Biomedical subjects
Publications and source records attributed to H Voss.
The case history, clinical course, the diagnostic procedures and pathomorphological findings in a very rare case of a traumatic rupture of the atrial septum combined with an anterior myocardial infarction in a 30-year-old male are described. The patient recovered from his injuries to a moderate state by means of intensive care but died on the 19th day after admission.
An L-amino acid oxidase (L-amino-acid oxygen oxidoreductase (deaminating), EC 1.4.3.2) from the blue-green alga Anacystis nidulans has been purified to homogeneity with an overall yield of about 10%. Purification included ammonium sulfate fractionation and CM-Sephadex, DEAE-Sephadex, and hydroxyapatite chromatography. The purified enzyme has an absorption spectrum which is characteristic of a flavoprotein, and contains 1 mol FAD per mol enzyme. The native enzyme has a molecular weight of 98 000 as determined by gel exclusion chromatography. Electrophoresis in SDS-polyacrylamide gels gives a single protein band corresponding to a molecular weight of 49 000, which suggests that the native enzyme is composed of 2 subunits of equal molecular weight. As previously demonstrated, the enzyme catalyzes the oxidative deamination of the basic amino acids: L-arginine, L-lysine, L-ornithine and L-histidine. In the presence of catalase and of any of these amino acids, 0.5 mol O2 is consumed, and 1 mol ammonia is formed for each mol amino acid oxidized. HCN is formed from L-histidine when the L-amino acid oxidase is supplemented with peroxidase. In addition to the unusual substrate specificity of this L-amino acid ozidase, it also has an unusual set of inhibitors including o-phenanthroline as well as divalent cations of which Cu2+, Zn2+, and Cd2+ are the most effective ones, but Mg2+ and Ca2+ also inhibit. This inhibition can be reversed by chelating agents such as EDTA. ATP and ADP, but not AMP, can also overcome the inhibition caused by Mg2+, for example. The inhibitory effect of cations can be demonstrated in vivo.
Administration of 6-aminonicotinamide into eggs may interfere with the development of the chick embryo. The prevention of this effect by nicotinamide has been shown before. In the present study, it could be demonstrated that a combination of nicotinic and L-methionine may also produce this effect. If applied alone nicotinic acid exhibited low effectiveness and L-methionine none at all.
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Comparison of early and late complications of 769 endocardial pacemaker wires implanted in the period between 1969 and 1973 with 861 wires implanted between 1974 and 1978 revealed a decline of the complication rate from 17% to 7.6%. The dislocation rate could be lowered from 6.2% to 1.6%. Other early complications (exist and entrance block) were not effected (3.5% as compared with 3.2%). Late complications declined from 6.2% to 2.9%. Of these the number of intravascular wire breakages constitutes a high proportion. The main reason for this improvement is the use of a flexible Flange-tip lead. A variation of testing the positional stability of the wire is described.--The indications for pacemaker implantation shifted from 3rd degree AV-Block to the diagnoses "pathological bradycardia" and "hypersensitive carotis sinus". The comparatively low complication rate permits the application of new types of wires only in a few selected patients until a sufficient number of cases and an adequate follow-up period have been reached for clinical evaluation of these wires.
In 848 coronary arteriograms performed in a two-years period 21 patients (2.5%) showed a myocardial bridging of the left anterior descending artery. Resting- and/or stress-ECG were abnormal in half of the patients. Regional lactate-metabolism measured in the great cardiac vein at rest and during maximal atrial pacing was normal (29 +/- 12 resp. 24 +/- 9%). Thermodilution of great cardiac vein bloodflow at rest and during atrial pacing also demonstrated normal values (94 +/- 33 resp. 138 +/- 30 ml/min). Biphasic 201-Thallium myocardial imaging revealed no case of reversible perfusion defect, but surprisingly frequent (5 of 16 patients) clearly irreversible defects limited to the interventricular septum. We conclude that muscle bridges do not cause myocardial ischemia at rest or during exercise.
In an intraindividual double-blind study the effect of 1% (2.5 mg) and 2% (5 mg) reproterol aerosol was investigated in 30 patients with chronic obstructive bronchitis and asthma. Both solutions had a statistically highly significant bronchospasmolytic effect when airways resistance and specific conductance were measured. The effect was demonstrable immediately after termination of inhalation. Cardiac frequency and blood pressure remained unchanged. No subjective side effects were reported.
The basic amino acids, L-arginine, L-lysine, LO-irnithine, and to a lesser extent L-histidine, strongly stimulate the O2 uptake of cell suspensions of the blue-green alga or cyanobacterium anacystis nidulans. In the case of L-histidine, the extra O2 consumption is associated with the formation in vivo of small amounts of HCN, particularly in an atmosphere of O2. The enzyme responsible for both the stimulated O2 uptake with the basic amino acids and the formation of HCN from histidine has been isolated and identified as an L-amino acid oxidase specific for the basic amino acids. The purification (15 000-fold) of this enzyme is described. The isolated enzyme is inhibited by o-phenanthroline, which has a similar inhibitory effect on the O2 uptake of cell suspensions with (and without) added amino acids. The basic amino acid oxidase, which is not inhibited by HCN, can be regarded as an 'alternate' oxidase in A. nidulans. An oxidase sensitive to HCN is apparently also operative. At high concentrations of lysine or arginine added HCN can almost double the initial rate of O2 consumption of cell suspensions. This can be attributed to the inhibition of catalase by HCN. At low concentrations of the amino acids, and with more prolonged incubation time, HCN becomes inhibitory. One interpretation could be that the HCN-sensitive terminal oxidase is also involved in the extra O2 uptake elicited by the basic amino acids, but other interpretations are possible. The extra O2 uptake elicited by histidine is almost completely inhibited by HCN, which is consistent with the finding that histidine is a relatively poor substrate for the basic amino acid oxidase.
Nonpenetrating chest injuries often lead to cardiac traumas. Posttraumatic coronary thrombosis with myocardial infarction is shown in two cases. Large anterior aneurysm occured after total occlusion of the descending anterior in both cases. There was no correlation between the severity of the chest injury and the ensuing cardiac damage. An intramural anterior infarction was seen in a third case; because of a normal coronary angiogram an intramyocardial bleeding without coronary thrombosis can be suspected. A direct connection between chest injury and myocardial infarction can only be assumed if there is an onset of symptoms within 24--48 hours after thoracic trauma. A coronary angiogram should be performed in any case of myocardial infarction following chest injury especially in medico-legal cases.
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Actinomycin D, administered to RLC cells which were pretreated with the glucocorticoid dexamethasone phosphate, causes superinduction of tyrosine aminotransferase. By the addition of actidione it could be proved that the superinduction takes place because of the decreased activity of the tyrosine aminotransferase-degrading enzymes.
Once more following the Sophien-Ausgabe of Weimar, Author gives an extract from GOETHE's Letters to literati, scientists, and princes of his time, concerning notices on his employment about sciences without botany. The GOETHE's own words reflect his engagement better than any description from a second hand. Anatomists may take an especial interest in the letters No 1903 to HERDER and No 1904 to CHARLOTTE v. STEIN (both dated the March 27, 1784) which demonstrate the discoverer's mirth in finding out the human os intermaxillare.
This third and last extract from GOETHE's letters between 1818 and 1832 follows the Sophien-Ausgabe of Weimar with the exception of the last two remarks which were drawn from other sources. In 1818, GOETHE riched the 69th year of his life. In this late life-time, he corresponded with scientists, literati, musicians, his son, and his grand-duke CARL AUGUST. The subjects of his correspondence are problems of the scientific investigations' organization as well as of true science, predominantly of paleontology and general morphology including the comparative anatomy.
The results of a 99mTc-DTPA study of vesicoureteral reflux in 51 children with recurrent urinary tract infections were compared with those of radiographic micturition cystourethrography. Reflux, shown by either of the two methods, was regarded as an indication of the disorder. Neither method was regarded as a standard reference method. Agreement between the two methods was obtained in 90 of 102 renal units, i.e., ureter and/or renal pelvis (88%). Statistical analysis performed on the remaining 12 cases showed that the two procedures usually gave similar results.
The formation of HCN from D-histidine in Chlorella vulgaris extracts is shown to be due to the combined action of a soluble protein and a particulate component. Either horse-radish peroxidase (EC 1.11.1.7) or a metal ion with redox properties can be substituted for the particulate component. Ions of manganese and vanadium are especially effective, as are o-phenanthroline complexes of iron. Cobalt ions are less active. The D-amino acid oxidase (EC 1.4.3.3) from kidney and the L-amino acid oxidase (EC 1.4.3.2) from snake venom likewise cause HCN production from histidine when supplemented with the particulate preparation from Chlorella or with peroxidase or with a redox metal ion. The stereospecificity of the amino acid oxidase determines which of the two stereoisomers of histidine is active as an HCN precursor. Though histidine is the best substrate for HCN production, other naturally occurring aromatic amino acids (viz. tyrosine, phenylalanine and tryptophan) can also serve as HCN precursors with these enzyme systems. The relative effectiveness of each substrate varies with the amino acid oxidase enzyme and with the supplement. With respect to this latter property, the particulate preparation from Chlorella behaves more like a metal ion than like peroxidase.
A procedure has been developed for the partial purification from Chlorella vulgaris of an enzyme which catalyzes the formation of HCN from D-histidine when supplemented with peroxidase of a metal with redox properties. Some properties of the enzyme are described. Evidence is presented that the catalytic activity for HCN formation is associated with a capacity for catalyzing the oxidation of a wide variety of D-amino acids. With D-leucine, the best substrate for O2 consumption, 1 mol of ammonia is formed for half a mol of O2 consumed in the presence of catalase. An inactive apoenzyme can be obtained by acid ammonium sulfate precipitation, and reactivated by added FAD. On the basis of these criteria, the Chlorella enzyme can be classified as a D-amino acid oxidase (EC 1.4.3.3). Kidney D-amino acid oxidase and snake venom L-amino acid oxidase, which likewise form HCN from histidine on supplementation with peroxidase, have been compared with the Chlorella D-amino acid oxidase. The capacity of these enzymes for causing HCN formation from histidine is about proportional to their ability to catalyze the oxidation of histidine.
A patient with a cerebro-hepato-renal syndrome was investigated. The visceral manifestations were those of the Zellweger syndrome (ZS); however, the child exhibited muscular hypertonia and survived into the 2nd year of life. Ultramicroscopically, hepatocytes were lacking peroxisomes, but, contrary to findings in one patient with ZS [2], contained smooth endoplasmic reticulum. No catalase was found by histochemistry or spectroscopy. Mitochondria showed normal succinate and glutamate respiration, and normal coupling of respiration to the phosphorylation potential. The cytochrome (cyt) content was diminished to one-third with an abnormally inversed redox pattern of the respiratory chain in the controlled state, cyt b being 5%, cyt c 23% reduced. The oxygen affinity of cyt a3 was normal. These findings exclude a defect in the nonheme iron protein region of the respiratory chain as described in ZS [2], but point to a functional abnormality of cyt b in out patient.
Difficulties in the detection of haemophilia A carriers by the determination of the ratio factor VII coagulation activity to factor VII antigen concentration are shown in part one of our investigations. The second part evaluates methodical parameters of the quantitative immunoelectrophoretic technique. According to our results reliable data can only be obtained under the following conditions: 1. At least three determinations of each sample are required and the mean value should be used as the final result. 2. Each gel plate should be calibrated separately 3. The calibration line should include values less than 100%. Factor VIII concentrates are not suitable for determination of the calibration curve, as higer dilution results in lower calculated concentration of the undiluted concentrate. Storage of pooled normal plasma at--25 degrees C is possible without significant loss of antigen concentration over 5 months. However, plasma samples of a single person show an unpredictable variation in the antigen concentration during storage over the same time.