bluuebunny/crossref_metadata_2025 huggingface dataset:
Increasing Influenza Immunization for Long‐Term Care Facility Staff Using Quality Improvement
Authors: Sand Kelly L. , Lynn Joanne , Bardenheier Barbara , Seow Hsien , Nace David A.
Published: October 2007

OBJECTIVES: To improve staff immunization rates for influenza in long‐term care facilities (LTCFs).

DESIGN: A quality improvement project.

SETTING: LTCFs ranging in size from 50 to 2,000 beds.

PARTICIPANTS: Staff members at facilities.

MEASUREMENTS: Change in staff influenza immunization rate.

RESULTS: Of the 13 nursing homes involved, 11 improved their staff influenza immunization rates; nine improved more than 10%, and six improved to a rate greater than 55%, a level that corresponds to substantial protection against outbreaks. Staff education was essential but insufficient. Direct encouragement and dramatic informative endeavors helped, as did financial incentives, competitions, and requiring unambiguously worded consents for refusals. Paying staff members $150 each achieved improvement rapidly.

CONCLUSION: Quality improvement increased staff immunization rates at LTCFs, which reduces the risk of an influenza outbreak. Based on the insights learned about effective changes, the project developed a change package for use by other LTCFs.
Incidence of In‐Hospital Falls in Geriatric Patients Before and After the Introduction of an Interdisciplinary Team–Based Fall‐Prevention Intervention
Authors: Von Renteln‐Kruse Wolfgang , Krause Tom
Published: October 2007

Falls are among the most common unwanted events in older hospital inpatients, but evidence of effective prevention is still limited compared with that in the community and in long‐term care facilities. This article describes a prevention program and its effects on the incidence of falls in geriatric hospital wards. It was a prospective cohort study with historical control including all 4,272 patients (mean age 80, 69% female) before and 2,982 (mean age 81, 69% female) after introduction of the intervention. The intervention included fall‐risk assessment on admission and reassessment after a fall; risk alert; additional supervision and assistance with the patients' transfer and use of the toilet; provision of an information leaflet; individual patient and caregiver counseling; encouragement of appropriate use of eyeglasses, hearing aids, footwear, and mobility devices; and staff education. Measurements included standardized fall‐incidence reporting, activity of daily living and mobility status, number of falls and injurious falls, and number of patients who fell. Before the intervention was introduced, 893 falls were recorded. After the intervention was implemented, only 468 falls were recorded (incidence rate ratio (IRR)=0.82, 95% confidence interval (CI)=0.73–0.92), 240 versus 129 total injurious falls (IRR=0.84, 95% CI=0.67–1.04), 10 versus nine falls with fracture (IRR=1.40, 95% CI=0.51–3.85) and 611 versus 330 fallers. The relative risk of falling was significantly reduced (0.77, 95% CI=0.68–0.88). A structured multifactorial intervention reduced the incidence of falls, but not injurious falls, in a hospital ward setting with existing geriatric multidisciplinary care. Improvement of functional competence and mobility may be relevant to fall prevention in older hospital inpatients.
Academic Career Development in Geriatric Fellowship Training
Authors: Medina‐Walpole Annette , Fonzi Judith , Katz Paul R.
Published: October 2007

Career development is rarely formalized in the curricula of geriatric fellowship programs, and the training of new generations of academic leaders is challenging in the 1 year of fellowship training. To effectively prepare fellows for academic leadership, the University of Rochester's Division of Geriatrics, in collaboration with the Warner School of Graduate Education, created a yearlong course to achieve excellence in teaching and career development during the 1‐year geriatric fellowship. Nine interdisciplinary geriatric medicine, dentistry, and psychiatry fellows completed the course in its initial year (2005/06). As participants, fellows gained the knowledge and experience to successfully develop and implement educational initiatives in various formats. Fellows acquired teaching and leadership skills necessary to succeed as clinician–educators in an academic setting and to communicate effectively with patients, families, and colleagues. Fellows completed a series of individual and group education projects, including academic portfolio development, curriculum vitae revision, abstract submission and poster presentation at national meetings, lay lecture series development, and geriatric grand rounds presentation. One hundred percent of fellows reported that the course positively affected their career development, with six of nine fellows choosing academic careers. The course provided opportunities to teach and assess all six of the Accreditation Council of Graduate Medical Education core competencies. This academic career development course was intended to prepare geriatric fellows as the next generation of academic leaders as clinician–teacher–scholars. It could set a new standard for academic development during fellowship training and provide a model for national dissemination in other geriatric and subspecialty fellowship programs.
Physical Activity in Middle‐Aged Adults Reduces Risks of Functional Impairment Independent of Its Effect on Weight
Authors: Lang Iain A. , Guralnik Jack M. , Melzer David
Published: October 2007

OBJECTIVES: To assess the association between physical activity and subsequent physical functioning in middle‐aged adults across a range of body mass index (BMI) categories.

DESIGN: Prospective nationally representative cohort studies.

SETTING: The United States and England.

PARTICIPANTS: Eight thousand seven hundred two individuals in the United States and 1,507 in England aged 50 to 69 and free of impairment at baseline, followed up for 6 years.

MEASUREMENTS: Self‐reported and measured BMI and self‐reported level of physical activity. Outcome measures were score on a physical performance battery and self‐reported mobility impairment.

RESULTS: In both studies, being overweight and being obese were associated with greater risk of impairment (than being of recommended weight). In all weight categories and both countries, higher levels of physical activity were associated with lower risks of mobility impairment. For example, U.S. respondents of recommended weight (BMI 20–25) who were active on 3 or more days per week had a relative risk (RR) of incident mobility difficulties, compared with those who were less active, of 0.56 (95% confidence interval (CI)=0.40–0.78); for those who were obese (BMI ≥30) the corresponding RR was 0.59 (95% CI=0.45–0.76).

CONCLUSION: Excess bodyweight is a risk factor for impaired physical function in middle‐aged and older people. Physical activity is protective of impaired physical functioning in this age group in subjects with recommended weight, overweight, and obesity. Older adults should be encouraged to engage in appropriate levels of physical activity irrespective of their weight.
Pilot Test of an Attribution Retraining Intervention to Raise Walking Levels in Sedentary Older Adults
Authors: Sarkisian Catherine A. , Prohaska Thomas R. , Davis Connie , Weiner Bernard
Published: October 2007

OBJECTIVES: To pilot test a new behavioral intervention to increase walking in sedentary older adults.

DESIGN: Pre–post community‐based pilot study.

SETTING: Three senior centers in greater Los Angeles.

PARTICIPANTS: Forty‐six sedentary adults aged 65 and older.

INTERVENTION: At four weekly 1‐hour group sessions held at the senior centers, a trained health educator applied a theoretically grounded, standardized “attribution retraining” curriculum developed by a multidisciplinary team of investigators. Participants were taught that becoming sedentary is not inevitable with aging and that older adults should attribute being sedentary to modifiable attributes rather than to old age. A 1‐hour exercise class including strength, endurance, and flexibility training followed each weekly attribution retraining session.

MEASUREMENTS: Change from baseline in steps per week recorded using a digital pedometer was measured after 7 weeks. Age expectations (measured using the Expectations Regarding Aging‐38 survey, a previously tested instrument on which higher scores indicate that the participant expects high functioning with aging and lower scores indicate that the participant expects physical and mental decline) and health‐related quality of life were measured using in‐person interviews.

RESULTS: Mean steps per week increased from 24,749 to 30,707, a 24% increase—equivalent to 2.5 miles (2‐sided t‐test P=.002). Age expectation scores increased 30% (P<.001), and the changes in age expectations and steps per week correlated (correlation coefficient=0.39, P=.01). Participants experienced improved mental health–related quality of life (P=.049) and reported less difficulty with activities of daily living (P=.04). More than 50% of participants reported improvements in pain, energy level, and sleep quality.

CONCLUSION: In this small pre–post community‐based pilot study, a structured attribution retraining curriculum accompanied by a weekly exercise class was associated with increased walking levels and improved quality of life in sedentary older adults. Attribution retraining deserves further investigation as a potential means of increasing physical activity in sedentary older adults.
Functional Impact of Relative Versus Absolute Sarcopenia in Healthy Older Women
Authors: Estrada Marcos , Kleppinger Alison , Judge James O. , Walsh Stephen J. , Kuchel George A.
Published: October 2007

OBJECTIVES: To determine whether adjustment of muscle mass for height2 or for body mass represents a more‐relevant predictor of physical performance.

DESIGN: Cross‐sectional study, using baseline data from a trial comparing upper‐ and lower‐body training.

SETTING: Women recruited from the community and gynecological practices in Connecticut.

PARTICIPANTS: One hundred eighty‐nine healthy older (aged 67.5 ± 4.8), active women receiving estrogen for osteoporosis over 2 years.

MEASUREMENTS: Total and appendicular skeletal muscle (ASM) and fat mass (AFM) were determined using dual x‐ray absorptiometry. Physical performance, muscle strength, and fitness measures were obtained at baseline.

RESULTS: Adjusting ASM for height2 identifies lean women who are sarcopenic according to published standards yet fails to identify overweight and obese women whose ASM adjusted for body mass is low. ASM divided by body mass (ASM/body mass) is a stronger physical performance predictor, explaining 32.5%, 13.5%, 11.6%, 6.3%, and 6.8% of the variance in maximum time on treadmill, 6‐minute walk, gait speed, 8‐foot walk, and single leg stance, respectively, whereas ASM divided by height in m2 (ASM/height2) explained only 2.9%, 0.2%, 2.0%, 0.04%, and 0.1%. Multivariate modeling demonstrated considerable overlap in aspects of ASM/body mass and AFM/body mass associated with performance, with ASM/body mass dominant. In contrast, ASM/height2 is a much stronger predictor of leg press 1 repetition maximum and maximum power.

CONCLUSION: The results suggest that relative sarcopenia with ASM adjusted for body mass is a better mobility predictor, with absolute sarcopenia a better indicator of isolated muscle group function in healthy postmenopausal women receiving estrogen replacement.
Hypodermoclysis to Treat Dehydration: A Review of the Evidence
Authors: Remington Ruth , Hultman Todd
Published: October 2007

Dehydration is a serious acute condition in older adults associated with significant morbidity and mortality. Hypodermoclysis (HDC; the infusion of fluids into the subcutaneous tissue) can provide an alternative to intravenous (IV) rehydration of older adults.

This article reviews the relevant literature on the use of HDC to treat mild to moderate dehydration in older adults. A comprehensive search of the literature was conducted to identify research reports on the use of HDC to treat dehydration in older adults. Articles published in English during the previous 10 years were reviewed to reflect current standards of practice. One systematic review; two randomized, controlled trials; and six cohort studies were identified and appraised. Only one study was conducted in the United States; the remainder were conducted in Europe, Asia, and Canada. The evidence indicated that HDC is as effective as IV rehydration of older adults with mild to moderate dehydration. The literature cites advantages of HDC over IV hydration, including the same number of or fewer complications, cost savings, greater patient comfort, and less nursing time to start and maintain the infusion. It remains unclear from the literature why HDC is used infrequently in the United States.
Chewing Problems and Mortality in Older Adults in Home Care: Results from the Aged in Home Care Study
Authors: Onder Graziano , Liperoti Rosa , Soldato Manuel , Cipriani Maria Camilla , Bernabei Roberto , Landi Francesco
Published: October 2007

OBJECTIVES: To assess the association between chewing problems and risk of mortality in an older population receiving home care in Europe.

DESIGN: Retrospective cohort study.

SETTING: Eleven European countries.

PARTICIPANTS: Two thousand seven hundred fifty‐five older adults (mean age±standard deviation 82.2±7.2) in home care.

MEASUREMENTS: Data were collected using the Minimum Data Set for Home Care. Study personnel recorded chewing problems (inability to chew food easily and without pain or difficulties, regardless of cause) that presented in the last 3 days before baseline assessment. Data on mortality were collected over a 1‐year period.

RESULTS: Three hundred ninety‐five participants (14.3%) presented with chewing problems. One‐year mortality differed significantly according to presence of chewing problems; 303 of 2,361 (12.8%) without chewing problems (crude incident rate per person‐year (p‐y)=0.15) and 80 of 394 (20.3%) participants with chewing problems (crude incident rate per p‐y=0.24) died during follow‐up. After adjusting for potential confounders, the risk of death was significantly higher for participants with chewing problems (adjusted hazard ratio (HR)=1.45, 95% confidence intervals (CI)=1.05–1.99). This association remained after exclusion of participants with cognitive impairment (adjusted HR=1.50, 95% CI=1.03–2.20) and those with unintended weight loss (adjusted HR=1.62, 95% CI=1.12–2.34).

CONCLUSION: In older adults in home care in Europe, chewing problems are associated with greater risk of mortality.
Coronary Artery Calcification and Total Mortality in Elderly Men
Authors: Abbott Robert D. , Ueshima Hirotsugu , Masaki Kamal H. , Willcox Bradley J. , Rodriguez Beatriz L. , Ikeda Alvin , Yano Katsuhiko , White Lon R. , Curb J. David
Published: October 2007

OBJECTIVES:To examine the relationship between coronary artery calcification (CAC) and mortality in a sample of elderly men.

DESIGN:Prospective cohort study.

SETTING:The Honolulu Heart Program.

PARTICIPANTS:A population‐based sample of 224 men aged 84 to 96 with good cognitive function.

METHODS:From 2004 to 2005, subjects received physical examinations including CAC determinations. Participants were followed for up to 3 years for all‐cause mortality.

RESULTS:In the course of follow‐up, there were 17 deaths (28.0/1,000 person‐years). Risk of death rose consistently and significantly as CAC scores increased (P=.001). For CAC scores less than 10, no deaths were observed. For scores of 10 or higher, risk of death rose from 13.2 per 1,000 person‐years for CAC scores of 10 to 100 to 48.6 per 1,000 person‐years for CAC scores greater than 1,000. Findings persisted after adjusting for age and traditional risk factors. In this sample of elderly men, CAC was the only factor with a significant relationship with total mortality.

CONCLUSION:Higher CAC scores in elderly men are associated with greater risk of death. Screening for CAC could be important for developing strategies to improve longevity in elderly people, particularly at an age when associations between mortality and traditional risk factors are weak.
Color Stability of Glazed and Polished Dental Porcelains
Authors: Yılmaz Caner , Korkmaz Turan , Demirköprülü Hişam , Ergün Gülfem , Özkan Yalçın
Published: October 2007

Purpose: The purpose of this study was to compare the visual and colorimetric color stability of two ultra low‐fusing and three conventional low‐fusing porcelains on both glazed and polished surfaces.

Materials and Methods: Twelve disks, 10 mm in diameter and 3 mm in thickness, were fabricated for each porcelain. Specimens were glazed using their specific glaze materials. For each type of porcelain, the specimens were divided into two groups: one group was immersed in methylene blue and the other group in distilled water as a control. The surfaces were visually examined for staining without magnification. Objective color measurement was performed for each sample using a Tristimulus colorimeter. After examining the color of the glazed specimens, glazed layers were removed from the surface of the specimens to simulate an intraoral environment. Then, porcelain polishing points and diamond polishing paste were applied. The samples were immersed again in methylene blue and distilled water, and after removing from the staining solution and distilled water, visual and objective measurements were performed again.

Results: Visually discernible stain was present on the polished groups of all five porcelains immersed in methylene blue, whereas the glazed group immersed in methylene blue showed no staining. No staining was observed with glazed and polished samples immersed in distilled water. The objective evaluation showed that the polished porcelain surface of all five porcelain products had statistically significant color deviation than the glazed surface in the same group after immersion in methylene blue. The results of this study show a statistically significant difference in color stability between the polished and glazed specimens.

Conclusion: It may be concluded that the glazed specimens showed a better color stability, although the staining observed in the polished specimens was not clinically noticeable.
Marginal Adaptation and Color Stability of Four Provisional Materials
Authors: Givens Edward J. , Neiva Gisele , Yaman Peter , Dennison Joseph B.
Published: October 2007

Purpose: A number of provisional restorative materials exist on the market. This study tested marginal fit and color stability of three provisional restorative materials and a control.

Materials and Methods: Two auto‐cure materials, Protemp Garant and Integrity, and one dual‐cure material, Luxatemp Solar, were tested against SNAP, a polyethyl methacrylate control. A maxillary right central incisor ivorine tooth was prepared for a full coverage all‐ceramic crown, with a 1.5‐mm chamfer margin. Four points were engraved at a point 1 mm below the facial, lingual, mesial, and distal margins, and replicas (n = 40) were produced by the manufacturer. Provisional crowns (n = 10 × 4) were fabricated on the individual replicas using a polyethylene coping template. The crowns were trimmed under magnification using an acrylic bur. The distance from the crown margins to a point tangent to the engraved markings was measured under 10× magnification and recorded. For color stability, 10‐mm diameter × 2‐mm thick discs (n = 10 × 4) were fabricated and immersed cyclically in tea for 1 week in a Tucillo/Nielson apparatus. Color measurements were recorded for each specimen at baseline and after staining. ΔE values were calculated to determine the extent of the color change.

Results: The means of the four marginal discrepancy measurements for each specimen were analyzed using a 1‐way ANOVA and Tukey post‐hoc comparison. Luxatemp Solar had statistically significant marginal discrepancy (319 μm, p < 0.05) when compared to the other provisional materials. A significant color change (ΔE = 4.33, p < 0.05) was found for Protemp Garant.

Conclusion: The dual‐cure temporary material (Luxatemp Solar) exhibited significantly more discrepancy at the margin than the auto‐cure bis‐acryl materials or acrylic control. Protemp Garant exhibited a clinically noticeable change in shade after 1 week in staining solution, whereas the other materials did not exhibit a clinically noticeable change.

Clinical Implications: Provisional crowns fabricated from SNAP, Protemp Garant, and Integrity exhibited similarly low marginal discrepancy. SNAP, Luxatemp Solar, and Integrity did not demonstrate a clinically detectable change in shade after 1 week in a staining solution.
Intrapulpal Heat Generation during Provisionalization: Effect of Desensitizer and Matrix Type
Authors: Akova Tolga , Ozkomur Ahmet , Dundar Cengiz , Aytutuldu Neslin
Published: October 2007

Purpose: This study investigated the effect of different matrices and application of a desensitizer on pulpal temperature rise during direct provisionalization.

Materials and Methods: The apical third of a second premolar was resected and pulpal tissue was removed. Silicone heat‐conducting medium was injected, and a J‐type thermocouple was inserted into the pulp chamber and sealed. The tooth was embedded in acrylic resin with its cervical line 1 mm higher than the base. Addition and condensation silicone impression materials were mixed and placed inside plastic molds. Impressions were taken before tooth preparation. The tooth was then prepared with a 1.5‐mm shoulder finish line. The experimental model was kept in a 36 °C water bath. Four provisional materials were applied in sequence onto the prepared tooth using matrices. Each provisional resin was used in combination with each matrix (n = 12). Then a dentin desensitizer was coated on the prepared tooth and provisionalizations were made in the same manner. The thermocouple was connected to the data‐logger. During setting of the resins, pulp temperatures were recorded and transferred to the computer. Measurements were conducted for each test group by calculating the temperature rise as the difference between the start and highest temperature reading.

Results: The type of the silicone matrix used and the use of desensitizer did not affect the intrapulpal heat generation during direct provisionalization.

Conclusion: Application of a desensitizer and different type of matrix seems to be noneffective on intrapulpal heat rise, although the type of provisional material used may be effective.
Fracture Resistance and Stress Distribution in Endodontically Treated Maxillary Premolars Restored with Composite Resin
Authors: Soares Paulo Vinícius , Santos‐Filho Paulo César Freitas , Queiroz Ellyne Cavalcanti , Araújo Thiago Caixeta , Campos Roberto Elias , Araújo Cleudmar Amaral , Soares Carlos José
Published: October 2007

Purpose: The aim of this study was to evaluate the effect of endodontic and restorative treatment on the fracture resistance of posterior teeth.

Materials and Methods: Fifty intact premolars were selected and randomly placed into five groups (n = 10): G1, intact teeth (control); G2, mesial‐occlusal‐distal (MOD) preparation; G3, MOD preparation restored with composite resin (Z‐250, 3M ESPE); G4, MOD preparation and endodontic treatment; and G5, MOD preparation, endodontic treatment, and composite resin restoration. The specimens were submitted to an axial compression load in a mechanical test machine (EMIC), at a speed of 0.5 mm/min. Fracture patterns were analyzed at four levels. Five 2D numerical models were created by Ansys 10.0 for finite element analysis (FEA).

Results: Mean values of compressive strength for all groups were (Kgf): G1 (83.6 ± 25.4); G2 (52.7 ± 20.2); G3 (82.1 ± 24.9); G4 (40.2 ± 14.2); G5 (64.5 ± 18.1). Statistical analysis (ANOVA and Tukey's test) showed that fracture resistance of G1 was significantly higher than that of G5, G2, and G4. Resistance of G3 was also higher than that of G2 and G4. Results showed that the tooth resistance is completely maintained when MOD preparation is restored with composite resin and partially recovered when MOD preparation associated with an endodontic access is restored in the same way. The endodontic treatment and composite resin restoration influenced stress distribution in the dental structure.

Conclusions: Composite resin restoration plays an important role in recovering tooth strength. With regard to fracture mode, restoration and endodontic treatment increased the incidence of periodontal involvement, which was demonstrated by association with the finite element mechanical test method.
Accuracy of a Fixed Value Nasion Relator in Facebow Design
Authors: Wilcox Charles W. , Sheets James L. , Wilwerding Terry M.
Published: October 2007

Purpose: This study examined whether a fixed value nasion relator accurately locates the orbitale in a patient population.

Materials and Methods: The mean value for the vertical distance between soft tissue nasion and orbitale was determined through the analysis of cephalometric radiographs of 114 adult patients. This value was then compared to a facebow design, which uses a fixed value of 25.4 mm.

Results: In this study, the mean distance between the orbitale and nasion was found to be 26.8 mm. The values ranged from 15.9 to 39.4 mm with a standard deviation of 3.87 mm.

Conclusion: The difference between the calculated mean and the 25.4 mm fixed value was less than 2.0 mm and presumed to be clinically irrelevant; however, an accumulation of design errors combined with the variation within the patient population was asserted to be clinically relevant and makes the use of a fixed value nasion relator impractical.
Cement Selection for Cement‐Retained Crown Technique with Dental Implants
Authors: Sheets James L. , Wilcox Charles , Wilwerding Terry
Published: October 2007

Purpose: The purpose of this study was to assess and compare the retentive nature of common dental cements that have been adapted for use in the implant abutment cement‐retained crown (CRC) technique with those specifically formulated for this purpose.

Materials and Methods: Ten regular diameter implant analogs were embedded in stainless steel disks. Unmodified CRC abutments were attached and torqued to 30 Ncm. Test crowns were waxed and cast with base metal alloy. Castings were fitted, cleaned with aluminum oxide, and steam cleaned prior to application of the cement. The cements used were: (1) Temp Bond, (2) UltraTemp, regular, (3) UltraTemp firm, (4) ImProv with petroleum jelly coating of crown, (5) ImProv without petroleum jelly, (6) Premier Implant with KY Jelly coating of abutment, (7) Premier Implant without KY jelly, (8) TR‐2, (9) Fleck's, (10) Ketac Cem Aplicap, and (11) Fuji Plus Capsule. After cementation, assemblies were stored for 24 hours. Each sample was subjected to a pull‐out test using an Instron universal testing machine at a crosshead speed of 5.0 mm/min. Loads required to remove the crowns were recorded, and mean values for each group determined. A one‐way ANOVA and a post hoc least square difference (LSD) test were done for pairwise comparison at a confidence interval of 95%.

Results: The mean values (±SD) of loads at failure (n = 10) for various cements were as follows (N): Ultratemp, regular 358.6 (±38.2) (Group A), ImProv without petroleum jelly 172.4 (±59.6) (Group B), Fleck's 171.8 (±62.2) (Group B), Ketac Cem 167.8 (±69.1) (Group B), UltraTemp firm 158.8 (±62.7) (Group BC), Fuji Plus 147.5 (±69.7) (Group BC), Premier without KY jelly 131.6 (±31.8) (Group BC), ImProv using petroleum jelly 130.8 (±42.5) (Group BC), Temp Bond 117.8 (±48.3) (Group C), TR‐2 41.2 (±16.6) (Group D), and Premier with KY jelly 31.6 (±24.8) (Group D). Groups with the same letter were not significantly different.

Conclusions: Within the limitations of this in vitro study, it is not suggested that any one cement is better than another at retaining cement‐retained crowns (CRCs) to implant abutments or that a threshold value must be accomplished to ensure retention. The ranking of cements presented is meant to be a discretionary guide for the clinician in deciding the amount of desired retention between castings and implant abutments.
Effect of Auxiliary Grooves on Molar Crown Preparations Lacking Resistance Form: A Laboratory Study
Authors: Lu Po‐Ching , Wilson Peter
Published: October 2007

Purpose: To investigate the effect of auxiliary grooves on resistance to dislodgment of crowns on compromised molar preparations lacking resistance form.

Materials and Methods: Thirty human molar teeth were randomly assigned to three groups of ten, and prepared to a height‐to‐width ratio of 0.3 with a total convergence of 50°, and 1‐mm shoulder margin. Base metal alloy copings were constructed with a 45° loading platform and cemented with zinc phosphate cement under a 50 N load. Initially, resistance testing was conducted using a Universal Testing Machine (Instron) at 1 mm/min for all 30 specimens. Following crown dislodgment, Group 1 copings were recemented and retested, Group 2 had one axial groove added, and Group 3 had two axial grooves added. New copings for Groups 2 and 3 were made, cemented, and again tested for resistance. Standardized radiographs were taken prior to initial cementation and scanned into digital images. The percentage of area occupied by the pulpal chamber above the acrylic mounting (PS), and the closest distance to pulp from the preparation surface (CD) were measured.

Results: Recementation or the addition of one groove did not affect the dislodgment values (p > 0.05), but addition of two grooves caused a highly significant increase in resistance (p < 0.001). Regression analysis showed an inverse relationship between initial resistance values and pulpal space area. Lower resistance values were observed when the pulpal space area was large (p= 0.004).

Conclusions: Crowns can be recemented without affecting resistance to dislodgment. Two grooves should be incorporated into compromised molar crown preparations to increase resistance form. Teeth with large pulps and therefore less coronal dentine have poorer resistance form, and therefore would benefit from placement of auxiliary grooves.
Individually Prefabricated Prosthesis for Maxilla Reconstruction
Authors: Singare Sekou , Liu Yaxiong , Li Dichen , Lu Bingheng , He Sanhu
Published: October 2007

The reconstruction of maxillofacial bone defects by the intraoperative modeling of implants may reduce the predictability of the esthetic result, leading to more invasive surgery and increased surgical time. To improve the maxillofacial surgery outcome, modern manufacturing methods such as rapid prototyping (RP) technology and methods based on reverse engineering (RE) and medical imaging data are applicable to the manufacture of custom‐made maxillary prostheses. After acquisition of data, an individual computer‐based 3D model of the bony defect is generated. These data are transferred into RE software to create the prosthesis using a computer‐aided design (CAD) model, which is directed into the RP machine for the production of the physical model. The precise fit of the prosthesis is evaluated using the prosthesis and skull models. The prosthesis is then directly used in investment casting such as “Quick Cast” pattern to produce the titanium model. In the clinical reports presented here, reconstructions of two patients with large maxillary bone defects were performed using this new method. The custom prostheses perfectly fit the defects during the operations, and surgery time was reduced. These cases show that the prefabrication of a prosthesis using modern manufacturing technology is an effective method for maxillofacial defect reconstruction.
Importance of Intensive Lipid Lowering in Acute Coronary Syndrome and Percutaneous Coronary Intervention
Authors: KUMAR AMIT , CANNON CHRISTOPHER P.
Published: October 2007

Lipid‐lowering therapy with statins reduces the risk of cardiovascular events in patients with established coronary heart disease (CHD). Traditionally, statins were perceived to lower the long‐term cardiovascular risk by reducing elevated low‐density lipoprotein cholesterol (LCL‐C). Recently, this benefit has been established for patients early after acute coronary syndrome (ACS). The benefit appears linked to reductions in both LDL‐C and C‐reactive protein (CRP) that is a marker of systemic inflammation. This paper will review the current state of evidence from key recent statin trials in ACS and percutaneous coronary intervention (PCI) and discuss their significance for clinical practice.
Successful Treatment of Trifurcation and Quadrifurcation Lesions Using a Minimal Protrusion Balloon Crush Technique
Authors: ALIZADEHRANJBAR KEYSUN , BRASS NEIL , CHEUNG POKEE , LEUNG RAYMOND , CHAN MICHAEL , HUI WILLIAM
Published: October 2007

Percutaneous treatment of coronary bifurcation lesions remains a challenging aspect of interventional cardiology, but the approach to trifurcation and quadrifurcation lesions can be considered “double jeopardy.” We describe two cases of trifurcation and one case of quadrifurcation that were treated percutaneously using a “minimal protrusion balloon crush technique.” Immediate and long‐term results were favorable with this approach.
IgG4 autoantibodies induce dermal–epidermal separation
Authors: Mihai Sidonia , Chiriac Mircea T. , Herrero‐González Josep E. , Goodall Margaret , Jefferis Roy , Savage Caroline O. S. , Zillikens Detlef , Sitaru Cassian
Published: October 2007

Bullous pemphigoid (BP) is a sub‐epidermal autoimmune blistering disease associated with autoantibodies to the dermal–epidermal junction (DEJ). Patients’ autoantibodies induce dermal–epidermal separation when co‐incubated with cryosections of human skin and leucocytes from healthy volunteers. IgG autoantibodies trigger complement and/or leucocyte activation resulting in specific pathology in several autoimmune conditions. In these diseases, IgG1 and IgG3 isotypes, but not the IgG4 subclass, are thought to trigger inflammatory pathways resulting in tissue damage. The capacity of IgG4 autoantibodies to mediate tissue damage has not yet been demonstrated. In this study, we isolated IgG1 and IgG4 autoantibodies from bullous pemhigoid patients'serum and analysed their blister‐inducing potential in our cryosection assay. As expected, complement‐fixing IgG1 autoantibodies induced sub‐epidermal splits in this experimental model. Purified IgG4 did not fix complement, but, interestingly, like IgG1, activated leucocytes and induced dermal–epidermal separation. The potential of IgG4 autoantibodies to induce Fc‐dependent dermal–epidermal separation was significantly lower compared to IgG1. Our results demonstrate that IgG4 autoantibodies are able to activate leucocytes and point to a hitherto less recognized function of IgG4. Moreover, for the first time, we clearly demonstrate that BP IgG4 autoantibodies have the capacity to induce leucocyte‐dependent tissue damage.
Recent advances in cancer stem/progenitor cell research: therapeutic implications for overcoming resistance to the most aggressive cancers
Authors: Mimeault M. , Hauke R. , Mehta P. P. , Batra S. K.
Published: October 2007

Introduction

Functions of cancer progenitor cells in the cancer initiation and progression

New model of carcinogenesis based on the cancer progenitor cells

Isolation and ex vitro and in vivo characterization of functional properties of cancer progenitor cells

Functions of cancer progenitor cells in the cancer development

Influence of local tumour microenvironment on the behavior of cancer progenitor cells

Cancer types originating from cancer progenitor cells

New concepts of the heterogeneity of cancers derived from distinct cancer progenitor cells

Implication of cancer progenitor cells in bone marrow‐derived cancers

Leukaemias

Sarcomas

Implication of cancer progenitor cells in pediatric and adult brain tumors

Implication of cancer progenitor cells in other cancer types

Novel cancer therapies by molecular targeting of cancer progenitor cells and their microenvironment

New concepts on the functions of cancer progenitor cells in the resistance to current cancer therapies

New combination therapies against the aggressive and recurrent cancers

Targeting cancer progenitor cells

Targeting the local microenvironment of cancer progenitor cells

Conclusions

Future directions and perspectives

Overcoming intrinsic and acquired resistance of cancer stem/progenitor cells to current clinical treatments represents a major challenge in treating and curing the most aggressive and metastatic cancers. This review summarizes recent advances in our understanding of the cellular origin and molecular mechanisms at the basis of cancer initiation and progression as well as the heterogeneity of cancers arising from the malignant transformation of adult stem/progenitor cells. We describe the critical functions provided by several growth factor cascades, including epidermal growth factor receptor (EGFR), platelet‐derived growth factor receptor (PDGFR), stem cell factor (SCF) receptor (KIT), hedgehog and Wnt/β ‐catenin signalling pathways that are frequently activated in cancer progenitor cells and are involved in their sustained growth, survival, invasion and drug resistance. Of therapeutic interest, we also discuss recent progress in the development of new drug combinations to treat the highly aggressive and metastatic cancers including refractory/relapsed leukaemias, melanoma and head and neck, brain, lung, breast, ovary, prostate, pancreas and gastrointestinal cancers which remain incurable in the clinics. The emphasis is on new therapeutic strategies consisting of molecular targeting of distinct oncogenic signalling elements activated in the cancer progenitor cells and their local microenvironment during cancer progression. These new targeted therapies should improve the efficacy of current therapeutic treatments against aggressive cancers, and thereby preventing disease relapse and enhancing patient survival.
Curcumin modulation of IFN‐β and IL‐12 signalling and cytokine induction in human T cells
Authors: Fahey Angela J. , Adrian Robins R. , Constantinescu Cris S.
Published: October 2007

Curcumin is a polyphenol derived from the dietary spice turmeric. It possesses diverse anti‐inflammatory and anti‐cancer properties. Curcumin has been shown to exhibit an inhibitory effect on the production of inflammatory cytokines by human monocytes and has inhibited the animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE) in association with a decrease in interleukin 12 (IL‐12) production and signal transducer and activator of transcription 4 (STAT4) activation. The type I interferon (IFN) IFN‐has the ability to suppress IL‐12. Both IL‐12 and IFN‐α/β signal through the activation by phosphorylation of STAT4. Our aim was to investigate the effects of curcumin on the ability of T cells to respond to IL‐12 or IFN‐α/β. We report that curcumin decreases IL‐12‐induced STAT4 phosphorylation, IFN‐γ production, and IL‐12 Rβ1 and β2 expression. IFN‐β‐induced STAT4 phosphorylation, IL‐10 production and IFN receptor (IFNAR) subunits 1 and 2 expression were enhanced by curcumin. Curcumin increased IFN‐α‐induced IL‐10 and IFNAR1 expression. Prior exposure to curcumin decreased IFN‐α‐induced IFNAR2 expression and did not modify the level of IFN‐α‐induced pSTAT4 generation. Thus, the effect of curcumin on STAT4 activation in T cells is dependent upon the stimulus to which the T cells have been exposed.
Structure and function of the human calcium‐sensing receptor: insights from natural and engineered mutations and allosteric modulators
Authors: Hu Jianxin , Spiegel Allen M.
Published: October 2007

Introduction

The CaR is a unique family 3 GPCR

Architecture of the CaR

Naturally occurring inactivating mutations associated with FHH and NSHPT

Naturally occurring activating mutations associated with ADH and Bartter's syndrome type V

Allosteric modulators of the CaR and their therapeutic potentials

Concluding remarks

The human extracellular Ca2+‐sensing receptor (CaR), a member of the G protein‐coupled receptor family 3, plays a key role in the regulation of extracellular calcium homeostasis. It is one of just a few G protein‐coupled receptors with a large number of naturally occurring mutations identified in patients. In contrast to the small sizes of its agonists, this large dimeric receptor consists of domains with topologically distinctive orthos‐teric and allosteric sites. Information derived from studies of naturally occurring mutations, engineered mutations, allosteric modulators and crystal structures of the agonist‐binding domain of homologous type 1 metabotropic glutamate receptor and G protein‐coupled rhodopsin offers new insights into the structure and function of the CaR.
DLC‐1:a Rho GTPase‐activating protein and tumour suppressor
Authors: Durkin Marian E. , Yuan Bao‐Zhu , Zhou Xiaoling , Zimonjic Drazen B. , Lowy Douglas R. , Thorgeirsson Snorri S. , Popescu Nicholas C.
Published: October 2007

Introduction

Expression of DLC family proteins

Features of DLC family protein domains

Biological functions of DLC‐1

Genetic analysis of DLC‐1 function

The DLC family proteins in cancer

Conclusions and future directions

The deleted in liver cancer 1 (DLC‐1) gene encodes a GTPase activating protein that acts as a negative regulator of the Rho family of small GTPases. Rho proteins transduce signals that influence cell morphology and physiology, and their aberrant up‐regulation is a key factor in the neoplastic process, including metastasis. Since its discovery, compelling evidence has accumulated that demonstrates a role for DLC‐1 as a bona fide tumour suppressor gene in different types of human cancer. Loss of DLC‐1 expression mediated by genetic and epigenetic mechanisms has been associated with the development of many human cancers, and restoration of DLC‐1 expression inhibited the growth of tumour cells in vivo and in vitro. Two closely related genes, DLC‐2 and DLC‐3, may also be tumour suppressors. This review presents the current status of progress in understanding the biological functions of DLC‐1 and its relatives and their roles in neoplasia.
Tissue engineering of blood vessel
Authors: Zhang Wen Jie , Liu Wei , Cui Lei , Cao Yilin
Published: October 2007

Introduction

Components of blood vessel

Principle of vessel engineering

Seeding cells sources

Biodegradable scaffolds

Vessel engineering in vitro

Clinical applications

Future perspectives

Vascular grafts are in large demand for coronary and peripheral bypass surgeries. Although synthetic grafts have been developed, replacement of vessels with purely synthetic polymeric conduits often leads to the failure of such graft, especially in the grafts less than 6 mm in diameter or in the areas of low blood flow, mainly due to the early formation of thrombosis. Moreover, the commonly used materials lack growth potential, and long‐term results have revealed several material‐related failures, such as stenosis, thromboembolization, calcium deposition and infection. Tissue engineering has become a promising approach for generating a bio‐compatible vessel graft with growth potential. Since the first success of constructing blood vessels with collagen and cultured vascular cells by Weinberg and Bell, there has been considerable progress in the area of vessel engineering. To date, tissue‐ engineered blood vessels (TEBVs) could be successfully constructed in vitro, and be used to repair the vascular defects in animal models. This review describes the major progress in the field, including the seeding cell sources, the biodegradable scaffolds, the construction technologies, as well as the encouraging achievements in clinical applications. The remaining challenges are also discussed.
Calcium‐associated mechanisms in gut pacemaker activity
Authors: Nakayama Shinsuke , Kajioka Shunichi , Goto Kazunori , Takaki Miyako , Liu Hong‐Nian
Published: October 2007

Introduction

A considerable body of evidence has revealed that interstitial cells of Cajal (ICC), identified with c‐Kit‐immunoreactivity, act as gut pacemaker cells, with spontaneous Ca2+ activity in ICC as the probable primary mechanism. Namely, intracellular (cytosolic) Ca2+ oscillations in ICC periodically activate plasmalemmal Ca2+‐dependent ion channels and thereby generate pacemaker potentials. This review will, thus, focus on Ca2+‐associated mechanisms in ICC in the gastrointestinal (GI) tract, including auxiliary organs.
Integrin regulation of caveolin function
Authors: Salanueva Iñigo J. , Cerezo Ana , Guadamillas Marta C. , Del Pozo Miguel A.
Published: October 2007

Introduction

Caveolae mediate signalling through direct and indirect mechanisms

Signalling pathways at rafts: targeting by integrins

Integrin triggered CEMM internalization is mediated by caveolae

Dual role of caveolin Y14 phosphorylation: endocytosis vs. cell migration

Conclusions

Caveolae are unique organelles that are found in the plasma membrane of many cell types. They participate in various processes such as lipid recycling, cellular signalling and endocytosis. A variety of signalling molecules localize to caveolae in response to various stimuli, providing a potential mechanism for the spatial regulation of signal transduction pathways. Caveolin‐1, a constitutive protein of caveolae, has been implicated in the regulation of cell growth, lipid trafficking, endocytosis and cell migration. Phosphorylation of caveolin‐1 on Tyr 14 is involved in integrin‐regulated caveolae trafficking and also in signalling at focal adhesions in migrating cells. In this review, we focus on recent studies that describe the role of caveolin‐1 in integrin signal transduction, and how this interplay links extracellular matrix anchorage to cell proliferation, polarity and directional migration.
Matrix metalloproteinase‐2, caveolins, focal adhesion kinase and c‐Kit in cells of the mouse myocardium
Authors: Cho Woo Jung , Chow Ava K. , Schulz Richard , Daniel Edwin E.
Published: October 2007

Matrix metalloproteinase‐2 (MMP‐2) may play roles at intracellular and extracellular sites of the heart in ischaemia/reperfusion injury. Caveolins (Cav‐1, ‐2 and ‐3) are lipid raft proteins which play roles in cell sig‐nalling. This study examined, using immunohistochemistry and two photon confocal microscopy, if MMP‐2 and caveolins co‐localize at the plasma membrane of cardiac cells: cardiomyocytes (CM), fibroblasts (FB) and capillary endothelial cells (CEC) in the left ventricle (LV) of the Cav‐1+/+ and Cav‐1−/− mouse heart. In Cav‐1+/+ mouse LV MMP‐2 and Cav‐1 co‐localized at CM plasma membranes, and at multiple locations in FB and CEC. MMP‐2 co‐localized with Cav‐2 only at CEC. MMP‐2 co‐localized with Cav‐3 at CM plasma membranes and Z‐lines, and partially at FB and CEC. In Cav‐1−/− LV Cav‐1 and MMP‐2 were absent or reduced everywhere. Cav‐2 appeared at CEC despite the absence of Cav‐1. Cav‐3 appeared at CM plasma membranes and Z‐lines, FB and CEC. Also, FAK in FB and c‐Kit in interstitial Cajal‐like cells (ICLC) were completely absent. By transmission electron microscopy in Cav‐1+/+, regular size caveolae (Cav) were at CEC, irregular size Cav were at CM and a few were at FB. In Cav‐1−/− there were few Cav at CM and FB and some at CEC. To conclude, MMP‐2 is closely associated with caveolins at FB and CEC as well as at CM. Also, MMP‐2 is closely associated with FAK at FB and c‐Kit at ICLC. Thus, Cav‐1 expression is not necessary for Cav‐2 expression. Cav‐3 or Cav‐3 with Cav‐2 has the capability to make Cav.