TRC-PAD: Accelerating Recruitment of AD Clinical Trials through Innovative Information Technology

BACKGROUND

The Trial-Ready Cohort for Preclinical/Prodromal Alzheimer's Disease (TRC-PAD) Informatics Platform (TRC-PAD IP) was developed to facilitate the efficient selection, recruitment, and assessment of study participants in support of the TRC-PAD program.

OBJECTIVES

Describe the innovative architecture, workflows, and components of the TRC-PAD IP.

DESIGN

The TRC-PAD IP was conceived as a secure, scalable, multi-tiered information management platform designed to facilitate high-throughput, cost-effective selection, recruitment, and assessment of TRC-PAD study participants and to develop a learning algorithm to select amyloid-bearing participants to participate in trials of early-stage Alzheimer's disease.

SETTING

TRC-PAD participants were evaluated using both web-based and in-person assessments to predict their risk of amyloid biomarker abnormalities and eligibility for preclinical and prodromal clinical trials. Participant data were integrated across multiple stages to inform the prediction of amyloid biomarker elevation.

PARTICIPANTS

TRC-PAD participants were age 50 and above, with an interest in participating in Alzheimer's research.

MEASUREMENTS

TRC-PAD participants' cognitive performance and subjective memory concerns were remotely assessed on a longitudinal basis to predict participant risk of biomarker abnormalities. Those participants determined to be at the highest risk were invited to an in-clinic screening visit for a full battery of clinical and cognitive assessments and amyloid biomarker confirmation using positron emission tomography (PET) or lumbar puncture (LP).

RESULTS

The TRC-PAD IP supported growth in recruitment, screening, and enrollment of TRC-PAD participants by leveraging a secure, scalable, cost-effective cloud-based information technology architecture.

CONCLUSIONS

The TRC-PAD program and its underlying information management infrastructure, TRC-PAD IP, have demonstrated feasibility concerning the program aims. The flexible and modular design of the TRC-PAD IP will accommodate the introduction of emerging diagnostic technologies.

EU/US/CTAD Task Force: Lessons Learned from Recent and Current Alzheimer's Prevention Trials

At a meeting of the EU/US/Clinical Trials in Alzheimer's Disease (CTAD) Task Force in December 2016, an international group of investigators from industry, academia, and regulatory agencies reviewed lessons learned from ongoing and planned prevention trials, which will help guide future clinical trials of AD treatments, particularly in the pre-clinical space. The Task Force discussed challenges that need to be addressed across all aspects of clinical trials, calling for innovation in recruitment and retention, infrastructure development, and the selection of outcome measures. While cognitive change provides a marker of disease progression across the disease continuum, there remains a need to identify the optimal assessment tools that provide clinically meaningful endpoints. Patient- and informant-reported assessments of cognition and function may be useful but present additional challenges. Imaging and other biomarkers are also essential to maximize the efficiency of and the information learned from clinical trials.

Alzheimer's disease therapeutic trials: EU/US Task Force report on recruitment, retention, and methodology

While we may not be able to find a cure for Alzheimer's disease (AD) in the near future, several drugs presently in trials have shown promise as possible modifiers of disease progression. However, we may not be able to demonstrate efficacy due to issues of recruitment, retention, site-to-site variability, and other methodological issues. It is thus incumbent on the scientific community to find solutions to these problems, particularly as the field moves toward preventing illness or treating the disease in its prodromal stages, where these methodological issues will become even more critical. We need to better understand why participants agree or refuse to enter drug trials, and why both primary care physicians and Alzheimer's specialists agree or refuse to involve their patients. We also need to quantify the impact of requiring imaging studies, extensive questionnaires, cognitive testing, and lumbar punctures on recruitment and retention. With these concerns in mind, an international task force meeting of experts from academia and industry in the United States, European Union, and Japan in San Diego, California on November 2, 2011 to focus on recruitment, retention and other methodological issues related to clinical trials for AD. Based on the recommendations of this Task force meeting, this Perspectives article critically reflects on the most critical and timely methodological issues related to recruitment and retention in prevention and therapeutic trials in AD, which are paralleled by a paradigm shift in the diagnostic conceptualization of this disease, as reflected by recently new proposed diagnostic criteria involving preclinical stages of the disease.

Report of the task force on designing clinical trials in early (predementia) AD

BACKGROUND

A large number of promising candidate disease-modifying treatments for Alzheimer disease (AD) continue to advance into phase II and phase III testing. However, most completed trials have failed to demonstrate efficacy, and there is growing concern that methodologic difficulties may contribute to these clinical trial failures. The optimal time to intervene with such treatments is probably in the years prior to the onset of dementia, before the neuropathology has progressed to the advanced stage corresponding to clinical dementia.

METHOD

An international task force of individuals from academia, industry, nonprofit foundations, and regulatory agencies was convened to discuss optimal trial design in early (predementia) AD.

RESULTS

General consensus was reached on key principles involving the scope of the AD diagnosis, the selection of subjects for trials, outcome measures, and analytical methods.

CONCLUSION

A consensus has been achieved in support of the testing of candidate treatments in the early (predementia) AD population.

Six-month atrophy in MTL structures is associated with subsequent memory decline in elderly controls

Neurodegeneration precedes the onset of dementias such as Alzheimer's by several years. Recent advances in volumetric imaging allow quantification of subtle neuroanatomical change over time periods as short as six months. This study investigates whether neuroanatomical change in medial temporal lobe subregions is associated with later memory decline in elderly controls. Using high-resolution, T1-weighted magnetic resonance images acquired at baseline and six-month follow-up, change in cortical thickness and subcortical volumes was measured in 142 healthy elderly subjects (aged 59-90 years) from the ADNI cohort. Regression analysis was used to identify whether change in fourteen subregions, selected a priori, was associated with declining performance on memory tests from baseline to two-year follow-up. Percent thickness change in the right fusiform and inferior temporal cortices and expansion of the right inferior lateral ventricle were found to be significant predictors of subsequent decline on memory-specific neuropsychological measures. These results demonstrate that six-month regional neurodegeneration can be quantified in the healthy elderly and might help identify those at risk for subsequent cognitive decline.

Enrichment through biomarkers in clinical trials of Alzheimer's drugs in patients with mild cognitive impairment

Clinical trials of disease modifying drugs for Alzheimer's disease (AD) in patients with mild cognitive impairment (MCI) might benefit from enrichment with true AD cases. Four hundred five MCI patients (143 converters and 262 nonconverters to AD within 2 years) of the Alzheimer's disease Neuroimaging Initiative (ADNI) were used. Markers for enrichment were hippocampal atrophy on magnetic resonance (MRI), temporoparietal hypometabolism on FDG PET, cerebrospinal fluid (CSF) biomarkers (Abeta42, tau, and phospho-tau), and cortical amyloid deposition (11C-PIB positron emission tomography (PET)). Two separate enrichment strategies were tested to A) maximize the proportion of MCI converters screened in, and B) minimize the proportion of MCI converters screened out. Based on strategy A, when compared with no enrichment and ADAS-Cog as an outcome measure (sample size of 834), enrichment with 18F-FDG PET and hippocampal volume lowered samples size to 260 and 277 cases per arm, but at the cost of screening out 1,597 and 434 cases per arm. When compared with no enrichment and clinical dementia rating (CDR-SOB) as an outcome measure (sample size of 674), enrichment with hippocampal volume and Abeta42 lowered sample sizes to 191 and 291 cases per arm, with 639 and 157 screened out cases. Strategy B reduced the number of screened out cases (740 for [11C]-PIB PET, 101 hippocampal volume, 82 ADAS-COG and 330 for [18F]-FDG PET) but at the expense of decreased power and a relative increase size (740 for [11C]-PIB PET, 676 for hippocampal volume, 744 for ADAS-Cog, and 517 for [18F]-FDG PET). Enrichment comes at the price of an often relevant proportion of screened out cases, and in clinical trial settings, the balance between enrichment of screened in and loss of screened out patients should be critically discussed.

Predicting virulence of Aeromonas isolates based on changes in transcription of c-jun and c-fos in human tissue culture cells

AIMS

To screen for the virulence potential of Aeromonas isolates based on the change in regulation of c-jun and c-fos in the human intestinal tissue culture cell line Caco-2.

METHODS AND RESULTS

Aeromonas cells were added to Caco-2 cells at a ratio of approx. 1 : 1. After 1-, 2- and 3-h incubation at 37 degrees C, mRNA was extracted from the cells and gene expression of two host genes, c-jun and c-fos, quantified. Aeromonas isolates which were pathogenic in the neonatal mouse model demonstrated up-regulation of c-jun and c-fos compared to avirulent isolates.

CONCLUSIONS

Human cell culture results showed that c-jun and c-fos were predictive of Aeromonas virulence.

SIGNIFICANCE AND IMPACT OF THE STUDY

An Aeromonas relative virulence scale is proposed for use in the testing of Aeromonas drinking water isolates.

Pooled analysis of antidepressant levels in lactating mothers, breast milk, and nursing infants

OBJECTIVE

The available data on antidepressant levels in nursing infants were analyzed in order to calculate average infant drug levels and determine what factors influence plasma drug levels in breast-feeding infants of mothers treated with antidepressants.

METHOD

Electronic searches of MEDLINE, PreMEDLINE, Current Contents, Biological Abstracts, and PsycINFO from 1966 through July 2002 followed by bibliographic searches identified 67 relevant studies (two unpublished). By consensus the authors identified 57 studies of maternal plasma, breast milk, and/or infant plasma antidepressant levels from nursing mother-infant pairs, measured by liquid chromatography.

RESULTS

Infants with recent prenatal exposure and symptomatic infants included in case reports were analyzed separately. Infant plasma levels were standardized against the average maternal level for each drug. The average infant-maternal plasma ratio was calculated for each drug, and correlations of infant plasma level to maternal dose, maternal plasma level, and breast milk level were calculated. Nortriptyline, paroxetine, and sertraline usually produce undetectable infant levels. Of drugs currently used, fluoxetine produces the highest proportion (22%) of infant levels that are elevated above 10% of the average maternal level. Based on smaller numbers, the data on citalopram indicate that it produces elevated levels in 17% of infants. The milk-to-plasma ratios for 11 antidepressants had a statistically significant negative association with the percentage of the drug bound to protein.

CONCLUSIONS

Nortriptyline, paroxetine, and sertraline may be preferred choices in breast-feeding women. Minimizing the maternal dose may be helpful with citalopram. Current data do not support monitoring breast milk levels in individual patients. Future researchers should report maternal, breast milk, and infant antidepressant levels along with other appropriate variables.

High-throughput gene discovery in the rat

The rat is an important animal model for human diseases and is widely used in physiology. In this article we present a new strategy for gene discovery based on the production of ESTs from serially subtracted and normalized cDNA libraries, and we describe its application for the development of a comprehensive nonredundant collection of rat ESTs. Our new strategy appears to yield substantially more EST clusters per ESTs sequenced than do previous approaches that did not use serial subtraction. However, multiple rounds of library subtraction resulted in high frequencies of otherwise rare internally primed cDNAs, defining the limits of this powerful approach. To date, we have generated >200,000 3' ESTs from >100 cDNA libraries representing a wide range of tissues and developmental stages of the laboratory rat. Most importantly, we have contributed to approximately 50,000 rat UniGene clusters. We have identified, arrayed, and derived 5' ESTs from >30,000 unique rat cDNA clones. Complete information, including radiation hybrid mapping data, is also maintained locally at http://genome.uiowa.edu/clcg.html. All of the sequences described in this article have been submitted to the dbEST division of the NCBI.

Anopheles gambiae pilot gene discovery project: identification of mosquito innate immunity genes from expressed sequence tags generated from immune-competent cell lines

Together with AIDS and tuberculosis, malaria is at the top of the list of devastating infectious diseases. However, molecular genetic studies of its major vector, Anopheles gambiae, are still quite limited. We have conducted a pilot gene discovery project to accelerate progress in the molecular analysis of vector biology, with emphasis on the mosquito's antimalarial immune defense. A total of 5,925 expressed sequence tags were determined from normalized cDNA libraries derived from immune-responsive hemocyte-like cell lines. The 3,242 expressed sequence tag-containing cDNA clones were grouped into 2,380 clone clusters, potentially representing unique genes. Of these, 1,118 showed similarities to known genes from other organisms, but only 27 were identical to previously known mosquito genes. We identified 38 candidate genes, based on sequence similarity, that may be implicated in immune reactions including antimalarial defense; 19 of these were shown experimentally to be inducible by bacterial challenge, lending support to their proposed involvement in mosquito immunity.

Evolution of techniques for ultrasound-guided palladium 103 brachytherapy in 950 patients with prostate cancer

PURPOSE

Brachytherapy is an effective, low-morbidity, cost-effective treatment for adenocarcinoma of the prostate. Although both iodine 125 and palladium 103 have been used extensively over the last 14 years, 103Pd (Theraseed) provides a more rapid initial dose and therefore better control of higher Gleason grade tumors. We assessed a highly refined methodology for 103Pd brachytherapy in patients with prostate cancer and compared outcomes before and after making adjustments in technique.

MATERIALS AND METHODS

Standard brachytherapy techniques were modified to include combination of preplanning with real-time adjustment, placing all needles at once to minimize prostate movement, using monitored anesthesia control sedation during preoperative volume study and cystoscopy, and several other small but important changes. Charts were reviewed from 950 patients treated with 103Pd implants from 1991 through 1999. Prostate-specific antigen (PSA) and biopsy data before and after 1993 were compared for 733 patients whose data qualified for analysis.

RESULTS

At 1 and 5 years after treatment, 85-88% of patients had stable PSA <1.5 ng/mL. Biopsies were negative in 90-94% at 2 years.

CONCLUSION

The modification in techniques provides positive results that remain stable over time.

Minimally invasive treatment for localized adenocarcinoma of the prostate: review of 1048 patients treated with ultrasound-guided palladium-103 brachytherapy

PURPOSE

To assess the effectiveness of palladium-103 brachytherapy in stage T1 and T2 adenocarcinoma of the prostate.

PATIENTS AND METHODS

The charts of 1048 patients treated between 1991 and 1999 with transperineal realtime ultrasound-guided (103)Pd (Theraseed) implants were reviewed to assess the effects on serum prostate specific antigen (PSA) values and tissue (biopsy). Of the 1048 patients, 780 had sufficient data for this report. Preoperative total androgen blockade (leuprolide and flutamide) was used selectively in patients whose prostate size was >50 cc and those whose tumors had a Gleason score of >7.

RESULTS

At 1 year, 86% of the evaluable 766 patients had stable PSA concentration <1.5 ng/mL; at 5 years, 86% of the 166 patients with data available had stable PSA values <1.5 ng/mL. Biopsies were negative in 92% of the patients studied at 2 years. Patients with pretreatment PSA values <10 ng/mL had the best outcomes, and those treated with (103)Pd plus hormone ablation achieved PSA reduction more rapidly than those treated with radioisotope monotherapy. There was one disease-related death; the principal morbidity was short-term bladder and bowel irritation without permanent sequelae. Impotence occurred in approximately 15% of patients, and incontinence occurred in 5% of those who had undergone prior transurethral resection of the prostate.

CONCLUSION

The technique used in this study proved effective in reducing PSA concentrations to <1.5 ng/mL and in producing negative biopsies 1 and 2 years postoperatively. These results are comparable to those of external-beam radiation therapy and radical prostatectomy while demonstrating a significant reduction in morbidity.

Computed tomography of Paget disease of the skull versus fibrous dysplasia

OBJECTIVE

Radiologists are often challenged to review CT examinations of the skull without pertinent clinical information or plain radiographs. Skull lesions of fibrous dysplasia (FD) may often be confused with Paget disease (PD). The purpose of this article is to evaluate radiographic similarities and to find the signs that can differentiate PD from FD of the skull on head CT and to describe the CT imaging features of PD and FD.

DESIGN AND PATIENTS

CT scans of the skull in eight cases of PD, 18 cases of FD (13 cases of skull and facial bones, five cases of only facial bones) and 10 normals were studied retrospectively.

RESULTS

Ten features were found to be similar in PD and FD and 10 other features were found to be dissimilar. The frequency of the 10 differentiating features was evaluated to determine their reliability in distinguishing one disorder from the other. The differentiating features in order of significance include: (1) "groundglass" appearance, (2) symmetry, (3) involvement of the paranasal sinuses, (4) thickness of the cranial cortices, (5) involvement of the sphenoid bone, (6) orbital involvement, (7) nasal cavity involvement, (8) presence of a soft tissue mass, (9) maxillary involvement, and (10) the presence of cyst-like changes.

CONCLUSION

These 10 signs improve the radiologist's skill in differentiating FD and PD.

The role of consumers in health care decision making

This paper focuses on the results of a survey of chief executive officers and consumer board members of Ontario hospitals and community health centres regarding the role of consumers in health care decision making. The opinions of both the chief executive officer and consumer board member respondents were elicited regarding the value of consumer input in decision making for the organizations studied. Results indicate that consumer board members feel that their input into organizational decision making is valued, chief executive officers value the input of consumers, and consumer involvement in decision making is increasing. More women are now involved on boards of the organizations studied, but visible minority representation remains low on hospital boards. Consumer board members feel that their decision making is influenced by providers on the board.

Determining Surface Areas from Linear Adsorption Isotherms at Supercritical Conditions

Here we demonstrate that there is a wide range of pressures at supercritical temperatures where there is essentially monolayer coverage (i.e., there is nearly a complete layer of molecules adsorbed adjacent to the surface, but very little excess density in the second and subsequent layers). In this regime, the dependence of the Gibbs adsorption on the density is linear, and coefficients of this linear function depend on the monolayer capacity and surface area. It is shown that measurements of the Gibbs adsorption in this regime can be used to determine surface area without knowledge of the area per molecule or a model for the adsorption isotherm. This new method has the potential to provide reliable values of specific surface area for macroporous, mesoporous, and microporous systems without the limitations of previous methods. Lattice-theory calculations suggest that the best conditions for surface area measurements are in the supercritical region with temperatures about twice the critical temperature and pressures well above the critical pressure. These conditions allow nearly complete monolayer coverage but there is not multilayer adsorption because the temperature is sufficiently above the critical temperature of the adsorbate. Copyright 1997 Academic Press. Copyright 1997Academic Press

An ammonium pulse inhibits fluid secretion

Exposing perfused mandibular salivary glands to a 5-min pulse of NH4Cl almost totally inhibited fluid secretion evoked by acetylcholine. Recovery from exposure to 0.5 mM NH4Cl occurred within 10 min, but after exposure to 20 mM NH4Cl recovery was not complete even after 30 min. The inhibition could not be explained by changes in intracellular pH as there was no acidosis measurable after the 0.5 mM NH4Cl pulse. NH4Cl did not inhibit intracellular calcium release by acetylcholine so that receptor inhibition could not be the explanation for the inhibition of secretion. These observations indicate that data obtained from ammonium pulse experiments should be interpreted with caution.

Effect of hypolipidemic drugs gemfibrozil, ciprofibrate, and clofibric acid on peroxisomal beta-oxidation in primary cultures of rainbow trout hepatocytes

Primary cultures of hepatocytes were established from sexually mature male rainbow trout (Oncorhyncus mykiss) and treated with the hypolipidemic drugs gemfibrozil (0.25-1.25 mM), clofibric acid (2.25-3.00 mM), or ciprofibrate (0.25-1.00 mM). Significant dose-related increases in peroxisomal fatty acyl-CoA oxidase (FACO) were seen after exposure for 48 hr to clofibric acid (P < 0.01) and ciprofibrate (P < 0.05) but not gemfibrozil (P = 0.08). Strong correlation was obtained between increased acyl-CoA oxidase activity and the relative amount of peroxisomal bifunctional enzyme (PBE), further supporting evidence of a proliferative effect. These preliminary studies demonstrate that peroxisomal beta-oxidation can be induced in vitro in a primary rainbow trout hepatocyte system.

Comparison of knee motion and callus formation in femoral lengthening with the Wagner or monolateral-ring device

Twenty-three patients who underwent femoral lengthening had proximal fixation with two Shanz screws; however, the type of distal fixation and site of the osteotomy differed. One group had distal fixation with two Shanz screws attached to a Wagner device and had a midshaft osteotomy; the other group had distal fixation with an Ilizarov ring attached to a modified Wagner device and underwent metaphyseal osteotomy. Patients were compared with regard to callus formation, presence of knee subluxation, and range of motion (ROM) at the knee. The average lengthening achieved was 9.9 cm. The type of bone healing was superior when the osteotomy was performed in the metaphysis rather than to the diaphysis. Knee ROM was poorer in the group with the distal fixation by the Ilizarov wires than the group with the Shanz pins. Multiple adhesions caused by Ilizarov wire impalement of muscles appeared to have caused the excessive stiffness. In instances of simultaneous ipsilateral lengthening of the femur and tibia, interconnection of the Ilizarov ring by means of hinges was successful in reducing the incidence of knee subluxation.

Composite resin bond strength after enamel bleaching

This study evaluated the effect of enamel bleaching with a commercial product on the sheer bond strength of a composite resin. A total of 45 human extracted permanent molars were used. A flat enamel surface was obtained with 600-grit SiC paper. The teeth were then randomly distributed into three groups of 15 teeth each: Group 1: Enamel etching with 37% phosphoric acid gel (Coe) for 60 seconds, placement of an unfilled resin (Coe) thinly applied with a brush and a composite resin (Occlusin); Group 2: Enamel bleaching (Rembrandt Lighten Bleaching Gel, Den-Mat) for one hour, etching for 60 seconds and placement of unfilled and composite resins. Group 3: Enamel bleaching for 24 hours, etching for 60 seconds, and placement of unfilled and composite resins. A nylon ring over the etched enamel retained the composite resin. The teeth were thermocycled (X100) and sheared with a knife-edged blade in an Instron machine running at a cross-head speed of 1 mm/min. The results in MPa were: Group 1: 12.86 +/- 4.83, Group 2: 12.33 +/- 2.95, and Group 3: 7.67 +/- 1.98. An ANOVA revealed that Groups 1 and 2 were significantly different from Group 3 (P < 0.001). Fracture within the enamel occurred in 53% in Group 1, 33% in Group 2, and 0% in Group 3. The study reveals that the shear bond strength of composite resins is significantly reduced after enamel bleaching for 24 hours.

Effect of a fluoridated etchant on the shear bond strength of a composite resin to enamel

The purpose of this study was to evaluate the effect of a fluoridated etching gel on the shear bond strength of a composite resin to enamel. A total of 75 extracted human permanent molars were used. A flat enamel surface was obtained with 600-grit silicon carbide paper and cleaned with a rubber cup and a water slurry of fine flour of pumice. The teeth were randomly distributed into 5 groups of 15 teeth each and etched as follows: group 1: 37% non-fluoridated phosphoric acid gel (Coe) for 60 seconds (control); group 2: 60% phosphoric acid gel with 0.5% NaF (Orthoprep) for 5 seconds; group 3: Orthoprep for 15 seconds; group 4: Orthoprep for 30 seconds; group 5: Orthoprep for 60 seconds. After etching, rinsing and drying, an unfilled resin (Coe Bond) was thinly applied with a brush and cured for 30 seconds. A nylon ring was placed over the area and filled with a light-cured composite resin (Occlusin). The teeth were thermocyled (100x), mounted in plastic cups and plaster, and sheared with a knife-edged blade in an Instron machine running at a crosshead speed of 1 mm/min. The results in MPa were as follows: group 1: 14.49 +/- 4.43; group 2: 10.81 +/- 3.70; group 3: 13.51 +/- 3.21; group 4: 14.79 +/- 3.76; group 5: 15.47 +/- 4.07. An analysis of variance showed that the results in groups 1, 4 and 5 were not significantly different but that the bond strengths in groups 2 and 3 were significantly lower. Fracture within the enamel occurred in 8 specimens in group 1, 5 in group 2, 6 in group 3, 8 in group 4, and 13 in group 5. In the fluoridated etchant groups the number of specimens showing enamel fracture increased as the application time of the etchant increased.

Human group II phospholipase A2. Characterization of monoclonal antibodies and immunochemical quantitation of the protein in synovial fluid

Murine monoclonal and rabbit polyclonal antibodies were generated against human group II phospholipase A2 (PLA2) in order to study the role of this enzyme in inflammatory disease, the source of its synthesis, and the interaction of PLA2 with its substrate. Monoclonal antibody PLA187 exhibits potent inhibitory activity toward human PLA2 using autoclaved E. coli membranes as the substrate. Three other monoclonal antibodies (PLA184, PLA185, and PLA186) also inhibit enzyme activity, but with about 50-fold less potency. Based on the results of double-antibody competition experiments and enzyme inhibition profiles, PLA184 and PLA185 appear to recognize the same epitope. Monoclonal antibody PLA186 recognizes an epitope which is spatially distinct from that recognized by PLA184/185. The results also suggest that the epitope recognized by PLA187 may overlap with both epitopes recognized by PLA186 and PLA184/185. A double-antibody sandwich ELISA was developed using a combination of PLA185 and rabbit polyclonal antibody against PLA2. The ELISA provides a sensitive and quantitative method for monitoring specifically group II PLA2 in various biological sources, independent of factors which may affect enzyme activity. We have utilized this assay to quantitate PLA2 levels in synovial fluid from the joints of individuals with rheumatoid arthritis as well as from non-arthritic joints. Our results indicate that elevated levels of group II PLA2 in synovial fluid are not necessarily associated with arthritis.

Effect of a triclosan/copolymer/fluoride dentifrice prophylaxis on the shear bond strength of a composite resin to enamel

A new fluoride dentifrice formulation containing triclosan and a copolymer has been introduced. The purpose of this study was to evaluate the shear bond strength of a resin composite bonded to enamel previously cleaned with this new dentifrice formulation. A total of 45 human extracted permanent molars were used. A flat enamel surface was obtained with 600 grit SiC paper and the teeth randomly distributed into 3 groups of 15 teeth each: Group 1: Pumice prophylaxis with a rubber cup and slow-speed handpiece; Group 2: Prophylaxis with a conventional fluoridated dentifrice (Colgate); Group 3: Prophylaxis with a triclosan/copolymer/NaF dentifrice (Colgate). After prophylaxis, the teeth were acid-etched with a 37% phosphoric acid gel for 30 seconds, rinsed and dried. An unfilled resin (Coe Bond) was thinly applied with a brush and cured for 30 seconds. A nylon ring was placed over the area and filled with a light-cured resin composite (Occlusin). The teeth were thermocycled for 100 cycles, mounted in plastic cups and plaster, and sheared with a knife-edged blade in an Instron running at a crosshead speed of 1 mm/min. The results in MPa were as follows: Group 1: 11.34 +/- 4.57; Group 2: 13.46 +/- 3.60; Group 3: 13.84 +/- 4.33. An ANOVA showed that there was no statistically significant difference among the groups. Fracture within the enamel occurred in 27% in Group 1, 47% in Group 2, and 67% in Group 3. The results support the use of the fluoride dentifrices tested in this study for prophylaxis prior to bonding procedures.

Establishment and evaluation of a serum cholesterol monitoring service in a community pharmacy

A clinical pharmacy service providing blood cholesterol testing and consultation was implemented in a community pharmacy. In this pilot study, 27 patients each paid $10 to have a serum cholesterol determination. All subjects completed a questionnaire to determine attitude toward such a service, intention to use it in the future, and willingness to pay for its use. A posttest patient satisfaction questionnaire was completed after blood-level results were reported and discussed with the patient. All subjects stated that they were strongly in favor of such a service, that they would use it, and that they would pay an average of $11.60 for the test. On the posttest questionnaire, patients expressed strong satisfaction with various aspects of the service, and the amount that they were willing to pay increased significantly to $14.35. It is recommended that community pharmacies implement such patient-oriented services.

TONAR calibration: a brief note

Measurements were made of the frequency response characteristics of the microphone-separator components of TONAR II instrumentation. The results of our calibration studies revealed 1) appreciable non-uniformity in frequency response of the two microphones, 2) a considerable degree of mismatch in frequency response between the microphones and, 3) dynamic interactions among microphone, separator cavity, and talker cavity resonant characteristics. Findings are discussed in terms of their implications regarding the validity of TONAR II based nasalance ratio measures.

Repressible alkaline phosphatase from Thermus aquaticus: associated phosphodiesterase activity

A repressible alkaline phosphatase has been isolated from the extreme bacterial thermophile. Thermus aquaticus, and has been purified to homogeneity as judged by disc acrylamide electrophoresis and sodium dodecyl sulfate electrophoresis. Upon investigation, the purified enzyme was shown to hydrolyze certain phosphodiesters in addition to a wide variety of phosphomonoesters. The diesters included bis-p-nitro-phenyl phosphate and thymidine 3'-monophospho-p-nitro-phenyl ester. The temperature optimum for the diesterase activity was 80--85 degrees at pH 7.2. Orthophosphate competitively inhibited both activities. Nucleotides such as AMP, ADP, and ATP also inhibited both esterase activities as did alpha-D-glucose 1-phosphate and alpha-sodium glycerol phosphate. The isoelectric point of the enzyme was determined to be 8.4.

Glucose metabolism in thyroidectomized and normal dogs during rest and acute cold exposure

Uniformly labeled (14C)glucose was infused iv at a constant rate into unanesthetized surgically thyroidectomized (THY) and normal dogs during the basal state at 22 degrees C and during cold exposure at 4-5 degrees C. 02 uptake, CO2 output, and plasma glucose levels were determined; from these rates of glucose turnover and oxidation were calculated. Comparison of THY with normal dogs shows that at a mean plasma glucose level of 103 mg/100 ml, a significantly lower glucose turnover rate was observed in THY dogs on the basis of a kg body weight, body surface area (m-2), but not per cal BMR. The same percentage of glucose turnover was immediately oxidized in THY and normal dogs, accounting for 16 and 15% of the total caloric expenditure, respectively. Acute cold exposure increased energy expenditure in both THY and normal dogs without a change in glucose level or turnover rate. However, the percentage of glucose turnover which was immediately oxidized as well as the amount of glucose oxidized increased significantly and proportionally to the increase in energy expenditure so that the percent of calories derived from plasma glucose oxidation remained the same as that observed during the control period.