pain and tendon injury have been reported in long-term corticosteroid and transplant recipients, but data are lacking in patients with tuberculosis. OBJECTIVES: The objective of this study was to examine the incidence of joint pain manifested during administration of antituberculous therapy and their association with fluoroquinolones. METHODS: Patients diagnosed with tuberculosis attending the outpatient clinic over a period of 1 year were reviewed and divided into 3 groups: group A receiving pyrazinamide, group B receiving a fluoroquinolone, and group C receiving both pyrazinamide and a fluoroquinolone. Latency to onset of joint pain was noted in all 3 groups. Joint pain was initially managed with analgesics, and associated hyperuricemia was treated with allopurinol/febuxostat. Causative drugs were stopped in case of intolerable joint pain. RESULTS: 260 patients (47% females, aged 38 ± 18 years; mean ± SD) were included [group A (n = 140), group B (n = 81), and group C (n = 39)]. Overall, 76/260 (29%) patients developed joint pain: group A - 24/140 patients (17%), group B - 32/81 patients (40%), and group C - 20/39 patients (51%). The median latency to the onset of joint pain was 83 days (interquartile range, IQR 40-167): 55 days (IQR 32-66) in group A, 138 days (IQR 74-278) in group B, and 88 days (IQR 34-183) in group C. Hyperuricemia was present in 12/24 (50%) patients in group A and 11/20 (55%) patients in group C. Pyrazinamide was stopped in 7/140 (5%) patients in group A, fluoroquinolones in 6/81 (7%) patients in group B, and both pyrazinamide and fluoroquinolones were stopped in 5/39 (13%) patients in group C because of intolerable joint pain. Major joints affected were knees and ankles. CONCLUSION: There is a high incidence of joint pain in patients receiving antituberculous treatment, which is higher when fluoroquinolones or the pyrazinamide-fluoroquinolone combination are administered as compared to pyrazinamide alone.


Asunto(s)
Antituberculosos/uso terapéutico , Artralgia/epidemiología , Fluoroquinolonas/uso terapéutico , Pirazinamida/uso terapéutico , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Pulmonar/tratamiento farmacológico , Acetaminofén/uso terapéutico , Adulto , Alopurinol/uso terapéutico , Analgésicos no Narcóticos/uso terapéutico , Artralgia/sangre , Artralgia/tratamiento farmacológico , Estudios de Casos y Controles , Febuxostat/uso terapéutico , Femenino , Supresores de la Gota/uso terapéutico , Humanos , Hiperuricemia/sangre , Hiperuricemia/tratamiento farmacológico , Incidencia , India/epidemiología , Levofloxacino/uso terapéutico , Masculino , Persona de Mediana Edad , Moxifloxacino/uso terapéutico , Adulto Joven
9.
Dig Dis Sci ; 61(3): 890-9, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26346997

RESUMEN

BACKGROUND: Prior to withdrawing the EUS-FNA needle from the lesion, the stopcock of the suction syringe is closed to reduce contamination. Residual negative pressure (RNP) may persist in the needle despite closing the stopcock. AIMS: To determine whether neutralizing RNP before withdrawing the needle will improve the cytology yield. METHODS: Bench-top testing was done to confirm the presence of RNP followed by a prospective, randomized, cross-over study on patients with pancreas mass. Ten milliliters of suction was applied to the FNA needle. Before withdrawing the needle from the lesion, the stopcock was closed. Based on randomization, the first pass was done with the stopcock either attached to the needle (S+) or disconnected (S-) to allow air to enter and neutralize RNP and accordingly the second pass was crossed over to S+ or S-. On-site cytopathologist was blinded to S+/S-. RESULTS: Bench tests confirmed the presence of RNP which was successfully neutralized by disconnecting the syringe (S-) from the needle. Sixty patients were enrolled, 120 samples analyzed. S+ samples showed significantly greater GI tract contamination compared to S- samples (16.7 vs. 6.7%, p = 0.03). Of the 53 patients confirmed to have pancreas adenocarcinoma, FNA using S- approach was positive in 49 (93%) compared to 40 using the S+ approach (76%, p = 0.02). CONCLUSIONS: Despite closing the stopcock of the suction syringe, RNP is present in the FNA needle. Neutralizing RNP prior to withdrawing the needle from the target lesion significantly decreased GI tract contamination of the sample thereby improving the FNA cytology yield. CLINICAL TRIALS REGISTRATION NUMBER: NCT01995474.


Asunto(s)
Adenocarcinoma/patología , Biopsia por Aspiración con Aguja Fina Guiada por Ultrasonido Endoscópico/métodos , Tumores Neuroendocrinos/patología , Neoplasias Pancreáticas/patología , Succión/métodos , Jeringas , Adenocarcinoma/diagnóstico , Anciano , Estudios Cruzados , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tumores Neuroendocrinos/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/secundario , Presión
10.
Sensors (Basel) ; 16(3)2016 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-26959021

RESUMEN

Single-unit recording neural probes have significant advantages towards improving signal-to-noise ratio and specificity for signal acquisition in brain-to-computer interface devices. Long-term effectiveness is unfortunately limited by the chronic injury response, which has been linked to the mechanical mismatch between rigid probes and compliant brain tissue. Small, flexible microelectrodes may overcome this limitation, but insertion of these probes without buckling requires supporting elements such as a stiff coating with a biodegradable polymer. For these coated probes, there is a design trade-off between the potential for successful insertion into brain tissue and the degree of trauma generated by the insertion. The objective of this study was to develop and validate a finite element model (FEM) to simulate insertion of coated neural probes of varying dimensions and material properties into brain tissue. Simulations were performed to predict the buckling and insertion forces during insertion of coated probes into a tissue phantom with material properties of brain. The simulations were validated with parallel experimental studies where probes were inserted into agarose tissue phantom, ex vivo chick embryonic brain tissue, and ex vivo rat brain tissue. Experiments were performed with uncoated copper wire and both uncoated and coated SU-8 photoresist and Parylene C probes. Model predictions were found to strongly agree with experimental results (<10% error). The ratio of the predicted buckling force-to-predicted insertion force, where a value greater than one would ideally be expected to result in successful insertion, was plotted against the actual success rate from experiments. A sigmoidal relationship was observed, with a ratio of 1.35 corresponding to equal probability of insertion and failure, and a ratio of 3.5 corresponding to a 100% success rate. This ratio was dubbed the "safety factor", as it indicated the degree to which the coating should be over-designed to ensure successful insertion. Probability color maps were generated to visually compare the influence of design parameters. Statistical metrics derived from the color maps and multi-variable regression analysis confirmed that coating thickness and probe length were the most important features in influencing insertion potential. The model also revealed the effects of manufacturing flaws on insertion potential.


Asunto(s)
Técnicas Biosensibles/métodos , Interfaces Cerebro-Computador , Red Nerviosa , Polímeros/química , Animales , Fenómenos Biomecánicos , Electrodos , Análisis de Elementos Finitos , Humanos , Ratas , Xilenos/química
11.
J Infect Dis ; 212(11): 1827-34, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26014799

RESUMEN

Improved biomarkers are needed for tuberculosis. To develop tests based on products secreted by tubercle bacilli that are strictly associated with viability, we evaluated 3 bacterial-derived, species-specific, small molecules as biomarkers: 2 mycobactin siderophores and tuberculosinyladenosine. Using liquid chromatography-tandem mass spectrometry, we demonstrated the presence of 1 or both mycobactins and/or tuberculosinyladenosine in serum and whole lung tissues from infected mice and sputum, cerebrospinal fluid (CSF), or lymph nodes from infected patients but not uninfected controls. Detection of the target molecules distinguished host infection status in 100% of mice with both serum and lung as the target sample. In human subjects, we evaluated detection of the bacterial small molecules (BSMs) in multiple body compartments in 3 patient cohorts corresponding to different forms of tuberculosis. We detected at least 1 of the 3 molecules in 90%, 71%, and 40% of tuberculosis patients' sputum, CSF, and lymph node samples, respectively. In paucibacillary forms of human tuberculosis, which are difficult to diagnose even with culture, detection of 1 or more BSM was rapid and compared favorably to polymerase chain reaction-based detection. Secreted BSMs, detectable in serum, warrant further investigation as a means for diagnosis and therapeutic monitoring in patients with tuberculosis.


Asunto(s)
Biomarcadores/análisis , Mycobacterium tuberculosis/química , Oxazoles/análisis , Tuberculosis/diagnóstico , Adenosina/análogos & derivados , Adenosina/análisis , Animales , Técnicas de Tipificación Bacteriana , Cromatografía Liquida , Humanos , Pulmón/microbiología , Ratones , Mycobacterium tuberculosis/aislamiento & purificación , Esputo/microbiología , Espectrometría de Masas en Tándem
12.
J Virol ; 88(17): 9579-89, 2014 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-24920805

RESUMEN

UNLABELLED: It remains a challenge to develop a successful human immunodeficiency virus (HIV) vaccine that is capable of preventing infection. Here, we utilized the benefits of CD40L, a costimulatory molecule that can stimulate both dendritic cells (DCs) and B cells, as an adjuvant for our simian immunodeficiency virus (SIV) DNA vaccine in rhesus macaques. We coexpressed the CD40L with our DNA/SIV vaccine such that the CD40L is anchored on the membrane of SIV virus-like particle (VLP). These CD40L containing SIV VLPs showed enhanced activation of DCs in vitro. We then tested the potential of DNA/SIV-CD40L vaccine to adjuvant the DNA prime of a DNA/modified vaccinia virus Ankara (MVA) vaccine in rhesus macaques. Our results demonstrated that the CD40L adjuvant enhanced the functional quality of anti-Env antibody response and breadth of anti-SIV CD8 and CD4 T cell responses, significantly delayed the acquisition of heterologous mucosal SIV infection, and improved viral control. Notably, the CD40L adjuvant enhanced the control of viral replication in the gut at the site of challenge that was associated with lower mucosal CD8 immune activation, one of the strong predictors of disease progression. Collectively, our results highlight the benefits of CD40L adjuvant for enhancing antiviral humoral and cellular immunity, leading to enhanced protection against a pathogenic SIV. A single adjuvant that enhances both humoral and cellular immunity is rare and thus underlines the importance and practicality of CD40L as an adjuvant for vaccines against infectious diseases, including HIV-1. IMPORTANCE: Despite many advances in the field of AIDS research, an effective AIDS vaccine that can prevent infection remains elusive. CD40L is a key stimulator of dendritic cells and B cells and can therefore enhance T cell and antibody responses, but its overly potent nature can lead to adverse effects unless used in small doses. In order to modulate local expression of CD40L at relatively lower levels, we expressed CD40L in a membrane-bound form, along with SIV antigens, in a nucleic acid (DNA) vector. We tested the immunogenicity and efficacy of the CD40L-adjuvanted vaccine in macaques using a heterologous mucosal SIV infection. The CD40L-adjuvanted vaccine enhanced the functional quality of anti-Env antibody response and breadth of anti-SIV T cell responses and improved protection. These results demonstrate that VLP-membrane-bound CD40L serves as a novel adjuvant for an HIV vaccine.


Asunto(s)
Anticuerpos Antivirales/sangre , Ligando de CD40/administración & dosificación , Inmunidad Celular , Vacunas contra el SIDAS/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/prevención & control , Vacunación/métodos , Vacunas de ADN/inmunología , Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/genética , Animales , Linfocitos T CD4-Positivos/inmunología , Ligando de CD40/genética , Linfocitos T CD8-positivos/inmunología , Portadores de Fármacos/administración & dosificación , Inmunidad Mucosa , Macaca mulatta , Vacunas contra el SIDAS/administración & dosificación , Vacunas contra el SIDAS/genética , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/genética , Virus de la Inmunodeficiencia de los Simios/inmunología , Vacunas de ADN/administración & dosificación , Vacunas de ADN/genética , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología , Vacunas de Partículas Similares a Virus/administración & dosificación , Vacunas de Partículas Similares a Virus/genética , Vacunas de Partículas Similares a Virus/inmunología , Virus Vaccinia/genética
13.
Biomed Microdevices ; 17(2): 34, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25681971

RESUMEN

We report a fabrication process for coating neural probes with an ultrafast degrading polymer to create consistent and reproducible devices for neural tissue insertion. The rigid polymer coating acts as a probe insertion aid, but resorbs within hours post-implantation. Despite the feasibility for short term neural recordings from currently available neural prosthetic devices, most of these devices suffer from long term gliosis, which isolates the probes from adjacent neurons, increasing the recording impedance and stimulation threshold. The size and stiffness of implanted probes have been identified as critical factors that lead to this long term gliosis. Smaller, more flexible probes that match the mechanical properties of brain tissue could allow better long term integration by limiting the mechanical disruption of the surrounding tissue during and after probe insertion, while being flexible enough to deform with the tissue during brain movement. However, these small flexible probes inherently lack the mechanical strength to penetrate the brain on their own. In this work, we have developed a micromolding method for coating a non-functional miniaturized SU-8 probe with an ultrafast degrading tyrosine-derived polycarbonate (E5005(2K)). Coated, non-functionalized probes of varying dimensions were reproducibly fabricated with high yields. The polymer erosion/degradation profiles of the probes were characterized in vitro. The probes were also mechanically characterized in ex vivo brain tissue models by measuring buckling and insertion forces during probe insertion. The results demonstrate the ability to produce polymer coated probes of consistent quality for future in vivo use, for example to study the effects of different design parameters that may affect tissue response during long term chronic intra-cortical microelectrode neural recordings.


Asunto(s)
Materiales Biocompatibles/química , Ensayo de Materiales/métodos , Polímeros/química , Prótesis e Implantes , Animales , Materiales Biocompatibles/metabolismo , Encéfalo/embriología , Interfaces Cerebro-Computador , Embrión de Pollo , Compuestos Epoxi/química , Microtecnología , Cemento de Policarboxilato/química , Polímeros/metabolismo , Ratas Sprague-Dawley , Sefarosa/química , Temperatura , Tirosina/química
14.
J Clin Microbiol ; 52(10): 3777-80, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25056328

RESUMEN

There are no data about the comparative accuracy of commercially available nucleic acid amplification tests (GeneXpert MTB/RIF and Roche Amplicor) for the diagnosis of tuberculous meningitis (TBM). A total of 148 patients with suspected TBM were evaluated, and cultures served as the reference standard. The sensitivities and specificities (95% confidence interval [CI]) for the Amplicor and Xpert MTB/RIF tests were similar: 46 (31-60) versus 50 (33-67) and 99 (93-100) and 94 (84-99), respectively.


Asunto(s)
Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Tuberculosis Meníngea/diagnóstico , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad
15.
Heliyon ; 10(7): e28023, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38576556

RESUMEN

Vacuum impregnation (VI) is a novel, non-thermal treatment that aims to modify the composition of food material by partially removing water and air and impregnating it with physiologically active compounds without affecting the structural integrity of food matrix. Application of VI accelerates the mass transfer processes, which leads to few changes in food composition and improves dehydration. Large volumes in intracellular spaces of fruit and vegetable tissues make it suitable to introduce different agents like nutrients, cryoprotectants, browning inhibitors, enzymes, and chemicals; enhancing texture profile and inhibiting tissue softening, or compounds lowering water activity and pH. water activity Thus, the VI may help to achieve new product quality associated with physicochemical features and sensory attributes. This review highlights the evolution and mechanism of VI technique, major factors affecting VI of fruits and vegetables and their responses to processing, and industrial relevance. Vacuum impregnation consists ability to revolutionize various aspects of food processing and preservation. VI serves as a versatile tool that enhances the quality, shelf life, and nutritional content of processed fruits and vegetables. It offers unique advantages of altering product composition by introducing desired compounds while preserving structural integrity. VI improves mass transfer processes, reduces water content, enhances the absorption of nutrients, antioxidants, and preservatives. This technology finds application in producing fortified foods, extending shelf life, and creating innovative products with improved sensory attributes. VI's ability to efficiently impregnate substances into porous materials, combined with its energy-saving potential and compatibility with other processing methods, makes it a valuable tool in the food industry. As consumers demand healthier and long-lasting products, VI emerges as a promising solution for meeting market demands.

16.
Biomicrofluidics ; 18(4): 044108, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39184284

RESUMEN

The study unveils a simple, non-invasive method to perform micromixing with the help of spatiotemporal variation in the Lorentz force inside a microchannel decorated with chemically heterogeneous walls. Computational fluid dynamics simulations have been utilized to investigate micromixing under the coupled influence of electric and magnetic fields, namely, electromagnetohydrodynamics, to alter the direction of the Lorentz force at the specific locations by creating the reverse flow zones where the pressure gradient, ∇ p = 0 . The study explores the impact of periodicity, distribution, and size of electrodes alongside the magnitude of applied field intensity, the flow rate of the fluid, and the nature of the electric field on the generation of the mixing vortices and their strength inside the microchannels. The results illustrate that the wall heterogeneities can indeed enforce the formation of localized on-demand vortices when the strength of the localized reverse flow overcomes the inertia of the mainstream flow. In such a scenario, while the vortex size and strength are found to increase with the size of the heterogeneous electrodes and field intensities, the number of vortices increases with the number of heterogeneous electrodes decorated on the channel wall. The presence of a non-zero pressure-driven inflow velocity is found to subdue the strength of the vortices to restrict the mixing facilitated by the localized variation of the Lorentz force. Interestingly, the usage of an alternating current (AC) electric field is found to provide an additional non-invasive control on the mixing vortices by enabling periodic changes in their direction of rotation. A case study in this regard discloses the possibility of rapid mixing with the usage of an AC electric field for a pair of miscible fluids inside a microchannel.

17.
Vaccines (Basel) ; 12(7)2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39066417

RESUMEN

Tuberculosis (TB) remains a global health threat, necessitating innovative strategies for control and prevention. This comprehensive review explores the Mycobacterium tuberculosis Lysine Exporter (LysE) gene, unveiling its multifaceted roles and potential uses in controlling and preventing tuberculosis (TB). As a pivotal player in eliminating excess L-lysine and L-arginine, LysE contributes to the survival and virulence of M. tuberculosis. This review synthesizes findings from different electronic databases and includes 13 studies focused on the LysE of M. tuberculosis. The research unveils that LysE can be a potential drug target, a diagnostic marker for TB, and a promising candidate for vaccine development. The absence of LysE in the widely used BCG vaccine underscores its uniqueness and positions it as a novel area for TB prevention. In conclusion, this review underscores the significance of LysE in TB pathogenesis and its potential as a drug target, diagnostic marker, and vaccine candidate. The multifaceted nature of LysE positions it at the forefront of innovative approaches to combat TB, calling for sustained research efforts to harness its full potential in the global fight against this infectious disease.

18.
PLoS Med ; 10(10): e1001536, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24167451

RESUMEN

BACKGROUND: Tuberculous meningitis (TBM) is difficult to diagnose promptly. The utility of the Xpert MTB/RIF test for the diagnosis of TBM remains unclear, and the effect of host- and sample-related factors on test performance is unknown. This study sought to evaluate the sensitivity and specificity of Xpert MTB/RIF for the diagnosis of TBM. METHODS AND FINDINGS: 235 South-African patients with a meningeal-like illness were categorised as having definite (culture or Amplicor PCR positive), probable (anti-TBM treatment initiated but microbiological confirmation lacking), or non-TBM. Xpert MTB/RIF accuracy was evaluated using 1 ml of uncentrifuged and, when available, 3 ml of centrifuged cerebrospinal fluid (CSF). To evaluate the incremental value of MTB/RIF over a clinically based diagnosis, test accuracy was compared to a clinical score (CS) derived using basic clinical and laboratory information. Of 204 evaluable patients (of whom 87% were HIV-infected), 59 had definite TBM, 64 probable TBM, and 81 non-TBM. Overall sensitivity and specificity (95% CI) were 62% (48%-75%) and 95% (87%-99%), respectively. The sensitivity of Xpert MTB/RIF was significantly better than that of smear microscopy (62% versus 12%; p = 0.001) and significantly better than that of the CS (62% versus 30%; p = 0.001; C statistic 85% [79%-92%]). Xpert MTB/RIF sensitivity was higher when centrifuged versus uncentrifuged samples were used (82% [62%-94%] versus 47% [31%-61%]; p = 0.004). The combination of CS and Xpert MTB/RIF (Xpert MTB/RIF performed if CS<8) performed as well as Xpert MTB/RIF alone but with a ∼10% reduction in test usage. This overall pattern of results remained unchanged when the definite and probable TBM groups were combined. Xpert MTB/RIF was not useful in identifying TBM among HIV-uninfected individuals, although the sample was small. There was no evidence of PCR inhibition, and the limit of detection was ∼80 colony forming units per millilitre. Study limitations included a predominantly HIV-infected cohort and the limited number of culture-positive CSF samples. CONCLUSIONS: Xpert MTB/RIF may be a good rule-in test for the diagnosis of TBM in HIV-infected individuals from a tuberculosis-endemic setting, particularly when a centrifuged CSF pellet is used. Further studies are required to confirm these findings in different settings. Please see later in the article for the Editors' Summary.


Asunto(s)
Reacción en Cadena de la Polimerasa/métodos , Tuberculosis Meníngea/diagnóstico , Adulto , Femenino , Humanos , Masculino , Estudios Prospectivos , Tuberculosis Meníngea/genética , Adulto Joven
19.
Biochem Biophys Res Commun ; 431(4): 647-51, 2013 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-23337501

RESUMEN

Tumor resistance to cytotoxic therapeutics coupled with dose-limiting toxicity is a serious hurdle in the field of medical oncology. In the face of this obstacle, nitric oxide has emerged as a powerful adjuvant for the hypersensitization of tumors to more traditional chemo- and radio-therapeutics. Furthermore, emerging evidence indicates that nitric oxide donors have the potential to function independently in the clinical management of cancer. Herein, we discuss the role of nitric oxide in cancer and the potential for nitric oxide donors to support conventional therapeutics.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Resistencia a Antineoplásicos , Neoplasias/tratamiento farmacológico , Donantes de Óxido Nítrico/uso terapéutico , Óxido Nítrico/metabolismo , Apoptosis/efectos de los fármacos , Humanos , Neoplasias/metabolismo , Donantes de Óxido Nítrico/farmacología
20.
J Minim Access Surg ; 9(3): 136-7, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24019694

RESUMEN

Isolated tracheobronchial injuries are extremely rare in children and challenging due to life threatening complications. Blunt trauma to chest, especially in pediatric age group, is usually associated with multi-organ involvement and high mortality rate. These patients rarely reach a hospital. We have described here a case of complete transection of right main bronchus in a child, without hilar vascular injury, and its successful management, emphasizing the role of bronchoscopy and thoracoscopy.

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