Crowdsourcing digital health measures to predict Parkinson's disease severity: the Parkinson's Disease Digital Biomarker DREAM Challenge

Consumer wearables and sensors are a rich source of data about patients' daily disease and symptom burden, particularly in the case of movement disorders like Parkinson's disease (PD). However, interpreting these complex data into so-called digital biomarkers requires complicated analytical approaches, and validating these biomarkers requires sufficient data and unbiased evaluation methods. Here we describe the use of crowdsourcing to specifically evaluate and benchmark features derived from accelerometer and gyroscope data in two different datasets to predict the presence of PD and severity of three PD symptoms: tremor, dyskinesia, and bradykinesia. Forty teams from around the world submitted features, and achieved drastically improved predictive performance for PD status (best AUROC = 0.87), as well as tremor- (best AUPR = 0.75), dyskinesia- (best AUPR = 0.48) and bradykinesia-severity (best AUPR = 0.95).

Limb and trunk accelerometer data collected with wearable sensors from subjects with Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor and non-motor symptoms. Dyskinesia and motor fluctuations are complications of PD medications. An objective measure of on/off time with/without dyskinesia has been sought for some time because it would facilitate the titration of medications. The objective of the dataset herein presented is to assess if wearable sensor data can be used to generate accurate estimates of limb-specific symptom severity. Nineteen subjects with PD experiencing motor fluctuations were asked to wear a total of five wearable sensors on both forearms and shanks, as well as on the lower back. Accelerometer data was collected for four days, including two laboratory visits lasting 3 to 4 hours each while the remainder of the time was spent at home and in the community. During the laboratory visits, subjects performed a battery of motor tasks while clinicians rated limb-specific symptom severity. At home, subjects were instructed to use a smartphone app that guided the periodic performance of a set of motor tasks.

Accelerometer data collected with a minimum set of wearable sensors from subjects with Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder associated with motor and non-motor symptoms. Current treatments primarily focus on managing motor symptom severity such as tremor, bradykinesia, and rigidity. However, as the disease progresses, treatment side-effects can emerge such as on/off periods and dyskinesia. The objective of the Levodopa Response Study was to identify whether wearable sensor data can be used to objectively quantify symptom severity in individuals with PD exhibiting motor fluctuations. Thirty-one subjects with PD were recruited from 2 sites to participate in a 4-day study. Data was collected using 2 wrist-worn accelerometers and a waist-worn smartphone. During Days 1 and 4, a portion of the data was collected in the laboratory while subjects performed a battery of motor tasks as clinicians rated symptom severity. The remaining of the recordings were performed in the home and community settings. To our knowledge, this is the first dataset collected using wearable accelerometers with specific focus on individuals with PD experiencing motor fluctuations that is made available via an open data repository.

Design of a virtual longitudinal observational study in Parkinson's disease (AT-HOME PD)

OBJECTIVE

The expanding power and accessibility of personal technology provide an opportunity to reduce burdens and costs of traditional clinical site-centric therapeutic trials in Parkinson's disease and generate novel insights. The value of this approach has never been more evident than during the current COVID-19 pandemic. We sought to (1) establish and implement the infrastructure for longitudinal, virtual follow-up of clinical trial participants, (2) compare changes in smartphone-based assessments, online patient-reported outcomes, and remote expert assessments, and (3) explore novel digital markers of Parkinson's disease disability and progression.

METHODS

Participants from two recently completed phase III clinical trials of inosine and isradipine enrolled in Assessing Tele-Health Outcomes in Multiyear Extensions of Parkinson's Disease trials (AT-HOME PD), a two-year virtual cohort study. After providing electronic informed consent, individuals complete annual video visits with a movement disorder specialist, smartphone-based assessments of motor function and socialization, and patient-reported outcomes online.

RESULTS

From the two clinical trials, 226 individuals from 42 states in the United States and Canada enrolled. Of these, 181 (80%) have successfully downloaded the study's smartphone application and 161 (71%) have completed patient-reported outcomes on the online platform.

INTERPRETATION

It is feasible to conduct a large-scale, international virtual observational study following the completion of participation in brick-and-mortar clinical trials in Parkinson's disease. This study, which brings research to participants, will compare established clinical endpoints with novel digital biomarkers and thereby inform the longitudinal follow-up of clinical trial participants and design of future clinical trials.

Meta-Analysis of the Alzheimer's Disease Human Brain Transcriptome and Functional Dissection in Mouse Models

We present a consensus atlas of the human brain transcriptome in Alzheimer's disease (AD), based on meta-analysis of differential gene expression in 2,114 postmortem samples. We discover 30 brain coexpression modules from seven regions as the major source of AD transcriptional perturbations. We next examine overlap with 251 brain differentially expressed gene sets from mouse models of AD and other neurodegenerative disorders. Human-mouse overlaps highlight responses to amyloid versus tau pathology and reveal age- and sex-dependent expression signatures for disease progression. Human coexpression modules enriched for neuronal and/or microglial genes broadly overlap with mouse models of AD, Huntington's disease, amyotrophic lateral sclerosis, and aging. Other human coexpression modules, including those implicated in proteostasis, are not activated in AD models but rather following other, unexpected genetic manipulations. Our results comprise a cross-species resource, highlighting transcriptional networks altered by human brain pathophysiology and identifying correspondences with mouse models for AD preclinical studies.

Indicators of retention in remote digital health studies: a cross-study evaluation of 100,000 participants

Digital technologies such as smartphones are transforming the way scientists conduct biomedical research. Several remotely conducted studies have recruited thousands of participants over a span of a few months allowing researchers to collect real-world data at scale and at a fraction of the cost of traditional research. Unfortunately, remote studies have been hampered by substantial participant attrition, calling into question the representativeness of the collected data including generalizability of outcomes. We report the findings regarding recruitment and retention from eight remote digital health studies conducted between 2014-2019 that provided individual-level study-app usage data from more than 100,000 participants completing nearly 3.5 million remote health evaluations over cumulative participation of 850,000 days. Median participant retention across eight studies varied widely from 2-26 days (median across all studies = 5.5 days). Survival analysis revealed several factors significantly associated with increase in participant retention time, including (i) referral by a clinician to the study (increase of 40 days in median retention time); (ii) compensation for participation (increase of 22 days, 1 study); (iii) having the clinical condition of interest in the study (increase of 7 days compared with controls); and (iv) older age (increase of 4 days). Additionally, four distinct patterns of daily app usage behavior were identified by unsupervised clustering, which were also associated with participant demographics. Most studies were not able to recruit a sample that was representative of the race/ethnicity or geographical diversity of the US. Together these findings can help inform recruitment and retention strategies to enable equitable participation of populations in future digital health research.

Detecting the impact of subject characteristics on machine learning-based diagnostic applications

Collection of high-dimensional, longitudinal digital health data has the potential to support a wide-variety of research and clinical applications including diagnostics and longitudinal health tracking. Algorithms that process these data and inform digital diagnostics are typically developed using training and test sets generated from multiple repeated measures collected across a set of individuals. However, the inclusion of repeated measurements is not always appropriately taken into account in the analytical evaluations of predictive performance. The assignment of repeated measurements from each individual to both the training and the test sets ("record-wise" data split) is a common practice and can lead to massive underestimation of the prediction error due to the presence of "identity confounding." In essence, these models learn to identify subjects, in addition to diagnostic signal. Here, we present a method that can be used to effectively calculate the amount of identity confounding learned by classifiers developed using a record-wise data split. By applying this method to several real datasets, we demonstrate that identity confounding is a serious issue in digital health studies and that record-wise data splits for machine learning- based applications need to be avoided.

Extended treatment of Cushing's disease with pasireotide: results from a 2-year, Phase II study

In a previous 15-day, Phase II study of patients with de novo or persistent/recurrent Cushing's disease (core study), treatment with pasireotide 600 μg sc bid reduced urinary free cortisol (UFC) levels in 76% of patients and normalized UFC in 17%. The objective of this study was to evaluate the efficacy and safety of extended treatment with pasireotide. This was a planned, open-ended, single-arm, multicenter extension study (primary endpoint: 6 months). Patients aged ≥18 years with Cushing's disease who completed the core study could enter the extension if they achieved UFC normalization at core study end and/or obtained significant clinical benefit. Of the 38 patients who completed the core study, 19 entered the extension and 18 were included in the efficacy analyses (three responders, 11 reducers, four non-reducers in the core study). At data cut-off, median treatment duration in the extension was 9.7 months (range: 2 months to 4.8 years). At extension month 6, 56% of the 18 patients had lower UFC than at core baseline and 22% had normalized UFC. Of the four patients who remained on study drug at month 24, one had normalized UFC. Reductions in serum cortisol, plasma adrenocorticotropic hormone, body weight and diastolic blood pressure were observed. The most common adverse events were mild-to-moderate gastrointestinal disorders and hyperglycemia. Pasireotide offers a tumor-directed medical therapy that may be effective for the extended treatment of some patients with Cushing's disease.

Observation of edge instability limiting the pedestal growth in tokamak plasmas

With fusion device performance hinging on the edge pedestal pressure, it is imperative to experimentally understand the physical mechanism dictating the pedestal characteristics and to validate and improve pedestal predictive models. This Letter reports direct evidence of density and magnetic fluctuations showing the stiff onset of an edge instability leading to the saturation of the pedestal on the Alcator C-Mod tokamak. Edge stability analyses indicate that the pedestal is unstable to both ballooning mode and kinetic ballooning mode in agreement with observations.

Preclinical trials in autosomal dominant AD: implementation of the DIAN-TU trial

The Dominantly Inherited Alzheimer's Network Trials Unit (DIAN-TU) was formed to direct the design and management of interventional therapeutic trials of international DIAN and autosomal dominant Alzheimer's disease (ADAD) participants. The goal of the DIAN-TU is to implement safe trials that have the highest likelihood of success while advancing scientific understanding of these diseases and clinical effects of proposed therapies. The DIAN-TU has launched a trial design that leverages the existing infrastructure of the ongoing DIAN observational study, takes advantage of a variety of drug targets, incorporates the latest results of biomarker and cognitive data collected during the observational study, and implements biomarkers measuring Alzheimer's disease (AD) biological processes to improve the efficiency of trial design. The DIAN-TU trial design is unique due to the sophisticated design of multiple drugs, multiple pharmaceutical partners, academics servings as sponsor, geographic distribution of a rare population and intensive safety and biomarker assessments. The implementation of the operational aspects such as home health research delivery, safety magnetic resonance imagings (MRIs) at remote locations, monitoring clinical and cognitive measures, and regulatory management involving multiple pharmaceutical sponsors of the complex DIAN-TU trial are described.

Increases in dissolved organic carbon accelerate loss of toxic Al in Adirondack lakes recovering from acidification

Increasing pH and decreasing Al in surface waters recovering from acidification have been accompanied by increasing concentrations of dissolved organic carbon (DOC) and associated organic acids that partially offset pH increases and complicate assessments of recovery from acidification. To better understand the processes of recovery, monthly chemistry from 42 lakes in the Adirondack region, NY, collected from 1994 to 2011, were used to (1) evaluate long-term changes in DOC and associated strongly acidic organic acids and (2) use the base-cation surplus (BCS) as a chemical index to assess the effects of increasing DOC concentrations on the Al chemistry of these lakes. Over the study period, the BCS increased (p < 0.01) and concentrations of toxic inorganic monomeric Al (IMAl) decreased (p < 0.01). The decreases in IMAl were greater than expected from the increases in the BCS. Higher DOC concentrations that increased organic complexation of Al resulted in a decrease in the IMAl fraction of total monomeric Al from 57% in 1994 to 23% in 2011. Increasing DOC concentrations have accelerated recovery in terms of decreasing toxic Al beyond that directly accomplished by reducing atmospheric deposition of strong mineral acids.

Treatment of pituitary-dependent Cushing's disease with the multireceptor ligand somatostatin analog pasireotide (SOM230): a multicenter, phase II trial

CONTEXT

There is currently no medical therapy for Cushing's disease that targets the pituitary adenoma. Availability of such a medical therapy would be a valuable therapeutic option for the management of this disorder.

OBJECTIVE

Our objective was to evaluate the short-term efficacy of the novel multireceptor ligand somatostatin analog pasireotide in patients with de novo, persistent, or recurrent Cushing's disease.

DESIGN

We conducted a phase II, proof-of-concept, open-label, single-arm, 15-d multicenter study.

PATIENTS

Thirty-nine patients with either de novo Cushing's disease who were candidates for pituitary surgery or with persistent or recurrent Cushing's disease after surgery without having received prior pituitary irradiation.

INTERVENTION

Patients self-administered sc pasireotide 600 microg twice daily for 15 d.

MAIN OUTCOME MEASURE

Normalization of urinary free cortisol (UFC) levels after 15 d treatment was the main outcome measure.

RESULTS

Of the 29 patients in the primary efficacy analysis, 22 (76%) showed a reduction in UFC levels, of whom five (17%) had normal UFC levels (responders), after 15 d of treatment with pasireotide. Serum cortisol levels and plasma ACTH levels were also reduced. Steady-state plasma concentrations of pasireotide were achieved within 5 d of treatment. Responders appeared to have higher pasireotide exposure than nonresponders.

CONCLUSIONS

Pasireotide produced a decrease in UFC levels in 76% of patients with Cushing's disease during the treatment period of 15 d, with direct effects on ACTH release. These results suggest that pasireotide holds promise as an effective medical treatment for this disorder.

Cognitive deterioration associated with an expedition in an extreme desert environment

BACKGROUND

Prolonged exposure to extreme environments may result in cognitive changes that may influence decision making ability and increasing risk of injury or death.

OBJECTIVE

To measure the cognitive performance of a healthy man as he completed a 17 day desert expedition.

METHOD

A computer based cognitive test battery, subjective cognitive rating scale, and measures of physical characteristics were used. Objective cognitive performance was compared with the performance of eight age matched men who remained in their own homes.

RESULTS

The speed of psychomotor, attentional, and executive functions decreased as the expedition progressed, but the accuracy of performance remained unaffected. Although some impairments were large, they resolved completely once the expedition was completed. Subjective ratings indicated that the subject had insight into his failing cognitive performance during the expedition.

CONCLUSIONS

Cognitive performance can be measured repeatedly throughout an expedition in an extreme environment. Cognitive impairment may occur.

Randomised controlled trial of transcutaneous electrical muscle stimulation of the lower extremities in patients with chronic obstructive pulmonary disease

BACKGROUND

Although exercise training improves exercise tolerance in most patients with chronic obstructive pulmonary disease (COPD), some patients with severe disease may not be able to tolerate exercise training due to incapacitating breathlessness. Transcutaneous electrical muscle stimulation (TCEMS) has been shown to improve muscle strength, muscle mass, and performance in paraplegics, patients with knee ligament injury, and patients with peripheral vascular disease. We hypothesised that TCEMS of the lower extremities can improve muscle strength and exercise tolerance in patients with moderate to severe COPD.

METHODS

A randomised controlled trial of TCEMS of the lower extremities was performed in 18 medically stable patients of mean (SD) age 60.0 (1.5) years with a mean forced expiratory volume in 1 second (FEV(1)) of 1.03 (0.10) l (38% predicted) and residual volume/total lung capacity (RV/TLC) of 59 (2)%. Stimulation of the lower extremities was performed three times a week, 20 minutes each session, for six continuous weeks. Quadriceps and hamstring muscle strength, exercise capacity, and peak oxygen uptake were measured at baseline and after 6 weeks of stimulation.

RESULTS

TCEMS improved both the quadriceps strength (by 39.0 (20.4)% v 9.0 (8.1)%, p=0.046) and hamstring muscle strength (by 33.9 (13.0)% v 2.9 (4.7)%, p=0.038) in the treated (n=9) and sham treated (n=9) groups, respectively. The improvement in muscle strength carried over to better performance in the shuttle walk test in the treated group (36.1% v 1.6% in the treated and sham groups respectively, p=0.007, Mann-Whitney U test). There was no significant change in lung function, peak workload, or peak oxygen consumption in either group. Muscle stimulation was well tolerated by the patients with no dropouts and better than 95% compliance with the protocol.

CONCLUSIONS

TCEMS of peripheral muscles can be a useful adjunct to the comprehensive pulmonary rehabilitation of patients with COPD.

Evaluation of a post-professional master's program in allied health

Changes in allied health education have precipitated a need to review existing educational programs. As more disciplines require a graduate degree for professional entry, it becomes important to articulate the benefits of advanced, post-professional graduate education for allied health professionals. This article reports results from a study of one interdisciplinary Master of Health Sciences (MHS) program. The intent of the study was to 1) analyze graduates' satisfaction with components of the MHS program; 2) explore the perceived impact of the MHS program on graduates' professional practices; and 3) examine employers' perceptions of the program's effect on graduates' professional behaviors. An investigator-developed written questionnaire was used to gather perspectives from 53 graduates and 27 of their employers. Graduates believed the MHS program had had a positive influence on their employment. Graduates' employers concurred, giving high marks to graduates' skill levels and job performances. Program graduates were active in professional organizations, but few were involved in scholarly activities such as research. Implications for curriculum design of advanced master's programs in allied health are discussed.

Quantitative analysis of epithelial cell aggregation in the simple metazoan Hydra reveals a switch from homotypic to heterotypic cell interactions

Hydra, a member of the diploblastic phylum Cnidaria, exhibits the most basic type of organized metazoan tissues. Two unicellular sheets of polarized epithelial cells - ectoderm and endoderm - form a double layer throughout the body column. The double layer can be reestablished from single-cell suspensions by tissue-specific cell-sorting processes. However, the underlying pattern of interactions between ectodermal and endodermal epithelial cells responsible for double-layer formation is unclear. By analyzing cell interactions in a quantitative adhesion assay using mechanically dissociated Hydra epithelial cells, we show that aggregation proceeds in two steps. First, homotypic interactions within ectodermal epithelial cells (ecto-ecto) and within endodermal epithelial cells (endo-endo) form homotypic cell clusters. Second, at an aggregate size of about ten epithelial cells/cluster, ectodermal and endodermal clusters start to form heterotypic aggregates. Homotypic ecto-ecto interactions are inhibited by a polyclonal anti-Hydra membrane antiserum, and under these conditions homotypic endo-endo interactions do not proceed beyond a size of about ten epithelial cells/cluster. These data suggest that homotypic cell clusters reduce their initial homotypic affinity and acquire a new heterotypic affinity. A link between cell adhesion and cell signaling in early Hydra aggregates is discussed.

WNT signalling molecules act in axis formation in the diploblastic metazoan Hydra

Members of the Wnt/wingless family of secreted proteins act as short-range inducers and long-range organizers during axis formation, organogenesis and tumorigenesis in many developing tissues. Wnt signalling pathways are conserved in nematodes, insects and vertebrates. Despite its developmental significance, the evolutionary origin of Wnt signalling is unclear. Here we describe the molecular characterization of members of the Wnt signalling pathway--Wnt, Dishevelled, GSK3, beta-Catenin and Tcf/Lef--in Hydra, a member of the evolutionarily old metazoan phylum Cnidaria. Wnt and Tcf are expressed in the putative Hydra head organizer, the upper part of the hypostome. Wnt, beta-Catenin and Tcf are transcriptionally upregulated when head organizers are established early in bud formation and head regeneration. Wnt and Tcf expression domains also define head organizers created by de novo pattern formation in aggregates. Our results indicate that Wnt signalling may be involved in axis formation in Hydra and support the idea that it was central in the evolution of axial differentiation in early multicellular animals.

Overexpression of the EphA2 tyrosine kinase in prostate cancer

BACKGROUND

Molecules that are highly expressed by human prostate cancers may serve as therapeutically relevant targets or tumor markers. Tyrosine kinases are frequently overexpressed in metastatic tumor cells and this prompted us to screen for tyrosine kinases that are overexpressed in prostate cancer cells.

METHODS

Expression levels of the EphA2 receptor tyrosine kinase were determined by Western blot analysis in canine and human prostate cancer cell lines and in immortalized and transformed variants of 267B1 prostatic epithelial cells. EphA2 levels in benign human prostate and prostate cancers were also determined in formalin-fixed, paraffin-embedded tissues using immunohistochemical staining.

RESULTS

Metastatic prostate cancer cells overexpressed EphA2 by 10-100 fold as compared with non-invasive prostatic epithelial cells. EphA2 immunoreactivity in vivo was also significantly greater in human prostate cancers as compared with benign prostate epithelium.

CONCLUSIONS

The EphA2 receptor tyrosine kinase is differentially expressed in human and canine prostate cancer cell lines and overexpressed in human prostate cancers as compared with benign prostate tissues. Metastasis-derived canine prostate carcinoma cell lines overexpress EphA2 and may provide pre-clinical models to further evaluate the role of EphA2 in prostate carcinogenesis. Further investigations are needed to determine the utility of EphA2 as a tumor marker and a novel target in human prostate cancer.

Process evaluation in a multisite, primary obesity-prevention trial in American Indian schoolchildren

We describe the development, implementation, and use of the process evaluation component of a multisite, primary obesity prevention trial for American Indian schoolchildren. We describe the development and pilot testing of the instruments, provide some examples of the criteria for instrument selection, and provide examples of how process evaluation results were used to document and refine intervention components. The theoretical and applied framework of the process evaluation was based on diffusion theory, social learning theory, and the desire for triangulation of multiple modes of data collection. The primary objectives of the process evaluation were to systematically document the training process, content, and implementation of 4 components of the intervention. The process evaluation was developed and implemented collaboratively so that it met the needs of both the evaluators and those who would be implementing the intervention components. Process evaluation results revealed that observation and structured interviews provided the most informative data; however, these methods were the most expensive and time consuming and required the highest level of skill to undertake. Although the literature is full of idealism regarding the uses of process evaluation for formative and summative purposes, in reality, many persons are sensitive to having their work evaluated in such an in-depth, context-based manner as is described. For this reason, use of structured, quantitative, highly objective tools may be more effective than qualitative methods, which appear to be more dependent on the skills and biases of the researcher and the context in which they are used.

Pathways: a culturally appropriate obesity-prevention program for American Indian schoolchildren

Pathways, a culturally appropriate obesity prevention study for third-, fourth-, and fifth-grade American Indian schoolchildren includes an intervention that promotes increased physical activity and healthful eating behaviors. The Pathways intervention, developed through a collaboration of universities and American Indian nations, schools, and families, focuses on individual, behavioral, and environmental factors and merges constructs from social learning theory with American Indian customs and practices. We describe the Pathways program developed during 3 y of feasibility testing in American Indian schools, with special emphasis on the activities developed for the third grade; review the theoretical and cultural underpinnings of the program; outline the construction process of the intervention; detail the curriculum and physical education components of the intervention; and summarize the formative assessment and the school food service and family components of the intervention.

The Pathways study: a model for lowering the fat in school meals

We describe the development and implementation of the Pathways school food service intervention during the feasibility phase of the Pathways study. The purpose of the intervention was to lower the amount of fat in school meals to 30% of energy to promote obesity prevention in third- through fifth-grade students. The Pathways nutrition staff and the food service intervention staff worked together to develop 5 interrelated components to implement the intervention. These components were nutrient guidelines, 8 skill-building behavioral guidelines, hands-on materials, twice yearly trainings, and monthly visits to the kitchens by the Pathways nutrition staff. The components were developed and implemented over 18 mo in a pilot intervention in 4 schools. The results of an initial process evaluation showed that 3 of the 4 schools had implemented 6 of the 8 behavioral guidelines. In an analysis of 5 d of school menus from 3 control schools, the lunch menus averaged from 34% to 40% of energy from fat; when the menus were analyzed by using the food preparation and serving methods in the behavioral guidelines, they averaged 31% of energy from total fat. This unique approach of 5 interrelated food service intervention components was accepted in the schools and is now being implemented in the full-scale phase of the Pathways study in 40 schools for 5 y.

Effects of human intravenous immunoglobulin on canine monocytes and lymphocytes

OBJECTIVE

To evaluate interactions of human intravenous immunoglobulin (IVIG) with canine lymphocytes and monocytes.

SAMPLE POPULATION

Heparinized blood samples from 4 clinically normal Beagles.

PROCEDURE

Binding ability of IVIG to canine lymphocytes and monocytes was measured by flow cytometry and an indirect immunofluorescent assay. Dual-staining fluorescent assays were done to determine lymphocyte subsets that bind IVIG. Competitive assays were done, using intact canine IgG and Fc fragments, and inhibition of binding was compared with that of F(ab)2 fragments. Ability of IVIG to inhibit phagocytosis of antibody-coated canine RBC also was determined, using a canine mononuclear cell phagocytic assay.

RESULTS

IVIG concentrations (10, 1, 0.1, and 0.01 mg/ml) bound to (mean+/-SD) 99.6+/-0.4, 92.4+/-6.1, 20.4+/-24.6 and 2.0+/-5.1 % of canine lymphocytes, respectively, Dual staining analyses with IVIG and canine lymphocyte markers indicated that IVIG bound to CD4, CD8, and B lymphocytes. The aforementioned 4 IVIG concentrations bound to 98.0+/-2.1, 85.5+/-13.5, 64.7+/-32.8, and 26.5+/-17.1 % of monocytes, respectively. Inhibition of IVIG (0.01 mg/ml) binding to monocytes was significant (P< 0.05) in the presence of 1 and 10 mg of canine IgG/ml and 1 mg of canine Fc fragments/ml. In the presence of F(ab')2 fragments of canine IgG, inhibition was not significant, suggesting that binding is Fc mediated. Co-culturing of monocytes, opsonized RBC, and the 4 concentrations of IVIG and no IVIG resulted in 11.8+/-5.1, 27.7+/-12.3, 31.8+15.1, 53.8+/-6.7, and 45 + 12% of the monocytes containing RBC, respectively. Phagocytosis inhibition was significant (P < 0.05) at an IVIG concentration of 10 mg/ml.

CONCLUSIONS

IVIG binds to canine lymphocytes and monocytes; binding to the latter is Fc mediated. IVIG also inhibits Fc-mediated phagocytosis of antibody-coated RBC.

CLINICAL RELEVANCE

Owing to its ability to inhibit Fc-mediated phagocytosis of antibody-coated RBC, IVIG may be an effective short-term treatment for dogs with immune-mediated hemolytic anemia.

Octreotide as primary therapy for acromegaly

The effects of octreotide (up to 5 yr) as primary treatment in 26 patients with acromegaly were compared with those in 81 patients with acromegaly who received octreotide as secondary or adjunctive therapy after previous surgery and/or pituitary radiation. These patients were part of a multicenter study that took place between 1989-1995. The study was divided into 3 phases beginning with a 1-month placebo-controlled treatment period followed by a 1-month washout period. In the second phase, patients were randomized to treatment with either 100 or 250 micrograms octreotide, sc, every 8 h for 6 months. Octreotide was then discontinued for 1 month and reinitiated at the lower dose for a total mean treatment duration of 39 months. The dose was titrated by each investigator to improve each patient's individual response, which included improvement in symptoms and signs of acromegaly as well as reduction of GH and insulin-like growth factor I (IGF-I) into the normal range. In the second phase of the study, in which patients were randomized to either 100 or 250 micrograms octreotide, three times daily, mean integrated GH and IGF-I concentrations after 3 and 6 months were equivalent in the primary and secondary treatment groups. During long term open label treatment, mean GH fell from 32.7 +/- 5.2 to 6.0 +/- 1.7 micrograms/L 2 h after octreotide injection in the primary therapy group and remained suppressed for a mean period of 24 months (range, 3-60 months). The mean final daily dose was 777 micrograms. In the patients receiving secondary treatment, mean GH fell from 30.2 +/- 7.6 to 5.6 +/- 1.1 micrograms/L after 3 months and remained suppressed for the remainder of the study (average dose, 635 micrograms daily). Mean IGF-I concentrations fell from 5.2 +/- 0.5 x 10(3) U/L (primary treatment group) and 4.7 +/- 0.4 x 10(3) U/L (secondary treatment group) to a mean of 2.2 +/- 0.3 x 10(3) U/L in both groups after 3 months of open label treatment and remained suppressed. IGF-I was reduced into the normal range during at least half of the study visits in 68% of the primary treatment group and in 62% of the secondary treatment group. Patients whose GH levels fell to at least 2 SD below the baseline mean GH were considered responders. There was no significant difference in the percentage of responders in the primary and secondary treatment groups (70% vs. 61%), nor was there a statistical difference in the mean GH concentrations between the groups. Symptoms of headache, increased perspiration, fatigue, and joint pain were reported at baseline by 46%, 73%, 69%, and 85%, respectively, of patients in the primary therapy group and improved during 3 yr of octreotide treatment in 50-100%. Similarly, these acromegaly-related symptoms were reported by 62%, 58%, 78%, and 60% of patients in the secondary therapy group, and improvement was noted in 62-88%. Pituitary magnetic resonance imaging scans were available in 13 of 26 patients in the primary treatment group before and after 6 months of octreotide treatment. Tumor shrinkage was observed in 6 of 13 patients, with reduction in tumor volume greater than 25% in only 3. Of 6 patients with documented tumor shrinkage, IGF-I was reduced into the normal range in 4 patients. Of the 7 remaining patients in whom tumor shrinkage was less than 10%, IGF-I was reduced into the normal range in 4 patients. Of the 7 remaining patients in whom tumor shrinkage was less than 10%, IGF-I was reduced into the normal range in 5 patients. The degree of tumor shrinkage did not correlate with the percent reduction in IGF-I or GH. In summary, octreotide was equally effective in 26 previously untreated acromegalic patients (primary treatment group) and 81 patients previously treated with either surgery or pituitary radiation (secondary treatment group). These observations call into question the current practice of surgical resection of all newly diagnosed GH-secreting pituitary adenomas regardless of the likelihood of cure. (AB

Impact of fat reduction on micronutrient density of children's diets: the CATCH Study

BACKGROUND

The purpose of this study was to examine the impact of fat reduction on vitamin and mineral density in the diets of groups of children who participated in the CATCH school-based intervention study for 2 1/2 years.

METHODS

Twenty-four-hour dietary recalls were collected on 1,182 children residing in four states and with diverse ethnic backgrounds, at baseline when they were in third grade and again at follow-up when they were in fifth grade.

RESULTS

With a 2.4% reduction in total fat intake from baseline levels in the intervention group, mean changes in vitamin and mineral intakes per 1,000 kcal of this group were small yet significant compared with the control group. As mean fat intake decreased, the nutrient density of most vitamins and minerals increased; the sole exceptions were vitamin E and sodium. Mean intake of all vitamins and minerals studied exceeded 2/3 of the RDA at both baseline and follow- up for both the intervention and the control groups. No significant differences were noted between treatment groups for the percentages of children meeting 2/3 or more of the RDA at both baseline and follow-up periods.

CONCLUSIONS

CATCH was successful in maintaining mean vitamin and mineral intakes of intervention group children when total dietary fat was reduced.

The contributions of proprioceptive deficits, muscle function, and anatomic laxity to functional instability of the ankle

Functional instability is a common complication following an acute ankle sprain. Three potential contributing factors underlying the ankle which chronically gives way are proprioceptive deficits, muscle weakness, and ligamentous laxity. This study's purpose was to document the presence or absence of these concerns in a sample of subjects with unilateral functional ankle instability. Both ankles of 42 subjects were randomly assessed for passive movement sense into inversion and generation of peak torque by the evertors isokinetically. Thirty-four subjects were available for documentation of talar tilt of both ankles through inversion stress radiographs. Analysis found significantly greater mean values for passive movement sense and talar tilt for the involved ankles compared with the uninvolved, while no significant strength differences in peak torque of the evertors were present. Fifty-eight percent of the sample demonstrated clinical impairments in at least one of these three categories. In conclusion, deficits in passive movement sense and anatomic stability are greater concerns than strength deficits when managing the ankle with functional instability.

Transurethral electrical bladder stimulation: a followup report

Transurethral electrical bladder stimulation (TEBS) initially proposed to rehabilitate the neurogenic bladder has been promoted in the United States since the mid 1980s. The ultimate goal of TEBS is volitional voiding. Since January 1989 we performed 938 sessions of stimulation comprising 64 TEBS series in 25 patients with neurogenic bladders. A cystometrogram was performed before each series of stimulation to monitor progress, and at the time of this review parental impressions of the stimulation were obtained by a telephone interview questionnaire. The initial evaluation cystometrogram before stimulation revealed that 18 patients (72%) had bladder contractions. After TEBS 24 patients (96%) manifest contractions. Before stimulation only 3 children sensed the contractions, while during stimulation half of the patients perceived the contractions. A cystometrogram performed before each series demonstrated a greater than 20% increase in the age adjusted bladder capacity in 6 of the 18 patients (33%) with serial studies. Improvements in the end filling pressure defined by clinically significant decreases were observed in 5 of these patients (28%). Results of the telephone questionnaire revealed that the parents perceived a benefit from stimulation more often than the urodynamic studies could confirm. In our experience TEBS is a time-consuming, labor intensive technique. The limited urodynamic benefits our patients achieved have not materially altered the daily voiding regimen and, because of these factors, we are not enrolling any new patients in our TEBS program.

Characterization of translational frame exception patients in Duchenne/Becker muscular dystrophy

The clinical progression of Duchenne muscular dystrophy (DMD) patients with deletions can be predicted in 93% of cases by whether the deletion maintains or disrupts the translational reading frame (frameshift hypothesis). We have identified and studied a number of patients who have deletions that do not conform to the translational frame hypothesis. The most common exception to the frameshift hypothesis is the deletion of exons 3 to 7 which disrupts the translational reading frame. We identified a Becker muscular dystrophy (BMD) patient, an intermediate, and a DMD patient with this deletion. In all three cases, dystrophin was detected and localized to the membrane. One DMD patient with an inframe deletion of exons 4-18 produced no dystrophin. One patient with a mild intermediate phenotype and a deletion of exon 45, which shifts the reading frame, produced no dystrophin. Two patients with large inframe deletions had discordant phenotypes (exons 3-41, DMD; exons 13-48, BMD), but both produced dystrophin that localized to the sarcolemma. The DMD patient, 113, indicates that dystrophin with an intact carboxy terminus can be produced in Duchenne patients at levels equivalent to some Beckers. The dystrophin analysis from these patients, together with patients reported in the literature, indicate that more than one domain can localize dystrophin to the sarcolemma. Lastly, the data shows that although most patients show correlation of clinical severity to molecular data, there are rare patients which do not conform.

Kennedy's disease: a clinicopathologic correlation with mutations in the androgen receptor gene

We confirmed a mutation of the androgen receptor gene as the cause for Kennedy's disease, also called "X-linked recessive spinal and bulbar muscular atrophy" or "bulbospinal neuronopathy." The mutation is characterized by an increased size of a polymorphic tandem CAG repeat within the first exon of the gene. The study population consisted of 17 patients from seven families (five distinct kinships and two isolated cases). Two patients were as yet asymptomatic and had normal examinations. Four carrier females showed the mutant as well as the normal allele; none showed clinical features of Kennedy's disease. There was no large expansion of the mutation observed in three generations of one family. Phenotypic expression between and within families was variable and not related to the size of the mutation. This contrasts with the gene mutations found in myotonic dystrophy and fragile X syndrome, where increased severity of disease correlates with the number of tandem triplet repeats. The findings reported here appear to explain the failure to find genetic anticipation in Kennedy's disease. The DNA test for Kennedy's disease can now be used for definitive diagnosis and carrier detection. In addition, mutation analysis allows early detection, which has implications for potential treatment.

Use of triple-lumen subclavian catheters for administration of total parenteral nutrition

This study evaluated the safety of triple vs single-lumen catheters in intravenous nutrition. Patients who were judged likely to benefit from a triple-lumen catheter were randomized to receive either a single-lumen catheter, with additional peripheral or central venous access as needed, or a triple-lumen catheter. All patients were at increased risk of catheter-related infection because of one or more of the following conditions: > 60 years of age, breakdown of skin integrity, severe underlying illness, diagnosis of acute pancreatitis, recent head or neck surgery, or presence of a preexisting infection. Patients were excluded who had neutropenia, were immunosuppressed, had body burns > 40%, or had contaminated wounds in the subclavicular area. Of 204 patients entered between June 1989 and November 1991, 177 completed the required > or = 7 days of therapy. Seventy-eight of these patients were randomized to a single-lumen catheter and 99 to a triple-lumen catheter. Catheters were inserted and maintained by the Nutrition Support Team. Dressings were monitored daily and changed weekly using a bio-occlusive dressing. When parameters were met for a possible septic episode, simultaneous peripheral and central catheter blood cultures were obtained using the Isolator method. Catheter-related sepsis was considered present if the colony count from a central catheter lumen was > or = 5 times that of the peripheral blood. The incidence of catheter-related sepsis for single-lumen catheters was 2.6% (2 of 78) compared with 13.1% for triple-lumen catheters (13 of 99) (p < .01). No correlation was found with the number of insertion attempts, catheter days, or patient's age.(ABSTRACT TRUNCATED AT 250 WORDS)

Transurethral electrical bladder stimulation: initial results

Transurethral electrical bladder stimulation to rehabilitate the neurogenic bladder initially proposed by Katona has been promoted in the United States by Kaplan and Richards since the mid 1980s. Encouraged by their results, 2 1/2 years ago we instituted a program patterned on their experience. Since January 1989 we performed transurethral electrical bladder stimulation in 21 patients ranging in age from 4 months to 26 years. The cause of the neurogenic bladder was myelomeningocele in 16 patients, lipomeningocele in 4 and an incomplete spinal cord injury in 1. The stimulation was performed using equipment supplied by Kaplan and Richards, and the stimulation protocol followed their recommendations. The treatments were delivered in daily sessions of 90 minutes with about 20 sessions in a series. Of the patients 11 have undergone 1,6 have finished 2 and 4 have completed 3 series of stimulation. The ultimate objective of the program is to achieve volitional voiding. To reach that goal the stimulation must engender a bladder contraction that must then be perceived and ultimately controlled. Of our patients 20 (95%) achieved bladder contractions during stimulation, including 12 (60%) who had either a definite (7) or probable (5) sense of these contractions. To date, only 1 patient has started the biofeedback program to attempt to modify detrusor activity and he is presently wet on clean intermittent catheterization. Parents of 5 other children report minor positive changes in the child's perception of the bladder activity. Three patients noticed an improvement in the bowel program, although the effect only lasted during the month of stimulation in 1. Cystometrograms were performed before each series of treatments. Of the 10 patients with serial studies 2 had significant increases in bladder capacity and 3 demonstrated a clinically significant decrease in the end filling pressures. We have seen limited encouraging results from transurethral electrical bladder stimulation. This is a time-consuming, labor intensive program, and the parents and patients need to be informed of the actual potential for dramatic improvements.

Terbutaline and diaphragm function in chronic obstructive pulmonary disease: a double-blind randomized clinical trial

We conducted a double-blind, randomized crossover trial to evaluate whether oral terbutaline (2.5 mg orally three times daily for a week) increased the force of diaphragmatic contraction in normocapnic patients with chronic obstructive pulmonary disease. Ten patients with moderate to severe airway obstruction completed the trail. Compared with placebo, terbutaline produced a mean increase of 5.8 cmH2O in peak inspiratory mouth pressure and a mean increase of 5.0 cmH2O in transdiaphragmatic pressure during a maximal inspiratory manoeuvre. These small changes with terbutaline failed to achieve statistical significance. Also, terbutaline failed to alter flow rates (FEV1, Vmax50) or patients' dyspnoea ratings using two separate clinical scales (Pneumoconiosis Research Unit Score and the Modified Dyspnoea Index). Because all observed changes in respiratory muscle strength were small and because the trial had power to detect small changes in inspiratory mouth pressures, we suggest that oral terbutaline at the dose administered in this study has little noteworthy effect on respiratory muscle strength in normocapnic patients with chronic obstructive pulmonary disease.

In vitro production of anti-influenza virus antibody after simultaneous administration of H3N2 and H1N1 cold-adapted vaccines in seronegative children

Sixteen doubly seronegative (H3N2 and H1N1) young children were recently enrolled in a study of live, attenuated cold-adapted influenza A vaccines. Twelve children received simultaneously H3N2 and H1N1 live, attenuated influenza vaccine intranasally and four received saline as placebo controls. Peripheral blood lymphocytes (PBL) were obtained sequentially from all children and the in vitro production of anti-influenza H3N2 and H1N1 antibody from unstimulated and influenza stimulated cells was measured by ELISA. In vitro antibody studies were performed at 0, 2, 4, and 12 weeks after immunization. PBL from six of 12 children spontaneously produced H3N2 antibody and eleven of 12 produced H1N1 antibody. Influenza stimulation of PBL induced antibody production in 8/12 for H3N2 and 12/12 for H1N1. PBL from all four placebo immunized children failed to produce specific influenza antibody in vitro at any time studied. In vitro antibody produced after immunization was primarily of the IgG isotype with peak production occurring at 4-12 weeks, supporting the primary nature of the response. The correlation between the presence of positive serum HAI and ELISA titres, and the production of in vitro antibody was good for both H3N2 and H1N1 vaccines. In summary, the simultaneous administration of two attenuated influenza A vaccines into the upper respiratory tract of seronegative children resulted in the stimulation of PBL capable of secreting both H3N2 and H1N1 influenza specific antibody in vitro.

Acute effects of passive smoking on lung function and airway reactivity in asthmatic subjects

We studied the acute effects of one hour of passive cigarette smoking on the lung function and airway reactivity of nine young adult asthmatic volunteers. At the time of this study, the subjects were asymptomatic and had normal or nearly normal lung function. Passive smoking produced no change in expiratory flow rates. However, there was a small decrease in nonspecific bronchial reactivity, as assessed by methacholine inhalation challenge testing (p = 0.022). Pharmacologically active substances present in cigarette smoke, such as nicotine, may explain the observed change in airway reactivity. Although the finding of decreased airway reactivity might suggest that passive smoking produces a "protective" effect on the underlying asthma, the observed change in reactivity was slight and of uncertain clinical significance. We conclude that passive smoking presents no acute respiratory risk to young asymptomatic asthmatic patients.