Search PubMed⌕ Search

Biomedical subjects

C W Jackson

Publications and source records attributed to C W Jackson.

At least 127 records · Page 7Linked to original sources

Placental transfer of tritium-labelled prostaglandin A1 in the rat.

Pregnant Long Evans rats were treated with 25 muCi 3 H-prostaglandin A1 on either gestational day 15, 18 or 21. The highest concentrations of radioactivity were found in maternal kidneys, lungs and liver. The levels of radioactivity in the gut and also in amniotic fluid markedly increased with time after isotope administration. Significant levels of radioactivity were present in fetal tissues and in the placenta.

Animals↗

Platelet recovery after induction of acute thrombocytopenia.

After mild thrombocytopenia (about 50-100% of control platelet level), induced by injection of antiplatelet serum (APS), platelets increased at a fairly constant and moderate rate for about 4 days and reached a maximum count, greater than pretreatment levels, on the fifth day. After moderate to severe thrombocytopenia, an early moderate rate of platelet increase was succeeded within 2 days by a second more rapid rate that persisted for about 3 days. The maximum overshoot of the platelet count was usually less than twice the pretreatment level. After the largest doses of APS, the platelet count remained depressed for several days. Platelet response after acute thrombocytopenia induced with antiserum is therefore variable, depending on the level and duration of thrombocytopenia.

Acute Disease↗

Thrombopoietin level in young patients is related to megakaryocyte frequency and platelet count.

PURPOSE: To examine the relationships among platelet counts, bone marrow megakaryocyte frequency, and circulating thrombopoietin (TPO) levels. PATIENTS AND METHODS: TPO levels in 17 children and one young adult with chronic or recurrent thrombocytopenia were measured by ELISA and megakaryocyte frequency was analyzed by light microscopy. Three groups of patients were studied: Group I patients had aplastic anemia and absent or decreased megakaryocytes; Group II patients had intermittent periods of chemotherapy-induced thrombocytopenia; and Group III patients had normal or increased megakaryocytes. Controls consisted of 77 healthy adults. RESULTS: Patients in Group I had markedly increased TPO levels compared to normal controls. Their levels were significantly different (p = 0.03) from those of patients in Group III. The latter had normal or only mildly increased TPO levels except for one patient with myelodysplastic syndrome. Patients in Group II had markedly elevated TPO levels. After their bone marrow and platelet counts recovered from chemotherapy, their TPO levels decreased. In all three groups, a transient increase in platelet count (e.g., after platelet transfusion or anti-D immune globulin therapy) was associated with a moderate decrease in TPO. CONCLUSIONS: From this study, three conclusions can be made: 1) TPO levels are inversely related to megakaryocyte frequency; 2) platelet counts have a modest influence on TPO level; and 3) TPO levels may have clinical utility in diagnosis and management and further our understanding of the pathobiology of the disorders that cause thrombocytopenia.

Adolescent↗