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Biomedical subjects

B Ludwig

Publications and source records attributed to B Ludwig.

At least 163 records · Page 9Linked to original sources
PubMed1980

Postpartum CT examination of the heads of full term infants.

Intracranial hemorrhage and decreased density of the cerebral parenchyma were the major findings on CT of 150 full term newborns in the first week of life. Clinically silent hemorrhage was rare. All neonates with severe intracranial bleeding had neurological abnormalities. A correlation was not found between hemorrhage and the mode of delivery. The site of hemorrhage and the mode of delivery. The site of hemorrhage has an important bearing on brain development. Periventricular hypodensity is an ambiguous finding which should be interpreted in conjunction with the clinical findings.

Brain↗
PubMed1980

A two-subunit cytochrome c oxidase (cytochrome aa3) from Paracoccus dentrificans.

Cytochrome c oxidase (ferrocytochrome c: oxygen oxidoreductase, EC 1.9.3.1) was purified from the cytoplasmic membrane of the bacterium Paracoccus denitrificans. The enzyme contains two heme groups (a and a3) and two copper atoms per minimal unit, oxidizes mammalian cytochrome c at a high rate, and, when incorporated into liposomes, generates an electrochemical proton gradient during cytochrome c oxidation. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis reveals only two subunits of apparent molecular weights 45,000 and 28,000; they appear to correspond to the two largest mitochondrially made subunits of the seven-subunit cytochrome c oxidase isolated from yeast mitochondria. Because of its structural simplicity. Paracoccus cytochrome c oxidase offers new possibilities for exploring the mechanism of cytochrome c oxidase function.

Amino Acids↗
PubMed1979

Labeling of cytochrome c oxidase with [35S]diazobenzenesulfonate. Orientation of this electron transfer complex in the inner mitochondrial membrane.

Isolated cytochrome c oxidase was fractionated by native-gel electrophoresis in Triton X-100, and a preparation of enzyme almost completely free of the usual impurities was recovered. This fraction was used to generate antibodies specific to cytochrome c oxidase. These antibodies inhibited cytochrome c oxidase activity rapidly and completely and immunoprecipitated an enzyme containing seven different subunits from detergent-solubilized mitochondria or submitochondrial particles. Reaction of detergent-solubilized cytochrome c oxidase with [35S]diazobenzenesulfonate labeled all seven subunits although I and VI were much less reactive than the other five components. When cytochrome c oxidase was immunoprecipitated from mitochondria which had been reacted with [35S]DABS, subunits II and III were the only components labeled. When the complex was immunoprecipitated from labeled submitochondrial particles, II, III, IV, V, and VII were all labeled. Polypeptides I and VI were not labeled from either side of the membrane. These results confirm earlier studies which showed that cytochrome c oxidase spans the mitochondrial inner membrane and is asymmetrically arranged across this permeability barrier.

Animals↗
PubMed1979

Karyotypic variations in human meningioma cell cultures under different in vitro conditions.

Examined were how changes of the culture medium, cultivating procedure and cultivating time will influence numerical representation of different karyotypes in a total of 27 cell cultures of meningiomas with two or more cytogenetically distinguishable cell lines. It could be shown that in medium I (80% Mc Coy 5 A, 20% fetal calf serum) more cell lines with a higher degree of hypodipoidy occurred than in medium II (50% TC 199, 40% bovine amniotic fluid, 10% calf serum). The number of cells with normal karyotype was higher in cultures which were grown from trypsinized biopsy material in stationary flasks when compared to particle cultures in roller tubes. Cells with a normal karyotype also increased after 1--6 subcultures. By demonstration of SV 40 tumor antigen it could be shown in two cultures that these normal mitoses derived from tumoral and not from stromal tissue.

Antigens, Viral↗
PubMed1979

Labeling of complex III, with [35S]diazobenzenesulfonate: orientation of this electron transfer segment in the mitochondrial inner membrane.

[34S]Diazobenzenesulfonate has been used to tag the surface-exposed polypeptides of isolated complex III. All nine different component polypeptides were labeled, indicating that each is at least partially exposed on the surface of the isolated, detergent-dispersed complex. Labeling studies were also conducted on the membrane-bound complex. Preparations of intact mitochondria and submitochondrial particles were separately labeled with [35S]diazobenzenesulfonate in order to determine the distribution of the polypeptides of complex III between the outer (cytoplasmic) and inner (matrix) surfaces of the mitochondrial inner membrane, respectively. Polypeptides II and III were the only components labeled in a significant amount in submitochondrial particles (i.e., from the matrix side). Polypeptides III, IV, and VI were heavily labeled in mitochondria (i.e., from the cytoplasmic side). Polypeptides I,II, V, and VII were also labeled in mitochondria but to a much lesser extent. Polypeptides VIII and IX were not significantly labeled from either side of the membrane. The labeling data and information obtained from previous crosslinking studies [Smith, R.J. & Capaldi, R.A. (1977) Biochemistry 16, 2629-2633] are used to derive a picture of the arrangement of complex III in the mitochondrial inner membrane.

Animals↗
PubMed1978

[Organic lesions after application of hashish in rats and rabbits (author's transl)].

Toxic lesions were found in liver, kidney and brain of rats and rabbits after oral application of hashish for 7 or 30 days. The brain tissue showed hyperemia and edema. The cerebral cortex, brain stem and cerebellum contained ganglion cells with eccentric nuclei and an icreased number of nucleoli. Different stages of cell lesions could be distinguished by nuclear vacuoles, pyknosis and karyolysis. The cytoplasma was loosened and showed numerous vacuoles. In the kidney we found, besides interstitial hemorrhage, cloudy swelling of the proximal tubules with vacuolous degeneration and nuclear pyknosis and karyolysis in all stages. The glomeruli were often enlarged with thickening of Bowman's capsule and surrounding cellular infiltration with cell fragments. The liver cells showed irregularities of nuclei and vacuolated nuclei, plasma vacuoles and cell necrosis. Infiltrations of round cells at the portal-biliary areas were usually combined with an activation of the Kupffer cells and intracellular bile stasis.

Adenosine Triphosphatases↗
PubMed1978

[Contribution to the diagnosis of cortical atrophy: evaluation of computer tomograms and angiograms of patients over 70 years old (author's transl)].

To find evidence of cortical atrophy, 112 computer tomograms and 40 angiograms of patients above the age of 70 were evaluated. In the CT the width of the interhemispheric and of the sylvian fissure, in the angiograms the distance between the vessels extending into the interhemispheric fissure (anteroposterior view) and the distance between the cortical branches and the inner table (lateral view) were measured. The same measurements were performed in 100 normal computer tomograms and in 100 normal angiograms of patients between 20 and 40 years old. Statistically significant differences could be ascertained between the mean values for the patients over 70 and those for the younger ones, indicating that age-induced cerebral atrophy can be neuroradiologically demonstrated. The radiologic findings, however, do not necessarily correspond to the grade of intellectual impairment in the elderly. Neuropathologic and molecular biological research could bring us closer to the solution of this correlative problem.

Adult↗
PubMed1978

[Suction technic and suction method in dental practice].

By way of introduction the authors deal with the necessity for suction as an important component of ergonomic work organization in dental practice. The technical pre-conditions (suction technique) are indicated. Principles are formulated for their beneficial application in the sense of systematic suction methodics.

Dental Equipment↗
PubMed1976

Plant microbody proteins. II. Purification and characterization of the major protein component (SP-63) of peroxisome membranes.

The major component of membranes of microbodies from green leaves of Lens culinaris is a protein of a subunit molecular weight of 63 000. This protein, referred to as SP-63, seems to be unique to microbodies and could not be detected when plastids or mitochondria were analyzed. It is probably a structural protein and is thus not solubilized by cholate, Triton X-100, chloroform/methanol, or 0.2M KCl. Solubilization from purified membranes was achieved with guanidinium chloride or sodium dodecylsulphate. The protein was separated from minor contaminating components by chromatography on Sepharose 4B or Sephadex G-150 employing 0.1% sodium dodecylsulphate or 4M urea as eluent. It was shown to be homogeneous upon sodium dodecylsulphate gel electrophoresis and did not give a positive glycoprotein stain.

Guanidines↗
PubMed1976

Plant microbody proteins, III. Labelling of the peroxisomal membrane protein SP-63 in vitro and in vivo.

Methods were developed to charcterize membranes and membrane components of leaf peroxisomes from Lens culinaris. While microbodies from etiolated young leaves exhibited an equilibrium density of 1.19 g/cm3, older leaves or leaves exposed to light for increasing periods of time contained microbodies banding at higher densities up to 1.235 g/cm3. Similar values were also found for the corresponding microbody membranes, which could be labelled with diazotized [35S]sulphanilic acid. Labelling was also performed using proteins extracted from the membranes. Their main structural protein (SP-63) was solubilized with sodium dodecylsulphate and labelled with fluorescent compounds as well as with diazotized [35S]sulphanilic acid or [3H]iodoacetic acid. These conversions greatly facilitate all analytical procedures, e.g. tracing the migration of SP-63 in gels or the movement in sucrose gradients containing sodium dodecylsulphate during zonal centrifugation. Also, labelling of SP-63 in vivo was accomplished when labelled amino acids were infused into etiolated leaves while exposing them to light.

Darkness↗
PubMed1975

Enhancement of immunity against murine syngeneic tumors by a fraction extracted from non-pathogenic mycobacteria.

The data reported here demonstrate that a preparation extracted from nonpathogenic mycobacteria such as Mycobacterium smegmatis and hereafter referred to as interphase material protected mice against Ehrlich ascitic carcinoma, L-1210 leukemia, and another syngeneic lymphoid leukemia. Furthermore, mice treated by this preparation were much less susceptible to endotoxins than when stimulated by BCG (bacillus Calmette-Guerin) or M. smegmatis cells. Moreover, guinea pigs treated by interphase material administered in Freund's incomplete adjuvant showed an increased immune response, yet their sensitivity to tuberculin was much weaker than that of controls sensitized with Freund's complete adjuvant. Finally, resistance to Columbia SK virus infection could be demonstrated when interphase material was administered to mice prior to virus challenge.

Adjuvants, Immunologic↗