Synthesis and Biopharmaceutical Characterization of Amphiphilic Squalenyl Derivative Based Versatile Drug Delivery Platform

Limited drug loading capacity (LC), mostly below 5% w/w, is a significant drawback of nanoparticulate drug delivery systems (DDS). Squalenoylation technology, which employs bioconjugation of squalenyl moiety and drug, allows self-assemble of nanoparticles (NPs) in aqueous media with significantly high LC (>30% w/w). The synthesis and particle preparation of squalenoylated prodrugs are, however, not facile for molecules with multiple reactive groups. Taking a different approach, we describe the synthesis of amphiphilic squalenyl derivatives (SqDs) as well as the physicochemical and biopharmaceutical characterizations of their self-assembled NPs as DDSs. The SqDs included in this study are (i) cationic squalenyl diethanolamine (ii) PEGylated SqD (PEG 750 Da), (iii) PEGylated SqD (PEG 3,000 Da), and (iv) anionic squalenyl hydrogen sulfate. All four SqDs self-assemble into NPs in a size range from 100 to 200 nm in an aqueous solution. Furthermore, all NP derivatives demonstrate appropriate biocompatibility and adequate colloidal stability in physiological relevant pH environments. The mucoprotein binding of PEGylated NPs is reduced compared to the charged NPs. Most importantly, this technology allows excellent LC (at maximum of 45% w/w) of a wide range of multifunctional compounds, varying in physicochemical properties and molecular weight. Interestingly, the drug release profile can be tuned by different loading methods. In summary, the SqD-based NPs appear as versatile drug delivery platforms.

Itaconic Acid Increases the Efficacy of Tobramycin against Pseudomonas aeruginosa Biofilms

The search for novel therapeutics against pulmonary infections, in particular Pseudomonas aeruginosa (PA) biofilm infections, has been intense to deal with the emergent rise of antimicrobial resistance. Despite the numerous achievements in drug discovery and delivery strategies, only a limited number of therapeutics reach the clinic. To allow a timely preclinical development, a formulation should be highly effective, safe, and most importantly facile to produce. Thus, a simple combination of known actives that enhances the therapeutic efficacy would be a preferential choice compared to advanced drug delivery systems. In this study, we propose a novel combination of an anti-inflammatory agent-itaconic acid (itaconate, IA)-and an approved antibiotic-tobramycin (Tob) or ciprofloxacin (Cipro). The combination of Tob and IA at a molar ratio of 1:5 increased the biofilm eradicating efficacy in the strain PA14 wild type (wt) by ~4-fold compared to Tob alone. In contrast, such effect was not observed for the combination of IA with Cipro. Subsequent studies on the influence of IA on bacterial growth, pyocyanin production, and Tob biofilm penetration indicated that complexation with IA enhanced the transport of Tob through the biofilm. We recommend the simple and effective combination of Tob:IA for further testing in advanced preclinical models of PA biofilm infections.

Squalenyl Hydrogen Sulfate Nanoparticles for Simultaneous Delivery of Tobramycin and an Alkylquinolone Quorum Sensing Inhibitor Enable the Eradication of P. aeruginosa Biofilm Infections

Elimination of pulmonary Pseudomonas aeruginosa (PA) infections is challenging to accomplish with antibiotic therapies, mainly due to resistance mechanisms. Quorum sensing inhibitors (QSIs) interfering with biofilm formation can thus complement antibiotics. For simultaneous and improved delivery of both active agents to the infection sites, self‐assembling nanoparticles of a newly synthesized squalenyl hydrogen sulfate (SqNPs) were prepared. These nanocarriers allowed for remarkably high loading capacities of hydrophilic antibiotic tobramycin (Tob) and a novel lipophilic QSI at 30 % and circa 10 %, respectively. The drug‐loaded SqNPs showed improved biofilm penetration and enhanced efficacy in relevant biological barriers (mucin/human tracheal mucus, biofilm), leading to complete eradication of PA biofilms at circa 16‐fold lower Tob concentration than Tob alone. This study offers a viable therapy optimization and invigorates the research and development of QSIs for clinical use.

PLGA nanocapsules improve the delivery of clarithromycin to kill intracellular Staphylococcus aureus and Mycobacterium abscessus

Drug delivery systems are promising for targeting antibiotics directly to infected tissues. To reach intracellular Staphylococcus aureus and Mycobacterium abscessus, we encapsulated clarithromycin in PLGA nanocapsules, suitable for aerosol delivery by nebulization of an aqueous dispersion. Compared to the same dose of free clarithromycin, nanoencapsulation reduced 1000 times the number of intracellular S. aureus in vitro. In RAW cells, while untreated S. aureus was located in acidic compartments, the treated ones were mostly situated in non-acidic compartments. Clarithromycin-nanocapsules were also effective against M. abscessus (70-80% killing efficacy). The activity of clarithromycin-nanocapsules against S. aureus was also confirmed in vivo, using a murine wound model as well as in zebrafish. The permeability of clarithromycin-nanocapsules across Calu-3 monolayers increased in comparison to the free drug, suggesting an improved delivery to sub-epithelial tissues. Thus, clarithromycin-nanocapsules are a promising strategy to target intracellular S. aureus and M. abscessus.

Kinetics of mRNA delivery and protein translation in dendritic cells using lipid-coated PLGA nanoparticles

BACKGROUND

Messenger RNA (mRNA) has gained remarkable attention as an alternative to DNA-based therapies in biomedical research. A variety of biodegradable nanoparticles (NPs) has been developed including lipid-based and polymer-based systems for mRNA delivery. However, both systems still lack in achieving an efficient transfection rate and a detailed understanding of the mRNA transgene expression kinetics. Therefore, quantitative analysis of the time-dependent translation behavior would provide a better understanding of mRNA's transient nature and further aid the enhancement of appropriate carriers with the perspective to generate future precision nanomedicines with quick response to treat various diseases.

RESULTS

A lipid-polymer hybrid system complexed with mRNA was evaluated regarding its efficiency to transfect dendritic cells (DCs) by simultaneous live cell video imaging of both particle uptake and reporter gene expression. We prepared and optimized NPs consisting of poly (lactid-co-glycolid) (PLGA) coated with the cationic lipid 1, 2-di-O-octadecenyl-3-trimethylammonium propane abbreviated as LPNs. An earlier developed polymer-based delivery system (chitosan-PLGA NPs) served for comparison. Both NPs types were complexed with mRNA-mCherry at various ratios. While cellular uptake and toxicity of either NPs was comparable, LPNs showed a significantly higher transfection efficiency of ~ 80% while chitosan-PLGA NPs revealed only ~ 5%. Further kinetic analysis elicited a start of protein translation after 1 h, with a maximum after 4 h and drop of transgene expression after 48 h post-transfection, in agreement with the transient nature of mRNA.

CONCLUSIONS

Charge-mediated complexation of mRNA to NPs enables efficient and fast cellular delivery and subsequent protein translation. While cellular uptake of both NP types was comparable, mRNA transgene expression was superior to polymer-based NPs when delivered by lipid-polymer NPs.

In Vitro Model of the Gram-Negative Bacterial Cell Envelope for Investigation of Anti-Infective Permeation Kinetics

The cell envelope of Gram-negative bacteria is a formidable biological barrier, inhibiting the action of antibiotics by impeding their permeation into the intracellular environment. In-depth understanding of permeation through this barrier remains a challenge, despite its critical role in antibiotic activity. We therefore designed a divisible in vitro permeation model of the Gram-negative bacterial cell envelope, mimicking its three essential structural elements, the inner membrane and the periplasmic space as well as the outer membrane, on a Transwell setup. The model was characterized by contemporary imaging techniques and employed to generate reproducible quantitative and time-resolved permeation data for various fluorescent probes and anti-infective molecules of different structure and physicochemical properties. For a set of three fluorescent probes, the permeation through the overall membrane model was found to correlate with in bacterio permeation. Even more interestingly, for a set of six Pseudomonas quorum sensing inhibitors, such permeability data were found to be predictive for their corresponding in bacterio activities. Further exploration of the capabilities of the overall model yielded a correlation between the permeability of porin-independent antibiotics and published in bacterio accumulation data; a promising ability to provide structure-permeability information was also demonstrated. Such a model may therefore constitute a valuable tool for the development of novel anti-infective drugs.

Starch-Chitosan Polyplexes: A Versatile Carrier System for Anti-Infectives and Gene Delivery

Despite the enormous potential of nanomedicine, the search for materials from renewable resources that balance bio-medical requirements and engineering aspects is still challenging. This study proposes an easy method to make nanoparticles composed of oxidized starch and chitosan, both isolated from natural biopolymers. The careful adjustment of C/N ratio, polymer concentration and molecular weight allowed for tuning of particle characteristics. The system's carrier capability was assessed both for anti-infectives and for nucleic acid. Higher starch content polyplexes were found to be suitable for high encapsulation efficiency of cationic anti-infectives and preserving their bactericidal function. A cationic carrier was obtained by coating the anionic polyplex with chitosan. Coating allowed for a minimal amount of cationic polymer to be employed and facilitated plasmid DNA loading both within the particle core and on the surface. Transfection studies showed encouraging result, approximately 5% of A549 cells with reporter gene expression. In summary, starch-chitosan complexes are suitable carriers with promising perspectives for pharmaceutical use.

Polysaccharide Submicrocarrier for Improved Pulmonary Delivery of Poorly Soluble Anti-infective Ciprofloxacin: Preparation, Characterization, and Influence of Size on Cellular Uptake

The majority of the currently used and developed anti-infectives are poorly water-soluble molecules. The poor solubility might lead to limited bioavailability and pharmacological action of the drug. Novel pharmaceutical materials have thus been designed to solve those problems and improve drug delivery. In this study, we propose a facile method to produce submicrocarriers (sMCs) by electrostatic gelation of anionic ß-cyclodextrin (aß-CD) and chitosan. The average hydrodynamic size ranged from 400 to 900 nm by carefully adjusting polymer concentrations and N/C ratio. The distinct host-guest reaction of cyclodextrin derivative is considered as a good approach to enhance solubility, and prevent drug recrystallization, and thus was used to develop sMC to improve the controlled release profile of a poorly soluble and clinically relevant anti-infective ciprofloxacin. The optimal molar ratio of ciprofloxacin to aß-CD was found to be 1:1, which helped maximize encapsulation efficiency (∼90%) and loading capacity (∼9%) of ciprofloxacin loaded sMCs. Furthermore, to recommend the future application of the developed sMCs, the dependence of cell uptake on sMCs size (500, 700, and 900 nm) was investigated in vitro on dTHP-1 by both flow cytometry and confocal microscopy. The results demonstrate that, regardless of their size, an only comparatively small fraction of the sMCs were taken up by the macrophage-like cells, while most of the carriers were merely adsorbed to the cell surface after 2 h incubation. After continuing the incubation to reach 24 h, the majority of the sMCs were found intracellularly. However, the sMCs had been designed to release sufficient amount of drug within 24 h, and the subsequent phagocytosis of the carrier may be considered as an efficient pathway for its safe degradation and elimination. In summary, the developed sMC is a suitable system with promising perspectives recommended for pulmonary extracellular infection therapeutics.

The bacterial cell envelope as delimiter of anti-infective bioavailability - An in vitro permeation model of the Gram-negative bacterial inner membrane

Gram-negative bacteria possess a unique and complex cell envelope, composed of an inner and outer membrane separated by an intermediate cell wall-containing periplasm. This tripartite structure acts intrinsically as a significant biological barrier, often limiting the permeation of anti-infectives, and so preventing such drugs from reaching their target. Furthermore, identification of the specific permeation-limiting envelope component proves difficult in the case of many anti-infectives, due to the challenges associated with isolation of individual cell envelope structures in bacterial culture. The development of an in vitro permeation model of the Gram-negative inner membrane, prepared by repeated coating of physiologically-relevant phospholipids on Transwell^® filter inserts, is therefore reported, as a first step in the development of an overall cell envelope model. Characterization and permeability investigations of model compounds as well as anti-infectives confirmed the suitability of the model for quantitative and kinetically-resolved permeability assessment, and additionally confirmed the importance of employing bacteria-specific base materials for more accurate mimicking of the inner membrane lipid composition - both advantages compared to the majority of existing in vitro approaches. Additional incorporation of further elements of the Gram-negative bacterial cell envelope could ultimately facilitate model application as a screening tool in anti-infective drug discovery or formulation development.

Accessibility of primary care physicians' offices for people with disabilities. An analysis of compliance with the Americans With Disabilities Act

OBJECTIVE

To determine if primary care physicians are in compliance with the Americans With Disabilities Act of 1990 (ADA) and to what extent offices of primary care physicians are usable for persons with disabilities.

DESIGN

Cross-sectional survey.

SETTING

Members listed in the Harris County (Texas) Medical Society roster.

SUBJECTS

Sixty-two general practitioners, family practitioners, internists, and obstetrician-gynecologists.

MAIN OUTCOME MEASURE

A 15-page questionnaire with 57 items and 136 variables.

RESULTS

Eleven (18%) of the primary care physicians in this study were unable to serve their patients with disabilities in the last year for reasons that could be interpreted as noncompliant with the ADA. Two physicians (3%) had offices that patients with disabilities could not enter because of physical barriers, and 1 physician (2%) had inaccessible equipment. Fourteen physicians (22%) were improperly referring patients with disabilities although they generally treat such patients. In measuring the level of compliance with regard to structural features that enhance the accessibility of the physicians' offices, only 8 (13%) had a low level of compliance. Thirty-nine (63%) of the physicians supplied auxiliary aids and services to their patients with disabilities. The most common aid was printed materials.

CONCLUSIONS

A substantial portion of primary care physicians' offices are not in compliance with the ADA, and some informational tools will be required to inform physicians about the nondiscriminatory requirements of the statute.

Predicting acute denervation in carpal tunnel syndrome

OBJECTIVE

To determine which nerve conduction parameters can predict the presence of acute denervation in carpal tunnel syndrome.

SETTING

The electrodiagnostic laboratories of a hospital and a county hospital district.

DESIGN

A retrospective review.

PATIENTS

A total of 1,590 consecutive cases from January 1992 to June 1996, diagnosed as having median neuropathy at the wrist.

MAIN OUTCOME MEASURES

Evidence of acute denervation on needle electromyography of the abductor pollicis brevis and its relationship to patient age, gender, and parameters obtained from nerve conduction studies, including median sensory latency and amplitude, and median motor latency and amplitude.

RESULTS

Logistic regression analysis identified gender, median motor latency, and median motor amplitude (all p < or = .008) as contributing to the prediction of denervation. Needle examination of the cases with a median motor amplitude <7 mV detected 95.3% (141/148) of all cases with denervation and could have spared 52% (708/1,362) of the population from a needle examination of the abductor pollicis brevis.

CONCLUSION

The median motor amplitude can predict the presence of acute denervation in the thenar muscles in median neuropathy at the wrist and possibly eliminate a painful needle examination of the median-innervated thenar muscles in over 50% of the cases.

Functional outcomes of patients on a rehabilitation unit after open heart surgery

BACKGROUND

Compared with predecessors, the modern-day patient who undergoes cardiac surgery is sicker, is older, has more diffuse disease, has poorer ventricular function, and is more likely to be a repeat surgery. Patients hospitalized after open heart surgery in the 1990s, therefore, may require increasingly comprehensive rehabilitation services before returning to the community; however, information documenting functional progress during, and outcome after, a hospital-based rehabilitation program is scarce.

METHODS

During a 14-month period, a consecutive sample of 44 patients who underwent cardiac surgery and were admitted to a rehabilitation unit in a tertiary acute hospital was studied. Thirty-one patients had coronary artery bypass graft, six had valvular surgery, and seven had both. Each patient's functional status on admission and discharge from the rehabilitation unit was assessed using the Functional Independence Measure. Other data studied included patient age and sex, premorbid medical problems, type of cardiac surgery, length of stay, and occurrence of medical complications in the acute and rehabilitation units.

RESULTS

The mean Functional Independence Measure scores at rehabilitation unit admission and discharge were 76.1 +/- 17.1 and 96.7 +/- 19.4, respectively, and this difference was significant (P < 0.0001). The most significant correlates (alpha = 0.05) of the discharge Functional Independence Measure were admission Functional Independence Measure (P < 0.00001) and length of stay in the acute care unit (P = 0.0072). Age and presence of medical complications were not significant.

CONCLUSION

Patients who undergo open heart surgery, many of whom have medical comorbidity, are able to demonstrate substantial functional improvement on an inpatient rehabilitation program before hospital discharge.

Analysis of gram negative recolonization of the neuropathic bladder among patients with spinal cord injuries

Over a 4 year period, 119 acute spinal cord injury (SCI) patients were enrolled in this study. The 101 males and 18 females had a mean age of 35.9 years (range 16-87). Sixty-two patients were tetraplegic and 57 were paraplegic. All patients had a urine specimen taken for culture, colony count and sensitivity once weekly while they were receiving intermittent catheterization. Of these, 22 patients (18.5%), none of whom had underlying genito-urinary (GU) pathology, developed recolonization by an organism of the same species and genus previously cultured. All 22 reached sterile-urine between colonizations after being treated with antibiotics for at least 7 days. The 16 males and six females had a mean age of 35.1 years (range 17-79). Sixteen were tetraplegic and six were paraplegic. Plasmid analysis (PA) was used to determine whether these recolonizations were from the same or from a different strain. In those instances where the bacteria harbored no plasmids or where the results of plasmid analysis were otherwise inconclusive, bacteria were also compared using restriction fragment length polymorphism (RFLP) analysis. Recolonization was caused primarily by E. coli and K. pneumoniae. While there was no significant difference between the two organisms with respect to the number of days when sterile urine occurred to the time when recolonization was observed, there were significant differences seen in both organisms with regard to the time lapse from one colonization to the next: the average number of days to recolonization with an identical organism was 10.3 days, whereas with a different strain it was 15.9 days (P < 0.04). When a different organism was cultured between the recolonizations, the mean recolonization interval was 17.9 days. When no intervening organism occurred, the interval was 9.5 days (P < 0.005). Both intervals measured the days from the first sterile urine after the first colonization to the next colonization. These data indicate the proclivity for two common Gram negative normal bowel inhabitants to recolonize the neuropathic bladder of spinal cord injured patients even after adequate treatment. PA and RFLP provide a means of discriminating between relapses by the same organism versus recurrences by a different organism of the same species and genus. Those with the same identity tend to recur sooner than those of different identities and may be suspected when relapse occurs within two weeks of cessation of 7 day course of antibiotics. While an intervening organism may delay the relapse (or recurrence), it does not prevent it and identical organisms can reappear even after adequate therapeutic regimens. Since none of the patients in this study had GU pathology, recolonization by an identical strain (relapse) does not necessarily warrant an extensive investigation for disease within the GU tract.

Reported pressure ulcer prevention and management techniques by persons with spinal cord injury

OBJECTIVE

The purpose of this study was to identify factors that resulted in severe pressure ulcers in a community-based sample of 23 persons with spinal cord injury (SCI).

DESIGN

A correlational design was used.

SUBJECTS

Twenty men and three women, 57% with tetraplegia and 43% with paraplegia, participated. Adult participants with an ulcer of 12 weeks' duration or less were recruited from the plastic surgery clinic of a regional SCI center.

MEASURES

A structured survey assessed demographic, SCI and ulcer characteristics; detection method; immediacy and appropriateness of action; time from detection to clinic visit; number of prior ulcers; and knowledge and practice of ulcer prevention techniques. Ulcer characteristics (ie, location, size, and stage) were assessed by examination and compared with participants' descriptions of their ulcers.

RESULTS

Severe ulcers and ulcers that progressed in severity after initial detection were less accurately described by participants. Individuals who waited longer to come to the clinic presented with more severe ulcers. Taking immediate or appropriate action when an ulcer was detected was related to reported performance of more preventive behaviors. Contrary to expectation, immediacy and appropriateness of action, and knowledge and practice of preventive behaviors were unrelated to severity, progression of severity, and time from detection to the clinic visit. The findings suggest that educational programs should emphasize more strongly immediate visits to a physician upon detection of an ulcer. Furthermore, such educational models should be assessed for their effectiveness in reducing ulcers and preventing progression in severity once persons with SCI return to the community.

Alcohol and marijuana use in a community-based sample of persons with spinal cord injury

The prevalence of self-reported alcohol and marijuana use, along with alcohol abuse as measured by the Short Michigan Alcoholism Screening Test, was assessed for a community-based sample (n = 123) of persons with spinal cord injury (SCI). Correlates of alcohol and marijuana use and alcohol abuse also were examined, including demographic variables, measures of impairment, disability, and handicap, SCI medical complications, and measures of subjective assessment such as health rating, health maintenance behaviors, depression, life satisfaction, perceived stress, pain, and social support. Prevalence of alcohol use (59%) and marijuana use (16%) in persons with SCI was less than that of comparison groups in the general population. However, prevalence of alcohol abuse (21%) exceeded that of general population studies. Participants who abused alcohol shared the following criteria: (1) perceived their overall health as worse than those who did not abuse alcohol; (2) were more depressed; and (3) experienced more stress in their lives than those who did not abuse alcohol. Participants who used marijuana were younger at the time of the study and were younger at injury. They were also more depressed and more stressed. The indications of alcohol abuse in one in five persons with SCI living in the community mandates that screening, treatment, and referrals be part of any rehabilitation treatment program.

Intrathecal baclofen: does tolerance occur?

Concern over the development of tolerance in patients on continuous intrathecal baclofen therapy has arisen as this new form of treatment for spasticity has gained wider use. We have studied time-dose relationships in 18 spinal cord injured patients who have undergone intrathecal baclofen infusion pump implantation since February 1988 in our facility. Our data show that there was a significant increase in baclofen dosage needed to control spasticity during the first 12 months post implantation. After 12 months, however, no significant changes in dosage requirement was detected. In addition, there was no significant difference between completely and incompletely spinal cord injured patients with regard to both the initial dose and the tolerance trend.

Hypotensive anesthesia for scoliosis surgery in Jehovah's Witnesses

Hypotensive anesthesia has been advocated in spinal surgery for the purpose of diminishing operative blood loss. This study evaluated its effectiveness in 12 Jehovah's Witnesses undergoing Harrington instrumentation and fusion who refused transfusion. Previous series from this institute did not use deliberate hypotension because of routinely low blood loss. Compared with matched controls operated on under normotensive anesthesia, the Jehovah's Witness patients had lower absolute blood loss but also shorter operative time. Applied linear-regression analysis demonstrated that the diminished blood loss was associated with shorter operative time (P = 0.0002) rather than lower blood pressure. The majority of blood losses in spinal instrumentation with fusion occurs with decortication. This rapid bleeding occurs at venous pressures which are unaffected by arterial blood pressure manipulation. The authors conclude that spinal surgery is possible in Jehovah's Witnesses without transfusion and that operative technique is the single most important determinant of blood loss.

Clonidine effect on spasticity: a clinical trial

Clonidine was used as an adjunct to baclofen in 55 patients with spasticity due to spinal cord injury. Dosage was held at the minimum effect amount for those who responded. No effect was seen in 24 patients (44%), although 31 (56%) benefitted from the drug. Patients were grouped as quadriplegics or paraplegics, having complete or incomplete lesions. Of all quadriplegics, seven of 11 complete (64%) and 17 of 25 incomplete patients (68%) responded; among the paraplegics, six of 15 complete (40%) and one of four incomplete patients (25%) improved. Side effects were limited to postural hypotension necessitating reduction in dosage in three patients that were successfully treated; in the unsuccessfully treated group, one patient had insomnia, one had dizziness, and one had drowsiness.

Vocational development following severe spinal cord injury: a longitudinal study

Vocational development of individual with spinal cord injury was studied from shortly after injury to two years after discharge from inpatient rehabilitation. Objectives included examining differences in the course of vocational development by level of functional independence, and predicting vocational outcomes two years after injury. Thirty-three spinal cord injury patients (17 quadriplegics, 16 paraplegics) were followed during the study. The Goldberg Scale of Vocational Development was used to measure changes in vocational development over time. The Barthel Index was used to measure level of functional independence. Results revealed that vocational development was markedly depressed during initial inpatient rehabilitation and for six months after injury. Gradual improvement occurred after six months, but two years after discharge the level of vocational development remained lower than that before injury. Changes in vocational development over time did not differ significantly by level of functional independence. Best predictors of successful vocational outcomes were educational attainment, educational plans made before injury, and origin of interests in work.

Postdischarge outcomes for ventilator-dependent quadriplegics

Based on data contributed to the National Spinal Cord Injury Data Base between the years 1975 and 1981, outcomes were assessed for 34 patients who had been injured approximately a year earlier and who were ventilator dependent when discharged from inpatient rehabilitation. Their outcomes were compared with those of 196 patients who required mechanical respiration some time during acute care or rehabilitation, but who were free of such assistance at discharge. Statistically significant differences were obtained between the groups in levels of spinal cord injury, duration of acute care hospitalization, duration of total hospitalization, extent of self-care capability, hours/week of hired attendant care, and hours of actual physical assistance/day. The groups did not differ significantly in terms of duration of inpatient rehabilitation, duration of rehospitalization, and vocational or prevocational status at follow-up.

Results of a survey of 201 polio survivors

We present the results of a survey on the late effects of poliomyelitis in 201 persons. The most common new problems were fatigue, weakness in previously affected and unaffected muscles, muscle pain, and joint pain. The median time from poliomyelitis to onset of new problems ranged from 30 to 40 years. Factors at onset of polio most strongly associated with development of these late effects of polio were (1) hospitalization (P less than 0.00001), (2) age greater than 10 years (P less than 0.00001), (3) ventilator use (P less than 0.0029), and (4) paralytic involvement of all four limbs (P less than 0.0240). The differential diagnosis of these new problems, implications for treatment, and areas for future research are discussed.

New problems in old polio patients: results of a survey of 539 polio survivors

Presented are the results of a questionnaire survey on new health problems in 539 polio survivors. The most common new problems were fatigue, weakness in previously affected and unaffected muscles, muscle pain, and joint pain. The median time from polio to the onset of these problems ranged from 30 to 40 years. Factors at onset of polio most strongly associated with developing these new health problems were: being hospitalized, being over 10 years old, being on a ventilator, and having paralytic involvement of all four limbs. The differential diagnoses of these new problems, implications for treatment and areas for future research are discussed.

Judgments of the potential benefits of rehabilitation research

A critical step in a project to develop a benefit-cost approach to evaluating proposed rehabilitation research has been to specify the potential benefits of such research in a reasonably systematic and comprehensive manner. The purposes of this study were: (1) to assess the contemporary relevance of 46 benefit factors yielded by a 1973 survey: (2) to acquire judgmental data to reduce these factors to fewer and more generic 2nd-order factors: (3) to compare 7 different rehabilitation role groups in terms of how the potential benefits of rehabilitation research are valued. "Hierarchical clustering" analyses of similarity judgments by 96 participants yielded 18 2nd-order benefit factors. A number of reliable differences were identified among the role groups regarding the value placed upon specific potential benefits of rehabilitation research.