[en] In order to ascertain if early changes in cytosolic free calcium concentration [Ca2+] are correlated with either activation, as defined by 3H-uridine incorporation or increase in cell size, or induction of DNA synthesis, 3H-thymidine incorporation, murine B lymphocytes were stimulated with preparations of lipopolysaccharide (LPS), rabbit anti-mouse Fab (RAMFab), and 12-O-tetradecanoyl-phorbol-13-acetate (TPA). LPS, although a potent inducer of 3H-thymidine incorporation does not cause an increase in [Ca2+]. F(ab')2RAMFab at 50 μs ml causes a 6X increase in 3H-thymidine incorporation as opposed to a 2-3X increase at 10 μg/ml. IgG-RAMFab at concentrations up to 50 μg/ml neither induces DNA synthesis nor activates cells by any criteria, including 3H-uridine incorporation, increase in cell size, and increase in I-A expression. Both RAMFab causes increases in [Ca2+] that saturate at 10 μg/ml. Minimally proliferative doses of TPA inhibit the increase in [Ca2+] caused by both preparations of RAMFab. However, B cells pretreated with TPA and then stimulated with 2 or 10 μg/ml of either preparation of RAMFab showed increases of 10 X in 3H-uridine and 100X in 3H-thymidine incorporation. These data demonstrate that there appears to be no correlation between early changes in [Ca2+] and either activation or induction of DNA synthesis in murine B cells
Journal
Federation Proceedings. Federation of American Societies for Experimental Biology; ISSN 0014-9446; 
; CODEN FEPRA; v. 45(4); p. 982
; CODEN FEPRA; v. 45(4); p. 982
[en] Proton motions will show up predominantly in the spectra of neutron inelastic scattering because of its high cross-section. Infrared absorption on the other hand will indicate only the, modes allowed by selection rules. Therefore the motions of the proton and their characteristics can sometimes be determined by comparing the results of the two techniques. The spectra of KH2PO4 in the region 200 to 700 cm-1 are similar in both methods; one observes two rather sharp lines at 540 and 410 cm-1 that are PO4- characteristic modes. On the other hand, one gets in KH2PO4 two peaks in infrared absorption; a sharp one at 540 cm-1 and a very broad one from 450 to 250 cm-1. In the neutron inelastic scattering spectra, one observes just one broad peak extended from 600 to 250 cm-1. These results lead to the conclusion that the proton is involved also in modes of vibrations that are not characteristic to PO-4 group and that these low proton frequency modes are prohibited by infrared selection rules. Low proton modes of this type can be explained as being caused by proton motion in a slightly asymmetric double minima potential. The vibrational ground level of the proton is then split into two closely lying levels with a separation of about 400 cm-1. The wave functions of the lower level are concentrated in the deeper well while those of the higher one are concentrated in the upper well. Infrared selection rules predict low intensity to this mode in infrared absorption but it will show up clearly in neutron inelastic scattering. The assumption of proton tunnelling in KH2PO4 type crystals, that is strongly supported by the results of this work, leads to an explanation of phase transition on these interesting materials, namely the ferroelectric Curie point and melting point. (author)
[fr]
Us mouvements des protons apparaissent surtout dans les spectres de la diffusion inélastique des neutrons, en raison de leur forte section efficace. En revanche, l'absorption infrarouge ne met en évidence que les modes permis par les lois de sélection. U est donc parfois possible d'établir les mouvements du proton et leurs caractéristiques en comparant les résultats obtenus à l’aide de ces deux méthodes. Les spectres de KH2PO4 dans la région comprise entre 200 et 700 cm-1 sont semblables avec l'une et l'autre méthodes; on observe à 540 et 410 cm-1 deux raies assez nettes qui sont les modes caractéristiques de PO4-. D'autre part, on observe dans KH2PO4 deux pics d'absorption infrarouge, un pic aigu á 540 cm-1, et un pic étalé de 450 à 250 cm-1. Dans les spectres de la diffusion inélastique des neutrons, on n'observe qu'un seul pic très étalé qui s'étend de 600 à 250 cm-1. Ces résultats amènent à conclure que le proton entre également en jeu dans des modes de vibrations qui ne sont pas caractéristiques du groupe PO4- et que ces modes à basse fréquence sont écartés par les lois de sélection infrarouge. On peut attribuer les modes protoniques à basse fréquence de cette nature aux mouvements des protons dans un potentiel à deux minima légèrement asymétriques. Le niveau bas des vibrations des protons se dédouble alors en deux niveaux rapprochés, séparés d'environ 400 cm-1. Les fonctions d’onde du niveau bas sont concentrées dans le puits inférieur, tandis que celles du niveau plus élevé sont concentrées dans le puits supérieur. Les règles de sélection infrarouge prévoient que ce mode aura une faible intensité dans l'absorption infrarouge, mais il apparait nettement dans la diffusion inélastique des neutrons. L'hypothèse de l'existence d’un effet «tunnel» dans les cristaux du type KH2PO4, qui est très bien corroborée par les résultats de ces travaux, fournit une explication de la transition de phase pour ces cristaux intéressants, à savoir le point de Curie et le point de fusion ferroélectriques. (author)[es]
Los movimientos protónicos predominan en los espectros de dispersión inelástica de neutrones debido a la elevada sección eficaz de éstos. Pro otra parte, la absorción en la zona infrarroja indica solamente los modos permitidos por las reglas de selección. La comparación de los resultados obtenidos por ambas técnicas permite algunas veces determinar los movimientos de los protones y sus características. Los espectros del KH2PO4 en la región de 200 a 700 cm-1 obtenidos por ambos métodos son similares ; se observan dos rayas bastante nítidas a 540 y 410 cm-1 que corresponden a modos característicos del grupo PO4-. Por otra parte, el KH2PO4 origina dos máximos de absorción en el infrarrojo; uno nítido a 540 cm-1 y otro muy ancho entre 450 y 250 cm-1. Hn el espectro de dispersión inelástica de neutrones se observa solamente un máximo muy ancho que se extiende desde 600 hasta 250 cm-1. Dichos resultados sugieren que el protón interviene también en modos vibratorios que no son característicos del grupo PO4- y Que estos modos de frecuencia protónica más baja son prohibidos de conformidad con las reglas de selección en el infrarrojo. Dichos modos inferiores pueden explicarse como consecuencia de los movimientos de los protones en un potencial de doble mínimo, ligeramente asimétrico. En estas condiciones, el nivel vibratorio fundamental del protón se desdobla en otros dos niveles próximos, con una separación de unos 400 cm-1. Las funciones ondulatorias del nivel inferior se concentran en el pozo más profundo, mientras que las del superior se concentran en el pozo más alto. Las reglas de selección en el infrarrojo indican que la intensidad de este modo en la absorción infrarroja será reducida, pero que aparecerá claramente en la dispersión inelástica de neutrones. Los resultados obtenidos por los autores confirman la existencia de un efecto túnel para los protones en los cristales del tipo del KH2PO4, lo que explicaría las transiciones de fase (punto de Curie ferroeléctrico y punto de fusión) en estos interesantes materiales. (author)[ru]
Dvizhenija protona budut zametno vydeljat'sja v spektrah neuprugogo rassejanija nejtronov blagodarja ego bol'shomu poperechnomu secheniju. S drugoj storony, infrakrasnoe pogloshhenie ukazyvaet lish' na kolebanija, podpadajushhie pod pravila otbora. Pojetomu dvizhenija protonov i ih harakteristiki mozhno inogda opredelit', sravnivaja rezul'taty jetih dvuh metodov. Spektry KH2PO4 v predelah ot 200 do 700 cm-1 javljajutsja analogichnymi pri oboih metodah: nabljudajutsja dve dovol'no ostrye linii pri 540 i 410 cm-1, chto javljaetsja harakteristicheskoj formoj kolebanija PO-4. S drugoj storony, pri infrakrasnom pogloshhenii poluchajutsja dva pika v KH2PO4: ostryj pik pri 540 cm-1 i ochen' shirokij v predelah ot 450 do 250 cm-1. V spektrah neuprugogo rassejanija nejtronov mozhno nabljudat' tol'ko odin shirokij pik v predelah ot 600 do 250 cm-1. Jeti rezul'taty privodjat k zakljucheniju, chto proton svjazan takzhe s formami kolebanij, kotorye ne javljajutsja harakternymi dlja gruppy PO-4 , i chto jeti kolebanija nizkoj chastoty ne podpadajut pod pravila infrakrasnogo otbora. Protonnye kolebanija jetogo tipa mogut byt' objasneny dvizheniem protona v neskol'ko asimmetrichnom potenciale s dvumja minimumami. Osnovnoj kolebatel'nyj uroven' protona rasshhepljaetsja zatem na dva blizko raspolozhennyh urovnja s razdeleniem okolo 400 cm-1. Volnovye funkcii bolee nizkogo urovnja sosredotocheny v bolee glubokoj jame, v to vremja kak volnovye funkcii bolee vysokogo urovnja sosredotocheny v verhnej jame. Pravila infrakrasnogo otbora predskazyvajut nizkuju intensivnost' dlja jetoj formy kolebanij pri infrakrasnom pogloshhenii, no ona chetko vydeljaetsja pri neuprugom rassejanii nejtronov. Predpolozhenie, chto proton imeet tunnel'nyj jeffekt v kristallah tipa KH2PO4, chto opredelenno podtverzhdaetsja rezul'tatami dannoj raboty, pozvoljaet ob'jasnit' fazovoe prevrashhenie v jetih interesnyh materialah, a imenno, ferrojelektricheskuju tochku kjuri i tochku plavlenija. (author)Source
International Atomic Energy Agency, Vienna (Austria); 590 p; Jun 1965; p. 325-331; Symposium on Inelastic Scattering of Neutrons; Bombay (India); 15-19 Dec 1964; IAEA-SM--58/26; ISSN 0074-1884; ; 17 refs., 3 figs.
; 17 refs., 3 figs.
[en] Background: Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a novel method to investigate cartilaginous and fibrocartilaginous structures. Purpose: To investigate the contrast dynamics in hyaline and fibrous cartilage of the glenohumeral joint after intraarticular injection of gadopentetate dimeglumine. Material and Methods: Transverse T1 maps were acquired on a 1.5T scanner before and after intraarticular injection of 2.0 mmol/l gadopentetate dimeglumine in five cadaveric shoulders using a dual flip angle three-dimensional gradient echo (3D-GRE) sequence. The acquisition time for the T1 maps was 5 min 5 s for the whole shoulder. Measurements were repeated every 15 min over 2.5 hours. Regions of interest (ROIs) covering the glenoid cartilage and the labrum were drawn to assess the temporal evolution of the relaxation parameters. Results: T1 of unenhanced hyaline cartilage of the glenoid was 568±34 ms. T1 of unenhanced fibrous cartilage of the labrum was 552±38 ms. Significant differences (P=0.002 and 0.03) in the relaxation parameters were already measurable after 15 min. After 2 to 2.5 hours, hyaline and fibrous cartilage still demonstrated decreasing relaxation parameters, with a larger range of the T1(Gd) values in fibrous cartilage. T1 and ?R1 values of hyaline and fibrous cartilage after 2.5 hours were 351±16 ms and 1.1±0.09/s, and 332±31 ms and 1.2±0.1/s, respectively. Conclusion: A significant decrease in T1(Gd) was found 15 min after intraarticular contrast injection. Contrast accumulation was faster in hyaline than in fibrous cartilage. After 2.5 hours, contrast accumulation showed a higher rate of decrease in hyaline cartilage, but neither hyaline nor fibrous cartilage had reached equilibrium
Journal
Acta Radiologica (Online); ISSN 1600-0455; ; v. 50(1); p. 86-92
; v. 50(1); p. 86-92
[en] We evaluated high-resolution magnetic resonance imaging (MR) using a 47-mm microscopy surface coil in comparison to 16-slice multislice CT (MSCT) for postsurgical imaging of reconstructed orbital walls. Twenty-five patients with 27 internal orbital wall fractures were imaged prospectively after reconstruction with resorbable polydioxanone sulfate (PDS) sheets. Coronal high-quality T1- and T2-weighted MR images were obtained with an in-plane resolution of 350 μm within a measure time of 6-7 min for each sequence. Nineteen symptomatic patients underwent MSCT as the current gold standard. In MRI the PDS foil appears in T1- and T2-weighted images as a thin, low-signal-intensity linear structure. In CT it appears hyperdense in comparison to soft tissue and slightly hypodense in comparison to cortical bone. PDS foils could be clearly depicted in 20 out of 25 patients (80%) with MRI and in 13 out of 19 patients (68%) with MSCT. An inadequate foil position or size could be diagnosed in eight patients with MRI and in only three patients with MSCT. In ten symptomatic patients secondary surgery could be avoided because of regular MRI findings except mild hematoma and muscle edema. High-resolution MRI of the orbit using a 47-mm microscopy coil is a promising method to accurately demonstrate normal and pathologic conditions in symptomatic patients after orbital wall reconstruction with PDS foils. (orig.)
Journal
[en] Local tumor control and functional outcome after linac-based stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) for vestibular schwannoma (VS) were assessed. In all, 250 patients with VS were treated: 190 patients with tumors < 2 cm diameter underwent SRS and 60 patients with tumors >2 to 3.5 cm underwent FSRT. Dose prescription for all cases with SRS (n = 190, 76 %) was 13.5 Gy. For FSRT, mainly two hypofractionated schedules (n = 60, 24 %) with either 7 fractions of 5 Gy (total dose: 35 Gy; n = 35) or 11 fractions of 3.8 Gy (total dose: 41.8 Gy; n = 16) were used. The primary endpoint was local tumor control. Secondary endpoints were symptomatic control and morbidity. The median follow-up was 33.8 months. The 3-year local tumor control was 88.9 %. Local control for SRS and FSRT was 88 and 92 %, respectively. For FSRT with 35 and 41.8 Gy, local control was 90 and 100 %, respectively. There were no acute reactions exceeding grade I. In 61 cases (24.4 % of the entire cohort), trigeminal neuralgia was reported prior to treatment. At last follow-up, 16.3 % (10/61) of those patients reported relief of pain. Regarding facial nerve dysfunction, 45 patients (18 %) presented with symptoms prior to RT. At the last follow-up, 13.3% (6/45) of those patients reported a relief of dysesthesia. Using SRS to treat small VS results in good local control rates. FSRT for larger lesions also seems effective. Severe treatment-related complications are not frequent. Therefore, image-guided stereotactic radiotherapy is an appropriate alternative to microsurgery for patients with VS. (orig.)
[de]
Wir analysierten die lokale Kontrolle und die funktionellen Verlaeufe bei Patienten mit einem Vestibularisschwannom (VS), die sich einer linacbasierten stereotaktischen Radiochirurgie (SRS) oder einer fraktionierten stereotaktischen Radiotherapie (FSRT) unterzogen. Zwischen 1998 und 2008 wurden 250 Patienten mit einem VS behandelt. In dieser Kohorte wurden 190 Faelle mit einem Tumor <2 cm mit SRS und 60 Faelle mit einem Tumor >2 cm bis 3,5 cm mit FSRT behandelt. Die verschriebene Dosis betrug fuer alle SRS-Faelle (n = 190, 76 %) 13,5 Gy im Isozentrum. Fuer die FSRT wurden zwei Schemata angewendet: 7 Fraktionen 5 Gy (Gesamtdosis 35 Gy; n = 35) und 11 Fraktionen 3,8 Gy (Gesamtdosis 41,8 Gy; n = 16). Der primaere Endpunkt war die lokale Kontrolle. Sekundaere Endpunkte waren Symptomkontrolle und Toxizitaet. Nach einer medianen Nachuntersuchung von 33,8 Monaten betrug die 3-Jahres-Lokalkontrolle 88,9 % (bei 11,1 % Progress). Die lokale Kontrolle lag mit SRS bei 88 % und mit FSRT bei 92 %. Fuer die FSRT-Subgruppe betrug die lokale Kontrolle mit 35 Gy 90 % und mit 41,8 Gy 100 %. Kein Patient litt unter einer Toxizitaet vom Grad > 1. In 61 Faellen (24,4 % des Gesamtkollektivs) wurde vor der Therapie eine Trigeminusneuralgie berichtet, zur Zeit der Analyse litten noch 16,3 % (10/61) unter derselben. Eine Faszialisdysfunktion wiesen vor RT 45 Patienten (18 %) auf. Zum Follow-up-Zeitpunkt berichteten 13,3% (6/45) dieser Patienten von einer Linderung der Dysaesthesie. Die linacbasierte SRS zur Behandlung kleiner VS weist hohe lokale Kontrollraten auf, die vergleichbar mit der Mikrochirurgie sind. FSRT scheint auch fuer groessere Laesionen effektiv. FSRT zeigt ebenfalls gute Ergebnisse in Bezug auf Sicherheit und Outcome. Ernsthafte behandlungsbedingte Nebenwirkungen sind nicht haeufig. Der Vergleich von SRS und FSRT mit der Mikrochirurgie in Bezug auf Morbiditaet und Funktion der Hirnnerven zeigt eine Aequivalenz der Methoden. SRS kann fuer Patienten mit VS als eine gute Alternative zur Mikrochirurgie angesehen werden. (orig.)Journal
[en] Purpose: To evaluate the diagnostic potential of a multi-factor analysis of morphometric parameters and magnetic resonance (MR) signal characteristics of a mass and peritumoral area to distinguish solitary supratentorial metastasis from glioblastoma multiforme (GBM). Materials and Methods: MR examinations of 51 patients with histologically proven GBM and 44 with a single supratentorial metastasis were evaluated. A large variety of morphologic criteria and MR signal characteristics in different sequences were analyzed. The data were subjected to logistic regression to investigate their ability to discriminate between GBM and cerebral metastasis. Receiver-operating characteristic (ROC) analysis was used to select an optimal cut-off point for prediction and to assess the predictive value in terms of sensitivity, specificity, and accuracy of the final model. Results: The logistic regression analysis revealed that the ratio of the maximum diameter of the peritumoral area measured on T2-weighted images (d T2) to the maximum diameter of the enhancing mass area (d T1, post-contrast) is the only useful criterion to distinguish single supratentorial brain metastasis from GBM with a lower ratio favoring GBM (accuracy 68 %, sensitivity 84 % and specificity 45 %). The cut-off point for the ratio d T2/d T1 post-contrast was calculated as 2.35. Conclusion: Measurement of maximum diameters of the peritumoral area in relation to the enhancing mass can be evaluated easily in the clinical routine to discriminate GBM from solitary supratentorial metastasis with an accuracy comparable to that of advanced MRI techniques. (orig.)
Journal
RoeFo - Fortschritte auf dem Gebiete der Roentgenstrahlen und der bildgebenden Verfahren; ISSN 1438-9029; ; CODEN RFGNDO; v. 185(3); p. 235-240
; CODEN RFGNDO; v. 185(3); p. 235-240
[en] To assess how ASIR (adaptive statistical iterative reconstruction) contributes to dose reduction and affects image quality of non-contrast cranial computed tomography (cCT). Non-contrast emergency CT scans of the head acquired in 177 patients were evaluated. The scans were acquired and processed using four different protocols: Group A (control): 120 kV, FBP (filtered back projection) n=71; group B1: 120 kV, scan and reconstruction performed with 20 % ASIR (blending of 20 % ASIR and 80 % FBP), n=86; group B2: raw data from group B1 reconstructed using a blending of 40 % ASIR and 60 % FBP, n=74; group C1: 120 kV, scan and reconstruction performed with 30 % ASIR, n=20; group C2: raw data from group C1 reconstructed using a blending of 50 % ASIR and 50 % FBP, n=20. The effective dose was calculated. Image quality was assessed quantitatively and qualitatively. Compared to group A, groups B1/2 and C1/2 showed a significantly reduced effective dose of 40.4 % and 73.3 % (p < 0.0001), respectively. Group B1 and group C1/2 also showed significantly reduced quantitative and qualitative image quality parameters. In group B2, quantitative measures were comparable to group A, and qualitative scores were lower compared to group A but higher compared to group B1. Diagnostic confidence grading showed groups B1/2 to be adequate for everyday clinical practice. Group C2 was considered acceptable for follow-up imaging of severe acute events such as bleeding or subacute stroke. Conclusion: Use of ASIR makes it possible to reduce radiation significantly while maintaining adequate image quality in non-contrast head CT, which may be particularly useful for younger patients in an emergency setting and in follow-up.
Journal
RoeFo - Fortschritte auf dem Gebiete der Roentgenstrahlen und der Bildgebenden Verfahren; ISSN 1438-9029; ; CODEN RFGNDO; v. 188(2); p. 155-162
; CODEN RFGNDO; v. 188(2); p. 155-162