Petrosal sinus sampling for Cushing syndrome: anatomical and technical considerations. Work in progress

ACTH-producing microadenomas of the pituitary gland drain unilaterally into the adjacent cavernous sinus; therefore, petrosal sinus sampling to distinguish pituitary from ectopic-ACTH syndromes must always be performed bilaterally. A negative finding from a unilateral petrosal sinus sample does not exclude the presence of a contralateral ACTH-producing microadenoma. Hemiresection of the pituitary gland based on results of bilateral sampling can be performed if the adenoma is too small to be recognized at surgery. Large pituitary adenomas produce elevated ACTH levels in the petrosal sinuses bilaterally. However, if plain radiographs or CT scans provide unequivocally positive findings in Cushing syndrome (less than 20%), inferior petrosal sinus sampling is not indicated.     

Web-based Three-dimensional Virtual Body Structures: W3D-VBS

Major efforts are being made to improve the teaching of human anatomy to foster cognition of visuospatial relationships. The Visible Human Project of the National Library of Medicine makes it possible to create virtual reality-based applications for teaching anatomy. Integration of traditional cadaver and illustration-based methods with Internet-based simulations brings us closer to this goal.Web-based three-dimensional Virtual Body Structures (W3D-VBS) is a next-generation immersive anatomical training system for teaching human anatomy over the Internet. It uses Visible Human data to dynamically explore, select, extract, visualize, manipulate, and stereoscopically palpate realistic virtual body structures with a haptic device. Tracking user’s progress through evaluation tools helps customize lesson plans. A self-guided “virtual tour” of the whole body allows investigation of labeled virtual dissections repetitively, at any time and place a user requires it.One of the most difficult tasks in learning gross anatomy is to comprehend the three-dimensional visuospatial relations of anatomical structures. Thus, creation of realistic three-dimensional structures of human anatomy has been a goal of medical professionals and computer scientists for many years.Traditionally, cadavers and 2D illustrations with labels to identify structures have been used to cognitively integrate anatomical information for visualizing three-dimensional structures. Our own research in this area is directed towards leveraging advances in information and virtual reality technologies to design an anatomical training information system that allows a user to build three-dimensional interactive simulations “in-front-of-their-eyes” over the Internet.The design of our system, Web-based three-dimensional Virtual Body Structures (W3D-VBS), is based on the concept of “what you want is what you get” for interactive assembly and efficient viewing, exploring, and manipulating hundreds of organs, and their connected (or proximal) structures. The user does not require a medical background to use this system or have to be a medical student to learn from it.     

海洋环肽噻唑氨基酸片断(D-Val)Thz的合成

近几年分离到的几个海洋环肽(ulicyclamide,ulithiacyclamide,patellamides,scidiacyclamide,dolastatin)的分子中都含有噻唑氨基酸结构。由于这些环肽有强烈的生理活性而引起人们广泛的研究。几个课题组都在从事其全合成及结构与生理活性关系的研究工作。而其中噻唑氨基酸是全合成中关键片断,对整个分子的生理活性也可能起着重要的作用。合成噻唑氨基酸有以下几种方法:     

Fluorescein pattern of the choriocapillaris in the neonatal rhesus monkey.

Seven neonatal rhesus monkeys were studied by serial fundus photography and fluorescein angiography at weekly intervals during the first 12 weeks of life. The neonatal rhesus showed little pigmentation of the fundus during the first six weeks of life. The fluorescein angiograms showed a definite sequential as well as segmental filling pattern at the level of the choriocapillaris. This filling pattern was based on individual units called lobules. In addition there was a segmental flow in the macula; that is, the nasal macula filled before the temporal macula.     

Studies on the role of nickel in the ruminant

Lambs were fed 6 to 7% of metabolic body weight per day of a basal purified diet low in nickel (65 ppb) or the basal diet plus 5 ppm nickel for a 97 day period in an attempt to demonstrate an essential role for nickel in the ovine. Weight gains for the entire period and digestibility of dry matter and of protein at 28 and 56 days were not different between the two groups. At 28 days, but not at 56 days, urinary nitrogen was less and percentage retention of absorbed nitrogen was greater in the supplemented lambs. Total serum proteins were higher at 56 days and serum alanine transaminase was higher throughout the experiment in the nickel supplemented lambs, but only significantly so at 56 days. When lambs were given an oral dose of 65Ni, the low nickel lambs tended to excrete more in the feces and retained less in the kidney, lung, and liver at 72 hours post dosing. The major excretory route of nickel was via the feces. The kidney retained the highest concentration of 65Ni of the organs examined.     

Expanding spectrum of pulmonary disease caused by nontuberculous mycobacteria

The clinical and radiographic features of 35 patients with nontuberculous mycobacterial (NTMB) pulmonary infections were reviewed. Radiographs of half the patients showed the pattern of cavitary upper-lobe infiltrates typical of reactivation tuberculosis; those of the other half had a radiographic pattern characterized by patchy, nodular infiltrates without an upper-lobe prevalence. Approximately half of the latter group showed multiple small cavities resembling those seen in bronchiectasis. These results suggest that studies in which the diagnosis of NTMB infection has been made primarily from sputum cultures may have been biased toward detecting cavitary disease. The spectrum of pulmonary disease caused by NTMB appears to be larger than previously appreciated. An enhanced awareness of alternate presentations of NTMB infections may result in earlier diagnosis.