23 results on '"E Petrik"'
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2. Proximal Submarine Fan Reservoir Architecture and Development in the Upper Jurassic Brae Formation of the Brae Fields, South Viking Graben, U.K. North Sea
- Author
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Colin C. Turner, Falene E. Petrik, E. Rodger Connell, and Rodrigo E. Bastidas
- Subjects
Turbidity current ,Rift ,020209 energy ,02 engineering and technology ,010502 geochemistry & geophysics ,Fault scarp ,01 natural sciences ,Sedimentary depositional environment ,Graben ,Paleontology ,Kimmeridge Clay ,Clastic rock ,Facies ,0202 electrical engineering, electronic engineering, information engineering ,Geology ,0105 earth and related environmental sciences - Abstract
Upper Jurassic proximal submarine fan deposits form the reservoirs of three large oil and gas condensate fields in Block 16/7a at the western margin of the U.K. South Viking Graben. High-relief (up to 1670 ft [∼510 m]) hydrocarbon columns are trapped by a combination of abutment against the graben margin fault system to the west, basinward slope away from the graben margin to the east, and lateral stratigraphic trapping against interfan fine-grained sediments. Gravel and sand were supplied to the fans by noncohesive debris flows and high-density turbidity currents down an eroded fault scarp from the platform area of the Fladen Ground Spur to the west. The South Brae and North Brae fields have pronounced conglomeratic channel systems in the upper part of the Brae Formation, which pass down-dip into thick, laterally extensive (up to 25 km [16 mi]) basin-floor sandstone fans that host three other large fields, Miller, Kingfisher, and East Brae. The Central Brae field is contained within a more cone-shaped fan, with thick conglomeratic deposits in the most proximal area that grade downdip into a thick sandstone package of relatively limited basinward extent (approximately 7 km [4 mi] downslope). The fan systems of the Brae Formation are contained within the Kimmeridge Clay Formation, which is a world-class source rock and also provides the top seal for the fields. Numerous exploration, appraisal, and development wells, supported by seismic imaging and reservoir pressure and production data, allow the architecture of the proximal fan systems to be established. The best developed channel systems at South Brae, which occur in the upper part of the reservoir, are approximately 1 km (0.6 mi) wide and are separated by thick units of interchannel mudstones and thin sandstones. These channels widen and become unconfined downdip where they merge into the basin-floor fan systems. Channel-fill sequences, which can total around 300 ft (91 m) in thickness, typically comprise a unit of very thick-bedded conglomerates with minor interbedded sandstones, which is overlain by a unit of thick-bedded sandstones up to 100 ft (30 m) thick. In individual South Brae reservoir layers, several channels that radiate from a single sediment source area can be found. In contrast, a single prominent channel system exists at the North Brae field, where the channel facies are similar to those at South Brae, but the total channel thickness reaches 800 ft (244 m). On the southern flank of the North Brae field, thick sandstone lobes occur that are connected to the central channel, and on the north side of the field, separate channel systems exist, which contain hydrocarbons that are not connected to the main field area. At Central Brae, laterally extensive, poorly confined channel systems were probably the depositional avenues in the upper part of the reservoir, but the bulk of the reservoir comprises a stacked sequence of downdip elongated tongues of conglomerates and thinner sandstones, which pass downslope into thick-bedded sandstones. Fan systems, which evolved through time, began to develop in the Brae area in the mid to late Oxfordian (from around 160 Ma), during the initial phase of intense rifting, but the increased organization in sediment dispersal patterns and the extension of the fans into the basin center occurred from the late Kimmeridgian (about 152 Ma) as rift extension ceased. Coarse clastic deposition during the later phases of the fans was periodically interrupted by deposition of mudstones, probably as a result of episodes of high relative sea level temporarily flooding the source areas. Central Brae was the first fan to be abandoned, followed by the South Brae system, and finally the North Brae system in the earliest late Volgian (around 144 Ma), when the Fladen Ground Spur was finally transgressed. Fan abandonment appears to have been relatively rapid as good quality turbidite sandstones occur very close to the top of the final depositional systems in both the basin-floor and proximal locations.
- Published
- 2018
- Full Text
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3. Hammertoe correction using an absorbable pin
- Author
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Kathleen E. Suthers, Mark E. Petrik, Marilyn W. Smith, and Kurt Voos
- Subjects
Orthodontics ,Alternative methods ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Arthrodesis ,Hammertoes ,Radial head ,Poly-p-dioxanone ,Arthroplasty ,Surgery ,Fixation (surgical) ,medicine ,Orthopedics and Sports Medicine ,business - Abstract
Bioabsorbable implants have found an increasing number of uses, including fractures of the malleoli, radial head, and distal radius, among others. We have begun to use bioabsorbable pins for the purpose of hammertoe correction. K-wires have been the traditional method of fixation for arthroplasty/arthrodesis in the correction of hammertoes. We describe an alternative method using poly-p-dioxanone 2-mm absorbable pins. This method may prove to reduce infection by avoiding exposed pins and gives patients an earlier return to normal footwear.
- Published
- 1996
- Full Text
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4. Powerlessness and the Need to Control
- Author
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Rebecca E. Petrik Olson, Norman D. Petrik, and Leah S. Subotnik
- Subjects
medicine.medical_treatment ,media_common.quotation_subject ,education ,05 social sciences ,Shame ,050109 social psychology ,humanities ,Group psychotherapy ,Dilemma ,Clinical Psychology ,medicine ,Domestic violence ,0501 psychology and cognitive sciences ,Psychology ,Applied Psychology ,After treatment ,050104 developmental & child psychology ,media_common ,Clinical psychology - Abstract
Male abusers who attended a 6-month outpatient Domestic Abuse treatment program and their female partners completed measures of powerlessness and tolerance for being controlled, both before and after the men completed treatment. Before treatment: (a) both men and women felt powerless; (b) men had a very low tolerance for being controlled, and the women tolerated moderate amounts of control; (c) men and women accurately perceived their partners' tolerance for being controlled; and (d) the women perceived the men to be more powerful than the men perceived themselves. Contrary to the study's hypothesis, treatment failed to decrease abusers' powerlessness or to increase their tolerance for being controlled. The most noteworthy indication of change as a result of treatment was a somewhat greater similarity between men's and women's perceptions of male powerlessness after treatment. The authors speculated that the group therapy treatment program emphasizing shame reduction helped men to acknowledge their powerlessness more openly and consequently move toward decreasing control of their partners.
- Published
- 1994
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5. 413 Estimation of myocardial perfusion relative to the presence of myocardial viability in patients with left ventricular dysfunction during 3 months therapy with metoprolol or carvedilol
- Author
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S. Shalaev, E. Petrik, O. Reitblat, E. Metlitskaya, and D. Teffenberg
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medicine.medical_specialty ,business.industry ,Internal medicine ,medicine ,Cardiology ,In patient ,Cardiology and Cardiovascular Medicine ,business ,Perfusion ,Carvedilol ,Metoprolol ,medicine.drug - Published
- 2005
- Full Text
- View/download PDF
6. Reviews
- Author
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David Herlihy, J. A. Sharpe, Roderick Floud, Peter Bakewell, Jon S. Cohen, J. M. Roberts, Paula E. Petrik, Pierre Ayçoberry, Joan Wallach Scott, Kenneth Lunn, S. A. Smith, Barrie M. Ratcliffe, and W. R. Garside
- Subjects
History - Published
- 1981
- Full Text
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7. Treatment of castration-induced osteoporosis by a capacitively coupled electrical signal in rat vertebrae
- Author
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David R. Steinberg, C P Luessenhop, Frederick S. Kaplan, M E Petrik, Carl T. Brighton, and Solomon R. Pollack
- Subjects
Apparent density ,Centimeter ,Square Centimeter ,business.industry ,Osteoporosis ,General Medicine ,Anatomy ,Lumbar vertebrae ,medicine.disease ,Signal ,chemistry.chemical_compound ,Castration ,Lumbar ,medicine.anatomical_structure ,chemistry ,medicine ,Orthopedics and Sports Medicine ,Surgery ,business - Abstract
Castrated male Sprague Dawley rats were subjected to various capacitively coupled electrical fields for six and eight weeks at two and 4.5 months after castration, respectively, with pairs of electrodes that were located paraspinally on the surface of the skin dorsally at the eleventh thoracic and fourth lumbar levels. When the animals were killed, dry and ash weights per unit of volume (apparent density), elastic modulus, ultimate stress, work to failure, trabecular area fraction, and mean trabecular width were determined for selected vertebrae. The results indicated that a sixty-kilohertz, 100-microampere signal (a calculated current density of five microamperes root-mean-square per square centimeter and a field of twelve millivolts root-mean-square per centimeter) significantly reversed the castration-induced osteoporosis in the lumbar vertebrae and restored bone mass per unit of volume in rats that had been stimulated for eight weeks after castration.
- Published
- 1989
- Full Text
- View/download PDF
8. EVD-gestützte Operationsdatei: Methodik und Anwendungsmöglichkeiten
- Author
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E. Petrik, R. Schedl, and A. Chrysopoulos
- Published
- 1988
- Full Text
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9. Analyse unbefriedigender Ergebnisse nach konservativer Therapie von Unterarmschaftfrakturen
- Author
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G. Ittner, E. Petrik, and M. Strickner
- Published
- 1989
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10. Methodik der computergestützten Auswertung von konservativ behandelten Unterarmbrüchen
- Author
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A. Chrysopoulos, W. Dorda, M. Strickner, Ch. Reichetzeder, and E. Petrik
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- 1989
- Full Text
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11. Computergraphische Analyse von Unterarmschaftfrakturen im Wachstumsalter
- Author
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E. Petrik, A. Chrysopoulos, M. Strickner, and G. Ittner
- Subjects
business.industry ,Medicine ,business - Published
- 1989
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12. Funktionelle Endergebnisse nach operativ und konservativ behandelten Monteggia-Frakturen
- Author
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E. Petrik, Ch. Rizzi, and G. Ittner
- Subjects
business.industry ,Medicine ,business - Published
- 1989
- Full Text
- View/download PDF
13. Treatment of castration-induced osteoporosis by a capacitively coupled electrical signal in rat vertebrae
- Author
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C T, Brighton, C P, Luessenhop, S R, Pollack, D R, Steinberg, M E, Petrik, and F S, Kaplan
- Subjects
Male ,Lumbar Vertebrae ,Time Factors ,Animals ,Osteoporosis ,Electric Stimulation Therapy ,Rats, Inbred Strains ,Organ Size ,Orchiectomy ,Thoracic Vertebrae ,Rats - Abstract
Castrated male Sprague Dawley rats were subjected to various capacitively coupled electrical fields for six and eight weeks at two and 4.5 months after castration, respectively, with pairs of electrodes that were located paraspinally on the surface of the skin dorsally at the eleventh thoracic and fourth lumbar levels. When the animals were killed, dry and ash weights per unit of volume (apparent density), elastic modulus, ultimate stress, work to failure, trabecular area fraction, and mean trabecular width were determined for selected vertebrae. The results indicated that a sixty-kilohertz, 100-microampere signal (a calculated current density of five microamperes root-mean-square per square centimeter and a field of twelve millivolts root-mean-square per centimeter) significantly reversed the castration-induced osteoporosis in the lumbar vertebrae and restored bone mass per unit of volume in rats that had been stimulated for eight weeks after castration.
- Published
- 1989
14. Predisposing factors of atelectasis following pulmonary lobectomy
- Author
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Robert Lischke, Tomas Harustiak, Pavel Pafko, Jan Schutzner, Stolz A, and E Petrik
- Subjects
Male ,Pulmonary Atelectasis ,medicine.medical_specialty ,Lung Neoplasms ,Atelectasis ,Adenocarcinoma ,Pulmonary Disease, Chronic Obstructive ,Postoperative Complications ,Bronchoscopy ,Pulmonary lobectomy ,Postoperative atelectasis ,medicine ,Humans ,Carcinoma, Small Cell ,Risk factor ,Pneumonectomy ,Aged ,Retrospective Studies ,Lung ,medicine.diagnostic_test ,business.industry ,Respiratory disease ,Retrospective cohort study ,General Medicine ,Length of Stay ,Middle Aged ,medicine.disease ,Surgery ,medicine.anatomical_structure ,Carcinoma, Squamous Cell ,Female ,business - Abstract
The aims of our study were to investigate postoperative atelectasis complicating pulmonary lobectomy, identify risk factors and evaluate its relationship to other postoperative complications.From January 2004 to April 2007, 412 patients underwent pulmonary lobectomy. We performed a retrospective analysis of our prospective database. Post-lobectomy atelectasis (PLA) was defined as an ipsilateral opacification of the remaining lobe with an ipsilateral shift of the mediastinum on the chest radiography, requiring bronchoscopy.The incidence of PLA was 6.6%, comprising 29% of all postoperative pulmonary complications seen. There was no statistically significant difference in patient age, gender, ASA score, cardiovascular co-morbidity or operation time for the PLA group versus the group without this complication. Current smokers were at a higher risk for PLA, but this incidence did not reach statistical significance. Chronic obstructive pulmonary disease (COPD) was the only preoperative variable increasing the risk of PLA (p0.05). Patients undergoing a right upper lobectomy, either on its own or in combination with a right middle lobe resection, had a significantly higher incidence of PLA when compared with all other types of resection (p0.05).Patients with COPD and those undergoing right upper lobe resection have an increased risk of PLA. In this group of patients we should use pre-operative (cessation of cigarette smoking, treatment of airflow obstruction in patients with COPD), intra-operative (duration of operation) and postoperative (intensive physiotherapy and effective postoperative pain control) measures to decrease the risk of PLA. Although often solitary, PLA is associated with a longer hospital stay.
15. Posttraumatic Gluteal Compartment Syndrome
- Author
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Jeffery L. Stambough, Richard H. Rothman, and Mark E. Petrik
- Subjects
medicine.medical_specialty ,business.industry ,Sciatic nerve palsy ,Radiography ,General Medicine ,Surgery ,body regions ,Gluteal compartment ,nervous system ,Edema ,medicine ,Gluteal region ,Severe pain ,Orthopedics and Sports Medicine ,Sciatic nerve ,Differential diagnosis ,medicine.symptom ,business - Abstract
Posttraumatic sciatic nerve palsy associated with severe pain, swelling in the gluteal region, elevated tissue pressures, and diffuse edema of the gluteal musculature documented by computed tomography (CT) occurred in a 22-year-old man. Diffuse muscle swelling was observed intraoperatively, and sciatic nerve function returned within days following surgical decompression. This case represents an acute gluteal compartment syndrome, and this entity should be included in the differential diagnosis of posttraumatic sciatic nerve palsy.
- Published
- 1988
- Full Text
- View/download PDF
16. Search for the electric dipole moment of the electron with thorium monoxide.
- Author
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A C Vutha, W C Campbell, Y V Gurevich, N R Hutzler, M Parsons, D Patterson, E Petrik, B Spaun, J M Doyle, G Gabrielse, and D DeMille
- Subjects
DIPOLE moments ,ELECTRONS ,THORIUM ,OXIDES ,PARTICLES (Nuclear physics) ,DIELECTRICS - Abstract
Equation (11) in the published version of this article was missing a couple of terms. The corrected equation can be found in the pdf file. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
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17. Risk Mitigation Strategies to Prevent Transmission of COVID-19 in the Military Classroom Setting: A Case of a Symptomatic SARS-CoV2 Positive Student without Apparent Spread to Classmates.
- Author
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Petrik E and Mease L
- Subjects
- Adult, COVID-19 diagnosis, COVID-19 transmission, Hand Disinfection, Humans, Male, Masks, Schools, Nursing organization & administration, COVID-19 prevention & control, Communicable Disease Control organization & administration, Military Medicine education, Military Personnel
- Abstract
Since the onset of the COVID-19 pandemic in late 2019, the world community has responded with ever-evolving measures to reduce the spread of SARS CoV-2, the virus that causes COVID-19 (Coronavirus Disease 2019)1. One particular area of interest is understanding the risk of the in-person classroom setting and if any mitigation efforts are effective in preventing the spread of disease in that setting. In this paper, we present a case study of a US Army Advanced Individual Training (AIT) course/classroom wherein a student was diagnosed with COVID-19, and there was no apparent spread to others in his classroom. We discuss the mitigation efforts put in place that appear to be, in this case, effective in preventive onward spread of the virus. These are social distancing, face coverings/masks, and hygiene practices including hand washing and sanitation of surfaces.
- Published
- 2021
18. Characteristics and outcomes of gastroduodenal ulcer bleeding: a single-centre experience in Lithuania.
- Author
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Petrik P, Brašiškienė S, and Petrik E
- Abstract
Introduction: Despite the optimal use of combined endoscopic haemostasis and pharmacologic control of acid secretion in the stomach, mortality in patients with peptic ulcer bleeding (PUB) has remained constant. Recent data has shown that the majority of patients with PUB die of non-bleeding-related causes., Aim: To provide an overview of our experience of PUB management, with emphasis on the effect of age, gender, comorbidities, and drug use on the characteristics and outcomes of gastroduodenal ulcer bleeding., Material and Methods: We retrospectively reviewed the medical records of all patients admitted with the primary diagnosis of acute, chronic or unspecified gastric and/or duodenal ulcer with haemorrhage during 2008-2012., Results: Two hundred and nineteen patients were identified. 46.6% of patients were ≥ 65 years old (elderly) and 53.4% were < 65 years old (young). The young patients were more likely to have duodenal ulcers and liver failure at admission. Previous use of medications was more regularly observed in gastric ulcer patients than in duodenal ulcer patients. Rebleeding occurred in 43 (19.6%) patients and death in 5 (2.3%) patients. Increased risk of mortality in our patients was associated with age ≥ 65 years (RR = 2.21; 95% CI: 1.90-2.56; p = 0.021)., Conclusions: Management of peptic ulcer bleeding should aim at reducing the risk of multiorgan failure and cardiopulmonary death instead of focusing merely on successful haemostasis.
- Published
- 2017
- Full Text
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19. Surgical management of gastrointestinal stromal tumors: a single center experience.
- Author
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Poškus E, Petrik P, Petrik E, Lipnickas V, Stanaitis J, and Strupas K
- Abstract
Introduction: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. Although the therapy targeted at inhibiting tyrosine kinases has shown dramatic results in metastatic and inoperable GISTs, the mainstay of treatment in primary localized forms remains surgical resection., Aim: To provide an overview of our experience of GIST diagnosis and management, with emphasis on comparison of minimally invasive and open surgical resection for primary GISTs., Material and Methods: We retrospectively reviewed the medical records of all patients who underwent surgical removal of GISTs from 2008 to 2012. Patient demographics, clinical data, surgery, complications, histopathological data and clinical course were analyzed., Results: Forty-four patients were identified. Average age at diagnosis was 63 years. Minimally invasive (MIS) and open surgery (OS) were each attempted in 22 (50.0%) patients. Laparoscopic removal was performed in 20, laparoendoscopic in 1, and laparoscopy-assisted endoscopic removal in 1. Conversion to an open procedure was performed in 4 (18.2%). We found significant differences in postoperative length of stay (8.5 days vs. 10.1 days, p < 0.001) and tumor size (2.93 cm vs. 5.78 cm, p = 0.018) between MIS and OS groups, respectively., Conclusions: Laparoscopic removal is safe and effective for GISTs not exceeding 6 cm. Gastroesophageal junction and cardia GISTs require careful preoperative evaluation and planning to remove safely. We recommend avoiding laparoscopic removal of these tumors due to the high rate of conversion (100.0%) to an open procedure. Laparoendoscopic surgical approach is an appropriate technique for removal of small-sized intraluminal benign GISTs not involving the muscularis propria layer.
- Published
- 2014
- Full Text
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20. A cryogenic beam of refractory, chemically reactive molecules with expansion cooling.
- Author
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Hutzler NR, Parsons MF, Gurevich YV, Hess PW, Petrik E, Spaun B, Vutha AC, DeMille D, Gabrielse G, and Doyle JM
- Abstract
Cryogenically cooled buffer gas beam sources of the molecule thorium monoxide (ThO) are optimized and characterized. Both helium and neon buffer gas sources are shown to produce ThO beams with high flux, low divergence, low forward velocity, and cold internal temperature for a variety of stagnation densities and nozzle diameters. The beam operates with a buffer gas stagnation density of ∼10(15)-10(16) cm(-3) (Reynolds number ∼1-100), resulting in expansion cooling of the internal temperature of the ThO to as low as 2 K. For the neon (helium) based source, this represents cooling by a factor of about 10 (2) from the initial nozzle temperature of about 20 K (4 K). These sources deliver ∼10(11) ThO molecules in a single quantum state within a 1-3 ms long pulse at 10 Hz repetition rate. Under conditions optimized for a future precision spectroscopy application [A. C. Vutha et al., J. Phys. B: At., Mol. Opt. Phys., 2010, 43, 074007], the neon-based beam has the following characteristics: forward velocity of 170 m s(-1), internal temperature of 3.4 K, and brightness of 3 × 10(11) ground state molecules per steradian per pulse. Compared to typical supersonic sources, the relatively low stagnation density of this source and the fact that the cooling mechanism relies only on collisions with an inert buffer gas make it widely applicable to many atomic and molecular species, including those which are chemically reactive, such as ThO.
- Published
- 2011
- Full Text
- View/download PDF
21. Identification of a mechanical rheostat in the hydrophobic core of protein L.
- Author
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Sadler DP, Petrik E, Taniguchi Y, Pullen JR, Kawakami M, Radford SE, and Brockwell DJ
- Subjects
- Amino Acid Substitution, Bacterial Proteins genetics, Microscopy, Atomic Force methods, Models, Molecular, Mutant Proteins chemistry, Mutant Proteins genetics, Protein Stability, Sequence Deletion, Bacterial Proteins chemistry
- Abstract
The ability of proteins and their complexes to withstand or respond to mechanical stimuli is vital for cells to maintain their structural organisation, to relay external signals and to facilitate unfolding and remodelling. Force spectroscopy using the atomic force microscope allows the behaviour of single protein molecules under an applied extension to be investigated and their mechanical strength to be quantified. protein L, a simple model protein, displays moderate mechanical strength and is thought to unfold by the shearing of two mechanical sub-domains. Here, we investigate the importance of side-chain packing for the mechanical strength of protein L by measuring the mechanical strength of a series of protein L variants containing single conservative hydrophobic volume deletion mutants. Of the five thermodynamically destabilized variants characterised, only one residue (I60 V) close to the interface between two mechanical sub-domains was found to differ in mechanical properties to wild type (Delta F(I60 V-WT)=-36 pN at 447 nm s(-1), Delta x(uI60V-WT)=0.2 nm). Phi-value analysis of the unfolding data revealed a highly native transition state. To test whether the number of hydrophobic contacts across the mechanical interface does affect the mechanical strength of protein L, we measured the mechanical properties of two further variants. protein L L10F, which increases core packing but does not enhance interfacial contacts, increased mechanical strength by 13+/-11 pN at 447 nm s(-1). By contrast, protein L I60F, which increases both core and cross-interface contacts, increased mechanical strength by 72+/-13 pN at 447 nm s(-1). These data suggest a method by which nature can evolve a varied mechanical response from a limited number of topologies and demonstrate a generic but facile method by which the mechanical strength of proteins can be rationally modified.
- Published
- 2009
- Full Text
- View/download PDF
22. Mechanism of lysophosphatidic acid-induced amyloid fibril formation of beta(2)-microglobulin in vitro under physiological conditions.
- Author
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Pál-Gábor H, Gombos L, Micsonai A, Kovács E, Petrik E, Kovács J, Gráf L, Fidy J, Naiki H, Goto Y, Liliom K, and Kardos J
- Subjects
- Amyloid metabolism, Amyloid ultrastructure, Binding Sites, Circular Dichroism, Hydrogen-Ion Concentration, Models, Molecular, Osmolar Concentration, Protein Folding, Protein Structure, Secondary, Temperature, beta 2-Microglobulin metabolism, beta 2-Microglobulin ultrastructure, Amyloid chemistry, Lysophospholipids pharmacology, beta 2-Microglobulin chemistry
- Abstract
Beta(2)-microglobulin- (beta2m-) based fibril deposition is the key symptom in dialysis-related amyloidosis. beta2m readily forms amyloid fibrils in vitro at pH 2.5. However, it is not well understood which factors promote this process in vivo, because beta2m cannot polymerize at neutral pH without additives even at elevated concentration. Here we show that lysophosphatidic acid (LPA), an in vivo occurring lysophospholipid mediator, promotes amyloid formation under physiological conditions through a complex mechanism. In the presence of LPA, at and above its critical micelle concentration, native beta2m became sensitive to limited proteolytic digestion, indicating increased conformational flexibility. Isothermal titration calorimetry indicates that beta2m exhibits high affinity for LPA. Fluorescence and CD spectroscopy, as well as calorimetry, showed that LPA destabilizes the structure of monomeric beta2m inducing a partially unfolded form. This intermediate is capable of fibril extension in a nucleation-dependent manner. Our findings also indicate that the molecular organization of fibrils formed under physiological conditions differs from that of fibrils formed at pH 2.5. Fibrils grown in the presence of LPA depolymerize very slowly in the absence of LPA; moreover, LPA stabilizes the fibrils even below its critical micelle concentration. Neither the amyloidogenic nor the fibril-stabilizing effects of LPA were mimicked by its structural and functional lysophospholipid analogues, showing its selectivity. On the basis of our findings and the observed increase in blood LPA levels in dialysis patients, we suggest that the interaction of LPA with beta2m might contribute to the pathomechanism of dialysis-related amyloidosis.
- Published
- 2009
- Full Text
- View/download PDF
23. Predisposing factors of atelectasis following pulmonary lobectomy.
- Author
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Stolz AJ, Lischke R, Schutzner J, Petrik E, Harustiak T, and Pafko P
- Subjects
- Adenocarcinoma epidemiology, Aged, Bronchoscopy, Carcinoma, Small Cell epidemiology, Female, Humans, Length of Stay, Male, Middle Aged, Pulmonary Disease, Chronic Obstructive epidemiology, Retrospective Studies, Carcinoma, Squamous Cell epidemiology, Lung Neoplasms surgery, Pneumonectomy methods, Postoperative Complications epidemiology, Pulmonary Atelectasis epidemiology
- Abstract
Background: The aims of our study were to investigate postoperative atelectasis complicating pulmonary lobectomy, identify risk factors and evaluate its relationship to other postoperative complications., Material and Methods: From January 2004 to April 2007, 412 patients underwent pulmonary lobectomy. We performed a retrospective analysis of our prospective database. Post-lobectomy atelectasis (PLA) was defined as an ipsilateral opacification of the remaining lobe with an ipsilateral shift of the mediastinum on the chest radiography, requiring bronchoscopy., Results: The incidence of PLA was 6.6%, comprising 29% of all postoperative pulmonary complications seen. There was no statistically significant difference in patient age, gender, ASA score, cardiovascular co-morbidity or operation time for the PLA group versus the group without this complication. Current smokers were at a higher risk for PLA, but this incidence did not reach statistical significance. Chronic obstructive pulmonary disease (COPD) was the only preoperative variable increasing the risk of PLA (p < 0.05). Patients undergoing a right upper lobectomy, either on its own or in combination with a right middle lobe resection, had a significantly higher incidence of PLA when compared with all other types of resection (p < 0.05)., Conclusions: Patients with COPD and those undergoing right upper lobe resection have an increased risk of PLA. In this group of patients we should use pre-operative (cessation of cigarette smoking, treatment of airflow obstruction in patients with COPD), intra-operative (duration of operation) and postoperative (intensive physiotherapy and effective postoperative pain control) measures to decrease the risk of PLA. Although often solitary, PLA is associated with a longer hospital stay.
- Published
- 2009
- Full Text
- View/download PDF
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