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J F Bertles

Publications and source records attributed to J F Bertles.

40 records · Page 3Linked to original sources
PubMed1968

The physical state of hemoglobin in sickle-cell anemia erythrocytes in vivo.

Venous blood removed anaerobically from patients with sickle-cell anemia was transferred immediately into fixative, thus precluding significant loss or gain of oxygen by the cells. Electron microscopy demonstrated an intraerythrocytic fibrillar fine structure similar to that described in prior studies on erythrocytes sickled by deoxygenation in vitro. Observations reported here lead to these conclusions: (a) explanations of the sickling process derived from in vitro experimentation may with validity be applied to sickling in vivo; and (b) the term "sickled" must be used with caution: a sickle-shaped membrane does not necessarily endose Hb S in filamentous form.

Anemia, Sickle Cell↗
PubMed1968

Disproportional synthesis of the adult duck's two hemoglobins during acute anemia.

Concurrent synthesis of two or more hemoglobins occurs in normal man, the human hemoglobinopathies, and certain animal species. Duck erythrocytes produced in response to acutely induced anemic hypoxia (hemolysis or blood loss) contained reciprocally altered proportions of Hb I (alpha(2) (I) beta(2) (I)) and Hb II (alpha(2) (II) beta(2) (II)); the relative proportion of Hb II was 50-100% increased. Relative rates of synthesis of the two hemoglobins remained proportional to their new concentrations throughout erythroid maturation. This information favors the proposal that relatively increased activity, not delayed decay, of biosynthetic processes responsible for net synthesis of Hb II had occurred. These studies support the concept that the individual biosyntheses of multiple hemoglobins, presumably under genetic control, are potentially manipulable, and they provide evidence for one mechanism leading in a reproducible fashion to alterations in net synthesis in vivo.

Acetates↗
PubMed1968

Irreversibly sickled erythrocytes: a consequence of the heterogeneous distribution of hemoglobin types in sickle-cell anemia.

THE AMOUNT OF FETAL HEMOGLOBIN (HB F) IN ERYTHROCYTES OF PATIENTS WITH SICKLE CELL ANEMIA (HB SS DISEASE) WAS MEASURED BY TWO METHODS: (a) photometry of individual cells stained for Hb F by the Kleihauer-Betke technique; and (b) chemical assay of alkali-resistant hemoglobin in cells distributed according to specific gravity by ultracentrifugation. Irreversibly sickled cells (ISC), which could be identified directly during photometry and which were found to gather in high concentration at the bottom of ultracentrifuged cell columns, contained significantly less Hb F than non-ISC. Cell content of total Hb was constant regardless of cell size, shape, or ultracentrifugal behavior: thus absolute amounts of Hb F and S varied reciprocally from cell to cell. In experiments designed to estimate age, at formation, and rate of destruction of ISC, Hb SS blood was incubated with selenomethionine-(75)Se (which labels reticulocytes) or (51)Cr (which labels erythrocytes at random) and reinfused. Sequential blood samples were separated by ultracentrifugation into fractions rich in reticulocytes, non-ISC, and ISC; and chronological changes in the specific activity of each fraction were determined. Analogous information was obtained from radioautography of sequential blood samples after reinfusion of whole blood labeled with amino acids-(3)H: this technique permitted direct visual characterization of labeled erythrocytes as ISC or non-ISC, all of which had been reticulocytes at the time of reinfusion. The transformation of non-ISC into ISC, presumably a manifestation of membrane damage, proved to begin soon after cell release from the marrow; and ISC subsequently underwent rapid removal from the circulating blood. IT IS THEREFORE APPARENT FROM THESE STUDIES THAT, IN HB SS DISEASE, RELATIVELY SMALL RECIPROCAL CHANGES IN THE AMOUNTS OF THE TWO MAJOR HEMOGLOBINS CARRY PREDICTIVE IMPORTANCE: (a) net synthesis of Hb F is least in erythroid cells destined to become ISC; and (b) these irreversibly deformed erythrocytes suffer preferential destruction.

Adult↗