Heterogenous expression of nestin in human pancreatic tissue precludes its use as an islet precursor marker

The discovery of a pancreatic adult stem cell would have significant implications for cell-based replacement therapies for type 1 diabetes mellitus. Nestin, a marker for neural precursor cells, has been suggested as a possible marker for islet progenitor cells. We have characterized the expression and localization of nestin in both the intact human pancreas and clinical human pancreatic islet grafts. Nestin was found to be expressed at different levels in the acinar component of human pancreatic biopsies depending on donor, as well as in ductal structures and islets to some degree. In islets, insulin-producing beta-cells rarely co-expressed the protein, and in the ducts a small percentage (1-2%) of cells co-expressed nestin and cytokeratin 19 (CK19) while most expressed only CK19 (90%) or nestin (5-10%) alone. Assessment of nestin expression in neonatal pancreatic sections revealed an increased number of islet-associated positive cells as compared with adult islets. Nestin immunoreactivity was also found in cells of the pancreatic vasculature and mesenchyme as evidenced by co-localization with smooth muscle actin and vimentin. Samples from post-islet isolation clinical islet grafts revealed a pronounced heterogeneity in the proportion of nestin-positive cells (<1-72%). Co-localization studies in these grafts showed that nestin is not co-expressed in endocrine cells and rarely (<5%) with cytokeratin-positive ductal cells. However, relatively high levels of co-expression were found with acinar cells and cells expressing the mesenchymal marker vimentin. In conclusion we have shown a diffuse and variable expression of nestin in human pancreas that may be due to a number of different processes, including post-mortem tissue remodeling and cellular differentiation. For this reason nestin may not be a suitable marker solely for the identification of endocrine precursor cells in the pancreas.

Home health care referrals following hospital discharge: communication in health services delivery

Interinstitutional communication in the delivery of health services is fundamental to continuity of patient care. The purpose of this investigation was to describe the information transferred in the formal home care referral of elderly clients by hospitals and to describe selected organizational and medical condition characteristics that may affect referral content. Results indicated that approximately half of the information recommended by the literature was actually transmitted in the referral form. This information was composed primarily of background and medical data with some nursing care and almost no psychosocial data. More data were transferred when standardized written forms were used, when smaller hospitals provided the information, and when the home health agency was affiliated with the hospital.

Deep vein thrombosis following posterior lumbar spinal surgery

Deep vein thrombosis and pulmonary embolus are known complications of orthopaedic procedures, par- ticularly about the hip and knee. Spinal surgery has been associated with few thrombotic complications historically. Widespread use of instrumentation in adult patients has lead to a rise in complexity of adult spinal surgery. Length of operative procedures, level of difficulty, and bulk of instrumentation have all in- creased. We have noted an occasional pulmonary embolus in our center, as well as a small incidence of pul- monary embolus in recent reports of adult spine instrumented cases. A consensus conference through the National Institute of Health has estimated that between 300,000and 600,000hospitalized patients develop deep vein thrombosis each year with as many as 50,000 deaths per year occurring secondary to pulmonary embo- Ius.The incidence of thromboembolic disease appears to increase with age as well as with immobilization.' Prolonged rest and prone positioning on frames with compression of femoral veins and iliac veins have been indicated as possible risk factors during spinal surgery.

The peer review process: the art of judgment

Peer review is an essential mechanism for evaluating the judgment and performance of clinical providers. Reasons for conducting physician peer review range from identified quality-of-care concerns to general education. There are a variety of challenges to conducting an effective peer review, including the personal concerns of the peers conducting the reviews. This article reviews the potential uses of physician peer review, its basic methodologies, and challenges to and suggestions for obtaining effective peer review.

An assessment of discharge planning models: communication in referrals for home care

A home care referral generated upon hospital discharge communicates essential patient care information, links service providers, and facilitates continuity of patient care. The literature however, reveals that communication efforts are often inadequate and may even fail in this system. The purpose of this research was to examine whether various discharge planning models employed by hospitals resulted in differences in the quantity and quality of communication about patients referred for home health care. Kelly and McClelland's (1985) typology of discharge planning models provided the framework for the study. Using instruments designed specifically for this project, six referring hospitals' functional discharge planning models were labeled and 300 closed home care records of referrals were reviewed to ascertain the amount and type of data transmitted. Results indicated that only slightly more than half of the data recommended by the literature was actually transferred and that data was primarily background in nature. The hospital discharge planning model did make a significant difference in the amount and type of data shared, with liaison nurses sending the greatest amount of data. However, both conceptually and in practice, the discharge planning models simply describe an allocation of responsibility among various health personnel. They are not operational models in the traditional sense.