Mechanism of post dialysis hyperventilation in patients with chronic renal insufficiency.

Several hypotheses have been put forward to explain postdialysis hypocapnia. Three were tested in this study: impairment of tissue oxygenation by dialysis (D)-induced alkalosis (Bohr effect), the D disequilibrium syndrome, and the loss of carbon dioxide (CO2) in D fluid. In 17 patients pre-DPCO2 was significantly correlated with plasma bicarbonate concentration (HCO3) and no disproportionate reduction of PCO2 was discernible. In 10 patients using a bath acetate concentration of 38 mEq/1 PCO2 was unchanged after D (35.4 versus 35.9 mm Hg before D), and was low relative to HCO3 whic increased from 21.2 to 28.0 mEq/1. After a dialysis using an acetate concentration of 25 mEq/1 HCO3 remained constant (20.4 versus 21.1 mEq/1 pre-D), whereas PCO2 fell from 35.3 to 30.8 mm Hg (P less than 0.001). Consequently PCO2 was again low relative to HCO3. Removal of CO2 by D fluid was excluded as a cause for low blood PCO2: addition of gaseous CO2 to the bath had no influence on arterial blood gases. Since post-D hypocapnia was not prevented when HCO3 was kept constant, it was concluded that post-D alkalosis cannot be the main reason for post-D hyperventilation, and that other factors related to the process of D are responsible.

Red cell survival and red cell enzymes in patients on continuous peritoneal dialysis (CAPD).

In 11 patients on CAPD with persisting anemia the survival of red cells labelled with 51Cr, red cell mass and the levels of several enzymes within red cells were measured. 51Cr red cell survival was shortened in 9/11 (mean +/- SD:20.0 +/- 4.9 days) and correlated with red cell mass, i.e. with the degree of anemia (r = 0.79, P less than 0.01). Determinations of the levels of enzymes of the hexose monophosphate shunt and the glycolytic pathway revealed no obvious defects in red cell metabolism. The level of hexokinase (HK) was normal whereas the activities of glucose-6-phosphate dehydrogenase (G-6-PD), 6-phosphogluconate dehydrogenase (6-PGD), glutathione reductase (GR) and pyruvate kinase (PK) as well as reduced glutathione (GSH) were increased significantly. CAPD did not eliminate the hemolytic component of anemia in the majority of these patients.

[Hemoglobinopathies in developing countries]. / Hämoglobinopathien in Entwicklungsländern.

The most important haemoglobinopathies in developing countries are reviewed in the light of new results elicited with modern research approaches. It has been shown that the sickle mutation originating in a localized region in West Africa arose independently of the mutation in East Africa and Asia. The frequency of alpha-thalassaemia has been underestimated in mediterranean and African countries. The inherited resistance to Plasmodium falciparum in the sickle cell disorders and thalassaemia has been elucidated to a large extent. The heterogeneity of alpha- and beta-thalassaemia has been investigated at the molecular level of the globin genes. Clinical management with repeated blood transfusions and regular iron chelation has markedly improved life expectation of the patient with thalassaemia major. Screening and educational programmes on a large scale in combination with facilities for genetic counselling, prenatal diagnosis and therapeutic abortion have already reduced the incidence of serious haemoglobinopathies in several developed countries. However, these methods will not be available for the population of developing areas until these countries reach a generally higher level, both economically and socially.

[Probe test for the detection of hemoglobinopathies and enzyme defect anemias]. / Suchteste zur Erfassung von Hämoglobinopathien und Enzymdefektanämien.

The simplest methods for the diagnosis of thalassaemias are the morphology of erythrocytes, the Hb-F-elution test and the Hb H Heinz bodies test. In order to prove the sickle cell anomaly sickle cell preparation and Hb-S-precipitation test can be performed in every laboratory. By means of the isopropanol precipitation test or the Heinz bodies test can be searched for instable haemoglobins without any laboratory expenditure. On the other hand, haemoglobins with increased oxygen affinity demand a measurement of the oxygen affinity of the erythrocytes. However, simple fluorescence or dye-stuff methods are out our disposal for the most important erythrocytic enzymopenias.

[Medical education]. / Die Erziehung zum Arzt.

There can be no doubt about the need for more comprehensive medical education. Increasing pressure has been brought to bear from outside on health care, calling for humanization and extension into hitherto neglected areas such as health disorders due to psychological, professional, familial and environmental problems. A new education and re-education programme must include an ethical basis, communication and cooperation with patients and exchange of the biomedical model for a biopsychosocial model of disease.

[Hemotherapy in malignant hematologic diseases]. / Hämotherapie bei malignen Blutkrankheiten

For the majority of patients with malignant blood diseases the ideal transfusion products are blood components instead of whole blood. The therapeutic use of packed red cells, platelets, leukocytes and albumin is briefly discussed.

[Clinical demonstrations of hereditary disorders of metabolism]. / Klinische Demonstrationen von hereditären Stoffwechselstörungen.

Case reports are presented on 4 outpatients with hereditary disorders of metabolism. 1. In a 46-year-old male of Sicilian origin with haemolytic anaemia and leg ulcers, the blood contained numerous target cells, the sickling test was positive, and more than 80% of the haemoglobin was found to be HbS. Investigation of the family revealed double heterozygosity for HbS and beta-thalassaemia. 2. In a family with hereditary nonspherocytic haemolytic anaemic, the biochemical characterization of an abnormal pyruvate kinase is reported: the kinetic data were found to be normal, the electrophoretic migration rate of the abnormal enzyme was increased, and its thermostability was marked decreased. 3. Malignant hyperthermia was observed in an 18-year-old male. The limited value of all methods for identifying affected family members is discussed. 4. In 2 sisters who suffered life-threatening attacks of acute myoglobinuria, differential diagnosis comprised hereditary deficiency of phosphofructokinase, muscle phosphorylase and carnitine palmityl transferase. The activity of the former two enzymes was found to be normal. The circumstances of the myolytic crisis in the two patients provide strong evidence for the presence of a muscle carnitine palmityl transferase deficiency.

[Clarification of anemia: quality control in the general practice laboratory]. / Abklärung einer Anämie: Qualitätskontrolle im ärztlichen Praxislaboratorium.

In mailed blood samples from 602 adult patients with beta-thalassaemia trait, a mean MCH value of 20.5 pg with a 2 s range of 17-24 pg was found. These values are identical to those determined in fresh blood samples. Furthermore, the Gaussian distribution indicates that reliable values are obtained in mailed blood samples. From patients with previous blood analyses in hospital and biochemical laboratories the MCH values of the foreign laboratories correlated well with our results (r = 0.87). On the other hand, a poor correlation was observed for private practice laboratories (r = 0.71). The difference of the two correlation coefficients is statistically highly significant (p less than 0.001). There is clearly a need for MCH quality control in the laboratories of many practitioners. Continuous quality control by means of values from healthy persons and the use of stabilized control blood is recommended.

[50 years of Swiss Academy of Medical Sciences]. / 50 Jahre Schweizerische Akademie der medizinischen Wissenschaften.

The Swiss Academy of Medical Sciences is a foundation under private law, which was founded September 24, 1943, by the Medical and Veterinary Faculties of the Swiss universities and the Swiss Medical Association. It devotes its resources to the advancement of the medical sciences and awards research grants, scholarships and scientific prizes. Its other services include a scientific documentation service (DOKDI), the medical-ethical evaluation of research projects and the publication of guidelines and recommendations for physicians, particularly concerning ethical standards of behaviour. The 50 years' existence of the institution will be commemorated at a ceremony to be held in Berne September 23, 1993.