首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 906 毫秒
1.
Antitryptic, antichymotryptic and alpha 2- macroglobulin activities were measured in sera of normal nonpregnant and normal pregnant women and women with tubal ectopic pregnancy and molar pregnancies in the first 5 to 7 weeks of pregnancy calculated from the last menstrual period. While alpha 2-macroglobulin decreased in early normal pregnancy compared to nonpregnant state (p<0.001), in ectopic and molar pregnancies there was an increase in alpha 2- macroglobulin activity (p < 0.001), as compared to nonpregnant and normal pregnant women. Antitryptic activity did not increase in normal and ectopic pregnancy, however was increased in molar pregnancy (p < 0.01). Antichymotryptic activities did not show a change either in normal pregnancy or in cases of ectopic and molar pregnancy. Drop in alpha 2- macroglobulin activity to near normal levels in ectopic, 6 weeks post surgery, correlated well with the decrease in β-hCG. However, in molar pregnancy, alpha 2- macroglobulin remained elevated even when the β-hCG levels in serum returned to zero 10 weeks after surgery. The studies suggest a major role for circulating proteinase inhibitors especially alpha 2-macroglobulin in regulating proteinase activity in normal, ectopic and molar pregnancy.  相似文献   

2.
We present an integrated microfluidic chip for detection of β-amyloid (Aβ) peptides. Aβ peptides are major biomarkers for the diagnosis of Alzheimer''s disease (AD) in its early stages. This microfluidic device consists of three main parts: (1) An immunocapture microcolumn based on self-assembled magnetic beads coated with antibodies specific to Aβ peptides, (2) a nano-porous membrane made of photopolymerized hydrogel for preconcentration, and (3) a microchip electrophoresis (MCE) channel with fluorescent detection. Sub-milliliter sample volume is either mixed off-chip with antibody coated magnetic beads and injected into the device or is injected into an already self-assembled column of magnetic beads in the microchannel. The captured peptides on the beads are then electrokinetically eluted and re-concentrated onto the nano-membrane in a few nano-liters. By integrating the nano-membrane, total assay time was reduced and also off-chip re-concentration or buffer exchange steps were not needed. Finally, the concentrated peptides in the chip are separated by electrophoresis in a polymer-based matrix. The device was applied to the capture and MCE analysis of differently truncated peptides Aβ (1–37, 1–39, 1–40, and 1–42) and was able to detect as low as 25 ng of synthetic Aβ peptides spiked in undiluted cerebrospinal fluid (CSF). The device was also tested with CSF samples from healthy donors. CSF samples were fluorescently labelled and pre-mixed with the magnetic beads and injected into the device. The results indicated that Aβ1-40, an important biomarker for distinguishing patients with frontotemporal lobe dementia from controls and AD patients, was detectable. Although the sensitivity of this device is not yet enough to detect all Aβ subtypes in CSF, this is the first report on an integrated or semi-integrated device for capturing and analyzing of differently truncated Aβ peptides. The method is less demanding and faster than the conventional Western blotting method currently used for research.  相似文献   

3.
Genetic sequence and hyper-methylation profile information from the promoter regions of tumor suppressor genes are important for cancer disease investigation. Since hyper-methylated DNA (hm-DNA) is typically present in ultra-low concentrations in biological samples, such as stool, urine, and saliva, sample enrichment and amplification is typically required before detection. We present a rapid microfluidic solid phase extraction (μSPE) system for the capture and elution of low concentrations of hm-DNA (≤1 ng ml−1), based on a protein-DNA capture surface, into small volumes using a passive microfluidic lab-on-a-chip platform. All assay steps have been qualitatively characterized using a real-time surface plasmon resonance (SPR) biosensor, and quantitatively characterized using fluorescence spectroscopy. The hm-DNA capture/elution process requires less than 5 min with an efficiency of 71% using a 25 μl elution volume and 92% efficiency using a 100 μl elution volume.  相似文献   

4.
Nanofluidics has a unique property that ionic conductance across a nanometer-sized confined space is strongly affected by the space surface charge density, which can be utilized to construct electrical read-out biosensor. Based on this principle, this work demonstrated a novel protein sensor along with a sandwich signal enhancement approach. Nanoparticles with designed aptamer onside are assembled in a suspended micropore to form a 3-dimensional network of nanometer-sized interstices, named as nanofluidic crystal hereafter, as the basic sensing unit. Proteins captured by aptamers will change the surface charge density of nanoparticles and thereby can be detected by monitoring the ionic conductance across this nanofluidic crystal. Another aptamer can further enlarge the variations of the surface charge density by forming a sandwich structure (capturing aptamer/protein/signal enhancement aptamer) and the read-out conductance as well. The preliminary experimental results indicated that human α-thrombin was successfully detected by the corresponding aptamer modified nanofluidic crystal with the limit of detection of 5 nM (0.18 μg/ml) and the read-out signal was enhanced up to 3 folds by using another thrombin aptamer. Being easy to graft probe, facile and low-cost to prepare the nano-device, and having an electrical read-out, the present nanofluidic crystal scheme is a promising and universal strategy for protein sensing.  相似文献   

5.
Although β-Fe2O3 has a high theoretical solar-to-hydrogen efficiency because of its narrow band gap, the study of β-Fe2O3 photoanodes for water splitting is elusive as a result of their metastable nature. Raman identification of β-Fe2O3 is theoretically and experimentally investigated in this study for the first time, thus clarifying the debate about its Raman spectrum in the literature. Phase transformation of β-Fe2O3 to α-Fe2O3 was found to potentially take place under laser and electron irradiation as well as annealing. Herein, phase transformation of β-Fe2O3 to α-Fe2O3 was inhibited by introduction of Zr doping, and β-Fe2O3 was found to withstand a higher annealing temperature without any phase transformation. The solar water splitting photocurrent of the Zr-doped β-Fe2O3 photoanode was increased by 500% compared to that of the pure β-Fe2O3 photoanode. Additionally, Zr-doped β-Fe2O3 exhibited very good stability during the process of solar water splitting. These results indicate that by improving its thermal stability, metastable β-Fe2O3 film is a promising photoanode for solar water splitting.  相似文献   

6.
A new microfluidic pump, termed a reflow pump, is designed to operate with a sub-μl sample volume and transport it back and forth between two pneumatically actuated reservoirs through a flow channel typically containing one or more sensor surfaces. The ultimate motivation is to efficiently use the small sample volume in conjunction with convection to maximize analyte flux to the sensor surface(s) in order to minimize sensor response time. In this paper, we focus on the operational properties of the pumps themselves (rather than the sensor surfaces), and demonstrate both two-layer and three-layer polydimethylsiloxane reflow pumps. For the three-layer pump, we examine the effects of reservoir actuation pressure and actuation period, and demonstrate average volumetric flow rates as high as 500 μl/min. We also show that the two-layer design can pump up to 93% of the sample volume during each half period and demonstrate integration of a reflow pump with a single-chip microcantilever array to measure maximum flow rate.  相似文献   

7.
Cell-cell interactions play a key role in regeneration, differentiation, and basic tissue function taking place under physiological shear forces. However, current solutions to mimic such interactions by micro-patterning cells within microfluidic devices have low resolution, high fabrication complexity, and are limited to one or two cell types. Here, we present a microfluidic platform capable of laminar patterning of any biotin-labeled peptide using streptavidin-based surface chemistry. The design permits the generation of arbitrary cell patterns from heterogeneous mixtures in microfluidic devices. We demonstrate the robust co-patterning of α-CD24, α-ASGPR-1, and α-Tie2 antibodies for rapid isolation and co-patterning of mixtures of hepatocytes and endothelial cells. In addition to one-step isolation and patterning, our design permits step-wise patterning of multiple cell types and empty spaces to create complex cellular geometries in vitro. In conclusion, we developed a microfluidic device that permits the generation of perfusable tissue-like patterns in microfluidic devices by directly injecting complex cell mixtures such as differentiated stem cells or tissue digests with minimal sample preparation.  相似文献   

8.
The misfolding of amyloid-β (Aβ) peptides from the natural unfolded state to β-sheet structure is a critical step, leading to abnormal fibrillation and formation of endogenous Aβ plaques in Alzheimer''s disease (AD). Previous studies have reported inhibition of Aβ fibrillation or disassembly of exogenous Aβ fibrils in vitro. However, soluble Aβ oligomers have been reported with increased cytotoxicity; this might partly explain why current clinical trials targeting disassembly of Aβ fibrils by anti-Aβ antibodies have failed so far. Here we show that Au23(CR)14 (a new Au nanocluster modified by Cys-Arg (CR) dipeptide) is able to completely dissolve exogenous mature Aβ fibrils into monomers and restore the natural unfolded state of Aβ peptides from misfolded β-sheets. Furthermore, the cytotoxicity of Aβ40 fibrils when dissolved by Au23(CR)14 is fully abolished. More importantly, Au23(CR)14 is able to completely dissolve endogenous Aβ plaques in brain slices from transgenic AD model mice. In addition, Au23(CR)14 has good biocompatibility and infiltration ability across the blood–brain barrier. Taken together, this work presents a promising therapeutics candidate for AD treatment, and manifests the potential of nanotechnological approaches in the development of nanomedicines.  相似文献   

9.
We describe a scalable artificial bilayer lipid membrane platform for rapid electrophysiological screening of ion channels and transporters. A passive pumping method is used to flow microliter volumes of ligand solution across a suspended bilayer within a microfluidic chip. Bilayers are stable at flow rates up to ∼0.5 μl/min. Phospholipid bilayers are formed across a photolithographically defined aperture made in a dry film resist within the microfluidic chip. Bilayers are stable for many days and the low shunt capacitance of the thin film support gives low-noise high-quality single ion channel recording. Dose-dependent transient blocking of α-hemolysin with β-cyclodextrin (β-CD) and polyethylene glycol is demonstrated and dose-dependent blocking studies of the KcsA potassium channel with tetraethylammonium show the potential for determining IC50 values. The assays are fast (30 min for a complete IC50 curve) and simple and require very small amounts of compounds (100 μg in 15 μl). The technology can be scaled so that multiple bilayers can be addressed, providing a screening platform for ion channels, transporters, and nanopores.  相似文献   

10.
Severe hemolytic anemia in β-thalassemia major and β-thalassemias/HbE (β-TM) patients requires giving blood transfusions. Chronic blood transfusions lead to iron overload consequence with organs damage and risk of alloantibody-formation. This study evaluates the prevalence of red cell alloimmunization and estimates the risk of alloantibody-formation in chronic transfusion-dependent β-TM patients. This cross sectional study was conducted on 143 β-TM patients receiving regular transfusions. We tried to determine the frequency, types and factors influencing red cell alloimmunization in these transfusion-dependent β-TM patients. Median age of 25 (17.5 %) alloantibody-formation β-TM patients was 19.0 years (inter quartile 15.5–24.0 years). The alloantibodies were Anti-Rh (E) (13.1 %), Anti-Rh (D) (0.7 %). Thirty-four patients (23.8 %) of the sample had splenectomies of which 10 (29.4 %) had alloantibody-formation. The interval from first transfusion to antibody development varied from 1.5 to 14 years. Alloantibody-formation correlated with splenectomy and splenectomy correlated with number of transfusion (p < 0.005). In multiple logistic regression used to estimate the risk of alloantibodies formation with splenectomy; OR and 95 % CI were 2.88 (1.07–7.80), p = 0.037 after adjusting for other co-variates. The rate of red cell alloimmunization was 17.5 % and splenectomy associated with increased alloantibody-formation in these transfusion-dependent β-TM patients.  相似文献   

11.
This article describes a fabrication process for the generation of a leak proof paper based microfluidic device and a new design strategy for convenient incorporation of externally prepared test zones. Briefly, a negative photolithographic method was used to prepare the device with a partial photoresist layer on the rear of the device to block the leakage of sample. Microscopy and Field Emission Scanning Electron Microscopy data validated the formation of the photoresist layer. The partial layer of photoresist on the device channel limits sample volume to 7 ± 0.2 μl as compared to devices without the partial photoresist layer which requires a larger sample volume of 10 ± 0.1 μl. The design prototype with a customized external test zone exploits the channel protrusions on the UV exposed photoresist treated paper to bridge the externally applied test zone to the sample and absorbent zones. The partially laminated device with an external test zone has a comparatively low wicking speed of 1.8 ± 0.9 mm/min compared to the completely laminated device with an inbuilt test zone (3.3 ± 1.2 mm/min) which extends the reaction time between the analyte and reagents. The efficacy of the prepared device was studied with colorimetric assays for the non-specific detection of protein by tetrabromophenol blue, acid/base with phenolphthalein indicator, and specific detection of proteins using the HRP-DAB chemistry. The prepared device has the potential for leak proof detection of analyte, requires low sample volume, involves reduced cost of production (∼$0.03, excluding reagent and lamination cost), and enables the integration of customized test zones.  相似文献   

12.
Hemoglobin (Hb) Grey Lynn is a Hb variant caused by a substitution of Phe for Leu at position 91 of α1-globin chain, originally described in individual of unknown ethnic background. This article addresses the interaction of Hb Grey Lynn with a non-deletional α+-thalassemia found in Thailand, a hitherto un-described condition. The proband was adult Thai woman referred for investigation of mild anemia with Hb 90 g/L. Hb analyses using low pressure liquid chromatography raised a suspicion of abnormal Hb presence, which was failed to demonstrate by cellulose acetate electrophoresis and capillary electrophoresis. DNA sequencing identified a CTT (Leu) to TTT (Phe) mutation at codon 91 corresponding to the Hb Grey Lynn (Vientiane) [α91(FG3)Leu>Phe (α1) on α1-globin gene and a C deletion between codons 36 and 37 on α2-globin gene causing α+-thalassemia. As compared to those observed in a compound heterozygote for Hb Grey Lynn / α0-thalassemia reported previously, higher MCV (81.7 fL) and MCH (26.3 pg) values with a lower level of Hb Grey Lynn (19.7%) were observed in the proband. The normochromic normocytic anemia observed could be due to the interaction of Hb Grey Lynn with α+-thalassemia. The two mutations could be identified using PCR-RFLP and allele-specific PCR assays developed.  相似文献   

13.
One puzzling phenomenon in glass physics is the so-called ‘shadow glass transition’ which is an anomalous heat-absorbing process below the real glass transition and influences glass properties. However, it has yet to be entirely characterized, let alone fundamentally understood. Conventional calorimetry detects it in limited heating rates. Here, with the chip-based fast scanning calorimetry, we study the dynamics of the shadow glass transition over four orders of magnitude in heating rates for 24 different hyper-quenched metallic glasses. We present evidence that the shadow glass transition correlates with the secondary (β) relaxation: (i) The shadow glass transition and the β relaxation follow the same temperature–time dependence, and both merge with the primary relaxation at high temperature. (ii) The shadow glass transition is more obvious in glasses with pronounced β relaxation, and vice versa; their magnitudes are proportional to each other. Our findings suggest that the shadow glass transition signals the thermodynamics of β relaxation in hyper-quenched metallic glasses.  相似文献   

14.
Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease which is characterized by dysregulation of various cytokines propagating the inflammatory processes that is responsible for tissue damage. Tumor necrosis factor alpha (TNF-α) is one of the most important immunoregulatory cytokines that has been implicated in the different autoimmune diseases including SLE. Two hundred and two patients with SLE and 318 controls were included in the study. The TNF-α gene promoter region (from − 250 to − 1000 base pairs) was analyzed by direct Sanger’s DNA sequencing method to find promoter variants associated with South Indian SLE patients. We have analyzed six TNF-α genetic polymorphisms including, − 863C/A (rs1800630), − 857C/T (rs1799724), − 806C/T (rs4248158), − 646G/A (rs4248160), − 572A/C (rs4248161) and − 308G/A (rs1800629) in both SLE patients and controls. We did not find association of TNF-α gene promoter SNPs with SLE patients. However, the − 863A (rs1800630) allele showed association with lupus nephritis phenotype in patients with SLE (OR: 1.62, 95%CI 1.04–2.53, P = 0.034). We found serum TNF-α level was significantly elevated in SLE cases as compared to control and found no association with any of the polymorphisms. The haplotype analysis revealed a significant protective association between the wild TNF-α alleles at positions − 863C, − 857C, − 806C, − 646G, − 572A and − 308G (CCCGAG) haplotype with lupus nephritis phenotype (OR 0.53, 95% CI 0.35–0.82, P = 0.004). Additionally, the TNF-α − 863 C/A (rs1800630) polymorphism and HLA-DRB1*07 haplotype showed significant differences between SLE patients and controls (OR 4.79, 95% CI 1.73–13.29, P = 0.0009). In conclusion, TNF-α − 863A allele (rs1800630) polymorphism is associated with increased risk of nephritis in South Indian SLE patients. We also found an interaction between HLA-DRB1*07 allele with TNF-α − 863 C/A promoter polymorphism giving supportive evidence for the tight linkage disequilibrium between TNF-α promoter SNPs and MHC class II DRB1 alleles.  相似文献   

15.
Simple and sensitive Liquid Chromatography-Tandem Mass Spectrometry (LCMS/MS) method was developed and validated, then was implicated on hypertensive human subjects to study drug interaction of atorvastatin (ATVS) and Olmesartan (OLM) on status of Angiotensin-II (ANG-II). The ANG-II in plasma was extracted with 5 mL methanol containing 5 % formic acid through C18 (cartridges) liquid–liquid extraction, dried and reconstituted with 1 mL of 16 % acetonitrile in 0.1 % formic acid in water. The chromatographic separation of ANG-II with a Agilent technology 6410 Triple quadrupole was carried multiple reaction monitoring scan mode with a Agilent 1290 Infinity LC system for UHPLC. The sample were separated on a (Thermo Scientific) Hy-Purity advance (50 × 4.6 mm, 5 μm) using Mobile Phase A: 16 % acetonitrile in 0.1 % formic acid in water and Mobile Phase B: 0.1 % formic acid in methanol at a flow rate of 0.3 mL/min, performed at ambient temperature. The mobile phase gradient of 16 % acetonitrile in water was linearly increased to 38 % acetonitrile over 10 min and subsequently the mobile-phase was increased to 100 % acetonitrile over 15 min. The developed method was validated for specificity, accuracy, precision, stability, linearity, sensitivity and recovery. The method was linear between peak area ratio of standard and internal standard over the range of 50–800 ng/mL. The method was successfully applied for the drug interaction study revealed levels of ANG-II were significantly higher in ATVS + OLM treatment condition as compared to individual treatment of OLM. This reflects the reason of low effectiveness of ATVS + OLM in combination instead of synergistic activity.

Electronic supplementary material

The online version of this article (doi:10.1007/s12291-014-0457-x) contains supplementary material, which is available to authorized users.  相似文献   

16.
In this paper, we present an on-chip hand-powered membrane pump using a robust patient-to-chip syringe interface. This approach enables safe sample collection, sample containment, integrated sharps disposal, high sample volume capacity, and controlled downstream flow with no electrical power requirements. Sample is manually injected into the device via a syringe and needle. The membrane pump inflates upon injection and subsequently deflates, delivering fluid to downstream components in a controlled manner. The device is fabricated from poly(methyl methacrylate) (PMMA) and silicone, using CO2 laser micromachining, with a total material cost of ∼0.20 USD/device. We experimentally demonstrate pump performance for both deionized (DI) water and undiluted, anticoagulated mouse whole blood, and characterize the behavior with reference to a resistor-capacitor electrical circuit analogy. Downstream output of the membrane pump is regulated, and scaled, by connecting multiple pumps in parallel. In contrast to existing on-chip pumping mechanisms that typically have low volume capacity (∼5 μL) and sample volume throughput (∼1–10 μl/min), the membrane pump offers high volume capacity (up to 240 μl) and sample volume throughput (up to 125 μl/min).  相似文献   

17.
The 5th International Conference on Optofluidics (Optofluidics 2015) was held in Taipei, Taiwan, July 26–29, 2015. The aim of this conference was to provide a forum to promote scientific exchange and to foster closer networks and collaborative ties between leading international researchers in optics and micro/nanofluidics across various disciplines. The scope of Optofluidics 2015 was deliberately broad and interdisciplinary, encompassing the latest advances and the most innovative developments in micro/nanoscale science and technology. Topics ranged from fundamental research to its applications in chemistry, physics, biology, materials, and medicine.Approximately 300 delegates participated in Optofluidics 2015 from across the globe, including Australia, Canada, China, France, Germany, Hong Kong, India, Japan, Korea, Singapore, Taiwan, UK, and USA. In total, 242 presentations were arranged, including 10 plenary speeches, 27 keynote speeches, 65 invited talks, 33 contributed talks, and 107 poster presentations. This collection of twelve papers on this special topic spans both the fundamentals and the frontier applications of this interdisciplinary research field.Optical measurements of particle or flow and fluidic manipulation for optical applications were presented. Lin and Su1 reported a novel method to measure the depth position of rapidly moving objects inside a microfluidic channel based on the chromatic aberration effect; the depth positions of label-free particles of diameter as small as 2 μm and erythrocytes of concentration 2 × 103 cells/μl and velocity 2.78 mm/s were detected within a range ±25 μm in a simple and inexpensive manner. Sun and Huang2 demonstrated the use of a microscopic circular polariscope to measure the flow-induced birefringence in a microfluidic device that represents the kinematics of fluid motion optically; CTAB:NaSal, CPyCl:NaSal, and CPyCl:NaSal:NaCl solutions were used to investigate the strain rate and the results were compared with the μPIV diagnosis. He et al.3 studied the fundamentals, especially the thinning and opening of the oil film within each pixel of an electrowetting display; to achieve repeatable oil movement and the resulting pixel performance, a new method to fill each pixel with a controllable oil volume using an oil-droplet emulsion created with a microfluidic device was demonstrated.This special topic includes papers also on particle manipulation. Weng et al.4 evaluated the size-dependent crossing frequency of dielectrophoretically driven particles; numerical simulation using a Maxwell stress tensor and a finite element method was reported to assess the size effect. In addition to electric manipulation, magnetic driving of the particles was demonstrated. Ido et al.5 examined microswimmers of magnetic particle chains in an oscillating magnetic field experimentally and analyzed numerically with a lattice Boltzmann method, an immersed boundary method, and a discrete particle method based on simplified Stokesian dynamics. Huang et al.6 described a technique to manipulate magnetic beads and achieved a great washing efficiency with zero bead loss using an appropriate electrode design and channel height of a digital microfluidic immunoassay; a model immunoassay of human soluble tumor necrosis factor receptor I (sTNF-RI) was performed to offer an improved limit of detection (3.14 pg/ml) with a small number of magnetic beads (25 beads), decreased reagent volumes (200 nl), and decreased duration of analysis (<1 h). Chiu et al.7 reported particle separation using cross-flow filtration enhanced with hydrodynamic focusing; label-free separation of particles of diameters 2.7 and 10.6 μm at a sample throughput 10 μl/min was performed; separation of spiked human prostate cancer cell lines (PC3) cells in whole blood was also demonstrated.Chemical sensors and biosensors are covered in this special topic. Cheng et al.8 measured the chemical compounds in third-hand smoke on varied clothing fibres with an analytical balance, or nicotine and 3-ethenylpyridine (3-EP) with a surface-acoustic-wave sensor composed of coated oxidized hollow mesoporous carbon nanospheres. Pu et al.9 described a continuous glucose monitoring microsystem consisting of a three-electrode electrochemical sensor in which the working electrode (WE) was covered with a single layer of graphene and gold nanoparticles to improve the sensor performance; the results of glucose measurement were linear below concentration 162 mg/dl with a detection limit 1.44 mg/dl. Li et al.10 implemented a microfluidic device measuring the glucose concentration with integrated fibre-optic surface plasmon resonance sensor and electrode pairs for volume quantification.Implantable devices and microneedles for drug delivery and liquid transport are addressed in this special topic. Zhang et al.11 reported a flexible polyimide device seated under rabbit eyelids to deliver drug by iontophoresis; varied currents to release manganese ions (Mn2+) as tracers were investigated; the thermal effect on application of a current was studied. Lee et al.12 presented a disposable Parylene microneedle array of large aspect ratio that vibrated with a piezoelectric actuator to mimic the vibrating motion of a mosquito''s proboscis and to decrease the insertion force by 40%. Song et al.13 demonstrated microinjection into a model organism, Caenorhabditis elegans (C. elegans) on an automated device capable of loading, immobilization, injection, and sorting; with 200 worms studied, injection speed 6.6 worm/min, injection success rate 77.5%, and sorting success rate 100% were obtained.We express our gratitude for the financial support from Ministry of Science and Technology (Taiwan), Bureau of Foreign Trade (Taiwan), National Taiwan University and Research Center for Applied Sciences of Academia Sinica, and for administrative support from Instrument Technology Research Center in making Optofluidics 2015 a successful conference. Our acknowledgements include Leslie Yeo, Frederick Kontur, Christine Urso, and all staff from Biomicrofluidics for their kind assistance during the preparation, and, most importantly, all authors who have contributed their work for this special topic.  相似文献   

18.
The main objective of this study is to evaluate the anti-hypertrophic potential of the aqueous extract of Enicostemma littorale (E. littorale) against isoproterenol induced cardiac hypertrophic rat models (male albino Wistar rats) through biochemical investigations. Aqueous extract of E. littorale known for various beneficial properties was administered (100 mg/kg, 12 days, oral) to isoproterenol (ISO) induced cardiac hypertrophic rats (low ISO—60 mg/kg, 12 days and high ISO—100 mg/kg, 12 days, subcutaneous) and were compared with group that was treated with the reference drug, Losartan (10 mg kg, administered for 12 days, oral). The anti-hypertrophic effect of E. littorale was evaluated by analysing the morphometric indices of the heart, ECG tracings, changes in blood biochemical parameters viz., serum glucose, serum total protein, serum albumin, lipid profile, cardiac specific enzymes (SGOT, SGPT and LDH) and histopathological examination of the heart tissue. The results fundamentally revealed that the plant extract efficiently ameliorated cardiac hypertrophy induced by ISO injected in experimental rats. The outcomes of biochemical investigations of this study highlighted the association between the hypertrophic β-adrenergic receptor signalling (β-AR) and the 5′ AMP-activated protein kinase (AMPK)—peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) axis in the metabolism of cardiac fibrosis and hypertrophy. This β-AR/AMPK-PGC1α signalling stem can serve as a key target in ameliorating cardiac hypertrophy through focus on its principal regulators. To add, we also propose that the glycoside, swertiamarin present in this plant with the reported anti-fibrotic potential in liver can be further isolated and evaluated for its anti-hypertrophic potential to treat cardiac hypertrophy.  相似文献   

19.
Although digital detection of nucleic acids has been achieved by amplification of single templates in uniform microfluidic droplets and widely used for genetic analysis, droplet-based digital detection of proteins has rarely been reported, largely due to the lack of an efficient target amplification method for protein in droplets. Here, we report a key step towards digital detection of proteins using a highly parallel microfluidic droplet approach for single enzyme molecule detection in picoliter droplets via enzyme catalyzed signal amplification. An integrated microfluidic chip was designed for high throughput uniform droplet generation, monolayer droplet collection, incubation, detection, and release. Single β-galatosidase (β-Gal) molecules and the fluorogenic substrate fluorescein di-β-D-galactopyranoside were injected from two separated inlets to form uniform 20 μm droplets in fluorinated oil at a frequency of 6.6 kHz. About 200 000 droplets were captured as a monolayer in a capture well on-chip for subsequent imaging detection. A series of β-Gal solutions at different concentrations were analyzed at the single-molecule level. With no enzyme present, no droplets were found to fluoresce, while brightly fluorescent droplets were observed under single-enzyme molecule conditions. Droplet fluorescence intensity distribution analysis showed that the distribution of enzyme molecules under single-molecule conditions matched well with theoretical prediction, further proving the feasibility of detecting single enzyme molecules in emulsion droplets. Moreover, the population of fluorescent droplets increased as the β-Gal concentration increased. Based on a digital counting method, the measured concentrations of the enzyme were found to match well with input enzyme concentration, establishing the accuracy of the digital detection method for the quantification of β-Gal enzyme molecules. The capability of highly parallel detection of single enzyme molecules in uniform picoliter droplets paves the way to microdroplet based digital detection of proteins.  相似文献   

20.
Methods for assaying lysosomal diseases in dried blood samples are very useful today due to its several advantages related to the stability of samples, its transportation, handled and analysis, and its potential use for newborn screening compared to traditional methods in leucocytes samples. For this reason, it is important to validate these assays before being used in routine laboratory. Because of different in biological markers based on ethnicity, we aimed this study to validation a DBS-based fluorometric assay for measurement of α-l-Iduronidase activity for diagnosis of MPS I patients in Iran. DBS samples were collected from 15 MPS I patients and 60 healthy age matched subjects. Diagnostic value, biological variance and α-l-Iduronidase activity were determined. DBS α-l-Iduronidase activity was significantly higher in male subjects than in female group. Using a cut-off level of 1.08 µmol/spot 20 h, sensitivity and specificity were 100 and 98 %. The linearity of test was proved and we showed that within-run and between run precision were 5.6 and 14.66 %. Measurement of α-l-Iduronidase activity in DBS samples is an accurate test for diagnosis of MPS I and because of its rapid shipping and simplicity to keeping, DBS-based enzyme activity could be considered as a useful diagnostic tool in this disease.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号