Inclusion of Signal Analysis in a Hybrid Medical Decision Support System

Objectives: Signal analysis has played an important role in cardiac diagnosis, both as a separate entity and in conjunction with clinical parameters. Hybrid systems are an effective method for developing higher-order decision models in which biomedical signal data can be incorporated.

Methods: The hybrid system components include a knowledge-based system that utilizes approximate reasoning techniques, a neural network model based on a potential function approach to supervised learning that uses the general class of Cohen orthogonal functions as potential functions, and a signal analysis component that relies on continuous chaotic modeling to produce a degree of variability in the time series. The hybrid system is illustrated in an application for differentiation among different types of dementia.

Results: Application of this method to cardiac diagnosis shows that chaotic parameters alone contribute significantly to correct classification while the addition of clinical parameters increases the sensitivity, specificity, and accuracy. Applications to electroencephalogram analysis indicate that the second-order difference plots display significant differences for the different types of EEG waves identifiable by frequency, both in shape and degree of dispersion. Hence the identification of these waves, and the duration of their occurrence, may provide suitable variables for chaotic analysis.

Conclusions: Results from studies in cardiology demonstrate that using chaotic measures for ECG analysis provide useful information for classification. Sensitivity, specificity, and accuracy are increased if these methods are combined with other clinical parameters in a hybrid system. This approach has been extended to new applications based on EEG analysis combined with other relevant information.

Development of health diagnostics based on personalized medical models

Due to rapid evolution of new technologies the concept of personalized medicine has evolved. Components include molecular biology, proteomics, metabolomic analysis, genetic testing, and molecular medicine for diagnostics. In addition to diagnostics these methods can be used to determine individual susceptibility to diseases and conditions. In conjunction with new diagnostic methods, new therapies can be tailored to the individual. These new technologies present a challenge in terms of the expansion of the medical record as well as the development of new methods for creating disease profiles. This article focuses on a computer-aided support for personalized medicine. Specific approaches are explored that permit automated data analysis for prognosis and treatment based on analysis methods for numeric and pictorial data. Although personalized medicine based on the genome of the patient are occasionally performed, because of the large amount of data new methods are needed to form general disease models as well as specific profiles of the individual patient.

Do cancer centers need to assess quality and outcomes? Introducing a customized ACS-NSQIP for oncology (Onc-NSQIP)

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Background: To identify quality improvement opportunities, hospitals can use ACS NSQIP to compare their risk-adjusted performance to other hospitals. However, Cancer Centers have few opportunities to compare their outcomes to similar hospitals for oncologic operations. Our objective was to develop an oncology-specific version of ACS NSQIP (Onc-NSQIP) and determine whether it could be useful for Cancer Centers.

Methods: From ACS-NSQIP (2006-2009), patients undergoing major colorectal (n=34,858; 221 hospitals) and pancreatic (n=7,667; 65 hospitals) as well as esophageal, gastric, and soft tissue operations for malignancy were identified. Risk-adjusted postoperative outcomes were assessed with regression models adjusting for demographics, comorbidities, and operative procedure. Relative rankings of NCI-designated Comprehensive Cancer Centers in ACS NSQIP among the other ACS NSQIP hospitals were compared.

Results: Cancer Center outcomes varied widely for colorectal and pancreas. For overall colorectal morbidity, Cancer Centers were ranked in the top third (n=4), middle third (n=7), and bottom third (n=10). For colorectal 30-day mortality, Cancer Centers were ranked in the top (n=14), middle (n=3), and bottom third (n=4). For overall pancreatic morbidity, Cancer Centers were ranked in the top (n=5), middle (n=7), and bottom third (n=7). For pancreatic 30-day mortality, Cancer Centers were ranked in the top (n=5), middle (n=6), and bottom third (n=8). Similar results were observed for colorectal and pancreas for DVT/PE, SSI, reoperation, and length of stay. Onc-NSQIP models were comparable to standard ACS NSQIP models. At least some Cancer Centers were statistical outliers for most outcomes (P<0.05). Results were similar for other malignancies.

Conclusions: Cancer Center outcomes varied as much as other ACS NSQIP hospitals, demonstrating need for quality assessment. Without standardized risk-adjusted outcomes comparisons, Cancer Centers cannot accurately assess their outcomes to identify quality improvement targets. ACS NSQIP's new platform allows customization so hospitals can compare surgical oncology-specific risk-adjusted processes and outcomes.

No significant financial relationships to disclose.

Efficiency of oral fluid collection devices in extracting antibodies

INTRODUCTION

To facilitate diagnoses, this study determined the efficacy of commercial oral fluid collection devices for their ability to recover three human immunoglobulin isotypes; immunoglobulin A (IgA), IgG, and IgM.

METHODS

The sandwich enzyme-linked immunosorbent assay was used to determine antibody recovery from the following devices: (i) OraSure oral specimen collection device, (ii) saliva*sampler, (iii) ORALscreen collector, (iv) Dri-Angle, (v) no. 2 cotton roll, (vi) all-gauze sponges device, and (vii) DentaSwabs. For each isotype tested, the recovered eluate was compared with the concentration applied to the device. The performance of each device was determined at various antibody concentrations.

RESULTS

Recovery of IgA from the saliva*sampler, ORALscreen collector, Dri-Angle and cotton roll was comparable to that seeded onto the device. When compared with the seeded IgG concentration, the mean concentration of antibody recovered by each product differed by approximately +/- 9 ng/ml. The average amount of IgM recovered by the cotton roll and all-gauze sponges device was approximately 29 and 39 ng/ml, respectively, less (P < 0.0001) than that seeded on the device. For all isotypes tested, the amount of antibody recovered from the device was dependent on the initial seeding concentration.

CONCLUSION

Collectively, these data suggest that the product used for specimen collection can affect retrieval of antibodies and potentially confound patient diagnosis.

Intelligent agent model for remote support of rural healthcare for the elderly

With the aging population, the number of individuals requiring long-term care is expected to dramatically increase in the next twenty years, placing an increasing burden on healthcare. Many patients are admitted to assisted living facilities at a fairly early stage due to their inability to perform normal daily living activities. The purpose of this study is to determine if the use of technology for both monitoring and intervention can permit elderly patients to remain in their homes for longer periods of time with the benefit of the comfort of familiar surroundings while at the same time reducing the burden on caregivers. In addition, remote access to healthcare can improve monitoring of the patient's physical and mental condition and involve the patient in his or her own care. The home monitoring and intervention system is based on intelligent agent methodology developed by the authors.

Non-linear analysis using continuous chaotic modeling

Recent research in nanotechnology is opening exciting new avenues not only for understanding the human body but also for creating devices that can effectively interact with it to alleviate the effects of disease. These new developments present both challenges and opportunities for adaptation of existing methodologies to create new approaches for analysis and modeling of nanotechnology-based systems. The concept of continuous chaotic modeling presents an avenue for a paradigm shift away from traditional digital computing to take advantage of analog models that are more compatible with biological systems. The theoretical basis of continuous chaotic modeling is summarized, followed by illustrations of applications of this methodology.

The role of networks and artificial intelligence in nanotechnology design and analysis

Techniques with their origins in artificial intelligence have had a great impact on many areas of biomedicine. Expert-based systems have been used to develop computer-assisted decision aids. Neural networks have been used extensively in disease classification and more recently in many bioinformatics applications including genomics and drug design. Network theory in general has proved useful in modeling all aspects of biomedicine from healthcare organizational structure to biochemical pathways. These methods show promise in applications involving nanotechnology both in the design phase and in interpretation of system functioning.

Inclusion of signal analysis in a hybrid medical decision support system

OBJECTIVES

Signal analysis has played an important role in cardiac diagnosis, both as a separate entity and in conjunction with clinical parameters. Hybrid systems are an effective method for developing higher-order decision models in which biomedical signal data can be incorporated.

METHODS

The hybrid system components include a knowledge-based system that utilizes approximate reasoning techniques, a neural network model based on a potential function approach to supervised learning that uses the general class of Cohen orthogonal functions as potential functions, and a signal analysis component that relies on continuous chaotic modeling to produce a degree of variability in the time series. The hybrid system is illustrated in an application for differentiation among different types of dementia.

RESULTS

Application of this method to cardiac diagnosis shows that chaotic parameters alone contribute significantly to correct classification while the addition of clinical parameters increases the sensitivity, specificity, and accuracy. Applications to electroencephalogram analysis indicate that the second-order difference plots display significant differences for the different types of EEG waves identifiable by frequency, both in shape and degree of dispersion. Hence the identification of these waves, and the duration of their occurrence, may provide suitable variables for chaotic analysis.

CONCLUSIONS

Results from studies in cardiology demonstrate that using chaotic measures for ECG analysis provide useful information for classification. Sensitivity, specificity, and accuracy are increased if these methods are combined with other clinical parameters in a hybrid system. This approach has been extended to new applications based on EEG analysis combined with other relevant information.

Residual mercury content and leaching of mercury and silver from used amalgam capsules

OBJECTIVE

The objective of this investigation was to carry out residual mercury (Hg) determinations and toxicity characteristic leaching procedure (TCLP) analysis of used amalgam capsules.

METHODS

For residual Hg analysis, 25 capsules (20 capsules for one brand) from each of 10 different brands of amalgam were analyzed. Total residual Hg levels per capsule were determined using United States Environmental Protection Agency (USEPA) Method 7471. For TCLP analysis, 25 amalgam capsules for each of 10 brands were extracted using a modification of USEPA Method 1311. Hg analysis of the TCLP extracts was done with USEPA Method 7470A. Analysis of silver (Ag) concentrations in the TCLP extract was done with USEPA Method 6010B.

RESULTS

Analysis of the residual Hg data resulted in the segregation of brands into three groups: Dispersalloy capsules, Group A, retained the most Hg (1.225 mg/capsule). These capsules were the only ones to include a pestle. Group B capsules, Valliant PhD, Optaloy II, Megalloy and Valliant Snap Set, retained the next highest amount of Hg (0.534-0.770 mg/capsule), and were characterized by a groove in the inside of the capsule. Group C, Tytin regular set double-spill, Tytin FC, Contour, Sybraloy regular set, and Tytin regular set single-spill retained the least amount of Hg (0.125-0.266 mg/capsule). TCLP analysis of the triturated capsules showed Sybraloy and Contour leached Hg at greater than the 0.2 mg/l Resource Conservation and Recovery Act (RCRA) limit.

SIGNIFICANCE

This study demonstrated that residual mercury may be related to capsule design features and that TCLP extracts from these capsules could, in some brands, exceed RCRA Hg limits, making their disposal problematic. At current RCRA limits, the leaching of Ag is not a problem.

The use of consequential reasoning in cancer chemotherapy

Knowledge-based decision support systems traditionally rely on condition-action rule structures, an adequate representation for simple decisions. In complex domains an important part of decision-making includes analysis of the consequences of a decision. Consequential reasoning is particularly important in medicine as potential risk and/or benefit can be included. In this paper, a knowledge structure and inference engine is described that permits the representation and analysis of consequential reasoning in a computer-assisted decision support system. The use of consequential reasoning is then illustrated in an application designed to assist in cancer chemotherapy decisions. The result is a method that is sensitive to individual patient reactions to chemotherapy agents, permitting an individualized approach to therapy. Individualized drug therapy is becoming increasingly feasible due to advances made in the field of genomics. The system is structured so that new information can be incorporated easily. Although the application shown here is to chemotherapy, the general methodology can be used in any area in which the consequences should significantly influence the decision.

Prediction of bile duct stones and complications in gallstone pancreatitis using early laboratory trends

OBJECTIVES

We aimed to determine whether early trends in the serum pancreatic enzymes and liver tests of patients with gallstone pancreatitis predict persistent common bile duct (CBD) stones and complications.

METHODS

Medical records of patients with gallstone pancreatitis were reviewed retrospectively. Serial serum pancreatic enzymes and liver tests were recorded until the time of cholangiography. Laboratory trends were analyzed by comparing initial results obtained in the emergency department to subsequent results obtained 8-24 h, 24-48 h, and 48-72 h after presentation.

RESULTS

Of 154 patients with gallstone pancreatitis, 28 (18%) had persistent CBD stones at cholangiography. Complications and death were more frequent in patients with persistent CBD stones than in those without CBD stones (29% and 11% vs 12% and 1%, respectively; p < 0.05). Laboratory trends predicted both persistent CBD stones and complications of pancreatitis. When any laboratory value rose between admission and 24-48 h of hospitalization, persistent CBD stones were present in 31% of cases, versus 8% of those in whom all laboratory values remained constant or fell (p = 0.001). Likewise, complications occurred in 21% of those with any rising laboratory value, versus 8% of those in whom all values remained constant or fell (p < 0.05).

CONCLUSIONS

Patients with gallstone pancreatitis and rising serum chemistries had a 4-fold risk of persistent CBD stones and a nearly 3-fold risk of complications compared to patients in whom all chemistry values remained constant or fell. This simple prediction rule may identify patients with biliary pancreatitis who are most likely to benefit from early interventions to diagnose and remove persistent CBD stones.

Muromonab-CD3-induced neurotoxicity: report of two siblings, one of whom had subsequent cyclosporin-induced neurotoxicity

Muromonab-CD3 is widely used for immunosuppression in patients undergoing solid organ transplant. We report two siblings with oligomeganephronia and end-stage renal disease who developed encephalopathy and seizures from muromonab-CD3 following renal transplant. The first case is a 13-year-old girl who developed encephalopathy, seizure, and triparesis following renal transplant while muromonab-CD3 was used for immunosuppression. The second case was the 6-year-old sister of the first case, who also developed recurrent focal seizures while she was on muromonab-CD3 for renal transplant immunosuppression. In both cases, a sequential brain magnetic resonance image (MRI) showed progression of abnormalities from the cerebral cortex to the white matter. In the first case, the MRI normalized after muromonab-CD3 was discontinued. In the second case, the patient developed a leukoencephalopathy following cyclosporin administration. The pathophysiology of muromonab-CD3 encephalopathy is believed to be a disturbance to the blood-brain barrier mediated by cytokine release from lymphocyte stimulation by muromonab-CD3. Because the major histocompatibility complex genes are known to regulate cytokine responses, it is possible that the excessive production of cytokines that causes encephalopathy may occur in patients who share close major histocompatibility complex genes. Muromonab-CD3 in a patient whose sibling has developed cerebral complications from its use should be administered with caution. The second case suggests that muromonab-CD3 encephalopathy predisposes patients to develop cyclosporin neurotoxicity. Because the pathogenesis of muromonab-CD3 encephalopathy and cyclosporin-related cerebral complications are both potentially mediated through a disturbance of the blood-brain barrier, it is possible that one agent may predispose a patient to the complication of the other.

Internal levator advancement by Müller's muscle-conjunctival resection: technique and review

BACKGROUND

Müller's muscle-conjunctival resection surgery presumably works by advancing the levator aponeurosis of the upper eyelid. The amount of blepharoptosis and the lid's response to the instillation of phenylephrine hydrochloride onto the superior ocular fornix are used to determine the extent of surgery needed.

OBJECTIVES

To demonstrate the procedure developed and popularized by Allen M. Putterman, MD, performed by Michael Mercandetti, MD, MBA, and to describe the relationship between the amount of Müller's muscle-conjunctival resection performed and the amount of elevation achieved.

METHODS

Data were retrospectively analyzed based on surgical cases done over a 5-year period by one surgeon (A.M.P.).

RESULTS

A linear regression model was developed. From this regression a simple table correlating the amount of resection with the amount of elevation desired was derived.

CONCLUSION

The surgeon will need to modify the table based on his or her clinical experience and postoperative results.

Prevalence of dehiscences and fenestrations in modern American skulls

BACKGROUND

The purpose of this study was to examine the prevalence, distribution, and features of alveolar dehiscences and fenestrations in modern American skulls and correlate their presence with occlusal attrition, root prominence, and alveolar bone thickness.

METHODS

A representative sample of 146 dentate modern American skulls from a collection at the National Museum of Natural History were examined.

RESULTS

The skulls were from subjects ranging in age from 17 to 87 years old (mean 49.1 years). The mean number of teeth per skull was 22.7 and the mean number of either dehiscence or fenestration defects per skull was 3.0. Of the 3,315 individual teeth examined, 4.1% (135) had dehiscences and 9.0% (298) had fenestrations. A dehiscence was present in 40.4% of the skulls, and a fenestration was present in 61.6% of skulls. Mandibular canines were most often affected by dehiscences (12.9%), while maxillary first molars were most often affected by fenestrations (37.0%). Sixty-seven percent of dehiscences were found in the mandible, and 58% of fenestrations were found in the maxilla.

CONCLUSIONS

The presence of dehiscences and fenestrations were positively correlated with thin alveolar bone and negatively correlated with occlusal attrition. African-American males and Caucasian females were significantly more likely to have dehiscences, while African-American females were significantly more likely to have fenestrations.

Analysis of ordinal dental data: evaluation of conflicting recommendations

Although recommendations for the appropriate analysis of non-normal and ordinal-scaled data have appeared in the dental research literature for many years, there is no consensus. When one is conducting statistical tests for differences between groups, the central concern is whether it is safe to use parametric tests (e.g., analysis of variance), or if only non-parametric ranking tests should be considered. Relevant statistical and scientific issues associated with non-normality and measurement scale are reviewed, and three conclusions are reached regarding the analysis of dental data: (1) Parametric tests are sufficiently robust relative to typical violations of normality; (2) presumed statistical prohibitions against the application of parametric methods to ordinal data do not actually exist; and (3) 'ordinal' dental indices have sufficient quantitative meaning to be considered quasi-interval. For these reasons, parametric tests should not be avoided; they will be valid and usually more powerful and more easily applied to complex designs than non-parametric alternatives.

Measurement of proteases in human subgingival dental plaque by fluorescence polarization

Fluorescence polarization (FP) was examined as a rapid quantitative method to assay the proteases in subgingival plaque. Protease activity was measured by a decrease in FP at 0.5-min intervals over 5 min, using BODIPY-alpha-casein, a protein substrate. To quantitate activity, the least absolute deviation (LAD) slope for each assay was determined. Protease activity increased with the quantity of plaque (r=0.416, P<0.001). Of the 208 subgingival plaque samples, 87 contained detectable protease activity, with a mean of about 4 microg trypsin equivalents above a general background of 1 microg per site. The mean plaque protease activity of 89 paired samples from 15 individuals had decreased by 1.1 microg trypsin equivalents per site when measured at 8 months after tooth scaling and root planing (P<0.01). Most isolates of Porphyromonas gingivalis, Treponema denticola, Prevotella nigrescens, and Prevotella intermedia implicated in the pathogenesis of adult periodontitis exhibited high activity in the FP assay. The assay is rapid, quantitative and requires only one-tenth of the plaque sampled using a single pass with a Gracey curette at a single tooth site.

The tools of disability outcomes research functional status measures

OBJECTIVE

To review the major functional status measures currently used in rehabilitation research, including the domains and scope of functional status measures, as well as the psychometric properties of selected functional status measures and their use in adult rehabilitation populations.

DATA SOURCES

Measures of physical functioning widely used in rehabilitation research.

STUDY SELECTION

Major generic measures included the following activities of daily living and instrumental activities of daily living: the FIM instrument, the Katz Activities of Daily Living Scale, the Level of Rehabilitation Scale, the Barthel index, and the Patient Evaluation and Conference System. Measures were evaluated based on published evidence of validity, reliability, and sensitivity.

DATA EXTRACTION

Measures were chosen on the basis of the amount and quality of published research on the functional measures widely used in rehabilitation medicine. Independent research of computer databases and reviews of functional measures were conducted to determine suitability for inclusion. The quality and validity of the measures were assessed using standard psychometric guidelines.

DATA SYNTHESIS

Measures were evaluated based on published evidence of validity, reliability, sensitivity response and administrative burdens and instrument bias. Each criterion was graded on a 3-point scale reflecting the level of evidence.

CONCLUSION

Researchers in the field of disabilities research need to consider carefully study objectives when measuring physical functioning in people with disabilities.

Carboplatin is effective therapy for young children with progressive optic pathway tumors: a Pediatric Oncology Group phase II study

The Pediatric Oncology Group conducted a phase II study to evaluate the activity of carboplatin in children 5 years or younger with progressive optic pathway tumors (OPTs). Of the 51 patients accrued to this study, 1 was not eligible because the child was older than 6 years. Fifty patients were eligible and had either neuro-imaging or symptomatic evidence of progressive OPTs. Twenty-one of 50 had evidence of neurofibromatosis type I (NF-1). Therapy consisted of carboplatin 560 mg/m2 at 4-week intervals. Patients with stable disease or better after two courses were continued on therapy for 18 months or until progressive disease. Of the 50 eligible children, 39 had stable disease or better, and 34 completed the 18-month therapy. Our data are sufficient to conclude that the proportion of objective responses (complete, partial, or minor response or stable disease) exceeded 30% (P < 0.00001), and the approximate 95% confidence interval estimate of the objective response rate was 0.665 to 0.895. Twenty-one patients went off protocol because of progressive disease. Fifteen patients progressed during the 18-month therapy, and 6 patients progressed after completing therapy. Six children died with progressive disease. Major toxicities were neutropenia and thrombocytopenia, and 3 children experienced allergic reactions. Carboplatin is active and safe for the treatment of young children with progressive OPTs. The addition of other potentially active drugs may further increase the event-free survival for these children.

Early-onset Moyamoya syndrome in a patient with Down syndrome: case report and review of the literature

Moyamoya disease is a chronic occlusive cerebrovascular disorder. It can occur as a primary disease or as a syndrome associated with a variety of conditions. Usually it takes 1 to 2 years to develop a classic moyamoya pattern. We report a 20-month-old girl with Down syndrome and moyamoya syndrome who presented with seizure and hemiparesis. To our knowledge, this is the youngest case reported with moyamoya syndrome and Down syndrome. The prognosis and current treatment of moyamoya syndrome and its relation to Down syndrome are reviewed. There is some reason to speculate that the abnormalities associated with Down syndrome might create a vulnerability for the development of moyamoya syndrome.

Buccal alveolar exostoses: prevalence, characteristics, and evidence for buttressing bone formation

BACKGROUND

Buttressing bone formation has been described as the development of thickened or exostotic buccal alveolar bone in response to heavy occlusal forces. Little supporting evidence for this model has been found in previous literature, however, and there is little seen on the prevalence or characteristics of buccal alveolar exostoses.

METHODS

A sample of 416 selected teeth and investing bone in 52 modern skeletal specimens at the National Museum of Natural History were examined. Two measures of heavy occlusal function--periodontal ligament (PDL) width and occlusal attrition--were analyzed for their relationship to three parameters of buccal alveolar bone (exostoses, lipping, and overall thickness).

RESULTS

Buccal alveolar bone enlargements were found in 25% of all teeth examined: 18% were expressed as marginal bony lippings and 7% as buccal exostoses. Exostoses were mainly seen around maxillary molars and bicuspids, especially in males, while lippings were seen in molars, bicuspids, and mandibular incisors, with even gender distribution. When findings were controlled for arch and tooth type, no significant correlations were found between wider PDL spaces or occlusal attrition and exostotic, lipped, or thicker alveolar bone.

CONCLUSIONS

These results indicate a lack of anatomic evidence for the theory of buttressing bone formation and suggest that other factors may be of greater importance in the etiology of buccal bone enlargements. Incidentally, no correlation was found between widened PDL spaces or severe occlusal attrition and the presence of cervical loss of tooth structure, which casts doubt on the currently popular concept of abfraction.

Recovery of upper-extremity strength in complete and incomplete tetraplegia: a multicenter study

OBJECTIVE

To examine upper-extremity motor recovery of subjects with tetraplegia with both complete and incomplete injuries, to predict which patients and at what time they would recover a motor level.

DESIGN

Prospective, multicenter clinical study of upper-extremity motor recovery in subjects with acute traumatic spinal cord injury.

SETTING

Three regional spinal cord injury centers.

SUBJECTS

One hundred sixty-seven individuals with acute traumatic tetraplegia (144 males [86%], and 23 females [14%]) between the ages of 15 and 75 years (mean age, 35.5 yrs).

METHODS

Subjects were examined and classified using sequential manual muscle tests performed on admission, 72 hours, 1, 2, and 3 weeks, and 1, 2, 3, 6, 12, 18, and 24 months postinjury. C5 biceps, C6 extensor carpi radialis, C7 triceps, and C8 flexor digitorum profundus were evaluated using a 0-5 scale. Analyses of the right motor levels used a series of logistic regression models, and for multiple measurements on each subject, models were estimated using generalized estimating equations.

RESULTS

The analysis for recovery of the biceps for the C4 group showed 70% of complete compared with 90% of incomplete injuries recovered (p < .001); of the extensor carpi radialis in the C5 group, 75% complete and 90% incomplete recovered (p < .002); and of the triceps in the C6 group, 85% of complete and 90% of incomplete injuries recovered (p < .16).

CONCLUSION

Predicting future potential for upper-extremity motor recovery and for independence in self-care in groups of patients at a specific motor level is possible within the first week of injury.

Stress fractures of the pelvis in female navy recruits: an analysis of possible mechanisms of injury

The purpose of our study was to investigate possible risk factors and mechanisms for the development of pelvic stress fractures in female Navy recruits. We used a case-control retrospective study of female Navy recruits undergoing basic military training. We compared anthropometric and activity data between recruits with pelvic stress fractures (N = 25) and female recruits who completed training without injury (N = 61). Recruits developing pelvic stress fractures were significantly (p < 0.05) shorter and lighter and were more frequently Asian or Hispanic than recruits without stress fractures. In addition, recruits with pelvic stress fractures reported marching in the back of their training division, were road guards, and felt that their stride was too long during training activities more often than recruits without injury. Self-reported fitness, activities before recruit training, or a history of amenorrhea was not found to be associated with the development of a pelvic stress fracture in our population.

Characteristics of the Functional Independence Measure in traumatic spinal cord injury

OBJECTIVES

The characteristics of the Functional Independence Measure (FIM) were examined for spinal cord injury (SCI) in regard to norms over time by level and completeness of injury, differential benefit of motor and cognition subscales, and "ceiling effect" after rehabilitation discharge.

DESIGN

Descriptive study of raw FIM data collected prospectively at admission and discharge from acute inpatient rehabilitation, and at 1, 2, and 5 years after injury.

SETTING

National Database of the 18 Spinal Cord Injury Model Systems.

SUBJECTS

Persons with SCI, age 16 and over, with functionally complete injuries at inpatient rehabilitation admission (ASIA grades A, B, or C), admitted to Model System an average of 8 days after injury (standard deviation = 13, median = 1 day). Maximum sample sizes for which data were available were: at rehabilitation admission, 3,971 cases; at discharge, 4,033; at year 1 postinjury, 903; 2 years, 712; and 5 years, 570.

OUTCOME MEASURES

The FIM motor and cognition subscales.

RESULTS

There is a substantial ceiling effect of the FIM cognition items even by inpatient rehabilitation discharge, ie, 80% to 90% of the cases average 6 to 7 (independent or modified independence) across the 5 FIM cognition items. At 1 year 89% to 97% of cases were rated independent. FIM motor items were consistent with level of injury and neurologic status. Motor items (excluding locomotion items) were highly intercorrelated (correlations range from .58 to .92 for self care, sphincter control, and mobility items). Trends over years 1, 2, and 5 were stable for both motor and cognition subscales. FIM motor gains were greatest between admission and discharge and gains continued through 1 year after injury, but at a much-decreased rate.

CONCLUSIONS

The cognition items are not informative for detecting changes over time in SCI; at best, these items could serve as a crude cognition screening assessment. Motor items, in contrast, appear to reflect well the functional status of individuals. High correlations among several of the motor items suggest item redundancy. FIM motor scores illustrated the improvements in neurologic and ASIA scores in appropriate cases. Individuals with ASIA impairment grades of B or C at admission make the most gains in FIM motor scores.

Cyclophosphamide for the treatment of progressive low-grade astrocytoma: a Pediatric Oncology Group phase II Study

PURPOSE

Results of a phase II trial of cyclophosphamide (CPM) for children with progressive low-grade astrocytoma are reported.

PATIENTS AND METHODS

Fifteen patients with a median age of 39 months (range, 2 to 71) were included in this study. The tumors of 11 children were located in the optic pathway, hypothalamus, or thalamus. Four courses of intravenous CPM 1.2 g/m2 were administered every 3 weeks during the upfront window portion of this protocol. Subsequently, chemotherapy was to continue with CPM, vincristine, and carboplatin for 2 years.

RESULTS

By study design, the first 14 patients were centrally reviewed after completion of the initial 4 CPM courses. Toxicity was primarily hematologic. One patients had a complete response, 8 had stable disease, and 5 had progressive disease (PD). The excessive number of children with PD prompted study closure.

CONCLUSION

CPM as used in this protocol showed insufficient activity against astrocytoma to justify further patient accrual.

There is no role for hyperfractionated radiotherapy in the management of children with newly diagnosed diffuse intrinsic brainstem tumors: results of a Pediatric Oncology Group phase III trial comparing conventional vs. hyperfractionated radiotherapy

PURPOSE

In June 1992, POG began accrual to a phase III study, POG-9239, designed to compare the time to disease progression, overall survival, and toxicities observed in children with newly diagnosed brainstem tumor treated with 100 mg/m2 of infusional cisplatin and randomized to either conventional vs. hyperfractionated radiotherapy.

METHODS AND MATERIALS

Patients eligible for study were those between 3 and 21 years of age with previously untreated tumors arising in the pons. Histologic confirmation of diagnosis was not mandatory, provided that the clinical and MRI scan findings were typical for a diffusely infiltrating pontine lesion. Treatment consisted of a six-week course of local field radiotherapy with either once a day treatment of 180 cGy per fraction to a total dose of 5400 cGy (arm 1) or a twice a day regimen of 117 cGy per fraction to a total dose of 7020 cGy (the second of the three hyperfractionated dose escalation levels of POG-8495) (arm 2). Because of previously reported poor results with conventional radiotherapy alone, cisplatin was included as a potential radiosensitizer in an attempt to improve progression-free and ultimate survival rates. Based on results of the phase I cisplatin dose escalation trial, POG-9139, 100 mg/m2 was chosen for this trial and was delivered by continuous infusion over a 120-hour period, beginning on the first day of radiotherapy and repeated during weeks 3 and 5. One hundred thirty eligible patients were treated on protocol, 66 on arm 1 and 64 on arm 2.

RESULTS

The results we report are from time of diagnosis through October 1997. For patients treated on arm 1, the median time to disease progression (defined as time to off study) was 6 months (range 2-15 months) and the median time to death 8.5 months (range 3-24 months); survival at 1 year was 30.9% and at 2 years, 7.1%. For patients treated on arm 2, the corresponding values were 5 months (range 1-12 months) and 8 months (range 1-23 months), with 1- and 2-year survival rates at 27.0% and 6.7%, respectively. Evaluation of response by MRI at 4 or 8 wks post treatment was available in 108 patients and revealed a complete response in 1 patient of each Rx arm, a partial response (> 50% decrease in size) in 18 patients of arm 1 and 15 patients of arm 2, minimal to no response (stable) in 25 patients of arm 1 and 23 patients of arm 2, and progressive disease in 13 patients of arm 1 and 12 patients of arm 2. The pattern of failure was local in all patients. Morbidity of treatment was similar in both Rx arms, with no significant toxicity (including hearing loss) reported. Autopsy was performed in 6 patients, and confirmed the presence of extensive residual tumor in these cases.

CONCLUSION

The major conclusion from this trial is that the hyperfractionated method of Rx 2 did not improve event-free survival (p = 0.96) nor did it improve survival (p = 0.65) over that of the conventional fractionation regimen of Rx 1, and that both treatments are associated with a poor disease-free and survival outcome.

Palatal tubercles, palatal tori, and mandibular tori: prevalence and anatomical features in a U.S. population

The prevalence and features of 3 types of exostoses commonly encountered during periodontal surgery were studied in a sample of 328 modern American skulls drawn from the collection at the American Museum of Natural History. Measurements were made of the height, width, and breadth of exostoses. The relationship to teeth or other skeletal structures was also recorded. Palatal tubercles were observed in 56% of all skulls (69% of all dentate skulls), with higher prevalences among males and African-Americans. Palatal tubercles were commonly associated with second and third molars, and were usually directly lateral to and a mean of 11.4 mm from the greater palatine foramen. Mandibular tori were observed in 27% of all skulls (42% of dentate skulls), with higher prevalences seen among African-Americans and males. The importance of these findings relates to the frequent need for exostosis removal to permit proper flap adaptation, especially in the posterior maxilla, and to the potential use of the mandibular and palatal tori as sources of autogenous cortical bone.

Development of new photopolymerizable dental sealants

This paper describes the results obtained in the optimization of the composition of dental sealants in relation to the nature and proportions of monomer mixtures and photoinitiating system employed. The quantification and variation of certain parameters which determine the quality of a dental sealant (such as viscosity and penetrating power, residual double bonds, solubility and absorption, volume shrinkage and certain specific mechanical properties) have resulted in the development of new formulations. The composition which has achieved the best results of all the above properties was that corresponding to the monomer mixture bis-GMA/tri(ethylene glycol) dimethacrylate (TEGDMA) 40/60 wt%, and the photoinitiating system camphorquinone (CQ) with co-initiators N,N,3,5-tetramethyaniline (TMA) or N,N-dimethyl-p-toluidine (DMPT) in the ratio 1:1. The final properties and characteristics of the obtained formulations are superior to those of commercial dental sealants currently in use.

Second malignancies in young children with primary brain tumors following treatment with prolonged postoperative chemotherapy and delayed irradiation: a Pediatric Oncology Group study

Between 1986 and 1990, the Pediatric Oncology Group conducted a study in which 198 children younger than 3 years of age with malignant brain tumors were treated with prolonged postoperative chemotherapy in an effort to delay irradiation and reduce long-term neurotoxicity. Children younger than 2 years of age received 24 months of chemotherapy followed by irradiation, and those between 2 and 3 years of age received 12 months of chemotherapy plus irradiation. Chemotherapy was given in 28-day cycles (AAB, AAB), with cycle A = vincristine (0.065 mg/kg) intravenously on days 1 and 8 and cyclophosphamide (65 mg/kg) intravenously on day 1, and cycle B = cisplatinum (4 mg/kg) intravenously on day 1 and etoposide (6.5 mg/kg) intravenously on days 3 and 4. Five of the 198 children developed second malignancies, with a cumulative risk at 8 years of 11.3% (95% confidence interval [CI], 0-39%). Four of the five second malignancies occurred in children younger than 2 years of age at diagnosis, with a cumulative risk at 8 years of 18.9% (CI, 0-70%). Initial diagnoses were choroid plexus carcinoma (2 children), ependymoma (1 child), desmoplastic infantile ganglioglioma (2 children), and medulloblastoma (1 child). Duration from diagnosis of initial tumor to second malignancy was 33, 35, 57, 66, and 92 months. Three children younger than 2 years of age developed lymphoproliferative disease, that is, myelodysplastic syndrome (2 children), both with monosomy 7 deletions, and acute myelogenous leukemia (1 child), after 24 to 26 cycles of chemotherapy, including 8 cycles of etoposide. Two of 3 received craniospinal irradiation (2,560/3,840 cGy) and (3,520/5,320 cGy). Time to second malignancy was 7 years 8 months, 4 years 9 months, and 2 years 9 months. Two children developed solid tumors, at 5 years 6 months and 2 years 11 months, respectively, after initiation of treatment. A sarcoma developed after 26 cycles of chemotherapy and no irradiation, and a meningioma developed after 12 cycles of chemotherapy and local craniospinal irradiation. Potential causative factors for this high rate of secondary malignancies include prolonged use of alkylating agents and etoposide with or without irradiation.

Human SLUG gene organization, expression, and chromosome map location on 8q

SLUG is a member of the snail family of zinc finger proteins. It is involved in epithelial to mesenchyme cell transition during neurulation and plays a role in limb bud development. We have isolated and described the human SLUG gene by sequencing a region spanning 4034 bp. The human SLUG gene contains three exons. The SLUG transcript is 2.2 kb and is found in placenta and adult heart, pancreas, liver, kidney, and skeletal muscle, and it codes for a protein of 268 amino acids and 29.989 kDa. This protein contains five zinc finger regions. The human SLUG protein is 95, 93, and 88% homologous to mouse, chicken, and Xenopus slug, respectively, but shows only 47% homology to mouse Snail. The zinc finger region is 100% identical between human and mouse Slug. Slug maps to the long arm of chromosome 8, closely linked to D8S2090 between D8S519 and D8S1098.

A test of the 1992 International Standards for Neurological and Functional Classification of Spinal Cord Injury

This study was designed to test the 1992 International Standards for Neurological and Functional Classification of Spinal Cord Injury. One hundred and six professionals in the field of spinal cord injury attending an instructional course at the 1994 ASIA Meeting participated in the test. Participants completed a pretest and posttest in which they classified two patients who had a spinal cord injury (one with complete tetraplegia and one with incomplete paraplegia) by sensory and motor levels, zone of partial preservation (ZPP), ASIA Impairment Scale and completeness of injury. Between tests, three members of the ASIA Standards Executive Committee gave presentations on the neurological assessment, scoring, scaling and classification of spinal cord injury and a video of the actual examinations of the two cases was viewed. Percent 'correct' (as defined by the ASIA Standards Committee) was calculated for sensory and motor levels, ZPP, ASIA Impairment and completeness. Overall, the analyses showed that participants had very little difficulty in correctly classifying the patient with complete tetraplegia. Pretests scores ranged from 72% (left motor level) to 96% (complete injury), posttest scores from 73% (left motor level) to 100% correct (complete injury). For the patient with incomplete paraplegia (Case 2), scores were considerably lower. Pretest scores ranged from 16% (right motor level) to 95% correct (incomplete injury); posttest scores from 21% (right motor level) to 97% correct (incomplete injury). The results showed that further revisions of the 1992 Standards and more training is needed to ensure accurate classification of spinal cord injury.

A quantile plot for simultaneous representation of clinical and statistical attributes of probing change: application to early identification of the downhill patient

When multiple periodontal sites are observed in patients over time there is an intention to identify those sites where there is important change, typically loss of attachment or increase in probing depth. A change may be declared if it: (a) exceeds a threshold level, and/or (b) is determined to be statistically significant (e.g. regression slope different from zero), perhaps after (c) that significance level has been corrected for multiple testing. These criteria are not often considered when clinical or research decisions are made and there is no universal protocol for their evaluation. A quantile (uniform probability) plot, modified to incorporate additional information, is proposed as a graphical method for the display of changes at multiple sites within a mouth. This plot identifies, for each site, clinical changes beyond a threshold, site-wise statistical significance and statistical significance adjusted for multiple testing. These alternative criteria for attachment change are, thereby, made explicit, providing a detailed evaluative context. In addition, this methodology permits incorporation of an estimation procedure for the number of sites for which the null hypothesis of no change is false. This statistic can provide evidence of progressive disease even when no site has significant clinical or statistical change and even if the average change is zero. Use of the quantile plot was elucidated by application to simulated data, and to a clinical dataset using a BASIC program to automate the computational process. In the clinical example presented, the approach appeared more effective in detecting periodontal change than traditional clinical and statistical criteria. Pending technical refinement, this graphical approach may represent a new tool for the early identification of the downhill patient.

Quantitative contribution of NHE2 and NHE3 to rabbit ileal brush-border Na+/H+ exchange

Intestinal neutral NaCl absorption, which is made up of brush-border (BB) Na+/H+ exchange linked to BB Cl-/HCO3- exchange, is up- and downregulated as part of digestion and diarrheal diseases. Glucocorticoids stimulate ileal NaCl absorption and BB Na+/H+ exchange. Intestinal BB contains two Na+/H+ exchanger isoforms, NHE2 and NHE3, but their relative roles in rabbit ileal BB Na+/H+ exchange has not been determined. A technique to separate the contribution of NHE2 and NHE3 to ileal BB Na+/H+ exchange activity was standardized by using an amiloride-related compound, HOE-694. Under basal conditions, both NHE2 and NHE3 contribute approximately 50% to ileal Na+/H+ exchange. Glucocorticoids (methylprednisolone) increase BB Na+/H+ exchange (2.5 times) but increase only ileal NHE3 activity (4.1 times), without an effect on NHE2 activity. Thus ileal BB Na+/H+ exchange in animals treated with glucocorticoids is 69% via NHE3. A quantitative Western analysis for NHE3 was developed, using as an internal standard a fusion protein of the COOH-terminal 85 amino acids of NHE3 and maltose binding protein. Glucocorticoid treatment increased the amount of BB NHE3. The quantitative Western analysis showed that NHE3 makes up 0.018% of ileal BB protein in control rabbits and 0.042% (2.3 times as much) in methylprednisolone-treated rabbits. Methylprednisolone treatment did not alter the amount of ileal BB NHE2 protein. NHE3 turnover number was estimated to be 458 cycles/s under basal conditions and 708 cycles/s in glucocorticoid-treated ileum. Thus methylprednisolone stimulates ileal BB Na+/H+ exchange activity only by an effect on NHE3 and not on NHE2; it does so primarily by increasing the amount of BB NHE3, although it also increases the NHE3 turnover number.

Prognostic factors in infants and very young children with intracranial ependymomas

The Pediatric Oncology Group (1986-1990) conducted a study in which 48 children <3 years of age with intracranial ependymomas were treated with prolonged postoperative chemotherapy (CT) and delayed RT. Thirty-one children, 0-23 months of age at diagnosis (Gp A) received 2 years of CT followed by RT; while 17 children, 24-36 months of age at diagnosis (Gp B) received CT for 1 year followed by radiation. One-year survivals were 87% (Gp A) and 94% (Gp B) and 2-year survivals were 67% (Gp A) and 82% (Gp B). In subsequent years a significant divergence in survivals according to age has been noted (p = 0.04). Five-year survivals were 25.7% (Gp A) vs. 63.3% (Gp B). The curves began to diverge 1 year following diagnosis. Other than age, the only significant prognostic factor was degree of surgical resection: 5-year survivals were 66% (total resection) vs. 25% (subtotal resection). Neither the presence of metastases, degree of anaplasia nor the degree of surgical resection varied significantly according to age at diagnosis. The most likely reason for the difference in survivals between the two age groups relates to the timing of radiation following CT, i.e., 1-year delay in children 24-36 months of age compared to a 2-year delay in children 0-23 months of age. An alternative but less likely hypothesis is that ependymomas in the younger children have a more aggressive biology. In contrast, survivals in the 24- to 36-month group are much better than previous reports in the literature suggesting that prolonged postoperative CT may allow both a delay in CRT as well as provide improved survivals. Based on these results, future treatment trials should emphasize maximal surgical resection and a delay in radiation of no more than 1 year.

A prospective study of sealant application in navy recruits

A 3-year prospective study was designed to evaluate sealants in preventing the formation and progression of caries in a young adult military population. United States Navy dentists performed dental examinations on recruits being in-processed at the Naval Training Center, San Diego, California. Contralateral molar pairs (same arch) without caries or restorations were selected. Occlusal decalcification and lesions limited to enamel were also eligible, but teeth with proximal decalcification were disqualified. The sample consisted of 860 molar pairs in 529 Navy recruits, each contributing one or two pairs. Required annual dental examinations provided follow-up data, with results being recorded on postcards that were mailed back to the investigator. Yearly response rates were as follows: 1 year, 62.2% (483 molar pairs); 2 year, 47.8% (378 molar pairs); and 3 year, 41.4% (317 molar pairs). The response rate for pairs having at least one observation during the 3-year follow-up was 72.6% (563 molar pairs), with a caries conversion rate of 1.2% (7 teeth) on sealed teeth and 5.3% (32 teeth) on control teeth, yielding 35 discordant molar pairs on 33 recruits (30 on control teeth and 5 on sealed teeth) (p < 0.0001). These results confirm the efficacy of sealants in significantly reducing the rate caries in a young adult military population.

Pneumomediastinum during relapse of ulcerative colitis

Pneumomediastinum can be caused by gas dissecting along fascial tissue planes into the mediastinum from remote locations, including the retroperitoneum. One potential source of retroperitoneal gas is the colon. We present the third reported case of pneumomediastinum (plus pneumothorax and subcutaneous emphysema) without free intraperitoneal gas developing during an attack of ulcerative colitis. Because there was no colonic perforation noted at colectomy, the extracolonic gas was presumed to originate from a microscopic or partial thickness perforation of the colon. GI perforation must be considered not only in patients who have free intraperitoneal gas but also in those who present with symptoms, signs, or studies consistent with retroperitoneal gas, such as subcutaneous emphysema, pneumomediastinum, or pneumothorax.

The role of the Internet in medical decision making

The Internet has dramatically changed the means by which information is obtained. Accurate, up-to-date information is vital to maintain the quality of healthcare, especially as US healthcare delivery changes to a primary care-based system. The availability of this new and potentially vast source of information also affects strategies for medical decision making. In this article, use of online information in our medical center is discussed, together with the impact of a locally-developed decision support system. This system first contained components for differential diagnosis as well as computer-assisted instruction. Initially, online searching was limited to Medline literature searches. This component has now been expanded to include important new tools for accessing medical information on the Internet.

Use of shoulder flexors to achieve isometric elbow extension in C6 tetraplegic patients during weight shift

The anterior deltoid muscle has been found to be active during elbow extension in normal volunteers and in C6 tetraplegic patients lacking a functional triceps. Using surface electromyography (EMG) on normal volunteers and on patients with spinal cord injury (SCI) at the C6 motor level, we evaluated whether the anterior deltoid and biceps brachii muscles are active during closed chain elbow extension in a simulated weight shift position. Thirteen normal volunteers performed isometric contractions at 5 submaximal levels of force ranging from 4-25 kg. Six SCI patients performed isometric contractions at force levels of 20%, 40%, 60%, 80% and 100% maximum voluntary contraction (MVC). Surface EMG over the right biceps, triceps, and anterior deltoid muscles was recorded for each participant and the root mean square (rms) electromyographic activity level for each muscle was determined at each level of force. Statistical analyses using repeated ANOVA with Tukey HSD post-hoc tests were performed for each level of force. The results indicated increasing rms activity of the triceps and anterior deltoid muscles with increasing force in normal volunteers to a significant degree (P < 0.05). SCI patients showed significant increasing activity of the anterior deltoid with increasing force, but showed minimal triceps rms activity. In both groups, the biceps showed minimal rms activity. SCI patients exhibited significantly greater rms activity of the anterior deltoid at low force compared with normal volunteers. The results suggest that the anterior deltoid aids in isometric elbow extension during a simulated weight shift maneuver.