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Biomedical subjects

H Karle

Publications and source records attributed to H Karle.

At least 37 records · Page 2Linked to original sources

[Future collaboration in medical education in Scandinavia].

The Nordic Federation for Medical Education is in the process of re-organisation. Owing to increasing cooperation with the remainder of Europe, it is desirable that the Nordic countries unite to preserve the structure of Nordic medical education.

Education, Medical↗

[Renaissance of the reticulocyte].

Flowcytometric enumeration of reticulocytes using RNA-binding fluorochromes, a method both sensitive and reproducible, is rapidly gaining ground. It performs conspicuously better than the traditional manual method of reticulocyte counting, which is unacceptably inaccurate. The reticulocyte count is a valuable indicator of erythropoietic activity, of essential importance in discerning between the aregeneratory anaemias and anaemias accompanied by an adequate, partial or complete compensatory erythropoietic response. The reticulocyte count can be applied to the monitoring of the response to treatment including both allogeneic and autologous bone marrow transplantation, as well as to the evaluation of the response to recombinant human growth factors. The mean fluorescence intensity of reticulocytes enumerated by the flowcytometric analysis, is a variable possessing an independent clinical value for calculation of a reticulocyte production index and an erythropoiesis index.

Flow Cytometry↗

Short-term myeloid growth factor mediated expansion of bone marrow haemopoiesis studied by localized magnetic resonance proton spectroscopy.

Previously we have shown that short-term myeloid growth factor priming of haemopoiesis prior to bone marrow harvest increased the yield of myeloid progenitors in the graft. The present study is intended to investigate the expansion of haemopoiesis by volume selective proton magnetic resonance spectroscopy (MRS). Six patients were treated with daily subcutaneous injections of recombinant human granulocyte colony-stimulating factor (rhG-CSF, n = 2) or granulocyte-macrophage colony-stimulating factor (rhGM-CSF, n = 4) for 5d before marrow harvest. MRS investigations were performed prior to treatment (day 0), day 5 and day 12. Spectroscopic examinations were performed with the stimulated echo acquisition mode (STEAM) method on a 1.5 T clinical whole-body imaging unit. A cubic volume of interest (VOI) was selected in the bone marrow of the left iliac bone. The patients responded with a rise in blood absolute neutrophil count from median 3.3 x 10(9)/l (range 1.3-7.3 x 10(9)/l) before to 15.6 x 10(9)/l (range 6.8-22.0 x 10(9)/l) after treatment. Concomitantly an increase in bone marrow cellularity and myeloid:erythroid ratios documented the stimulation of myelopoiesis. During priming, the light-density cell proliferation rate in marrow samples increased from median 21.9 (range 4.5-31) x 10(3) cpm to 54.7 (range 13.9-94) x 10(3) cpm and the total number of myeloid progenitors enumerated as day 7/14 GM-CFUs per volume aspirated marrow increased from median 11/8 x 10(3) (range 4.0-87.5/2.2-103.0) to 64/76 x 10(3) (range 28.4-1180.6/23.2-2850.0). MRS detected a significant increase in bone marrow 'relative water content' day 12, 1 week after myeloid growth factor treatment was stopped, from median 30.5% (range 16-45) to 79% (range 56-93). In parallel, haemopoiesis was detected in new areas of femur. In conclusion, the non-invasive MRS method may be a useful and reliable in vivo examination for expansion of haemopoiesis and a correspondent reduction of fat tissue in bone marrow after priming with recombinant human haemopoietic growth factors.

Adult↗

Reversible adult-onset cyclic haematopoiesis with a cycle length of 100 days.

Cyclic neutropenia is the most frequent of the cyclic haematopoietic disorders characterized by its regular 21 d cyclic fluctuations in the number of blood neutrophils, and in many cases simultaneous fluctuations in the other blood cell lines. In this paper we describe a 77-year-old woman with a cyclic pancytopenia including all the myeloid cell lines and to some extent the lymphocytes with a constant and predictable oscillation period of about 100 d. Serial bone marrow biopsies and plasma lactoferrin measurements indicated a similar fluctuating pattern in the bone marrow production of neutrophils. Serial measurements of plasma GM-CSF concentration pointed at a simple feed-back inhibitory system. The condition was present for at least 4 years, after which it gradually improved, although the thrombocyte count still showed a fluctuating tendency after a further 4 years of observation. The clinical consequences were mild symptoms of anaemia and a few episodes of respiratory infections occurring during pancytopenic periods. We think this is the first case described in the literature with this variant of a cyclic haematopoietic disorder. The precise pathophysiological mechanism behind this condition is obscure, but probably it is due to a regulatory disturbance at a very early step in the haematopoietic stem cell hierarchy.

Aged↗

Medical specialization in Europe: the way forward. Promotion of educational quality.

The medical specialties are being intensively reconsidered in the countries of Europe. The important need is for promoting improvement of educational training programmes. Evaluation and improvement of specialist training programmes is the priority and not the setting up of qualifying examinations. The first necessity is to safeguard 20 years of evolution in postgraduate training. Support for the educational process is essential, to a much greater extent than occurs at present, if standards are to be improved and the confidence of the public is to be retained. The EC medical education system is the only existing international structure in medical education which is controlled by law, and is on that basis alone of the greatest interest.

Education, Medical↗

Initial cytoreduction by mitoxantrone and cytarabine has no impact on the outcome of interferon-alfa-2b therapy in chronic myelogenous leukemia.

Eleven previously untreated patients with chronic-phase Philadelphia-chromosome-positive chronic myelogenous leukemia were treated with cytotoxic chemotherapy followed by interferon-alfa-2b (IFN-alpha) maintenance. Initial chemotherapy consisted of three cycles of mitoxantrone 10 mg/m2 on day 1 and 2, and cytarabine 100 mg/m2 daily for 5 d. Complete hematological response was obtained in 9 (82%) patients with moderately associated toxicity. However, cytogenetic responses after three cycles were poor and transient (1 partial suppression and 2 minor suppression of Ph chromosome). Maintenance therapy with IFN-alpha was started in 10 patients at 5 x 10(6) U/m2 daily with dose reduction if hematologic toxicity or severe side-effects occurred. Of 9 evaluable patients treated for more than 3 months, 6 patients maintained a complete hematological response, whereas 1 patient remained in partial remission and 2 patients showed progressive disease. Cytogenetic evaluation showed partial suppression of Ph chromosome in 1 patient, whereas 1 patient had a minor response and 5 patients had no change or evolution of new chromosome abnormalities. As the results are not superior to IFN-alpha treatment alone, it is concluded that initial cytoreduction by mitoxantrone and cytarabine has no impact on the outcome of therapy in CML.

Adult↗

Prophylactic effect of self-administered pump-driven subcutaneous IgG infusion in patients with antibody deficiency: a triple-blind cross-over study comparing P-IgG levels of 3 g l-1 versus 6 g l-1.

Eight adult patients with hypoimmunoglobulinaemia were randomly allocated to initiation of low- or high-level IgG-substitution. IgG was administered subcutaneously, at 50 or 150 mg ml-1, 20 ml per infusion, by means of a pocket-portable electric infusion pump. Infusions were given 2 to 4 times weekly for 24 months, with a change of dose regimen after 12 months. The desired plasma IgG levels were reached after a mean lag phase of 3 months (range 1-5 months). The median (and ranges) of the individual mean plasma IgG levels during the ensuing 9-month periods were as follows: high-level period, 6.5 g l-1 (range 6.2-7.8 g l-1); low-level period, 3.2 g l-1 (range 3.0-4.0 g l-1). During the high-level period, compared to the low-level period, there was a significant decrease in the following parameters: 'days in bed at home', 'days missed work' and 'days with fever'. No serious side-effects were observed. It is concluded that a plasma IgG concentration of 6 g l-1 can readily be achieved by subcutaneous IgG substitution, and the prophylactic effect is superior to that obtained with a plasma IgG concentration of 3 g l-1.

Adult↗

Localized in vivo proton spectroscopy of the bone marrow in patients with leukemia.

Volume selective magnetic resonance (MR) proton spectroscopy was used to investigate the haemopoietic (iliac bone) and fatty bone marrow (tibia) in patients with leukemia and polycythaemia vera. Selective measurements of the relaxation times T1 and T2 for the "water" and "fat" resonances in the bone marrow spectra were performed. Nine patients with acute leukemia and three patients with chronic leukemia were examined at diagnosis. Three patients with acute leukemia in remission were also examined. Five of the leukemic patients had follow-up examinations performed in relation to chemotherapeutic treatment. Nine patients with polycythaemia vera and 21 normal control subjects were examined with identical methods for comparison. All patients had bone marrow biopsies performed prior to every MR examination. Significant differences could be detected in the spectral patterns from iliac bone marrow in patients with leukemia at diagnosis compared to the healthy normal controls. The "relative water content" was increased in the iliac bone marrow spectra of the leukemic patients compared to the normal subjects, which indicates an increase in the amount of haemopoietic tissue and a corresponding decrease in marrow fat content. The T1 relaxation times of the "water" resonance in the spectra from the iliac bone marrow of the leukemic patients were significantly prolonged at diagnosis, compared to the normal controls and the patients with polycythaemia vera. After chemotherapeutic induction of remission, the spectra from the iliac bone marrow in the patients with leukemia resembled normal spectra. Four leukemic patients had abnormal spectra from the tibial bone marrow and one patient showed early changes in tibial marrow during chemotherapeutic treatment, before any major changes could be detected in the iliac bone marrow.

Bone Marrow↗

Effects of recombinant human erythropoietin on the haemopoietic bone marrow monitored by magnetic resonance spectroscopy in patients with end-stage renal disease.

Volume selective magnetic resonance (MR) proton spectroscopy was used to investigate changes in the haemopoietic bone marrow in patients with end-stage renal disease undergoing treatment with recombinant human erythropoietin (rHuEPO). Significant changes could be detected in the spectra 14 days after the beginning of treatment, before any response was seen in the haemoglobin concentration of peripheral blood. The spectral changes indicate an alteration in cellular composition of haemopoietic bone marrow with an increase in the amount of haemopoietic active tissue. One patient showed a major change in the spectrum four days after treatment began, indicating that MR spectroscopy may detect early changes in the cellular composition of the bone marrow. This noninvasive method may be useful in evaluating treatment effects of recombinant human haemopoietic growth factors in the bone marrow, as well as investigating bone marrow response from different modes of rHuEPO administration.

Adult↗

Determination of T1- and T2-relaxation times in the spleen of patients with splenomegaly.

Twenty-nine patients with known splenomegaly and seven healthy volunteers were examined. The T1 and T2 relaxation times were read out from a region of interest centrally in the spleen. Even though different mean T1 and T2 relaxation times were found between the groups, the great scatter and the considerable overlap between the groups makes the contribution of relaxation time measurements to the differential diagnosis of splenomegaly of limited value.

Diagnosis, Differential↗