E codes and injury surveillance: Part 2.
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Emergency Service, Hospital↗
Biomedical subjects
H Weiss
Publications and source records attributed to H Weiss.
Escherichia coli NADH dehydrogenase I, a minimal form of the mitochondrial complex I.
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Amino Acid Sequence↗
[Are there metastatic angiomyolipomas?].
An angiomyolipoma is now mostly diagnosed by sonography due to sonographically typical criteria, such as abundant echoes and clear delineation, or via CT, since it is a process rich in fat and hence hypodense. Laying bare by surgery will only be required in case of an atypical localisation or expansive tumour growth. Two case reports are presented with ipsilateral lymph node infiltration in multifocal angiomyolipoma and expansion of the tumour into the vena cava via the renal vein.
Adult↗
Molecular analysis of rat embryo cell transformants induced by alpha-particles.
An immortal cell line was established by transfecting a myc oncogene into rat embryo cells (REC:myc). This cell line was diploid, contact inhibited and grew well in culture. Exposure to a single 200 cGy dose of 6 MeV alpha-particles transformed these cells with a frequency of focus formation of approximately 3.6 x 10(-4) compared with a transformation frequency of < 7.8 x 10(-6) for primary cultures of REC. Isolates of alpha-particle-induced REC:myc (REC:myc:alpha) foci displayed anchorage-independent growth in soft agar and were tumourigenic in nude mice. Molecular studies demonstrated no alteration of gene structure or expression of the transfected or of the endogenous c-myc genes. Similarly, there was no alteration of the structure of Ha-ras, Ki-ras, or N-ras. The expression of Ha-ras, Ki-ras, N-ras and raf was not altered significantly. Assay for dominant oncogenes via DNA-mediated gene transfer into NIH3T3 cells was positive for nine of 13 REC:myc:alpha transformants. All NIH3T3 isolates contained bands hybridizing to rat repetitive DNA. NIH3T3 transformants from a tertiary round of transfection were analysed by Southern blot analysis for the presence of Ki-ras, N-ras, raf, trk, abl, fms, src, mos, fos, sis, fps, erbA, erbB or neu oncogenes of REC origin, and none were detected. Tertiary NIH3T3 transformants from three REC:myc:alpha transformants contained bands corresponding to Ha-ras but no point mutations were identified at the known hotspots of exons 1 or 2 of the donor REC:myc:alpha transformants. The inactivation of the tumour suppressor genes Rb, and p53, and the anti-metastasis gene, nm23, was evaluated by Southern and Northern hybridization analysis. Southern blots demonstrated that at least one allele of Rb, p53 and nm23 was present and no large scale structural changes were detected. No expression of Rb or p53 was detected in REC:myc or the alpha-particle-induced REC:myc transformants. The expression of nm23 was not altered in the transformed cell lines. While the analysis of the role of tumour suppressor gene inactivation in radiation-induced cell transformation is only in the initial stages, the results of DNA-mediated gene transfer into NIH3T3 cells suggest that unidentified dominant oncogenes are associated with alpha-particle-induced transformation in vitro.
Alpha Particles↗
Electron transfer complexes I and IV of platelets are abnormal in Parkinson's disease but normal in Parkinson-plus syndromes.
Using a technique which requires only 100 ml blood we investigated the electron transfer complexes (ETC) I, III and IV in platelet mitochondria of 44 control subjects, 27 patients with idiopathic Parkinson's disease and eight patients with Parkinson-plus syndromes due to multiple system atrophy. In both control subjects and patients, ETC measurements were repeated at intervals of several months. The activities varied considerably among normal subjects, but intra-individual variation of ETC activities were low at repetitive measurements. In normal subjects there was no correlation between enzyme activities and age or training state. There was no difference in enzyme activities between smokers and non-smokers in the control group. Complex I activity was lower in Parkinson's disease patients than in controls (14 versus 29 nmol/min/mg platelet protein; P < 0.001). Furthermore, the group difference in complex IV activity also reached statistical significance (83 versus 58 nmol/min/mg platelet protein; P < 0.001). Additionally, in some Parkinson's disease patients, activities of complex III were low and lay outside the control range, but the group difference did not reach significance. There was no correlation between complex I activity and disease duration or severity as well as the daily L-dopa dose in Parkinson's disease patients. Repeated measurements in five Parkinson's disease patients in the earliest stages of their illness demonstrated that the decrease in complex I and IV activities can develop rapidly within 1 year. In Parkinson-plus patients suffering from multiple system atrophy the ETC activities were normal.
Aged↗
Effects of anesthesia on micturition and urodynamics.
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Anesthetics↗
[The layers of the gallbladder wall: an ultrasound-anatomic comparative study].
In a sonographic-histological comparative test, operatively withdrawn gallbladders in native and formol-fixed states were examined. The thickness of the gallbladder wall and of its layers was measured sonographically. Afterwards the gallbladders were reexamined microscopically in the sonographic sectional plane and the measurement was repeated. By removal of the single layers of the wall and by repeated sonographic measuring, sonographic and microscopic measurements of the parietal layers could be correlated. Both gallbladder wall thickness and thickness of the single anatomic layers can be evaluated sonographically. The correlation between sonographic and histological measurements is fairly to highly significant. The sonographically measurable layers can be related to the following anatomical layers (when measuring from outwards to inwards): 1. echogenic layer = initial echo and subserosa; 2. echo-poor layer = muscularis; 3. echogenic layer = lamina propria; 4. echo-poor layer = mucosal epithelium; 5. echogenic layer = exit echo.
Cholecystectomy↗
Which organ preservation solution best protects vascular endothelium?
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Adenosine↗
IgE response in multiple myeloma.
IgE levels in sera of patients with multiple myeloma (MM) were found to be similar to those of patients with monoclonal gammopathy of unknown significance (MGUS) and to normal controls. This is in contrast to the significant depression in the level of the other polyclonal isotypes in patients with MM. Immediate skin test response to common environmental allergens was also preserved in patients with MM as compared with normal nonatopic controls. One-year treatment of MM patients with alkylating agents caused a significant decrease in the monoclonal immunoglobulin level and induced a tendency toward decreasing IgE level but had no effect on the polyclonal immunoglobulin concentrations. These findings suggest that IgE production and immediate skin test response is not impaired by the pathologic process in MM patients, in contrast to the production of other polyclonal immunoglobulins. This demonstrates the dissociation between the response of the IgE antibody and the other isotypes.
Aged↗
[Psychosomatic and somatopsychic aspects of myasthenia gravis. A critical review of the literature].
In an extensive literary abstract the up to now existing scientific research strategies and results concerning the psychosomatics of myasthenia gravis are introduced. While the pioneers of myasthenia-research already registered psychological disorders that were separated from differential diagnostic conversion neurosis, new studies show the noticeable high prevalence of psychopathological symptoms in myasthenia-patients. Besides monistic-somatic models, psychosomatic attempts of explanation were put forth in the past. Authors seem to agree at least with regard to psychological factors being able to influence symptom manifestation and course on a casuistic basis. Somatopsychic interdependencies seem to be of more significance, as it is stressed by coping-research. However controlled longitudinal studies lack yet, so far as to what degree psychosocial and somatic factors are clinically relevant with regard to coping with the disease. Perspectives for future research are given finally.
Adaptation, Psychological↗
Accumulation of the pre-assembled membrane arm of NADH:ubiquinone oxidoreductase in mitochondria of manganese-limited grown Neurospora crassa.
The NADH:ubiquinone oxidoreductase (complex I) of mitochondria is constructed from two arms arranged perpendicular to each other. The peripheral arm protruding into the matrix contains the proximal section of the electron pathway, and the membrane arm with all mitochondrially encoded subunits contains the distal section of the electron pathway. When Neurospora crassa is grown under manganese limitation the formation of the peripheral arm is disturbed, but the membrane arm containing the iron-sulfur cluster N-2, is accumulated. An extra-polypeptide, assumed to be a chaperone, is found to be associated with this pre-assembled membrane arm.
Electron Spin Resonance Spectroscopy↗
Primary structure and mitochondrial import in vitro of the 20.9 kDa subunit of complex I from Neurospora crassa.
The 20.9 kDa subunit of NADH:ubiquinone oxidoreductase (complex I) from Neurospora crassa is a nuclear-coded component of the hydrophobic arm of the enzyme. We have determined the primary structure of this subunit by sequencing a full-length cDNA and a cleavage product of the isolated polypeptide. The deduced protein sequence is 189 amino acid residues long and contains a putative membrane-spanning domain. Striking similarity over a 60 amino-acid-residue domain with the M (matrix) protein of para-influenza virus was found. No other relationship with already known sequences could be detected, leaving the function of this subunit in complex I still undefined. The biogenetic pathway of this polypeptide was studied using a mitochondrial import system in vitro. The 20.9 kDa subunit synthesized in vitro is efficiently imported into isolated mitochondria, where it obtains distinct features of the endogenous subunit. Our results suggest that the 20.9 kDa polypeptide is made on cytosolic ribosomes lacking a cleavable targeting sequence, interacts with the mitochondrial outer membrane (in a process that does not require an energized inner membrane), and is imported into mitochondria at contact sites. The 20.9 kDa subunit is then inserted into the inner membrane acquiring a topology similar to that of the already assembled subunit.
Amino Acid Sequence↗
Characterization of assembly intermediates of NADH:ubiquinone oxidoreductase (complex I) accumulated in Neurospora mitochondria by gene disruption.
NADH:ubiquinone oxidoreductase, the respiratory chain complex I of mitochondria, is an assembly of some 25 nuclear-encoded and 7 mitochondrially encoded subunits. The complex has an overall L-shaped structure formed by a peripheral arm and an elongated membrane arm. The peripheral arm containing one FMN and at least three iron-sulphur clusters constitutes the NADH dehydrogenase segment of the electron pathway. The membrane arm with at least one iron-sulphur cluster constitutes the ubiquinone reducing segment. We are studying the assembly of the complex in Neurospora crassa. By disrupting the gene of a nuclear-encoded subunit of the membrane arm a mutant was generated that cannot form complex I. The mutant rather pre-assembles the peripheral arm with all redox groups and the ability to catalyse NADH oxidation by artificial electron acceptors. The final assembly of the membrane arm is blocked in the mutant leading to accumulation of complementary assembly intermediates. One intermediate is associated with a protein that is not present in the fully assembled complex I. The results demonstrate that the two arms of complex I are assembled independently on separate pathways, and gave a first insight into the assembly pathway of the membrane arm. It is also shown for the first time that the obligate aerobic fungus N. crassa can grow and respire without an intact complex I. Gene replacement in this fungus is therefore a tool for investigation of this complex.
Blotting, Southern↗
De novo synthesis and desaturation of fatty acids at the mitochondrial acyl-carrier protein, a subunit of NADH:ubiquinone oxidoreductase in Neurospora crassa.
We have cultivated the cel mutant of Neurospora crassa defective in cytosolic fatty acid synthesis with [2-14C]malonate and found radioactivity covalently attached to the mitochondrial acyl-carrier protein (ACP), a subunit of the respiratory chain NADH:ubiquinone oxidoreductase. We purified the ACP by reverse-phase HPLC: the bound acyl groups were trans-esterified to methylesters and analyzed by gas chromatography. The saturated C6 to C18 fatty acids and oleic acid were detected. De novo synthesis and desaturation of fatty acids at the ACP subunit of NADH:ubiquinone oxidoreductase and use of the products of this mitochondrial synthetic pathway for cardiolipin synthesis is discussed.
Acyl Carrier Protein↗
Non-linear inhibition curves for tight-binding inhibitors of dimeric ubiquinol-cytochrome c oxidoreductases. Evidence for rapid inhibitor mobility.
Steady-state electron flow through and electron delivery into isolated dimeric bc1 complex (ubiquinol--cytochrome c oxidoreductase) from Neurospora crassa and beef heart mitochondria were studied in the presence of increasing concentrations of antimycin A, funiculosin and/or myxothiazol. Parabolic or linear inhibition curves were obtained, depending upon the different quinols and inhibitors that were used. Linear curves occur when the inhibitor directly affects the rate-determining step. The most reasonable explanation for the parabolic curves is given by a fast intradimeric exchange of the hydrophobic inhibitors antimycin A, funiculosin (rate less than 500 s-1) and of myxothiazol (rate greater than 1 s-1). Using mitochondria from beef heart, the shape of the inhibition curve with antimycin A is parabolic if the quinol--O2 oxidoreductase turns over at about 300 s-1, but hyperbolic if the rate is 5 times less. The hyperbolic titration curve may be the result of both intradimeric and an additional interdimeric redistribution (rate approximately 100 s-1) of inhibitors between enzymes incorporated in a continuous phospholipid membrane. This explanation is supported by experiments with chromatophores obtained from Rhodobacter capsulatus. As recently described [Fernandez-Velasco, J. & Crofts, A. R. (1992) Biophys. J. 2, A153], cytochrome b becomes fully reoxidized within 1 s after a flash at substoichiometric concentrations of antimycin A. This kinetic of the slow reoxidation can be expressed in terms of the intradimeric and interdimeric redistribution with rate constants of about 10 s-1 and 2 x 10(6) M-1 s-1, respectively. It seems that rapid inhibitor redistribution may be a widespread phenomenon for hydrophobic inhibitors of enzymes incorporated in lipid membranes.
Animals↗
Effect of calcium channel antagonists on cell membrane potential oscillations and proliferation of cells expressing the ras oncogene.
NIH fibroblasts expressing the Ha-ras oncogene (+ras), unlike otherwise identical cells not expressing the oncogene (-ras), are able to grow in serum-depleted media (0.5% fetal calf serum). Electrophysiological experiments revealed that in +ras fibroblasts but not in -ras fibroblasts, bradykinin leads to sustained, calcium-dependent oscillations of cell membrane potential by repetitive activation of calcium-sensitive K+ channels, resulting from oscillating intracellular calcium activity. The present study was performed to test for an effect of calcium channel antagonists on these phenomena. Whereas 10 mumol/l verapamil and 10 mumol/l diltiazem did not significantly interfere with either oscillations or proliferation, 10 mumol/l nifedipine completely abolished both the oscillations and the proliferation of +ras fibroblasts. The number of -ras fibroblasts remained virtually constant in both the presence and absence of 10 mumol/l nifedipine. These observations show the antiproliferative action of nifedipine and suggest that the oscillations of cell membrane potential are pertinent for the proliferation of +ras cells in serum-depleted media.
3T3 Cells↗
Electron transfer complex I defect in idiopathic dystonia.
It has been suggested that dystonia is caused by an autosomal gene with reduced penetrance and a consequent biochemical abnormality affecting cell activity within the basal ganglia. No consistent biochemical disturbance has been identified. In the present study, activities of the mitochondrial electron transfer complexes were measured in platelets of 31 patients with idiopathic dystonia. Enzyme assays of these patients were compared to measurements in 28 control subjects. A significant decrease of complex I activity was observed in the majority of the patients, whereas the activities of other electron transfer complexes were normal. The severity of the complex I defect was more pronounced in patients with the segmental or generalized form than in those with focal dystonia. Complex I activity was not age dependent in the patients or control subjects. Although the electron pathway in complex I is disturbed in patients with idiopathic dystonia, complex I protein content seems to be normal. Whether abnormalities of complex I activity play a role in the pathogenesis of idiopathic dystonia remains to be determined.
Adult↗
Ion channels activated by swelling of Madin Darby canine kidney (MDCK) cells.
According to previous studies hyposmotic swelling of Madin Darby Canine Kidney (MDCK) cells leads to a marked decrease of cell membrane resistance. The present study has been performed to identify the underlying ion channels using the patch-clamp technique: reduction of extracellular osmolarity to 230 mmol/liter leads to a transient activation of K+ channels and a sustained activation of anion channels. The K+ channels are inwardly rectifying with a single-channel slope conductance of 56 +/- 3 pS at -50 mV (cell negative) and of 29 +/- 2 pS at 0 mV PD across the patch (150 mmol/liter K+ in pipette). The same channels are activated by an increase of intracellular calcium activity, as shown previously. The anion channels display a single-channel slope conductance of 41 +/- 4 pS at -50 mV (cell negative) and of 25 +/- 3 pS at 0 mV PD across the patch (150 mmol/liter Cl- in pipette). The channel is anion selective and conducts both bicarbonate and chloride with a preference for bicarbonate. Its open probability is not affected by changing intracellular calcium from 0.1-10 mumol/liter. The channels observed explain the effects of cell swelling on PD, ion selectivity and resistance of the cell membrane in MDCK cells.
Animals↗