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Biomedical subjects

L Long

Publications and source records attributed to L Long.

At least 91 records · Page 5Linked to original sources

A first-year medical school pilot program for early clinical exposure.

A weekly out-patient elective in a medical oncology clinic was established for first- and some second-year medical students. Interviews were carried out immediately after the elective experience and two years later to evaluate the degree of success in achieving specific goals in this elective. Such clinical experience appeared to introduce the medical students to some of the major medical and psychosocial issues involved in the clinical care of patients, to be highly motivating for the students with regard to their standard concurrent basic science curriculum, and to relieve the impatience that first-year medical students have for clinical exposure. The usefulness of the elective, as perceived by the participating students, appeared to increase from the first to the second interview, that is as the students entered the clinical teaching program. The clinical setting was perceived by the students as more useful than either their increased understanding of medicine or observation of physicians as role models. The students' perception and understanding of physician-patient communication, and of the problems facing an oncology patient, appeared to be more favorably influenced than increasing confidence in the ability of the student to deal with patient interaction. Thus, a clinical oncology out-patient experience for first-year medical students appears to be sufficiently rewarding to justify the time and effort to develop such an elective.

Clinical Medicine↗

Fusion of Newcastle disease virus with liposomes: role of the lipid composition of liposomes.

We demonstrate here that fusion occurs between the membrane of the Newcastle disease virus (NDV) and liposomes. Fluorescence dequenching studies (using Rhodamine-bearing viral envelopes) revealed the mixing of the lipids constituting the viral and liposomal membrane. The digestion of internal viral proteins by trypsin-containing liposomes indicated the mixing of the internal aqueous compartments. This last assay is independent of exchange of lipids between liposomal and viral membrane in the absence of fusion. Investigation of the effects of liposomal composition indicated that the presence of phosphatidylethanolamine and gangliosides are essential to optimize fusion. The fact that the Newcastle disease virus membrane can fuse with liposome also confirms that fusion must be determined by the viral proteins and could be mostly independent of the nature or presence of the host proteins.

Cholesterol↗

Antigenic and biological characterization of avian paramyxovirus type 1 isolates from pigeons.

21 A/PMV-1 viruses were isolated from pigeons and characterized using polyclonal and monoclonal antisera in hemagglutination inhibition, seroneutralization and immunoprecipitation studies. Polyclonal and monoclonal antibodies directed against the HN and F proteins of Italien virus reacted with all pigeon isolates showing a close relationship between chicken velogenic and pigeon viruses. Differences in the M.W. of F0, P and M proteins were however observed between pigeon and chicken Italien virus. Marked differences in virulence were recorded among pigeon isolates; these were reflected by great variation in the IVPI of the different strains.

Animals↗

Monoclonal antibodies to hemagglutinin-neuraminidase and fusion glycoproteins of Newcastle disease virus: relationship between glycosylation and reactivity.

Eighteen hybridoma lines obtained by immunization of mice with Newcastle disease virus (NDV) lentogenic strain La Sota or velogenic strain Italien produced hemagglutinating monoclonal antibodies. The 18 monoclones were divided into four groups according to their reactivity toward native hemagglutinin neuraminidase protein (HN), nonglycosylated HN precursor, and heat-denatured HN blotted on nitrocellulose membranes. Only group II reagents were reactive toward their targets in all conditions tested. They were considered sequence-specific antibodies. Group I antibodies did not require glycosylation but lacked reactivity towards the denatured glycosylated antigen. Monoclonal antibodies from group III recognized only the native HN. Group IV was made up of a single monoclone that lacked reactivity with NDV Italien but recognized the La Sota strain in hemagglutination inhibition and enzyme-linked immunosorbent assays. Five hybridoma lines produced monoclonal antibodies which neutralized viral infectivity but failed to inhibit hemagglutination. One monoclonal antibody obtained after immunization of mice with NDV La Sota showed a low neutralization index versus NDV Italien. Four monoclonal antibodies derived from mice immunized with NDV Italien showed higher neutralization indices towards this strain. Neither the denatured F protein nor its nonglycosylated precursor was reacted against by the five monoclonal antibodies.

Animals↗

Cardiomyopathies characterized by evidence of resistance to left ventricular inflow.

Restrictive cardiomyopathy characterized by evidence of left ventricular inflow obstruction was studied in four cases--one child and three adults. In three of the cases, including the child, there was pathologic evidence of hypertrophic cardiomyopathy with asymmetric septal hypertrophy. In the fourth case, no cardiac disease was identified as the anatomic basis for the inflow restriction. This latter case broadens the concept of restrictive cardiomyopathies.

Adult↗

Correlation of electrocardiographic and pathologic findings in healed myocardial infarction.

A correlative study in 50 cases of healed myocardial infarction compared the 12 lead electrocardiogram with pathologic observations. The electrocardiogram was interpreted according to established Minnesota codes with some modifications. The following conclusions were reached: (1) The electrocardiogram underestimates the extent of myocardial infarction. (2) When a healed myocardial infarct at a specific location is recognized with electrocardiographic criteria, it is likely that there are unrecognized infarcts involving other areas of the left ventricle. (3) Infarctions involving the lateral and inferobasal areas are frequently unrecognized. (4) The electrocardiogram is more likely to miss myocardial infarcts in patients with multiple, than in those with single, electrocardiographically diagnosed infarcts. (5) Apical myocardial infarction does not appear to have specific electrocardiographic findings, other than those related to general infarct localization by electrocardiogram, particularly in patients with anteroseptal or anterolateral infarction. (6) Abnormal Q waves, generally thought to indicate transmural myocardial infarction, are frequently found in subendocardial infarction. (7) The simplified electrocardiographic classification of myocardial infarct site (anteroseptal, inferior, anterolateral) used in this study is preferable to more detailed classifications previously suggested by others.

Adult↗