bluuebunny/crossref_metadata_2025_split huggingface dataset:
Orientation of Gingival Fibroblasts in Simulated Periodontal Spaces in Vitro Containing Collagen Gels
Authors: Fernyhough W. , Aukhil I. , Link T. 
Published: March 2012

The present study examined the orientation of cultured human gingival fibroblasts in simulated periodontal spaces in vitro containing three dimensional hydrated collagen gels. Extracted human teeth were root planed followed by root resection and root canal instrumentation. The middle and cervical thirds of each root were cut transversely to create 600μm thick sections. Cortical bovine bone was cut, sectioned, and contoured to create bone rings 600 μm thick with an internal diameter large enough to accommodate a root slice leaving a circumferential space varying from approximately 0.1 to 1.0 mm. Root slices and bone rings were incubated in an enzyme solution to remove all remaining soft tissues and then completely demineralized in EDTA (18%) for 72 hours. Human gingival fibroblasts (HGF) were plated to confluency in tissue culture dishes. The dentin slices were then gently placed over the HGF monolayer along with bone rings around them to create simulated periodontal spaces. Five days later, when initial cell attachment to the dentin and root slices had occurred, a collagen gel was poured in the space. The cultures were maintained for six weeks and were then processed for transmission electron microscopy.The HGF appeared to have formed multilayered cell sheets extending from the periphery of the root slices to the inner surface of bone rings. The HGF had apparently attached to both the bone and root surfaces. There was a close interaction of cells with the matrix fibrils of the gel. The cells and matrix fibrils were oriented parallel to each other. The present findings suggest that HGF grown in simulated periodontal spaces containing a collagen gel in vitro can form oriented, multilayered cell sheets and some degree of physical rearrangement of matrix fibrils occurs during this process.
Rapidly Progressive Periodontitis
Authors: Murro Carlo Di , Nisini Roberto , Cattabriga Marcello , Simonetti‐D'Arca Adele , Moli Soccorsa Le , Paolantonio Michele , Sebastiani Laetitia , D'Amelio Raffaele 
Published: March 2012

In the last few years several bacteriological and immunological studies have investigated the role of bacteria and immune defects in order to establish the etiopathogenesis of periodontal disease. With regard to the immune system, a defect in polymorphonuclear neutrophil (PMN) Chemotaxis has been frequently reported in patients with rapidly progressive or juvenile periodontitis.The purpose of this study was to investigate in five patients with rapidly progressive periodontitis and normal Chemotaxis of peripheral blood PMNs the presence of Chemotaxis inhibitory activity in gingival fluid and to relate such activity to three types of bacteria, often involved in rapidly evolving periodontal lesions, that are able to inhibit in vitro PMN Chemotaxis: Bacteroides gingivalis, Capnocytophaga sp., and Actinobacillus actinomycetemcomitans. We found strong inhibitory activity in three of these patients. This activity was consistently associated with the finding of B. gingivalis in gingival pockets. We cannot rule out, however, that other substances not of bacterial origin could be responsible for such inhibitory activity. The strict association with B. gingivalis, known to secrete blocking factors, is highly suggestive, although this data must be considered preliminary.
Periodontal Wound Healing in the Absence of Periodontal Ligament Cells
Authors: Aukhil I. , Pettersson E. , Suggs C. 
Published: March 2012

This experiment was designed to study the ability of mucoperiosteal flap connective tissue to form new attachment on partially demineralized roots as well as nondemineralized roots in a wound‐model where periodontal ligament (PDL) cells are absent, and ingrowth of bone granulation tissue is controlled.After reflecting mucoperiosteal flaps, bone was removed circumferentially around the distal root of mandibular second premolars and the mesial root of mandibular third premolare in five beagle dogs. The roots were completely denuded from the cementoenamel junction to the apex and curetted to remove PDL and cementum. Following root canal filling, the denuded roots on one side were conditioned with citric acid while the contralateral roots served as controls. To prevent bone‐derived granulation tissue from contacting denuded roots, sheets of Nuclepore® membrane were placed over the exposed bone margins and secured in place with steel ligatures. The flaps were coronally positioned and sutured. Histologic examination was made after three months of healing accompanied by regular plaque control. Both the experimental (acid conditioned) and control roots showed epithelium extending into the apical third of denuded roots and root resorption confined to the root apices. Some experimental specimens showed connective tissue adhesion in the apical third of roots without any new cementum or oriented fibers. Inflammatory cell infiltrate was seen extending to the apical third of denuded roots in both groups. In this model, the flap connective tissue cells failed to form new cementum and inserting fibers. Whether this was the result of inflammation and epithelial downgrowth or the inability of flap connective tissues to form new attachment could not be concluded from the study.
Recurrent Periodontal Disease and Bacterial Presence in the Gingiva
Authors: Pertuiset J. H. , Saglie F. R. , Lofthus J. , Rezende M. , Sanz M. 
Published: March 2012

Previous investigations have shown that, in biopsies taken from untreated sites of periodontitis, bacteria were present between the epithelial cells and within the connective tissue. In the present study we have examined Gram‐stained sections of diseased gingival sites where the disease had recurred after surgical periodontal treatment. The six subjects chosen for the study were patients who had undergone surgical therapy for the treatment of periodontitis and who, upon subsequent recall visits, showed evidence of at least one site recurrent after treatment as detected by bleeding on probing and increased pocket depth of 5 mm or more. A normal control site from the same patient was chosen, preferably contralaterally, showing positive response to treatment with no signs of disease. Sections were stained with either hematoxylin and eosin for tissue survey or Gram for assessment of bacteria and examined by light microscopy. In many specimens, the bacterial nature of Gram‐stained material was substantiated. Preliminary results showed a significantly increased number of bacteria in the refractory sites when compared with control sites which responded positively to treatment.The results of this investigation provided further evidence that bacterial presence inside the periodontal tissue may be an important pathogenic factor in periodontal disease.
Clinical Effects of Electromagnetic Stimulation as an Adjunct to Periodontal Therapy
Authors: Steffensen B. , Caffesse R. G. , Hanks C. T. , Avery J. K. , Wright N. 
Published: March 2012

The clinical effects of electromagnetic stimulation (EMS) on periodontal soft tissues and alveolar bone level were studied among 23 patients. The sides of the arch to receive EMS were randomly selected and exposed for a period of eight weeks following periodontal surgery. The contralateral control sides received surgery only. The electromagnetic signal was a multiple pulse signal with 21 asymmetrical quasirectangular pulses per burst and a burst frequency of 16.9 Hz. The peak magnetic field strength reached 0.46 Gauss. Changes from baseline in clinical attachment level, probing depth, and radiographic alveolar bone level were assessed at six, 12, and 18 months postsurgically.A greater gain of clinical attachment level following EMS was observed only for pockets with initial depth of 1 to 3 mm. There were no consistent differences between test (EMS) and control sides in the change of clinical attachment level or probing depth for pockets deeper than 4 mm. Radiographically, the test sides demonstrated statistically significant gain of alveolar bone level compared with the control sides at six months following surgery. Hereafter, the rates of change were similar in the stimulated and unstimulated sides, and the total gain of alveolar bone level remained greater in the test side throughout the observation period.Within the limitations of this study, it was concluded that electromagnetic stimulation does not promote gains in clinical attachment or alveolar bone level to the extent that it can be recommended as an adjunct to conventional periodontal therapy.
Ultrastructural Changes of Subepithelial Capillaries Following Graft Epithelialization
Authors: Nobuto Takahiro , Imai Hisao , Yamaoka Akira 
Published: March 2012

This study investigated architectural changes in the nourishment‐providing capillaries beneath the epithelium that accompany graft epithelialization. A total of 77 mongrel dogs underwent free gingival autografts involving the maxillary canine and its attached gingiva. Comparative investigations relating the architectural transformations and endothelial permeability of the capillaries were made histopathologically, with graft epithelialization as an indicator.Microscopic findings revealed that the subepithelial capillaries transformed from loop structure into glomus‐like structures. The endothelium changed ultrastructurally from the continuous type to the fenestrated. This occurred during the most active graft epithelialization phase. By the time the epithelium of the graft had matured, the fenestrated microvascular structure reverted to the continuous type and changed from a glomus‐like structure to a network capillary system. However, by the 84th postoperative day, the subepithelial capillaries, still exhibiting network structure, had not yet returned to the loop structure indigenous to the gingiva.Observations indicated that transformation of the structure of the nourishment‐providing capillaries was attendant to and simultaneous with the changes brought about by graft epithelialization.
New Attachment Achieved by Guided Tissue Regeneration in Beagle Dogs
Authors: Caffesse R. G. , Smith B. A. , Castelli W. A. , Nasjleti C. E. 
Published: March 2012

This study tested the effects of using a Gore‐Tex periodontal material on new connective tissue attachment in beagle dogs with natural Periodontitis. Seven female beagle dogs with advanced Periodontitis were selected and given thorough root debridement. Under general anesthesia four weeks later, mucoperiosteal flaps were raised involving all mandibular premolars and first molars. Gore‐Tex periodontal material was adapted to all premolare, and the flaps were sutured tightly, keeping the material covered. The first molars acted as controls, receiving only surgery. Some material was removed in one month, while other materials were removed eight to 10 weeks after surgery. All dogs were sacrificed at three months. After processing, descriptive histology and histometrics were carried out, evaluating new connective tissue attachment, bone response and epithelial downgrowth.Results were statistically analyzed, using paired t tests. They showed new connective tissue attachment with cementum deposition in areas where the material was used. Also, the epithelial downgrowth was reduced in these areas. In the controls, minimal connective tissue attachment was found, with the area healing by a long junctional epithelium. Statistical analysis showed significant differences (P < 0.05) favoring experimental areas both in the increase of new connective tissue attachment and in the decrease of epithelial downgrowth. No differences were found between areas where the material was removed in one month or left longer in place. No difference in bone response was found. Gore‐Tex material was effective in blocking gingival epithelial downgrowth and connective tissue proliferation, promoting new attachment according to the principle of “guided tissue regeneration.”
Waterflood Management Based on Well Allocation Factors for Improved Sweep Efficiency: Model Based or Data Based?
Authors: Shahvali M. , Shirzadi S. G. , Ballin P. R. , Ziegel E. 
Published: March 2012

Abstract
Streamline-based methods provide an effective model-based tool for assessing flow patterns and well allocation factors. This type of diagnostic information is a key enabler in model-based waterflood management. Alternatively, data-driven techniques are available for waterflood diagnostics and estimating injector/producer connectivity, including one based on the Capacitance-Resistivity Model (CRM). The purpose of this paper is to compare the results of these two complementary approaches using a sector area representative of a mature field.
In the first part of the paper, a workflow which allows a comparison of the streamlines and the CRM methodologies, regardless of the uncertainty of the simulation model, is introduced. The limitations of both approaches are discussed.
In the second part of the paper, the CRM data-driven approach is used to determine the statistically significant allocation factors for the injection and production data from the sector reservoir model, and they are compared with the streamline-based factors. The results and guidance for the integration of the two approaches are presented.
Creating Digital Thermal EOR Projects Using Wireless Technology and New Data Integration Solutions
Authors: Angelo Christopher , Mershon Kevin 
Published: March 2012

Abstract
Technology over the last decade has revolutionized information systems and how data are collected and shared in our daily lives. An extraordinary amount of data is being collected, stored, analyzed, and shared every day. The oil and gas industry is no stranger to data collection and analysis, but data acquisition and management has historically been complex and expensive and, thus, slowly implemented. With recent advances in hardware and software, costs have plummeted to yield rapid implementation of sophisticated monitoring, analysis, and easy sharing of information in oilfield projects.
The thermal-enhanced oil recovery (TEOR) process requires constant monitoring and analytical management of wells and facilities. This data management process requires large amounts of data to be collected, correlated and acted-upon on a very frequent basis, resulting in easily-recognizable business benefits by oil producers. This paper reviews the use of wireless instrumentation and integrated data collection systems for digitally managing oilfields, with one such implementation being reviewed.
An independent oil producer using wireless instrumentation and state-of-the-art data integration technology has beenoperating the largest Wireless HART network in the United States since the beginning of 2010. This independent oil producer is wirelessly monitoring all of their steam injectors in three thermal oil fields located in western Kern County, California.
Monobore Well Design: Utilizing Technology to Improve Well Execution Efficiency
Authors: Randell Ben 
Published: March 2012

Abstract
Chevron has piloted a new well design for near-vertical steamflood producers in the MWSS field. This new design simplifies the well construction process by replacing two hole sizes and two casing strings with a single hole size and single combo casing string. Doing so requires utilizing technologies such as: expansion joint, annular casing packer and cementing stage tool to allow only the top portion of the casing string to be cemented while the slotted casing remains un-cemented.
This well design has been piloted in MWSS to replace the previous two-string slotted liner well design. At the time of writing, 26 monobore wells have been installed incident-free and all are a technical success. Chevron has committed to 11 more monobore wells in the nearby Cymric field and is planning to adopt the design throughout its San Joaquin Valley (SJV) fields, with over 70 wells expected by Q3 2012.
The monobore design has reduced overall well construction cycle time by 25% and capital expenditure has also been reduced. The implications to well deliverability and accelerated production are obvious and Chevron has begun to increase the well count in specific campaigns to reflect the time and cost savings. Furthermore, the monobore design increases the probability of logs and casing reaching bottom in a single trip, and enhances formation evaluation to include upper zones that would have been behind casing with the previous design. By implementing the monobore design, Chevron will be able to extend the economic development life of the region.
The subject matter will be of interest to other operators drilling similar, shallow, low-pressure, heavy-oil reservoirs.
Detecting Shale Discontinuity between Different Layers Using Waterflood Tomography
Authors: Lin Yenting , Ortega Antonio , Tafti Tayeb Ayatollahy , Ershaghi Iraj 
Published: March 2012

Abstract
This paper presents a novel signal processing method to detect the existence and location of shale discontinuities between layers with distinct permeabilities by using only waterflood injection and production data. Continuing the work by Y. Lin, et. al (SPE-132699-PP), we use a new waterflood tomography concept to analyze cross-flow behavior among different layers and estimate the hydraulic transmissivity via tomography mapping. With designed injection rates, we estimate the response times at the producers by monitoring production rates. The response time represents the ‘cost’ for the fluid to travel between well-pairs and we can use it to model the virtual path through different layers. We consider the case of waterflooding in the presence of permeability contrast in different layers. The fluid in the low permeability layer tends to flow through the shale discontinuity to the higher permeability layer thus forming vertical `high permeability cross-flow channels between the wells. With the response time, we are able to identify these 3D high perm channels to estimate the location of shale discontinuities causing the cross-flow. To the best of our knowledge, we are the first to propose this waterflood tomography method. Without significantly affecting daily operation and without the cost associated with tracer testing and seismic tomography, our technique only involves applying scheduled changes to the injection rates and analyzing the relationship between these changes and those in production rates.
To demonstrate the application, using a commercial simulator, we build a double layer reservoir model with different permeabilities. We test a line drive case with injectors and producers having perforations in both lower and upper layers. By applying our designed injection and shut-in schedule, we show our method can provide a very accurate estimate of shale discontinuity location by recording accurate response times between well-pairs.
New Method in Evaluating the Formation Damage in Laboratorial Investigations
Authors: Ghofrani R. , Zhang Y. , Bosch V. 
Published: March 2012

Abstract
Today oil and gas wells are drilled using mostly water-based drilling fluids. The introduction of both the mud solids and polymers into the formation, the changed values of fluid's saturation in the pore spaces, the reactions between the filtrate and the pore contents and/or the matrix materials result in a reduction of the formation's original permeability; thus the formation is damaged.
World wide the range of formation damage has been determined by damage ratio DR. The value of damage ratio is mainly affected by the layer with the lowest permeability (filter cake). Therefore the tested cores have to be evaluated in general as damaged over the whole length, which does not correspond with the real case under reservoir conditions.
In this paper a new defined damage ratio has been used to evaluate the core damage using different drilling fluids. It could be demonstrated, that the new defined damage ratio is an expedient value for rocks with excellent original permeabilities, which allows to determine a reliable extent of the damaged zone of the tested core.
Furthermore, it could be verified that the extent of the damaged zone depends upon the contact time between the drilling fluid and the core, and also upon the stability conditions of the used drilling fluids.
Long-Term Safety, Tolerability, and Weight Loss Associated With Metformin in the Diabetes Prevention Program Outcomes Study
Authors:   The Diabetes Prevention Program Research Group
Published: March 2012

OBJECTIVE
Metformin produced weight loss and delayed or prevented diabetes in the Diabetes Prevention Program (DPP). We examined its long-term safety and tolerability along with weight loss, and change in waist circumference during the DPP and its long-term follow-up.

RESEARCH DESIGN AND METHODS
The randomized double-blind clinical trial of metformin or placebo followed by a 7–8-year open-label extension and analysis of adverse events, tolerability, and the effect of adherence on change in weight and waist circumference.

RESULTS
No significant safety issues were identified. Gastrointestinal symptoms were more common in metformin than placebo participants and declined over time. During the DPP, average hemoglobin and hematocrit levels were slightly lower in the metformin group than in the placebo group. Decreases in hemoglobin and hematocrit in the metformin group occurred during the first year following randomization, with no further changes observed over time. During the DPP, metformin participants had reduced body weight and waist circumference compared with placebo (weight by 2.06 ± 5.65% vs. 0.02 ± 5.52%, P &lt; 0.001, and waist circumference by 2.13 ± 7.06 cm vs. 0.79 ± 6.54 cm, P &lt; 0.001 in metformin vs. placebo, respectively). The magnitude of weight loss during the 2-year double-blind period was directly related to adherence (P &lt; 0.001). Throughout the unblinded follow-up, weight loss remained significantly greater in the metformin group than in the placebo group (2.0 vs. 0.2%, P &lt; 0.001), and this was related to the degree of continuing metformin adherence (P &lt; 0.001).

CONCLUSIONS
Metformin used for diabetes prevention is safe and well tolerated. Weight loss is related to adherence to metformin and is durable for at least 10 years of treatment.
Application of the ProteomeLab™ PF2D protein fractionation system in proteomic analysis for human genetic diseases
Authors: Wang Li , Zhong Nanbert 
Published: March 2012

Abstract
Proteomic analysis has been widely used in elucidating the mechanism of diseases. As a classical proteomic approach, two-dimensional gel electrophoresis (2DGE) has been commonly applied in finding differentially expressed proteins through a first dimension of separation by the isoelectric point (pI) of proteins and a second dimension of separation according to the molecular weight (MW) of proteins. Compared to 2DGE, a recently developed commercial system from Beckman Coulter, the two-dimensional protein fractionation (PF2D), separates proteins according to the pI of proteins in the first dimension followed by a second dimension of separation according to the degree of protein hydrophobicity. As a liquid-based fractionation system, PF2D could facilitate the extraction and separation of broader protein categories and improve reproducibility and quantification as well as be less labor-intensive, which are usually identified as limitations of a gel-based 2DGE platform. This review evaluates the applications of the PF2D system and discusses the perspectives and advantages of PF2D in the investigation of cancer and genetic disorders and in protein mapping in human biological fluids and cell cultures.