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R Burkhardt

Publications and source records attributed to R Burkhardt.

At least 55 records · Page 3Linked to original sources
PubMed1982

Assessment of bone marrow histology in Hodgkin's disease: correlation with clinical factors.

Bone marrow biopsies of 491 untreated and 170 treated patients with Hodgkin's disease (HD) were investigated. Marrow involvement was found in 10% and 25% respectively. Positive biopsies were rare in clinical stages I and II (1% and 2%), but the incidence rose to 25% and 45% in stages III and IV. HD patients with nodular sclerosis in lymph node histology had a low incidence of bone marrow involvement (4%), while those with lymphocytic depletion had a high incidence (22%). Of nine clinical and six histological parameters tested, bone marrow involvement proved to be the most significant predictive factor indicating an unfavourable course. Moreover, classification of the bone marrow manifestations according to the degree of lymphocytic infiltration, proved to be simple, reproducible and prognostically significant. Normal haematopoietic tissue was found in only 20% of the negative biopsies of untreated patients. The remaining 80% were characterized by a variety of non-specific reactions. These included marrow hypoplasia and leukaemoid and exudative reactions each of which indicated a poor prognosis; and epithelioid-cell granulomas and lymphoid nodules which predicted favourable survival curves. Adequate bone marrow biopsy is a valuable part of the investigation of patients with HD, as both positive and negative biopsies provide information of prognostic significance.

Adolescent↗
PubMed1982

Bone marrow histology in myeloma: its importance in diagnosis, prognosis, classification and staging.

A study has been made of 420 bone marrow biopsies from patients with multiple myeloma (220), idiopathic monoclonal gammapathy (50), reactive plasmacytosis (42) and solitary plasmacytoma (22). Histology and immunohistological parameters were more reliable than cytology in distinguishing a reactive from a neoplastic plasmacytosis. Histological variables were correlated with the clinical features of the patients to determine the factors which were of value in predicting prognosis. Plasma cell maturity and the extent of infiltration in the biopsy by myeloma cells proved to be highly significant in predicting the duration of survival. On the basis of these criteria multiple myeloma was classified into two types: plasmacytic of low-grade malignancy and plasmablastic of high-grade malignancy; and into three stages which accurately reflected the progression of the disease. We conclude that a bone biopsy provides useful information for the diagnosis, classification and staging of patients with multiple myeloma.

Bone Marrow↗
PubMed1982

Assessment of bone marrow histology in the malignant lymphomas (non-Hodgkin's): correlation with clinical factors for diagnosis, prognosis, classification and staging.

Bone marrow biopsies of 678 untreated patients with established malignant non-Hodgkin's lymphomas (ML) were investigated. The bone marrow was involved in 468 cases, an overall frequency of 69%. The Kiel classification of the ML (based on lymph node histology) was applied and the biopsies were classified: ML lymphocytic 36%, ML 'hairy cell' 24%, ML lymphoplasmacytic/cytoid 24%, ML centrocytic 6%, ML centroblastic/centrocytic 4%, ML lymphoblastic (without ALL) 3%, ML centroblastic 2% and ML immunoblastic 1%. The life tables of the patients were similar whether classified according to the histology of the lymph node or the bone marrow. A multivariate computer based analysis of both clinical and histological data was performed to test their prognostic relevance. The cell type, the proliferation pattern and the extent of infiltration in the bone marrow all proved to be factors of prognostic significance. The results indicate that classification of the ML based on lymph node histology is applicable to the bone marrow, is reproducible and has prognostic significance. Consequently, a bone marrow biopsy is a useful clinical tool for staging and for histological classification of patients with ML.

Bone Marrow↗
PubMed1982

Chromosomal genes for ColV plasmid-determined iron(III)-aerobactin transport in Escherichia coli.

Four chromosomal genes, tonA (fhuA), fhuB, tonB, and exbB, were required for the transport of iron(III)-aerobactin specified by the plasmids ColV-K311, ColV-K229, ColV-K328, and ColV-K30. These genes also determine the transport system in Escherichia coli for the iron ionophore ferrichrome. Aerobactin and ferrichrome are both iron ligands of the hydroxamate type, but they are of different structure. The ColV plasmids determine an outer membrane protein that serves as a receptor for cloacin. Cloacin-resistant mutants were devoid of iron(III)-aerobactin transport but were unimpaired in ferrichrome transport. We conclude that for iron(III)-aerobactin transport two outer membrane proteins, the TonA and the cloacin receptor protein, have to interact functionally or structurally or both.

Bacterial Outer Membrane Proteins↗
PubMed1982

Regulation of the ColV plasmid-determined iron (III)-aerobactin transport system in Escherichia coli.

Regulation by iron was studied in Escherichia coli strains whose iron supply was entirely dependent on the iron(III)-aerobactin system determined by the ColV plasmid. By the insertion of phage Mu (Ap lac) into the ColV plasmid, mutants were selected that could no longer grow in iron-limited media. The inserted Mu (Ap lac) strongly reduced the amount of aerobactin and he cloacin receptor protein formed by the cells. Their production was no longer subject to regulation by iron. The Mu (Ap lac) insertion apparently led to a polar effect on the expression of the presumably closely linked genes that control the synthesis of aerobactin and the cloacin receptor protein. The expression of the beta-galactosidase gene on the inserted phage genome came under the control of the iron state of the cells. Under iron-limited growth conditions, the amount of beta-galactosidase synthesized was, depending on the strain studied, 6 to 30 times higher than under iron-sufficient growth conditions. In fur mutants with an impaired iron regulation of ll iron supply systems studied so far, high amounts of beta-galactosidase were synthesized independent of the cells' iron supply. The results demonstrate an iron-controlled promoter on the ColV plasmid which is subject to regulation by the chromosomal fur gene.

Bacteriocin Plasmids↗
PubMed1982

Bone biopsy in haematological disorders.

Bone marrow biopsies are now widely used in the investigation and follow-up of many diseases. Semi-thin sections of 8216 undecalcified biopsies of patients with haematological disorders were studied. Observations were made on the cytopenias and the myelodysplastic syndromes, the acute leukaemias the myeloproliferative disorders, Hodgkin's disease and the malignant lymphomas including multiple myeloma, hairy cell leukaemia and angioimmunoblastic lymphadenopathy. Bone marrow biopsies are essential for the differential diagnosis of most cytopenias and for the early recognition of fibrosis which most frequently occurred as a consequence of megakaryocytic proliferation in the myeloproliferative disorders. Different patterns of bone marrow involvement were found in the lymphoproliferative disorders and both their type and extent constituted factors of prognostic significance. A survey of the literature is given and the conclusion is drawn that bone marrow biopsies provide indispensible information for the diagnostic evaluation and the follow-up of patients with haematological disorders.

Anemia↗
PubMed1982

Bone marrow biopsy in clinical medicine: an overview.

Bone marrow biopsies are now employed in the investigation of many disorders in haematology, oncology and internal medicine. This review provides a survey of the recent literature and a summary of observations made on undecalcified bone marrow biopsies embedded in plastic. The conditions investigated include osteopathies, myelopathies, haematologic and non-haematologic malignancies in the bone marrow. The interrelationship and interdependence of bone and bone marrow have been emphasized, and examples of the effects of diseases of bone on marrow, and of disturbancies of marrow function on bone, have been given. In the myelo- and lympho-proliferative disorders bone marrow biopsies contribute to diagnostic evaluation and classification, as well as to provide factors of prognostic significance. In the investigation of patients with solid tumours bone marrow biopsy may detect metastases in 20 per cent (bronchus), 35 per cent (prostate), 40 per cent (breast), to 80 per cent (unknown primaries) of the patients. Bone marrow biopsy constitutes an additional investigative parameter capable of providing valuable information in many different clinical situations.

Adolescent↗
PubMed1982

Prolonged in vivo stimulation of the rat exocrine pancreas by caerulein infusion. Biochemical effects.

Chronic secretory stimulation of the rat exocrine pancreas by continuous infusion of 0.1825 nmol/kg . h caerulein for 4 to 8 days as well as by a dose increased fivefold after the first 3 days of treatment results in three clearly distinct modes of pancreatic reaction apparently independent of the treatment pattern. One group of animals developed degranulation of acinar cells, low enzyme content, and accelerated intracellular transport and discharge of newly synthesized proteins as expected after secretory stimulation. A second group exhibited a striking overgranulation of acinar cells and extremely high enzyme content. In vitro intracellular transport rates were normal and zymogen output per cell in response to caerulein stimulus was elevated. The third group developed apparent desensitization towards hormonal stimulus in vivo. Enzyme content was slightly elevated and secretory behaviour in vitro similar to controls. Basal secretion rates were elevated in most pancreata of all 3 groups, possibly due to persistence of stimulatory effect of caerulein given in vivo up to the moment of sacrifice. Enzyme composition was strikingly changed in favor of the proteases trypsinogen and chymotrypsinogen in all pancreata.

Animals↗
PubMed1981

[Twelve theses on the pathogenesis of primary and secondary osteoporosis based on histological observations].

In spite of a well defined clinical syndrome and a wealth of biochemical information, the pathogenesis of primary osteoporosis is still uncertain. Microscopic evaluation of semithin sections of 1727 bone biopsies from patients suffering from "idiopathic" osteoporosis and 288 from patients with secondary osteoporosis has lead to the recognition of a pathogenetic relationship between changes of the bone marrow capillaries and atrophy of the trabecular bone in these groups. A new hypothesis is proposed for the structural and functional role of the bone marrow capillaries in normal and abnormal osseous remodelling; this is based on comparative morphometric analysis of normal cases and of hypo- and hyperplastic changes of the myelogenous and osseous tissues in various haematological and bone disorders. The hormonal and nervous regulation of the microcirculation of bone marrow may offer a new approach to the understanding and cure of so-called idiopathic osteoporosis.

Adult↗