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PubMed1991

[Evaluation of left ventricular systolic function reserve before and after percutaneous transluminal coronary angioplasty by isometric exercise Doppler and two-dimensional echocardiography].

Left ventricular systolic function reserve (LVSFR) was assessed by isometric exercise Doppler and two-dimensional echocardiography before and after percutaneous transluminal coronary angioplasty (PTCA) in 28 patients with coronary artery disease. Pulsed Doppler echocardiograms were obtained from the sample volume which was placed just below the aortic valve in the apical long-axis view. Three parameters, including peak velocity (PV), acceleration time (AT), and mean acceleration (ACC), were measured before and at the end of 2 min-handgrip exercise. The area reduction rate (AR) was calculated from the two-dimensional echocardiograms at the level of the papillary muscle in the short-axis view obtained at rest and at the end of exercise. Percent changes of these 4 parameters (%PV, %AT, %ACC, %AR) from at rest to the end of exercise were also calculated before and after PTCA. No significant changes were detected in PV, AT, ACC and AR at rest, before and after PTCA. Percent changes of PV, ACC, and AR increased significantly (p < 0.01), while those of AT decreased significantly after PTCA (p < 0.01). Our method proved to be useful for assessing LVSFR in coronary artery disease and the findings obtained using this method suggested that LVSFR can be alleviated by successful PTCA.

Aged↗
PubMed1994

Active site geometry in the high oxido-reduction potential rusticyanin from Thiobacillus ferrooxidans.

Rusticyanin is a blue copper protein involved in the oxidation of iron catalyzed by Thiobacillus ferrooxidans. This protein is characterized by a high oxido-reduction potential and a high stability at low pH. The three dimensional structure of this protein is still unknown and in order to investigate the geometric properties of the copper center which could be correlated to the high oxido-reduction potential, we have studied rusticyanin by UV-Visible, EPR and NMR spectroscopies, at different pH values. Our results suggest that rusticyanin is stable between pH 2 and pH 9 and that the copper center does not undergo significant geometric modifications in this pH range. Moreover, the copper atom could be buried more deeply in the protein than in other type I copper proteins and the atomic distance Cu-S(Met), one of the four bonds involved in copper coordination, is probably shorter in rusticyanin than in other cupredoxins. These two properties of the copper site are expected to be responsible, in part, for the high oxido-reduction potential observed in rusticyanin.

Azurin↗
PubMed1990

Single, total paracentesis for tense ascites: sequential hemodynamic changes and right atrial size.

Hemodynamic changes induced by a single, total paracentesis were evaluated in 21 patients with tense ascites from whom 4 to 16 L of ascites were drained over 2 to 8 hr with no serious complications. At 60 min, compared to baseline, there was an increase in cardiac output (7.7 +/- 0.5 to 8.5 +/- 0.6 L/min, p less than 0.02) and a tendency for right atrial pressure to decrease (9.3 +/- 0.8 to 7.50 +/- 0.8 mm Hg, NS), with no change in pulmonary capillary wedge pressure (10.9 +/- 0.9 to 10.7 +/- 0.9 mm Hg). Between 3 and 12 hr later, there was a drop in right atrial pressure, pulmonary capillary wedge pressure and cardiac output to 5.6 +/- 0.6 (p less than 0.02), 7.2 +/- 0.8 mm Hg (p less than 0.002) and 7.2 +/- 0.6 L/min (NS) respectively, indicative of the development of relative hypovolemia and suggesting that therapeutic plasma expansion is appropriate at this time. Two-dimensional echocardiography before paracentesis (n = 8) showed a reduction in the right to left atrium area ratio as compared with values in patients with minimal ascites (0.54 +/- 0.04 vs 0.82 +/- 0.02, p less than 0.0001). This technique may help in identifying patients with right atrial compression caused by tense ascites.

Adult↗
PubMed1984

Heat-shock proteins produced by two human melanoma cell lines: absence of correlation with thermosensitivity.

Two human melanoma cell lines, extremely different in their thermal sensitivity, were pulse-labelled with (35S)-methionine after 60 min of exposure at 42 degrees C. For both cell lines, fractionation of the intrinsically labelled proteins by polyacrylamide gel electrophoresis (PAGE) showed increased labelling of a polypeptide band of Mr 72,000, along with a slight reduction of overall protein synthesis. By two-dimensional electrophoresis, the Mr 72,000 band resolved into multiple pattern components of the same size but differing in isoelectric points. The absence of qualitative and quantitative differences between the two melanoma cell lines indicates that the different thermal sensitivities are unrelated to their ability to express the heat-shock proteins.

Cell Line↗
PubMedDate not supplied

Isolation and partial characterization of a 46-kd allergen of Bermuda grass pollen.

Cyn d Bd46K, a 46-kD component of Bermuda grass (Cynodon dactylon) pollen, had been identified as an allergenic constituent. In the present study two-dimensional (2D) gel electrophoresis illustrated the presence of five acidic isoforms in Cyn d Bd46K, and this molecule was purified by monoclonal antibody (MAb) affinity chromatography for further characterization. Using a digoxigenin-labeled lectin-binding assay, the elucidating protein was disclosed to be a glycoprotein with terminal mannose. The involvement of a carbohydrate moiety in the allergenicity and antigenicity of the elucidated molecule was demonstrated with sodium-periodate-treated Cyn d Bd46K, which reduced binding to its specific MAb and human IgE. We were unable to identify the N-terminal amino acid sequences of Cyn d Bd46K, but some internal amino acid sequences were disclosed by microsequencing some fragments cleaved by Achromobacter protease I and fractionated by reversed-phase column chromatography. The amino acid sequences of 4 identified Cyn d Bd46K internal peptide fragments were found to be 25-71% identical with that of cytochrome c oxidase III from corn grass pollen. The present study provided important information for future experiments on the molecular cloning of the elucidated allergen.

Allergens↗
PubMed2000

Association analysis of GABAAbeta2 and gamma2 gene polymorphisms with event-related prefrontal activity in man.

Gamma-aminobutyric acid (GABA)A-receptors play a crucial role in the generation of electroencephalogram (EEG) oscillations and evoked potentials (ERPs). The present association study was designed to test whether EEG and ERPs are modulated by genetic variations of the human GABAA beta2 (GABRB2) and gamma2 (GABRG2) genes on chromosome 5q33. The genotypes of two nucleotide substitution polymorphisms of the GABRB2 and GABRG2 genes were assessed in 95 psychiatrically healthy subjects of German descent. Neurophysiological phenotyping was performed with four factorized EEG/ERP parameters: EEG activation, anterior and posterior EEG synchronization, and event-related activity (N100/ P200-complex). No genotypic association was found for the GABRB2 nucleotide exchange polymorphism with any electrophysiological parameter. A significant association was found between the genotype of the intronic GABRG2 G-->A nucleotide exchange and the event-related N100/P200 (ANOVA: F=3.81; df=2; P=0.026). A comparison of homozygous subjects carrying either the G/G or A/A genotype of the GABRG2 polymorphism consistently revealed an even stronger difference in the effect-size (ANOVA: F=11.13; df=1; P=0.002). Post hoc analysis of this association with current density analysis in three-dimensional neuroanatomic Talairach space-time showed a reduction in the event-related signal power after 120 ms in the right dorsolateral prefrontal cortex. Taking into account the risk of false-positive association findings attributable to multiple testing, our results encourage further replication studies to examine the phenotype-genotype relationship of GABRG2 gene variants and event-related prefrontal activity.

Adult↗
PubMed2005

Responses to nickel in the proteome of the hyperaccumulator plant Alyssum lesbiacum.

A proteomic analysis of the Ni hyperaccumulator plant Alyssum lesbiacum was carried out to identify proteins that may play a role in the exceptional degree of Ni tolerance and accumulation characteristic of this metallophyte. Of the 816 polypeptides detected in root tissue by 2D SDS-PAGE, eleven increased and one decreased in abundance relative to total protein after 6-week-old plants were transferred from a standard nutrient solution containing trace concentrations of Ni to a moderately high Ni treatment (0.3 mM NiSO4) for 48 h. These polypeptides were identified by tandem mass spectrometry and the majority were found to be involved in sulphur metabolism (consistent with a re-allocation of sulphur towards cysteine and glutathione), protection against reactive oxygen species, or heat-shock response. In contrast, very few polypeptides were found to change in abundance in root or shoot tissue after plants were exposed for 28 days to 0.03 mM NiSO4, a concentration representing the optimum for growth of this species but sufficient to lead to hyperaccumulation of Ni in the shoot. Under these conditions, constitutively expressed genes in this highly Ni-tolerant species may be sufficient to allow for effective chelation and sequestration of Ni without the need for additional protein synthesis.

Brassicaceae↗
PubMed1986

Effect of 5,7-dihydroxytryptamine on the concentration of individual proteins in different areas of the rat brain.

Proteins which are apparently regulated in concentration in two different areas of the rat brain by the indole neurotransmitter serotonin were identified using two-dimensional gel electrophoresis combined with computerized scanning densitometry. Reduction in central serotonin levels produced a decrease in the concentration of 3 different proteins (2 in the parietal cortex, 1 in the hippocampus). Two proteins, both in the hippocampus, were elevated in concentration following serotonin depletion. These results demonstrate that there exist in the brain a limited number of proteins whose concentration is influenced by serotonin.

5,7-Dihydroxytryptamine↗
PubMed1985

Mouse egg extracellular coat is a matrix of interconnected filaments possessing a structural repeat.

As the result of a combined biochemical and electron microscopic investigation, hitherto unrecognized structural features of the mouse egg extracellular coat, or zona pellucida, have been revealed. Specimens were prepared for electron microscopy by spraying individually isolated zonae pellucidae onto a substrate and were observed by both rotary shadowing and negative staining techniques. Results of these experiments suggest that the three zona pellucida glycoproteins, ZP1 (200,000 Mr), ZP2 (120,000 Mr) and ZP3 (83,000 Mr), are organized into long filaments. Negatively stained zona pellucida filaments resemble "beads-on-a-string", with each bead (9.5 nm in diameter) located every 17 nm or so (center-to-center distance) along the axis of the filament. The filaments, in turn, appear to be interconnected by one of the three zona pellucida glycoproteins, ZP1, giving rise to a three-dimensional matrix. Proteolysis of ZP1 by chymotrypsin or reduction of intermolecular disulfides of ZP1 by dithiothreitol results in both solubilization of zonae pellucidae and disruption of interconnections between individual zona pellucida filaments. These observations suggest that the zona pellucida, which plays important roles both during and after fertilization of mammalian eggs, is a highly organized extracellular coat in which glycoproteins are assembled into filaments possessing a recognizable structural repeat.

Animals↗
PubMed2005

Complications encountered while using thin-wire-hybrid-external fixation modular frames for fracture fixation. A retrospective clinical analysis and possible support for "Damage Control Orthopaedic Surgery".

One hundred ninety eight adult patients who had sustained long bone fractures were treated by external fixation from admission to bone healing and consolidation. Of these, 135 had sustained high-energy injuries, 39 of them had suffered multi-system injuries. Superficial pin track infection was the most common complication, occurring predominantly in pins located in the femur, upper tibia and upper humerus. There were no cases of deep infection or osteomyelitis. One patient with a femoral shaft fracture developed a DVT although he was on preventive low molecular weight heparin, i.e. sc Clexane 40 mg daily. There were no cases of PE or ARDS. External fixation systems are a minimal invasive surgical modality, which allow three-dimensional fracture fixation after closed or minimal open reduction. They require a good command of surgical anatomy, but provide an optimal preservation of the fracture's soft tissue envelope, the critical biological factor for new bone formation and fracture healing. Recent publications have suggested that in the critically ill patient, minimally invasive fracture fixation surgery may prevent the perpetuation of a reactive, life threatening inflammatory reaction (the "second hit") which may induce the development of multiple organ dysfunction (MODS).

Adult↗
PubMed2004

Copper-induced oxidative stress in Saccharomyces cerevisiae targets enzymes of the glycolytic pathway.

Increased cellular levels of reactive oxygen species are known to arise during exposure of organisms to elevated metal concentrations, but the consequences for cells in the context of metal toxicity are poorly characterized. Using two-dimensional gel electrophoresis, combined with immunodetection of protein carbonyls, we report here that exposure of the yeast Saccharomyces cerevisiae to copper causes a marked increase in cellular protein carbonyl levels, indicative of oxidative protein damage. The response was time dependent, with total-protein oxidation peaking approximately 15 min after the onset of copper treatment. Moreover, this oxidative damage was not evenly distributed among the expressed proteins of the cell. Rather, in a similar manner to peroxide-induced oxidative stress, copper-dependent protein carbonylation appeared to target glycolytic pathway and related enzymes, as well as heat shock proteins. Oxidative targeting of these and other enzymes was isoform-specific and, in most cases, was also associated with a decline in the proteins' relative abundance. Our results are consistent with a model in which copper-induced oxidative stress disables the flow of carbon through the preferred glycolytic pathway, and promotes the production of glucose-equivalents within the pentose phosphate pathway. Such re-routing of the metabolic flux may serve as a rapid-response mechanism to help cells counter the damaging effects of copper-induced oxidative stress.

Carbon↗
PubMed1995

2D and 3D CT reconstructions of the facial skeleton: an unnecessary option or a diagnostic pearl?

The introduction of spiral computed tomography (CT) has been a major advance in CT scanning, particularly considering the reduction in acquisition time and improvements in 2-dimensional (2D) and 3D reconstructions. 314 out of 1262 CT examinations of the midface and jaws executed from September 1993 to September 1994 were performed in the spiral mode. Our experience is critically reviewed and a guideline for the use of spiral CT scanning of the midface and jaws for various diagnostic purposes is established: Complex midface fractures require axial spiral CT scanning with secondary coronal reconstructions Because of the long processing time 3D reconstructions are reserved for planning surgical repair of craniofacial malformations. Dental CT scans with calculation of panoramic images provide important information prior to dental implant surgery and repair of alveolar clefts.

Computer Simulation↗
PubMed2002

2-Deoxy-2-[18F]fluoro-D-glucose positron emission tomography in target volume definition for radiotherapy of patients with non-small-cell lung cancer.

PURPOSE: To discuss the potential contribution of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (FDG-PET) in radiotherapy planning for non-small-cell lung cancer (NSCLC) considering new concepts on target volume definition. PROCEDURES: Recent investigations on the topic are reviewed with regard to current concepts of target volume definition for NSCLC. RESULTS: As intrathoracic recurrence is the leading cause of death after primary radiotherapy of NSCLC, there is a need for improving local control by escalating treatment intensity to gross disease. The value of elective nodal irradiation (ENI), resembling prophylactic irradiation of macroscopically unaffected parts of the mediastinum, is being considered. CONCLUSION: As FDG-PET has been shown to enhance the diagnostic accuracy of computed tomography (CT), and to have a potentially high impact on the identification of malignant tissue, it should be implicated in prospective clinical trials on dose escalation and three-dimensional conformal radiotherapy, especially in those including a reduction of target volumes.

Journal Article↗
PubMed1989

Metabolic behavior of cell surface biotinylated proteins.

The turnover of proteins on the surface of cultured mammalian cells was measured by a new approach. Reactive free amino or sulfhydryl groups on surface-accessible proteins were derivatized with biotinyl reagents and the proteins solubilized from culture dishes with detergent. Solubilized, biotinylated proteins were then adsorbed onto streptavidin-agarose, released with sodium dodecyl sulfate and mercaptoethanol, and separated on polyacrylamide gels. Biotin-epsilon-aminocaproic acid N-hydroxysuccinimide ester (BNHS) or N-biotinoyl-N'-(maleimidohexanoyl)hydrazine (BM) were the derivatizing agents. Only 10-12 bands were adsorbed onto streptavidin-agarose from undervatized cells or from derivatized cells treated with free avidin at 4 degrees C. Two-dimensional isoelectric focusing-sodium dodecyl sulfate gel electrophoresis resolved greater than 100 BNHS-derivatized proteins and greater than 40 BM-derivatized proteins. There appeared to be little overlap between the two groups of derivatized proteins. Short-term pulse-chase studies showed an accumulation of label into both groups of biotinylated proteins up until 1-2 h of chase and a rapid decrease over the next 1-5 h. Delayed appearance of labeled protein at the cell surface was attributed to transit time from site of synthesis. The unexpected and unexplained rapid disappearance of pulse-labeled proteins from the cell surface was invariant for all two-dimensionally resolved proteins and was sensitive to temperature reduction to 18 degrees C. Long-term pulse-chase experiments beginning 4-8 h after the initiation of chase showed the disappearance of derivatized proteins to be a simple first-order process having a half-life of 115 h in the case of BNHS-derivatized proteins and 30 h in the case of BM-derivatized proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Aminocaproates↗
PubMed2004

Langmuir-Blodgett films of amphiphilic bis(tetrathiafulvalene) macrocycles with four alkyl chains.

Amphiphilic bis(tetrathiafulvalene) [bis(TTF)] macrocycles with four alkyl chains were fabricated as novel electrically active Langmuir-Blodgett (LB) films. Two TTF units were linked via [24]crown-8, [21]crown-7, and [18]crown-6 macrocycles, forming charge-transfer (CT) salts with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinodimethane (F4-TCNQ) at the air-water interface and on solid substrates. The CT salt of the amphiphilic bis(TTF)-macrocycle having a [24]crown-8 ring system formed a uniform surface morphology on mica. Using single-crystal X-ray structural analysis, the layer structure between the hydrophobic chains and the one-dimensional pi-pi stack of the CT salt was confirmed. Our results show that the bis(TTF)-macrocycle was folded at the flexible [24]crown-8 moiety, forming intramolecular pi-pi dimer structures and one-dimensional intermolecular pi-pi stacks with F4-TCNQ dimers. The open-shell electronic structure of the LB films was determined by electronic spectra, electrical conductivity, and electron spin resonance analyses. Asymmetry was introduced into the bis(TTF)-macrocycle by changing the ring size from [24]crown-8 to [21]crown-7. The surface morphology of the CT salts with F4-TCNQ was established as two-dimensional round-shape domains on mica. Further reduction of the macrocyclic ring from [21]crown-7 to [18]crown-6 resulted in a CT salt of the bis(TTF)-macrocycle with F4-TCNQ with a leaf-shape domain morphology and a typical dimension of approximately 1 microm2 on mica. In general, decreasing the macrocyclic ring size from [24]crown-8 to [21]crown-7 or [18]crown-6 affected the inter- and intramolecular interactions and the surface morphologies of LB films.

Journal Article↗
PubMed2002

The transcription termination factor Rho is required for oxidative stress survival in Caulobacter crescentus.

A transposon Tn5 mutagenesis library was generated from Caulobacter crescentus strain NA1000, and clones with deficiency in survival in a high concentration of NaCl were selected. One of these clones, 37G10, has the Tn5 integrated within the coding region of the transcription termination factor Rho. Analysis of this mutant phenotype showed that the cells are motile and present a normal cell cycle, but have a longer generation time. This strain is sensitive to acidic pH, to the presence of different salts and to heat shock, but it responds well to UV light and alkaline pH. The most striking phenotype of the rho mutant is that it is extremely sensitive to oxidative stress, in both exponential and stationary phases. Experiments using a transcriptional fusion of the rho promoter region to the lacZ gene showed that rho gene expression varies during the cell cycle, showing very low expression levels at the swarmer cell stage and presenting maximum levels in early predivisional cells. Transcription of the rho gene is increased in the rho mutant strain, which is indicative of an autoregulatory circuit, and there is a small variation in the cell cycle pattern of expression. Several peptides have their synthesis altered in the mutant strain, as analysed by two-dimensional gel electrophoresis, most of which show a reduction in expression. These results indicate that the Rho factor is essential for an efficient response to certain stresses in Caulobacter.

Amino Acid Sequence↗
PubMed2002

Degeneration of pontine mossy fibres during cerebellar development in weaver mutant mice.

In weaver mutant mice, substitution of an amino acid residue in the pore region of GIRK2, a subtype of the G-protein-coupled inwardly rectifying K+ channel, changes the properties of the homomeric channel to produce a lethal depolarized state in cerebellar granule cells and dopaminergic neurons in substantia nigra. Degeneration of these types of neurons causes strong ataxia and Parkinsonian phenomena in the mutant mice, respectively. On the other hand, the mutant gene is also expressed in various other brain regions, in which the mutant may have effects on neuronal survival. Among these regions, we focused on the pontine nuclei, the origin of the pontocerebellar mossy fibres, projecting mainly into the central region of the cerebellar cortex. The results of histological analysis showed that by P9 the number of neurons in the nuclei was reduced in the mutant to about one half and by P18 to one third of those in the wild type, whereas until P7 the number were about the same in wild-type and weaver mutant mice. Three-dimensional reconstruction of the nuclei showed a marked reduction in volume and shape of the mutant nuclei, correlating well with the decrease in neuronal number. In addition, DiI (a lipophilic tracer dye) tracing experiments revealed retraction of pontocerebellar mossy fibres from the cerebellar cortex after P5. From these results, we conclude that projecting neurons in the pontine nuclei, as well as cerebellar granule cells and dopaminergic neurons in substantia nigra, strongly degenerate in weaver mutant mice, resulting in elimination of pontocerebellar mossy fibres during cerebellar development.

Animals↗
PubMedDate not supplied

[Etiology and pathogenesis of epiphyseal necrosis in childhood as exemplified with the hip].

In many cases the etiology of juvenile necrosis of the femoral head has not been unequivocally explained. Essentially, however, it is due to reduced arterial blood flow, although venous congestion also has to be considered. Epiphyseal necrosis is frequently a result of known underlying diseases. These include, for example, both specific and nonspecific forms of coxitis and rheumatic coxitis, hormonal dysfunctions, metabolic disorders such as mucopolysaccharidosis, blood diseases (e.g. hemophilia, sickle cell anemia), leukosis, and tumors and necrosis following cortisone and cytostatic therapy. The following four factors may directly or indirectly cause arterial vascular damage and thus necrosis: 1) primarily exogenous and 2) primarily endogenous factors, 3) genetic, and 4) skeletal maturation factors. These etiological factors are described in detail and discussed. Epiphyseal deformation occurs in a strict sequence of five phases, which are described. It should be emphasized that while necrotic bone tissue is being gradually resorbed, deposits of new bone matrix are already accumulating on dead trabecula and will subsequently form new bone fibre. In other word, a gradual substitution takes place. Two important clinical facts derive from this. First, epiphyseal crash is not due to the load of the body's weight. Since active resorption takes place, there is no justification for weight-relieving therapy in the basic therapeutic concept for Perthes' disease. Second, in light of our studies, surgical containment therapy appears to be the most suitable form of treatment if performed at the right time, i.e. in the golden period of remodelling, depending on the patient's age, the extent of necrosis and the degree of dislocation. Where stringent criteria are fulfilled we perform a three-dimensional intertrochanteric osteotomy, i.e. an extension-derotation reduction osteotomy.

Child↗