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Biomedical subjects

B Klein

Publications and source records attributed to B Klein.

At least 397 records · Page 22Linked to original sources
PubMed1976

Study of cell death in Friend leukaemia.

Cell death of splenic Friend leukaemic cells has been studied in vivo, using 125I-UdR and 3H-TdR pulse labelling. The evolution of the splenic specific activity has been measured by autoradiography and external counting during 40 hr after injection of the labelled precursor. These two techniques show the existence of a large reutilization of 3H-TdR (50%), which is measurable as soon as 7 hr after the injection. The DNA turnover rate is rapid, 83-8% of the splenic cellular DNA being renewed per day. Those results confirm that most of the cells produced in the Friend leukaemic spleen are rapidly lost; they also demonstrate that this cell loss is mainly due to a massive death, which occurs in proerythroblastic and erythroblastic compartments after one or two cell divisions. Friend leukaemic cells, which are characterized by a limited capacity of proliferation and a short lifespan, do not appear to be malignant.

Animals↗
PubMed1976

Fluorometry of plasma amino nitrogen, with use of fluorescamine.

We describe a fluorometric procedure, with use of fluorescamine, for determining plasma amino nitrogen in a 10-mul sample of deproteinized plasma. Values for apparently healthy human subjects agree well with those obtained by spectrophotometry. The simplicity and speed of the assay recommends it as a screening procedure for detecting aminoacidopathies.

Adult↗
PubMed1976

Physiopathology of human and virus-induced murine leukemias.

The authors describe a coherent model for differentiated leukemias derived from physiopathological studies on Friend leukemia. In Friend leukemia, Friend virus induces permanent differentiation of erythropoietin-responsive cells. This erythropoietic proliferation and maturation is accompanied by a marked cell loss and provokes enlargement of the stem cell compartment. The so-called leukemic cells have a limited proliferation capacity and may not be truly malignant as opposed to blastic cells in acute leukemias. Clinical, hematological, and physiopathological data that are presently available in chronic granulocytic leukemia, polycythemia vera, and the erythroblastic component of erythroleukemia are compatible with the Friend physiopathological model. It is suggested that these differentiated leukemias initiate from an uncontrolled differentiation of a committed cell compartment, which stimulates proliferation of the stem cell compartment. The disease would be due to a proliferation and accumulation of "subnormal" cells characterized by a shorter mean life-span than the normal differentiated cell population. Although limited, the data available suggest that the physiopathology of acute leukemias is clearly distinguishable from that of differentiated leukemias; several immunological and therapeutic applications of this model are outlined.

Animals↗
PubMed1975

Mathematical modelling of cell cycle and chronobiology: preliminary results.

A mathematical model taking into account the observed diurnal variations in cell kinetics is presented. The principle of the method is to divide each phase of the cell cycle in a definite number of compartments and to assume that the fluxes into and out of the compartments corresponding to the G1 phase are the only varying parameters through the day. Theoretical evolutions of percentages of cells in M and S phase, theoretical curves for percentage labelled mitosis experiment are derived. Preliminary results of the applications of the model to interpretation of published experimental data obtained in hamster cheek pouch epithelium are shown.

Cell Division↗
PubMed1975

A guide to differentiated developmental diagnosis with a case demonstrating its use.

The great influx of children needing assessment has presented all diagnosticians with a large body of patients whose conflicts are relatively unfamiliar ones. These children do not fit into the expectable pattern of normal development, nor is an adult-oriented frame of reference of much help in understanding them. What seems needed is a schema in which the developmental deficiencies of these children are related to their present functioning. This paper introduces a guide covering five aspects of development. The guide gives descriptions of normal functioning at ages 0 to 1 1/2, 1 1/2 to 3, 3 to 6, and 6 to 10, and also shows the persistence of this functioning as it is reflected in the attitudes, feelings, and behavior of primary school children. A case illustration is presented that demonstrates the use of the guide.

Adolescent↗
PubMed1975

Corneal arcus and cardiovascular disease in Evans County, Georgia.

The population of Evans County, Georgia was surveyed, during a cardiovascular disease study, for the prevalence of corneal arcus. Rates varied with race and sex and increased in prelalence with age in all groups. Arcus was positively correlated with serum cholesterol level. In white males, a significantly higher prevalence rate of coronary heart disease was found in those who had corneal arcues, but arcus was not correlated with subsequent coronary heart disease incidence in any race-sex group.

Adolescent↗
PubMed1975

Fluorometric serum lipase assay: evaluation of monodecanoyl fluorescein as substrate.

The elements of the mechanized fluorometric lipase (EC 3.1.1.3) assay of Fleisher and Schwartz [Clin. Chem. 17, 417 (1971)] were made optimum; a manual adaptation was also developed. Hydrolysis of the monodecanoyl fluorescein substrate by hog pancreatic lipase is a zero-order reaction. The hydrolytic activity of normal human serum, serum from hospitalized patients without pancreatitis, and serum from patients with acute pancreatitis showed considerable overlap. Bile salts, considered activators in titrimetric or turbidimetric lipase assays, inhibited hydrolysis of the substrate by human serum. We conclude that monodecanoyl fluorescein is not a specific substrate for the serum lipase measured in acute pancreatitis.

Acute Disease↗