[A 35-year-old female patient with fever, thrombocytopenia, massive organ hemorrhage, kidney failure and severe neurologic disorders].
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Adult↗
Biomedical subjects
B Ludwig
Publications and source records attributed to B Ludwig.
Cytochrome c1 from Paracoccus denitrificans.
Cytochrome c1 was purified from the bacterium Paracoccus denitrificans. It is an acidic, hydrophobic polypeptide with an apparent molecular weight of around 65000 and a single, covalently attached heme; it cross-reacts immunologically with cytochrome c1 from yeast mitochondria. The amino acid sequence of the tryptic heme peptide of the bacterial cytochrome c1 shows extensive homology to the corresponding region of beef heart cytochrome c1 [Wakabayashi, S. et al. (1982) J. Biol. Chem. 257, 9335-9344]. Positive evidence for a stable association of the Paracoccus cytochrome c1 with other polypeptides and b-type heme components ('bc1-complex') has not yet been obtained.
Amino Acid Sequence↗
Sequence homology of bacterial and mitochondrial cytochrome c oxidases. Partial sequence data of cytochrome c oxidase from Paracoccus denitrificans.
The aerobic electron transport chain of Paracoccus denitrificans is very similar to that of mitochondria. It has therefore been suggested that this bacterium might be evolutionarily related to mitochondria. The two subunits (Mr 45.000 and 28.000) of the Paracoccus cytochrome c oxidase were isolated and partially sequenced. The sequences were found to be surprisingly homologous to sequences of the subunits I and II of mitochondrial cytochrome c oxidases. The data provide a molecular basis for the symbiotic origin of mitochondria and strongly support the notion that in eucaryotic oxidases subunits I and/or II carry the redox centers, heme and copper.
Amino Acid Sequence↗
Dicyclohexylcarbodiimide does not inhibit proton pumping by cytochrome c oxidase of Paracoccus denitrificans.
The effect of dicyclohexylcarbodiimide (DCCD) on the proton pumping two-subunit cytochrome c oxidase from Paracoccus denitrificans was investigated. Purified Paracoccus oxidase was reconstituted into phospholipid vesicles by cholate dialysis. Following incubation with increasing amounts of DCCD, proton ejection was recorded in response to reductant pulses with reduced cytochrome c. Concentrations of DCCD which greatly reduced proton pumping by bovine cytochrome c oxidase used as a control were found to exert only a minor effect on proton translocation by Paracoccus oxidase. Similarly, incubation of the bacterial enzyme with [14C]DCCD failed to reveal the specific covalent interaction previously demonstrated to occur with bovine cytochrome c oxidase, and here also shown for the oxidase of yeast. Thus, Paracoccus oxidase differs in its interaction with DCCD from the functionally analogous eukaryotic enzymes.
Animals↗
Computed tomography of the "armored brain".
A calcified chronic subdural hematoma may cover the surface of the cerebral hemispheres to such an extent that one can talk of an "armored brain". Pathogenesis, clinical course and treatment are discussed based on the computed tomograms of five cases.
Adolescent↗
[Viral myocarditis: symptomatology, clinical diagnosis and hemodynamics].
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Female↗
Purification and characterization of the cytochrome c oxidase from Rhodopseudomonas sphaeroides.
When grown aerobically in the dark, Rhodopseudomonas sphaeroides develops a respiratory chain similar to that in mitochondria and the photosynthetic apparatus is suppressed. The aa3-type cytochrome c oxidase from Rps. sphaeroides has been purified in Triton X-100 by affinity chromatography with Sepharose 4B coupled to yeast cytochrome c. The oxidase contains 14 nmol heme a/mg protein and is composed of three polypeptide subunits with relative molecular masses of 45000, 37000 and 35000. The enzyme is highly active in the presence of detergents, with a maximal velocity of 300 s-1/mol oxidase using either yeast or horse-heart cytochrome c. The Rps. sphaeroides oxidase is cross-reactive with antibodies directed against the oxidases from Paracoccus denitrificans and Saccharomyces cerevisiae. A particularly close relationship is indicated in the case of P. denitrificans. The Rps. sphaeroides oxidase has been incorporated into phospholipid vesicles. The resulting oxidase in these vesicles demonstrates high enzymatic activity and a respiratory control ratio of 5. Using these vesicles, no evidence for proton extrusion accompanying cytochrome c oxidation was observed. The data suggest that the Rps. sphaeroides oxidase does not function as a proton pump.
Bacterial Proteins↗
Solubilized cytochrome c oxidase from Paracoccus denitrificans is a monomer.
Cytochrome c oxidase purified from the bacterium Paracoccus denitrificans was analyzed by analytical ultracentrifugation. In the detergent octyltetra/pentaoxyethylene (C8E45), the isolated enzyme exhibits a molecular weight of 79,000 to 84,000. The detergent-solubilized enzyme is thus a monomer which contains one copy of each of the two subunits.
Detergents↗
The cytochrome c oxidase of Paracoccus denitrificans pumps protons in a reconstituted system.
The purified two-subunit cytochrome c oxidase of Paracoccus denitrificans was reconstituted into phospholipid vesicles having a high internal buffering capacity and exhibiting a respiratory control index greater than 6.6. With these proteoliposomes, pH changes of the suspending medium were monitored in response to reductant pulses in the presence of valinomycin and potassium. When reduced cytochrome c was added to allow for a limited number of turnovers (2-12), a net acidification of the extravesicular space could be observed. This apparent proton ejection by the vesicles was abolished by inhibition of the oxidase with azide, by bypassing the oxidase with ferricyanide, or by preventing charge compensation by omitting valinomycin. Addition of uncoupler led to an alkalinization, rather than an acidification, of the extravesicular space in response to reduced cytochrome c. We thus conclude that cytochrome c oxidase of P. denitrificans is a proton pump. Under the conditions described here, an apparent stoichiometry of 0.6 proton ejected/electron was obtained by extrapolation to zero turnovers.
Animals↗
Reduced risk of ICA ligation after balloon occlusion test.
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Adult↗
[Immunological examinations in dilated cardiomyopathies].
Immunological data in dilated cardiomyopathies can differentiate the nosology of these diseases. In nearly one half of these dilated cardiomyopathies, binding of immunoglobuline in myocardial structures (biopsies) can be demonstrated. By immunohistological techniques collagen I in myocardial biopsies has been predominantly shown. In lymphocytes of the diseases patients the T-cell-suppressor activity is low. This phenomenon seems to play an important role in the pathogenesis of dilated cardiomyopathies and can explain numerous humoral immunological findings. As conclusion the hypothesis can be drawn: several cases of dilated cardiomyopathies and myocarditis can be regarded as different stages of a single underlying disease, in which a low T-cell-suppressor activity seems to act as a predisposing factor.
Antibody Formation↗
Reaction of oxygen with cytochrome c oxidase from Paracoccus denitrificans.
The reaction of reduced cytochrome c oxidase (EC 1.9.3.1) from Paracoccus denitrificans (American Type Culture Collection 13543) with dioxygen has been followed by laser flash photolysis of the CO derivative. In detergent-stabilized solutions the reaction showed at least two distinct kinetic components, the faster of which was oxygen concentration dependent and had a rate of approximately 60 X 10(6) M-1 s-1. The slower reaction was independent of oxygen concentration and had a rate of 9 X 10(2) s-1. These rates are about 1.5 times greater than comparable rates for ox heart oxidase reported by C. Greenwood and Q. H. Gibson (J. Biol. Chem. (1967) 242, 1782-1787). The kinetic components have markedly different optical spectra which agree precisely in form with those for ox heart enzyme (Greenwood, C., and Gibson, Q. H. (1967) J. Biol. Chem. 242, 1782-1787) but are shifted by 2 nm toward the red. In phospholipid vesicles, the spectral contribution of the faster component was augmented. The dissociation constant for CO at 20 degrees C is 1.6 microM, 6 times greater than for the ox heart enzyme. The bacterial enzyme binds one CO per 2 heme a. The enzyme has an absorption band at 830 nm in the oxidized form similar to that of the ox heart enzyme.
Carbon Monoxide↗
[Ergometric dose-effect study of bunitrolol (Stresson) in patients with coronary heart disease (author's transl)].
20 patients with coronary heart disease and ergometrically provocable stenocardias and electrocardiographic signs of ischemia were tested ergometrically with two different dosages (5 mg:20 mg) of the beta-blocking agent bunitrolol (Stresson) in a double-blind-test. The results obtained are in accordance with literature: The greater the ergometric stress the more effective is Stresson and vice versa. For treatment of coronary heart disease can be considered: Low dosage of Stresson in patients with stenocardias and hypoxias in high-grade exercise, high dosage of Stresson in patients with stenocardias or ischemias in low-grade exercise or rest.
Clinical Trials as Topic↗
Central nervous system involvement in Whipple's disease.
A case of Whipple's disease is presented manifesting itself predominantly with neurological and mental symptoms but without gastrointestinal complaints. Although the first cranial CT in the fourth year of the disease was normal, the second, 1.5 years later, revealed intensive hypodensity of the white matter and cortical enhancement. CT findings are compared with autopsy results and a review of the pertinent literature is given.
Adult↗
Copper and manganese electron spin resonance studies of cytochrome c oxidase from Paracoccus denitrificans.
The two-subunit cytochrome c oxidase from Paracoccus denitrificans contains two heme a groups and two copper atoms. However, when the enzyme is isolated from cells grown on a commonly employed medium, its electron paramagnetic resonance (EPR) spectrum reveals not only a Cu(II) powder pattern, but also a hyperfine pattern from tightly bound Mn(II). The pure Mn(II) spectrum is observed at -40 degrees C; the pure Cu(II) spectrum can be seen with cytochrome c oxidase from P. denitrificans cells that had been grown in a Mn(II)-depleted medium. This Cu(II) spectrum is very similar to that of cytochrome c oxidase from yeast or bovine heart. Manganese is apparently not an essential component of P. denitrificans cytochrome c oxidase since it is present in substoichometric amounts relative to copper or heme a and since the manganese-free enzyme retains essentially full activity in oxidizing ferrocytochrome c. However, the manganese is not removed by EDTA and its EPR spectrum responds to the oxidation state of the oxidase. In contrast, manganese added to the yeast oxidase or to the manganese-free P. denitrificans enzyme can be removed by EDTA and does not respond to the oxidation state of the enzyme. This suggests that the manganese normally associated with P. denitrificans cytochrome c oxidase is incorporated into one or more internal sites during the biogenesis of the enzyme.
Animals↗
[Studies on the incidence of intracranial haemorrhages and their relation to the delivery by using the cranial computer-tomography (CT) in full-term newborns].
The cranial computer-tomography is a new non-invasive method for the diagnosis of perinatal intracranial haemorrhage. Among 80 neonates, who were examined by CT after delivery at term between the 3rd and 5th day of life, there were 43 newborns without any neurological symptom. These were examined voluntarily with the permission of their parents. A significant correlation between the CT-finding of an intracranial haemorrhage and the neurological observations was found, whereas there was no relation to the mode of delivery. Parity, birth weight, Apgar-score, cord blood-pH did not correspond to the CT-findings. An extremely short duration of the second stage of labor in spontaneous delivery seems to increase the risk of perinatal intracranial haemorrhage.
Apgar Score↗
[Ergometric double-blind study, Isoket-spray versus placebo-spray, in patients with coronary heart disease (author's transl)].
In a double-blind study 40 patients with coronary heart disease, who all complained of typical exertion-dependent angina pectoris symptoms and showed ECG changes after work in conformity with a myocardiac hypoxia, were examined in ergometric exertion tests before as well as immediately and 60 minutes after a single dose of 3.75 mg of Isoket-spray or Placebo-spray respectively. The Isoket-spray group was compared with the placebo group, furthermore, within the Isoket-spray group, the original ergometry (without medication) and the subsequent ergometries. The ST-depression, the time until reattainment of the original electrocardiographical situation after cessation of exertion and the subjective complaints showed highly significant improvements after use of the Isoket-spray in both repeated ergometries. Rapid and long-term relief after application of Isoket-spray were thus impressively shown in this double-blind study.
Aerosols↗
[Acebutolol in coronary heart disease: an ergometric double-blind study (author's transl)].
In 20 patients with coronary heart disease and typical changes in the exercise ECG (evidence of myocardial hypoxia), which disappeared completely on second ergometry after isosorbid dinitrate, the effect of a single dose of 400 mg acebutolol (Prent) was tested on exercise. Ergometrically induced cardiac work was significantly reduced in all patients, compared with leg exercise (little change in lower, more marked change in the higher ranges of exercise) so that repeat ergometry at the same ergometric level of exercise produced neither signs of hypoxia nor angina. There were no significant changes after a placebo.
Acebutolol↗