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Biomedical subjects

L Scott

Publications and source records attributed to L Scott.

At least 505 records · Page 28Linked to original sources

Interaction of aortic endothelial and smooth muscle cells in culture. Effect on glycosaminoglycan levels.

Co-cultivation of various intra- and interspecific combinations of pig and rat aortic endothelial cells (AEC) and smooth muscle cells (SMC) resulted in a marked increase in hyaluronic acid (HA) levels, a smaller but significant increase in sulphated glycosaminoglycans (GAG), and an increase in the HA/sulphated GAG ratio, compared with the separate culture of the two cell types. Culture of SMC in AEC-conditioned medium produced similar changes in GAG levels whereas SMC-conditioned medium had no effect on AEC GAG levels. These results add further support for the concept that epithelial cells in general can modulate the GAG composition of adjacent connective tissue and thereby influence its morphological and physiological properties. It is suggested that the normal amounts, types and distribution of GAG in the arterial wall, and especially in the intima, may be partly dependent on interaction between the endothelium and SMC. It is further suggested that injury to endothelium, with a consequent failure in this interaction, could lead directly to changes in intimal GAG composition that contribute to lesion development.

Animals↗

Gastrointestinal transit: the effect of the menstrual cycle.

Gastrointestinal transit time as well as serum estradiol and progesterone levels were measured in 15 normally menstruating women twice during their menstrual cycle, once in the follicular phase (days 8-10) when progesterone levels are low and once in the luteal phase (days 18-20) when progesterone levels are increased. Each subject had a progesterone rise during the luteal phase and onset of menses at the expected time documenting ovulatory cycles. Gastrointestinal transit time from ingestion of lactulose to the delivery of the disaccharide to the cecum was determined by monitoring breath hydrogen levels at 10-min intervals. Gastrointestinal transit time was significantly (p less than 0.01) prolonged in the luteal phase when progesterone levels were increased compared with the follicular phase. This study demonstrates that the menstrual cycle plays an important role in determining the gastrointestinal transit time in normally menstruating women.

Adult↗

Modification by suppressor cells and serum factors of the cell-mediated immune response in experimental pyelonephritis.

A marked suppression of the thymusderived (T)-lymphocyte response to concanavalin A has been demonstrated in vitro during renal infection. Suppression of the T-lymphocyte response in vitro was seen as early as 2 h after the induction of renal infection, but maximum suppression was found 24-72 h later. A population of suppressor cells in the splenic lymphocyte population, generated during the host's response to infection, contributed to the depressed lymphocyte response. Removal of suppressor cells restored the mitogenic responsiveness of the remaining splenic lymphocytes. Conversely, in co-culture experiments, a suppressor cell present in the splenic lymphocyte population of pyelonephritic animals was shown to be capable of suppressing the mitogenic responsiveness of normal splenic lymphocytes. Significantly reduced host vs. graft responses by the pyelonephritic animals confirmed, in vivo, the depression of cell-mediated immune mechanisms. An additional suppressive factor was found in the serum of pyelonephritic animals which depressed in vitro the mitogenic responsiveness of splenic lymphocytes from normal animals. Support for the suppressive role of this serum factor was found when splenic lymphocytes from pyelonephritic animals were tested in vivo in the absence of homolgous serum (graft vs. host). Under these conditions, the lymphocytes showed an enhanced reaction compared with lymphocytes from normal animals. The presence of a suppressor cell population and a serum factor, both capable of depressing cell-mediated mechanisms, may be major factors contributing to the establishment of infection in the kidney.

Animals↗

Ethics rounds in a Children's Medical Center: evaluation of a hospital-based program for continuing education in medical ethics.

Clinical rounds in medical ethics were established in 1971 in a large medical center to provide a forum for the multidisciplinary discussion of moral dilemmas in health care. The rounds consisted of case presentations and analyses by professionals primarily from the fields of law, pediatrics, religion, and philosophy. Five years of experience with these rounds were reviewed. Certain predominant themes emerged from the discussions. The most common involved the process of selecting a decision-maker. The rounds were elevated with regard to their impact and educational value. Although these sessions often did not lead to diametric change in position by participants, they did help to sensitize participants and to clarify and expose critical issues. Ethics rounds may offer a constructive response to the current outcry for more stringent consideration of moral values in hospital settings.

Adult↗

Diagnostic parameters in experimental renal infection.

Urinary tract infections are commonly encountered in medical practice but their laboratory diagnosis presents many difficulties. In this study we have used experimental models to assess the value of serum antibody, urinary antibody, rheumatoid factor, and the histochemical examination of renal tissue as diagnostic parameters. Under the conditions of the experiment the analyses did provide useful diagnostic information and may prove to be of value in the management of urinary tract infection in man.

Animals↗

Depression of the T-lymphocyte response to phytohaemagglutinin by renal cells.

The lymphocytic infiltrate in the renal parenchyma is a consistent histological feature of pyelonephritis, but the role of the lymphocytes in the immunobiology of pyelonephritis is not known. In this investigation the influence of the local environment on the potential function of T lymphocytes in the kidney was investigated. The experiments have demonstrated that the response of rat lymphocytes to stimulation in vitro with phytohaemagglutinin (PHA) can be entirely ablated by normal kidney cells. Even when the number of kidney cells added to cultures of lymphocytes was less than 2% of the cells present some ablation of T-lymphocyte function could be detected. The biological characteristics of the factor causing ablation of the PHA responsiveness of T lymphocytes were partially characterized and the factor appears to have unique features that differentiate it from lymphocyte chalones and other tissue factors influencing lymphocyte function. The results may explain recent findings where T lymphocytes were found to be the predominant lymphocyte in the inflammatory infiltrate but were not responsive to PHA in vitro.

Animals↗

Evidence that the platelet retention factor is separate from the factor VIII-related antigen and factor VIII.

Plasmas from a pregnant patient with von Willebrand's disease and from a patient with von Willebrand's disease who is taking Premarin had elevated levels of Factor VIII-related antigen and Factor VIII activity without any improvement in their platelet retention abnormality. When these were added to the blood from nonpregnant patients with von Willebrand's disease no significant improvement in platelet retention followed. This suggests that the "retention factor" is independent of the antigenic Factor VIII-like material.

Blood Coagulation↗

Pre-med panic.

Explore the source record for details and available documents.

Fear↗

Laboratory measurements of nutritional status as correlates of atrophic glossitis.

OBJECTIVE: To perform a comprehensive laboratory assessment of nutritional status in two elderly patients selected for the presence of atrophic glossitis, a classic physical sign of malnutrition. DESIGN: Case report. SETTING: Inpatient internal medicine ward at the William S. Middleton Memorial Veterans Medical Center, Madison, Wisconsin. MEASUREMENTS AND MAIN RESULTS: Blood specimens were analyzed by the Nutrition Evaluation Laboratory at the USDA Human Nutrition Research Center on Aging at Tufts University. Both subjects had biochemical evidence of protein-calorie malnutrition and were deficient or marginally deficient in several vitamins and trace minerals. CONCLUSIONS: Much work needs to be done to determine the sensitivity and positive predictive value of the classic physical signs of malnutrition as predictors of low biochemical levels and adverse clinical outcomes. The presence of atrophic glossitis should prompt the clinician to consider a basic nutritional assessment.

Aged↗