Correlation of Measurements From Doppler Ultrasound and Optical Coherence Tomography in Glaucoma.

OBJECTIVES: To relate the changes in ocular structure and hemodynamic response in primary open-angle glaucoma (POAG). METHODS: Patients with POAG (n = 46) and control subjects (n = 53) were recruited. Retinal nerve fiber layer and ganglion cell complex were evaluated using optical coherence tomography (OCT). Blood flow was characterized in ophthalmic artery (OA) and central retinal artery (CRA) using color Doppler ultrasonography (CDU), and resistivity index (RI) was calculated. Measurements from CDU and OCT were statistically correlated and the degree of the association was examined. Receiver operating characteristics was produced based on RI and optimal threshold was determined. RESULTS: In POAG patients, OCT revealed neuronal damage and CDU indicated increased resistance to arterial flow. Flow dynamics correlated negatively with the ocular tissue dimensions, sufficiently establishing an association between the ocular structure and its hemodynamic response. Based on the possibility of indirect POAG diagnosis with CDU, threshold 0.7 for RI of OA yielded 73.9% sensitivity and 77.4% specificity in distinguishing the cases of POAG from the controls. Threshold of 0.66 for RI of CRA, had higher specificity of 83%, but lower sensitivity of 52.1%. CONCLUSIONS: Ocular flow exhibits different characteristics in individuals with POAG than normal. The changes associated with the underlying neuronal structure, suggesting the possibility of a potential new diagnostic biomarker for POAG. This justifies further studies with a larger cohort, examining the ocular flow with CDU in POAG and comparing it against OCT findings for establishing the power of CDU in differential diagnosis or glaucoma progression.

Interference of gadolinium dechelated from MR contrast agents by calcium signaling in neuronal cells of GnRH.

Contrast agents (CAs) used in magnetic resonance imaging (MRI) are produced by chelating the metal gadolinium (Gd) with organic ligand molecules to form stable complexes. But, Gd3+ may dissociate from the CAs and subsequently might become toxic to its environment. Besides toxicity, it might inhibit calcium channels on cell membranes and this action could be detrimental to the cells governing biological development. The aim of this study was to investigate the interference of Gd3+ dechelated from the CAs by calcium signaling in the neuronal cells of gonadotropin-releasing hormone (GnRH), regulating puberty, and sexual development. The study used the mouse GT1-7 cell line as a model system, and Fura-2 based calcium imaging for detecting the interruption of intracellular calcium transport by the extracellular presence of Gd3+ as released from the CAs; gadodiamide and gadoterate meglumine, when the cells were stimulated in vitro culture by exposure to melatonin.The CA gadoterate meglumine interfered minimally with the calcium signaling, and thus its use is preferable in standard MRI exams. The release of Gd3+ from gadodiamide was significant and becomes of great concern as it may impact the neurophysiology of the neuronal cells in general, and gonadotropin production in particular, even in normal patients without nephrogenic systemic fibrosis. The toxicity induced by the influx of dechelated Gd3+ in the neurons of GnRH would have significant implications for puberty and reproductive functions.

Sonoelastic response of median nerve to rehabilitation in carpal tunnel syndrome.

Aim of the study: To evaluate the sonoelastic response of the median nerve in patients with carpal tunnel syndrome following conservative rehabilitation with splint plus exercise regimens. Materials and methods: A total of thirty-five patients diagnosed with mild carpal tunnel syndrome and treated with splint plus exercise therapy; hand resting splint all day for 3 weeks and then only at nights along with nerve gliding exercises in 10 repetitions 3 times a day. The median nerve was evaluated clinically prior to the treatment and at week 6 of therapy using physical examination, electrodiagnostic neurophysiology tests and radiological imaging; Boston Scores, electromyogram, ultrasonography and sonoelastography. Results: Following the 6-week treatment protocol on 35 subjects with mild carpal tunnel syndrome, sonoelastography showed significantly softer median nerve, while the traditional parameters based on Boston Scores and cross-sectional area based on ultrasonography remained nearly unresponsive. Such early indication of biomechanical changes in the nerve may be of clinical importance if it can offer a prognostic value of the applied treatment, while tissue softening suggests the alleviation of nerve compression. Conclusions: Sonoelasticity of the median nerve can serve as a reliable marker for assessing therapeutic changes in median nerve stiffness and potentially the outcome early on in mild carpal tunnel syndrome.Aim of the study: To evaluate the sonoelastic response of the median nerve in patients with carpal tunnel syndrome following conservative rehabilitation with splint plus exercise regimens. Materials and methods: A total of thirty-five patients diagnosed with mild carpal tunnel syndrome and treated with splint plus exercise therapy; hand resting splint all day for 3 weeks and then only at nights along with nerve gliding exercises in 10 repetitions 3 times a day. The median nerve was evaluated clinically prior to the treatment and at week 6 of therapy using physical examination, electrodiagnostic neurophysiology tests and radiological imaging; Boston Scores, electromyogram, ultrasonography and sonoelastography. Results: Following the 6-week treatment protocol on 35 subjects with mild carpal tunnel syndrome, sonoelastography showed significantly softer median nerve, while the traditional parameters based on Boston Scores and cross-sectional area based on ultrasonography remained nearly unresponsive. Such early indication of biomechanical changes in the nerve may be of clinical importance if it can offer a prognostic value of the applied treatment, while tissue softening suggests the alleviation of nerve compression. Conclusions: Sonoelasticity of the median nerve can serve as a reliable marker for assessing therapeutic changes in median nerve stiffness and potentially the outcome early on in mild carpal tunnel syndrome.

Role of intermittent pneumatic compression in the treatment of breast cancer-related lymphoedema: a randomized controlled trial.

OBJECTIVE: To evaluate the role of intermittent pneumatic compression in the treatment of breast cancer-related lymphoedema. DESIGN: Randomized controlled trial. SETTING: Physical medicine and rehabilitation clinic at a university hospital. SUBJECTS: Seventy-six patients with lymphoedema. INTERVENTIONS: Patients were allocated into Group 1 (complex decongestive treatment, n = 38) and Group 2 (complex decongestive treatment + intermittent pneumatic compression, n = 38). The complex decongestive treatment involved skin care, manual lymphatic drainage, compression bandaging, and exercise for 20 sessions. Group 2 additionally received intermittent pneumatic compression. MAIN MEASURES: Quantitative outcomes consisted of volumetric measures prior to and after the treatment. Clinical assessments included severity of pain, heaviness and tightness, disability, grip strength, and depression. RESULTS: Lymphoedema was similar at baseline, but treatments significantly reduced the excess volume (from 373 mL to 203 mL in Group 1 and 379.5 mL to 189.5 mL in Group 2). Percentage excess volumes (PEVs) decreased in both groups. The percentage reduction of excess volume was better in Group 2 than Group 1, but the intergroup difference was not significant. The clinical scores reflected improvements, but the heaviness and tightness read significantly lower in Group 2 than Group 1. CONCLUSION: Intermittent pneumatic compression seems to add no benefit when combined with complex decongestive treatment of lymphoedema, but, may be functional in reducing the sensations of heaviness and tightness for the patients with pitting oedema.

Effects of gadolinium and gadolinium chelates on intracellular calcium signaling in sensory neurons.

Magnetic resonance imaging (MRI) employs gadolinium chelates as contrast agents to provide signal enhancement in radiological images. However, the instability of the chelates presents a challenge as the released gadolinium ion (Gd3+) from the chelates becomes toxic to the surrounding biological tissue. Chelates such as gadodiamide, gadoterate meglumine, gadobutrol and gadobenate dimeglumine are common contrast agents used in clinics. The release of Gd3+ from these agents have been reported previously using experimental setups involving water, but this study evaluates the release in cell culture of dorsal root ganglion (DRG) neurons as this model system is relevant to neuronal toxicity induced by these agents. DRG neurons were grown in primary culture following enzymatic and mechanical dissociation of ganglia from a 2-day-old neonatal Wistar rat. Using Fura-2 based calcium imaging, the effects of gadolinium chelates on free intracellular Ca2+ transport was assessed. The findings indicated that the contrast agent gadoterate meglumine exhibited the best performance in complex stability, independent of its concentration, and thus it must be taken into consideration in standard MRI exams and neuroimaging. The free Gd3+ released from the other agents is also of great concern as it may impact the neurophysiology of the neuronal cells in general, even in normal patients without nephrogenic systemic fibrosis.

A Custom-made Pupillometer System for Characterizing Pupillary Light Response.

OBJECTIVES: This paper presents the design and construction of a viable pupillometer system and demonstrates its merits with extensive validation tests. MATERIALS AND METHODS: A web camera was modified by removing its infrared filter and mounted on a chin rest. Light emitting diodes (LEDs) operating at infrared and visible spectra were integrated to provide background and light stimulus, respectively. The LEDs were controlled by a microprocessor board. Stimulation was presented using a periodic paradigm with variable period and duty cycle. Videos of both pupils were recorded at 30 frames/second and processed offline using software developed in-house. The overall system was validated with data gathered from individuals with healthy vision under different stimulation paradigms. Temporal variations in pupil size were determined and analyzed statistically. RESULTS: The analysis revealed that the pupil sizes were accurately measured from the video frames provided that reflections from both infrared and visible lights remain outside the pupil. The system achieved moderate to excellent repeatability scores (87.8 and 86.8% for short 1 second and long 2 second pulses, respectively), which demonstrated its effectiveness and confirmed that it can be used reliably as a pupillometer. CONCLUSION: The proposed pupillometer system produces useful, quantitative data characterizing pupillary light response. However, further development and implementation are needed to potentially turn it into a low-cost alternative for other studies involving the autonomic nervous system, cognitive function, drug metabolism, pain response, psychology, fatigue, and sleep disorders.

Hepatoprotectivity of Panduratin A against liver damage: In vivo demonstration with a rat model of cirrhosis induced by thioacetamide.

This experiment evaluated Panduratin A (PA), a chalcone isolated from Boesenbergia rotunda rhizomes, for its hepatoprotectivity. Rats were subjected to liver damage induced by intra-peritoneal injection of thioacetamide (TAA). PA was tested first for its acute toxicity and then administered by oral gavage at doses 5, 10, and 50 mg/kg to rats. At the end of the 8th week, livers from all rats were excised and evaluated ex vivo. Measurements included alkaline phosphatase (AP), alanine transaminase (ALT), aspartate transaminase (AST) and gamma-glutamyl transferase (GGT), serum platelet-derived growth factor (PDGF) and transforming growth factor (TGF-ß1), and hepatic metalloproteinase enzyme (MMP-2) and its inhibitor extracellular matrix protein (TIMP-1). Oxidative stress was measured by liver malondialdehyde (MDA) and nitrotyrosine levels, urinary 8-hydroxy 2- deoxyguanosine (8-OH-dG), and hepatic antioxidant enzyme activities. The immunohistochemistry of TGF-ß1 was additionally performed. PA revealed safe dose of 250 mg/kg on experimental rats and positive effect on the liver. The results suggested reduced hepatic stellate cells (HSCs) activity as verified from the attenuation of serum PDGF and TGF-ß1, hepatic MMP-2 and TIMP-1, and oxidative stress. The extensive data altogether conclude that PA treatment could protect the liver from the progression of cirrhosis through a possible mechanism inhibiting HSCs activity.

Dynamics of HCV epidemiology in Aydin province of Turkey and the associated factors.

This paper gives an update on the local distributions of HCV genotypes in Aydin province of Turkey, provides a comparison with the previous records, and discusses the potential causal reasons shaping the evolving genotype profiles. Patient files from 2011 to 2016 were retrospectively analyzed, and newly detected cases were documented. Out of 286 patients, male and female ratios were determined to remain nearly the same (~50%). Genotype 1 was still the most common (90.2%), followed by genotype 3 (5.9%), genotype 2 (2.1%), and genotype 4 (1.4%) in frequency. There were international patients (4.50%). One patient had genotyped 2+3 together. Genotypes 4 and 2+3 were detected for the first time, and the patients with genotype 4 were interestingly all male and also domestic individuals. However, these patients traveled or lived abroad in the past due to occupational reasons, thereby likely acquired the infection while abroad. HCV surveillance system is currently inadequate and some infected patients may go undetected in the province. Remapping the regional distribution of HCV genotypes from time-to-time is required for identifying the local dynamics and causes leading to it. This process enhances the clinical preparation and readiness for the better management of the disease.

Response of Arterial Stiffness Four Weeks After Terminating Short-term Aerobic Exercise Training in a Sedentary Lifestyle.

OBJECTIVES: The purpose of this study was to investigate the response of arterial stiffness in individuals with a sedentary lifestyle at 4 weeks after terminating a 2-week aerobic exercise session. METHODS: Arterial stiffness was evaluated in 38 participants before starting and after completing a prescribed aerobic exercise program and also at 4 weeks after returning back to their sedentary lifestyle. Parameters regarding arterial compliance, distensibility, wall stress, and the elastic modulus were estimated from the information gained from sonography on the dimensions of carotid and femoral arteries and a sphygmomanometer on the pulse pressure. RESULTS: Primary outcomes included whether short-term aerobic exercise reduced the heart rate, arterial pressure, and intima-media thickness and improved vascular biomechanics in physically inactive but otherwise healthy individuals. The benefits gained in arterial compliance and distensibility deteriorated with termination of exercise, but diastolic wall stress and the elastic modulus improved further. CONCLUSIONS: In individuals with sedentary lifestyles, short-term aerobic exercise has strong four-week residual benefits on diastolic wall stress and the elastic modulus, but the effects appear to be negligible on arterial stiffness and distensibility.

Assessment of infarct-specific cardiac motion dysfunction using modeling and multimodal magnetic resonance merging.

PURPOSE: To propose a cardiac motion tracking model that evaluates wall motion abnormality in postmyocardial infarction patients. Correlation between the motion parameter of the model and left ventricle (LV) function was also determined. MATERIALS AND METHODS: Twelve male patients with post-ST elevation myocardial infarction (post-STEMI) and 10 healthy controls of the same gender were recruited to undergo cardiac magnetic resonance imaging (MRI) using a 1.5T scanner. Using an infarct-specific LV division approach, the late gadolinium enhancement (LGE) MRI images were used to divide the LV on the tagged MRI images into infarct, adjacent, and remote sectors. Motion tracking was performed using the infarct-specific two-parameter empirical deformable model (TPEDM). The match quality was defined as the position error computed using root-mean-square (RMS) distance between the estimated and expert-verified tag intersections. The position errors were compared with the ones from our previously published fixed-sector TPEDM. Cine MRI images were used to calculate regional ejection fraction (REF). Correlation between the end-systolic contraction parameter (αES ) with REF was determined. RESULTS: The position errors in the proposed model were significantly lower than the fixed-sector model (P < 0.01). The median position errors were 0.82 mm versus 1.23 mm. The αES correlates significantly with REF (r = 0.91, P < 0.01). CONCLUSION: The infarct-specific TPEDM combines the morphological and functional information from LGE and tagged MRI images. It was shown to outperform the fixed-sector model in assessing regional LV dysfunction. The significant correlation between αES and REF added prognostic value because it indicated an impairment of cardiac function with the increase of infarct transmurality. LEVEL OF EVIDENCE: 3 J. Magn. Reson. Imaging 2017;45:525-534.

Carotid Arterial Flow in Pseudoexfoliation Glaucoma and its Role in Diagnosing the Disease.

OBJECTIVE OF THE STUDY: The objective of the study was to investigate the change in carotid arterial flow in pseudoexfoliation glaucoma (XFG) for determining its diagnostic value. MATERIALS AND METHODS: Patients with XFG (N=30) and control subjects (N=22) were recruited. Common carotid artery (CCA) and internal carotid artery of each participant were examined using color Doppler and B-mode ultrasonography. Resistivity index (RI), as a flow parameter of interest, was measured and statistically compared between the 2 groups. Receiver operating characteristic was also produced to assess its diagnostic value. RESULTS: The measured RI values from the controls were within the expected range. Among CCA and internal carotid artery, only RI of CCA exhibited statistically significant changes in XFG (0.75±0.04 vs. 0.70±0.03 cm/s). Threshold value of RI=0.72 yielded 90% sensitivity and 73% specificity in distinguishing the cases of XFG from the controls. CONCLUSIONS: Flow dynamics of carotid arterial system exhibits different characteristics in individuals with XFG than controls. Such differences may serve as a basis for developing potentially new diagnostic biomarkers of XFG. Further studies are justified for examining the carotid flow in pseudoexfoliation syndrome and compare it against XFG for determining its power in differential diagnosis.

Observer performance in characterization of carotid plaque texture and surface characteristics with 3D versus 2D ultrasound.

OBJECTIVE: To determine the reproducibility of three-dimensional (3D) ultrasound (US) over two-dimensional (2D) US in characterizing atherosclerotic carotid plaques using inter- and intra-observer agreement metrics. METHODS: A Total of 51 patients with 105 carotid artery plaques were screened using 3D and 2D US probes attached to the same US scanner. Two independent observers characterized the plaques based on the morphological features namely echotexture, echogenicity and surface characteristics. The scores assigned to each morphological feature were used to determine intra- and inter-observer performance. The level of agreement was measured using Kappa coefficient. RESULTS: The first observer with 2D US showed fair (k=0.4-0.59) and very strong (k>0.8) with 3D US intra-observer agreements using three morphological features. The second observer indicated moderate strong (k=0.6-0.79) with 2D US and very strong with 3D US (k>0.8) intra-observer performances. Moderate strong (k=0.6-0.79) and very strong (k>0.8) inter-observer agreements were reported with 2D US and 3D US respectively. The results with 2D and 3D US were correlated 62% using only echotexture and 56% using surface morphology coupled with echogenicity. 3D US gave a lower score than 2D 71% of the time (p=0.005) in disagreement cases. CONCLUSION: High reproducibility in carotid plaque characterization was obtained using 3D US rather than 2D US. Hence, it can be a preferred imaging modality in routine or follow up plaque screening of patients with carotid artery disease.

Characterization of tympanic cavity volume in newborns using computerized tomography scanning / Caracterización del volumen de la cavidad timpánica en recién nacidos usando tomografía computadorizada

This study reports tympanic cavity (TC) volume in newborns, which was missing in the literature. Ex vivo histology and computerized tomography (CT) scans were performed on temporal bone and data were analyzed in part using software developed in house. CT images with a slice thickness of 0.5 mm were obtained from 5 newborn cadavers and analyzed independently by two expert researchers. The border of the TC was delineated manually and measurement of area of interest was calculated on masked images. Then, the area measurements from all sections were added to estimate the total volume. The agreements between the histological and CT findings were then compared for accuracy, repeatability and reliability. The Dice and Jaccard similarity coefficient measures were used as a statistical validation metric to evaluate the assessor's performance in manual volume segmentation. Good assessor agreement was observed with average Dice values above 0.8 indicating that consistent and reliable volume measurements were feasible. The proposed protocol was shown to be accurate in calculating the TC volume, and thus can be used for computer-assisted presurgical planning or for diagnosing structural alterations in TC.

El objetivo fue determinar el volumen de la cavidad timpánica (CT) en recién nacidos, información no encontrada en la literatura. Se realizaron escaners a través de tomografia computadorizada (TC) y estudios histológicos en el hueso temporal; los datos se analizaron utilizando un software desarrollado en nuestra institución. Se obtuvieron imágenes de secciones de TC, de 0,5 mm de grosor, a partir de 5 cadáveres de recién nacidos, los que fueron analizados de forma independiente por dos investigadores expertos. El margen de los cortes de TC fue delineado manualmente y la medición del área de interés se estimó sobre imágenes ocultas. Después, se añadieron las mediciones de área de todas las secciones para estimar el volumen total. Las concordancias entre el estudio histológico y los hallazgos de la TC se compararon en cuanto a precisión, repetibilidad y confiabilidad. Se utilizaron las medidas de coeficiente de similitud de Jaccard y Dice como métrica de validación estadística para evaluar el desempeño del asesor en la medición manual del volumen. Se observó una buena correlación del evaluador con los valores medios de Dice, por encima de 0,8 indicando que es factible obtener mediciones coherentes y confiables de volumen. El protocolo propuesto ha demostrado ser preciso para calcular el volumen de la CT, y por lo tanto se puede utilizar para la planificación prequirúrgica asistida o para el diagnóstico de alteraciones estructurales en la CT.

S100A1 as a Potential Diagnostic Biomarker for Assessing Cardiotoxicity and Implications for the Chemotherapy of Certain Cancers.

This study examined the value of blood marker S100A1 in detecting cardiotoxicity induced by chemotherapy agents; trastuzumab and lapatinib, in normal rat heart. The rats were divided into three groups: control (n = 8, no treatment), T (n = 8, one time ip treatment with 10 mg/kg trastuzumab) and L (n = 8, oral treatment with 100 mg/kg/day lapatinib for 7 days). The activities of oxidative stress parameters Malondialdehyde (MDA), Superoxide dismutase (SOD), Catalase (CAT) and Glutathione (GSH) were measured from the extracted cardiac tissues. The levels of troponinI and S100A1 expressions were measured from blood samples. All biomarkers responded to the treatments as they exhibited alterations from their normative values, validating the chemically induced cardiotoxicity. S100A1 expression attenuated significantly (75%), which made the sensitive detection of cardiotoxicity feasible. Assessment of cardiotoxicity with S100A1 may be a valuable alternative in clinical oncology of cancers in some organs such as breast and prostate, as they do not overexpress it to compete against.

In vivo nephroprotective efficacy of propolis against contrast-induced nephropathy.

PURPOSE: Contrast agents administered in diagnostic imaging or interventional procedures of clinical radiology may cause contrast-induced nephropathy (CIN). Preventive measures against CIN involve pharmaceutical pretreatments, such as N-acetylcystein (NAC) or calpain, but alternative medicines can also be helpful. This study aims to assess the prospects of a natural compound, propolis, as a potential nephroprotector against a specific contrast agent, diatrizoate. METHODS: In vivo experiments were performed on 35 male rats in five groups: control, diatrizoate alone, and pretreatments with propolis, NAC, or calpain one hour before diatrizoate administration. Three days later, blood and renal tissue samples were collected and quantitatively processed for determining induced changes in critical biomarkers malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT), as well as serum creatinine and plasma urea. RESULTS: Diatrizoate increased creatinine (113%), urea (400%), and MDA (162%) levels and decreased GSH (-71%), SOD (-69%), GSH-Px (-77%), and CAT (-73%) levels. Evaluating the response of each pretreatment provided sufficient evidence that propolis was as effective as either NAC or calpain, but consistently more prominent in restoring the MDA, GSH, SOD, and GSH-Px levels close to their normal range. This outcome demonstrated the nephroprotective effect of propolis against CIN. CONCLUSION: Propolis protects renal tissue against toxicity, free radicals, and other adverse effects induced by diatrizoate. This function is most likely exerted through the antioxidant and antitoxic activities of propolis.

Regional assessment of LV wall in infarcted heart using tagged MRI and cardiac modelling.

A segmental two-parameter empirical deformable model is proposed for evaluating regional motion abnormality of the left ventricle. Short-axis tagged MRI scans were acquired from 10 healthy subjects and 10 postinfarct patients. Two motion parameters, contraction and rotation, were quantified for each cardiac segment by fitting the proposed model using a non-rigid registration algorithm. The accuracy in motion estimation was compared to a global model approach. Motion parameters extracted from patients were correlated to infarct transmurality assessed with delayed-contrast-enhanced MRI. The proposed segmental model allows markedly improved accuracy in regional motion analysis as compared to the global model for both subject groups (1.22-1.40 mm versus 2.31-2.55 mm error). By end-systole, all healthy segments experienced radial displacement by ~25-35% of the epicardial radius, whereas the 3 short-axis planes rotated differently (basal: 3.3°; mid: -1° and apical: -4.6°) to create a twisting motion. While systolic contraction showed clear correspondence to infarct transmurality, rotation was nonspecific to either infarct location or transmurality but could indicate the presence of functional abnormality. Regional contraction and rotation derived using this model could potentially aid in the assessment of severity of regional dysfunction of infarcted myocardium.

Susceptibility-Based Differentiation of Intracranial Calcification and Hemorrhage in Pediatric Patients.

Differential diagnosis of intracranial hemorrhage versus calcification on conventional magnetic resonance images (MRIs) is often challenging. Although computed tomography (CT) confirms calcification, phase information obtained during susceptibility-weighted imaging can be useful in distinguishing between 2 pathologies. Fourteen patients previously diagnosed to have hemorrhage or calcification with imaging were included in the study retrospectively. Phase shift values of hemorrhage and calcification were compared by using Student t test. The pathologies identified were tuberous sclerosis, Sturge-Weber syndrome, craniopharyngioma, congenital cytomegalovirus, subependymal hemorrhages, and hemorrhagic microembolic infarction. Calcifications appeared hypointense whereas hemorrhages were hyperintense on phase maps (left-handed magnetic resonance system). Statistical comparison of phase shift values yielded significant difference between hemorrhage versus calcification (P < .01). Phase maps were found to offer valuable data to differentiate 2 pathologies when used complementary to conventional magnetic resonance images. Considering the relatively higher risks of radiation exposure in children, susceptibility-weighted imaging with phase maps may help to waive radiation exposure from CT.

A magnetic resonance imaging study on the articulatory and acoustic speech parameters of Malay vowels.

The phonetic properties of six Malay vowels are investigated using magnetic resonance imaging (MRI) to visualize the vocal tract in order to obtain dynamic articulatory parameters during speech production. To resolve image blurring due to the tongue movement during the scanning process, a method based on active contour extraction is used to track tongue contours. The proposed method efficiently tracks tongue contours despite the partial blurring of MRI images. Consequently, the articulatory parameters that are effectively measured as tongue movement is observed, and the specific shape of the tongue and its position for all six uttered Malay vowels are determined.Speech rehabilitation procedure demands some kind of visual perceivable prototype of speech articulation. To investigate the validity of the measured articulatory parameters based on acoustic theory of speech production, an acoustic analysis based on the uttered vowels by subjects has been performed. As the acoustic speech and articulatory parameters of uttered speech were examined, a correlation between formant frequencies and articulatory parameters was observed. The experiments reported a positive correlation between the constriction location of the tongue body and the first formant frequency, as well as a negative correlation between the constriction location of the tongue tip and the second formant frequency. The results demonstrate that the proposed method is an effective tool for the dynamic study of speech production.

Protective activity of Panduratin A against thioacetamide-induced oxidative damage: demonstration with in vitro experiments using WRL-68 liver cell line.

BACKGROUND: Chalcone Panduratin A (PA) has been known for its antioxidant property, but its merits against oxidative damage in liver cells has yet to be investigated. Hence, the paper aimed at accomplishing this task with normal embryonic cell line WRL-68. METHODS: PA was isolated from Boesenbergia rotunda rhizomes and its 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and ferric reducing power (FRAP) activities were measured in comparison with that of the standard reference drug Silymarin (SI). Oxidative damage was induced by treating the cells with 0.04 g/ml of toxic thioacetamide for 60 minutes followed by treatment with 1, 10 and 100 µg/ml concentrations of either PA or SI. The severities of oxidative stress in the control and experimental groups of cells were measured by Malondialdehyde (MDA) levels, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities. RESULTS: PA exhibited an acceptable DPPH scavenging and FRAP activities close to that of Silymarin. Treating the injured cells with PA significantly reduced the MDA level and increased the cell viability, comparable to SI. The activities of SOD, CAT and GPx were significantly elevated in the PA-treated cells in a dose dependent manner and again similar to SI. CONCLUSION: Collectively, data suggested that PA has capacity to protect normal liver cells from oxidative damage, most likely via its antioxidant scavenging ability.

Iron accumulation in multiple sclerosis: an early pathogenic event.

Iron has been shown to accumulate in deep gray matter structures in many forms of multiple sclerosis (MS), but detecting its presence early in the disease course (e.g., clinically isolated syndrome [CIS]) has been less clear. Here, we review a recent study where MRI scanning at 7 T together with susceptibility mapping was performed to assess iron deposition in CIS and control subjects. Susceptibility indicative of iron deposition was found to be increased in the globus pallidus, caudate, putamen and pulvinar of CIS patients compared with controls. The findings suggest that iron deposition is a pathological change that occurs early in the development of MS. Identifying the mechanisms of iron accumulation and determining whether iron promotes pathogenesis in MS are important areas of future research.