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Publication
Journal: Gynecologic Oncology
September/25/2011
Abstract
OBJECTIVE
Fibroblast growth factors (FGF) axis, and in particular FGF2 axis, is an important mitogenic stimulus in endometrial carcinogenesis. hSef is a key inhibitory regulator of FGF signaling and aberrant hSef expression is reported to be present in various human carcinomas. The objective of this study was to investigate the role of hSef in the growth and proliferation of endometrial adenocarcinoma cells and to explore the mechanism that may be involved.
METHODS
Using western blot analysis, we determined the expression of hSef in Ishikawa cells under different conditions. Using luciferase reporter assays and western blot analysis, we detected the effect of hSef on MAPK/ERK-mediated FGF2 signaling. Using MTT, cell counting and colony formation assays, we analyzed the growth and proliferation of Ishikawa cells under different conditions.
RESULTS
We found that the hSef expression was positively regulated by FGF2-induced MAPK/ERK signaling and inversely, hSef expression efficiently inhibited the activity of FGF2-induced MAPK/ERK signaling, indicating the presence of hSef-mediated negative feedback mechanism for FGF signaling in endometrial cancer cells. In addition, we found that MAPK/ERK signaling was essential for the growth and proliferation of endometrial cancer cells in vitro, and hSef expression significantly reduced the cell proliferation.
CONCLUSIONS
hSef expression can inhibit the growth and proliferation of endometrial cancer cells via acting on the FGF2/MAPK/ERK signaling.
Publication
Journal: Scientific Reports
May/20/2017
Abstract
Smartphone fluorescence microscopy has various applications in point-of-care (POC) testing and diagnostics, ranging from e.g., quantification of immunoassays, detection of microorganisms, to sensing of viruses. An important need in smartphone-based microscopy and sensing techniques is to improve the detection sensitivity to enable quantification of extremely low concentrations of target molecules. Here, we demonstrate a general strategy to enhance the detection sensitivity of a smartphone-based fluorescence microscope by using surface-enhanced fluorescence (SEF) created by a thin metal-film. In this plasmonic design, the samples are placed on a silver-coated glass slide with a thin spacer, and excited by a laser-diode from the backside through a glass hemisphere, generating surface plasmon polaritons. We optimized this mobile SEF system by tuning the metal-film thickness, spacer distance, excitation angle and polarization, and achieved ~10-fold enhancement in fluorescence intensity compared to a bare glass substrate, which enabled us to image single fluorescent particles as small as 50 nm in diameter and single quantum-dots. Furthermore, we quantified the detection limit of this platform by using DNA origami-based brightness standards, demonstrating that ~80 fluorophores per diffraction-limited spot can be readily detected by our mobile microscope, which opens up new opportunities for POC diagnostics and sensing applications in resource-limited-settings.
Publication
Journal: NeuroImage
January/22/2009
Abstract
To clarify the topography of the areas representing whole intraoral structures and elucidate bilateral neuronal projection to those areas in the primary somatosensory (S1) cortex, we recorded somatosensory-evoked magnetic fields (SEFs), which reflect the earliest cortical responses to pure tactile stimulation, using magnetoencephalography and a piezo-driven tactile stimulation device. Subjects consisted of 10 healthy male adults. Following tactile stimulation of 6 sites on the oral mucosa (inferior/superior buccal mucosa, posterior/anterior tongue mucosa, and upper/lower lip mucosa), SEFs with a peak latency of 15 ms (1M) were identified bilaterally. In contrast, SEFs with a peak latency of 30 ms following right index finger tactile stimulation were identified only in the contralateral hemisphere. Equivalent current dipoles (ECDs) generating 15 ms components were found along the posterior wall of the central sulcus, bilaterally. The ECD locations for oral mucosa-representing areas were located inferiorly to those for the index finger, with the following pattern of organization from top to bottom along the central sulcus: index finger, upper or lower lip, anterior or posterior tongue and superior or inferior buccal mucosa, with a wide distribution, covering 30% of the S1 cortex. Source strength for 1M in the ipsilateral hemisphere was weaker than that in the contralateral hemisphere. These results clearly indicate that sensory afferents innervating the intraoral region project to both the contralateral and ipsilateral 3b areas via the trigeminothalamic tract, where contralateral projection is predominant. The results clarify the intraoral structure-representing areas in the S1 cortex, adding those areas to the classical "sensory homunculus".
Publication
Journal: Brain Research
May/5/1999
Abstract
The amplitudes of many scalp-recorded evoked potential (EP) deflections are higher in females than in males, and in elderly than in young subjects. Since EPs critically depend on the electric conductivity of the cranium, it is not known whether these differences reflect age- and gender-dependent changes in the intensity of neuronal activation, or changes in the volume conductor. Evoked magnetic fields are not significantly affected by the conductivities of the cranial tissues and therefore reflect more directly the neuronal activation than EPs. We report here on the effects of age and gender on somatosensory evoked fields (SEFs) from the primary somatosensory cortex (SI) in 43 healthy subjects (21 males) aged from 20 to 73 years (males 51+/-18 years, females 51+/-14 years). The intensity of neuronal activation was estimated with equivalent current dipoles (ECDs) found at the peaks of the N20m, P35m and P60m deflections from the left SI after right median nerve stimulation. The peak latencies of N20m and P35m (but not of P60m) were shorter in females than in males. The N20m latency was positively correlated with age in males, but otherwise the latencies did not correlate with age. The ECD amplitudes did not differ between males and females for any of the deflections. The N20m ECD strength showed a significant positive correlation (r=0.39, p<0.01) with age while P35m and P60m ECD strengths did not. The results thus did not disclose gender differences in the activation strengths of the somatosensory cortex, implying that such differences in evoked potentials may possibly be due to gender differences in the volume conductor. On the other hand, the results suggest a slight age-related increase in cortical excitability.
Publication
Journal: Genes Chromosomes and Cancer
May/20/2015
Abstract
Sclerosing epithelioid fibrosarcoma (SEF) is a rare soft tissue tumor exhibiting considerable morphologic overlap with low-grade fibromyxoid sarcoma (LGFMS). Moreover, both SEF and LGFMS show MUC4 expression by immunohistochemistry. While the majority of LGFMS cases are characterized by a FUS-CREB3L1 fusion, both FUS-CREB3L2 and EWSR1-CREB3L1 fusions were recently demonstrated in a small number of LGFMS and SEF/LGFMS hybrid tumors. In contrast, recent studies pointed out that SEF harbor frequent EWSR1 rearrangements, with only a minority of cases showing FUS-CREB3L2 fusions. In an effort to further characterize the molecular characteristics of pure SEF and hybrid SEF/LGFMS lesions, we undertook a clinicopathologic, immunohistochemical and genetic analysis of a series of 10 SEF and 8 hybrid SEF/LGFMS tumors. The mortality rate was similar between the two groups, 44% within the pure SEF group and 37% in the hybrid SEF/LGFMS with a mean overall follow-up of 66 months. All but one pure SEF and all hybrid SEF/LGFMS-tested cases showed MUC4 immunoreactivity. The majority (90%) of pure SEF cases showed EWSR1 gene rearrangements by fluorescence in situ hybridization with only one case exhibiting FUS rearrangement. Of the nine EWSR1 positive cases, six cases harbored CREB3L1 break-apart, two had CREB3L2 rearrangement (a previously unreported finding) and one lacked evidence of CREB3L1/2 abnormalities. In contrast, all hybrid SEF/LGFMS tumors exhibited FUS and CREB3L2 rearrangements. These results further demarcate a relative cytogenetic dichotomy between pure SEF, often characterized by EWSR1 rearrangements, and hybrid SEF/LGFMS, harboring FUS-CREB3L2 fusion; the latter group recapitulating the genotype of LGFMS.
Publication
Journal: BMC Biology
September/16/2017
Abstract
Similar to other eukaryotes, splicing is emerging as an important process affecting development and stress tolerance in plants. Ski-interacting protein (SKIP), a splicing factor, is essential for circadian clock function and abiotic stress tolerance; however, the mechanisms whereby it regulates flowering time are unknown.
In this study, we found that SKIP is required for the splicing of serrated leaves and early flowering (SEF) pre-messenger RNA (mRNA), which encodes a component of the ATP-dependent SWR1 chromatin remodeling complex (SWR1-C). Defects in the splicing of SEF pre-mRNA reduced H2A.Z enrichment at FLC, MAF4, and MAF5, suppressed the expression of these genes, and produced an early flowering phenotype in skip-1 plants.
Our findings indicate that SKIP regulates SWR1-C function via alternative splicing to control the floral transition in Arabidopsis thaliana.
Publication
Journal: Seminars in Cell and Developmental Biology
May/20/2016
Abstract
Fibroblast growth factor (FGF) signaling is involved in a multitude of biological processes, while impairment of FGF signaling is implicated in a variety of human diseases including developmental disorders and cancer. Therefore, it is not surprising that FGF activity is regulated at multiple and distinct levels. This review focuses on positive and negative modulation of the FGF signal exemplified by recently identified protein modulators anosmin-1, fibronectin-leucine-rich transmembrane protein 3 (FLRT3) and similar expression to FGF (Sef). We examine how these proteins regulate FGF signaling at multiple levels and across species. Finally, we describe the role of these regulators in human disease.
Publication
Journal: The Angle orthodontist
July/1/2013
Abstract
OBJECTIVE
To study the shear bond strength (SBS), sites of failure, and micromorphology of bonded molar tubes used on teeth affected by dental fluorosis.
METHODS
This in vitro study included 140 first molars classified according to Dean's index for dental fluorosis. Samples were divided into seven groups: (1) healthy teeth etched for 15 seconds, (2) teeth with moderate fluorosis (MOF) etched for 15 seconds, (3) teeth with MOF etched for 150 seconds, (4) teeth with MOF microabrasion etched for 15 seconds, (5) teeth with severe fluorosis (SEF) etched for 15 seconds, (6) teeth with SEF etched for 150 seconds, and (7) teeth with SEF microabrasion etched for 15 seconds. All samples were incubated and were then submitted to the SBS test and evaluated with the modified adhesive remnant index (ARI) and analyzed by using a scanning electronic microscope.
RESULTS
The SBS mean value for healthy enamel was 20 ± 10.2 MPa. For the group with MOF, the etched 150-second mean value was the highest (19 ± 7.6 MPa); for the group with SEF treated with microabrasion and etched for 15 seconds, the mean value was (13 ± 4.1 MPa). Significant differences (P ≤ .05) were found in the ARI between healthy and fluorosed groups.
CONCLUSIONS
Fluorotic enamel affects the adhesion of bonded molar tubes. The use of overetching in cases of MOF and the combination of microabrasion and etching in SEF provides a suitable adhesion for fixed appliance therapy.
Publication
Journal: Journal of Parenteral and Enteral Nutrition
March/17/1992
Abstract
Dipeptides have been reported to be more efficiently absorbed from the gastrointestinal tract than free amino acids. The objective of this study was to compare prospectively a peptide enteral formula (PEF) with a standard enteral formula (SEF) for tolerance and nutritional outcome in acutely injured, hypoalbuminemic (less than 3.0 g/dL) patients who require enteral nutrition support. The prevalence of diarrhea and elevated gastric residuals was assessed daily. Prealbumin, transferrin, colloid oncotic pressure, Prognostic Nutritional Index, and nitrogen balance were measured on days 0, 5, and 10 of enteral nutrition support. Forty-one patients received 345 days of enteral nutrition support. Prevalences of diarrhea and elevated gastric residuals were similar between groups. Prealbumin increased and the Prognostic Nutritional Index decreased significantly from baseline at day 10 in both groups. Transferrin increased in both groups, but not significantly. Colloid oncotic pressure increased significantly from baseline at days 5 and 10 in the SEF group and day 10 in the PEF group. Nitrogen balance increased significantly from baseline at days 5 and 10 in each group. The only significant difference between groups was for nitrogen balance at day 10, which was higher in the SEF group. We conclude based upon our selected measurements of tolerance and nutritional outcome PEF seems to offer no advantage over SEF in acutely injured, hypoalbuminemic patients.
Publication
Journal: Pediatric Research
February/7/2001
Abstract
Adverse perinatal events affecting cerebral functions are a major cause of neonatal mortality, morbidity, and long-term neurologic deficit. Intrapartum fetal EEG, which records fetal brain electrical activity, provides a monitoring modality for evaluating the fetal CNS during labor. In this study, we describe a new approach to such monitoring that is based on real-time spectral analysis of the fetal EEG during labor. Fourteen pregnant women with uncomplicated term pregnancies who went into labor participated in the study. Two suction-cup electrodes were applied to the fetal scalp at the occipitoparietal or parietal region after rupture of membranes. Real-time spectral analysis was used to determine the frequency and amplitude of the fetal EEG signal. The spectral edge frequency (SEF) was calculated as the frequency below which 90% of the power in the power spectrum resides. The average EEG amplitude and the SEF were displayed using the density spectral array technique. Fetal heart rate and intrauterine pressure were also measured. Two fundamental EEG patterns were identified: high-voltage slow activity and low-voltage fast activity. The SEF was found to be an excellent index of cyclic EEG activity. Fetal heart rate demonstrated increased variability and an elevated baseline during low-voltage fast activity, whereas both parameters decreased during high-voltage slow activity. During episodes of variable decelerations in the fetal heart rate, a decrease in the SEF was observed, accompanied by an increased EEG voltage. The results obtained substantiate the presence of sleep cycles in the human fetus. This kind of cortical activity monitoring may enable rapid alertness to cerebral hypoxia and allow for prompt intervention, thereby decreasing the risk for birth asphyxia and subsequent brain damage.
Publication
Journal: Annals of Diagnostic Pathology
December/11/2011
Abstract
Low-grade fibromyxoid sarcoma (LGFMS) is an uncommon tumor with diverse histopathologic features. It has been found to be histopathologically and genetically related to hyalinizing spindle cell tumor with giant rosettes. Lately, sclerosing epithelioid fibrosarcoma (SEF) has been identified as another rare variant of fibrosarcoma. Very few studies have addressed the aspect of its histopathologic relationship with LGFMS. The present study was conducted to critically analyze the clinicopathologic features of a series of LGFMS cases, including identification of cases with histopathologic similarity with SEF. During a 7-year period, 18 LGFMS cases were diagnosed in 9 male and 9 female patients, had ages ranging from 10 to 69 years (median, 32.5 years), and were most commonly identified in the lower extremities (8 cases, or 44.4%). Most cases (16, 88.8%) showed "classic" features of LGFMS with mild (13 cases, or 72.2%) to moderate atypia (5 cases) and nil mitosis (12 cases, or 66.6 %). Variable features included whorling tumor growth pattern, small rosettes, perivascular hyalinization, and amianthoid-like collagen, along with epithelioid differentiation and nuclear pseudoinclusions within tumor cells. Four cases (22.2%) with large collagenous rosettes were diagnosed as hyalinizing spindle cell tumor with giant rosettes. Distinct SEF-like areas were observed in 6 cases (33.3%). On immunohistochemistry, consistent vimentin positively reinforced fibroblastic lineage of the tumor. Therapeutically, all 4 of 7 cases with available follow-up details, which underwent wide excisions, have been free of disease at 5 to 61 months. Eight excisions with unclear margins included 3 cases free of disease (24, 36, and 52 months) and 1 case with recurrence and metastasis. Two cases of marginal excision had tumor recurrences, including 1 case that recurred after 10 years. Low-grade fibromyxoid sarcoma is an uncommon sarcoma with diverse histopathologic features. Histopathologic relationship exists between LGFMS and SEF in a few cases. An LGFMS is optimally managed with surgical wide excision and follow-up.
Publication
Journal: Journal of Athletic Training
May/30/2017
Abstract
OBJECTIVE
To offer an overview of sport-related concussion (SRC) prevention and education strategies in the context of the socioecological framework (SEF). Athletic trainers (ATs) will understand the many factors that interact to influence SRC prevention and the implications of these interactions for effective SRC education.
BACKGROUND
Concussion is a complex injury that is challenging to identify and manage, particularly when athletes fail to disclose symptoms to their health care providers. Education is 1 strategy for increasing disclosure. However, limited information addresses how ATs can integrate the many factors that may influence the effectiveness of SRC education into their specific settings. Public health models provide an example through the SEF, which highlights the interplay among various levels of society and sport that can facilitate SRC prevention strategies, including education.
METHODS
For ATs to develop appropriate SRC prevention strategies, a framework for application is needed. A growing body of information concerning SRC prevention indicates that knowledge alone is insufficient to change concussion-related behaviors. The SEF allows this information to be considered at levels such as policy and societal, community, interpersonal (relationships), and intrapersonal (athlete). The use of such a framework will facilitate more comprehensive SRC prevention efforts that can be applied in all athletic training practice settings. Clinical Applications: Athletic trainers can use this information as they plan SRC prevention strategies in their specific settings. This approach will aid in addressing the layers of complexity that exist when developing a concussion-management policy and plan.
Publication
Journal: Nature Communications
March/29/2019
Abstract
Neuroimaging modalities such as MRI and EEG are able to record from the whole brain, but this comes at the price of either limited spatiotemporal resolution or limited sensitivity. Here, we show that functional ultrasound imaging (fUS) of the brain is able to assess local changes in cerebral blood volume during cognitive tasks, with sufficient temporal resolution to measure the directional propagation of signals. In two macaques, we observed an abrupt transient change in supplementary eye field (SEF) activity when animals were required to modify their behaviour associated with a change of saccade tasks. SEF activation could be observed in a single trial, without averaging. Simultaneous imaging of anterior cingulate cortex and SEF revealed a time delay in the directional functional connectivity of 0.27 ± 0.07 s and 0.9 ± 0.2 s for both animals. Cerebral hemodynamics of large brain areas can be measured at high spatiotemporal resolution using fUS.
Publication
Journal: British Journal of Health Psychology
November/13/2018
Abstract
OBJECTIVE
Health care professionals and the health care environment play a central role in protecting pregnant and post-partum women and their infants from smoking-related harms. This study aimed to better understand the health professional's perspective on how interactions between women, health care professionals, and the environment influence how smoking is managed.
METHODS
Semi-structured interviews and focus groups.
METHODS
Data were from 48 health care staff involved in antenatal or post-partum care at two UK sites, including midwives, obstetricians, health visitors, GPs, pharmacists, service commissioners, and Stop Smoking Service (SSS) advisors and managers. Thematic analysis was guided by a social-ecological framework (SEF).
RESULTS
Themes were divided across three SEF levels and represented factors connected to the management of smoking in the health care context and the beliefs and behaviour of pregnant or post-partum smokers. Organizational level: Service reconfigurations, 'last resort' nicotine replacement therapy prescribing policies, and non-mandatory training were largely negative factors. There were mixed views on opt-out referral pathways and positive views on carbon monoxide monitoring. Interpersonal level: Protection of client-professional relationships often inhibited frank discussions about smoking, and weak interservice relationships affected SSS referral motivation and quality. Individual level: Professionals felt community midwives had primary responsibility for managing smoking, although midwives felt underskilled doing this. Midwives' perceived priority for addressing smoking was influenced by the demands from unrelated organizational initiatives.
CONCLUSIONS
Opportunities to improve clinical support for pregnant smokers exist at organizational, interservice, and health care professional levels. Interactions between levels reflect the importance of simultaneously addressing different level-specific barriers to smoking cessation in pregnancy. Statement of contribution What is already known on this subject? Few health care professionals discuss smoking cessation support with pregnant or post-partum women. Identified health care professional-related barriers to supporting pregnant and post-partum women to stop smoking include deficits in knowledge and confidence, perceived lack of time, and concerns about damaging client relationships. There is currently a gap in understanding regarding the barriers and facilitators to supporting this group and how interactions between the health care environment and health care professionals influence the way smoking is addressed. What does this study add? This study identifies modifiable factors that can influence cessation support delivery to pregnant and post-partum women. These factors are mapped across organizational, interpersonal, and individual health care professional levels. Service structure, communication pathways, and policies appear to influence what cessation support is offered. Interpersonal and individual factors influence how this support is delivered.
Publication
Journal: Paediatric Anaesthesia
March/30/2008
Abstract
BACKGROUND
The characteristics of the electroencephalogram (EEG) during anesthesia in children are poorly described. An understanding of the EEG during anesthesia may help explain and predict the performance of EEG-derived depth of anesthesia monitors in children. This study aims to describe the association between age and some basic characteristics of the EEG during nonstandardized anesthesia in children and infants.
METHODS
Sixty-four children aged 9 days to 12 years were enrolled in this observational physiological study. Anesthesia was given at the discretion of the anesthetist. EEG was recorded from after induction to emergence using a BRM2 brain monitor ''BrainZ Instruments, Auckland, New Zealand'' in parietal and frontal montages. For comparison, 90% spectral edge frequency (SEF-90) and power were determined at three points (equilibrium during anesthesia, when the volatile agent was discontinued and at emergence), and children were divided into three age groups (0-6 months, 6-24 months and 2-12 years).
RESULTS
Fifty-seven children had artifact-free EEG data. From equilibrium to emergence the mean forehead power decreased substantially in children aged 2-12 years (3171-153 microV(2), P < 0.001) and 6-24 months (756-140 microV(2), P < 0.001) but no difference was found in infants aged 0-6 months (93-63 microV(2), P = 0.4). From equilibrium to emergence mean forehead spectral edge frequency increased in children aged 2-12 years (10.8-13.7 Hz, P = 0.01) but no change was found in children aged 6-24 months (12.7-12.7 Hz, P = 0.9) or 0-6 months (9.45-7.26 Hz, P = 0.08). Throughout emergence, infants demonstrated a discontinuous EEG pattern with intermittent bursts separated with low amplitude.
CONCLUSIONS
During anesthesia, the EEG in infants is fundamentally different from the EEG in older children. This study supports the need for specific infant-derived algorithms if EEG-derived anesthesia depth monitors are to be used in infants.
Publication
Journal: Journal of Gastroenterology
January/23/2008
Abstract
BACKGROUND
Sinusoidal endothelial fenestrae (SEF) regulate the sinusoidal circulation by altering their diameter and number. This study documented the effects of endothelin (ET) receptor antagonists on SEF and hepatic microcirculation.
METHODS
The portal pressure and hepatic tissue blood flow were measured with a hydromanometer and a laser Doppler blood flow meter, respectively. BQ-123 (ET(A) receptor antagonist) or BQ-788 (ET(B) receptor antagonist) was continuously infused into normal rats at the rate of 10 nmol/min for 10 min. The sinusoids were observed at 60 min after the infusion by scanning electron microscopy. The localization of ET-1 and ET(A) and ET(B) receptors was examined by the indirect immunoperoxidase method.
RESULTS
When BQ-123 was infused, the portal pressure gradually decreased with time, and it showed a significant reduction compared with the control groups. On the other hand, a decrease in portal pressure was not evident in the BQ-788-infused groups. Hepatic tissue blood flow was maintained at the value prior to the infusion in both groups. BQ-123 also caused a marked dilatation of the SEF. The diameters of the SEF after BQ-123 infusion were almost three times those of normal SEF. ET-1 was evenly present along the sinusoidal walls, and the reaction products of the ET(A) receptors were recognized along the portal vein and in the sinusoidal cells, that is, the hepatic stellate cells and endothelial cells.
CONCLUSIONS
Action of ET-1 via the ET(A) receptors may regulate the size of SEF in addition to hepatic microcirculation.
Publication
Journal: Hepatology Research
March/2/2015
Abstract
Endothelin (ET)-1, a potent vasoconstrictor, is involved in the contraction of hepatic sinusoidal endothelial fenestrae (SEF) through ET-1 receptors. To clarify the role of each receptor (R) in ET-1 induced contraction of SEF, we studied the size of hepatic SEF under various experimental conditions. Scanning electron microscopy was used for morphometric analysis of the fenestrae of sinusoidal endothelial cells isolated from male Wistar rats under the following conditions: (1) control, (2) ET-1, (3) Bosentan (ET(A)-R+ET(B)-R antagonist)right arrowET-1, (4) BQ485 (ET(A)-R antagonist)right arrowET-1, (5) BQ788 (ET(B)-R antagonist)right arrowET-1. Each experiment was based on the observations of 200--205 fenestrae (15--20 fenestrae per cell, two cells per dish and six dishes). The diameter of the endothelial pores of the isolated sinusoidal endothelial cells was 123plus minus35 nm in group (1), 46plus minus21 nm in group (2), 130plus minus40 nm in group (3), 72plus minus28 nm in group (4), and 130plus minus27 nm in group (5). The differences between groups (2) and (4), and between groups (2) and (5), were statistically significant (P<0.05, P<0.01, respectively). Endothelin B receptor (ET(B)-R) antagonist pretreatment abolished the ET-1-induced contraction of SEF, whereas endothelin A receptor (ET(A)-R) antagonist pretreatment appeared to partially block this contraction. The present findings indicate that ET(B)-R plays a primary role in endothelin-1 induced SEF morphological changes, while ET(A)-R plays a subsidiary role.
Publication
Journal: Investigative Ophthalmology and Visual Science
June/8/2008
Abstract
OBJECTIVE
To determine whether retinal branch arteries of healthy persons in different age groups show different longitudinal vessel profiles at baseline and during dynamic reaction to flicker stimulation.
METHODS
Thirty-three healthy subjects (age groups: 21-27 years, 40-59 years, and 60-85 years) were examined with the use of a retinal vessel analyzer. A monochromatic flicker of 12.5 Hz was applied for 60 seconds. Arterial diameters were measured in vessel segments of 1 mm in length to obtain the longitudinal vessel profile. Differences in amplitude and frequency of arterial width changes were characterized by the parameter spectral edge frequency (SEF).
RESULTS
SEF was significantly different between the young group and the senior group in each phase of the arterial reaction to flicker (baseline, dilation, constriction, relaxation; P < 0.05; Mann-Whitney U test). No significant difference within any age group was found in any phase of the arterial reaction. No significant difference between the middle-aged and either young or elderly subjects was found at baseline. However, after stimulation, the middle-aged group displayed a significant difference compared with the young group, with values resembling those of the elderly group.
CONCLUSIONS
In healthy elderly subjects, retinal arteries assumed a significantly less regular longitudinal vessel profile than those of young subjects. Middle-aged subjects assumed a more irregular profile only in the stimulated states of dilation, constriction, and relaxation. Early age-related changes in vessel profile are noted only after metabolic demand. These changes might be a cause for impaired blood flow and blood-vessel wall interaction.
Publication
Journal: Journal of Environmental Management
August/19/2012
Abstract
The goal of this study was to evaluate the suitability of the hilA, agfA, spvC and sef genes amplification by PCR as a method for detection of Salmonella strains. Twenty nine isolates of Salmonella spp. including 6 different serotypes were analyzed in this study. The bacteria were isolated between 2005 and 2007 and serotyped at the Clinical Hospital of Infectious Disease, Cluj-Napoca. Ten non-Salmonella strains were also tested by the same procedure. We used a direct PCR technique, DNA extraction had been skipped and the bacterial cell wall denaturated in the first step of the reaction. All Salmonella strains gave positive results by the PCR amplification of hilA gene. The utilization of the sef, and spvC genes or spvC and agfA genes in a multiplex PCR provides a valuable diagnostic tool for Salmonella enteritidis strains.
Publication
Journal: Neuroscience
October/16/2013
Abstract
Corticokinematic coherence (CKC) refers to coupling between magnetoencephalographic (MEG) brain activity and hand kinematics. For voluntary hand movements, CKC originates mainly from the primary sensorimotor (SM1) cortex. To learn about the relative motor and sensory contributions to CKC, we recorded CKC from 15 healthy subjects during active and passive right index-finger movements. The fingertip was either touching or not touching table, resulting in active-touch, active-no-touch, passive-touch, and passive-no-touch conditions. The kinematics of the index-finger was measured with a 3-axis accelerometer. Beamformer analysis was used to locate brain activations for the movements; somatosensory-evoked fields (SEFs) elicited by pneumatic tactile stimulation of the index finger served as a functional landmark for cutaneous input. All active and passive movements resulted in statistically significant CKC at the movement frequency (F0) and its first harmonic (F1). The main CKC sources at F0 and F1 were in the contralateral SM1 cortex with no spatial differences between conditions, and distinct from the SEF sources. At F1, the coherence was by two thirds stronger for passive than active movements, with no difference between touch vs. no-touch conditions. Our results suggest that the CKC occurring during repetitive finger movements is mainly driven by somatosensory, primarily proprioceptive, afferent input to the SM1 cortex, with negligible effect of cutaneous input.
Publication
Journal: Gastroenterology Research and Practice
August/23/2017
Abstract
Background. The value of endoscopy in dyspeptic patients is questionable. Aims. To examine the prevalence of significant endoscopic findings (SEFs) and the utility of alarm features and age in predicting SEFs in outpatients with dyspepsia. Methods. A retrospective analysis of outpatient adults who had endoscopy for dyspepsia. Demographic variables, alarm features, and endoscopic findings were recorded. We defined SEFs as peptic ulcer disease, erosive esophagitis, malignancy, stricture, or findings requiring specific therapy. Results. Of 650 patients included in the analysis, 51% had a normal endoscopy. The most common endoscopic abnormality was nonerosive gastritis (29.7%) followed by nonerosive duodenitis (7.2%) and LA-class A esophagitis (5.4%). Only 10.2% had a SEF. Five patients (0.8%) had malignancy. SEFs were more likely present in patients with alarm features (12.6% versus 5.4%, p = 0.004). Age ≥ 55 and presence of any alarm feature were associated with SEFs (aOR 1.8 and 2.3, resp.). Conclusion. Dyspeptic patients have low prevalence of SEF. The presence of any alarm feature and age ≥ 55 are associated with higher risk of SEF. Endoscopy in young patients with no alarm features has a low yield; these patients can be considered for nonendoscopic approach for diagnosis and management.
Publication
Journal: NeuroImage
November/20/2003
Abstract
The general spatiotemporal covariance matrix of the background noise in MEG/EEG signals is huge. To reduce the dimensionality of this matrix it is modeled as a Kronecker product of a spatial and a temporal covariance matrix. When the number of time samples is larger than, say, J = 500, the iterative Maximum Likelihood estimation of these two matrices is still too time-consuming to be useful on a routine basis. In this study we looked for methods to circumvent this computationally expensive procedure by using a parametric model with subject-dependent parameters. Such a model would additionally help with interpreting MEG/EEG signals. For the spatial covariance, models have been derived already and it has been shown that measured MEG/EEG signals can be understood spatially as random processes, generated by random dipoles. The temporal covariance, however, has not been modeled yet, therefore we studied the temporal covariance matrix in several subjects. For all subjects the temporal covariance shows an alpha oscillation and vanishes for large time lag. This gives rise to a temporal noise model consisting of two components: alpha activity and additional random noise. The alpha activity is modeled as randomly occurring waves with random phase and the covariance of the additional noise decreases exponentially with lag. This model requires only six parameters instead of 12 J(J + 1). Theoretically, this model is stationary but in practice the stationarity of the matrix is highly influenced by the baseline correction. It appears that very good agreement between the data and the parametric model can be obtained when the baseline correction window is taken into account properly. This finding implies that the background noise is in principle a stationary process and that nonstationarities are mainly caused by the nature of the preprocessing method. When analyzing events at a fixed sample after the stimulus (e.g., the SEF N20 response) one can take advantage of this nonstationarity by optimizing the baseline window to obtain a low noise variance at this particular sample.
Publication
Journal: Human Brain Mapping
April/8/2003
Abstract
Activation of peripheral mixed and cutaneous nerves activates a distributed cortical network including the second somatosensory cortex (SII) in the parietal operculum. SII activation has not been previously reported in the stimulation of the dorsal penile nerve (DPN). We recorded somatosensory evoked fields (SEFs) to DPN stimulation from 7 healthy adults with a 122-channel whole-scalp neuromagnetometer. Electrical pulses were applied once every 0.5 or 1.5 sec to the left and right DPN. For comparison, left and right median and tibial nerves were stimulated alternatingly at 1.5-sec intervals. DPN stimuli elicited weak, early responses in the vicinity of responses to tibial nerve stimulation in the primary somatosensory cortex. Strong later responses, peaking at 107-126 msec were evoked in the SII cortices of both hemispheres, with left-hemisphere dominance. In addition to tactile processing, SII could also contribute to mediating emotional effects of DPN stimuli.
Publication
Journal: NeuroReport
July/16/2000
Abstract
In animals simple passive co-activation causes a fusion and expansion of the involved cortical representations. We used passive tactile finger co-activation for 40 min to investigate cortical representational changes in the human somatosensory cortex. Magnetic source imaging revealed that the euclidean distance between median and ulnar nerve somatosensory evoked fields (SEF) was significantly reduced after application of 600 synchronous airpuff stimuli to the fingertips of four fingers. In the control experiment without co-activation no significant change in distance was observed. Perception threshold and spatial two-point discrimination were not affected by the synchronous stimulation. This is in contrast to blind three-finger Braille readers who frequently mislocalize stimuli applied to the reading fingers. This points to a lack of behavioural relevance or the short duration of co-activation.
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