Acute blinding sinusitis

Sinusitis may produce blindness, and deterioration in visual acuity is a strong indication for urgent admission and possible surgery.     

Tissue distribution and magnetic resonance spin lattice relaxation effects of gadolinium-DTPA

Gadolinium-DTPA complex (Gd-DTPA) is a potential clinical magnetic resonance (MR) contrast agent that enhances images primarily by decreasing spin-lattice relaxation time (T1) in tissues in which it localizes. This study was designed to determine the immediate tissue distribution of intravenously administered Gd-DTPA in selected organs of interest as a function of administered dose and tissue Gd-DTPA concentration. An intravenous bolus of Gd-DTPA with a tracer quantity of Gd-153 was administered to three groups of rabbits at the following doses: 0.01 mM/kg (n = 6); 0.05 mM/kg (n = 6); 0.10 mM/kg (n = 6). A control group received sham injections. Five minutes after Gd-DTPA was administered, all animals were killed; samples of serum, lung, heart, kidney, liver, and spleen were analyzed in a 0.25 T MR spectrometer to measure T1, and then in a gamma well counter to determine tissue concentration of Gd-DTPA. Tissue distribution (per cent dose/tissue weight in g) at five minutes after injection was proportionally constant over the range of doses given. Tissue concentration varied linearly with injected dose (r greater than 0.98 for all tissues). Relaxation rate (1/T1) varied linearly with injected dose and with tissue Gd-DTPA concentration (r greater than 0.97 for all tissues). The order of tissue relaxation rate response to a given dose was: kidney greater than serum greater than lung greater than heart greater than liver greater than spleen. We conclude that because of its extracellular distribution and linear relaxation rate versus concentration relationship, Gd-DTPA enhancement in MR images may be a good marker of relative organ perfusion.     

Magnetic resonance imaging and computed tomography features of nasopharyngeal carcinoma with maxillary sinus involvement

Anterior spread of nasopharyngeal carcinoma (NPC) may infiltrate the maxillary sinus. In a prospective study of 114 patients comparing magnetic resonance imaging (MRI) and computed tomography (CT) in the staging of NPC, 10 (9%) patients were noted to have tumour infiltration of the maxillary sinuses. All of the patients except one had associated infiltration of the sphenoidal sinuses indicating advanced local spread. Computed tomography was excellent in outlining the extent of bony erosion and associated soft tissue mass within the antra. T1-weighted images could not demonstrate bony erosions directly although soft tissue extension into the sinuses could be clearly visualized. Both CT and MRI showed good demarcation between tumour and mucosal thickening within the maxillary sinus. Although MRI demonstrated soft tissue involvement more elegantly than CT, it did not appear to offer significantly more information that may affect clinical management.     

Anatomy of the external ear canal: a new technique for making impressions

The study of the topographical and three dimensional anatomy of the human external auditory canal and tympanic membrane has been simplified by applying a dental impression technique to the cadaver ear. A light silicone resin was catalyzed and syringed into the anterior recess and then into the entire external canal. Analysis of these impressions showed them to compare well with earlier morphological techniques, and to provide a durable and reliable replica of the surface of the tympanic membrane, the interior of the external auditory canal, and the lateral surface of the pinna. The resulting impressions displayed the anatomical features of the external auditory canal in a unique three-dimensional fashion which was also suitable for measurement of the anatomical features of the canal.     

一些紫草素衍生物的园二色谱研究

从四川密花滇紫草(Onosma confertum W.W.Smith)和新疆软紫草[Arnebia euchroma (Royle) Johust]的根中分到九个紫草素衍生物,其中七个为手性化合物。测定了它们的CD谱和UV谱,结果得到三对几乎完全对称的CD谱图和完全相同的UV谱图、确定了四川密花滇紫草成分均为R构型;新疆软紫草成分均为S构型。