bluuebunny/crossref_metadata_2025 huggingface dataset:
Cell-Permeable Pentapeptide V5 Inhibits Apoptosis and Enhances Insulin Secretion, Allowing Experimental Single-Donor Islet Transplantation in Mice
Authors: Rivas-Carrillo Jorge D. , Soto-Gutierrez Alejandro , Navarro-Alvarez Nalu , Noguchi Hirofumi , Okitsu Teru , Chen Yong , Yuasa Takeshi , Tanaka Kimiaki , Narushima Michiki , Miki Atsushi , Misawa Haruo , Tabata Yasuhiko , Jun Hee-Sook , Matsumoto Shinichi , Fox Ira J. , Tanaka Noriaki , Kobayashi Naoya
Published: April 2007

OBJECTIVE—Treatment of diabetic patients by pancreatic islet transplantation often requires the use of islets from two to four donors to produce insulin independence in a single recipient. Following isolation and transplantation, islets are susceptible to apoptosis, which limits their function and probably long-term islet graft survival.

RESEARCH DESIGN AND METHODS—To address this issue, we examined the effect of the cell-permeable apoptosis inhibitor pentapeptide Val-Pro-Met-Leu-Lys, V5, on pancreatic islets in a mouse model.

RESULTS—V5 treatment upregulated expression of anti-apoptotic proteins Bcl-2 and XIAP (X-linked inhibitor of apoptosis protein) by more than 3- and 11-fold and downregulated expression of apoptosis-inducing proteins Bax, Bad, and nuclear factor-κB–p65 by 10, 30, and nearly 50%, respectively. Treatment improved the recovered islet mass following collagenase digestion and isolation by 44% and in vitro glucose-responsive insulin secretion nearly fourfold. Following transplantation in streptozotocin-induced diabetic mice, 150 V5-treated islet equivalents functioned as well as 450 control untreated islet equivalents in normalizing blood glucose.

CONCLUSIONS—These studies indicate that inhibition of apoptosis by V5 significantly improves islet function following isolation and improves islet graft function following transplantation. Use of this reagent in clinical islet transplantation could have a dramatic impact on the number of patients that might benefit from this therapy and could affect long-term graft survival.
Carbon Nanotube Field‐Effect‐Transistor‐Based Biosensors
Authors: Allen B. L. , Kichambare P. D. , Star A.
Published: April 2007

There is an explosive interest in 1D nanostructured materials for biological sensors. Among these nanometer‐scale materials, single‐walled carbon nanotubes (SWNTs) offer the advantages of possible biocompatibility, size compatibility, and sensitivity towards minute electrical perturbations. In particular, because of these inherent qualities, changes in SWNT conductivity have been explored in order to study the interaction of biomolecules with SWNTs. This Review discusses these interactions, with a focus on carbon nanotube field‐effect transistors (NTFETs). Recent examples of applications of NTFET devices for detection of proteins, antibody–antigen assays, DNA hybridization, and enzymatic reactions involving glucose are summarized. Examples of complementary techniques, such as microscopy and spectroscopy, are covered as well.
Manipulation of crystal shape by cycles of growth and dissolution
Authors: Snyder Ryan C. , Studener Stephan , Doherty Michael F.
Published: April 2007

A method for the manipulation of crystal shape by using cycles of growth and dissolution is presented, representing a unique process‐based solution to an important product quality concern. Using 3‐D shape evolution models for faceted crystal growth and dissolution, results are reported for cycling both an illustrative crystal system, as well as a physical plate‐like system. The results show that crystal shape can be manipulated by cycling when the relative growth and dissolution rates are anisotropic, which can be caused by differences in growth mechanism, asymmetry in super/undersaturation, and by the use of surface active additives. Since this method of crystal shape enhancement uses the existing liquid solution, it could be a valuable alternative to the traditional methods which often require changes in the chemical nature of the solution, for example, by changing solvent. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Retention of the stationary phase for high‐speed countercurrent chromatography
Authors: He Chao‐Hong , Zhao Chun‐Xia
Published: April 2007

High‐speed countercurrent chromatography (HSCCC) is an emerging technique for preparative purification of a wide variety of solutes. Retention of the stationary phase is a crucial variable which is used for the derivation of the column efficiency, peak resolution, and solute retention. A mathematical model was proposed to describe the influences of operation conditions (flow rate, rotation speed), physical properties (density difference, viscosity, and interfacial tension), and instrument parameters (tube diameter, revolution radius) on the retention of the stationary phase, by building on the flow behavior of the two phases in the coiled column, laminar flow or droplet flow. The model parameters, together with the critical value at which the transition between the laminar flow and droplet flow occurs, were determined by the analysis of experimental data of the retention of the stationary phase measured in this work. Furthermore, the proposed model was used to predict the literature data of retention of the stationary phase for seven HSCCC apparatuses including preparative, semi‐preparative, and analytical types, with the coiled column material of PTFE and stainless steel, and for 16 two‐phase systems with 151 data points. The agreement between the predicted and the literature data is quite good with the total absolute deviation (AAD%) of 2.96% and the maximum deviation of 12.8%. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Application of L3 sponge phase in extraction of polycyclic aromatic hydrocarbons
Authors: Hung Kun‐Chih , Chen Bing‐Hung
Published: April 2007

Application of L3 sponge phase as an extractant in extraction of polycyclic aromatic hydrocarbons (PAHs) from aqueous solution were studied systematically at 25°C with three nonionic surfactants, Tergitol 15‐S‐5, LE‐203 (C12E3), and Brij 30 (C12E4). The transition temperatures of the coexisting W + L3 phases of these surfactants could be regulated with the addition of proper salting‐out electrolytes and short‐chain alcohols. The low viscosities of these L3‐phase extractants, ranging from 10 to 40 mPa s, make it not difficult for separation of these extract‐containing L3 phases from the coexisting water (W) phases. Compared to the conventional cloud‐point extraction techniques, a relatively larger preconcentration factor with satisfactory recovery efficiency of PAHs are achieved in such L3‐phase extraction procedure. For example, a preconcentration factor as much as ca. 200 was achieved in 0.2 wt % Tergitol 15‐S‐5 solution added with 5.6 wt % NaCl. In general, a higher preconcentration factor is attained with a decrease in surfactant concentration and/or with increasing concentrations of additives employed in this work. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Non‐verbal deficits in young children with a genetic metabolic disorder: WPPSI‐III performance in cystinosis
Authors: Spilkin Amy M. , Ballantyne Angela O. , Babchuck Lynne R. , Trauner Doris A.
Published: April 2007

Cystinosis is a recessive genetic metabolic disorder in which the amino acid cystine accumulates in various organs of the body. Previous studies have demonstrated visuospatial dysfunction in children and adults with this disorder. It is not known whether this is a result of the genetic alteration or an accumulation of cystine in the brain over time. This study investigated patterns of performance in 20 young children with cystinosis (4–7 years) and 20 matched controls on the Wechsler Preschool and Primary Scale of Intelligence‐Third Edition (WPPSI‐III). The children with cystinosis had a mean Full Scale IQ at the low end of the average range. Their overall cognitive functioning was comprised of average verbal abilities, low average non‐verbal abilities, and low average processing speed. Multivariate analyses indicated that the cystinosis and control groups were not significantly different on the verbal subtests. In contrast, the cystinosis group performed significantly more poorly than controls on the performance and processing speed subtests. Although overall intellectual function was in the normal range, young children with cystinosis demonstrated a discrepancy such that non‐verbal abilities were poorer relative to verbal abilities. This pattern resembles the cognitive profile found previously in older individuals with cystinosis and indicates that the specific cognitive profile emerges early in development. These findings suggest that the cognitive dysfunction in cystinosis is not merely the result of cystine accumulation over time but may be related to differences in brain development as a consequence of alterations or deletions of the cystinosin gene. © 2007 Wiley‐Liss, Inc.
A novel CDU model for refinery planning
Authors: Li Wenkai , Hui Chi‐Wai , Karimi I. A. , Srinivasan Rajagopalan
Published: April 2007

Crude distillation unit (CDU) operations are often defined in several operating modes, which are still being used by quite a few refineries for their planning. However, these operational modes cannot reflect all the ever‐changing operating conditions of a refinery. As a result, the CDU operation condition may be sub‐optimal and potential profit may be lost. This paper proposes a CDU model to decide the weight transfer ratio (WTR) ranges of CDU fractions from the operation modes. These WTR ranges are integrated into the refinery planning model to obtain the optimal CDU operation condition. Unlike the traditional linear CDU models that often omit the optimal solutions, or the rigorous simulation models that are time consuming to solve, the proposed CDU model can be easily solved with much higher accuracy than traditional linear models and better solution speed than the rigorous simulation models. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
High risk of human papillomavirus type 16 infections and of development of cervical squamous intraepithelial lesions in systemic lupus erythematosus patients
Authors: Nath Rahul , Mant Christine , Luxton Jennifer , Hughes Graham , Raju K. Shanti , Shepherd Phillip , Cason John
Published: April 2007

Objective

To determine rates of human papillomavirus (HPV) infections, abnormal cervical smears, and squamous intraepithelial lesions (SIL) among women with systemic lupus erythematosus (SLE).

Methods

We investigated 30 women with SLE, 67 with abnormal smears from colposcopy clinics, and 15 community subjects with normal smears. Polymerase chain reaction results for viral DNA and HPV‐16 sequencing data were correlated to cytology and colposcopic findings.

Results

SLE and colposcopy patients were more likely (P < 0.05) to be HPV positive (15 [54%] and 37 [67%] patients, respectively) and HPV‐16 DNA positive (16 [57%] and 17 [31%] patients, respectively) than community subjects (0% HPV DNA positive and 1 [6%] HPV‐16 DNA positive). SLE patients were also more likely to be HPV‐16 DNA positive than colposcopy patients (P < 0.05). SLE patients with a high HPV‐16 viral load more frequently had SIL (n = 6) than those with a low HPV‐16 viral load (n = 1; P < 0.05). HPV and HPV‐16 DNA positivity were not associated with previous or current drug therapy for SLE patients. All HPV‐16 DNA sequences from 6 SLE and 5 colposcopy patients were the European‐type variant. Eighteen (60%) SLE patients had a previous or current cervical abnormality. At the time of study, 5 (17%) SLE patients had an abnormal cervical smear and 8 (27%) had SIL. For those diagnosed with SLE for >10 years, the rate of SIL was 44% lower than those with SLE for <5 years (odds ratio 0.56, 95% confidence interval 0.1–3.5).

Conclusion

UK women with a recent SLE diagnosis had disturbingly elevated levels of HPV infections (particularly with European HPV‐16 variants at a high viral load), abnormal cervical cytology, and SIL.
Association between African American race/ethnicity and low bone mineral density in women with systemic lupus erythematosus
Authors: Lee Chin , Almagor Orit , Dunlop Dorothy D. , Chadha Anurekha B. , Manzi Susan , Spies Stewart , Ramsey‐Goldman Rosalind
Published: April 2007

Objective

To determine the association between race/ethnicity and bone mineral density (BMD) in women with systemic lupus erythematosus (SLE).

Methods

Women with SLE (n = 298), including 77 African Americans and 221 whites, completed this cross‐sectional study conducted from 1996 to 2002. Hip and lumbar spine BMD were measured by dual‐energy x‐ray absorptiometry. Study participants completed a self‐administered questionnaire and a physician completed the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). BMD results were expressed as Z scores. Analyses were performed to identify factors, including race/ethnicity, associated with low BMD defined as a Z score −1.0 or less at the hip or lumbar spine.

Results

African Americans compared with whites were younger at study visit (mean ± SD 39.7 ± 8.4 years versus 42.9 ± 11.6 years) and had higher SDI (mean ± SD 1.8 ± 2.0 versus 1.0 ± 1.6), but similar proportions of women were postmenopausal (31.2% versus 38.0%). African Americans had significantly lower mean BMD Z scores at the hip (−0.49 versus −0.07; group difference −0.41; 95% confidence interval [95% CI] −0.70, −0.13) and at the lumbar spine (−1.03 versus 0.10; group difference −1.13; 95% CI −1.48, −0.78) compared with whites. African American race/ethnicity was strongly associated with low BMD at the lumbar spine (adjusted odds ratio 4.42; 95% CI 2.19, 8.91) but not at the hip, adjusting for factors associated with low BMD.

Conclusion

African American women compared with white women with SLE had lower BMD at the hip and lumbar spine. African American race/ethnicity was associated with low BMD at the lumbar spine controlling for relevant clinical covariates.
Differences in the incidence of flares or new onset of inflammatory bowel diseases in patients with ankylosing spondylitis exposed to therapy with anti–tumor necrosis factor α agents
Authors: Braun J. , Baraliakos X. , Listing J. , Davis J. , van der Heijde D. , Haibel H. , Rudwaleit M. , Sieper J.
Published: April 2007

Objective

Ankylosing spondylitis (AS) and inflammatory bowel disease (IBD) are clinically and pathologically linked. Anti–tumor necrosis factor (anti‐TNF) agents are efficacious in treating AS, but not all are equally effective in treating IBD (Crohn's disease [CD] and ulcerative colitis [UC]). The purpose our study was to analyze the incidence of flares and new onset of IBD in patients with AS treated with anti‐TNF agents.

Methods

Data from 9 trials, 7 placebo‐controlled trials and 2 open studies, were analyzed.

Results

Data were available on 419 AS patients exposed to etanercept (625 patient‐years), 366 exposed to infliximab (618 patient‐years), 295 exposed to adalimumab (132 patient‐years), and 434 placebo patients (150 patient‐years). A history of IBD was reported in 76 of 1,130 patients (6.7%). There were 2 reports of IBD while receiving placebo (1.3 per 100 patient‐years), 1 while receiving infliximab, and 3 while receiving adalimumab. Among the 14 IBD cases receiving etanercept (2.2 per 100 patient‐years) there were 8 CD and 6 UC cases, significantly different from infliximab (P = 0.01) but not from placebo. Patients with a history of IBD had an IBD flare odds ratio of 18.0 (95% confidence interval [95% CI] 2–154) while taking etanercept and 4.2 (95% CI 0.4–44) while taking adalimumab, in comparison with infliximab. The incidence rates of new onset of IBD showed no significant difference between etanercept (0.8 per 100 patient‐years) and placebo (0.5 per 100 patient‐years).

Conclusion

New onset and flare of IBD are infrequent events in AS patients receiving anti‐TNF therapy. Infliximab (but not etanercept) largely prevents IBD activity. More data are required for adalimumab. The incidence of new onset of IBD was statistically not different from placebo for all anti‐TNF agents.
A multiethnic, multicenter cohort of patients with systemic lupus erythematosus (SLE) as a model for the study of ethnic disparities in SLE
Authors: Fernández Mónica , Alarcón Graciela S. , Calvo‐alén Jaime , Andrade Rosa , McGwin Gerald , Vilá Luis M. , Reveille John D. ,   LUMINA Study Group
Published: April 2007

Objective

To examine health disparities as a function of ethnicity using data from LUpus in MInorities, NAture versus nurture (LUMINA), a longitudinal study of patients with systemic lupus erythematosus (SLE); to build an explanatory model of how ethnic disparities occur in this setting; and to suggest appropriate interventions.

Methods

LUMINA patients (meeting American College of Rheumatology criteria for SLE) ages ≥16 years of African American, Hispanic (from Texas), Hispanic (from Puerto Rico), or Caucasian ethnicity were studied. In addition to examining the basic features of the cohort, we examined, by univariable and multivariable analyses, the factors associated with disease activity, damage accrual, lupus nephritis, and mortality. An empiric model based on the data presented (and the literature reviewed) was derived to explain the disparities observed.

Results

There were substantial differences in the socioeconomic/demographic, clinical, and genetic features among patients from the different ethnic groups, with Texan Hispanic and African American patients exhibiting overall a lower socioeconomic status, different genetic associations, more serious disease at a younger age, and worse intermediate and final outcomes than the Caucasian and Puerto Rican Hispanic patients. A model of disease outcome as a function of the disparities observed was created.

Conclusion

Ethnic disparities occur in SLE. Environmental, socioeconomic/demographic, psychosocial, genetic, and clinical factors play an important role as determinants of the ethnic differences observed. Measures aimed at eliminating these disparities are suggested while further research is conducted to elucidate the basis of these disparities and their changes at the societal level and to eliminate the gap between the rich and the poor.
Association of socioeconomic and demographic factors with utilization of rheumatology subspecialty care in systemic lupus erythematosus
Authors: Yazdany Jinoos , Gillis Joann Zell , Trupin Laura , Katz Patricia , Panopalis Pantelis , Criswell Lindsey A. , Yelin Edward
Published: April 2007

Objective

To examine the role of sociodemographic factors (age, race/ethnicity, and sex) and socioeconomic factors (income and education) in the utilization of rheumatology subspecialty care in a large cohort of subjects with systemic lupus erythematosus (SLE).

Methods

Data were derived from a cohort of 982 English‐speaking subjects with SLE. Between 2002 and 2004, trained survey workers administered a telephone survey to subjects eliciting information regarding demographics, SLE disease status, medications, health care utilization, health insurance, and socioeconomic status. We identified predictors of utilization of rheumatology subspecialty care, defined as at least 1 visit to a rheumatologist in the previous year. In addition, we examined factors associated with identifying any specialist as primarily responsible for SLE care.

Results

Older age, lower income, Medicare insurance, male sex, and less severe disease were associated with lack of rheumatology care. However, race/ethnicity and educational attainment were not significantly related to seeing a rheumatologist. After multivariate adjustment, only older age, lower income, and male sex remained associated with absence of rheumatology visits. Those least likely to identify a specialist as primarily responsible for their SLE care included older subjects and those reporting lower incomes.

Conclusion

Although elderly subjects and those with lower incomes traditionally have access to health care through the Medicare and Medicaid programs, the presence of health insurance alone did not ensure equal utilization of care. This finding suggests that additional barriers to accessing rheumatology subspecialty care may exist in these patient populations.
Influence of familial factors on radiologic disease progression over two years in siblings with osteoarthritis at multiple sites: A prospective longitudinal cohort study
Authors: Botha‐Scheepers Stella A. , Watt Iain , Slagboom Eline , Meulenbelt Ingrid , Rosendaal Frits R. , Breedveld Ferdinand C. , Kloppenburg Margreet
Published: April 2007

Objective

The contribution of genetics to osteoarthritis (OA) progression is not known. To gain more insight into whether familial factors play a role in disease progression of OA, we analyzed familial aggregation of radiologic OA progression in a study of sibling pairs (the Genetics, Arthrosis, and Progression [GARP] study).

Methods

A total of 105 white probands and their 105 siblings with OA at multiple joint sites were included in a prospective cohort study. Radiologic progression of OA was defined as a 1‐point score increase in total scores for severity of joint space narrowing (JSN) or osteophytes on standardized radiographs of the hands, knees, and hips obtained at baseline and after 2 years. Odds ratios were calculated for siblings and probands sharing radiologic disease progression.

Results

A total of 100 probands and 93 siblings were followed for 2 years (median age 60 years, 80% women). In 92 sibling pairs both the proband and sibling had complete radiographic followup. Radiologic progression of JSN and osteophytes was present in 47% and 42% of the probands and 34% and 37% of the siblings, respectively. The odds ratios (95% confidence intervals), adjusted for age, sex, and body mass index, of a sibling having radiologic progression if the proband had progression were 3.0 (1.2–7.8) for JSN progression and 1.5 (0.6–3.6) for osteophyte progression. A dose‐response relationship was found between the amount of increase in JSN total scores among probands and the progression of JSN in siblings.

Conclusion

Familial factors played a role in the radiologic progression of JSN over 2 years in patients with OA at multiple sites.
Accuracy of the diagnoses of spondylarthritides in veterans affairs medical center databases
Authors: Singh Jasvinder A. , Holmgren Aaron R. , Krug Hollis , Noorbaloochi Siamak
Published: April 2007

Objective

To study the accuracy of diagnoses of spondylarthritides in computerized databases at the Minneapolis Veterans Affairs Medical Center.

Methods

Medical records were available and reviewed for a random sample of 184 patients from a cohort of 737 patients seen at the rheumatology clinic between January 1, 2001 and July 31, 2002. We compared 4 database definitions with the medical record gold standard of rheumatologists' diagnosis of ankylosing spondylitis (AS), psoriatic arthritis (PsA), or reactive arthritis (ReA): presence of 1) ≥1 or 2) ≥2 International Classification of Diseases, Ninth Revision (ICD‐9) diagnostic codes for diagnoses of AS (720.0), PsA (696.0), and ReA (099.3, 711.11–711.19), and presence of 3) ≥1 or 4) ≥2 ICD‐9 codes and prescription of a disease‐modifying antirheumatic drug (DMARD). Accuracy was assessed by sensitivity, specificity, positive predictive values (PPVs) and negative predictive values (NPVs), kappa statistic, and receiver operator characteristic (ROC) curve area.

Results

Of 184 patients, 11 (6%) had AS, 17 (9%) had PsA, and 7 (4%) had ReA as per the gold standard. ICD‐9 codes for AS, PsA, and ReA were very specific (98–100%) with excellent NPV (99–100%) and PPV (83–100%), good to excellent sensitivity (57–100%), almost perfect kappa agreement (0.72–1), and high ROC curve area (0.79–1). Addition of presence of DMARD prescription to ICD‐9 codes of AS and PsA decreased sensitivity to 27–65% without improving the specificity (which was already high at 99–100%).

Conclusion

The ICD‐9 codes for AS, PsA, and ReA in databases are accurate. ICD‐9 codes may be used to identify cohorts of patients with spondylarthritides.
US national prevalence and correlates of low back and neck pain among adults
Authors: Strine Tara W. , Hootman Jennifer M.
Published: April 2007

Objective

To estimate the US prevalence and psychological and health behavior correlates of low back pain and/or neck pain. No current US national prevalence estimates of low back and neck pain exist and few studies have investigated the associations between low back and neck pain, psychological factors, and health behaviors in a representative sample of US community dwellers.

Methods

We analyzed data obtained from adults ages 18 years or older (n = 29,828) who participated in the 2002 National Health Interview Survey, a cross‐sectional, population‐based survey of US adults.

Results

The 3‐month US prevalence of back and/or neck pain was 31% (low back pain: 34 million, neck pain: 9 million, both back and neck pain: 19 million). Generally, adults with low back and/or neck pain reported more comorbid conditions, exhibited more psychological distress (including serious mental illness), and engaged in more risky health behaviors than adults without either condition.

Conclusion

Low back and neck pain are critical public health problems. Our study supports the idea of a multidimensional approach to examining low back and neck problems and suggests the need for further research to address potentially modifiable psychological factors and health behaviors in these populations.
Validation of a short form of the Western Ontario and McMaster Universities Osteoarthritis Index function subscale in hip and knee osteoarthritis
Authors: Baron Gabriel , Tubach Florence , Ravaud Philippe , Logeart Isabelle , Dougados Maxime
Published: April 2007

Objective

A short version of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function scale has recently been developed to enhance the applicability of the scale in routine practice and clinical research for patients with hip and knee osteoarthritis. The goal of the present study was to validate this short form.

Methods

We conducted a prospective 4‐week cohort study of 1,036 outpatients. Performance on the WOMAC function long form (LF) and short form (SF) was compared. Agreement between responses on the 2 forms was examined according to a Bland‐Altman plot. Responsiveness to change (by standardized response mean [SRM]), reproducibility (intraclass correlation coefficient [ICC]), and internal consistency (Cronbach's alpha) were computed for both forms. Construct validity was assessed based on functional impairment as measured on a numerical rating scale.

Results

At baseline, 24% of patients who completed the WOMAC LF had missing data for at least 1 item as compared with only 6% of patients who completed the WOMAC SF. The mean WOMAC SF score was greater than the mean WOMAC LF score (mean ± SD difference −4.3 ± 4.8 on a 0–100 scale). SRMs were 0.61 and 0.73, ICCs were 0.76 and 0.68, and Cronbach's alphas were 0.93 and 0.85 for the WOMAC LF and SF, respectively. The 2 forms had comparable correlation with functional impairment.

Conclusion

The WOMAC function short form has a low rate of missing data and is a responsive, reproducible, and valid measure. The mean SF score was 4 points higher than the mean LF score.
Tolerance and effectiveness of anti–tumor necrosis factor α therapies in elderly patients with rheumatoid arthritis: A population‐based cohort study
Authors: Genevay Stéphane , Finckh Axel , Ciurea Adrian , Chamot Anne‐Marie , Kyburz Diego , Gabay Cem ,   Physicians of the Swiss Clinical Quality Management Program for Rheumatoid Arthritis
Published: April 2007

Objective

Limited data have been published on tolerance to and efficacy of classic or biologic disease‐modifying antirheumatic drugs in elderly patients with rheumatoid arthritis (RA). The goal of the present study was to evaluate the tolerance to and effectiveness of anti–tumor necrosis factor (anti‐TNF) agents in elderly patients (≥65 years old) with RA (ERA) in comparison with younger patients (YRA).

Methods

The Swiss Clinical Quality Management program for RA is a longitudinal population‐based cohort. All patients who had received at least 1 dose of anti‐TNF agents between January 1997 and November 2005 were included and categorized according to their age. Tolerance was assessed by analyzing discontinuation rates of anti‐TNF agents. Effectiveness of these agents was assessed by analyzing RA disease activity (Disease Activity Score in 28 joints [DAS28]) and functional disability (Health Assessment Questionnaire [HAQ]) after anti‐TNF initiation.

Results

Among 1,571 patients with RA treated with anti‐TNF agents, 344 were ≥65 years of age at treatment initiation. Drug discontinuation rates (median time 3 years) and mean change in DAS28 scores at 2 years (–0.65 versus –0.58) were identical in ERA and YRA. However, HAQ score improved significantly less in ERA (–0.02) than in YRA (–0.1) and a subsequent analysis revealed that this finding was essentially due to patients >75 years of age.

Conclusion

Age in itself should not interfere with the decision to treat elderly patients with RA with anti‐TNF agents. In a subset of patients ages >75 years, no functional improvement according to HAQ should be expected despite improvements in disease activity.
Comparison of energy expenditure from lifestyle physical activities between patients with rheumatoid arthritis and healthy controls
Authors: Mancuso Carol A. , Rincon Melina , Sayles Wendy , Paget Stephen A.
Published: April 2007

Objective

Low energy expenditure is a risk for cardiovascular morbidity. The goals of this study were to compare energy expenditure between patients with rheumatoid arthritis (RA) and healthy controls.

Methods

A total of 121 RA patients and 120 healthy controls in New York City completed the Paffenbarger Physical Activity and Exercise Index at time of enrollment (1999–2000) and 1 year later to measure energy expenditure from walking, climbing stairs, and exercise/sports. Analyses were adjusted for age, sex, education, pain, social support, and depressive symptoms and were compared with recommended thresholds of energy expenditure.

Results

Participants' mean age was 49 years, and 87% were women. Patients with RA expended fewer kilocalories per week than controls (mean ± SD 1,474 ± 1,198 versus 1,958 ± 1,940, P = 0.003), with most of this difference from less walking as opposed to high‐intensity activities. Although similar percents of RA patients and controls met national recommendations for total weekly energy expenditure (56% versus 64% for the lower [≥1,000 kilocalories per week] threshold; P = 0.14, and 41% versus 48% for the higher [≥1,400 kilocalories per week] threshold; P = 0.17), fewer RA patients met the recommendations (≥700 kilocalories per week) for walking (32% versus 48%; P = 0.01). The strongest predictor of more energy expenditure at 1 year for both groups was more energy expenditure at enrollment.

Conclusion

Most of the difference in energy expenditure between RA patients and healthy controls was due to less walking. Given that walking is an effective and relatively safe lifestyle activity, increasing walking should be a priority to improve cardiovascular risk in RA.
Spannbetontragwerke von Straßenbrücken – Bemessungsvergleich nach neuen Nationalen Normen und bisherigen Europäischen Normen
Authors: Roßner Wolfgang
Published: April 2007

Mit Blick auf die endgültigen Europäischen Normen (EN) werden zunächst die Nachweiskonzepte der neuen Nationalen Normen (DIN) und der Europäischen Vornormen (ENV) unter Einschluss der zusätzlichen nationalen Regelungen gegenübergestellt und die vorhandenen Abweichungen aufgezeigt. Anschließend werden die daraus resultierenden Auswirkungen in den Grenzzuständen der Tragfähigkeit und der Gebrauchstauglichkeit verglichen und anhand einer einfeldrigen Spannbetonbrücke mit Kastenquerschnitt quantifiziert.
A Numerical Comparison of Some BAYESian Methods of Estimating a Binomial Parameter
Authors: Jones P. W.
Published: April 2007

This note considers the optimal and suboptimal sequential and fixed sample size estimation of the unknown binomial parameter, p, for a beta prior distribution for p and under quadratic loss and constant observation cost. A numerical comparison of the methods is presented.
Test Statistics for Simple MARKOV Chains. A Monte Carlo Study
Authors: Bedall Fritz K.
Published: April 2007

The statistical method for the analysis of frequency tables which has been published by GRIZZLE, STARMER, and KOCH (1969) is outlined for the case of linear functions of relative frequencies. Its use for the analysis of aggregate time series data under the model of simple MARKOV chains is suggested. Weighty objections against the resulting test statistics were grounds for the planning and performance of a Monte Carlo study. The results of the study demonstrated that the test statistic SS (Cb=0) which is used for the comparison of different MARKOV chains is in fact X2‐distributed. The test statistic SS (F(p) =Xb) for evaluation of the lack of fit of the model also follows a X2‐distribution when a simple MARKOV chain ∼ is used instead of the observed time series ∼ can be determined by simply iterating the original GSK algorithm.
On the Probabilities of Obtaining Negative Estimates of Genetic Variance Components
Authors: Tan W. Y. , Wong S. P.
Published: April 2007

This paper derives the probabilities of obtaining negative estimates of additive and dominance genetic variances when one uses the traditional weighted least square method for estimating genetic variances as given in MATHER and JINKS (1971). The model considered involves P1, P2, F2, B1 (Backcross to P1) and B2 (Backcross to P2). The results are derived under the ordinary assumptions as made in the genetic literatures. It is shown that unless the genetic effects are very large and environmental effects small, the probabilities of obtaining negative estimates of additive and dominance variances are in general quite large.
Zur numerischen Auswertung von Schnittflächenverteilungen. III
Authors: Voss K.
Published: April 2007

In this paper the connections between volume and absorption mass of objects resp. volume and absorption mass of segments are studied.
Testing Hypotheses in the Two‐period Change‐over with Binary Data
Authors: Zimmermann H. , Rahlfs V.
Published: April 2007

The paper proposes a general model for analysizing two‐period change‐over designs with binary data. The model includes tests for carry‐over effects, treatment and period effects in analogy to the well‐known ANOVA‐model for continuous data. Minimum modified χ2‐statistics are derived and formulas for desk calculators are given.
Model Construction and Model Examination on the Basis of Simulated Selection
Authors: Sumpf D. , Dietl G. , Just M.
Published: April 2007

By reason nonlinear relations founded between selection differential and realised selection response we have been made investigations about variants of the genetic‐statistical model, which include this nonlinearity. The variations of the model would not only referred to the postulate pattern of the connection between phenotype, genotype and environment but also enclosed the postulate assumption about the distribution of the variates. In an investigated special case the linear model equation P = G ± e was held, however the distributions of P and G were defined over a limited range in one direction. For P we have defined a modified normal distribution and the distribution of the random vector (G, e) non normal regarded with cov (G, e) ≠ 0, By means of a solution set of an integral equation a density function of the random vector (P, G) has been received, in which the expectation of the selection response of the usual genetic‐statistical model approximate is included as a special case. The genetical parameters has been derived, which result from changed model. However their representation was only possible partially as an integral function. A subsequent paper informs of the examination this mode! variants, which depend on a parameter of the nonlinearity c.
An Unbalanced Two‐way Model With Random Effects Having Unequal Variances
Authors: Hussein M. , Milliken G. A.
Published: April 2007

Consider the model yijk=u ± ai ± bi ± cij ± eijk i=1, 2,…, t; j=1, 2,…b; k=1, 2,…,nij where μ is a constant and ai, bi, cij are distributed independently and normally with zero means and variances Δ2 Δ2/bdij and δ2 respectively. It is assumed that di's, and dij's are known (positive) constants (for all i and j). In this paper procedures for estimating the variance components (Δ2, Δ2b and Δ2a) and for testing the hypothesis Hoc:Δ2c/Δ2 = y3 and Hoa:Δ2b/Δ2 = y4 (where y2, y3, and y4, are specified constants) are presented. A generalization for the mixed model case is discussed in the last section.
A New Nonparametric Approach to the Comparison of K Independent Samples of Response Curves
Authors: Lehmacher W. , Wall K. D.
Published: April 2007

Two simultaneous distribution free test procedures to test the homogeneity of K samples of response curves measured at T points of time each are proposed which react upon the shape of the response curve. One procedure is based on the comparison of K T‐tupels of FRIEDMAN‐rank sums, the other on the comparison of K T × T‐incidence tables, which first were introduced by KANNEMANN (1976). The application of the two procedures is illustrated by a numerical example. In the discussion the tests are compared with each other and with concurring tests.
A Simulation Study of Two Paired Sequential Designs by I. D. BROSS
Authors: Page W. F.
Published: April 2007

Two sequential charts designed by I. BROSS, used to analyze serial data for two treatment groups, are studied in this paper. Simulation techniques, rather than theoretical calculations, have been used to determine more complete characteristics of these designs. Of particular interest are the estimates of percentiles of the distribution function of “sample size required to reach a statistical decision”. The distribution parameters of the one‐sided tests, not studied by BROSS, are also given.

Es werden 2 sequentielle Pläne von I. BROSS untersucht, die zur Analyse von seriellen Daten für 2 Behandlungsgruppen verwendet werden können. Um diese Pläne umfassender zu charakterisieren, wurde die Simulationstechnik eingesetzt. Von besonderem Interesse waren Abschätzungen von Perzentilen der Verteilungsfunktion der “erforderlichen Stichprobengröße, um eine statistische Entscheidung zu treffen”. Es werden Verteilungsparameter von einseitigen Tests angegeben.
Die Signimaxrotation — ein weiterer Versuch, Faktorenstrukturen interpretationsgünstig zu rotieren
Authors: Schiller W.
Published: April 2007

A new method of rotation in factor analysis is introduced, the Signimaxrotation. By this tool the number of the significant factor‐values can be maximated. The basis of its criterion of rotation are the distances between the nonsignificant factor‐values and the nearest limitation of significance and also the number of non‐significant factor‐values. In some examples it is shown that the Signimaxrotation yields results, better than these one of a Varimaxrotation or the visual rotation.

Es wird ein neues Rotationsverfahren der Faktoranalyse vorgestellt, die Signimaxrotation. Mit ihr soll die Anzahl der signifikanten Ladungen einer Faktorenstruktur maximiert werden. Grundlagen ihres Rotationskriteriums sind die Abstände der nichtsiguifikanten Ladungen von der nächstgelegenen Signifikanzgrenze sowie die Anzahl der nichtsiguifikanten Ladungen. In Beispielen wird gezeigt, daß die Signimaxrotation bessere Ergebnisse liefert als die Varimaxrotation oder die visuelle Rotation.
Sequential Classification Based on Regression
Authors: KrzyŚAko M.
Published: April 2007

Let us consider m general populations π1, …,πm. Each object belonging to these populations is represented by (p ± 1) characteristics x1, x2,…,xp,y. A certain object, which is an element of one of the m general populations π1,…,πm has to be classified into the correct population. It will be assumed that knowledge of the value of the characteristic y would permit its correct classification, but that the observation of this characteristic is expensive, difficult or dangerous, as e.g. in medical applications. y is correlated with a set of p characteristics x1,x2,…,xp, which are observed sequentially. The classification procedure is based on the division of the space of the observed value of characteristics x1,x2,…,xp into nonintersecting areas determined so as to minimize the value of BAYES' risk given by equation (3).
Discriminant Analysis of Biological Shape Profile for Hybridization
Authors: Misra R. K.
Published: April 2007

Role of hybridization on growth, nomenclature, speciation, genetics and wildlife management is widely recognised. New situations of hybridization are being discovered and studied yearly (SHORT, 1965). Changes of size make changes of shape and proportions necessary (AlEXANDER, 1971) and for constant efficiency of many body functions (e.g., the locomotory, respiratory and the digestive) systematic size‐correlated alteration of physical shape is an adaptive necessity for many organic relationships (GOULD, 1966). Need for analysing shape for hybridization is therefore obvious. Often an objective of studying hybridization is to estimate the degree of suspected hybrids and thereby specify the distribution of the hybrids in relation to the two parental species, A study of hybridization must recognise the effects of the additive genetic (A) as well as the nonadditive genetic sources (see, e.g., MISRA, 1975a). Discriminant analysis offers a powerful tool for studies of hybrid zones or zones of abrupt phenetic transition, as it is based on the maximisation of differences between biologically meaningful reference samples (ROHWER, 1972). This paper presents a discriminant analysis of biological shape profiles for hybridization based on A and NA sources.
Zur numerischen Auswertung von Schnittflächenverteilungen. IV
Authors: Voss K.
Published: April 2007

In this paper a general integral equation is given for the connection between the size distribution of similar formed objects and the size distribution of their sections with zero thickness. The spherical problem is enclosed in this solution. The integral kernels for six simple polyhedrons are numerically given. The integral geometry is the theoretical basis for this paper, and the computer simulation of the section process is the practical method for the numerical calculation of integral kernels.
Small Sample Distribution and Power of the Binomial Index of Dispersion and Log Likelihood Ratio Tests
Authors: Bennett B. M. , Kaneshiro C.
Published: April 2007

This paper considers the exact distribution of the X2 index of dispersion and ‐2 log (likelihood ratio) tests for the hypothesis of homogeneity of c independent samples from a common binomial population. The exact significance levels and power of these tests under ‘logit’ alternatives are compared numerically for the cases: c = 3, 4, 5 and various sample sizes. n1 = 5,10 for i = 1,…, c.
Application of some Multivariate Analysis Techniques to Data on Effect of Air‐Pollution on Morbidity
Authors: Sahai H.
Published: April 2007

In this article an attempt has been made to analyze the data obtained from an air‐pollution study to investigate the effects of the levels of air pollution exposure in causing morbidity, using some multivariate statistical techniques. Considering the importance of the theoretical aspect of the problem, the usual theory related to the application of these methods has also been described.
The Probability Density Functions of the Contingency Coefficients, defined by KRAMER and PEARSON, in a 2‐Dimensional Frequency Distribution of Grouped Bivariate Normal Variables. I
Authors: Knauer S.
Published: April 2007

Two general measures for the degree of association in a contingency table are the contingency coefficients defined by PEARSON and KRAMER. In the case of a standardized bivariate normal distribution with correlation coefficient of the variables, whose realizations constitute the rows and columns of the table, the density functions of the two listed association measures are derived.
Hierarchical Classification II: Complete‐Linkage Method
Authors: Kopp B.
Published: April 2007

The second part of our survey of hierarchical joining methods deals with the Maximum Method. Both the Maximum Method and the Minimum Method lie at the extremes of PEAY'S r‐clique methods.
An Application of the Logistic Distribution to the Analysis of a Measles Epidemic
Authors: Slymen D. J. , Woolson R. F. , Myers M. G.
Published: April 2007

The relationship between the development of measles and age at immunization and time since immunization is examined using a trichotomous logistic distribution with maximum likelihood estimation of the parameters. The first and second partial derivatives used in the estimation scheme are presented.
Expected Error Rates for Logistic Regression Versus Normal Discriminant Analysis
Authors: McLachlan G. J. , Byth K.
Published: April 2007

The expected error rates associated with using the allocation rule based on logistic regression are derived in the context of two multivariate normal populations with a common covariance matrix and compared with the corresponding error rates of the classical rule based on this normality assumption. It is shown in terms of the actual sizes of the asymptotic expected error rates that the performance of the logistic procedure does not fall far short of the normality based method, even for widely separated populations. This latter result is not obvious from previously available work on the asymptotic relative efficiency of the logistic procedure.
On the Efficiency Factor for a Contrast of Treatment Parameters
Authors: Ceranka B. , Mejza S.
Published: April 2007

In this paper a formula for computing the efficiency factor of a block design for any estimable contrast of treatment parameters is given. The formula is expressible in terms of the efficiency factors of some basic contrasts.
A New Nonparametric Approach to the Comparison of K Independent Samples of Response Curves II: A K Sample Generalization of the FRIEDMAN Test
Authors: Lehmacher W.
Published: April 2007

A K sample generalization of the FRIEDMAN test (1937) is introduced which can be used as a nonparametric procedure for testing the homogeneity of the profiles of K independent samples of response curves measured at T identical points of time. While a similar procedure in LEHMACHER & WALL (1978), section 3, is based on T combined tests, each of them at level a/T, here a finite and asymptotic test is presented which is based on a single test statistic. The application of the new multivariate test is illustrated by the same numerical example as in LEHMACHER & WALL (1978). The properties of this test are discussed and compared with the combined test mentioned above.
Estimation of Attributable Risk in the Presence of Confounding
Authors: Ejigou Ayenew
Published: April 2007

LEVIN's attributable risk due to a risk factor is estimated in the presence of confounding in the retrospective study context. The crude attributable risk is decomposed into the attributable risk due to a risk factor and a bias factor which is shown to vanish only when the confounding factor is unassociated to either the risk factor or the Disease or to both. Asymptotic tests are provided for testing interaction, and an appropriate pooled estimate is derived when constancy of partial attributable risks prevails over the levels of the confounding factor.