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Biomedical subjects

C Ernst

Publications and source records attributed to C Ernst.

At least 91 records · Page 5Linked to original sources
PubMed1979

Polycythemia vera. Increased expression of normal committed granulocytic stem cells in vitro after exposure of marrow to tritiated thymidine.

In previous studies of two patients with polycythemia vera (PV) and heterozygous at the X-linked locus for glucose-6-phosphate dehydrogenase (G-6-PD), only type A isoenzyme was found in non-lymphoid hematopoietic cells. However, some granulocytic and erythrocytic colonies grown in vitro had type B G-6-PD and therefore arose from presumably normal progenitors. In this study we exposed marrow cells from these same two patients to high-specific activity tritiated thymidine (3HTdR) before culture to kill cells actively synthesizing DNA. Individual granulocytic colonies were plucked and tested for G-6-PD after 14 d of culture. The frequency of type B colonies rose after exposure to 3HTdR from 8/101 to 11/36 in patient 1 and from 0/32 to 6/31 in patient 2 (P less than 0.003). No increase in the frequency of normal erythroid bursts after 3HTdR exposure was seen, implying that in PV, early granulopoiesis, and erythropoiesis are regulated differently. The results demonstrated that only type A granulocytic colonies, arising from the abnormal clone, were removed by the 3HTdR. In addition, for patient 2, statistical analysis indicated there was an absolute increase in normal granulocytic colonies detected in culture. Thus, PV clonal colony-forming units in culture (CFU-C) cycle more rapidly than do normal CFU-C and may suppress proliferation of normal CFU-C in vitro.

Cell Division↗
PubMed1979

Unicellular or multicellular origin of human granulocyte-macrophage colonies in vitro.

The assumption that human granulocyte-macrophage colonies have a unicellular origin and thus are true clones has been directly tested. Cells from seven females heterozygous for the common glucose-6-phosphate dehydrogenase (G-6-PD) gene (GdB) and the variant GdA were cultured in semisolid medium for granulocyte-macrophage colony growth and the enzyme type of individual colonies was determined. When the colony density was less than 20/dish, more than 95% of colonies had either type A or type B G-6-PD, but not both. At colony densities greater than 30/dish, between 15% and 75% of colonies had both enzyme types and therefore arose from more than one cell. These results are consistent with a unicellular origin for the colonies only when they are cultured at low densities. With increasing colony density, there was a greater frequency of colonies with both type A and type B activity, suggesting that accurate enumeration of committed stem cells can only be performed at low colony concentrations.

Blood Protein Electrophoresis↗
PubMed1976

The stability of ten antibiotics in artificial tear solutions.

We determined the relative potencies of penicillin G, carbenicillin, oxacillin, cephalothin, cephaloridine, gentamicin, kanamycin, neomycin, vancomycin, and bacitracin after their addition to three commercially available 0.5% hydroxypropyl methylcellulose artificial tear solutions in plastic squeeze bottles. We found no significant loss of antibiotic activity at room temperature over a period of seven days for all antibiotics except penicillin G, cephalothin, and cephaloridine. Three of the antibiotics were insoluble in one or more of the artificial tear solutions.

Anti-Bacterial Agents↗
PubMed1975

[The fate of elderly patients who have been refused admission. Half-yearly catamnesis of patients not admitted to a psychiatric clinic because of lack of space in 1973].

Six months after being refused admission to the psychiatric clinic, more than half of 128 patients over 60 years of age were found to be inadequately cared for in hospitals, homes and their families. Some were living in appalling conditions. Those admitted to other hospitals stayed there much longer than would be expected from the average hospital stay of psychiatric patients. Had these patients been admitted, the psychiatric clinic would very soon have been unable to admit emergency cases. This situation could be improved by providing better outpatient facilities, increased psychiatric supervision in homes for the elderly and more psychiatric day hospitals and homes. In this way psychiatric clinics could remain available for emergencies.

Aged↗