Perception of dysphonic voice quality by naive listeners

For clinical assessment as well as student training, there is a need for information pertaining to the perceptual dimensions of dysphonic voice. To this end, 24 naive listeners judged the similarity of 10 female and 10 male vowel samples, selected from within a narrow range of fundamental frequencies. Most of the perceptual variance for both sets of voices was associated with "degree of abnormality" as reflected by perceptual ratings as well as combined acoustic measures, based upon filtered and unfiltered signals. A second perceptual dimension for female voices was associated with high frequency noise as reflected by two acoustic measures: breathiness index (BRI) and a high-frequency power ratio. A second perceptual dimension for male voices was associated with a breathy-overtight continuum as reflected by period deviation (PDdev) and perceptual ratings of breathiness. Results are discussed in terms of perceptual training and the clinical assessment of pathological voices.

Association between method of delivery and maternal rehospitalization

CONTEXT

Despite nearly 4 million deliveries in the United States each year, minimal information exists on unintended health consequences following childbirth, particularly in relation to delivery method.

OBJECTIVE

To assess the risk for maternal rehospitalization associated with cesarean or assisted vaginal delivery compared with spontaneous vaginal delivery.

DESIGN

Retrospective cohort study of data from the Washington State Birth Events Record Database for 1987 through November 1, 1996.

SETTING AND PARTICIPANTS

All primiparous women without selected chronic medical conditions who delivered live singleton infants in nonfederal short-stay hospitals in Washington State (N =256,795).

MAIN OUTCOME MEASURES

Relative risks (RRs) of rehospitalization within 60 days of cesarean or assisted vaginal vs spontaneous vaginal deliveries.

RESULTS

A total of 3149 women (1.2%) were rehospitalized within 60 days of delivery. In logistic regression analyses adjusting for maternal age, rehospitalization was found to be more likely among women with cesarean delivery (RR, 1.8; 95% confidence interval [CI], 1.6-1.9) or assisted vaginal delivery (RR, 1.3; 95% CI, 1.2-1.4) than among women with spontaneous vaginal delivery. Cesarean delivery was associated with significantly increased risks of rehospitalization for uterine infection, obstetrical surgical wound complications, and cardiopulmonary and thromboembolic conditions. Among women with assisted vaginal delivery, significant increased risks were seen for rehospitalization with postpartum hemorrhage, obstetrical surgical wound complications, and pelvic injury.

CONCLUSIONS

Women with cesarean and assisted vaginal deliveries were at increased risk for rehospitalization, particularly with infectious morbidities. Effective strategies for preventing and controlling peripartum infection should be an obstetrical priority.

Fabrication of a trileaflet heart valve scaffold from a polyhydroxyalkanoate biopolyester for use in tissue engineering

Previously, we reported the implantation of a single tissue engineered leaflet in the posterior position of the pulmonary valve in a lamb model. The major problems with this leaflet replacement were the scaffold's inherent stiffness, thickness, and nonpliability. We have now created a scaffold for a trileaflet heart valve using a thermoplastic polyester. In this experiment, we show the suitability of this material in the production of a biodegradable, biocompatible scaffold for tissue engineered heart valves. A heart valve scaffold was constructed from a thermoplastic elastomer. The elastomer belongs to a class of biodegradable, biocompatible polyesters known as polyhydroxyalkanoates (PHAs) and is produced by fermentation (Metabolix Inc., Cambridge, MA). It was modified by a salt leaching technique to create a porous, three-dimensional structure, suitable for tissue engineering. The trileaflet heart valve scaffold consisted of a cylindrical stent (1 mm X 15 mm X 20 mm I.D.) containing three valve leaflets. The leaflets were formed from a single piece of PHA (0.3 mm thick), and were attached to the outside of the stent by thermal processing techniques, which required no suturing. After fabrication, the heart valve construct was allowed to crystallize (4 degrees C for 24 h), and salt particles were leached into doubly distilled water over a period of 5 days to yield pore sizes ranging from 80 to 200 microns. Ten heart valve scaffolds were fabricated and seeded with vascular cells from an ovine carotid artery. After 4 days of incubation, the constructs were examined by scanning electron microscopy. The heart valve scaffold was tested in a pulsatile flow bioreactor and it was noted that the leaflets opened and closed. Cells attached to the polymer and formed a confluent layer after incubation. One advantage of this material is the ability to mold a complete trileaflet heart valve scaffold without the need for suturing leaflets to the conduit. Second advantage is the use of only one polymer material (PHA) as opposed to hybridized polymer scaffolds. Furthermore, the mechanical properties of PHA, such as elasticity and mechanical strength, exceed those of the previously utilized material. This experiment shows that PHAs can be used to fabricate a three-dimensional, biodegradable heart valve scaffold.

Tissue-engineered valved conduits in the pulmonary circulation

OBJECTIVE

Bioprosthetic and mechanical valves and valved conduits are unable to grow, repair, or remodel. In an attempt to overcome these shortcomings, we have evaluated the feasibility of creating 3-leaflet, valved, pulmonary conduits from autologous ovine vascular cells and biodegradable polymers with tissue-engineering techniques.

METHODS

Endothelial cells and vascular medial cells were harvested from ovine carotid arteries. Composite scaffolds of polyglycolic acid and polyhydroxyoctanoates were formed into a conduit, and 3 leaflets (polyhydroxyoctanoates) were sewn into the conduit. These constructs were seeded with autologous medial cells on 4 consecutive days and coated once with autologous endothelial cells. Thirty-one days (+/-3 days) after cell harvesting, 8 seeded and 1 unseeded control constructs were implanted to replace the pulmonary valve and main pulmonary artery on cardiopulmonary bypass. No postoperative anticoagulation was given. Valve function was assessed by means of echocardiography. The constructs were explanted after 1, 2, 4, 6, 8, 12, 16, and 24 weeks and evaluated macroscopically, histologically, and biochemically.

RESULTS

Postoperative echocardiography of the seeded constructs demonstrated no thrombus formation with mild, nonprogressive, valvular regurgitation up to 24 weeks after implantation. Histologic examination showed organized and viable tissue without thrombus. Biochemical assays revealed increasing cellular and extracellular matrix contents. The unseeded construct developed thrombus formation on all 3 leaflets after 4 weeks.

CONCLUSION

This experimental study showed that valved conduits constructed from autologous cells and biodegradable matrix can function in the pulmonary circulation. The progressive cellular and extracellular matrix formation indicates that the remodeling of the tissue-engineered structure continues for at least 6 months.

Evaluation of biodegradable, three-dimensional matrices for tissue engineering of heart valves

A crucial factor in tissue engineering of heart valves is the type of scaffold material. In the following study, we tested three different biodegradable scaffold materials, polyglycolic acid (PGA), polyhydroxyalkanoate (PHA), and poly-4-hydroxybutyrate (P4HB), as scaffolds for tissue engineering of heart valves. We modified PHA and P4HB by a salt leaching technique to create a porous matrix. We constructed trileaflet heart valve scaffolds from each polymer and tested them in a pulsatile flow bioreactor. In addition, we evaluated the cell attachment to our polymers by creating four tubes of each material (length equals 4 cm; inner diameter, 0.5 cm), seeding each sample with 8,000,000 ovine vascular cells, and incubating the cell-polymer construct for 8 days (37 degrees C and 5% CO2). The seeded vascular constructs were exposed to continuous flow for 1 hour. Analysis of samples included DNA assay before and after flow exposure, 4-hydroxyproline assay, and environmental scanning electron microscopy (ESEM). We fabricated trileaflet heart valve scaffolds from porous PHA and porous P4HB, which opened and closed synchronously in a pulsatile bioreactor. It was not possible to create a functional trileaflet heart valve scaffold from PGA. After seeding and incubating the PGA-, PHA-, and P4HB-tubes, there were significantly (p < 0.001) more cells on PGA compared with PHA and P4HB. There were no significant differences among the materials after flow exposure, but there was a significantly higher collagen content (p < 0.017) on the PGA samples compared with P4HB and PHA. Cell attachment and collagen content was significantly higher on PGA samples compared with PHA and P4HB. However, PHA and P4HB also demonstrate a considerable amount of cell attachment and collagen development and share the major advantage that both materials are thermoplastic, making it possible to mold them into the shape of a functional scaffold for tissue engineering of heart valves.

Fractionated stereotactic radiosurgery and preservation of hearing in patients with vestibular schwannoma: a preliminary report

OBJECTIVE

Microsurgery and stereotactic radiosurgery (SRS) for vestibular schwannomas are associated with a relatively high incidence of sensorineural hearing loss. A prospective trial of fractionated SRS was undertaken in an attempt to preserve hearing and minimize incidental cranial nerve injury.

METHODS

Thirty-three patients with vestibular schwannomas were treated with 2100 cGy in three fractions during a 24-hour period using conventional frame-based linear accelerator radiosurgery. The median tumor diameter was 20 mm (range, 7-42 mm). Baseline and follow-up evaluations included audiometry and contrast-enhanced magnetic resonance imaging. End points were tumor progression, preservation of serviceable hearing, and treatment-related complications.

RESULTS

Thirty-one patients (32 tumors) were assessable for tumor progression and treatment-related complications and 21 patients for preservation of serviceable hearing, with a median follow-up interval of 2 years (range, 0.5-4.0 yr). Tumor regression or stabilization was documented in 30 patients (97%) and tumor progression in 1 (3%). The patient with tumor progression remains asymptomatic and has not required surgical intervention. Five patients (16%) developed trigeminal nerve injury at a median of 6 months (range, 4-12 mo) after SRS; two of these patients had preexisting trigeminal neuropathy. One patient (3%) developed facial nerve injury (House-Brackmann Class 3) 7 months after SRS. Preservation of useful hearing (Gardner-Robertson Class 1-2) was 77% at 2 years. All patients with pretreatment Gardner-Robertson Class 1 to 2 hearing maintained serviceable (Class 1-3) hearing as of their last follow-up examination.

CONCLUSION

Three-fraction SRS with a conventional stereotactic frame is feasible and well tolerated in the treatment of acoustic neuroma. This study demonstrates a high rate of hearing preservation and few treatment-related complications among a relatively high-risk patient cohort (tumors >15 mm or neurofibromatosis Type 2). Longer follow-up will be required to assess the durability of tumor control.

The expression of proinflammatory cytokine mRNA in the sciatic-tibial nerve of ischemia-reperfusion injury

We evaluated the proinflammatory cytokines, TNF-alpha and IL-1beta, mRNA expression in the rat sciatic and tibial nerves following ischemia-reperfusion (IR) injury, using competitive RT-PCR, to explore the role of cytokines in IR injury. The expressions of both TNF-alpha and IL-1beta mRNA were related to severity of ischemia and occurred with reperfusion rather than ischemia alone. TNF-alpha gene expression peaked at 24 h of reperfusion, while that of IL-1beta peaked at 12 h. These data support the notion that the proinflammatory cytokines TNF-alpha and IL-1beta are involved in the inflammatory response of IR injury to the peripheral nervous system and may be involved in the pathophysiology of ischemic fiber degeneration.

Short musculoskeletal function assessment questionnaire: validity, reliability, and responsiveness

BACKGROUND

A short questionnaire on functional status was designed for use in community-based outcome studies and in the management of individual patients who have musculoskeletal disease. As most musculoskeletal care is delivered in community practices, short, validated instruments are necessary to perform clinical studies on the effectiveness of treatment in this setting.

METHODS

A forty-six-item questionnaire was created as an extension of the work to develop the longer, 101-item Musculoskeletal Function Assessment (MFA) questionnaire. The Short Musculoskeletal Function Assessment (SMFA) questionnaire consists of the dysfunction index, which has thirty-four items for the assessment of patient function, and the bother index, which has twelve items for the assessment of how much patients are bothered by functional problems. The SMFA questionnaire was evaluated for reliability, validity, and responsiveness in a population of 420 patients who had a musculoskeletal disease or injury.

RESULTS

The SMFA questionnaire demonstrated excellent internal consistency and stability, with most values greater than 0.90. Content validity for the dysfunction and bother indexes was supported with very little skew (less than 1.00), few ceiling effects (less than 5 percent), and no floor effects. Convergent validity was supported with significant correlations between the SMFA dysfunction and bother indexes and the physicians' ratings of patient function (for example, activities of daily living, recreational and leisure activities, and emotional function [rho > or = 0.40]) and standard clinical measures (for example, grip strength and walking speed [r > or = 0.401). Convergent and discriminant construct validity of the SMFA indexes were demonstrated (p < 0.01) in comparisons with clinical, demographic, Short Form-36 (SF-36), and life-change data. The responsiveness of the SMFA questionnaire to change over time was demonstrated with standardized response means ranging from moderate (0.76) to large (-1.14) for patients who had changes in health status.

CONCLUSIONS

The SMFA questionnaire may be used for clinical assessments of the impact of treatment in groups of patients who have musculoskeletal disease or injury. It also may be used in clinical settings to provide reliable and valid assessments of the health status of an individual patient.

Evaluation of Maize Streak Virus Pathogenicity in Differentially Resistant Zea mays Genotypes

ABSTRACT We devised a rapid technique for the objective and precise assessment of both the pathogenicity of maize streak virus (MSV) isolates and the MSV resistance of maize genotypes. The technique involves the use of agroinoculation to infect maize seedlings and the objective symptom evaluation by quantification of infection rates, stunting, and chlorotic leaf areas. In assessing the MSV resistance of 19 maize genotypes, we describe how the use of differentially virulent virus isolates enables the analysis of MSV resistance phenotypes, ranging from extremely susceptible to completely immune. We further demonstrate how quantification of chlorotic leaf areas by image analysis permits differentiation between degrees of MSV resistance that are indistinguishable from one another using currently employed symptom assessment approaches. Using chlorotic area measurements, we quantify the virulence of a diverse group of 10 MSV isolates and, through agroinoculation of differentially susceptible maize genotypes, we demonstrate the use of our technique in evaluating the pathogenicity of these isolates.

Solid state NMR studies of hydrogen bonding in a citrate synthase inhibitor complex

The ionization state and hydrogen bonding environment of the transition state analogue (TSA) inhibitor, carboxymethyldethia coenzyme A (CMX), bound to citrate synthase have been investigated using solid state NMR. This enzyme-inhibitor complex has been studied in connection with the postulated contribution of short hydrogen bonds to binding energies and enzyme catalysis: the X-ray crystal structure of this complex revealed an unusually short hydrogen bond between the carboxylate group of the inhibitor and an aspartic acid side chain [Usher et al. (1994) Biochemistry 33, 7753-7759]. To further investigate the nature of this short hydrogen bond, low spinning speed 13C NMR spectra of the CMX-citrate synthase complex were obtained under a variety of sample conditions. Tensor values describing the chemical shift anisotropy of the carboxyl groups of the inhibitor were obtained by simulating MAS spectra (233 +/- 4, 206 +/- 5, and 105 +/- 2 ppm vs TMS). Comparison of these values with our previously reported database and ab initio calculations of carbon shift tensor values clearly indicates that the carboxyl is deprotonated. New data from model compounds suggest that hydrogen bonds in a syn arrangement with respect to the carboxylate group have a pronounced effect upon the shift tensors for the carboxylate, while anti hydrogen bonds, regardless of their length, apparently do not perturb the shift tensors of the carboxyl group. Thus the tensor values for the enzyme-inhibitor complex could be consistent with either a very long syn hydrogen bond or an anti hydrogen bond; the latter would agree very well with previous crystallographic results. Two-dimensional 1H-13C heteronuclear correlation spectra of the enzyme-inhibitor complex were obtained. Strong cross-peaks were observed from the carboxyl carbon to proton(s) with chemical shift(s) of 22 +/- 5 ppm. Both the proton chemical shift and the intensity of the cross-peak indicate a very short hydrogen bond to the carboxyl group of the inhibitor, the C.H distance based upon the cross-peak intensity being 2.0 +/- 0.4 A. This proton resonance is assigned to Hdelta2 of Asp 375, on the basis of comparison with crystal structures and the fact that this cross-peak was absent in the heteronuclear correlation spectrum of the inhibitor-D375G mutant enzyme complex. In summary, our NMR studies support the suggestion that a very short hydrogen bond is formed between the TSA and the Asp carboxylate.

PHA applications: addressing the price performance issue: I. Tissue engineering

This paper describes the development of medical applications for polyhydroxyalkanoates (PHAs), a class of natural polymers with a wide range of thermoplastic properties. Methods are described for preparing PHAs with high purity, modifying these materials to change their surface and degradation properties, and methods for fabricating them into different forms, including tissue engineering scaffolds. Preliminary reports characterizing their in vivo behavior are given, as well as methods for using the natural polymers in tissue engineering applications.

The Planetree Model Hospital Project: an example of the patient as partner

The Planetree Model Hospital Project at Pacific Presbyterian Medical Center in San Francisco uses a patient-centered philosophy to incorporate the patient as a partner in the care process. This article describes the Planetree unit and discusses two aspects of the program--training patients to be partners and increasing nurse satisfaction. Such programs have the potential for improving the health outcomes of patients and aiding hospitals by assuring quality of care with greater patient participation, by improving public relations, and by promoting staff satisfaction.

Musculoskeletal function assessment: reference values for patient and non-patient samples

Although researchers and clinicians are encouraged to use health-status questionnaires to evaluate, monitor, and modify care, their use is hindered by the lack of reference values. Without reference values, it is difficult to interpret or evaluate questionnaire scores. In this paper, we present reference values for the Musculoskeletal Function Assessment, a 101-item health-status questionnaire designed and validated for patients with a broad range of musculoskeletal disorders. We describe reference values for two samples: non-patients (n = 123) and patients with isolated extremity injuries (n = 274). For the non-patient sample, descriptive statistics are presented by age and gender, measured at one point in time. For the patient sample, descriptive statistics are provided for seven Orthopaedic Trauma Association/AO diagnostic groups, measured at two points in time. Reference values for changes in the Musculoskeletal Function Assessment total score are described for patients 3 and 9 months and 6 and 12 months after injury. The total scores by post-injury interval, across the diagnostic groups, are significantly better at follow-up than at baseline (p = 0.00). Reference values for changes in total scores are also described in terms of these diagnostic groups across post-injury intervals. Musculoskeletal Function Assessment total scores for Orthopaedic Trauma Association/AO diagnostic groups are significantly better at follow-up than at baseline (p < 0.03). Changes in the total score are also tested for responsiveness with use of standardized response means. Large effects are demonstrated for patients completing the Musculoskeletal Function Assessment at 3 and 9 months (1.03), and small effects are demonstrated for those completing it at 6 and 12 months (0.49). Moderate and large effects are demonstrated for Orthopaedic Trauma Association/AO diagnostic groups across post-injury intervals.

Mortality, health services use, and health behavior in a cohort of well older adults

OBJECTIVES

To construct an evidence-based Good Health Behavior Score and examine the relationship between aggregate health behaviors, mortality, and health services utilization in the last year of life in a cohort of well older adults.

DESIGN

A prospective cohort.

SETTING

A large health maintenance organization.

PARTICIPANTS

1867 older enrollees who responded to a health promotion survey.

MEASUREMENTS

A baseline self-administered questionnaire was used to ascertain health behaviors in 1987-1988, and vital status was determined 48 months later. A Good Health Behavior Score was calculated, and a Cox proportional hazards model was used to compare high, middle, and low score groups regarding risk of death. For those who died, differences in amount and type of health services utilization in relation to the summary score were compared for the year before death.

RESULTS

During the 4 years of follow-up, the mortality rate for the mid-level score group was 50% less, and in the highest score group was 70% less, than in the lowest score group. Among decedents, no significant differences were found between high and low Good Health Behavior score groups for inpatient and outpatient utilization, pharmacy use, or total cost during the last year of life.

CONCLUSION

An easily developed and simple health behavior score can predict short term mortality quite strongly. Medical care costs in the last year of life were similar in individuals with higher and lower health behavior scores.

State-sponsored programs for the uninsured: is there adverse selection?

Risk contracting by states for coverage of previously uninsured populations has been hampered by uncertainty regarding likely claims experience. This study reports on the utilization experience of two state programs offering subsidized coverage in commercial managed care organizations to low-income and previously uninsured people. Program participants used services similarly to people enrolled through large employer benefit plans. There was no evidence of pent-up demand or an unusual level of chronic illness. Similarly, there was little evidence of underutilization, although dissatisfaction and reported barriers to service were more frequent among nonwhite enrollees.

Health consequences of pregnancy and childbirth as perceived by women and clinicians

OBJECTIVE

To develop patient-centered outcome measures for clinical research by characterizing the effects of pregnancy and childbirth on functioning.

METHODS

Five focus groups of mothers (n = 33) and three focus groups of clinicians (midwives [n = 8], obstetricians [n = 4], and family practitioners [n = 7]) were convened. Discussions were audiotaped and transcribed. Major narrative themes were identified by using two independent readers and were confirmed by participants and additional clinicians.

RESULTS

Themes were grouped into four outcome domains: physical, psychologic, sexual, and social. Themes identified included lack of knowledge about postpartum health, emotional lability, sexual satisfaction, depression, parenting skills, body image, fatigue, and incontinence. Lack of knowledge about typical postpartum health was the dominant theme for mothers and clinicians. Mothers felt unprepared for the health consequences of pregnancy and delivery. Clinicians lamented that paucity of data made counseling and treating patients difficult. Decreased functioning months after delivery was reported. Differences between mother and clinician concerns surfaced, particularly in emphasis. Mothers wanted more information about their health; providers emphasized newborn care. Mothers reported inspiration to improve their economic circumstances; clinicians emphasized improving maternal health. Mothers wanted control during labor, whereas clinicians believed control was not always possible.

CONCLUSION

Women often felt poorly prepared for the postpartum period in part because functional health consequences are not well understood. This study suggests maternal functional health may be decreased for months after delivery, even among uncomplicated patients. This study identified new maternal outcome measures, which are being incorporated into an outcomes questionnaire.

Clinical experience with image-guided robotic radiosurgery (the Cyberknife) in the treatment of brain and spinal cord tumors

The Cyberknife is an image-guided "frameless" dedicated radiosurgical device. This instrument has several distinct advantages over frame-based systems, including improved patient comfort, increased treatment degrees of freedom, and the potential to target extracranial lesions. Clinical results thus far with respect to the treatment of malignant intracranial tumors has been promising. Additionally, the Cyberknife will likely revolutionize the application of radiosurgery to extracranial sites. A description of the components, treatment planning, and clinical results of the Cyberknife will be reviewed.

Acute hearing loss following fractionated stereotactic radiosurgery for acoustic neuroma. Report of two cases

Two cases of acute hearing loss are reported following fractionated stereotactic radiosurgery for acoustic neuroma. Both patients had neurofibromatosis type 2 and were treated with a peripheral tumor dose of 21 Gy delivered in three fractions (7 Gy each) with a minimum interfraction interval of 10 hours. One patient who had previously undergone surgical resection of the treated tumor presented with only rudimentary hearing in the treated ear secondary to an abrupt decrease in hearing prior to treatment. That patient reported total loss of hearing before complete delivery of the third fraction. The second patient had moderately impaired hearing prior to treatment; however, within 10 hours after delivery of the final fraction, he lost all hearing. Both patients showed no improvement in response to glucocorticoid therapy. Possible explanations for this phenomenon are presented.

Stereotactic radiosurgery of angiographically occult vascular malformations: 14-year experience

OBJECTIVE

Radiosurgery is generally effective in obliterating true arteriovenous malformations, but less is known about its effects on angiographically occult vascular malformations (AOVMs). Since July 1983, 57 patients with surgically inaccessible AOVMs of the brain were treated using helium ion (47 patients) or linear accelerator (10 patients) radiosurgery. This study retrospectively evaluates the response of these AOVMs to treatment.

METHODS

All patients presented with previous hemorrhage. The mean patient age was 35.6 years (range, 13-71 yr). The mean AOVM volume was 2.25 cm3 (range, 0.080-15.2 cm3), treated with a mean of 18.0 Gy equivalent (physical dose x relative biological effectiveness, which is 1.3 for helium ion Bragg peak) (range, 7.0-40 Gy equivalent). The Drake scale scores before treatment were as follows: excellent (25 patients), good (26 patients), and poor (6 patients). The mean follow-up period was 7.5 years (range, 9 mo-13.8 yr).

RESULTS

Eighteen patients (32%) bled symptomatically (20 hemorrhages) after radiosurgery. Sixteen hemorrhages occurred within 36 months after radiosurgery (9.4% annual bleed rate; 16 hemorrhages/171 patient yr); 4 hemorrhages occurred more than 36 months after treatment (1.6% annual bleed rate; 4 hemorrhages/257 patient yr) (P < 0.001). Complications included symptomatic radiation edema (four patients, 7%), necrosis (one patient, 2%), and increased seizure frequency (one patient, 2%). Eight patients underwent surgical resection of their AOVMs 8 to 59 months after radiosurgery because of subsequent hemorrhage. The Drake scale scores after treatment were as follows: excellent (25 patients), good (24 patients), poor (3 patients), and dead (5 patients, 3 of whom died as a result of causes unrelated to the AOVMs or radiosurgery).

CONCLUSION

Radiosurgery may be useful for AOVMs located in surgically inaccessible regions of the brain. A significant decrease in bleed rate exists more than 3 years after treatment compared with the bleed rate within 3 years of treatment. Because current neuroradiological techniques are not able to image obliterative response in these slow-flow vascular lesions, longer term clinical follow-up is required.

Treatment of hemangioblastomas in von Hippel-Lindau disease with linear accelerator-based radiosurgery

OBJECTIVE

Stereotactic radiosurgery is increasingly being used to treat hemangioblastomas, particularly those that are in surgically inaccessible locations or that are multiple, as is common in von Hippel-Lindau disease. The purpose of this study was to retrospectively evaluate the effectiveness of radiosurgery in the treatment of hemangioblastomas.

METHODS

From 1989 to 1996, 29 hemangioblastomas in 13 patients with von Hippel-Lindau disease were treated with linear accelerator-based radiosurgery. The mean patient age was 40 years (range, 31-57 yr). The radiation dose to the tumor periphery averaged 23.2 Gy (range, 18-40 Gy). The mean tumor volume was 1.6 cm3 (range, 0.07-65.4 cm3). Tumor response was evaluated in serial, contrast-enhanced, computed tomographic and magnetic resonance imaging scans. The mean follow-up period was 43 months (range, 11-84 mo).

RESULTS

Only one (3%) of the treated hemangioblastomas progressed. Five tumors (17%) disappeared, 16 (55%) regressed, and 7 (24%) remained unchanged in size. Five of nine patients with symptoms referable to treated hemangioblastomas experienced symptomatic improvement. During the follow-up period, one patient died as a result of progression of untreated hemangioblastomas in the cervical spine. Three patients developed radiation necrosis, two of whom were symptomatic.

CONCLUSION

Although follow-up monitoring is limited, stereotactic radiosurgery provides a high likelihood of local control of hemangioblastomas and is an attractive alternative to multiple surgical procedures for patients with von Hippel-Lindau disease.

Randomized trial of a patient-centered hospital unit

Patient-centered hospital units have grown out of the national trend to greater consumerism, but few of these units have been evaluated rigorously. We used a randomized controlled trial to compare patient outcomes on the Planetree Model Hospital Unit with other medical-surgical units in the hospital. Planetree patients were significantly more satisfied than controls with their hospital stay, the unit's environment and nursing care, but did not differ in ratings of physician care. Planetree patients reported more involvement in their care while hospitalized and higher satisfaction with the education they received. There were few differences between Planetree and controls in health behaviors. While Planetree patients reported better mental health status and role functioning after discharge, their health status was similar to controls after 3 to 6 months. There were no differences in length of stay and charges for the index hospitalization, readmissions or outpatient care during the following year.

Microcomputer-Based Quantification of Maize Streak Virus Symptoms in Zea mays

ABSTRACT We investigated the use of computer-assisted image analysis techniques for the objective quantification of maize streak virus (MSV) symptoms in Zea mays. We compared independent duplicate evaluations of chlorotic lesion areas occurring on MSV-infected leaves using visual assessment, a commercial image analysis system, and a custom image analysis system employing software developed in our laboratory. Relative to visual assessments of disease severity, computer-assisted image analysis employing both the commercial and custom systems provided significant enhancements in the accuracy and precision of chlorotic area estimations. The commercial image analysis system afforded no significant improvement in precision or accuracy over the custom system. An important advantage of examining images using the custom-written software was that the software permitted a high degree of analysis automation. Digitized images of maize leaves could be automatically analyzed by the custom software five times faster than, and with the same precision and accuracy as, when the same images were analyzed with the commercial software. Because of the flexibility of the image analysis techniques described, they should be applicable to the measurement of symptom severity in other plant host-pathogen combinations.

Comparison of length of stay for asthma by hospital type

OBJECTIVE

To determine whether length of stay (LOS) for asthma admissions at a local university-affiliated children's hospital (UACH) is similar to that of community hospitals within the same county.

METHODS

A retrospective analysis was performed using computerized hospital abstract records from 1989 through 1994. The study population was children 1 to 18 years old whose first or only hospitalization for a primary diagnosis of asthma occurred during the study period at either the UACH or one of the 17 community hospitals in King County, WA, that admit pediatric patients (n = 2491). Transfers and patients with chronic obstructive asthma or secondary diagnoses such as cystic fibrosis were not included in the study. Asthma patients were compared by sociodemographic and health risk characteristics such as age, sex, insurance status, and a comorbidity severity score. Differences between the two hospital populations were tested by chi2 and t tests. The effect of hospitalization at the UACH or the community hospitals on LOS was determined using analysis of covariance after adjusting for the sociodemographic and health risk covariates.

RESULTS

Sixty-two percent (62%) of the asthma patients in the study population were discharged from the UACH. Compared with patients discharged from the community hospitals, the UACH patients were significantly younger, more often male, used public insurance, and resided in areas with lower median household incomes. The severity of comorbidities was not different between the two hospital groups. Overall, adjusted mean LOS was not significantly longer at the UACH (2.1 days) than at the community hospitals (2.0 days); however, adjusted mean LOS for specific subgroups, most notably poor children and those with public insurance, was significantly longer at the UACH.

CONCLUSION

LOS for first or only asthma hospitalizations during 1989 through 1994 at the UACH was similar to local community hospitals within the same county. Specific subgroups of children were hospitalized for a longer period at the UACH, but children with private insurance and from areas with higher median household incomes had similar LOS, and presumably costs, at the UACH and the community hospitals.

A randomized controlled trial of CQI teams and academic detailing: can they alter compliance with guidelines?

BACKGROUND

The availability of clinical guidelines in isolation has generally failed to promote voluntary change in practice patterns. Accordingly, a randomized controlled trial was conducted to determine the effectiveness of academic detailing (AD) techniques and continuous quality improvement (CQI) teams in increasing compliance with national guidelines for the primary care of hypertension and depression.

METHODS

Fifteen small group practices at four Seattle primary care clinics were assigned to one of three study arms--AD alone, AD plus CQI teams, or usual care. The activity of 95 providers and 4,995 patients was monitored from August 1, 1993, through January 31, 1996. Twelve-month baseline and study periods were separated by a six-month "wash-in" period during which training sessions were held. Changes in hypertension prescribing, blood pressure control, depression recognition, use of older tricyclics, and scores on the Hopkins Symptom Checklist depression scale were examined.

RESULTS

Clinics varied considerably in their implementation of both the AD and the CQI team interventions. Across all sites, AD was associated with change in a single process measure, a decline in the percentage of depressives prescribed first-generation tricyclics (-4.7 percentage points versus control, p = 0.04). No intervention effects were demonstrated for CQI teams across all sites for either disease condition. Within the clinic independently judged most successful at implementing both change strategies, the use of CQI teams and AD in combination did increase the percentage of hypertensives adequately controlled (17.3 percentage points versus control, p = 0.03).

SUMMARY AND CONCLUSIONS

The AD techniques and the CQI teams evaluated were generally ineffective in improving guideline compliance and clinical outcomes regarding the primary care of hypertension and depression.