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Biomedical subjects

H Kronenberg

Publications and source records attributed to H Kronenberg.

At least 163 records · Page 9Linked to original sources

Haemoglobin Camperdown beta104(G6) arginine leads to serine.

Routine investigation of ante natal patients revealed a subtle change in the electrophoretic pattern on cellulose acetate of the proposita. Further investigations by isoelectric focussing in polyacrylamide gel suggested the presence of two major haemoglobin components. Using a modified cellulose acetate technique globin chain separation revealed an abnormal beta-chain. Chain separation on a carboxymethyl-cellulose column provided a pure sample of the abnormal beta-chain. After amino-ethylation, tryptic digestion and peptide mapping, amino acid analysis of relevant peptides showed the abnormality in the beta-chain to be a substitution of arginine by serine at the 104 position. The presence of a positively charged residue at this position would appear to be necessary for the stabilization of the haemoglobin central cavity. The replacement by serine in this haemoglobin leads to slightly decreased stability but does not appear to affect the oxygen affinity.

Adult↗

Androgen-induced hepatoma.

Three cases of hepatocellular carcinoma are reported in young men who had been taking androgenic-anabolic steroids. The tumours were histologically similar to those described in previous reports. The tumour progressed slowly in two patients during four and seven years of observation, but in the latter bony metastases occurred. In two patients the tumours regressed after administration of the drug was discontinued. These cases strengthen the evidence that exogenous androgenic-anabolic steroids may produce liver tumours. The use of these drugs should be confined to serious conditions in which they are known to be effective. Biochemical tests of liver function and serum alphs-fetoprotein estimation are not useful as screening-tests for hepatoma in patients taking androgens, and regular isotopic liver-scanning is recommended.

Adult↗

Fibrin powder turbidity measurement for rapid assessment of antiplasmins.

Fibrinolytic activity was determined from the rate of disappearance of turbidity in a suspension of heat-treated fibrin powder. Using this method for estimating residual fibrinolytic activity in mixtures of serum and plasmin, antiplasmin behaviors of specimens from patients with various clinical disorders were determined after long and short preincubation times. Slow-acting antiplasmins were found to be increased in a variety of conditions among these patients, while immediate acting antiplasmins were generally decreased, compared with those in specimens from a large pool of normal, healthy vounteers. Normal women taking oral contraceptives had consitently high levels of slow antiplasmins. Tests in vitro showed that the antifibrinolytic agents epsilon-aminocaproic acid, Trasylol and soybean trypsin inhibitor act only as fast antiplasmins.

Aminocaproates↗

The bone marrow colony forming cell in megaloblastic anaemia and iron deficiency anaemia.

Bone marrow samples from patients with megaloblastosis and iron deficiency have been assayed for their content of in vitro colony forming cells (CFC), and compared with a group of normal patients. The concentration of these cells was found to be significantly increased in the megaloblastic group, while their content in the iron deficient patients was slightly higher than the controls. An in vitro thymidine suicide procedures was utilised to assay the proportion of CFC in the S phase of the cycle. This was found to be increased in the megaloblastic group and only slightly increased in the iron deficient group. The findings in megaloblastosis seem to be consistent with the concept of impaired DNA synthesis. As the CFC monitors an early granulocytic progenitor these data suggest some impairment in DNA synthesis or an abnormal increase in amplification in this myeloid stem cell compartment. Such alterations in granulopoietic proliferation may contribute to the ineffective granulopoiesis of megaloblastosis and accordingly may be an important factor in the development of neutropenia sometimes associated with this condition. The slightly increased CFC concentration and altered cell cycle status found in iron deficiency suggest that iron is not a major requirement for granulopoiesis.

Anemia, Hypochromic↗

Cold agglutinin formation in patients undergoing haemodialysis. A possible relationship to dialyser re-use.

Cold agglutinins with anti-N characteristics were shown to develop in as short a time as four months in patients on home dialysis. It appeared that the development of such antibodies is related to dialyser re-use. Those who were treated without re-using their dialyser did not develop these antibodies. Anti-N may cause early graft failure associated with agglutination in a cold allograft. Moreover, if these antibodies develop in patients on dialysis there may be problems with extracorporeal dialysis and blood transfusion.

Agglutinins↗

Studies on phospholipids in the action of a lupus coagulation inhibitor.

Plasma from a patient with early manifestations of disseminated lupus erythematosus, a prolonged partial thromboplastin time with kaolin, mildly prolonged prothrombin time, and a circulating inhibitor affecting the assay of several clotting factors was investigated. The most sensitive test for the inhibitor was found to be the Russell viper venom time without phospholipid. A decrease in phospholipid concentration as well as decreased sodium chloride levels both significantly enhanced the effect of the inhibitor in several coagulation tests. Of various phospholipid substitutes tested phosphatidyl ethanolamine was the most effective in partially correcting for the inhibitor. The inhibitor was not localized to the patient's platelets, which were also found to partially neutralize its effect. Since lupus erythematosus is sometimes accompanied by thrombocytopenia the coagulation disorder may be aggravated by such a deficiency of phospholipid. The inhibitor appears to act by preventing binding of phospholipid to the Xa/V/thromboplastin complex. It was characterized as a gamma globulin of mixed class.

Adult↗