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Biomedical subjects

C Hershko

Publications and source records attributed to C Hershko.

At least 181 records · Page 10Linked to original sources
PubMed1977

Time-related increase in leucocyte yields by continuous-flow centrifugation (CFC) leukopheresis.

Continuous flow centrifugation leukopheresis lasting 3 to 4 h was performed 18 times on 16 normal donors. The total yield of leucocytes collected was 1.59 +/- 0.14 x 10(10) (mean +/- SE). Comparison of leucocyte yields on the first, second, third and fourth hour of leukopheresis indicated a progressive increase with time in 15 out of 18 procedures, with 3.6 times more leucocytes collected within the last hour of leukophoresis as compared to the first hour. This increase was independent of the volume of leucocytes collected per unit time, since an equally significant increase was found when calculated per 100 ml of leucocyte concentrate. Although the mechanism of this improvement in yield with time is unknown, the present data indicate, that moderate prolongation of the duration of leukopheresis may result in an increase in efficiency which is comparable to that produced by the use of hydroxyethyl starch, etiocholanolone or corticosteroids.

Blood Transfusion↗
PubMed1977

Ferritin synthesis in inflammation. I. Pathogenesis of impaired iron release.

Plasma iron turnover (PIT) and ferritin synthesis in the liver and spleen were studied in rats within the first 24 h of inflammation produced by turpentine injection. Comparison of the sequential changes in PIT and ferritin synthesis showed that alterations in ferritin synthesis preceded the changes in plasma iron exchange throughout the study. Thus, after 4 h inflammation ferritin synthesis was twice normal whereas plasma iron and PIT were still unchanged. Conversely, maximal reduction in plasma iron occurred after 12 h inflammation, at a time when ferritin synthesis had already declined to normal rates. These correlations seem to indicate that, in analogy with other acute phase reacting proteins, increased ferritin synthesis is a primary nonspecific response which is part of a general pattern of the systemic effects of inflammation. This increase in ferritin synthesis is assumed to be responsible for the diversion of labile iron into ferritin stores, and its reduced availability for release from tissues.

Animals↗
PubMed1977

Traumatic hemolysis after aortofemoral bypass. A study of 25 cases.

The prevalance of traumatic intravascular hemolysis was estimated in 25 patients following aortofemoral bypass. Stigmata of mild red cell fragmentation were noted in approximately one third of the patients, but in only one of them was hemolysis of sufficient severity to be of clinical significance. The case history and laboratory findings in this patient are described in detail. This study indicates that traumatic hemolysis should be considered as a possible cause of anemia developing after aortofemoral bypass.

Aged↗
PubMed1976

Iron mobilization in the pregnant rat.

Iron exchange in the pregnant rat was quantitated by repeated determinations of plasma iron turnover (PIT), transferrin iron distribution and measurements of storage iron and food iron utilization employing selective radio-iron probes. Despite a sixfold increase in PIT, intestinal absorption of iron accounted for 40% of the PIT throughout pregnancy, with variations not exceeding +/- 5%. Increased fetal requirements were efficiently compensated for by the mobilization of iron from maternal tissue stores and by increased absorption, and there was no subsequent reduction in iron supply to maternal tissues. Enhancement of iron absorption occurred in the absence of a reduction in serum iron levels or the size of iron stores. In view of the close correlation between PIT and rates of absorption it is postulated that iron absorption in the pregnant rat is regulated by PIT which in turn is determined by the rate of plasma iron clearance by the placenta and the maternal erythroid marrow.

Animals↗
PubMed1976

Relapsing haemolytic anaemia of pregnancy with negative antiglobulin reaction.

Four patients are described in whom seven episodes of haemolytic anaemia associated with pregnancy were observed during a follow-up period of 2 to 16 years. Normal haemoglobin levels were found both before and after pregnancy. Despite consistently negative antiglobulin tests, an autoimmune haemolytic mechanism is suggested by the rapid destruction of transfused blood, favourable response to corticosteroids and the development of transient haemolytic anaemia in three of the infants. In view of its unique clinical and laboratory features and relatively mild course, recognition of this condition as a distinct clinical entitity seems to be justified.

Adult↗
PubMed1976

The inhibitory effect of vitamin E on desferrioxamine-induced iron excretion in rats.

The influence of vitamin E on the mobilization and excretion of storage iron induced by DF was studied in normal and iron-overloaded rats. Vitamin E administration in pharmacologic doses resulted in complete inhibition of the effect of DF on storage iron in iron-overloaded rats while no such effect could be demonstrated in rats with normal iron stores. The mechanism of the observed inhibition of DF action by vitamin E is at present unknown. Nevertheless this drug interaction has to be considered in view of ongoing therapeutic trials where both antioxidants and iron chelating drugs are administered simultaneously to thalassemic patients with transfusion induced iron overload.

Animals↗
PubMed1975

Reversible central nervous system dysfunction in folate deficiency.

An epileptic patient on chronic anticonvulsant drug therapy is described, in whom anaemia and neurological abnormalities including progressive dementia, bilateral pyramidal tract signs, incontinence and ataxia developed. Vitamin B12 serum levels and absorption were normal, but serum folic acid levels were low. Both the neurological disturbances and anaemia resolved following oral folic acid administration. This sequence of events in our patient suggests a cause and effect relationship between the folate deficiency and the coexistent, transient neurological syndrome.

Aged↗
PubMed1975

Serum and erythrocyte folates in combined iron and folate deficiency.

A high incidence of iron and folate deficiency was found in 80 female subjects living in a private institution. Iron therapy in individuals with low serum iron values resulted in a significant increase in hemoglobin levels. An improvement in serum and RBC folate levels was also found following iron therapy but this could not be attributed to treatment since a similar increase was observed in untreated control subjects, probably due to an increased dietary intake of folates during the study period. In subsequent studies small amounts of pteroylglutamic acid were given to all patients and their response to therapy was related to initial serum and RBC folate values. No correlation between serum folate levels and response to folate therapy could be demonstrated. Red cell folate levels on the other hand correlated well with response to therapy. A significant increase in hemoglobin was found following folate therapy in patients with low RBC folates, but not increase in subjects with normal RBC folates. Conversely, the increase in hemoglobin following iron therapy in subjects with normal RBC folates was three times as much as in patients with low RBC folates. Thus, unlike serum folate determinations, RBC folate measurements are a reliable index of tissue folate stores, and useful in the prediction of response to folate therapy in both the iron-deficient and iron-replete states.

Adult↗
PubMed1975

Observations on the in vivo aging of red cells in the rat.

Aging of rat erythrocytes was studied in vivo by two experimental models. In the first, a single cohort of erythrocytes labelled with radioiron was followed; in the second, sequential hypertransfusions were employed to obtain a defined red cell population, which was continuously transferred from host to host. The results are compatible with a normal red cell life span of about 60 days and with sequestration of senescent erythrocytes in the spleen and in the liver. Red cell aging was associated with a decline in cell volume, haemoglobin, G6PD and ATP content. There were no measureable changes in osmotic fragility. Thus, changes in osmotic resistance do not appear to be critical factors limiting the life span of circulating erythrocytes in the rat.

Adenosine Triphosphate↗