Assessment of Free Dye in Solutions of Dual-Labeled Antibody Conjugates for <Emphasis Type="Italic">In Vivo</Emphasis> Molecular Imaging

Purpose  

Recent preclinical and clinical studies show that dyes that excite and fluoresce in the near-infrared range may be used for tracking and detecting disease targets in vivo. A method for quantifying free dye molecules in antibody conjugate preparations is required for agent batch release and for translation into the clinic.     

美国教学医院教师专业发展的全国性调查

在当前医学教育持续变革的背景中,医学教师的专业发展成为广泛关注的焦点.为了解目前美国以提高教师的教学技能为目标的教师专业发展(faculty development,FD)活动的参与率、课程设计、教学方法和评估策略等情况,美国约翰·霍普金斯大学预防、流行病学和临床研究中心采取邮件调查的方式,对美国277家教学医院进行了调查.     

Sleep disorders and airway obstruction in newborns and infants

For most infants with a disorder of breathing control or airway obstruction, cause and management can be defined with a careful history and a few simple diagnostic tests. Pneumograms and multichannel studies can identify patterns of apnea and associated hypoxemia and can be used to assess therapeutic efficacy. For the majority of infants with disordered breathing, the outcome is favorable and conservative management is appropriate. More extensive diagnostic evaluation is reserved for infants with severe apnea or those with evidence of a significant contributing underlying disease. For these infants, management should be directed at the underlying cause and at identifying and preventing severe, life-threatening events.     

Hematological and blood viscosity changes in tail-suspended rats

BACKGROUND: Fluid shifts during exposure to microgravity result in a decrease in plasma volume which can lead to a transient increase in hematocrit. This transient increase in hematocrit could result in an increased blood viscosity. Yet, hematocrit returns to near normal values within a matter of hours of microgravity exposure as a result of a reduction in red blood cell mass. Rat tail-suspension models mimic the fluid shifts and hematological changes associated with microgravity exposure. METHODS: Tail-suspended rats were monitored for hematological and hemorheological changes over 4, 24, 72, and 168 h of tail suspension. Additionally, hematological and hemorheological changes were followed during recovery periods of 48, 120, and 192 h following 168 h of tail suspension. RESULTS: Although hematocrit increased significantly by 4 h of suspension, blood viscosity did not differ from controls. However, blood viscosity was significantly greater in the 72-, 168-, and 168/48-h suspension groups relative to controls despite no significant differences in hematocrits between groups. Theoretical calculations of blood viscosity at hematocrits of 50 and 60% (values intended to mimic hematocrits that would occur if red blood cell mass did not decrease) show a significant increase relative to the blood viscosities determined for the actual hematocrits in the experimental groups. CONCLUSIONS: The lowering of hematocrit associated with spaceflight may substantially reduce blood viscosity and thereby maintain the hematocrit at an optimal level for oxygen delivery to tissues.     

Cytogenetic and molecular genetic analysis of tumorigenic human bronchial epithelial cells induced by radon alpha particles

To establish a cell culture model for lung carcinogenesis, independent populations of the human papillomavirus 18-immortalized human bronchial epithelial cell line BEP2D were treated with high linear energy transfer radon-simulated alpha-particles, expanded and xenotransplanted into Nu/Nu mice. Six independent cell lines were established from tumors that developed from three separate radiation treatments as follows: treatment (Tx) 1 (30 cGy--two doses), H2BT, Tx 2 (30 cGy-- single dose), R30T1L, R30T2 and R30T3L, Tx 3 (30 cGy--single dose), H1ATN and H1ATBA1. Cytogenetic analysis revealed common changes in all tumor lines: loss of the Y chromosome (ch), one of three copies of ch8, one of three copies of ch14, and one of two copies of ch4p16-pter and ch11p15-pter. Analysis of polymerase chain reaction-amplified short tandem repeats of informative loci confirmed the loss of chY in all lines and loss of heterozygosity (LOH) at eight loci spanning the length of ch8 in all lines from Tx's 1 and 2. Our data support previous studies indicating the presence of tumor suppressor genes on ch8. LOH also was confirmed on ch14 at locus D14S306 in all cell lines from Tx 2 and in one of two lines from Tx 3. This region, 14q12-q13, may contain changes in one of the five known somatostatin receptor genes (SSTR1). No LOH was detected at any of the informative loci tested for on ch4 or ch11.