Self-management intervention for patients following hospitalization for acute exacerbation of chronic obstructive pulmonary disease (AECOPD): A pilot randomized controlled trial

The purpose of this study was to evaluate the handoff guidance (HG) self-management intervention for multimorbid chronic obstructive pulmonary disease (COPD) patients following hospitalization for acute exacerbation of COPD (AECOPD) using HG self-management intervention compared to a control group on COPD self-management outcomes (self-care, self-efficacy, health engagement) and assess feasibility, acceptability, and healthcare utilization. A randomized pilot study used a 2-group with repeated measures design. Adults with COPD who had been hospitalized for AECOPD were recruited. After discharge, the HG self-management intervention employed health coaching delivered at: 1-3, 10-12, and 20-22 days after hospital discharge. Follow-up data collected was collected at 1-3, 10-12, 20-22, 30, 60, and 90 days after hospital discharge. A total of 29 subjects participated, with a mean age of 66 (+8.7) years old, the majority were females (n = 18). Intervention participants reported the acceptability of the HG self-management intervention. Participants in both groups continued to report COPD symptoms after discharge, which decreased over time, although not significantly different by group. The use of COPD maintenance, monitoring, and management behaviors was higher in the treatment group, although not significantly different.

Feasibility, acceptability, and usability of implementing a medical device-related pressure injury algorithm for critically ill patients using non-invasive ventilation

OBJECTIVES

Describe the feasibility, acceptability, and usability of implementing a nurse-led intervention to prevent medical device-related pressure injury in critical care patients using non-invasive ventilation during hospitalization.

STUDY DESIGN

A quality improvement project, using a descriptive single-arm study design with convenience sampling.

SETTING AND PARTICIPANTS

This study was conducted at a Midwestern medical center with 640 beds (two hospital campuses). After an educational session, the nurse-led algorithm for non-invasive ventilation medical device-related pressure injury prevention was implemented in two critical care nursing units (cardiac medical progressive care and neurotrauma intensive care unit). Nursing staff were full or part-time critical care nurses.

MAIN OUTCOME MEASURES

Feasibility, acceptability, and usability of the non-invasive ventilation medical device-related pressure injury algorithm were measured (bedside rounding and pre/post System Usability Scale).

RESULTS

Thirty-five nurses (52.2 %) completed a pre-educational survey; 8 (11.2 %) completed a post-survey. The total mean pre-survey score was 70.7 (SD ± 13.6) and the post-survey mean score was 71.3(SD ± 19.6). There was a statistically significant increase in the post-survey mean score {Χ2 (1, N = 43) = 43.5, p <.05}, however, the 0.06 increase was not clinically meaningful. Bedside rounding interviews (n = 22) indicated 82 % (n = 18) of the nurses used the algorithm. The SUS tool mean score was 83.3 (10.73) pre-implementation (n = 21); and 85.63 (8.26) post-implementation (n = 5), indicating clinical usability of the algorithm pre- and post-implementation.

CONCLUSION

The feasibility, acceptability, and usability of implementing a medical device-related pressure injury algorithm for critically ill patients using non-invasive ventilation were demonstrated during this study. More nursing research is needed to develop scalable interdisciplinary clinical algorithms to reduce medical device-related pressure injuries in patients using non-invasive ventilation.

IMPLICATIONS FOR CLINICAL PRACTICE

This study focused on the bedside usability of the algorithm in a clinical setting. Implementing this nursing-developed algorithm created an interdisciplinary framework in which nursing assessment may guide clinical care.

Nurse practitioner-led, virtually delivered, motivational enhancement and device support intervention to improve CPAP adherence: A feasibility randomized control trial

BACKGROUND

Evidence indicates continuous positive airway pressure (CPAP) therapy improves several important patient-centered outcomes. However, adherence to this safe and effective intervention remains poor.

OBJECTIVES

Assess nine feasibility outcomes of a nurse practitioner-led, virtually delivered motivational enhancement and device support (MENDS) intervention to improve CPAP adherence in adults with Obstructive Sleep Apnea (OSA). Secondary aims compared the changes in CPAP adherence to patient-reported outcomes, patient activation, and perceived self-efficacy.

METHODS

This two-group feasibility randomized controlled trial included 29 patients newly diagnosed with OSA and prescribed CPAP therapy. The study was conducted from July 2020 through December 2021 at a midwestern sleep/pulmonary clinic. Participants were randomized to the MENDS intervention group (n=14) (30-45 minute interactive tele-discussions on weeks 2, 4, 6, and 8) or to the usual care (n=15) group. Feasibility, patient-reported outcomes, and behavioral constructs were measured at baseline and 12 weeks. CPAP adherence was measured weekly.

RESULTS

Feasibility of the MENDS sessions was demonstrated (56 sessions offered, 52 completed remotely without technical difficulties) with minimal participant attrition and no missing CPAP data. Generalized linear mixed models showed no statistically significant time-by-group interactions on adherence or patient-reported outcomes. Higher adherence and lower CPAP apnea-hypopnea index (AHI) scores were associated with declines in pre- to post-changes in fatigue and sleep disturbance. Lower CPAP AHI scores were associated with pre- to post-decreases in PROMIS Anxiety scores (r=.532, p=.005).

CONCLUSION

The virtual MENDS intervention was feasible. Higher CPAP adherence and lower AHI levels led to positive improvements in fatigue, sleep disturbance, and anxiety.

Behavioral Weight Loss Interventions for Overweight and Obese Cardiac Rehabilitation Patients: A Systematic Review

The purpose of this systematic review was to identify evidence pertaining to the effectiveness of behavioral weight loss interventions for overweight and obese cardiac rehabilitation participants. A database search of PUBMED, CINAHL, PsycINFO, and PROSPERO yielded 10 eligible studies. Quantitative studies implementing behavioral weight loss interventions for overweight and obese adult cardiac rehabilitation participants were reviewed. Evidence supported the usefulness and effectiveness of behavioral weight loss interventions for overweight cardiac rehabilitation participants. With the limited number of studies and inclusion of quasi-experimental studies with comparative groups, it was not possible to determine the relative power of behavioral weight loss interventions across studies. In conclusion, behavioral weight loss interventions can be incorporated into cardiac rehabilitation or offered following cardiac rehabilitation to improve weight loss of overweight and obese cardiac rehabilitation participants. Findings reinforce national guidelines emphasizing the role of cardiac rehabilitation to address secondary cardiovascular disease risk factor modification, including integrating behavioral weight loss programs in cardiac rehabilitation, or referring overweight patients to weight management programs following completion of cardiac rehabilitation.

Experiences of Using a Self-management Mobile App Among Individuals With Heart Failure: Qualitative Study

BACKGROUND

Interventions that focus on the self-management of heart failure are vital to promoting health in patients with heart failure. Mobile health (mHealth) apps are becoming more integrated into practice to promote self-management strategies for chronic diseases, optimize care delivery, and reduce health disparities.

OBJECTIVE

The purpose of this study was to explore the experience of using a self-management mHealth intervention in individuals with heart failure to inform a future mHealth intervention study.

METHODS

This study used a qualitative descriptive design. Participants were enrolled in the intervention groups of a larger parent study using a mobile app related to self-management of heart failure. The purposive, convenient, criterion-based sample for this qualitative analysis comprised 10 patients who responded to phone calls and were willing to be interviewed. Inclusion criteria for the parent study were adults who were hospitalized at Nebraska Medical Center with a primary diagnosis and an episode of acute decompensated heart failure; discharged to home without services such as home health care; had access to a mobile phone; and were able to speak, hear, and understand English.

RESULTS

Study participants were middle-aged (mean age 55.8, SD 12 years; range 36-73 years). They had completed a mean of 13.5 (SD 2.2) years (range 11-17 years) of education. Of the 10 participants, 6 (60%) were male. Half of them (5/10, 50%) were New York Heart Association Classification Class III patients and the other half were Class IV patients. The intervention revealed four self-management themes, including (1) I didn't realize, and now I know; (2) It feels good to focus on my health; (3) I am the leader of my health care team; and (4) My health is improving.

CONCLUSIONS

Participants who used a self-management mHealth app intervention for heart failure reported an overall positive experience. Their statements were organized into four major themes. The education provided during the study increased self-awareness and promoted self-management of their heart failure. The mHealth app supported patient empowerment, resulting in better heart failure management and improved quality of life. Participants advocated for themselves by becoming the leader of their health, especially when communicating with their health care team. Finally, the mHealth app was used by the participants as a self-management tool to assist in symptom management and improve their overall health. Future research should study symptom evaluation, medication tracking, and possibly serve as a health provider communication platform to empower individuals to be leaders in their chronic disease management.

Outer-sphere effects on ligand-field excited-state dynamics: solvent dependence of high-spin to low-spin conversion in [Fe(bpy)3]2

In condensed phase chemistry, the solvent can have a significant impact on everything from yield to product distribution to mechanism. With regard to photo-induced processes, solvent effects have been well-documented for charge-transfer states wherein the redistribution of charge subsequent to light absorption couples intramolecular dynamics to the local environment of the chromophore. Ligand-field excited states are expected to be largely insensitive to such perturbations given that their electronic rearrangements are localized on the metal center and are therefore insulated from so-called outer-sphere effects by the ligands themselves. In contrast to this expectation, we document herein a nearly two-fold variation in the time constant associated with the 5T2 → 1A1 high-spin to low-spin relaxation process of tris(2,2'-bipyridine)iron(ii) ([Fe(bpy)3]2+) across a range of different solvents. Likely origins for this solvent dependence, including relevant solvent properties, ion pairing, and changes in solvation energy, were considered and assessed by studying [Fe(bpy)3]2+ and related derivatives via ultrafast time-resolved absorption spectroscopy and computational analyses. It was concluded that the effect is most likely associated with the volume change of the chromophore arising from the interconfigurational nature of the 5T2 → 1A1 relaxation process, resulting in changes to the solvent-solvent and/or solvent-solute interactions of the primary solvation shell sufficient to alter the overall reorganization energy of the system and influencing the kinetics of ground-state recovery.

Demographic, clinical, and biomarker predictors of apnea-hypopnea index from polysomnography in Midwestern sleep clinic patients

BACKGROUND

To examine if selected demographic (age, gender), clinical (diabetes, coronary artery disease, hyperlipidemia, myocardial infarction, stroke, lung disease, smoking history, alcohol intake), and biomarker [blood pressure (BP), heart rate, body mass index (BMI), neck circumference, Mallampati score] variables are predictors of apnea-hypopnea index (AHI) from polysomnography (PSG).

METHODS

This cross-sectional study recruited a sample of adults (N = 170) who were being evaluated for OSA. Participants completed self-reported demographic and clinical questionnaires, and then completed PSG (n = 142). Multi-collinearity was assessed. Confounding factors, correlations, and potential interactions were explored.

RESULTS

The final regression model was performed on 130 participants; 61 (46.9%) had an AHI ≥ 15. Systolic and diastolic BPs were highly correlated. Interactions were tested between gender and other variables (high cholesterol, BMI, neck circumference, systolic BP) and between systolic BP and other variables (high cholesterol, BMI, neck circumference, and lung disease). No interactions occurred between gender or systolic BP and other variables, meaning that the effects of the variables on AHI levels from PSG did not vary depending on gender or systolic BP. BMI, systolic BP, and absence of lung disease were predictors for AHI levels ≥ 15 from PSG.

CONCLUSIONS

BMI and systolic BP were significant predictors of OSA in this study. The absence of lung disease as a significant predictor was unique and may be due to the small number of participants who self-reported lung disease. To our knowledge, this is the first study to report this combination of variables to predict AHI levels ≥ 15 from PSG.

Comparisons of measures used to screen for obstructive sleep apnea in patients referred to a sleep clinic

STUDY OBJECTIVES

Obstructive Sleep Apnea (OSA) contributes to all-cause mortality. An American Academy of Sleep Medicine task force is focusing on improving detection and categorization of OSA symptoms and severity to promote screening, assessment, and diagnosis. The purpose of this study was to psychometrically compare measures used in OSA screening (Berlin, Epworth Sleepiness Scale (ESS), STOP Bang) and a portable sleep monitor (PSM) to apnea-hypopnea index (AHI) and levels from polysomnogram (PSG).

METHODS

An observational, cross-sectional design was used. Patients referred to a sleep specialist were enrolled at initial sleep evaluation. Participants completed measures used in OSA screening, then sent home for one night using PSM. PSGs were ordered by the physician and AHI results were obtained from the medical record.

RESULTS

Participants (N = 170) were enrolled in the study. Almost all participants completed the OSA measures, approximately half-completed PSM measurement, and the majority completed laboratory PSG. The STOP Bang had the highest levels of sensitivity; the ESS had the lowest. The ESS had the highest specificity and reliability levels; the STOP Bang had the lowest. The PSM measure had the highest positive predictive value (PPV) and the strongest psychometric properties of the screening measures.

CONCLUSIONS

The STOP Bang was the preferred self-report OSA screening measure because of high levels of sensitivity. The ESS was the least desirable measure. PSM measurement consistently predicted the presence of OSA but at the expense of low sensitivity at AHI levels ≥30. This expands the knowledge of validity testing of screening measures used for OSA.

Determining Zebrafish Epitope Reactivity to Commercially Available Antibodies

Antibodies raised against mammalian proteins may exhibit cross-reactivity with zebrafish proteins, making these antibodies useful for fish studies. However, zebrafish may express multiple paralogues of similar sequence and size, making them difficult to distinguish by traditional Western blot analysis. To identify the zebrafish proteins that are recognized by an antimammalian antibody, we developed a system to screen putative epitopes by cloning the sequences between the yeast SUMO protein and a C-terminal 6xHis tag. The recombinant fusion protein was expressed in Escherichia coli and analyzed by Western blot to conclusively identify epitopes that exhibit cross-reactivity with the antibodies of interest. This approach can be used to determine the species cross-reactivity and epitope specificity of a wide variety of peptide antigen-derived antibodies.

Fluorescent labeling of human albumin using the new aromatic dialdehyde labels and the study of innerfilter effect

The labels naphthalene-2,3-dicarboxaldehyde (NDA), 1-phenylnaphthalene-2,3-dialdehyde (ΦNDA), and anthracene-2,3-dialdehyde (ADA) have been used as fluorigenic reagents. They formed fluorescent derivatives with proteins. The derivatives formed are in fact isoindoles. The fluorescence decay of the labels-antibody was found to extend over a period of 4, 8, and 10 h for ΦNDA, ADA, and NDA-derivative, respectively. Protein formed is comparatively less stable as compared to simple amino acids. In relation to innerfilter effect, the addition of cytochrome C, myoglobin, and ATP as absorbers to label-human albumin fluorophores appeared to have quenched the fluorescence. In the case of using NDA as label, the fluorescence was quenched roughly 70%, 24%, and 58% for addition of cytochrome C, myoglobin, and ATP, respectively. The labels used were found to give rapid, reproducible, and reliable results.

Motility and chemotaxis in tissue penetration of oral epithelial cell layers by Treponema denticola

The ability to penetrate tissue is an important virulence factor for pathogenic spirochetes. Previous studies have recognized the role of motility in allowing pathogenic spirochetes to invade tissues and migrate to sites favorable for bacterial proliferation. However, the nature of the movements, whether they are random or controlled by chemotaxis systems, has yet to be established. In this study, we addressed the role of motility and chemotaxis in tissue penetration by the periodontal disease-associated oral spirochete Treponema denticola using an oral epithelial cell line-based experimental approach. Wild-type T. denticola ATCC 35405 was found to penetrate the tissue layers effectively, whereas a nonmotile mutant was unable to overcome the tissue barrier. Interestingly, the chemotaxis mutants also showed impaired tissue penetration. A cheA mutant that is motile but lacks the central kinase of the chemotaxis pathway showed only about 2 to 3% of the wild-type penetration rate. The two known chemoreceptors of T. denticola, DmcA and DmcB, also appear to be involved in the invasion process. The dmc mutants were actively motile but exhibited reduced tissue penetration of about 30 and 10% of the wild-type behavior, respectively. These data suggest that not only motility but also chemotaxis is involved in the tissue penetration by T. denticola.

Immunohistochemical analysis of Lyme disease in the skin of naive and infection-immune rabbits following challenge

In this study, skin histopathology from naive and infection-derived immune rabbits was compared following intradermal challenge using Borrelia burgdorferi B31 strain. The presence or absence of spirochetes in relationship to host cellular immune responses was determined from the time of intradermal inoculation to the time of erythema migrans (EM) development (approximately 7 days in naive rabbits) and through development of challenge immunity (approximately 5 months in naive rabbits). Skin biopsies were obtained and analyzed for the presence of spirochetes, B cells, T cells, polymorphonuclear cells (PMNs), and macrophages by immunohistochemical techniques. In infected naive animals, morphologically identifiable spirochetes were detected at 2 h and up to 3 weeks postinfection. At 12 and 24 h postinfection there was a marked PMN response that decreased by 36 to 48 h; by 72 h the PMNs were replaced by a few infiltrating macrophages. At the time of EM development and 14 days postinfection, the PMNs and macrophages were replaced by a lymphocytic infiltrate. There was a greater number of spirochetes at 14 days, a time when EM had resolved, than at 7 days postinfection. By 3 weeks postinfection there were few organisms and lymphocytes detectable. In contrast to infected naive rabbits, intact spirochetes were never visualized in skin biopsies from infection-immune rabbits; only spirochetal antigen was detected at 2, 12, and 24 h in the presence of a numerous PMN infiltrate. By 36 h postchallenge, spirochetal antigen could not be detected and the PMN response was replaced by a few infiltrating macrophages. By 72 h postchallenge, PMNs and macrophages were absent from the skin; B and T cells were never detected at any time point in skin from infection-immune rabbits. The destruction of spirochetes in immune animals in the presence of PMNs and in the absence of a lymphocytic infiltrate suggests that infection-derived immunity is antibody mediated.

Homologous and heterologous Borrelia burgdorferi challenge of infection-derived immune rabbits using host-adapted organisms

We have recently found that strain B31 infection-immune rabbits are completely protected against homologous challenge with large numbers (>10(6)) of host-adapted Borrelia burgdorferi (HAB) (E. S. Shang, C. I. Champion, X. Wu, J. T. Skare, D. B. Blanco, J. N. Miller, and M. A. Lovett, Infect. Immun. 68:4189-4199, 2000). In this study, we have extended these findings to determine whether B31 strain infection-immune rabbits are also protected against heterologous HAB challenge. Infection-immune rabbits challenged with large numbers (>10(6)) of homologous HAB strain B31 were completely protected from erythema migrans (EM) and skin and disseminated infection. In contrast, infection-immune rabbits challenged with heterologous HAB strains N40 and Sh-2-82 were completely susceptible to EM and skin and disseminated infection; challenge with strain 297 also resulted in EM and infection of the skin and viscera, but clearance of infection occurred 3 weeks postchallenge. These findings confirm that immunity elicited in rabbits by B31 strain infection confers complete protection against large-dose homologous HAB challenge but not against a heterologous strain.

Dual analyte flow injection fluorescence immunoassays using thiophilic gel reactors and synchronous scanning detection

Heterogeneous fluorescence immunoassays have been automated using flow injection manifolds incorporating thiophilic gel solid phase reactors to separate antibody-bound and unbound analyte molecules. Antibody elution is achieved by changes in ionic strength, thus allowing the use of pH sensitive fluorescent labels. This facilitates the development of dual analyte systems, in which two competitive immunoassays with separate labels are monitored in parallel. Detection of the fluorophores by high speed synchronous fluorescence scanning while the flow is briefly stopped utilises either one synchronous interval which detects both fluorophores, or two separate scans at different wavelength intervals, one for each fluorophore. Simultaneous analyses of serum albumin and transferrin exemplify these novel approaches. Spectroscopic interferences are very small, analyte recoveries are close to 100%, with a relative standard deviation of 5-6% and a sampling rate of 20 h-1.

The external validity of Asperger disorder: lack of evidence from the domain of neuropsychology

The present study compared individuals with high-functioning autism (HFA) and Asperger disorder (AD) in intellectual, motor, visuospatial, and executive function domains. Participants with AD demonstrated significantly higher Verbal and Full Scale IQ scores, significantly larger Verbal-Performance IQ discrepancies, and significantly better visual-perceptual skills than those with HFA. Once the superior intellectual abilities of the AD group were controlled (both statistically through analysis of covariance and by examining IQ-matched subgroups of HFA and AD participants), no significant group differences in motor, visuospatial, or executive functions were evident, save a marginally significant trend toward poorer fine motor performance in the AD group. This suggests that AD may simply be "high-IQ autism" and that separate names for the disorders may not be warranted. The relation of these findings to theories of autism and AD are discussed.

Comparison of protection in rabbits against host-adapted and cultivated Borrelia burgdorferi following infection-derived immunity or immunization with outer membrane vesicles or outer surface protein A

In this study, infection-derived immunity in the rabbit model of Lyme disease was compared to immunity following immunization with purified outer membrane vesicles (OMV) isolated from Borrelia burgdorferi and recombinant outer surface protein A (OspA). Immunization of rabbits with OMV isolated from virulent strain B31 and its avirulent derivative B313 (lacking OspA and DbpA) conferred highly significant protection against intradermal injection with 6 x 10(4) in vitro-cultivated virulent B. burgdorferi. This is the first demonstration of protective immunogenicity induced by OMV. While immunization with OspA and avirulent B31 OMV provided far less protection against this challenge, rabbits with infection-derived immunity were completely protected. Protection against host-adapted B. burgdorferi was assessed by implantation of skin biopsies taken from rabbit erythema migrans (a uniquely rich source of B. burgdorferi in vertebrate tissue) containing up to 10(8) spirochetes. While all of the OMV- and OspA-immunized rabbits were fully susceptible to skin and disseminated infection, rabbits with infection-derived immunity were completely protected. Analysis of the antibody responses to outer membrane proteins, including DbpA, OspA, and OspC, suggests that the remarkable protection exhibited by the infection-immune rabbits is due to antibodies directed at antigens unique to or markedly up-regulated in host-adapted B. burgdorferi.

Protection elicited by native outer membrane protein Oms66 (p66) against host-adapted Borrelia burgdorferi: conformational nature of bactericidal epitopes

Oms66 is a Borrelia burgdorferi outer membrane porin protein whose role in Lyme disease pathogenesis and immunity has not been well established. Oms66 was solubilized from whole-cell lysates of strain B313 (which is derived from B31 but lacks OspA, -B, -C, and -D) and purified to homogeneity by fast-protein liquid chromatography. Purified native Oms66 (nOms66), which retained the ability to form large channels in a planar lipid bilayer model membrane system, and denatured Oms66 (hOms66) were used to immunize New Zealand White rabbits. The resulting Oms66 antisera were tested in a complement-dependent borreliacidal assay in parallel with basal serum and with serum from rabbits immune to reinfection with B. burgdorferi (IRS). IRS showed high-titer complement-dependent killing of both strains B31 and B313. Sera from animals immunized with nOms66 showed high-titer complement-dependent killing activity against strain B313 but exhibited no killing of B31. By comparison, serum generated from immunizations with hOms66 showed no killing activity against either strain. Following adsorption of antiserum to nOms66 with recombinant Oms66 (rOms66), the serum antibodies no longer bound to rOms66 or to nOms66 that had been denatured with 8 M urea. However, the antibodies still bound to nOms66 and killing activity against B313 was retained, thus suggesting that native, conformational epitopes are targets of this bactericidal activity. Six C3H HeJ mice were immunized with nOms66 and were challenged using "host-adapted" B. burgdorferi B31 by skin implantation of infected mouse ear tissue. Four of the six mice were protected against both localized and disseminated infection. These findings indicate that native Oms66 can elicit potent bactericidal activity and significant protective immunity against host-adapted organisms.

Renaturation of recombinant Treponema pallidum rare outer membrane protein 1 into a trimeric, hydrophobic, and porin-active conformation

We have previously observed that while native Treponema pallidum rare outer membrane protein 1 (Tromp1) is hydrophobic and has porin activity, recombinant forms of Tromp1 do not possess these properties. In this study we show that these properties are determined by conformation and can be replicated by proper renaturation of recombinant Tromp1. Native Tromp1, but not the 47-kDa lipoprotein, extracted from whole organisms by using Triton X-114, was found to lose hydrophobicity after treatment in 8 M urea, indicating that Tromp1's hydrophobicity is conformation dependent. Native Tromp1 was purified from 0.1% Triton X-100 extracts of whole organisms by fast-performance liquid chromatography (FPLC) and shown to have porin activity in planar lipid bilayers. Cross-linking studies of purified native Tromp1 with an 11 A cross-linking agent showed oligomeric forms consistent with dimers and trimers. For renaturation studies of recombinant Tromp1 (rTromp1), a 31,109-Da signal-less construct was expressed in Escherichia coli and purified by FPLC. FPLC-purified rTromp1 was denatured in 8 M urea and then renatured in the presence of 0.5% Zwittergent 3,14 during dialysis to remove the urea. Renatured rTromp1 was passed through a Sephacryl S-300 gel exclusion column previously calibrated with known molecular weight standards. While all nonrenatured rTromp1 eluted from the column at approximately the position of the carbonic anhydrase protein standard (29 kDa), all renatured rTromp1 eluted at the position of the phosphorylase b protein standard (97 kDa), suggesting a trimeric conformation. Trimerization was confirmed by using an 11 A cross-linking agent which showed both dimers and trimers similar to that of native Tromp1. Triton X-114 phase separations showed that all of renatured rTromp1, but none of nonrenatured rTromp1, phase separated exclusively into the hydrophobic detergent phase, similar to native Tromp1. Circular dichroism of nonrenatured and renatured rTromp1 showed a marked loss in alpha-helical secondary structure of renatured rTromp1 compared to the nonrenatured form. Finally, renatured rTromp1, but not the nonrenatured form, showed porin activity in planar liquid bilayers. These results demonstrate that proper folding of rTromp1 results in a trimeric, hydrophobic, and porin-active conformation similar to that of the native protein.

Sensitive and specific serodiagnosis of Lyme disease by enzyme-linked immunosorbent assay with a peptide based on an immunodominant conserved region of Borrelia burgdorferi vlsE

VlsE, the variable surface antigen of Borrelia burgdorferi, contains an immunodominant conserved region named IR(6). In the present study, the diagnostic performance of a peptide enzyme-linked immunosorbent assay (ELISA) based on a 26-mer synthetic peptide (C(6)) with the IR(6) sequence was explored. Sensitivity was assessed with serum samples (n = 210) collected from patients with clinically defined Lyme disease at the acute (early localized or early disseminated disease), convalescent, or late disease phase. The sensitivities for acute-, convalescent-, and late-phase specimens were 74% (29 of 39), 85 to 90% (34 of 40 to 35 of 39), and 100% (59 of 59), respectively. Serum specimens from early neuroborreliosis patients were 95% positive (19 of 20), and those from an additional group of patients with posttreatment Lyme disease syndrome yielded a sensitivity of 62% (8 of 13). To assess the specificity of the peptide ELISA, 77 serum samples from patients with other spirochetal or chronic infections, autoimmune diseases, or neurologic diseases and 99 serum specimens from hospitalized patients in an area where Lyme disease is not endemic were examined. Only two potential false positives from the hospitalized patients were found, and the overall specificity was 99% (174 of 176). Precision, which was assessed with a panel of positive and negative serum specimens arranged in blinded duplicates, was 100%. Four serum samples with very high anti-OspA antibody titers obtained from four monkeys given the OspA vaccine did not react with the C(6) peptide. This simple, sensitive, specific, and precise ELISA may contribute to alleviate some of the remaining problems in Lyme disease serodiagnosis. Because of its synthetic peptide base, it will be inexpensive to manufacture. It also will be applicable to serum specimens from OspA-vaccinated subjects.

Autism and autistic behavior in Joubert syndrome

To determine whether individuals with Joubert syndrome exhibit features of autism as defined by the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV), we examined 11 children with Joubert syndrome using the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule-Generic. Three children met DSM-IV criteria for autistic disorder and one for pervasive developmental disorder not otherwise specified. The other seven all demonstrated at least one DSM-IV symptom of autism, but did not meet criteria for a pervasive developmental disorder. Both total number of DSM-IV symptoms and number of social symptoms distinguished the autism and nonautism subgroups. In contrast, the two subgroups displayed similar levels of communication impairments and repetitive or stereotyped behavior. The key to diagnosing autism in Joubert syndrome is to focus on social behaviors, particularly milestones typically achieved very early in life (eg, attending to human voices, showing objects of interest, enjoyment of social interactions). Implications for the role of the cerebellum in nonmotor behavior and for clinical management of Joubert syndrome also are discussed.

Cloning and molecular characterization of plasmid-encoded antigens of Borrelia burgdorferi

Thirteen independent clones that encode Borrelia burgdorferi antigens utilizing antiserum from infection-immune rabbits were identified. The serum was adsorbed against noninfectious B. burgdorferi B31 to enrich for antibodies directed against either infection-associated antigens of B. burgdorferi B31 or proteins preferentially expressed during mammalian infection. The adsorption efficiency of the immune rabbit serum (IRS) was assessed by Western immunoblot analysis with protein lysates derived from infectious and noninfectious B. burgdorferi B31. The adsorbed IRS was used to screen a B. burgdorferi expression library to identify immunoreactive phage clones. Clones were then expressed in Escherichia coli and subsequently analyzed by Western blotting to determine the molecular mass of the recombinant B. burgdorferi antigens. Southern blot analysis of the 13 clones indicated that 10 contained sequences unique to infectious B. burgdorferi. Nucleotide sequence analysis indicated that the 13 clones were composed of 9 distinct genetic loci and that all of the genes identified were plasmid encoded. Five of the clones carried B. burgdorferi genes previously identified, including those encoding decorin binding proteins A and B (dbpAB), a rev homologue present on the 9-kb circular plasmid (cp9), a rev homologue from the 32-kb circular plasmid (cp32-6), erpM, and erpX. Additionally, four previously uncharacterized loci with no known homologues were identified. One of these unique clones encoded a 451-amino-acid lipoprotein with 21 consecutive, invariant 9-amino-acid repeats near the amino terminus that we have designated VraA (for "virulent strain-associated repetitive antigen A"). Since all the antigens identified are recognized by serum from infection immune rabbits, these antigens represent potential vaccine candidates and, based on the identification of dbpAB in this screen, may also be involved in pathogenic processes operative in Lyme borreliosis.

Immunization with Treponema pallidum outer membrane vesicles induces high-titer complement-dependent treponemicidal activity and aggregation of T. pallidum rare outer membrane proteins (TROMPs)

The purpose of this study was to determine whether immunization with purified outer membrane vesicles (OMV) from Treponema pallidum (T.p. ) could elicit Abs capable of killing this organism. It is well established that the immunization of rabbits or mice with killed T.p. or with recombinant T.p. Ags has failed to generate serum killing activity comparable with that of infection-derived immunity. Because of the small amount of T.p. OMV obtainable, a single mouse was immunized with purified OMV. The mouse anti-OMV serum and infection-derived immune rabbit serum (IRS) were compared by reactivities on two-dimensional T.p. immunoblots and by the T.p. immobilization test, a complement-dependent killing assay. Whereas IRS detected >40 Ags, the anti-OMV serum identified only 6 Ags corresponding to proteins identified previously in the outer membrane. T.p. immobilization testing showed that IRS had a 100% killing titer of 1:44 and a 50% killing titer of 1:662. By comparison, the mouse anti-OMV serum had a significantly greater 100% killing titer of 1:1,408 and a 50% killing titer of 1:16,896. Absorption of the anti-OMV serum to remove Ab against outer membrane-associated lipoproteins did not change the 100% killing titer. Freeze-fracture analysis of T.p. incubated in IRS or anti-OMV serum showed that T.p. rare membrane-spanning outer membrane proteins were aggregated. This is the first demonstration of high-titer killing Abs resulting from immunization with defined T.p. molecules; our study indicates that the targets for these Abs are T. p. rare outer membrane proteins.

Demonstration by mass spectrometry that purified native Treponema pallidum rare outer membrane protein 1 (Tromp1) has a cleaved signal peptide

Purified native Tromp1 was subjected to mass spectrometric analysis in order to determine conclusively whether this protein possesses a cleaved or uncleaved signal peptide. The molecular masses of Tromp1, three Treponema pallidum lipoproteins, and a bovine serum albumin (BSA) control were determined by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. The molecular masses of all of the T. pallidum lipoproteins and BSA were within 0.7% of their respective calculated masses. The molecular mass of Tromp1 was 31,510 Da, which is consistent with a signal-less form of Tromp1, given a calculated mass of unprocessed Tromp1 of 33, 571 Da, a difference of 2,061 Da (a 6.5% difference). Purified native Tromp1 was also subjected to MALDI-TOF analysis in comparison to recombinant Tromp1 following cyanogen bromide cleavage, which further confirmed the identity of Tromp1 and showed that native Tromp1 was not degraded at the carboxy terminus. These studies confirm that Tromp1 is processed and does not contain an uncleaved signal peptide as previously reported.

Correlation of immunity in experimental syphilis with serum-mediated aggregation of Treponema pallidum rare outer membrane proteins

We have previously shown by freeze-fracture electron microscopy that serum from infection-immune syphilitic rabbits aggregates the low-density membrane-spanning Treponema pallidum rare outer membrane proteins (TROMPs). The purpose of this study was to determine if a relationship could be demonstrated between acquired immunity in experimental rabbit syphilis, serum complement-dependent treponemicidal antibody, and antibody directed against TROMPs as measured by the aggregation of TROMP particles. Three groups of T. pallidum-infected rabbits were treated curatively with penicillin at 9 days, 30 days, and 6 months postinfection to generate various degrees of immunity to challenge reinfection. Sera from rabbits completely susceptible to localized and disseminated reinfection possessed a low titer of treponemicidal antibody (</=1:1 in killing >/=50% of a treponemal suspension) and showed a correspondingly low level of TROMP aggregation (16.5% of the total number of outer membrane particles counted) similar to normal serum controls (13. 4%); the number of particles within these aggregates never exceeded three. Sera from partially immune rabbits, which were susceptible to local reinfection but had no evidence of dissemination, showed an increase in the titer of treponemicidal antibody (1:16) compared to the completely susceptible group (</=1:1). Although no significant increase was observed in the total number of TROMP particles aggregated (18.9%) compared to the number in controls (13.4%), approximately 15% of these aggregates did exhibit a significant increase in the number of particles per aggregate (4 to 5 particles) compared to controls (</=3 particles), indicating a measurable increase in anti-TROMP antibody. Finally, sera from rabbits completely immune to both local and disseminated reinfection possessed both high titers of treponemicidal antibody (1:128) and significant aggregation of TROMP (88.6%); approximately 50% of these aggregates contained four to six particles. The results indicate that complete immunity in experimental rabbit syphilis correlates with antibody that kills T. pallidum and aggregates TROMPs, suggesting that TROMPs are molecules which contribute to the development of acquired immunity.

Isolation and characterization of the outer membrane of Borrelia hermsii

The outer membrane of Borrelia hermsii has been shown by freeze-fracture analysis to contain a low density of membrane-spanning outer membrane proteins which have not yet been isolated or identified. In this study, we report the purification of outer membrane vesicles (OMV) from B. hermsii HS-1 and the subsequent identification of their constituent outer membrane proteins. The B. hermsii outer membranes were released by vigorous vortexing of whole organisms in low-pH, hypotonic citrate buffer and isolated by isopycnic sucrose gradient centrifugation. The isolated OMV exhibited porin activities ranging from 0.2 to 7.2 nS, consistent with their outer membrane origin. Purified OMV were shown to be relatively free of inner membrane contamination by the absence of measurable beta-NADH oxidase activity and the absence of protoplasmic cylinder-associated proteins observed by Coomassie blue staining. Approximately 60 protein spots (some of which are putative isoelectric isomers) with 25 distinct molecular weights were identified as constituents of the OMV enrichment. The majority of these proteins were also shown to be antigenic with sera from B. hermsii-infected mice. Seven of these antigenic proteins were labeled with [3H]palmitate, including the surface-exposed glycerophosphodiester phosphodiesterase, the variable major proteins 7 and 33, and proteins of 15, 17, 38, 42, and 67 kDa, indicating that they are lipoprotein constituents of the outer membrane. In addition, immunoblot analysis of the OMV probed with antiserum to the Borrelia garinii surface-exposed p66/Oms66 porin protein demonstrated the presence of a p66 (Oms66) outer membrane homolog. Treatment of intact B. hermsii with proteinase K resulted in the partial proteolysis of the Oms66/p66 homolog, indicating that it is surface exposed. This identification and characterization of the OMV proteins should aid in further studies of pathogenesis and immunity of tick-borne relapsing fever.

The Oms66 (p66) protein is a Borrelia burgdorferi porin

In this study we report the purification and characterization of a 66-kDa protein, designated Oms66, for outer membrane-spanning 66-kDa protein, that functions as a porin in the outer membrane (OM) of Borrelia burgdorferi. Oms66 was purified by fast-performance liquid chromatography and exhibited an average single-channel conductance of 9.62 +/- 0.37 nS in 1 M KCl, as evidenced by 581 individual insertional events in planar lipid bilayers. Electrophysiological characterization indicated that Oms66 was virtually nonselective between cations and anions and exhibited voltage-dependent closure with multiple substates. The amino acid sequence of tryptic peptides derived from purified Oms66 was identical to the deduced amino acid sequence of p66, a previously described surface-exposed protein of B. burgdorferi. Purified Oms66 was recognized by antiserum specific for p66 and serum from rabbits immune to challenge with virulent B. burgdorferi, indicating that p66 and Oms66 were identical proteins and that Oms66/p66 is an immunogenic protein in infected rabbits. In a methodology that reduces liposomal trapping and nonspecific interactions, native Oms66 was incorporated into liposomes, confirming that Oms66 is an outer membrane-spanning protein. Proteoliposomes containing Oms66 exhibited porin activity nearly identical to that of native, purified Oms66, indicating that reconstituted Oms66 retained native conformation. The use of proteoliposomes reconstituted with Oms66 and other Oms proteins provides an experimental system for determinating the relationship between conformation, protection, and biological function of these molecules.

Acquired resistance to Borrelia burgdorferi infection in the rabbit. Comparison between outer surface protein A vaccine- and infection-derived immunity

Intradermal inoculation of the rabbit with Borrelia burgdorferi, sensu lato, results in the consistent development of erythema migrans (EM), dermal infection, and visceral dissemination of the spirochete. Within 5 mo, EM as well as dermal and visceral infection are cleared and the animals exhibit immunity to reinfection. This study compares infection-derived immunity with acquired resistance resulting from the administration of a lipidated recombinant outer surface protein A (OspA) vaccine presently undergoing human trial. 4 of 11 OspA vaccinated rabbits, challenged intradermally at each of 10 sites with 10(5) low passage B. burgdorferi, developed EM as well as dermal and disseminated infection. After identical challenge, 2 of the 11 infection-immune rabbits developed a dermal infection, but not EM or disseminated infection. Further, ELISA anti-OspA titers did not correlate with the status of immunity for either OspA vaccinated or infection-immune rabbits. Prechallenge ELISA anti-OspA titers were relatively low in the infection-immune group. This study demonstrates that a state of partial immunity to experimental Lyme disease may result that could potentially mask infection. Further, our data strongly suggest that immunogen(s) other than OspA is/are responsible for stimulating acquired resistance in the infection-immune rabbit.

Sequence analysis and characterization of a 40-kilodalton Borrelia hermsii glycerophosphodiester phosphodiesterase homolog

We report the purification, molecular cloning, and characterization of a 40-kDa glycerophosphodiester phosphodiesterase homolog from Borrelia hermsii. The 40-kDa protein was solubilized from whole organisms with 0.1% Triton X-100, phase partitioned into the Triton X-114 detergent phase, and purified by fast-performance liquid chromatography (FPLC). The gene encoding the 40-kDa protein was cloned from a B. hermsii chromosomal DNA lambda EXlox expression library and identified by using affinity antibodies generated against the purified native protein. The deduced amino acid sequence included a 20-amino-acid signal peptide encoding a putative leader peptidase II cleavage site, indicating that the 40-kDa protein was a lipoprotein. Based on significant homology (31 to 52% identity) of the 40-kDa protein to glycerophosphodiester phosphodiesterases of Escherichia coli (GlpQ), Bacillus subtilis (GlpQ), and Haemophilus influenzae (Hpd; protein D), we have designated this B. hermsii 40-kDa lipoprotein a glycerophosphodiester phosphodiesterase (Gpd) homolog, the first B. hermsii lipoprotein to have a putative functional assignment. A nonlipidated form of the Gpd homolog was overproduced as a fusion protein in E. coli BL21(DE3)(pLysE) and was used to immunize rabbits to generate specific antiserum. Immunoblot analysis with anti-Gpd serum recognized recombinant H. influenzae protein D, and conversely, antiserum to H. influenzae protein D recognized recombinant B. hermsii Gpd (rGpd), indicating antigenic conservation between these proteins. Antiserum to rGpd also identified native Gpd as a constituent of purified outer membrane vesicles prepared from B. hermsii. Screening of other pathogenic spirochetes with anti-rGpd serum revealed the presence of antigenically related proteins in Borrelia burgdorferi, Treponema pallidum, and Leptospira kirschneri. Further sequence analysis both upstream and downstream of the Gpd homolog showed additional homologs of glycerol metabolism, including a glycerol-3-phosphate transporter (GlpT), a glycerol-3-phosphate dehydrogenase (GlpD), and a thioredoxin reductase (TrxB).

Sequence analysis and recombinant expression of a 28-kilodalton Treponema pallidum subsp. pallidum rare outer membrane protein (Tromp2)

In this study, we report the cloning, sequencing, and expression of the gene encoding a 28-kDa Treponema pallidum subsp. pallidum rare outer membrane protein (TROMP), designated Tromp2. The tromp2 gene encodes a precursor protein of 242 amino acids including a putative signal peptide of 24 amino acids ending in a type I signal peptidase cleavage site of Leu-Ala-Ala. The mature protein of 218 amino acids has a calculated molecular weight of 24,759 and a calculated pI of 7.3. The predicted secondary structure of Tromp2 shows nine transmembrane segments of amphipathic beta-sheets typical of outer membrane proteins. Recombinant Tromp2 (rTromp2) was expressed with its native signal peptide, using a tightly regulated T7 RNA polymerase expression vector. Under high-level expression conditions, rTromp2 fractionated exclusively with the Escherichia coli outer membrane. Antiserum raised against rTromp2 was generated and used to identify native Tromp2 in cellular fractionations. Following Triton X-114 extraction and phase separation of T. pallidum, the 28-kDa Tromp2 protein was detected prominently in the detergent phase. Alkali and high-salt treatment of purified outer membrane from T. pallidum, conditions which remove peripherally associated membrane proteins, demonstrated that Tromp2 is an integral membrane protein. Whole-mount immunoelectron microscopy of E. coli cells expressing rTromp2 showed specific surface antibody binding. These findings demonstrate that Tromp2 is a membrane-spanning outer membrane protein, the second such protein to be identified for T. pallidum.

Did Asperger's cases have Asperger disorder? A research note

With publication of the fourth edition of the Diagnostic and statistical manual of mental disorders (DSM-IV), standardized criteria for Asperger Disorder, a putative subtype of Pervasive Developmental Disorder, are now available. This paper examines the four cases Asperger originally presented in his seminal paper (1991/1994), using DSM-IV criteria to determine whether a diagnosis of Autistic or Asperger Disorder is most appropriate. We found that all four cases met DSM-IV criteria for Autistic Disorder, rather than Asperger Disorder. This suggests that the syndrome Asperger originally described may not be captured by present diagnostic criteria. Implications for future research are discussed.

Surface antigens of the syphilis spirochete and their potential as virulence determinants

A unique physical feature of Treponema pallidum, the venereally transmitted agent of human syphilis, is that its outer membrane contains 100-fold less membrane-spanning protein than the outer membranes of typical gram-negative bacteria, a property that has been related to the chronicity of syphilitic infection. These membrane-spanning T. pallidum rare outer membrane proteins, termed TROMPs, represent potential surface-exposed virulence determinants and targets of host immunity. Only recently has the outer membrane of T. pallidum been isolated and its constituent proteins identified. Five proteins of molecular mass 17-, 28-, 31-, 45-, and 65-kDa were outer membrane associated. The 17- and 45-kDa proteins, which are also present in greater amounts with the T. pallidum inner membrane protoplasmic cylinder complex, had been previously characterized lipoproteins and are, therefore, not membrane-spanning but rather membrane-anchored by their lipid moiety. In contrast, the 28-, 31-, and 65-kDa proteins are exclusively associated with the outer membrane. Both the purified native and an Escherichia coli recombinant outer membrane form of the 31-kDa protein, designated Tromp1, exhibit porin activity, thereby confirming the membrane-spanning outer membrane topology of Tromp1. The 28-kDa protein, designated Tromp2, has sequence characteristics in common with membrane-spanning outer membrane proteins and has also been recombinantly expressed in E. coli, where it targets exclusively to the E. coli outer membrane. The 65-kDa protein, designated Tromp3, is present in the least amount relative to Tromps1 and 2. Tromps 1, 2, and 3 were antigenic when tested with serum from infection and immune syphilitic rabbits and humans. These newly identified TROMPs provide a molecular foundation for the future study of syphilis pathogenesis and immunity.

Recombinant Treponema pallidum rare outer membrane protein 1 (Tromp1) expressed in Escherichia coli has porin activity and surface antigenic exposure

We recently reported the cloning and sequencing of the gene encoding a 31-kDa Treponema pallidum subsp. pallidum rare outer membrane porin protein, designated Tromp1 (D. R. Blanco, C. I. Champion, M. M. Exner, H. Erdjument-Bromage, R. E. W. Hancock, P. Tempst, J. N. Miller, and M. A. Lovett, J. Bacteriol. 177:3556-3562, 1995). Here, we report the stable expression of recombinant Tromp1 (rTromp1) in Escherichia coli. rTromp1 expressed without its signal peptide and containing a 22-residue N-terminal fusion resulted in high-level accumulation of a nonexported soluble protein that was purified to homogeneity by fast protein liquid chromatography (FPLC). Specific antiserum generated to the FPLC-purified rTromp1 fusion identified on immunoblots of T. pallidum the native 31-kDa Tromp1 protein and two higher-molecular-mass oligomeric forms of Tromp1 at 55 and 80 kDa. rTromp1 was also expressed with its native signal peptide by using an inducible T7 promoter. Under these conditions, rTromp1 fractionated predominantly with the E. coli soluble and outer membrane fractions, but not with the inner membrane fraction. rTromp1 isolated from the E. coli outer membrane and reconstituted into planar lipid bilayers showed porin activity based on average single-channel conductances of 0.4 and 0.8 nS in 1 M KCl. Whole-mount immunoelectron microscopy using infection-derived immune serum against T. pallidum indicated that rTromp1 was surface exposed when expressed in E. coli. These findings demonstrate that rTromp1 can be targeted to the E. coli outer membrane, where it has both porin activity and surface antigenic exposure.

Porin activity of the native and recombinant outer membrane protein Oms28 of Borrelia burgdorferi

The outer membrane-spanning (Oms) proteins of Borrelia burgdorferi have been visualized by freeze-fracture analysis but, until recently, not further characterized. We developed a method for the isolation of B. burgdorferi outer membrane vesicles and described porin activities with single-channel conductances of 0.6 and 12.6 nS in 1 M KCI. By using both nondenaturing isoelectric focusing gel electrophoresis and fast-performance liquid chromatography separation after detergent solubilization, we found that the 0.6-nS porin activity resided in a 28-kDa protein, designated Oms28. The oms28 gene was cloned, and its nucleotide sequence was determined. The deduced amino acid sequence of Oms28 predicted a 257-amino-acid precursor protein with a putative 24-amino-acid leader peptidase I signal sequence. Processed Oms28 yielded a mature protein with a predicted molecular mass of 25,363 Da. When overproduced in Escherichia coli, the Oms28 porin fractionated in part to the outer membrane. Sodium dodecyl sulfate-polyacrylamide gel-purified recombinant Oms28 from E. coli retained functional activity as demonstrated by an average single-channel conductance of 1.1 nS in the planar lipid bilayer assay. These findings confirmed that Oms28 is a B. burgdorferi porin, the first to be described. As such, it is potential relevance to the pathogenesis of Lyme borreliosis and to the physiology of the spirochete.

An exploration of right-hemisphere contributions to the pragmatic impairments of autism

This study examined the potential contribution of the right hemisphere to the communicative impairments of autism. Pragmatic language measures sensitive to right-hemisphere damage were administered to nonretarded adults with autism and to controls matched on age and intellectual ability. The experimental battery included measures of humor, inference, and indirect request comprehension. Autistic subjects performed significantly less well than controls on all measures, replicating results of an earlier investigation by Rumsey and Hanahan (Journal of Clinical and Experimental Neuropsychology, 12, 81, 1990). The performance of the autistic group on the three tasks was also similar to that of right-hemisphere stroke patients reported previously (Molloy, Brownell, & Gardner, in Y. Joanette and H. M. Brownell (Eds.), Discourse ability and brain damage: Theoretical and empirical perspectives, New York: Springer-Verlag, 1990,pp. 113-130). Generalizability of these results and implications for the neuropathology of autism are discussed.

Virulent strain associated outer membrane proteins of Borrelia burgdorferi

We have isolated and purified outer membrane vesicles (OMV) from Borrelia burgdorferi strain B31 based on methods developed for isolation of Treponema pallidum OMV. Purified OMV exhibited distinct porin activities with conductances of 0.6 and 12.6 nano-Siemen and had no detectable beta-NADH oxidase activity indicating their outer membrane origin and their lack of inner membrane contamination, respectively. Hydrophobic proteins were identified by phase partitioning with Triton X-114. Most of these hydrophobic membrane proteins were not acylated, suggesting that they are outer membrane-spanning proteins. Identification of palmitate-labeled lipoproteins revealed that several were enriched in the OMV, several were enriched in the protoplasmic cylinder inner membrane fraction, and others were found exclusively associated with the inner membrane. The protein composition of OMV changed significantly with successive in vitro cultivation of strain B31. Using antiserum with specificity for virulent strain B31, we identified OMV antigens on the surface of the spirochete and identified proteins whose presence in OMV could be correlated with virulence and protective immunity in the rabbit Lyme disease model. These virulent strain associated outer membrane-spanning proteins may provide new insight into the pathogenesis of Lyme disease.

Neurologic function and neuromuscular blocking agents in critical care

Neuromuscular blocking agent (NMBA) use in critical care units is generally reserved for life threatening situations. The goal of any life-support effort, including efficient mechanical ventilation, maintenance of hemodynamic stability, and NMBA use, is to optimize cerebral preservation. Yet, although all other organ systems are aggressively monitored, very little is done to assess neurologic stability during NMBA therapy. This article addresses the neurologic issues associated with NMBA use: identification of those patients at risk for a neurologic event; rationale for monitoring cerebral changes during paralytic therapy; and potential means of assessing and intervening before, during, and after chemical paralysis.

Teaching theory of mind: a new approach to social skills training for individuals with autism

This study examined the effectiveness of a social skills training program for normal-IQ adolescents with autism. Five boys participated in the 4 1/2-month treatment condition; four boys matched on age, IQ, and severity of autism constituted the no-treatment control group. In addition to teaching specific interactional and conversational skills, the training program provided explicit and systematic instruction in the underlying social-cognitive principles necessary to infer the mental states of others (i.e., theory of mind). Pre- and post-intervention assessment demonstrated meaningful change in the treatment group's performance on several false belief tasks, but no improvement in the control sample. No changes, however, were demonstrated on general parent and teacher ratings of social competence for either group.

Comprehensive review: neuromuscular blocking agents in critical care

Administration of neuromuscular blocking agents (NMBAs) in critical care units has become tremendously controversial. The increased use of these agents without a defined indication or research base has resulted in dangerous and costly complications and serious concerns. Areas of controversy include mounting adverse effects (especially prolonged paralysis and weakness from long-term overdosing), an inconsistent and deficient knowledge base among all levels of health care professionals, inadequate concurrent sedation and analgesia, and a lack of effective monitoring to ensure the lowest possible doses. There is a great need for research to define the practice and protocols that would optimize safe and efficacious use. Pharmacologic paralysis should be restricted to a very specific patient population after careful evaluation, and therapy should be discontinued at the earliest possible time. Chemical paralysis can be a safe and effective therapy for a select few patients when judicious care, multidisciplinary efforts, and prevention of adverse effects minimize the complications, growing costs, and unintended suffering.

Rabbit model of Lyme borreliosis: erythema migrans, infection-derived immunity, and identification of Borrelia burgdorferi proteins associated with virulence and protective immunity

Erythema migrans (EM), persistent skin infection, and visceral dissemination can be induced reproducibly in the adult male New Zealand White rabbit by intradermal injection of as few as 10(3) Borrelia burgdorferi. EM was found to persist for 7 +/- 3 d. Skin culture positivity (infection) cleared within a mean of 6.7 +/- 1.4 wk after infection and similarly visceral infection was not demonstrated after 8 wk; infection-derived immunity to intradermal challenge was evident 5 mo after initial infection. The extent of the protection against EM and dermal infection induced by untreated infection was directly related to the extent of prior in vitro passage of the B31 strain. Initial infection with as few as 4 x 10(3) B31 passage 4 induced complete protection against EM and skin infection upon subsequent challenge with 4 x 10(7) B31, passage 4. Initial infection with B31 passage 27 led to partial protection against EM along with complete protection against skin infection. Initial infection with passage 47 led to partial protection against EM, but conferred no protection against skin infection. Using serum from rabbits fully immune to reinfection, we defined a set of B. burgdorferi proteins present in virulent B31, but absent in the avirulent American Type Culture Collection B31 strain, termed "va" for virulent strain associated. The va proteins of B31 passages 1, 27, and 47 differed strikingly, thus raising the possibility that these changes may relate in a causal way to the differences in induction of protective immunity observed.

An investigation of the use of nile red as a long-wavelength fluorescent probe for the study of alpha 1-acid glycoprotein-drug interactions

Spectrofluorimetry in the long-wavelength region of the electromagnetic spectrum (600-1000 nm) is a fairly recent development in photoluminescence spectroscopy, which has numerous advantages over measurements in the more conventional ultraviolet and visible spectral region. 9-Diethylamino-5H-benzophenoxazine-5-one (Nile Red) is an unchanged, hydrophobic molecule, and long-wavelength fluorescence of which is strongly influenced by the polarity of its environment. When Nile Red was added to solutions of alpha 1-acid glycoprotein (Orosomucoid. OMD), it showed an enhancement in fluorescence intensity and a shift to blue in emission wavelength, suggesting it was binding hydrophobically to a non-polar site on the protein. The association constant (12,261,000 +/- 900,000 M-1) and number of binding sites (0.746 +/- 0.044) were calculated for the probe. Upon addition of both acidic and basic drugs, the Nile Red fluorescence reverted to its unbound form, indicating that OMD probably has one high-affinity, wide and flexible binding area for such drugs. Possible enantiomeric selectivity was shown with ephedrine, and the association constant determined for a racemic mixture of propranolol was found to be comparable to other values obtained with alternative, more conventional techniques.

Porin activity and sequence analysis of a 31-kilodalton Treponema pallidum subsp. pallidum rare outer membrane protein (Tromp1)

We have recently reported the isolation and purification of the Treponema pallidum outer membrane and the identification of its rare protein constituents, including a 31-kDa protein markedly enriched in the outer membrane preparation (D.R. Blanco, K. Reimann, J. Skare, C.I. Champion, D. Foley, M. M. Exner, R. E. W. Hancock, J. N. Miller, and M. A. Lovett, J. Bacteriol. 176:6088-6099, 1994). In this study, we report the cloning, sequencing, and expression of the structural gene which encodes the 31-kDa outer membrane protein, designated Tromp1. The deduced amino acid sequence from the tromp1 gene sequence encodes a 318-amino-acid polypeptide with a putative 40-amino-acid signal peptide. Processing of Tromp1 results in a mature protein with a predicted molecular mass of 30,415 Da and a calculated pI of 6.6. Secondary-structure predictions identified repeated stretches of amphipathic beta-sheets typical of outer membrane protein membrane-spanning sequences. A topological model of Tromp1 containing 14 transmembrane segments is proposed. Specific antiserum against a recombinant Tromp1 fusion protein was generated and was used to identify native Tromp1 in cellular fractionation. Upon Triton X-114 extraction and phase separation of T. pallidum, the 31-kDa Tromp1 protein was detected in the detergent-phase fraction but not in the protoplasmic cylinder or aqueousphase fractions, consistent with a hydrophobic outer membrane protein. Anti-Tromp1 antiserum was also used to identify native Tromp1 purified from whole T. pallidum by Triton X-100 solubilization followed by nondenaturing isoelectric focusing. Reconstitution of purified Tromp1 into planar lipid bilayers showed porin activity based on the measured single channel conductanes of 0.15 and 0.7 nS in 1 M KCl. These findings demonstrate that Tromp1 is a transmembrane outer membrane porin protein of T. pallidum.

Treponemicidal antibody measured by the "washed-killing" assay correlates with immunity in experimental rabbit syphilis

BACKGROUND AND OBJECTIVES

The authors have previously shown that complement-dependent treponemicidal antibody measured by the "washed-killing" assay is directed exclusively against surface-exposed targets on Treponema pallidum, presumably the Treponema pallidum rare outer membrane proteins detected by freeze-fracture electron microscopy.

GOAL OF THIS STUDY

Because immune mechanisms against Treponema pallidum rare outer membrane proteins are likely to be central to a protective host response, it was examined whether a relationship could be established between treponemicidal levels as measured by the "washed-killing" assay and host immunity in experimental syphilis.

STUDY DESIGN

Three groups of Treponema pallidum-infected rabbits were treated curatively with penicillin at 9 days, 30 days, and 6 months post-infection to generate animals with varying degrees of immunity to challenge re-infection. The level of complement-dependent treponemicidal activity in sera obtained before infection (basal) and before intradermal challenge was determined by the "washed-killing" assay and compared with that detected using conventional in vitro immobilization.

RESULTS

Using the "washed-killing" assay, a close quantitative correlation as measured by a treponemal immobilizing endpoint titer was demonstrable between prechallenge treponemicidal antibody and the status of immunity to re-infection. Sera from rabbits completely susceptible to symptomatic and disseminated asymptomatic re-infection lacked treponemicidal antibody. Sera from challenged rabbits with a relatively low degree of immunity to symptomatic disease showed endpoints of < or = 4. Rabbits with a relatively high degree of immunity to symptomatic reinfection and resistant to disseminated disease had endpoints that ranged from 6 to 96. Rabbits completely resistant to challenge exhibited endpoints ranging from 96 to 128.

CONCLUSION

Treponemicidal antibody measured by the "washed-killing" assay correlated closely with the status of immunity in experimental rabbit syphilis. Thus, antibody measured by this assay may be directed against key protective Treponema pallidum surface immunogens.

Isolation of the outer membranes from Treponema pallidum and Treponema vincentii

The outer membranes from Treponema pallidum subsp. pallidum and Treponema vincentii were isolated by a novel method. Purified outer membranes from T. pallidum and T. vincentii following sucrose gradient centrifugation banded at 7 and 31% (wt/wt) sucrose, respectively. Freeze fracture electron microscopy of purified membrane vesicles from T. pallidum and T. vincentii revealed an extremely low density of protein particles; the particle density of T. pallidum was approximately six times less than that of T. vincentii. The great majority of T. vincentii lipopolysaccharide was found in the outer membrane preparation. The T. vincentii outer membrane also contained proteins of 55 and 65 kDa. 125I-penicillin V labeling demonstrated that t. pallidum penicillin-binding proteins were found exclusively with the protoplasmic cylinders and were not detectable with purified outer membrane material, indicating the absence of inner membrane contamination. Isolated T. pallidum outer membrane was devoid of the 19-kDa 4D protein and the normally abundant 47-kDa lipoprotein known to be associated with the cytoplasmic membrane; only trace amounts of the periplasmic endoflagella were detected. Proteins associated with the T. pallidum outer membrane were identified by one- and two-dimensional electrophoretic analysis using gold staining and immunoblotting. Small amounts of strongly antigenic 17- and 45-kDa proteins were detected and shown to correspond to previously identified lipoproteins which are found principally with the cytoplasmic membrane. Less antigenic proteins of 65, 31 (acidic pI), 31 (basic pI), and 28 kDa were identified. Compared with whole-organism preparations, the 65- and the more basic 31-kDa proteins were found to be highly enriched in the outer membrane preparation, indicating that they may represent the T. pallidum rare outer membrane proteins. Reconstitution of solubilized T. pallidum outer membrane into lipid bilayer membranes revealed porin activity with two estimated channel diameters of 0.35 and 0.68 nm based on the measured single-channel conductances in 1 M KCl of 0.40 and 0.76 nS, respectively.