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Biomedical subjects

H Kronenberg

Publications and source records attributed to H Kronenberg.

At least 127 records · Page 7Linked to original sources
PubMed1984

Chronic myeloid leukaemia presenting as femoral head necrosis.

A 17-year-old male whose initial presentation of chronic myeloid leukaemia (CML) was necrosis of the right femoral head is reported. This is the first case report to our knowledge of CML presenting with such a lesion and is of further interest in that almost all reported cases of destructive bony lesions in this disease have been associated with blast transformation. Our patient in contrast has remained in stable chronic phase for over 30 months.

Adolescent↗
PubMed1984

Haemoglobin D Punjab. Interaction with alpha thalassaemia and diagnosis by gene mapping.

A family which illustrates the inheritance of Hb D Punjab (a beta globin chain variant) and alpha thalassaemia is described. Interaction between Hb D Punjab and alpha thalassaemia is observed since levels of Hb D vary according to the number of alpha globin genes deleted. The technique of gene mapping has been utilised in the current study to provide definitive evidence of alpha thalassaemia and also demonstrates a novel way to identify Hb D Punjab.

Adult↗
PubMed1984

An evaluation of serum erythropoietin estimation by a hemagglutination inhibition assay in the differential diagnosis of polycythemia.

A commercially available hemagglutination inhibition assay kit for the measurement of erythropoietin (EPO) was evaluated for its usefulness in the differential diagnosis of the polycythemic states. Serum samples were obtained from patients with polycythemia rubra vera (active and controlled), secondary and relative polycythemia and from normal controls. Firstly, we found that the mean EPO level (+/- SD) of our normal controls (81 +/- 69 miu/ml) was higher than the manufacturer's quoted normal range (15-59 miu/ml) and that there was a significant spread of values (7-233 miu/ml). Secondly, within each patient subgroup studied, the spread of data points was so wide that interpretation of individual data points would be impossible. We conclude that this assay kit is of little value for serum EPO estimation and in the differential diagnosis of polycythemia.

Diagnosis, Differential↗
PubMed1984

Diagnosis of alpha thalassemia in the newborn. Cord blood survey utilizing gene mapping.

Application of the technique of gene mapping has made possible accurate assessment of the alpha thalassemia defect in cord blood samples obtained in a Sydney teaching hospital. Results showed a 5.2% incidence of the alpha+ thalassemia haplotype in the population being tested. Various hematological parameters such as hemoglobin, mean corpuscular hemoglobin, hemoglobin EPG pattern at pH 8.9 and the percentage of hemoglobin Bart's determined by elution at pH 6.7 were measured to assess which would be the most useful in diagnosis of alpha thalassemia at this time of life. The most consistent test proved to be hemoglobin EPG pattern at pH 8.9, and reasons for this are discussed.

Chromosome Mapping↗
PubMed1984

Identification of beta variant hemoglobins by DNA restriction endonuclease mapping.

An alternative method for identifying beta variant hemoglobins is described. Computer analysis of restriction sites was used to predict which beta variants could be detected by DNA mapping. 61 of 217 variants were shown to have changes in restriction fragment patterns which were useful markers for the abnormal hemoglobin. A further 25 could be identified by polyacrylamide electrophoresis. Implications of DNA analysis in diagnosis of variant hemoglobins are discussed.

Base Sequence↗
PubMed1983

Measurement of factor VIII CAg by immunoradiometric assay in human tissue extracts.

Samples of normal tissues taken from three patients within 24 hours of death were physically disrupted, washed and extracted. Centrifuged supernatants were tested for factor VIII coagulant antigen (VIII CAg) and factor VIII related antigen (VIII RAg) by radioimmunoassays using homologous and heterologous antisera respectively. VIII RAg was readily washed out by isotonic saline whereas VIII CAg required 1.5 M sodium chloride for optimal extraction from tissue homogenates. Highest levels of VIII CAg were detected in some lymph nodes followed by lung, liver and spleen. There was rapid loss of VIII CAg from most tissues in the absence of proteolytic inhibitors.

Antigens↗
PubMed1983

The use of peripheral blood feeder layers as a source of GM-CSF for human bone marrow cultures.

The use of peripheral blood feeder layers as a source of stimulus for colony formation by human granulocytic progenitor cells in semi-solid agar cell cultures was examined. Comparison with various conditioned media demonstrated that cultures stimulated by peripheral blood feeder layers produced the greatest number and largest colonies. The cell concentration in the feeder layers was more important than the total cell number. Feeder layer plates containing 2 X 10(5) cells at a concentration of 1 X 10(6) cells/ml proved to be just potent as the conventional feeder layer plates containing 1 x 10(6) cells/ml in 1 ml. Thus feeder layer plates can be more economical in terms of cell numbers than has previously been reported. By using a known panel of donors for the leukocytes, the number of sub-optimal batches of feeder layers was reduced. Addition of 1 microM adenosine 3':5'-cyclic-monophosphate or 10 micrograms/ml Li2CO3 to poor feeder layers enhanced their colony-stimulating ability.

Bone Marrow Cells↗
PubMed1983

Prediction of response to plasma exchange in chronic relapsing polyneuropathy. A clinico-pathological correlation.

The clinical features, results of nerve conduction studies and sural nerve biopsy findings have been compared in 5 patients with chronic relapsing polyneuropathy in whom plasma exchange was used in treatment. In 2 patients who consistently responded to plasma exchange, the dominant pathological findings was segmental demyelination without prominent onion bulb formation, whereas axonal degeneration was more prominent in the cases which did not respond. It is concluded that in cases of chronic relapsing polyneuritis where the clinical, electrophysiological and histological features suggest primary demyelination, plasma exchange may provide a useful adjunct to therapy.

Adult↗
PubMed1983

Aplastic anemia in association with gold therapy for rheumatoid arthritis.

Over a ten year period five patients developed aplastic anemia in association with gold therapy for rheumatoid arthritis. None of these patients was suitable for bone marrow transplantation due to the lack of a compatible sibling. Four patients with severe aplastic anemia died, despite intensive haemopoietic support and trials of gold chelating agents. Survival ranged from 22 to 103 days (mean 55 days) with death in each case being due to a combination of bleeding and infection. The remaining patient with moderate aplasia survived, recovering over a period of two to three years.

Adult↗
PubMed1983

An analysis of peripheral blood burst forming units-erythroid in the polycythaemic states.

Peripheral blood burst forming units-erythroid (BFU-E) were measured by the plasma clot cell culture technique in patients with the various subtypes of polycythaemia and compared to normal. 10 patients with active polycythaemia rubra vera (PRV) were found to have a mean BFU-E level of 48 +/- 15.8 (SEM) per 5 X 10(5) cultured cells which was significantly different from normals (4 +/- 1.1, P less than 0.02), patients with controlled PRV (7 +/- 1.6, P less than 0.025), secondary polycythaemia (1 +/- 0.3, P less than 0.015) and relative polycythaemia (0, P less than 0.015). Burst forming units were found to fall to normal levels in patients with PRV with appropriate disease control and then to rise again in patients untreated for more than 18 months. Clinical aspects. Measurement of BFU-E levels from the peripheral blood could provide a useful adjunct from an accessible source in the differential diagnosis of polycythaemia as well as being of use in serial monitoring of patients with PRV.

Bloodletting↗
PubMed1983

In vitro clonogenic assays in selective neutropenia.

Granulocyte-monocyte colony forming cell (GM-CFC) concentration and the proportion of GM-CFC in DNA synthesis (S) were determined in 43 patients with varying degrees of selective neutropenia, including 5 patients who were normal extremes (2.0-2.5 x 10(9) neutrophils/1), to study the diagnostic and prognostic significance of clonogenic assays and to determine the response of the committed myeloid stem cell to neutropenia. The proportion of GM-CFC in S proved to be a more useful parameter than the GM-CFC concentration. 75% of the patients with greater than 60% GM-CFC in S returned to normal within 1 month. Patients with less than 20% GM-CFC in S had at least a 10 times greater incidence of developing a malignant or autoimmune disease than the other 28 patients. The 11 patients with 41-51% in GM-CFC in S had greater than 1 x 10(9) neutrophils/1 and no significant clinical problems but all have remained mildly neutropenic for a long period. An indirect relationship existed between the degree of neutropenia and the proportion of GM-CFC in S (r = -0.70).

Adult↗
PubMed1983

Immunoradiometric assay of plasma lactoferrin.

The concentration of lactoferrin, a non-heme iron binding glycoprotein, was determined in more than 1500 EDTA plasma samples by a 2-site solid phase immunoradiometric assay to assess the significance of lactoferrin in plasma and to investigate applications for this assay. The use of commercially available antibody and antigen and a relatively short assay time make this assay more suitable for use in routine clinical laboratories than previous methods. A normal range of 250-750 micrograms/l was established. There was a correlation between plasma lactoferrin concentration and the circulating blood neutrophil count in most patients except those with splenomegaly, post-splenectomy and undergoing intensive chemotherapy. Patients with gross splenomegaly usually had an increased and post-splenectomy patients a decreased lactoferrin/neutrophil ratio indicating a respective increase and decrease in the marginated pool. In patients with acute leukemia after chemotherapy or transplantation plasma lactoferrin levels increased 1 to 5 d before blood neutrophil counts rose. As plasma lactoferrin seems to be derived from neutrophils, its concentration is probably related to the size of the total blood granulocyte pool. Calculation of the lactoferrin/neutrophil ratio demonstrated variations in the size of the bone marrow reserve and the marginated neutrophil pool.

Humans↗
PubMed1983

A new hemoglobin with high oxygen affinity--hemoglobin bunbury: alpha 2 beta 2 [94 (FG1) Asp replaced by Asn].

Hemoglobin Bunbury was detected in an Italian woman from Bunbury, Western Australia, following detection of an abnormal hemoglobin by electrophoresis. The variant form accounted for 38% of the total hemoglobin and migrated on cellulose acetate electrophoresis between HbS and HbA. Structural analysis demonstrated a new substitution in the beta chain, beta 94 Asp replaced by Asn. Hemoglobin Bunbury is stable to both heat and isopropanol denaturation. This variant shows an increase in oxygen affinity and a reduced Bohr effect. Heterozygosity for Hb Bunbury produces no clinical symptoms or compensatory erythrocytosis.

Adult↗
PubMed1982

A study of the true competitive protein binding of current vitamin B12 radioassays.

The use of purified intrinsic factor in vitamin B12 radioassays has greatly reduced the misdiagnosis of pernicious anaemia in recent years, but anomalies still occur. Observations made on current vitamin B12 radioassays suggest that many methods fail to convert all serum cobalamins to cyanocobalamin and thus are not true competitive protein binding assays. No KCN in the extraction buffer resulted in an average 30% reduction in the vitamin B12 level in normal sera. High concentrations of KCN caused a significant increase in the vitamin B12 level in serum from most vitamin B12 deficient patients. This increase could have caused a misdiagnosis in 7 of 12 patients studied. The specificity of (57Co) cyanocobalamin binding to both transcobalamin II (TCII) in a pool of normal sera and to intrinsic factor in a commercial kit binder reagent was 99%. We conclude that the KCN concentration in the extraction mixture should be between 2 and 5 mg/l.

Anemia, Pernicious↗
PubMed1982

Folate assays--an alternative to microbiological assays and commercial kits.

A simple and reliable folate radioassay technique based on the principles of classic folate radioassays but incorporating several of the recently introduced technical innovations is presented as an alternative to the microbiological assays and commercial kits. Serum and red cell folate values from this method were compared with results from two commercial kits and a Lactobacillus casei (L. casei) assay. There was a good correlation with the L. casei assay for both serum and red cell folate (r = 0.95). The method uses N-methyltetrahydrofolate standards diluted in folate free serum, beta-lactoglobulin as a binder and an alkaline denaturation ('no-boil') of endogenous folate binding proteins. Low hematocrit lysates were best performed at a 1 in 10 rather than 1 in 20 dilution. A comparison of the boil and 'no-boil' kits from Diagnostic Products Corporation revealed that the 'no-boil' kit produced results closer to those obtained from the L. casei assay than the boil kit.

Biological Assay↗