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1.
Br J Dermatol ; 176(2): 395-402, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27452897

ABSTRACT

BACKGROUND: Antimelanoma differentiation-associated protein (anti-MDA)5 antibodies are associated with rapidly progressive interstitial lung disease (RP-ILD) in patients with clinically amyopathic dermatomyositis (CADM) or dermatomyositis (DM). OBJECTIVES: We aimed to evaluate the relevance of monitoring anti-MDA5 antibody levels for the management of RP-ILD in patients with CADM or DM. METHODS: Twelve patients with CADM (n = 10) or DM (n = 2) accompanied by RP-ILD were included. Baseline characteristics and outcomes were recorded. Serial measurements of anti-MDA5 antibody levels were measured. All patients were treated with corticosteroids, tacrolimus and intravenous cyclophosphamide. RESULTS: All patients achieved RP-ILD remission after combined immunosuppressive therapy for a mean of 6Ā·8 months, with significant decreases noted in the mean anti-MDA5 antibody levels at remission. Six (50%) patients became anti-MDA5 antibody negative after therapy. After a mean follow-up of 31 months, RP-ILD relapse was observed in four (33%) patients in both the anti-MDA5 antibody sustained positive group and the negative conversion group. However, relapsed patients in the sustained positive group relapsed earlier than those in the negative conversion group. Thus, a decrease in anti-MDA5 antibody levels during remission was associated with longer remission. Relapses were associated with a reincrease of anti-MDA5 antibody levels in four of four (100%) patients. In contrast, none of the patients without reincrease in anti-MDA5 antibody exhibited symptoms of relapse during follow-up. Therefore, reincrease in anti-MDA5 antibody levels was associated with relapse. CONCLUSIONS: The anti-MDA5 antibody level is a novel parameter for monitoring and a good predictor of RP-ILD relapse in patients with CADM or DM.


Subject(s)
Dermatomyositis/immunology , Lung Diseases, Interstitial/immunology , Adrenal Cortex Hormones/therapeutic use , Autoantibodies/metabolism , Cyclophosphamide/therapeutic use , Dermatologic Agents/therapeutic use , Dermatomyositis/drug therapy , Drug Therapy, Combination , Female , Humans , Immunosuppressive Agents/therapeutic use , Interferon-Induced Helicase, IFIH1/immunology , Lung Diseases, Interstitial/drug therapy , Male , Middle Aged , Recurrence , Treatment Outcome
2.
J Stroke Cerebrovasc Dis ; 26(5): 1144-1153, 2017 May.
Article in English | MEDLINE | ID: mdl-28256416

ABSTRACT

BACKGROUND: Vertigo or dizziness is a common occurrence, but it remains a challenging symptom when encountered in the emergency department (ED). A diagnostic score for stroke with high accuracy is therefore required. METHODS: A single-center observational study (498 patients) was conducted. The predictor variables were derived from a multivariate logistic regression analysis with Akaike information criterion. The outcome was the occurrence of stroke. We evaluated the utility of a new diagnostic score (TriAGe+) and compared it with the ABCD2 score. RESULTS: The cohorts included 498 patients (147 with stroke [29.4%]). Eight variables were included: triggers, atrial fibrillation, male gender, blood pressure ≥140/90 mm Hg, brainstem or cerebellar dysfunction, focal weakness or speech impairment, dizziness, and no history of vertigo or dizziness or labyrinth or vestibular disease. We derived the TriAGe+ score from these variables. In the cohort, the prevalence of stroke increased significantly using the diagnostic score: 5.9% for a score of 0-4; 9.1% for 5-7; 24.7% for 8-9; and 57.3% for 10-17. At a cutoff value of 10 points, the sensitivity of the score was 77.5%, the specificity was 72.1%, and the positive likelihood ratio was 3.2. When the cutoff was defined as 5 points, the score obtained a high sensitivity (96.6%) with a good negative likelihood ratio (.15). The new score outperformed the ABCD2 score for the occurrence of stroke (C statistic, .818 versus .726; P < .001). CONCLUSIONS: The TriAGe+ score can identify the occurrence of stroke in patients with vertigo or dizziness presenting to the ED.


Subject(s)
Decision Support Techniques , Dizziness/epidemiology , Emergency Service, Hospital , Stroke/diagnosis , Stroke/epidemiology , Triage/methods , Vertigo/epidemiology , Aged , Aged, 80 and over , Area Under Curve , Female , Humans , Japan/epidemiology , Male , Middle Aged , Observer Variation , Predictive Value of Tests , Prevalence , Prognosis , ROC Curve , Reproducibility of Results , Risk Assessment , Risk Factors
3.
Spinal Cord ; 54(7): 521-9, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26481711

ABSTRACT

STUDY DESIGN: Experimental training model of rats with spinal cord injury (SCI). SETTING: Osaka, JapanObjective:To investigate the effect of forced treadmill training by plantar placement (PP), as compared with dorsal placement (DP), of the dorsal paws on the locomotor behaviors of spinal cord-injured rats. METHODS: The spinal cord was contusion-injured at the thoracic level. Rats were divided into three groups: forced training involving stepping by PP and DP and non-forced training/assistance (nT). Training began 1 week after injury and was conducted for 4 weeks. Locomotor behaviors were estimated using Basso-Beattie-Bresnahan (BBB) scores, dorsiflexion of the hind paws and footprints of the hind paws. Histological and immunohistochemical examinations of the spinal cord lesions were conducted after 4 weeks of training. RESULTS: The values, respectively, of PP, DP and nT groups at 4 weeks of training were as follows: BBB scores were 15.6Ā±0.8, 7.7Ā±1.3 and 10.3Ā±0.4. The paw dorsiflexion angles were 34.1Ā±5.2, 16.4Ā±2.4 and 23.6Ā±3.0 degrees, respectively. The stride angles were 5.1Ā±0.9, 13.7Ā±4.9 and 17.8Ā±4.0 degrees for the left paws. Cavity volumes were 10.3Ā±2.1, 31.0Ā±2.0 and 28.2Ā±4.9%. In addition to cavities, there were astrocyte-devoid areas containing some loose tissues, through which many axons extended longitudinally. CONCLUSIONS: The BBB score, dorsiflexion angle and stride angle were consistently improved in the PP group. Cavity formation was more reduced, and many axons extended through coarse tissues formed in astrocyte-devoid areas at the lesion in the PP group. Forced training by PP of the hind paws promoted the behavioral and histological improvement of rats with SCI.


Subject(s)
Exercise Test/methods , Exercise Therapy/methods , Locomotion/physiology , Lower Extremity/physiopathology , Recovery of Function/physiology , Spinal Cord Injuries/rehabilitation , Animals , Axons/metabolism , Axons/pathology , Disease Models, Animal , Female , Glial Fibrillary Acidic Protein/metabolism , Psychomotor Performance , Rats , Rats, Sprague-Dawley , Spinal Cord/pathology , Spinal Cord Injuries/pathology
4.
J Physiol ; 592(17): 3859-80, 2014 Sep 01.
Article in English | MEDLINE | ID: mdl-25015920

ABSTRACT

Controlled mechanical ventilation (CMV) plays a key role in triggering the impaired diaphragm muscle function and the concomitant delayed weaning from the respirator in critically ill intensive care unit (ICU) patients. To date, experimental and clinical studies have primarily focused on early effects on the diaphragm by CMV, or at specific time points. To improve our understanding of the mechanisms underlying the impaired diaphragm muscle function in response to mechanical ventilation, we have performed time-resolved analyses between 6 h and 14 days using an experimental rat ICU model allowing detailed studies of the diaphragm in response to long-term CMV. A rapid and early decline in maximum muscle fibre force and preceding muscle fibre atrophy was observed in the diaphragm in response to CMV, resulting in an 85% reduction in residual diaphragm fibre function after 9-14 days of CMV. A modest loss of contractile proteins was observed and linked to an early activation of the ubiquitin proteasome pathway, myosin:actin ratios were not affected and the transcriptional regulation of myosin isoforms did not show any dramatic changes during the observation period. Furthermore, small angle X-ray diffraction analyses demonstrate that myosin can bind to actin in an ATP-dependent manner even after 9-14 days of exposure to CMV. Thus, quantitative changes in muscle fibre size and contractile proteins are not the dominating factors underlying the dramatic decline in diaphragm muscle function in response to CMV, in contrast to earlier observations in limb muscles. The observed early loss of subsarcolemmal neuronal nitric oxide synthase activity, onset of oxidative stress, intracellular lipid accumulation and post-translational protein modifications strongly argue for significant qualitative changes in contractile proteins causing the severely impaired residual function in diaphragm fibres after long-term mechanical ventilation. For the first time, the present study demonstrates novel changes in the diaphragm structure/function and underlying mechanisms at the gene, protein and cellular levels in response to CMV at a high temporal resolution ranging from 6 h to 14 days.


Subject(s)
Diaphragm/physiopathology , Muscle Contraction , Muscle Fibers, Skeletal/metabolism , Pulmonary Ventilation , Ventilators, Mechanical/adverse effects , Actins/genetics , Actins/metabolism , Adenosine Triphosphate/metabolism , Animals , Diaphragm/cytology , Diaphragm/metabolism , Female , Lipid Metabolism , Muscle Fibers, Skeletal/physiology , Muscle Strength , Myosins/genetics , Myosins/metabolism , Nitric Oxide Synthase Type I/genetics , Nitric Oxide Synthase Type I/metabolism , Oxidative Stress , Proteasome Endopeptidase Complex/metabolism , Rats , Rats, Sprague-Dawley , Time Factors
5.
Br J Cancer ; 111(8): 1614-24, 2014 Oct 14.
Article in English | MEDLINE | ID: mdl-25117812

ABSTRACT

BACKGROUND: Recent studies have demonstrated that microRNAs are stably detectable in plasma/serum because of their binding to specific proteins or being packaged in secretory particles. This study was designed to detect novel microRNAs in plasma for cancer detection and monitoring using microRNA array-based approaches in oesophageal squamous cell carcinoma (ESCC) patients. METHODS: Through the integration of two Toray 3D-Gene microRNA array-based approaches to compare plasma microRNA levels between ESCC patients and healthy volunteers and between preoperative and postoperative ESCC patients, we identified a novel plasma biomarker in ESCC. RESULTS: (1) Eight upregulated and common microRNAs (miR-15b, 16, 17, 25, 19b, 20a, 20b, and 106a) were selected using two high-resolution microRNA array approaches. (2) Test-scale analyses by quantitative RT-PCR validated a significant higher levels of plasma miR-19b (P=0.0020) and miR-25 (P=0.0030) in ESCC patients than controls. However, a significant correlation was observed between plasma miR-19b levels and concentrations of red blood cells (P=0.0073) and haemoglobin (P=0.0072). (3) miR-25 expression was found to be significantly higher in ESCC tissues (P=0.0157) and ESCC cell lines (P=0.0093) than in normal tissues and fibroblasts. (4) In a large-scale validation analysis, plasma miR-25 levels were significantly higher in 105 preoperative (P<0.0001) ESCC patients who underwent curative oesophagectomy and 20 superficial ESCC patients who underwent endoscopic resection (P<0.0001) than in 50 healthy volunteers. (5) Plasma miR-25 levels were significantly reduced in postoperative samples than in preoperative samples (P<0.0005) and were significantly increased during ESCC recurrences (P=0.0145). CONCLUSIONS: Plasma miR-25 might be a clinically useful biomarker for cancer detection and the monitoring of tumour dynamics in ESCC patients.


Subject(s)
Biomarkers, Tumor/blood , Carcinoma, Squamous Cell/diagnosis , Esophageal Neoplasms/diagnosis , MicroRNAs/blood , Aged , Carcinoma, Squamous Cell/blood , Esophageal Neoplasms/blood , Female , Humans , Male , Middle Aged , Oligonucleotide Array Sequence Analysis
6.
J Synchrotron Radiat ; 19(Pt 3): 332-9, 2012 May.
Article in English | MEDLINE | ID: mdl-22514166

ABSTRACT

Synchrotron-generated microbeam radiotherapy holds great promise for future treatment, but the high dose gradients present conventional dosimetry with a challenge. Measuring the important peak-to-valley dose ratio (PVDR) of a microbeam-collimated synchrotron source requires both a dosimeter and an analysis method capable of exceptional spatial resolution. The PVDR is of great interest since it is the limiting factor for potential application of the microbeam radiation therapy technique clinically for its tissue-sparing properties (i.e. the valley dose should be below the tolerance of normal tissue). In this work a new method of measuring the dose response of PRESAGE dosimeters is introduced using the fluorescence from a 638Ć¢Ā€Ā…nm laser on a confocal laser-scanning microscope. This fluorescent microscopy method produces dosimetry data at a pixel size as low as 78Ć¢Ā€Ā…nm, giving a much better spatial resolution than optical computed tomography, which is normally used for scanning PRESAGE dosimeters. Using this technique the PVDR of the BL28B2 microbeam at the SPring-8 synchrotron in Japan is estimated to be approximately 52:1 at a depth of 2.5Ć¢Ā€Ā…mm. The PVDR was also estimated with EBT2 GAFchromic films as 30.5:1 at the surface in order to compare the PRESAGE fluorescent results with a more established dosimetry system. This estimation is in good agreement with previously measured ratios using other dosimeters and Monte Carlo simulations. This means that it is possible to use PRESAGE dosimeters with confocal microscopy for the determination of PVDR.


Subject(s)
Radiometry/methods , Radiotherapy Dosage , Synchrotrons , Fluorescence , Humans , Neoplasms/radiotherapy , Radiotherapy Planning, Computer-Assisted/methods , Tomography, Optical
7.
Digestion ; 86(2): 161-70, 2012.
Article in English | MEDLINE | ID: mdl-22889937

ABSTRACT

BACKGROUND/AIMS: To evaluate the usefulness of flexible spectral imaging color enhancement with indigo carmine (I-FICE) in early gastric cancer (EGC) demarcation. METHODS: The study participants were 29 patients with differentiated-type EGC. The endoscope was fixed and images of the same area of EGC demarcations in each lesion were obtained using four different methods (WLE, flexible spectral imaging color enhancement (FICE), CE, and I-FICE). FICE mode at R 550 nm (Gain: 2), G 500 nm (Gain: 4), and B 470 nm (Gain: 4) was used. Four endoscopists ranked the images obtained by each method on the basis of the ease of recognition of demarcation using a 4-point system. We calculated the standard deviation of pixel values based on L*, a*, and b* color spaces in the demarcation region (Lab-SD score). RESULTS: The median ranking score for I-FICE images was significantly higher than that obtained from the other methods. Further, the average Lab-SD score was significantly higher for I-FICE images than for images obtained by the other methods. There was a good correlation between the ranking score and Lab-SD score. CONCLUSION: EGC demarcations were most easily recognized both subjectively and objectively using I-FICE image, followed by CE, FICE and WLE images.


Subject(s)
Adenocarcinoma/diagnosis , Gastroscopy/methods , Image Enhancement/methods , Stomach Neoplasms/diagnosis , Adenocarcinoma/pathology , Aged , Coloring Agents , Early Detection of Cancer/methods , Female , Humans , Indigo Carmine , Male , Middle Aged , Stomach Neoplasms/pathology
8.
J Synchrotron Radiat ; 18(Pt 2): 217-23, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21335908

ABSTRACT

X-ray imaging detectors with an identical phosphor and a CCD chip but employing lens- and fiber-coupling between them have been compared. These are designed for X-ray imaging experiments, especially computed tomography, at the medium-length beamline at the SPring-8 synchrotron radiation facility. It was found that the transmittance of light to the CCD is about four times higher in the fiber-coupled detector. The uniformity of response in the lens-coupled detector has a global shading of up to 40%, while pixel-to-pixel variation owing to a chicken-wire pattern was dominant in the fiber-coupled detector. Apart from the higher transmittance, the fiber-coupled detector has a few characteristics that require attention when it is used for computed tomography, which are browning of the fiber, discontinuity in the image, image distortion, and dark spots in the chicken-wire pattern. Thus, it is most suitable for high-speed tomography of samples that tend to deform, for example biological and soft materials.


Subject(s)
Tomography, X-Ray Computed/methods , X-Ray Microtomography/methods , Equipment Design , Lenses , Tomography, X-Ray Computed/instrumentation , X-Ray Microtomography/instrumentation
9.
Cephalalgia ; 30(4): 496-9, 2010 Apr.
Article in English | MEDLINE | ID: mdl-19515123

ABSTRACT

Patients with severe primary headache may benefit from consultation with headache specialists, but doctor attendance rates in Japan are very low. More headache patients might consult headache specialists if these specialists were more widely recognized by the public. To determine what information prompted patients to seek consultation with a headache specialist, we questioned 256 primary headache patients about the source of the helpful information concerning consultation with headache specialists. From 191 patients, a total of 235 responses to the questionnaire were obtained. The most common response was 'websites' (33.2%), followed by 'professionals' (23.8%), 'acquaintances' (20.9%), 'print media' (6.8%) and 'TV/radio' (3.4%). Patients who indicated websites showed the most severe pain and highest impact of headache, and accounted for 52.4% of those with cluster headaches. Development of websites concerning headache specialists would seem likely to increase doctor attendance rates for patients with primary headache.


Subject(s)
Cluster Headache/therapy , Headache Disorders, Primary/therapy , Internet/statistics & numerical data , Patient Acceptance of Health Care/statistics & numerical data , Patient Education as Topic/statistics & numerical data , Referral and Consultation/statistics & numerical data , Adult , Asian People/statistics & numerical data , Cluster Headache/ethnology , Female , Headache Disorders, Primary/ethnology , Humans , Information Dissemination , Japan/epidemiology , Male , Mass Media/statistics & numerical data , Middle Aged , Neurology/statistics & numerical data , Patient Satisfaction , Surveys and Questionnaires , Young Adult
10.
Caries Res ; 44(3): 253-9, 2010.
Article in English | MEDLINE | ID: mdl-20516685

ABSTRACT

Remineralization is the process by which hydroxyapatite (HAp) is restored in enamel subsurface lesions, and transversal microradiography (TMR) has been used to analyze remineralization in terms of the recovery of mineral content. In this study, we directly detected the distribution and orientation of longitudinal HAp crystallite at the remineralized zone in enamel subsurface lesions by using an X-ray microbeam (6-mum diameter) diffraction method. This method was demonstrated and involves the simultaneous detection of wide-angle X-ray diffraction (WAXRD) and small-angle X-ray scattering (SAXS). WAXRD reflects the amount of HAp crystallites, and SAXS reflects that of voids in crystallites. The polished surface of a bovine enamel block was divided into three zones of sound, demineralized, and remineralized zones. Thin sections of approximately 150 mum thickness were then cut perpendicular to the surface, and subjected to WAXRD and SAXS following TMR. The increase in the amount of HAp crystallites and the decrease in voids in the crystallites at the remineralized zone were detected by WAXRD and SAXS, respectively, which was consistent with the result of TMR. This study indicates that both the spatial distribution and orientation of the restored HAp crystals in the remineralization process at the subsurface lesion can be simultaneously analyzed by the X-ray diffraction methods.


Subject(s)
Dental Enamel/chemistry , Durapatite/chemistry , Tooth Remineralization , Animals , Cattle , Crystallization , Crystallography, X-Ray/methods , Dental Enamel/pathology , Microradiography
11.
Radiol Case Rep ; 15(9): 1437-1441, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32642013

ABSTRACT

Malperfusion syndrome is considered one of the most significant adverse events in aortic dissection disease and often requires invasive strategies to improve ischemia. We report the case of a patient who was presented with worsening claudication and leg rest pain due to malperfusion syndrome of type B aortic dissection. We successfully performed endovascular fenestration therapy to relieve the symptom by using a NRG radiofrequency transseptal needle (Baylis Medical, Montreal, Canada). We suggest that this novel method would be available for the patients with malperfusion syndrome of aortic dissection.

12.
J Synchrotron Radiat ; 16(Pt 3): 398-404, 2009 May.
Article in English | MEDLINE | ID: mdl-19395806

ABSTRACT

Early caries lesion is a demineralization process that takes place in the top 0.1 mm layer of tooth enamel. In this study, X-ray microbeam diffraction was used to evaluate the hydroxyapatite crystallites in the subsurface lesion of a bovine enamel section and the results are compared with those obtained by transversal microradiography, a method commonly used for evaluation of tooth mineral. Synchrotron radiation from SPring-8 was used to obtain a microbeam with a diameter of 6 microm. Wide-angle X-ray diffraction reports the amount of hydroxyapatite crystals, and small-angle X-ray scattering reports that of voids in crystallites. All three methods showed a marked decrease in the enamel density in the subsurface region after demineralization. As these diffraction methods provide structural information in the nanometre range, they are useful for investigating the mechanism of the mineral loss in early caries lesion at a nanometre level.


Subject(s)
Dental Enamel/diagnostic imaging , Dental Enamel/ultrastructure , X-Ray Diffraction/methods , Animals , Cattle , In Vitro Techniques , Radiography , Surface Properties
13.
Science ; 207(4428): 307-8, 1980 Jan 18.
Article in English | MEDLINE | ID: mdl-6444254

ABSTRACT

Highly stretched muscles in which thick and thin filaments no longer overlap produce little or no tension on activation. In preparations producing no tension, the 42.9-nanometer myosin layer line shown in x-ray diffraction patterns does not become weaker. This suggests that myosin heads do not move from their resting positions in the absence of actin.


Subject(s)
Muscle Contraction , Myosins/physiology , Actins/physiology , Adenosine Triphosphatases/metabolism , Animals , Anura , Calcium/physiology , Motion , Muscles/ultrastructure
14.
Science ; 197(4304): 685-7, 1977 Aug 12.
Article in English | MEDLINE | ID: mdl-301660

ABSTRACT

The heads of myosin molecules, which move to the vicinity of the thin filaments to react with actin during muscle contraction, return to the thick filaments after contraction. The return occurs in two stages; a rapid return of the majority of the myosin heads is followed by a slow return of the rest.


Subject(s)
Muscle Contraction , Myosins/metabolism , Animals , Anura , In Vitro Techniques , Kinetics , Muscles/ultrastructure , Rana catesbeiana , X-Ray Diffraction
15.
Endoscopy ; 41(9): 758-61, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19746316

ABSTRACT

BACKGROUND AND STUDY AIM: Endoscopic submucosal dissection (ESD) for colorectal tumors is not generally recommended because of the technical difficulties and complications, including perforation. These aspects of ESD are thoroughly analyzed in our retrospective study. PATIENTS AND METHODS: We studied 105 colorectal tumors, from 100 patients, that were treated by ESD at the Kyoto Prefectural University of Medicine or Nara City Hospital between 2005 and 2008. We analyzed tumor size, operation time, rate of en bloc resection, and complications. In addition, we thoroughly investigated the cases of perforation. RESULTS: The average tumor size was 30.4 mm; average operation time, 102 min; and rate of en bloc resection, 88.5 %. Perforation occurred in 10.4 % of the ESD procedures. Of the 11 perforations, 8 were detected during ESD and treated by clip closure during endoscopy, while 3 were evident only on subsequent routine computed tomography (CT); these were also managed conservatively. A case of postoperative hemorrhage was also observed. CONCLUSIONS: ESD effectively achieved a high rate of en bloc resection. However, the perforation rate was substantial; hence, improvement in the ESD method is required. The outcomes of ESD, especially for early colorectal malignancies, need to be assessed further.


Subject(s)
Colonic Neoplasms/surgery , Dissection/methods , Endoscopy, Gastrointestinal/methods , Rectal Neoplasms/surgery , Aged , Aged, 80 and over , Endoscopy, Gastrointestinal/adverse effects , Female , Humans , Intestinal Perforation/epidemiology , Male , Middle Aged , Postoperative Complications/epidemiology , Retrospective Studies
16.
Phys Med Biol ; 53(23): 6861-77, 2008 Dec 07.
Article in English | MEDLINE | ID: mdl-19001701

ABSTRACT

This paper describes a method of film dosimetry used to measure the peak-to-valley dose ratios for synchrotron microbeam radiation therapy (MRT). Two types of radiochromic film (manufactured by International Specialty Products, NJ, USA) were irradiated in a phantom and also flush against a microbeam collimator (beam width 25 microm, centre-to-centre spacing 200 microm) on beamline BL28 B2 at the SPring-8 synchrotron. Four experiments are reported: (1) the HD-810 and EBT varieties of radiochromic film were used to record 'peak' dose and 'valley' (regions in between peaks) dose, respectively; (2) a stack of HD-810 film sheets was microbeam-irradiated and analysed to investigate a possible dose build-up effect; (3) a very high MRT dose was delivered to HD-810 film to elicit a measurable valley dose to compare with the result obtained using broad beam radiation; (4) the half value layer of the beam with and without the microbeam collimator was measured to investigate the effect of the collimator on the beam quality. The valley dose obtained for films placed flush against the collimator was approximately 0.2% of the peak dose. Within the water phantom, the valley dose had increased to between 0.7 and 1.8% of the peak dose, depending on the depth in the phantom. We also demonstrated, experimentally and by Monte Carlo simulation, that the dose is not maximal on the surface and that there is a dose build-up effect. The microbeam collimator did not make an appreciable difference to the beam quality. The values of the peak-to-valley ratio reported in this paper are higher than those predicted by previously published Monte Carlo simulation papers.


Subject(s)
Film Dosimetry/methods , Radiotherapy, High-Energy , Synchrotrons , Calibration , Dose-Response Relationship, Radiation , Film Dosimetry/instrumentation , Humans , Monte Carlo Method , Phantoms, Imaging , Radiotherapy Dosage
17.
Phys Med Biol ; 53(21): 6065-77, 2008 Nov 07.
Article in English | MEDLINE | ID: mdl-18843172

ABSTRACT

Phase contrast x-ray imaging can provide detailed images of lung morphology with sufficient spatial resolution to observe the terminal airways (alveoli). We demonstrate that quantitative functional and anatomical imaging of lung ventilation can be achieved in vivo using two-dimensional phase contrast x-ray images with high contrast and spatial resolution (<100 microm) in near real time. Changes in lung air volume as small as 25 microL were calculated from the images of term and preterm rabbit pup lungs (n = 28) using a single-image phase retrieval algorithm. Comparisons with plethysmography and computed tomography showed that the technique provided an accurate and robust method of measuring total lung air volumes. Furthermore, regional ventilation was measured by partitioning the phase contrast images, which revealed differences in aeration for different ventilation strategies.


Subject(s)
Lung Volume Measurements/methods , Lung/physiology , Animals , Plethysmography , Rabbits , Radiography , Reproducibility of Results , Respiration , X-Rays
18.
J Mol Biol ; 362(2): 327-33, 2006 Sep 15.
Article in English | MEDLINE | ID: mdl-16919294

ABSTRACT

The peptide hormone insulin forms a spherical aggregate, called a spherulite, at low pH and high temperature. A spherulite is composed of a core and many fibrils extending from it. These fibrils are thought to be amyloid fibers with a beta-sheet structure. In the present study, spherulites with a diameter of 50-100 microm were examined by X-ray fiber diffraction using a 6 microm beam. When a spherulite was scanned with the microbeam and the observed diffraction patterns were arranged in a two-dimensional array, the direction of the scatter was centrosymmetric, demonstrating a symmetric growth of fibrils. There were diffraction peaks at Bragg spacings of 23 nm, 3.3 nm and 1.2 nm in the direction perpendicular to the fibrils and 0.48 nm along the fibrils. The 0.48 nm reflection shows that the hydrogen bonds between beta-strands are along the fibril. The 23 nm reflection corresponds to the separation between fibrils, the 3.3 nm reflection is due to the arrangement of protofilaments, and the 1.2 nm reflection arises from the arrangement of peptide chains. On the basis of these results, a model of a fibril with an extended insulin molecule is proposed.


Subject(s)
Insulin/chemistry , Protein Conformation , X-Ray Diffraction/methods , Amino Acid Sequence , Amyloid/chemistry , Animals , Cattle , Molecular Sequence Data , Particle Size
19.
Biochim Biophys Acta ; 1214(3): 279-87, 1994 Oct 06.
Article in English | MEDLINE | ID: mdl-7918610

ABSTRACT

Monoester fraction of rat skin surface lipid has been shown to contain more than trace amounts of branched-long-chain fatty acids (BCFAs) of the iso and anteiso series. These BCFAs are biosynthesized using either branched-chain amino acids (BCAAs) or branched-chain alpha-keto acids (BCKAs), or using both of them as precursor. This study has been carried out to address which precursor, BCAAs or BCKAs in the circulation, are mainly utilized for biosynthesis of BCFAs. Dietary supplement of [14C]-valine and isoleucine-induced sharp rise of serum concentration of these two amino acids and their respective alpha-keto acids, and elevated the levels of related BCFAs and branched-chain fatty alcohols in the monoester fraction. A larger proportion of label in the total skin surface lipid was found in the monoester fraction in which fatty acid and alcohol accounted for approx. 80% of total radioactivity. Incorporation of intravenously administered [14C]-BCAAs and BCKAs into the monoester fraction revealed that BCAAs were far better as precursors than BCKAs for BCFA biosynthesis in rat skin. Among three BCAAs, leucine differed from valine or isoleucine in that this amino acid was primarily utilized for production of straight-chain fatty acids rather than for production of related BCFA.


Subject(s)
Amino Acids, Branched-Chain/pharmacology , Fatty Acids/biosynthesis , Skin/metabolism , Amino Acids, Branched-Chain/metabolism , Animals , Carbon Radioisotopes , Fatty Acids/chemistry , Fatty Alcohols/chemistry , Fatty Alcohols/metabolism , Isoleucine/pharmacology , Keto Acids/pharmacology , Leucine/pharmacology , Lipids/chemistry , Lipids/isolation & purification , Male , Rats , Rats, Wistar , Valine/pharmacology
20.
Diabetes ; 44(7): 744-52, 1995 Jul.
Article in English | MEDLINE | ID: mdl-7789642

ABSTRACT

Intercellular adhesion molecule 1 (ICAM-1) plays an important role in the pathogenesis of insulin-dependent diabetes mellitus (IDDM) by being involved in the extravasation of lymphocytes from the circulation into the inflamed pancreas. However, the mechanism of beta-cell destruction by which expression of ICAM-1 on beta-cells may facilitate adhesion of effector cells still remains to be elucidated. Several lines of evidence suggest that this adhesion molecule is involved in the destruction of pancreatic beta-cells by killer lymphocytes in the NOD mouse, which shows an autoimmune diabetic syndrome similar to that of human IDDM. Immunohistochemical study under light microscopy demonstrated that all of the mononuclear cells infiltrating the islets strongly expressed ICAM-1 and leukocyte function-associated antigen 1 (LFA-1), a counterreceptor of ICAM-1, whereas ICAM-1 expression on islet cells was not apparent. However, immunohistochemical staining under electron microscopy revealed that islet beta-cells adjacent to infiltrating lymphocytes were clearly stained by an anti-ICAM-1 monoclonal antibody (mAb). Flow cytometric analysis showed that the ICAM-1 expression on NOD islet cells and NOD-derived insulinoma cells (MIN6N8a) was inducible by interferon (IFN)-gamma or tumor necrosis factor-alpha. These cytokines had an additive effect on the ICAM-1 induction. Susceptibility of MIN6N8a cells to lysis by a NOD islet-derived CD8+ cytotoxic T-cell clone was greatly enhanced by IFN-gamma pretreatment, and this enhancement was abolished by anti-ICAM-1 and anti-LFA-1 mAbs. When both mAbs were administered into NOD mice with spontaneous or adoptively transferred diabetes, the development of diabetes was significantly prevented.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Autoimmune Diseases/immunology , Cytotoxicity, Immunologic , Diabetes Mellitus, Type 1/immunology , Intercellular Adhesion Molecule-1/biosynthesis , Islets of Langerhans/immunology , T-Lymphocytes, Cytotoxic/immunology , Animals , Autoimmune Diseases/pathology , Diabetes Mellitus, Type 1/pathology , Female , Flow Cytometry , Gene Expression/drug effects , Humans , Immunohistochemistry , Immunotherapy, Adoptive , Insulinoma/immunology , Intercellular Adhesion Molecule-1/analysis , Interferon-gamma/pharmacology , Islets of Langerhans/pathology , Islets of Langerhans/ultrastructure , Lymphocyte Function-Associated Antigen-1/analysis , Lymphocyte Function-Associated Antigen-1/biosynthesis , Male , Mice , Mice, Inbred NOD , Microscopy, Immunoelectron , Pancreatic Neoplasms/immunology , Spleen/immunology , Tumor Cells, Cultured , Tumor Necrosis Factor-alpha/pharmacology
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