Biomedical subjects
Publications and source records attributed to A Hellmann.
The clinical and cytogenetic findings of a patient with refractory anemia with excess of blasts are presented. Trisomy 13 was present as the sole numerical aberration in all analyzed bone marrow metaphases; this finding has not been reported previously in myelodysblastic syndrome.
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Calcium ions are thought to mediate hormonal and cholinergic stimulation of exocrine pancreatic secretion. In order to further eludicate the role of calcium ions in stimulus-secretion coupling of the pancreas, the effect of the calcium antagonist verapamil, which inhibits transmembrane calcium influx, was studied on pancreatic secretion in 35 healthy male volunteers. Every subject had two stimulation periods of 2 hr each with a 3-hr period between the two. Pancreatic secretion was stimulated by cholecystokinin in 12 subjects, by secretin in 14 subjects, and by sham feeding in 6 subjects. Three subjects were studied without any secretory stimulus. Verapamil as an intravenous bolus of 150 micrograms/kg followed by an intravenous infusion of 150 micrograms/kg/hr or saline were given during the two 2-hr stimulation periods in a randomized order. The pancreatic secretory responses to stimulation by cholecystokinin, secretin, or sham feeding, as well as the basal pancreatic secretion without a secretory stimulus were left unaffected by verapamil when compared to the saline control. The results, therefore, call into question the hypothesis that transmembrane calcium influx is a major mediator of pancreatic secretion in response to hormonal or cholinergic stimulation in man.
The effect of an intravenous infusion of a 10% fat solution containing 50 g/l medium chain triglycerides (MCT) and 50 g/l long chain triglycerides (LCT) on exocrine pancreatic secretion was studied in 18 healthy volunteers. Each subject was studied twice on separate days. In period I 0.9% NaCl was given intravenously on both days. In the following period II either a 10% solution of MCT-fat or 0.9% NaCl were given intravenously in a randomized order at a rate of 100 ml/h. Periods I and II lasted 150 minutes each. Throughout the experiment pancreatic secretion was stimulated by saline, 0.1 U/kg/h secretin, or 0.25 U/kg/h secretin in 6 subjects each. In period II, MCT/LCT infusions did not influence pancreatic outputs of volume, bicarbonate and enzymes when compared to the NaCl infusion in the control experiment irrespective of the type of stimulation. Therefore, intravenous infusions of MCT may be used in clinical situations where the pancreas should be kept at full rest.
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A family is described in which the father and son had erythrocytosis associated with a normal Hb oxygen affinity. Growth of erythroid colonies in vitro (BFU-E) exhibited normal erythropoietin dependence. In the son there was an enlarged erythroid precursor compartment, while the father (who had been treated by busulphan) showed marked reduction of circulating BFU-Es. Serum erythropoietin (Epo), estimated by radio-immunoassay, was 96 miu/ml in the son and 360 miu/ml in the father (normal 25, SD 6, n = 46). We conclude that erythrocytosis in this family is due to a genetically determined hyper-production of Epo. The finding in the father of a high Hb level associated with increased Epo and decreased BFU-Es might support the hypothesis that red cell mass is regulated by Epo at the level of bone marrow CFU-Es rather than BFU-Es.
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Colony formation by granulocyte/macrophage and eosinophilic progenitor cells in the blood and/or bone marrow of four patients with "hypereosinophilic syndrome' (HES) was studied in agar culture. Colony-stimulating activity (CSA) was derived from leucocyte feeder layers (LFL) or from medium conditioned by phytohaemagglutinin-stimulated lymphocytes (LCM). The total numbers of colonies in the patients' blood and marrow were normal. When patients' marrow cells were cultured over LFL, the proportion of colonies that were eosinophilic was greater than normal (mean 21% vs 6%, P less 0.001) and this difference was accentuated when CSA was derived from LCM (mean 53% vs 15%, P less than 0.001). LCM derived from normal subjects and LCM prepared from HES patients had similar effects. In the blood the total number of colonies and the proportion of eosinophilic colonies were similar in patients and controls. The overall pattern of colony formation HES differed distinctly from that observed in a patient with eosinophilic leukaemia reported previously. We conclude that the proportion of eosinophil-committed progenitor cells in the marrow of patients with HES is increased, but we have failed to demonstrate a role for the patient's own lymphocytes in augmenting eosinophil production.
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Culture medium was harvested after co-incubation of mononuclear cells collected and pooled from the peripheral blood of two different normal donors and was tested for colony-stimulating activity (CSA) in agar culture. With bone marrow from normal donors or peripheral blood from patients with chronic granulocytic leukaemia as sources of granulocyte-committed progenitor cells (CFU-c), such mixed mononuclear cell conditioned medium (MMC-CM) showed activity equal to that of unfractionated leucocyte feeder layers and greater than that of CSA prepared from lymphocytes stimulated by phytohaemagglutinin. The addition to plates of 2-mercaptoethanol during the preparation of MMC-CM enhanced CSA release. MMC-CM is thus a convenient source of CSA and its use may be preferable to that of feeder layers when day-to-day reproducibility is essential.
We measured the concentration of granulocyte-committed progenitor cells (CFU-c) and the alkaline phosphatase activity of neutrophils harvested from colonies cultured from the peripheral blood of 30 patients with high-count chronic granulocytic leukaemia (CGL) in the chronic phase. Neutrophils in colonies cultured from marrow of normal donors or patients with acute myeloid leukaemia in remission served as controls. CFU-c numbers in CGL peripheral blood were on average 3 times higher than in normal marrow (130.1 +/- 126.2 (SD) versus 43.0 +/- 25.2 per 1 X 10(5) cells plated, respectively). The mean NAP scores in cultured CGL neutrophils were substantially higher than control values (89.9 +/- 48.0 versus 55.9 +/- 33.0 units, respectively). There was a tendency for peak values of NA in culture to be reached at earlier points in CGL cultures with high CFU-c numbers (i.e. high proliferative rates) than in those with lower CFU-c numbers (lower proliferative rates). Our data accord with the concept that low NA levels in CGL in vivo result from modulating influences external to the neutrophil.
Coagulation and fibrinolysis were measured in the portal and peripheral circulation in 15 rabbits after ligation of the superior mesenteric artery. It was found that the local coagulation syndrome in the mesenteric region can be recognized by tests in blood samples taken from the peripheral circulation area.
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