166 research outputs found
Pectobacterium atrosepticum biosensor for monitoring blackleg and soft rot disease of potato
Pectobacterium atrosepticum (Pba) is a quarantine and threatening phytopathogen known as the causal agent of blackleg and soft rot disease of potatoes in many areas. Its early detection is then important to have healthy potato tubers and reduce economic losses. Today, conventional methods such as enzyme-linked immunosorbent-assay (ELISA) and polymerase chain reaction (PCR) are typically used for Pba detection, but they are expensive and time-consuming. Here we report on the optimization of an alternative approach based on an electrochemical impedance immunosensor combining a microfluidic module and a microelectrodes array, and having advantages in terms of low cost, ease of use and portability. For validation and for assessing its performance, the lab-on-chip platform has been compared with two standard methods (ELISA and PCR)
Nitric Acid Particles in Cold Thick Ice Clouds Observed at Global Scale: Link with Lightning, Temperature, and Upper Tropospheric Water Vapor
Signatures of nitric acid particles (NAP) in cold thick ice clouds have been derived from satellite observations. Most NAP are detected in the Tropics (9 to 20% of clouds with T less than 202.5 K). Higher occurrences were found in the rare mid-latitudes very cold clouds. NAP occurrence increases as cloud temperature decreases and NAP are more numerous in January than July. Comparisons of NAP and lightning distributions show that lightning is the main source of the NOx, which forms NAP in cold clouds. Qualitative comparisons of NAP with upper tropospheric humidity distributions suggest that NAP play a role in the dehydration of the upper troposphere when the tropopause is colder than 195K
Smile platform: An innovative microfluidic approach for onâchip sample manipulation and analysis in oral cancer diagnosis
Oral cancer belongs to the group of head and neck cancers, and, despite its large diffusion, it suffers from low consideration in terms of prevention and early diagnosis. The main objective of the SMILE platform is the development of a lowâcost device for oral cancer early screening with features of high sensitivity, specificity, and ease of use, with the aim of reaching a large audience of possible users and realizing real prevention of the disease. To achieve this goal, we realized two microfluidic devices exploiting lowâcost materials and processes. They can be used in combination or alone to obtain onâchip sample preparation and/or detection of circulating tumor cells, selected as biomarkers of oral cancer. The realized devices are completely transparent with plugâandâplay features, obtained thanks to a highly customized architecture which enables users to easily use them, with potential for a common use among physicians or dentists with minimal training
Centrifugation force and time alter CASA parameters and oxidative status of cryopreserved stallion sperm
Conventional sperm selection techniques used in ARTs rely on centrifugation steps. To date, the different studies reported on the effects of centrifugation on stallion sperm motility provided contrasting results and do not include effects on mitochondrial functionality and different oxidative parameters. The effects of different centrifugation protocols (300 Ăg for 5â, 300 Ăg for 10â, 1500 Ăg for 5â and 1500 Ăg for 10â vs no centrifugation) on motility and oxidative status in cryopreserved stallion sperm, were analyzed. After centrifugation, almost all motility parameters were significantly altered, as observed by computer-assisted sperm analysis. A polarographic assay of oxygen consumption showed a progressive decrease in mitochondria respiration from the gentlest to the strongest protocol. By laser scanning confocal microscopy, significant reduction of mitochondrial membrane potential, at any tested protocol, and time-dependent effects, at the same centrifugal force, were found. Increased DNA fragmentation index at any tested protocol and time-dependent effects at the same centrifugal force were found, whereas increased protein carbonylation was observed only at the strongest centrifugal force. These results provide more comprehensive understandings on centrifugation-induced effects on cryopreserved stallion sperm and suggest that, even at a weak force for a short time, centrifugation impairs different aspects of equine sperm metabolism and functionality
Comparison of CALIPSO-Like, LaRC, and MODIS Retrievals of Ice Cloud Properties over SIRTA in France and Florida during CRYSTAL-FACE
This study compares cirrus particle effective radius retrieved by a CALIPSO-like method with two similar methods using MODIS, MODI Airborne Simulator (MAS), and GOES imagery. The CALIPSO-like method uses lidar measurements coupled with the split-window technique that uses the infrared spectral information contained at the 8.65-micrometer, 11.15-micrometer and 12.05-micrometer bands to infer the microphysical properties of cirrus clouds. The two other methods, sing passive remote sensing at visible and infrared wavelengths, are the operational MODIS cloud products (referred to by its archival product identifier MOD06 for MODIS Terra) and MODIS retrievals performed by the CERES team at LaRC (Langley Research Center) in support of CERES algorithms; the two algorithms will be referred to as MOD06- and LaRC-method, respectively. The three techniques are compared at two different latitudes: (i) the mid-latitude ice clouds study uses 18 days of observations at the Palaiseau ground-based site in France (SIRTA: Site Instrumental de Recherche par Teledetection Atmospherique) including a ground-based 532 nm lidar and the Moderate Resolution Imaging Spectrometer (MODIS) overpasses on the Terra Platform, (ii) the tropical ice clouds study uses 14 different flight legs of observations collected in Florida, during the intensive field experiment CRYSTAL-FACE (Cirrus Regional Study of Tropical Anvils and cirrus Layers-Florida Area Cirrus Experiment), including the airborne Cloud Physics Lidar (CPL) and the MAS. The comparison of the three methods gives consistent results for the particle effective radius and the optical thickness, but discrepancies in cloud detection and altitudes. The study confirms the value of an active remote-sensing method (CALIPSO-like) for the study of sub-visible ice clouds, in both mid-latitudes and tropics. Nevertheless, this method is not reliable in optically very thick tropical ice clouds
Defective B-cell proliferation and maintenance of long-term memory in patients with chronic granulomatous disease
Background: Chronic granulomatous disease (CGD) is a
primary immune deficiency characterized by a defect in reactive
oxygen species production. Although the effect of CGD mainly
reflects on the phagocytic compartment, B-cell responses are
also impaired in patients with CGD.
Objective: We sought to investigate how defective gp91phox
expression in patients with CGD and CGD carriers might affect
the B-cell compartment and maintenance of long-term memory.
Methods: We studied the B-cell compartment of patients with
CGD in terms of phenotype and ability to produce reactive
oxygen species and proliferate on stimuli differently directed to
the B-cell receptor and Toll-like receptor 9. We further studied
their capacity to maintain long-term memory by measuring
cellular and serologic responses to measles.
Results: We show that the memory B-cell compartment is
impaired among patients with CGD, as indicated by reduced
total (CD191CD271) and resting (CD191CD271CD211)
memory B cells in parallel to increased naive
(CD191CD272IgD1) B-cell frequencies. Data on CGD carriers
reveal that such alterations are related to gp91phox expression.
Moreover, proliferative capabilities of B cells on selective
in vitro stimulation of B-cell receptor or Toll-like receptor 9
pathways were reduced in patients with CGD compared with
those seen in age-matched healthy control subjects. Significantly
lower measles-specific antibody levels and antibody-secreting
cell numbers were also observed, indicating a poor ability to
maintain long-term memory in these patients.
Conclusion: Altogether, our data suggest that patients with
CGD present a defective B-cell compartment in terms of
frequencies of memory B cells, response to in vitro stimulation,
and maintenance of long-term antigen-specific memory
Association between ramucirumab-related hypertension and response to treatment in patients with metastatic gastric cancer
PURPOSE:
Hypertension (HTN) is frequently associated with the use of angiogenesis inhibitors targeting the vascular endothelial growth factor pathway, such as ramucirumab. The aim of this study was to retrospectively evaluate if occurrence of HTN is correlated with response to second line treatment with ramucirumab+paclitaxel for metastatic gastric cancer.
METHODS:
Treatment consisted of ramucirumab 8 mg/kg intravenously (iv) on days 1 and 15, plus paclitaxel 80 mg/m2 iv on days 1, 8, and 15 of a 28-day cycle. Patients received study treatment until disease progression, unacceptable toxicity, or withdrawal of consent.
RESULTS:
Thirty-four patients were retrospectively evaluated. Among these, 6 (17.6%) developed grade 3 ramucirumab-induced HTN. These patients had a better outcome than those with lesser grades events, with a progression-free survival (PFS) of 7.8 months (95% CI 4.4-not reached) versus 4.2 months (95% CI 3.1-5.2) (p=0.001). overall survival (OS) was 11.9 months (95% CI 9.3-not reached) in the grade 3 HTN group, versus 7.2 months (95% CI 5.9-10.1).
CONCLUSIONS:
Despite the small number of patients and the retrospective nature of the data, our analysis showed that occurrence of ramucirumab-related HTN, in particular G3 HTN, predicts response to treatment with ramucirumab+paclitaxel in patients with metastatic gastric cancer
Neurofunctional correlates of attention rehabilitation in Parkinson's disease: an explorative study
The effectiveness of cognitive rehabilitation (CR) in Parkinson's disease (PD) is in its relative infancy, and nowadays there is insufficient information to support evidence-based clinical protocols. This study is aimed at testing a validated therapeutic strategy characterized by intensive computer-based attention-training program tailored to attention deficits. We further investigated the presence of synaptic plasticity by means of functional magnetic resonance imaging (fMRI). Using a randomized controlled study, we enrolled eight PD patients who underwent a CR program (Experimental group) and seven clinically/demographically-matched PD patients who underwent a placebo intervention (Control group). Brain activity was assessed using an 8-min resting state (RS) fMRI acquisition. Independent component analysis and statistical parametric mapping were used to assess the effect of CR on brain function. Significant effects were detected both at a phenotypic and at an intermediate phenotypic level. After CR, the Experimental group, in comparison with the Control group, showed a specific enhanced performance in cognitive performance as assessed by the SDMT and digit span forward. RS fMRI analysis for all networks revealed two significant groups (Experimental vs Control) Ă time (T0 vs T1) interaction effects on the analysis of the attention (superior parietal cortex) and central executive neural networks (dorsolateral prefrontal cortex). We demonstrated that intensive CR tailored for the impaired abilities impacts neural plasticity and improves some aspects of cognitive deficits of PD patients. The reported neurophysiological and behavioural effects corroborate the benefits of our therapeutic approach, which might have a reliable application in clinical management of cognitive defici
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