Influence of age and magnesium on calcium metabolism in rats

This study evaluates the effect of dietary magnesium concentration on calcium metabolism in rats of differing ages. Young (3 wk) and old (18 mo) Fischer 344 rats were fed the AIN-76A diet modified to contain either low (218 mg/kg) or adequate (419 mg/kg) Mg for 4 wk. Some rats subsequently underwent a metabolic balance study (12 d duration). Other rats were gavaged with approximately 220 KBq (6 microCi) of 47Ca; daily fecal and urine collections were made and periodic whole body radioactivity determined. Femurs were removed and analyzed. Calcium retention and balance were not affected by Mg in young rats. In old rats low Mg intake increased apparent Ca balance. Young rats retained about 3.25 times more of the original dose of 47Ca than did old rats. Young rats retained more 47Ca in the femur than did old rats; Mg intake had little effect. Aging accelerated Ca turnover rate, and whole body retention data suggest that adequate Mg does not significantly reduce Ca turnover.     

Fluorophore-conjugated anti-CEA Antibody for the Intraoperative Imaging of Pancreatic and Colorectal Cancer

Introduction  Colorectal and pancreatic cancers together comprise the third and fourth most common causes of cancer-related death in the United States. In both of these cancers, complete detection of primary and metastatic lesions at the time of surgery is critical to optimal surgical resection and appropriate patient treatment. Materials and Methods  We have investigated the use of fluorophore-labeled anti-carcinoembryonic antigen (CEA) monoclonal antibody to aid in cancer visualization in nude mouse models of human colorectal and pancreatic cancer. Anti-CEA was conjugated with a green fluorophore. Subcutaneous, orthotopic primary and metastatic human pancreatic and colorectal tumors were easily visualized with fluorescence imaging after administration of conjugated anti-CEA. The fluorescence signal was detectable 30 min after systemic antibody delivery and remained present for 2 weeks, with minimal in vivo photobleaching after exposure to standard operating room lighting. Tumor resection techniques revealed improved ability to resect labeled tumor tissue under fluorescence guidance. Comparison of two different fluorophores revealed differences in dose–response and photobleaching in vivo. Conclusion  These results indicate that fluorophore-labeled anti-CEA offers a novel intraoperative imaging technique for enhanced visualization of tumors in colorectal and pancreatic cancer when CEA expression is present, and that the choice of fluorophore significantly affects the signal intensity in the labeled tumor. These data were presented at the Society for Surgery of the Alimentary Tract meeting as part of the Digestive Diseases Week, San Diego CA, May 21 2008. Sharmeela Kaushal and Michele K. McElroy shared authorship. Work supported in part by: Cancer Therapeutics Training Program (T32 CA121938) National Institutes of Health (CA109949-03) American Cancer Society (RSG-05-037-01-CCE).     

Mechanisms of phosphatidylcholine acyl remodeling by human fetal lung

The molecular specificity of phosphatidylcholine (PC) synthesis by the de novo pathway in postmortem samples of human fetal lung (15 to 20 wk of gestation) was determined from the incorporation pattern in isolated microsomal preparations of CDP:[14C]choline into individual molecular species of PC. These analyses are based on the assumption that the molecular species composition of the pool of endogenous diacylglycerol used for PC synthesis by isolated microsomes reflects that of the authentic pool of diacylglycerol converted to PC by intact cells. Comparison of this microsomal incorporation pattern of radiolabel into PC with tissue PC composition suggested that even at this early stage of gestation 50% of lung dipalmitoyl PC was derived from synthesis de novo, with the remainder coming from acyl remodeling mechanisms. Analysis of PC synthesis de novo by organ cultures of human fetal lung showed that these acyl remodeling mechanisms were lost in culture. Despite evidence for differentiation of type II alveolar epithelial cells in culture, equilibrium labeling of PC with [14C]choline over 18 h resulted in a progressive decline in fractional incorporation into dipalmitoyl PC with time in culture. By 4 days in culture, this value was no different from the fractional incorporation of CDP:[14C]choline into microsomal PC in vitro over 3 h. The pattern of PC synthesized was not altered when total PC synthesis was stimulated by exposure of cultures to dexamethasone and tri-iodothyronine but was readily manipulated by exposure to exogenous fatty acids. These results demonstrate for the first time the activity of PC acyl remodeling mechanisms in human fetal lung, well before the initiation of surfactant production.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardio-pulmonary exercise testing in the evaluation of mitral and aortic valve incompetence

Cardio-pulmonary exercise (CPX) testing can be used to discern the functional integrity of the right and left heart and pulmonary circulation in patients with chronic mitral or aortic valvular incompetence. The noninvasive determination of VO2 max and anaerobic threshold in these patients serves to assess the severity of chronic circulatory failure and to predict the maximum exercise cardiac output (or cardiac reserve). Invasive monitoring of right heart pressures and left ventricular filling (wedge) pressure identifies abnormalities in ventricular function and the pulmonary circulation that may not be otherwise apparent. Noninvasive and invasive CPX testing is therefore a valuable tool which can also be applied to the serial evaluation of these patients. CPX offers several advantages over traditional indices of ventricular function (e.g., resting cardiac output, filling pressure and ejection fraction) in that it objectively identifies the patients functional status, the heart's pumping reserve, and the integrity of the cardio-pulmonary unit. The utility of CPX, however, in assessing an early and subtle decline in left ventricular function and its ability to predict the appropriate timing for valve replacement in chronic mitral or aortic valvular incompetence remains to be elucidated.     

Applying technology today. A computerized nursing recruitment database

This article describes the development and implementation of a computerized nursing recruitment program. This system offers a fast, efficient, individualized, item-selectable mechanism for tracking and monitoring recruiting activities. Included in this system are easily accessible functions that provide precise information regarding the activities and costs relating to recruitment transactions. It is user-focused and coded for accurate storage and retrieval of information. This program has multiple implications for improving or revising recruitment activities. Nursing administrators can obtain detailed reports of the operations of the recruiting office, and internal audits can be easily generated to identify areas of efficiency as well as areas needing revision. It is written to be integrated with other management systems, thus providing a rapid and comprehensive network of communication that is cost-effective and precise.