bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancement of neutrophil function by the bronchial epithelium stimulated by epidermal growth factor
Authors: Uddin M. , Seumois G. , Lau L. C. , Rytila P. , Davies D. E. , Djukanović R.
Published: December 2007

The bronchial epithelium is an important physical barrier that regulates physiological processes including leukocyte trafficking. The aim of the present study was to elucidate the mechanisms whereby the bronchial epithelium, stimulated by epidermal growth factor (EGF) as part of a response to acute or chronic injury, could activate and chemoattract human neutrophils.

Subconfluent human bronchial epithelial (16HBE) cells were stimulated with EGF to mimic thein vivoevents after injury. The effect of the resulting EGF-conditioned media (CM) was compared with that of basal-CM with respect to neutrophil activation and chemotaxis. Such findings were then confirmed using primary bronchial epithelial cells (PBECs) from healthy volunteers.

EGF-CM from 16HBE cells caused increased expression of CD11b/CD66b and CD62L loss on neutrophils when compared with basal-CM. EGF-CM contained significant neutrophil chemotactic activity involving granulocyte-macrophage colony-stimulating factor and interleukin-8 that was potentiated by leukotriene B4. This was dependent on neutrophil phosphatidylinositol-3-kinase activation and Akt phosphorylation, with partial regulation by phospholipase D, but not mammalian target of rapamycin. Consistent with these observations, EGF-CM derived from PBECs displayed increased chemotactic activity.

The present results suggest that the enhanced chemotactic activity of the epidermal growth factor-conditioned epithelium can enhance neutrophil-mediated immunity during acute injury, while during continued injury and repair, as in chronic asthma, this could contribute to persistent neutrophilic inflammation.
The plasma ammonia response to cycle exercise in COPD
Authors: Calvert L. D. , Singh S. J. , Greenhaff P. L. , Morgan M. D. , Steiner M. C.
Published: December 2007

The plasma ammonia response to exercise in chronic obstructive pulmonary disease (COPD) was examined and the relationship between plasma ammonia concentration and muscle adenine nucleotide metabolism was explored.

In total, 25 stable COPD patients and 13 similar-aged controls underwent incremental and constant-work rate cycle exercise tests. Arterialised venous blood was sampled at rest, at 1-min intervals during exercise and ≤5 min after exercise for ammonia and lactate concentration.

Peak incremental work rate was significantly less in COPD subjects (67±21 W) than similar-aged controls (156±46 W). In COPD and control subjects, plasma ammonia concentration increased during incremental exercise until 2 min post-exercise and then declined by 5 min post-exercise. However, two distinct patterns were seen in COPD subjects. In one group (n = 16), ammonia increased (42.8±3.3 μmol·L−1) by a similar magnitude as the controls (55.5±7.0 μmol·L−1). In the second COPD group (n = 9), no ammonia increase was observed despite a similar lactate increase. Ammonia change with incremental and constant-work rate exercise strongly correlated in COPD subjects. Plasma ammonia increase correlated with muscle inosine-5′–monophosphate formation after constant-work rate exercise.

Plasma ammonia concentration increases during incremental and constant-work rate cycle exercise in chronic obstructive pulmonary disease subjects at lower absolute work rates compared with similar-aged controls. The plasma ammonia response may provide useful information about adenine nucleotide metabolism and, therefore, muscle fatigue during exercise in patients with chronic obstructive pulmonary disease.
Phase I dose escalation study of vinorelbine and topotecan combination chemotherapy in patients with recurrent lung cancer
Authors: Beldner Matthew A , Sherman Carol A , Green Mark R , Garrett-Mayer Elizabeth , Chaudhary Uzair , Meyer Mario L , Kraft Andrew S , Montero Alberto J
Published: December 2007

Background

A platinum doublet is the current standard treatment for good performance status patients with advanced non-small cell lung cancer (NSCLC) and extensive stage small cell lung cancer (SCLC) with good performance status. However, platinum-based treatment may be associated with significant toxicities, therefore alternative platinum-free combinations should be investigated. Topotecan is a topoisomerase I inhibitor that exerts its cytotoxic effect through stabilization of the topoisomerase I-DNA complex. Preclinical data suggests synergy between topoisomerase I inhibitors and mitotic spindle poisons. Considerable hematologic toxicities have been reported with topotecan dosed for 5 consecutive days in combination with vinorelbine. Therefore, the aim of this study was to evaluate the optimal dosage and the maximal tolerated dose (MTD) of topotecan and vinorelbine in patients with relapsed or refractory non-small cell or small cell lung cancer administered on an alternate dosing schedule.

Methods

From February, 2004 to March, 2007 eighteen patients with advanced or recurrent NSCLC or SCLC previously treated with chemotherapy were enrolled. Patients were heavily pretreated with 22% having received at least 3 prior lines of chemotherapy. Vinorelbine was administered at a fixed dose (20 mg/m2) and topotecan at escalating doses (2, 2.5, 3, 3.5, and 4 mg/m2) on days 1 and 8 every 21 days.

Results

The MTD was not reached in any of the 5 cohorts, with only one dose limiting toxicity (DLT) occurring in cohort 4. Non-hematological toxicities were manageable. One patient had a partial response with four patients (27%) achieving stable disease. The median progression-free and overall survival for all patients, were 2.7 months (95% CI: 1.6, 9.1) and 10.5 months (95% CI: 4.2, 22.7), respectively.

Conclusion

Vinorelbine and topotecan administered on days 1 and 8 every 21 days is well tolerated without any DLT seen with previously investigated topotecan schedules. This doublet provides a potentially active non-platinum containing doublet for the treatment of patients with advanced SCLC and NSCLC. Vinorelbine and topotecan should therefore be investigated in subsequent phase II studies at a dose of 20 mg/m2 and 4 mg/m2, respectively.

Trial Registration Number

NCT00287963.
Improved isolation of murine hepatocytes for in vitro malaria liver stage studies
Authors: Gonçalves Lígia A , Vigário Ana M , Penha-Gonçalves Carlos
Published: December 2007

Background

Primary hepatocyte cultures are a valuable tool for the understanding of cellular and molecular phenomena occurring during malaria liver stage. This paper describes an improved perfusion/dissociation procedure to isolate hepatocytes from mouse liver that is suitable for malaria studies and allows reproducible preparation of primary hepatocytes with consistent cell yields and controlled purity.

Results

This protocol is a detailed description of a technique to isolate and culture mouse hepatocytes and represents an improvement over previous descriptions of hepatocyte isolation for malaria studies, regarding three technical aspects: (1) dissociation reagents choice; (2) cell separation gradient and (3) cell purity control. Cell dissociation was optimized for a specific collagenase digestion media. The cell dissociation step was improved by using a three-layer discontinuous gradient. A cell purity check was introduced to monitor the expression of CD95 on hepatocytes using flow cytometry methods.

Conclusion

The procedure described allows reproducible recovery of one to three million hepatocytes per preparation with cell purity of about 90% as determined by FACS analysis. Completion of the protocol is usually achieved in about four hours per preparation and pooling is suggested for multiple preparations of larger number of cells.
Osteopetrotic (op/op) mice have reduced microglia, no Aβ deposition, and no changes in dopaminergic neurons
Authors: Kondo Yoichi , Lemere Cynthia A , Seabrook Timothy J
Published: December 2007

Background

Activation of microglia is a part of the inflammatory response in neurodegenerative diseases but its role in the pathophysiology of these diseases is still unclear. The osteopetrotic (op/op) mouse lacks colony-stimulating factor-1 (CSF-1) and thus has a deficiency in microglia and macrophages. Prior reports have demonstrated that op/op mice deposit amyloid β (Aβ) plaques, similar to those found in Alzheimer's disease. The purpose of these studies was to confirm this and to determine if the lack of CSF-1 affects the development of dopaminergic neurons and the expression of CD200, a known microglial inhibitory protein.

Method

We examined the central nervous system of op/op mice at 30 days, 60 days and 7 months of age and wildtype littermates at 30 days using immunohistochemistry and histochemistry.

Results

We found a decrease in the number of microglia in 1 month-old op/op mice compared to wildtype (WT) littermates as measured by CD11b, CD45, CD32/16, CD68, CD204 and F4/80 immunoreactivity. Aβ plaques were not detected, while the number of dopaminergic neurons appeared normal. The expression of CD200 appeared to be normal, but there appeared to be a lower expression in the substantia nigra.

Conclusion

In contrast to a prior report we did not detect Aβ deposition in the central nervous system of op/op mice at 30 days, 60 days or 7 months of age and there was a normal number of dopaminergic neurons. This indicates that op/op mice may be useful to examine the effects of microglia on neurodegenerative disease progression by breeding them to different transgenic mouse models. In addition, the lack of CSF-1 does not appear to affect CD200 expression by neurons but we did note a decrease in the substantia nigra of op/op and WT mice, suggesting that this may be a mechanism by which microglia control may be attenuated in this specific area during Parkinson's disease.
Internal jugular vein thrombosis in a warfarinised patient: a case report
Authors: Ball Elizabeth , Morris-Stiff Gareth , Coxon Mari , Lewis Michael H
Published: December 2007

Introduction

Internal jugular vein thrombosis (IJVT) is a rare but potentially fatal condition. It usually arises following trauma to the internal jugular vein but is also seen in association with coagulopathies and advanced malignancies as part of a para-neoplastic syndrome.

Case presentation

We report a case of a 44 year old woman with a strong past medical history and family history of thrombotic disease who presented with abdominal pain and ascites. A stage III ovarian carcinoma was diagnosed and she underwent debulking of the tumour. She sustained a peri-operative haemorrhage and required insertion of a central line into the right internal jugular vein. At one month follow-up she presented as an emergency with a left neck mass and painful swallowing. A duplex ultrasound of her neck identified a left IJVT to the level of the brachiocephalic vein which had occurred despite warfarinisation and an INR of greater than 2. She was commenced on intravenous heparin and the swelling resolved over the course of a week.

Conclusion

This case illustrates an unusual presentation of a rare condition. In this case, the precise aetiology is unclear as the IJVT may have been related to a coagulopathy or the presence of advanced malignancy and occurred despite adequate anticoagulation.
Post-translational modifications of histones H3 and H4 associated with the histone methyltransferases Suv39h1 and G9a
Authors: Robin Philippe , Fritsch Lauriane , Philipot Ophélie , Svinarchuk Fedor , Ait-Si-Ali Slimane
Published: December 2007

Specific combinations of post-translational modifications of histones alter chromatin structure, facilitating gene transcription or silencing. Here we have investigated the 'histone code' associated with the histone methyltransferases Suv39h1 and G9a by combining double immunopurification and mass spectrometry. Our results confirm the previously reported histone modifications associated with Suv39h1 and G9a. Moreover, this method allowed us to demonstrate for the first time an association of acetylated histones with the repressor proteins Suv39h1 and G9a.
Nonmuscle myosin II moves in new directions
Authors: Conti Mary Anne , Adelstein Robert S.
Published: December 2007

For many years, analyses of the role of the actomyosin cytoskeleton in many basic cellular processes have centered on actin. Increasingly, however, a number of investigators are examining proteins that are proximal to actin; in particular, nonmuscle myosin II (NMII). Recent experiments have increased our understanding of the role of NMII in three related cellular activities: generation of cell polarity, cell migration and cell-cell adhesion. Progress has been particularly promising thanks to the use of new microscopic, genetic and biochemical techniques. In mammalian systems, generation of transgenic mice and the introduction of specific siRNAs have been useful in deciphering the role of the three different isoforms of NMII: NMIIA, NMIIB and NMIIC. Studies in Drosophila and Aplysia, which are informative model systems for investigating the function of NMII, have also shed light on NMII. Recent work examines the contractile and structural roles that NMII plays at cell-cell boundaries, and both its contractile and actin-crosslinking roles in cell migration. In addition, NMII might also function as a scaffold molecule, anchoring signaling molecules, such as kinases and Rho GTPase guanine nucleotide exchange factors.
The Performance Effects of Complementarities Between Information Systems, Marketing, Manufacturing, and Supply Chain Processes
Authors: Bharadwaj Sundar , Bharadwaj Anandhi , Bendoly Elliot
Published: December 2007

Manufacturing firms are increasingly using advanced enterprise-level information systems to coordinate and synchronize externally oriented functions such as marketing and supply chain and internally oriented activities such as manufacturing. In this paper, we present a model of manufacturing performance that simultaneously considers the effects of a firm's integrated IS capability in conjunction with interfunctional and interorganizational coordination mechanisms. Consistent with the complementarity perspective, we view this specific form of IS capability as enhancing manufacturing's coordination with marketing and supply chain functions to drive manufacturing performance. Additionally, the theoretical model presented here introduces manufacturing-IS coordination, a form of coordination not considered in past research, as a key antecedent to integrated IS capability. The research thus provides a comprehensive framework for examining manufacturing performance in contexts that have been transformed by the use of advanced information systems. The theoretical model is tested using primary data collected from manufacturing firms and matched with objective manufacturing performance data from secondary sources. Results show that a firm's integrated IS capability, as well as the complementary effects of IS capability with manufacturing, marketing, and supply chain processes, are significant predictors of manufacturing performance. These findings are robust to concerns of endogeneity, unobserved heterogeneity, and alternative model specification.
Innovation and the Durable Goods Monopolist: The Optimality of Frequent New-Version Releases
Authors: Sankaranarayanan Ramesh
Published: December 2007

When an improvable durable good (such as packaged software) saturates the market, the seller could be tempted to release new versions too frequently, hurting her profit. A novel contractual device, which I term as a Free New Version Rights warranty (free NVR warranty), can help the seller overcome this temptation. In a two-period game-theoretic model involving a monopolist firm facing heterogeneous consumers, I derive conditions under which a rational monopolist can act suboptimally: She could face a commitment problem and offer the new version, even if doing so lowers her overall profit. Profit is hurt because when consumers expect a new version, (a) fewer consumers buy the initial version, and (b) the monopolist is forced to charge a lower price for the initial version. I show how the free NVR warranty, which requires the monopolist to offer consumers the right to receive the new version for free for a limited period, can solve her commitment problem. This is a new, surprising finding: By bundling new-version rights with the initial version, the monopolist at first appears to be denying herself future revenue. I derive conditions under which this apparently unprofitable action is optimal, which is my main contribution. When free NVR is offered, consumer surplus decreases and social surplus increases. This work extends prior literature on durable goods and the Coase conjecture to innovative durable goods with network externalities. The findings have important practical implications for firms selling new versions of innovative durable goods subject to network effects, as well as for their consumers.
Differences Between Ceftriaxone and Cefotaxime: Microbiological Inconsistencies
Authors: Gums John G , Boatwright D Wesston , Camblin Mark , Halstead Diane C , Jones Mark E , Sanderson Roger
Published: December 2007

Objective:

To review data to determine why pneumococcal isolates appear to be increasingly resistant to cefotaxime, historically regarded as having the same in vitro susceptibility to ceftriaxone, and what this observation might imply clinically.

Data Sources:

Literature was accessed through MEDLINE (1966–October 2007) using the MeSH terms cefotaxime, ceftriaxone, susceptibility, microbial sensitivity tests, antibiotics, pneumococcal infections, Streptococcus pneumoniae. resistance, and cephalosporin resistance. Abstracts and surveillance databases were reviewed and unpublished data were provided by state departments of health and institutions.

Study Selection and Data Extraction:

All articles published in the English language that were identified from the data sources were evaluated.

Data Synthesis:

An experimental model of pneumococcal infection in mice conducted 2 decades ago predicted that the delta T minimum inhibitory concentration (MIC) varied less for ceftriaxone than for cefotaxime. Studies of plasma and serum concentrations show that ceftriaxone remains at a concentration above the S. pneumoniae MIC for 100% of the dosing interval al 12 hours. Types of MIC susceptibility test methods for ceftriaxone and cefotaxime used against S pneumoniae respiratory isolates were found to be similar. Data from state and county health departments found microbiological discrepancies between ceftriaxone and cefotaxime. In areas with high rates of penicillin-resistant S. pneumoniae (PRSP), isolates were twice as susceptible to ceftriaxone versus cefotaxime. Surveillance databases consistently show differences between susceptibility of S. pneumoniae to cefotaxime versus ceftriaxone over time. MIC and pulsed-field gel electrophoresis studies suggest that phenotypic discrepancies may account for ponicillin resistance. Ongoing studies are examining S. pneumoniae isolates at the molecular level to determine the basis of difference in resistance to cefotaxime and ceftriaxone.

Conclusions:

An increase in rates of PRSP and differences in S. pneumoniae isolate susceptibility between ceftriaxone and cefotaxime emphasize the necessity for hospital laboratories to detect these changes as they occur. Clinicians should select the most appropriate agent for patients with S. pneumoniae.
Methotrexate-Induced Papular Eruption Following Treatment of Psoriasis
Authors: Mebazaa Amel , Kenani Nesrine , Denguezli Mohamed , Salem Chaker Ben , Ziadi Sonia , Sriha Badreddine , Belajouza Colandane , Nouira Rafiaa
Published: December 2007

Objective:

To report a case of a diffuse papular eruption following treatment of psoriasis with methotrexate injections.

Case Report:

A 52-year-old woman presented with an extensive flare of psoriasis associated with joint pain, especially in her knees and elbows. She was treated with intramuscular injections of methotrexate 20 mg/wk. Ten hours after the second methotrexate injection, the patient experienced a diffuse pruritic papular eruption located mainly on the limbs. Histology showed foci of dyskeratosis in the mucosal layer and a polymorphic perivascular inflammatory infiltrate of (he papillary dermis, suggesting a drug-induced skin reaction. According to the Naranjo probability scale, the papular eruption was probably caused by methotrexate. The drug was discontinued and papular lesions gradually disappeared.

Discussion:

Methotrexate-induced papular eruption is rarely reported shortly after beginning methotrexate therapy in patients with acute exacerbation of collagen vascular diseases. Methotrexate-induced papular eruption following treatment of psoriasis has not been previously reported.

Conclusions:

The pathogenesis of methotrexate-induced papular eruption in collagen vascular diseases may suggest cutaneous small-vessel vasculitis. In our patient, histology showed aspects of drug-Induced skin reaction without vasculitis. Pathogenesis of methotrexate-induced papular eruption in psoriasis may Involve immune mechanisms other than those of methotrexate-induced cutaneous vasculitis in collagen vascular disease.
Monitoring of Anthracycline-Induced Cardiotoxicity
Authors: Jannazzo Abigail , Hoffman Janet , Lutz Mark
Published: December 2007

Objective:

To review the literature regarding the appropriate monitoring for anthracycline-induced cardiotoxicity.

Data Sources:

A MEDLINE search of the literature was performed (1966–August 2007). Search terms included anthracycline, cardiotoxicity, and monitoring. Additional references were identified through bibliographic reviews.

Data Synthesis:

Anthracycline medications are effective in the treatment of many malignancies but their use is limited by their associated cardiotoxicity. The focus of anthracycline-induced cardiotoxicity prevention has been on monitoring cardiac function during treatment; however, a consensus on the most appropriate way to monitor patients is not available. Most guidelines lack specific details on the appropriate methods of cardiac evaluation and schedule. One guideline that does provide specific recommendations on both the method of evaluation and schedule has been criticized for being too restrictive, costly, and tacking in evidentiary support. The literature is insufficient in evaluation of the predictive value of cardiac function monitoring by echocardiography or radionuclide angiography during anthracycline therapy and the future development of cardiotoxicity, the necessity of baseline cardiac function monitoring, the optimal follow-up cardiac evaluation schedule, and the addition of risk stratification to monitoring schemes.

Conclusions:

Although guidelines are Inadequate to predict and prevent anthracycline-induced cardiotoxicity, until further research is available, following one of the existing guidelines to monitor for this adverse effect is a practical solution.
Employing Rhodobacter sphaeroides to functionally express and purify human G protein-coupled receptors
Authors: Roy Ankita , Shukla Arun Kumar , Haase Winfried , Michel Hartmut
Published: December 2007

G protein-coupled receptors (GPCRs) represent the largest class of cell surface receptors and play crucial roles in many cellular and physiological processes. Functional production of recombinant GPCRs is one of the main bottlenecks to obtaining structural information. Here, we report the use of a novel bacterial expression system based on the photosynthetic bacterium Rhodobacter sphaeroides for the production of human recombinant GPCRs. The advantage of employing R. sphaeroides as a host lies in the fact that it provides much more membrane surface per cell compared to other typical expression hosts. The system was tailored to overexpress recombinant receptors under the control of the moderately strong and highly regulated superoperonic photosynthetic promoter pufQ. We tested this system for the expression of some class A GPCRs, namely, the human adenosine A2a receptor (A2aR), the human angiotensin AT1a receptor (AT1aR) and the human bradykinin B2 receptor (B2R). Several different constructs were examined and functional production of the recombinant receptors was achieved. The best-expressed receptor, AT1aR, was solubilized and affinity-purified. To the best of our knowledge, this is the first report of successful use of a bacterial host – R. sphaeroides – to produce functional recombinant GPCRs under the control of a photosynthetic gene promoter.
Craniospinal malformations in a twelve-year fetopathological study; the efficiency of ultrasonography in view of fetopathological investigations
Authors: Joó József Gábor , Beke Artúr , Szigeti Zsanett , Csaba Ákos , Mezei Gábor , Tóth-Pál Ernő , Papp Zoltán , Papp Csaba
Published: December 2007

A foetopathologiai vizsgálat nagy jelentőségű, hiszen egy következő terhesség vállalásának szempontjait szem előtt tartva – egyebek mellett – az előforduló rendellenesség ismétlődésének esélyeit hivatott megítélni.Célkitűzés:Vizsgálataink céljául a praenatalis ultrahang-diagnosztika hatékonyságának, illetve a terhességmegszakítást követő foetopathologiai vizsgálat eredményének megítélését, elemzését tűztük ki a jelentősebb craniospinalis malformatiók tekintetében.Módszer:Vizsgálataink során az 1995. január 1. és 2006. december 31. között a Semmelweis Egyetem Általános Orvostudományi Kar I. számú Szülészeti és Nőgyógyászati Klinikáján craniospinalis malformatio miatt megszakított 339 terhesség adatait dolgoztuk fel.Eredmények:A vizsgált esetekben az anyai életkor medián értéke 15 és 47 éves szélső értékek között 27 ± 5,8 év volt. 83 esetben (24,5%) terhelő szülészeti-nőgyógyászati vagy genetikai előzmény fordult elő. A vizsgált 339 esetből 231-ben (68,1%) az ultrahangvizsgálattal nyert és a foetopathologiai vizsgálattal igazolt diagnózisok teljesen megegyeztek, 82 esetben (24,2%) részleges egyezés mellett a boncolás további kórismék felállítására adott módot, míg 26 esetben (7,7%) a praenatalis ultrahangvizsgálat, illetve a foetopathologiai vizsgálat eltérő eredményeket igazolt. Ez utóbbi 26 eset felében (13 eset) a vetélésindukció javallatát ultrahangvizsgálattal igazolt hydrocephalus képezte, melyet a boncolás nem erősített meg, illetőleg egyéb craniospinalis rendellenesség(ek) fennállását igazolta.Következtetések:Mivel a hydrocephalus kórismézése esetenként – tekintettel a sokszínű kóreredetre – a többi craniospinalis rendellenességhez képest későbbi gesztációs korban lehetséges csak, kijelenthető, hogy – mérlegelve a foetopathologiai vizsgálatok tükrében igazolódott diagnosztikai hatékonyságot – a hydrocephalus praenatalis ultrahang-diagnosztikáját a többi craniospinalis rendellenességtől külön, azokétól eltérő időbeli és ultrahang-metodikai elvek alapján célszerű értelmezni.
Geotechnical-Acoustical Analysis of Marine Sediments: A Review on the State of The Technology
Authors: Ingram Wayne B. , McMonagle Robert D.
Published: December 2007

The requirement for sub-sea soils data is paramount for the siting of gravity structures, pile founded structures, mobi1 drill rigs, selection of pipeline routes and depths of burial, anchoring of vessels, running of preconductors and a myriad of other associated problems.

Properties of soils that are highly important in a design process are shear strength, water content, grain size distribution, consolidation characteristics and density. A number of investigations have attempted to relate these soil properties to acoustic properties such as compression wave velocity and reflectivity coefficients as part of the ongoing efforts to determine soil foundation properties indirectly.

This paper: a) reviews soil data gathering efforts from conventional boring programs as a demonstration of how ground truth measurements are obtained; b) discusses in-situ tests which develop direct information; and c) present some of the more meaningful efforts at acoustic methods for determining soil parameters including correlations where they exist. The resulting stratigraphic correlations are useful in siting of platforms, routing of pipelines and in determining approximate settlement of structures.
Micellar-Polymer Flooding Projects in the Bradford Field
Authors: Guckert Larry G. , Paynter Warren T.
Published: December 2007

Beginning in 1968 Pennzoil installed and operated two field tests of the Maraflood™ oil recovery process in the Bradford field of Pennsylvania. The oil reservoir tested was the oil-wet, watered-out Bradford Third sand at a depth of 1850 ft.

The initial 3/4-acre inverted five-spot pilot, operated from 1968 to 1970, proved that residual waterflood oil could be mobilized and produced by micellar-polymer flooding. The outgrowth of the technically successful pilot test was a 46.2-acre expanded project adjacent to the pilot. The expansion, Special Project No. 7, was developed in 1970 and placed on injection in 1971. Through July 1981, the project has recovered 208,000 bbl of oil, equivalent to 4500 bbl per acre or 300 bbl per acre-ft. Ultimate oil recovery is projected at 218,000 bbl or 52% of the oil in-place following waterflood.

Because of the encouraging results of the previous field tests, Pennzoil started work in 1979 on a 220-acre development in the same area. This development, Special Project No. 8, was self-certified under the DOE front-end incentive program in March 1980. A staggered line drive pattern containing 126 production wells and 57 injection wells was developed in 1980 and 1981. Injection of micellar solution will begin in January 1982, and will be followed by three years of polymer injection. Fluid injection will be concluded by 1990. Oil recovery from the 220-acres is estimated at one million bbl. The cost to develop and produce a barrel of oil (1981 $) by the Maraflood process in the current project is estimated at $27 before taxes (local, federal income and excise tax) and royalty.
A Comprehensive Model for Injectivity Decline Prediction During PWRI
Authors: Paiva R. , Bedrikovetsky P. , Furtado C. , Siqueira A. G. , de Souza A. L. S.
Published: December 2007

Injectivity decline is a chronicle disaster during produced water re-injection (PWRI); the phenomenon has been widely reported in the literature for North Sea, Gulf of Mexico and Campos Basin fields. The damage happens due to solid and liquid particles in the re-injected water. The injectivity decline prediction is important for planning and design of PWRI, of injected water treatment and of well stimulation procedures. The reliable prediction should be based on mathematical modelling using well injectivity index history and laboratory data.

The mathematical models for deep bed filtration of particles and for external filter cake formation have been developed and adjusted to coreflood and well data by numerous authors (Sharma, Khatib, Wennberg et. al.). Here we add modelling of external cake erosion during well closing by the growing cake and filling the well by the erosion particles and develop a comprehensive model.

The comprehensive model predicts very peculiar injectivity index (II) curve: initial II increase due to displacement of oil by less viscous water, slow II decline due to deep bed filtration, fast II decrease during external filter cake formation, II stabilization due to cake erosion during the rat hole filling by the eroded particles and further II decrease during well column filling by erosion products.

The model is implemented in Excel; the software SPINSimulates and Predicts the INjectivity.

We present in details the history matching for three injectors (field X, Campos Basin, Brazil), showing good agreement between modelling and well data. The obtained values of injectivity damage parameters lay in the same rage intervals as those calculated from laboratory corefloods.
Address of Guillermo Rodriguez-Eraso, President of Lagoven, S.A. to the Second Joint Symposium on Enhanced Oil Recovery
Authors: Rodriguez-Eraso Guillermo
Published: December 2007

It is an honor and a pleasure to be here today and be able to address for the second year in a row the distinguished audience gathered for the occasion of the Joint Symposium on Enhanced Oil Recovery.

Venezuela and the United States have a long history of fruitful commercial relations which have been important to both of our countries, and seem destined to become increasingly so. Even with a successful program of energy conservation and diversification, the United States will likely continue to have to rely on large quantities of imported oil. In this respect the volumetric size, geographical proximity and traditional reliability of Venezuela's oil reserves suggest that it will remain an important oil export supplier for many decades to come.

Until a few years ago, we were the United States’ principal foreign oil supplier. Although Saudi Arabia now ranks first, Venezuelan oil fills an important share of your oil requirements. In 1980, direct exports to the United States averaged nearly 500,000 barrels of oil per day, more than half of which were refined products. When Venezuelan crude oil that is refined in the Caribbean and then shipped to the United States is included, about half of Venezuela's 1.8 million barrels per day of exports comes to this country.
Economics of in Situ Combustion - The Bellevue Field Bossier Parish, Louisiana
Authors: Pusch William H. , Garvey John M.
Published: December 2007

The ever-changing economic status of the world's oil supply has changed the industry's outlook on future petroleum reserves to the point that new incentives have arisen to explore new recovery techniques that once were far too uneconomical to conduct. Ten years ago, Cities Service Company pioneered an Enhanced Oil Recovery Project to maximize production from a shallow viscous oil reservoir in which primary and secondary recovery techniques had produced only 10% of the original oil in place. Therman recovery, which is the EOR process used by Cities Service in the Bellevue Field, has long been recognized as an effective means of increasing the recovery of high viscosity crude. However, enhanced recovery techniques are plagued with the problems of low recovery and high operating costs. This paper is directed toward discussing some of those costs.
The Influence of Pore Coordination on Petrophysical Parameters
Authors: Yuan Herbert H.
Published: December 2007

Using simple models of pore systems in conjunction with percolation theory concepts, relationships between the residual oil saturation at very low flooding rates and three petrophysical parameters, the porosity, the formation resistivity factor and Archie's lithologic exponent are found. Experimental data using air/liquid countercurrent imbibition along with routine petrophysical measurements on a set of clean, well-sorted sandstones and various carbonates confirm these relationships. Empirically, the best correlation for the residual oil saturation is with the porosity, although the formation resistivity factor also provides a good correlation.
Use of Chemical Salt Precipitation Inhibitors to Maintain Supersaturated Salt Muds for Drilling Salt Formations
Authors: Earl S. L. , Nahm J. J.
Published: December 2007

Five commercial salt inhibitors were laboratory tested in NaCl solutions to evaluate their effectiveness in maintaining salt (NaCl) saturations over the temperature ranges encountered from the bottom of the hole to the surface when drilling through salt formations. The effect of salt inhibitors was also studied in NaCl solutions with high Ca++ and Mg++ contamination. Three of the inhibitors were found to be effective in maintaining a supersaturation condition while two were not. Effectiveness was shown to be significantly reduced in the presence of high hardness.

The test results were successfully applied to a drilling program in the Williston Basin to eliminate salt zone washouts with the use of a supersaturated salt mud. Comparison of caliper logs and cement bond logs from previously drilled wells to those of the test wells shows significant reduction in hole enlargement through the salts and improvement in the quality of the cement bond.
Adsorption of Water-Soluble Polymers on High Surface Area Clays
Authors: Ahmed H. , Glass J. E. , McCarthy G. J.
Published: December 2007

The adsorption of water-soluble polymers, predominately of the polysaccharide type, on attapulgite, bentonite and berea sand/bentonite (15 wt,%) agglomerated substrates and on deflocculated bentonite suspensions has been conducted. In the agglomerated substrate studies the molecular weight of derivatied polysaccharides was an important factor; the lower the molecular weight the greater the adsorption. Molecular weight was not important in adsorption on deflocculated bentonite substrates.

In the adsorption of underivatized, non-ionic polysaccharides, chain rigidity influenced by the positional bonding between repeating pyranosyl units was important. The greater the rigidity of the chain, the higher the adsorption, which occurred on the exterior of the bentonite particles. Ether linkages either in a totally synthetic polymer (PEO) or appendaged to a polysaccharide to facilitate aqueous solubility promote penetration of the bentonite interlayer sites and increase interplanar spacings. Despite high adsorption values, poly (ethylene oxide) (PEO) exhibits the greatest regularity along the clay axis. Polysaccharides (PS) with a critical molar substitution of ether linkages adsorb less than PEO but significantly increase the interplanar spacing. The difference in behavior between PEO and PS ethers is presumably due to the inability of ether linkages appendaged to a PS chain to assume, or bring the PS chain into, an interfacially flat configuration in the matrix.

Several interesting observations on the adsorption of anionic W-SPs from high salinity solutions have been made and indicate the need for additional studies.
The Effects of Capillary Pressure on Immiscible Displacements in Stratified Porous Media
Authors: Yokoyama Yoshio , Lake Larry W.
Published: December 2007

Reservoir mixing that occurs during a fluid displacement in a heterogeneous permeable medium could be an important factor in many secondary oil recovery processes. In a stratified medium, mixing may occur longitudinally or in the transverse direction from adjacent layers. One of the greatest causes of mixing in immiscible displacements, capillary imbibition, is described in this paper.

To aid in interpretation and scaling of capillary imbibition effects, three dimensionless numbers and two dimensionless functions are introduced. These are a dimensionless time, a transverse capillary number, a longitudinal capillary number, a heterogeneity function and the Leverett j-function. Through computer simulation these quantities were verified to be accurate measures of capillary mixing in a stratified medium. A pseudo-function approach is also presented by which the vertical mixing phenomenon in a stratified medium may be described in a lower dimension simulation.

Although a stratified model is the simplest form of reservoir heterogeneity, the approach used and results obtained in this study should provide a basis for analyzing fluid displacement in more complicated reservoirs.
A Theoretical Analysis of Viscous Crossflow
Authors: Zapata Vito J. , Lake Larry W.
Published: December 2007

A theory predicting fluid flow in a stratified reservoir considering the affects of viscous crossflow is presented. The development of equations accounts only for crossflow due to pressure gradients formed by the displacing (injected) and displaced (initial) fluids having unequal mobilities; all other forces initiating flow (vertical or horizontal) are considered negligible. The primary simplifying assumption requires the transfer of material between two or more layers to be instantaneous; the assumption is usually referred to as vertical equilibrium (VE). In theory, the equations describing flow are applicable to an arbitrary number of layers, arbitrary initial and injection conditions, arbitrary phase properties affecting flow, and encompasses fractional flow theory applied to water-oil displacements as well as enhanced oil recovery processes. At present the development is restricted to two phases and two components in the injected phase with no partitioning of material between phases.
An Analytical Pattern-Flood Model
Authors: Hagoort J.
Published: December 2007

A new pattern-flood model has been developed for the calculation of flooding efficiencies of plane and pseudo-plane floods. Plane and pseudo-plane floods are flooding processes in plane reservoirs that can be described mathematically by two-dimensional flow equations.

The model is an extension and generalisation of the ‘stream tube-model’. It assumes the flow and saturation distribution in the areal plane to be given by a known simple fluid-fluid displacement in which displacing and displaced fluid are separated by a sharp interface. The mobility ratio of this sharp-interface pattern flood may have any value, and thus need not be unity as in the case of the stream tube models.

It is shown that under this assumption plane and pseudo-plane floods can be described mathematically by one-dimensional equations similar to the equations for linear floods. For the solution the following is required: i. the sweep-efficiency of the sharp-interface pattern flood and ii. a fractional flow function, which depends on (pseudo) relative permeabilities and fluid viscosities.

As an illustration, we have calculated flooding efficiencies in a five-spot for the folowing cases: (i) a unit-mobility-ratio waterflood in a stratified reservoir, (ii) a unit-mobility-ratio waterflood in a stratified reservoir with a hydraulically fractured injection or production well, and (iii) a tertiary flood in a homogeneous reservoir.
Operating Experiences With Centrifugal Compressors for High Pressure Gas Injection in the Arun Field
Authors: Kendrick William B. , Berlim Wimin
Published: December 2007

The Arun Gas Field in Indonesia, has been in operation since May, 1977. This paper discusses gas compression and other facilities required to produce one of the largest gas-condensate fields in the world. The unusually high flowing temperatures and pressures associated with the large gas volumes required for the project called for special considerations in the application of centrifugal compression for the gas cycling phase of the project. The gas stream from the separation station provides the volume required to maintain design capacity at the PT Arun LNG Facilities located nearby. The remainder of the gas stream is diverted for re-injection into the Arun Reservoir. The compression facilities consist of three separate power trains operating in parallel. Each train is made up of four stages of centrifugal compression driven by a gas fired turbine site rated at 28,000 BHP. Current injection rate is approximately 300 MMSCF/Day at a surface pressure of approximately 7100 psia. With several years of operating experience now history, this paper also describes several design modifications required early in the project and discusses the causes and solutions to several operating problems. Operating and performance data is provided to illustrate characteristics of the equipment utilized.
A New Method for Sand Control and Well Stimulation in Unconsolidated Dirty Sands
Authors: Aslesen Kerby S. , Short Charles John , Terwilliger P. L.
Published: December 2007

A new completion technique has been developed which allows unlimited drawdown and improves productivity in wells completed in unconsolidated formations containing shales and clays. Historically, producing oil and gas from such reservoirs has been limited by rate-dependent sand production and fines migration which resulted in near wellbore formation plugging. This technique eliminates the problems of sand production and fines migration by artificially consolidating a volume of reservoir sand near the wellbore. The consolidation is resistant to high temperature, chemical attack, and degradation resulting from high velocity fluid flow. Additionally, porosity and permeability in the consolidated volume of reservoir sand are improved as a result of irreversible dehydration of clays.
Evaluating Fissured Formation Geometry from Well Test Data: a Field Example
Authors: Gringarten Alain C. , Burgess Trevor M. , Viturat Didier , Pelissier Jean , Aubry Michel
Published: December 2007

The paper illustrates, using a field example, how well test data can be used to evaluate matrix block size and fissure volume in fissured reservoirs. The method is based on type-curve analysis with a recently published type-curve for double porosity reservoirs, and is applied to two tests on the same well, performed at a few years interval, with reservoir pressure above and below the bubble point, respectively. Detailed analysis of the two tests is presented, that yields consistent values for fissuration parameters, ω and λ, although pressure behavior during the tests is very different. Interpretation results were used as inputs to a numerical reservoir simulator, which was then calibrated against actual performance history to yield the size of the matrix blocks. The result was in excellent agreement with that obtained from λ, and with available geological, information.
Fracture Detection by Circumferential Propagation of Acoustic Energy
Authors: Setser Gordon G.
Published: December 2007

An acoustic logging tool that propagates waves circumferentially around the borehole wall is described. This tool, The Circumferential Acoustic Device (CAD), shows excellent promise for the detection of vertically-inclined fractures, for the measurement of shear wave velocity, and for the resolution of thinly interbedded zones. The CAD is a four-arm pad tool. Appended to one pair of opposite arms are cylindrical PZT transducers that act as transmitters. Similarly, the other pair of arms have transducers appended that act as receivers. Acoustic energy travels circumferentially between transmitter and receiver as compressional mud waves and as refractively-coupled formation waves. The formation waves are identified as p-, s-, and pseudo-Rayleigh (pR) waves. Absorbing material is used to preferentially attenuate the mud waves and thereby enhance the formation wave content of the received acoustic wavetrain.

We have used the CAD to log open-hole wells in the Williston Basin. The zones logged are primarily tight limestone, have no mudcake, and have a p-wave velocity of around 18,000 ft/sec. The CAD is found to delineate fractured from non-fractured zones through the attenuation of the pR-waves. These results are verified by comparing CAD well-logs to core.

The CAD is potentially useful for making s and pR-wave velocity measurements, and for sorting out the elastic moduli of strata describable as transversely isotropic. In a transversely isotropic medium the sand pR-wave velocities as measured from CAD logs depend on the C55 elastic constant. Thus the CAD gives unique elasticity information since the more conventional acoustic tools would measure s-wave velocities that depend on C44.
An Offshore Storage And Loading System
Authors: Floyd Claude William
Published: December 2007

An offshore loading system needs platform production storage to be efficient. Without storage a platform can only load a tanker at its producing rate, and production must cease when no tanker is connected.

Storage in a concrete platform requires a carefully-designed ballast-water system to maintain a proper pressure balance. The ballast system is designed to handle production into storage and tanker loading from storage simultaneously or separately.

Since the ability of a tanker to moor and load is weather-dependent, storage is necessary for production to continue when seastates exceed mooring limits.

The single-point-mooring buoy must be designed for maximum safety and maximum capability of accepting tankers in heavy seas.

The mooring and loading of tankers presents an unusual challenge to seamanship. The tankers themselves have non-standard design features to improve loading efficiency in the North Sea.