644 research outputs found
Determining the Effects of Transcranial Direct Current Stimulation on Tinnitus, Depression, and Anxiety: A Systematic Review
(1) Background: Tinnitus is the awareness of a sound in the absence of an external source. It affects around 10–15% of people, a significant proportion of whom also experience symptoms such as depression or anxiety that negatively affect their quality of life. Transcranial direct current stimulation (tDCS) is a technique involving constant low-intensity direct current delivered via scalp electrodes. It is a potential treatment option for tinnitus, as well as tinnitus-related conditions such as depression and anxiety. This systematic review estimates the effects of tDCS on outcomes relevant to tinnitus. In addition, it sheds light on the relationship between stimulation parameters and the effect of tDCS on these outcomes; (2) Methods: Exhaustive searches of electronic databases were conducted. Randomised controlled trials were included if they reported at least one of the following outcomes: tinnitus symptom severity, anxiety, or depression. Where available, data on quality of life, adverse effects, and neurophysiological changes were also reviewed. GRADE was used to assess the certainty in the estimate; (3) Results: Meta-analyses revealed a statistically significant reduction in tinnitus (moderate certainty) and depression (low certainty)-but not anxiety-following active tDCS compared to sham control. Network meta-analyses revealed potential optimal stimulation parameters; (4) Conclusions: The evidence synthesised in this review suggests tDCS has the potential to reduce symptom severity in tinnitus and depression. It further narrows down the number of potentially optimal stimulation parameters
Color Capable Sub-Pixel Resolving Optofluidic Microscope and Its Application to Blood Cell Imaging for Malaria Diagnosis
Miniaturization of imaging systems can significantly benefit clinical diagnosis in challenging environments, where access to physicians and good equipment can be limited. Sub-pixel resolving optofluidic microscope (SROFM) offers high-resolution imaging in the form of an on-chip device, with the combination of microfluidics and inexpensive CMOS image sensors. In this work, we report on the implementation of color SROFM prototypes with a demonstrated optical resolution of 0.66 µm at their highest acuity. We applied the prototypes to perform color imaging of red blood cells (RBCs) infected with Plasmodium falciparum, a particularly harmful type of malaria parasites and one of the major causes of death in the developing world
Counterflow dielectrophoresis for trypanosome enrichment and detection in blood
Human African trypanosomiasis or sleeping sickness is a deadly disease endemic in sub-Saharan Africa, caused by single-celled protozoan parasites. Although it has been targeted for elimination by 2020, this will only be realized if diagnosis can be improved to enable identification and treatment of afflicted patients. Existing techniques of detection are restricted by their limited field-applicability, sensitivity and capacity for automation. Microfluidic-based technologies offer the potential for highly sensitive automated devices that could achieve detection at the lowest levels of parasitemia and consequently help in the elimination programme. In this work we implement an electrokinetic technique for the separation of trypanosomes from both mouse and human blood. This technique utilises differences in polarisability between the blood cells and trypanosomes to achieve separation through opposed bi-directional movement (cell counterflow). We combine this enrichment technique with an automated image analysis detection algorithm, negating the need for a human operator
Genetic Variation in Cell Death Genes and Risk of Non-Hodgkin Lymphoma
Background
Non-Hodgkin lymphomas are a heterogeneous group of solid tumours that constitute the 5th highest cause of cancer mortality in the United States and Canada. Poor control of cell death in lymphocytes can lead to autoimmune disease or cancer, making genes involved in programmed cell death of lymphocytes logical candidate genes for lymphoma susceptibility.
Materials and Methods
We tested for genetic association with NHL and NHL subtypes, of SNPs in lymphocyte cell death genes using an established population-based study. 17 candidate genes were chosen based on biological function, with 123 SNPs tested. These included tagSNPs from HapMap and novel SNPs discovered by re-sequencing 47 cases in genes for which SNP representation was judged to be low. The main analysis, which estimated odds ratios by fitting data to an additive logistic regression model, used European ancestry samples that passed quality control measures (569 cases and 547 controls). A two-tiered approach for multiple testing correction was used: correction for number of tests within each gene by permutation-based methodology, followed by correction for the number of genes tested using the false discovery rate.
Results
Variant rs928883, near miR-155, showed an association (OR per A-allele: 2.80 [95% CI: 1.63–4.82]; pF = 0.027) with marginal zone lymphoma that is significant after correction for multiple testing.
Conclusions
This is the first reported association between a germline polymorphism at a miRNA locus and lymphoma
The effect of 1,3-butanediol and carbohydrate supplementation on running performance
Objectives: Ingested ketogenic agents offer the potential to enhance endurance performance via the provision of an alternative exogenous, metabolically efficient, glycogen-sparing fuel (i.e. ketone bodies). This study aimed to assess the impact of combined carbohydrate and 1,3-butanediol (CHO-BD) supplementation on endurance performance, blood beta-hydroxybutyrate (βHB) concentration and glycolytic activity, in comparison to carbohydrate supplementation alone (CHO). Design: Eleven male runners (age 38 ± 12 years, mass 67.3 ± 6.5 kg, height 174.5 ± 5.0 cm, V̇O2peak 64.2 ± 5.0 ml·kg-1·min-1) performed two experimental trials in a randomised crossover design. Methods: Each trial consisted of 60 min of submaximal running, followed by a 5 km running time-trial (TT), and was performed following the ingestion of an energy matched ~650 ml drink (CHO-BD or CHO). Results: There was no difference in TT completion time between the trials (CHO: 1265 ± 93, CHO-BD: 1261 ± 96 s; p=0.723). However, blood βHB concentration in the CHO-BD trial was at least double that of the CHO trial at all time points following supplementation (p<0.05). While blood lactate concentration was lower in the CHO-BD versus CHO trial after 30 min submaximal exercise (CHO-BD: 1.46 ± 0.67 mmol·L-1, CHO: 1.77 ± 0.46 mmol·L-1, p=0.040), it was similar at other time points. Blood glucose concentrations were higher post-TT in the CHO-BD trial (CHO-BD: 5.83 ± 1.02 mmol·L-1, CHO: 5.26 ± 0.95 mmol·L-1, p=0.015). Conclusions: An energy matched CHO-BD supplementation drink raised βHB concentration and acutely lowered blood lactate concentration, without enhancing 5km TT running performance
Planar digital nanoliter dispensing system based on thermocapillary actuation
We provide guidelines for the design and operation of a planar digital nanodispensing system based on
thermocapillary actuation. Thin metallic microheaters embedded within a chemically patterned glass
substrate are electronically activated to generate and control 2D surface temperature distributions
which either arrest or trigger liquid flow and droplet formation on demand. This flow control is
a consequence of the variation of a liquid’s surface tension with temperature, which is used to draw
liquid toward cooler regions of the supporting substrate. A liquid sample consisting of several
microliters is placed on a flat rectangular supply cell defined by chemical patterning. Thermocapillary
switches are then activated to extract a slender fluid filament from the cell and to divide the filament into
an array of droplets whose position and volume are digitally controlled. Experimental results for the
power required to extract a filament and to divide it into two or more droplets as a function of
geometric and operating parameters are in excellent agreement with hydrodynamic simulations. The
capability to dispense ultralow volumes onto a 2D substrate extends the functionality of microfluidic
devices based on thermocapillary actuation previously shown effective in routing and mixing nanoliter
liquid samples on glass or silicon substrates
Alternative Translocation Breakpoint Cluster Region 5' to BCL-6 in B-cell Non-Hodgkin’s Lymphoma
Chromosomal translocations involving band 3q27 with various different partner chromosomes represent a recurrent cytogenetic abnormality
in B-cell non-Hodgkin’s lymphoma. In a fraction of these translocations,
the chromosomal breakpoint is located within the 5' noncoding region of
the BCL-6 proto-oncogene where the BCL-6 major breakpoint region
(MBR) maps. As a result of the translocation, BCL-6 expression is deregulated by promoter substitution. However, between 30 and 50% of lymphomas with cytogenetically detectable translocations affecting band 3q27
retain a germ-line configuration at the BCL-6 locus. To identify possible
additional breakpoint clusters within 3q27, we cloned a t(3;14)(q27;q32)
lymphoma without MBR rearrangement and found a novel breakpoint
site located between 245 and 285 kb 5' to BCL-6. Breakpoints within this
newly described region, which we called the alternative breakpoint region
(ABR), were found to be recurrent in lymphomas carrying t(3q27) chromosomal translocations but devoid of BCL-6 MBR rearrangements. Comparative analysis of multiple lymphomas carrying rearrangements within
the ABR showed that the breakpoints cluster within a 20-kb distance.
Translocations involving the ABR may juxtapose BCL-6 to distantly
acting, heterologous transcriptional regulatory elements which cause deregulation of the proto-oncogene. The identification of BCL-6 ABR provides new tools for the diagnosis of lymphomas carrying aberrations at
3q27 and deregulated BCL-6 genes
Alternative Translocation Breakpoint Cluster Region 5' to BCL-6 in B-cell Non-Hodgkin’s Lymphoma
Chromosomal translocations involving band 3q27 with various different partner chromosomes represent a recurrent cytogenetic abnormality
in B-cell non-Hodgkin’s lymphoma. In a fraction of these translocations,
the chromosomal breakpoint is located within the 5' noncoding region of
the BCL-6 proto-oncogene where the BCL-6 major breakpoint region
(MBR) maps. As a result of the translocation, BCL-6 expression is deregulated by promoter substitution. However, between 30 and 50% of lymphomas with cytogenetically detectable translocations affecting band 3q27
retain a germ-line configuration at the BCL-6 locus. To identify possible
additional breakpoint clusters within 3q27, we cloned a t(3;14)(q27;q32)
lymphoma without MBR rearrangement and found a novel breakpoint
site located between 245 and 285 kb 5' to BCL-6. Breakpoints within this
newly described region, which we called the alternative breakpoint region
(ABR), were found to be recurrent in lymphomas carrying t(3q27) chromosomal translocations but devoid of BCL-6 MBR rearrangements. Comparative analysis of multiple lymphomas carrying rearrangements within
the ABR showed that the breakpoints cluster within a 20-kb distance.
Translocations involving the ABR may juxtapose BCL-6 to distantly
acting, heterologous transcriptional regulatory elements which cause deregulation of the proto-oncogene. The identification of BCL-6 ABR provides new tools for the diagnosis of lymphomas carrying aberrations at
3q27 and deregulated BCL-6 genes
An excess Ra-226 chronology for deep-sea sediments from Saanich Inlet, British Columbia
To further explore the efficacy of 226Ra(excess) dating for deep-sea sediments, previously dated varve sediments from Saanich Inlet were investigated. Ages obtained using 226Ra(excess) are comparable to the varve ages in the upper 20-25 m of the sedimentary record, but radiometric ages for those sediments older than c. 4000 yr BP are significant underestimates. This results from major changes in sedimentation within Saanich Inlet around 4000 yr BP linked to rising sea levels, with younger sediments characterised by a higher biogenic contribution resulting from the establishment of an anoxic fjord environment. The older sediments were deposited in a shallow water inlet characterised by variable Ra mass balance and non-radiogenic losses. Therefore, while 226Ra(excess) can produce reliable dates, its application may be limited where the relative significance of authigenic and allogenic input and bottom water anoxia have been variable and where closed-system behaviour is compromised
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