Detection and quantification of transforming growth factor beta (TGF-beta) and platelet-derived growth factor (PDGF) release by normal human megakaryocytes.

Transforming growth factor beta (TGF-beta) and platelet-derived growth factor (PDGF) are known as protein cytokines involved in differentiation as well as in maturation processes within the hematopoietic system. Both enhance the proliferation and/or collagen synthesis in fibroblasts and are found within the alpha-granules of megakaryocytes. To learn more about the regulation mechanisms involving synthesis and secretion of these cytokines it is important to develop suitable experimental conditions. We have applied the reverse hemolytic plaque assay (RHPA) to CD61+ megakaryocytes prepared from bone marrow of hematologically normal patients. By means of the RHPA, the spontaneous and stimulated secretion of TGF-beta 1 and PDGF could be analyzed at the single cell level. According to morphometric analysis, predominantly small megakaryocytes including precursors (pro- and megakaryoblasts) secrete TGF-beta 1 and PDGF under physiological conditions. Furthermore, the proportion of actively secreting megakaryocytes increased significantly following treatment with recombinant human (rh) IL-3 for 8 h. A slight induction was also appreciated after stimulation with interleukins rhIL-1 or rhIL-11. Because IL-3 as well as IL-11 are known as efficient growth factors for human megakaryocytes in vitro, our data provide insights into the regulatory mechanisms involved in megakaryopoiesis and the development of myelofibrosis.

[Diabetic coma with deep hypothermia. Successful resuscitation with hemofiltration]. / Diabetisches Koma mit tiefer Hypothermie. Erfolgreiche Reanimation mittels Hämofiltration.

A 41-year-old woman with severe juvenile diabetes mellitus suffered from profound hypothermia after loss of thermoregulation in diabetic ketoacidosis. She was found unconscious, without measurable blood pressure; the electrocardiogram (ECG) showed bradycardia of 30 min and the rectal temperature was 23.7 degrees C. The patient received mechanical ventilation, fluid therapy, warmed gastric lavage, and, unfortunately, inotropic medication. She was transferred to a department of cardiac surgery in order to continue the therapy with cardiopulmonary bypass (CPB). On arrival, the patient had a rectal temperature of 27.3 degrees C, the ECG showed an absolute arrhythmia with a frequency of 70/min, and the blood pressure was 63/43 mmHg. We decided to use a rapidly available but not highly invasive venovenous hemofiltration technique for slowly rewarming the patient. Vascular access was achieved by percutaneous femoral vein cannulation with a Shaldon catheter. The hemofiltration system (Gambro AK-10, Gambro AB, Sweden) was instituted with a blood flow rate of 200 ml/min. The hemofiltration monitor controls the pumps for filtering and substituting fluid volumes and allows the infusion solutions to be heated up to 40 degrees C. Sinus rhythm resumed without antiarrhythmic medications at a temperature of 29.5 degrees C, and within 8 h the patient was rewarmed to 35.5 degrees C. After treatment of the adult respiratory distress syndrome caused by pneumonia, she was discharged from the intensive care unit to complete treatment with no evidence of any permanent organ damage. We conclude that hemofiltration may be the method of choice for rewarming deeply hypothermic patients when their circulation is preserved.(ABSTRACT TRUNCATED AT 250 WORDS)

[Bland-White-Garland syndrome. Clinical aspects, diagnosis, therapy]. / Das Bland-White-Garland-Syndrom (BWGS). Klinik, Diagnostik, Therapie.

The anomalous origin of the left coronary artery from the pulmonary artery (Bland-White-Garland Syndrome) is a rare congenital malformation reported to occur in 0.25-0.5% of all congenital cardiac anomalies. The clinical and pathomorphological picture can be classified into 2 types: infantile or adult. The infantile type is thought to lack coronary collaterals; this explains the bad prognosis and symptoms of non-operated patients. In the adult type collaterals are present or have developed in time to provide adequate blood supply to the myocardium. No history of cardiac complains and a nearly normal ECG are common findings. Echocardiography and cardiac catheterisation are mandatory diagnostic tools. The value of new methods like NMR, "stop-flow" angiography and color doppler flow mapping is still in discussion. The reimplantation of the coronary artery and Takeuchi-Operation are well established surgical methods. The time for the operation and prognostic outcome are related to the preoperative underlying myocardial damage measured by left ventricular function.