Altered COVID-19 immunity in children with asthma by atopic status

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes a spectrum of clinical outcomes that may be complicated by severe asthma. Antiviral immunity is often compromised in patients with asthma; however, whether this is true for SARS-CoV-2 immunity and children is unknown.

Objective

We aimed to evaluate SARS-CoV-2 immunity in children with asthma on the basis of infection or vaccination history and compared to respiratory syncytial viral or allergen (eg, cockroach, dust mite)-specific immunity.

Methods

Fifty-three children from an urban asthma study were evaluated for medical history, lung function, and virus- or allergen-specific immunity using antibody or T-cell assays.

Results

Polyclonal antibody responses to spike were observed in most children from infection and/or vaccination history. Children with atopic asthma or high allergen-specific IgE, particularly to dust mites, exhibited reduced seroconversion, antibody magnitude, and SARS-CoV-2 virus neutralization after SARS-CoV-2 infection or vaccination. TH1 responses to SARS-CoV-2 and respiratory syncytial virus correlated with antigen-respective IgG. Cockroach-specific T-cell activation as well as IL-17A and IL-21 cytokines negatively correlated with SARS-CoV-2 antibodies and effector functions, distinct from total and dust mite IgE. Allergen-specific IgE and lack of vaccination were associated with recent health care utilization. Reduced lung function (forced expiratory volume in 1 second ≤ 80%) was independently associated with (SARS-CoV-2) peptide-induced cytokines, including IL-31, whereas poor asthma control was associated with cockroach-specific cytokine responses.

Conclusion

Mechanisms underpinning atopic and nonatopic asthma may complicate the development of memory to SARS-CoV-2 infection or vaccination and lead to a higher risk of repeated infection in these children.

Remote assessment of the Penn computerised neurocognitive battery in individuals with 22q11.2 deletion syndrome

BACKGROUND

Neurocognitive functioning is an integral phenotype of 22q11.2 deletion syndrome relating to severity of psychopathology and outcomes. A neurocognitive battery that could be administered remotely to assess multiple cognitive domains would be especially beneficial to research on rare genetic variants, where in-person assessment can be unavailable or burdensome. The current study compares in-person and remote assessments of the Penn computerised neurocognitive battery (CNB).

METHODS

Participants (mean age = 17.82, SD = 6.94 years; 48% female) completed the CNB either in-person at a laboratory (n = 222) or remotely (n = 162).

RESULTS

Results show that accuracy of CNB performance was equivalent across the two testing locations, while slight differences in speed were detected in 3 of the 11 tasks.

CONCLUSIONS

These findings suggest that the CNB can be used in remote settings to assess multiple neurocognitive domains.

Targeting location relates to treatment response in active but not sham rTMS stimulation

Background:

Precise targeting of brain functional networks is believed critical for treatment efficacy of rTMS (repetitive pulse transcranial magnetic stimulation) in treatment resistant major depression.

Objective:

To use imaging data from a “failed” clinical trial of rTMS in Veterans to test whether treatment response was associated with rTMS coil location in active but not sham stimulation, and compare fMRI functional connectivity between those stimulation locations.

Methods:

An imaging substudy of 49 Veterans (mean age, 56 years; range, 27e78 years; 39 male) from a randomized, sham-controlled, double-blinded clinical trial of rTMS treatment, grouping participants by clinical response, followed by group comparisons of treatment locations identified by individualized fiducial markers on structural MRI and resting state fMRI derived networks.

Results:

The average stimulation location for responders versus nonresponders differed in the active but not in the sham condition (P = .02). The average responder location derived from the active condition showed significant negative functional connectivity with the subgenual cingulate (P < .001) while the nonresponder location did not (P = .17), a finding replicated in independent cohorts of 84 depressed and 35 neurotypical participants. The responder and nonresponder stimulation locations evoked different seed based networks (FDR corrected clusters, all P < .03), revealing additional brain regions related to rTMS treatment outcome.

Conclusion:

These results provide evidence from a randomized controlled trial that clinical response to rTMS is related to accuracy in targeting the region within DLPFC that is negatively correlated with subgenual cingulate. These results support the validity of a neuro-functionally informed rTMS therapy target in Veterans.

Everyday Multitasking Abilities in Older HIV+ Adults: Neurobehavioral Correlates and the Mediating Role of Metacognition

Objective

The prevalence of older adults living with HIV is rising, as is their risk for everyday functioning problems associated with neurocognitive dysfunction. Multitasking, the ability to maintain and carry out subgoals in support of a larger goal, is a multidimensional skill ubiquitous during most real-life tasks and associated with prefrontal networks that are vulnerable in HIV. Understanding factors associated with multitasking will improve characterization of HIV-associated neurocognitive disorders. Metacognition is also associated with frontal systems, is impaired among individuals with HIV, and may contribute to multitasking.

Method

Ninety-nine older (≥50 years) adults with HIV completed: the Everyday Multitasking Test (MT), a performance-based measure during which participants concurrently attempt four everyday tasks (e.g., medication management) within a time limit; a comprehensive neuropsychological battery; measures of metacognition regarding their MT performance (e.g., metacognitive knowledge and online awareness).

Results

Better global neuropsychological performance (i.e., average T-score across all domains) was associated with better Everyday MT total scores (rho = 0.34; p < .001), as was global metacognition (rho = 0.37, p < .01). Bootstrapping mediation analysis revealed global metacognition was a significant partial mediator between neurocognition and Everyday MT (b = 0.09, 95% confidence interval [CI] = 0.01, 0.25). Specifically, metacognitive knowledge (but not online awareness) drove this mediation (b = 0.13, 95% CI = 0.03, 0.27).

Conclusions

Consistent with findings among younger persons with HIV, neuropsychological performance is strongly associated with a complex, laboratory-based test of everyday multitasking, and metacognition of task performance was a pathway through which successful multitasking occurred. Interventions aimed at modifying metacognition to improve daily functioning may be warranted among older adults with HIV.

Feasibility and Acceptability of Ecological Momentary Assessment of Daily Functioning Among Older Adults with HIV

OBJECTIVE

This study aimed to examine the feasibility, acceptability, and initial validity of using smartphone-based ecological momentary assessment (EMA) to assess daily functioning and other behavioral factors among older HIV+ adults.

METHODS

Twenty older HIV+ adults (mean age: 59 years) completed laboratory-based neurobehavioral and functional assessments then completed EMA surveys via smartphones five times per day for one week.

RESULTS

Excellent EMA adherence (86.4%) was found, and participants rated their experience with EMA methods positively. Time-use data indicated participants were spending 74% of their waking-sampled time at home, 63% of their time alone, and 32% of their time engaged in passive leisure activities (e.g., watching TV). Better neurocognitive and functional capacity abilities were correlated with less time spent in passive leisure activities. Lastly, mood and cognitive symptom data collected via EMA were significantly associated with scores from laboratory-based assessments of these same constructs.

CONCLUSIONS

EMA via smartphones is a feasible and acceptable data collection method among older HIV+ adults and appears to be a promising mobile tool to assess daily functioning behaviors in HIV. These preliminary findings indicate older HIV+ adults are spending a considerable amount of time at home, alone, and engaged in passive leisure activities, primarily watching TV. EMA may contribute to future research examining functional disability among the growing population of older HIV+ adults.

Anterior hippocampal dysconnectivity in posttraumatic stress disorder: a dimensional and multimodal approach

The anterior hippocampus (aHPC) has a central role in the regulation of anxiety-related behavior, stress response, emotional memory and fear. However, little is known about the presence and extent of aHPC abnormalities in posttraumatic stress disorder (PTSD). In this study, we used a multimodal approach, along with graph-based measures of global brain connectivity (GBC) termed functional GBC with global signal regression (f-GBCr) and diffusion GBC (d-GBC), in combat-exposed US Veterans with and without PTSD. Seed-based aHPC anatomical connectivity analyses were also performed. A whole-brain voxel-wise data-driven investigation revealed a significant association between elevated PTSD symptoms and reduced medial temporal f-GBCr, particularly in the aHPC. Similarly, aHPC d-GBC negatively correlated with PTSD severity. Both functional and anatomical aHPC dysconnectivity measures remained significant after controlling for hippocampal volume, age, gender, intelligence, education, combat severity, depression, anxiety, medication status, traumatic brain injury and alcohol/substance comorbidities. Depression-like PTSD dimensions were associated with reduced connectivity in the ventromedial and dorsolateral prefrontal cortex. In contrast, hyperarousal symptoms were positively correlated with ventromedial and dorsolateral prefrontal connectivity. We believe the findings provide first evidence of functional and anatomical dysconnectivity in the aHPC of veterans with high PTSD symptomatology. The data support the putative utility of aHPC connectivity as a measure of overall PTSD severity. Moreover, prefrontal global connectivity may be of clinical value as a brain biomarker to potentially distinguish between PTSD subgroups.

Abbreviated Goal Management Training Shows Preliminary Evidence as a Neurorehabilitation Tool for HIV-associated Neurocognitive Disorders among Substance Users

OBJECTIVE

Substance use disorders are highly comorbid with and contribute to the increased prevalence of neurocognitive dysfunction observed in HIV infection. Despite their adverse impact on everyday functioning, there are currently no compensatory-based neurorehabilitation interventions validated for use among HIV+ substance users (HIV/SUD). This study examined the effectiveness of goal management training (GMT) alone or GMT as part of a metacognitive training among HIV/SUD individuals with executive dysfunction.

METHODS

Ninety HIV/SUD individuals were randomized to a single 15-min session: (1) GMT (n = 30); (2) GMT plus metacognitive training (neurocognitive awareness; GMT + Meta; n = 30); or (3) active control (n = 30). Following a brief neurocognitive battery and study condition, participants performed a complex laboratory-based function task, Everyday Multitasking Test (Everyday MT), during which metacognition (awareness) was evaluated.

RESULTS

There was an increasing, but non-significant tendency for better Everyday MT performances across study conditions (Control ≤ GMT ≤ GMT + Meta; ps < .08). Post hoc analyses showed that GMT and GMT + Meta groups demonstrated small benefits (d = .20-.27) compared to the control arm but did not differ from one another (ds < .10). When GMT groups were combined, there were significant medium effect size benefits in Everyday MT performance and metacognitive task appraisals as compared to the control condition. Among participants who underwent GMT, benefits were most prominent in persons with poorer pre-training dual-tasking ability, depression, and methamphetamine use disorders (ds = .35-1.04).

CONCLUSIONS

A brief compensatory strategy has benefits for everyday multitasking and metacognition among HIV+ substance users with executive dysfunction. Future work exploring more intensive trainings, potentially complimentary to other restorative approaches and/or pharmacological treatments, is warranted.

Group patient visits for Parkinson disease: a randomized feasibility trial

BACKGROUND

Group patient visits are medical appointments shared among patients with a common medical condition. This care delivery method has demonstrated benefits for individuals with chronic conditions but has not been evaluated for Parkinson disease (PD).

METHODS

We conducted a 12-month, randomized trial of group patient visits vs usual (one-on-one) care for patients with PD. Visits were led by one of 3 study physicians, included patients and caregivers, and lasted approximately 90 minutes. Those receiving group visits had 4 sessions over 12 months. The primary outcome measure was feasibility as measured by the ability to recruit participants and by the proportion of participants who completed the study. The primary efficacy outcome was quality of life as measured by the PD Questionnaire-39.

RESULTS

Thirty patients and 27 caregivers enrolled in the study. Thirteen of the 15 patients randomized to group patient visits and 14 of the 15 randomized to usual care completed the study. Quality of life measured 12 months after baseline between the 2 groups was not different (25.9 points for group patient visits vs 26.0 points for usual care; p = 0.99).

CONCLUSIONS

Group patient visits may be a feasible means of providing care to individuals with PD and may offer an alternative or complementary method of care delivery for some patients and physicians.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that group patient visits did not improve quality of life for individuals with PD over a 1-year period.

Effect of Temperature on Severity of Fusarium Wilt of Lettuce Caused by Fusarium oxysporum f. sp. lactucae

The effect of temperature on Fusarium wilt of lettuce (Lactuca sativa), caused by Fusarium oxysporum f. sp. lactucae, was examined in a controlled environment. Nine lettuce cultivars planted in infested potting mix (500 or 5,000 CFU/g) were maintained under high/low diurnal temperature regimes of 26/18°C, 28/20°C, or 33/26°C. Three cultivars were resistant to Fusarium wilt under all test conditions, and thus were little affected by differences in inoculum level or temperature. The remaining cultivars were more susceptible and manifested more severe symptoms at the higher inoculum level and when maintained at higher temperatures. The tendency for the disease to be more severe under warmer conditions may be due, in part, to an effect of temperature on growth of the pathogen. Radial growth rates calculated for six isolates of F. oxysporum f. sp. lactucae were observed to increase from 10°C up to an apparent maximum near 25°C. The results of this study suggest that growers can reduce the risk of damage from Fusarium wilt by avoiding susceptible cultivars during the warmest planting periods. Further, isolates of F. oxysporum f. sp. lactucae were shown to have a distinctive colony morphology in culture, which made it possible to distinguish them from nonpathogenic strains.

Molecular and immunological characterisation of a polymorphic cytosolic fatty acid binding protein from the human blood fluke of humans, Schistosoma japonicum

Most organisms obtain their fatty acids through their diet or by de novo synthesis, but human blood flukes belonging to the genus Schistosoma lack the oxygen-dependent pathways required for the synthesis of sterols and fatty acids so they are entirely dependent on their hosts for these and other complex lipids. Fatty acid binding proteins (FABPs) of the FABP/P2/CRABP/CRBP family of beta-barrel cytosolic lipid binding proteins (cLBP) appear to be particularly important to schistosomes in the uptake, transport and compartmentalisation of host-derived fatty acids and may provide important targets for immuno- and chemotherapy. Here we describe the isolation of a set of cDNAs prepared from the Asiatic schistosome, Schistosoma japonicum, which encode two groups of cLBPs based on sequence homology and unique cDNA restriction sites. Representative clones from the two groups, one encoding a complete Sj-FABP (F10), and the other encoding a deletion mutant (F25) were characterised at the nucleic acid level by Southern and Northern hybridisation analysis, and at the protein level by immunoblotting. The presence and size of introns in the genes encoding F10 and F25 were determined and, because of the interest in the Schistosoma mansoni FABP homologue (Sm14) as a putative vaccine candidate, the immunogenicity and protective efficacy of the two proteins were also evaluated. A particularly interesting finding was the degree of Sj-FABP amino acid sequence polymorphism found to occur within the S. japonicum worm population, which appears to be greater than that described from cLBPs from vertebrates or, indeed, any other group of organisms investigated to date.

Molecular cloning and enzymatic expression of the 28-kDa glutathione S-transferase of Schistosoma japonicum: evidence for sequence variation but lack of consistent vaccine efficacy in the murine host

Glutathione S-transferases (GSTs) have long been regarded as attractive vaccine (and drug) targets in schistosomes due to their suspected role in detoxification processes. Indeed, the 28-kDa GST of Schistosoma mansoni (SmGST28) has proven efficacy as an antigen for protective immunity reducing worm burden, female fecundity and egg viability. In contrast, the vaccinating effects of the bacterial expressed homologue of Philippine S. japonicum (SjpGST28) have proved disappointing, possibly because this recombinant form was an incomplete sequence, lacking five N-terminal amino acids which may have affected its vaccination efficacy. Here we describe the cloning and functional enzymatic expression of a complete cDNA encoding SjpGST28. We report also on the immunogenicity and vaccine efficacy of this molecule as a purified recombinant protein and as a DNA plasmid vaccine in the murine model. We further describe the cloning of several complete cDNAs encoding the Chinese homologue of SjpGST28 and the identification of 3 SjcGST28 sequence variants which are probably encoded by distinct alleles.

Sj-FABPc fatty-acid-binding protein of the human blood fluke Schistosoma japonicum: structural and functional characterization and unusual solvent exposure of a portal-proximal tryptophan residue

Sj-FABPc of the blood fluke of humans, Schistosoma japonicum, is a member of the FABP/P2/CRBP/CRABP family of beta-barrel cytosolic fatty-acid-binding and retinoid-binding proteins. Sj-FABPc has at least eight different variants encoded by a single-copy polymorphic gene. In fluorescence-based assays, recombinant Sj-FABPc was found to bind 11-(dansylamino)undecanoic acid (DAUDA), inducing a shift in peak fluorescence emission from 543 to 493 nm. A similar spectral change was observed in dansyl-amino-octanoic acid (in which the dansyl fluorophore is attached at the alpha-carbon rather than the omega-carbon of DAUDA), indicating that the ligand enters entirely into the binding site. Sj-FABPc also bound the naturally fluorescent cis-parinaric acid, as well as oleic acid and arachidonic acid, by competition, but not all-trans-retinol. Dissociation constants were, for cis-parinaric acid, K(d)=2.5+/-0.1 microM (mean+/-S.E.M.) and an apparent stoichiometry consistent with one binding site per molecule of Sj-FABPc and, for oleic acid, K(i) approximately 80 nM. A deletion mutant from which alpha-II was absent failed to bind ligand. Sj-FABPc modelled well to known structures of the protein family; an unusually solvent-exposed Trp side chain was evident adjacent to the presumptive portal through which ligand is thought to enter and leave. Intrinsic fluorescence analyses of Sj-FABPc and of the deletion mutant (from which Trp-27 is absent) confirmed the unusual disposition of this side chain. Virtually all members of the FABP/P2/CRBP/CRABP protein family have prominent hydrophobic side chains in this position, with the exception of liver FABP and ileal FABP, which instead have charged side chains. Liver FABP is known to be distinct from other members of the protein family in that it does not seem to contact membranes to collect and deposit its ligand. It is therefore postulated that the unusually positioned apolar side chains in Sj-FABPc and others in the family are important in interactions with membranes or other cellular components.

Characterisation and expression of a cDNA encoding the 80-kDa large subunit of Schistosoma japonicum calpain

We describe the cloning of a full length calpain-encoding cDNA constructed from two truncated cDNAs isolated from a cDNA library prepared with mRNA isolated from adult worms of the Philippine strain of Schistosoma japonicum. The cDNA sequence is 2.456 kb in length and predicts a protein of 758 residues with a molecular mass of 86.61 kDa and an isoelectric point of 5.34. Probes spanning the entire calpain cDNA hybridised to multiple bands in genomic DNAs of Philippine (SjP) and Chinese (SjC) S. japonicum, with some restriction fragment length polymorphisms evident between the two strains. Northern hybridisation analysis indicated that the cDNA codes for a single RNA transcript between 2.6 and 3.6 kb in size in the SjP and SjC genomes. After subcloning in the QIA express vectors pQE-31 and pQE-40 and subsequent expression, the recombinant protein was purified and shown to bind calcium. The availability of recombinant S. japonicum calpain will allow its future evaluation as a vaccine candidate, especially in light of recent work with the S. mansoni homologue which has provided evidence that this protein may be a target of protective immunity.

Risk of mortality following clinical fractures

To examine the risk of mortality following all clinical fractures, we followed 6459 women age 55-81 years participating in the Fracture Intervention Trial for an average of 3.8 years. All fractures and deaths were confirmed by medical record or death certificate. Clinical fractures were fractures that came to medical attention. Fracture status was used as a time-dependent covariate in proportional hazards models. The 907 women who experienced a fracture were older, had lower bone mineral density and were more likely to report a positive fracture history. A total of 122 women died over the course of the study with 23 of these deaths occurring after a clinical fracture. The age-adjusted relative risk (95% confidence intervals) of dying following a clinical fracture was 2.15 (1.36, 3.42). This primarily reflected the higher mortality following a hip fracture, 6.68 (3.08, 14.52); and clinical vertebral fracture, 8.64 (4.45, 16.74). Results were similar after adjusting for treatment assignment, health status and specific common comorbidities. There was no increase in mortality following a forearm or other fracture (non-hip, non-wrist, nonvertebral fracture). In conclusion, clinical vertebral fractures and hip fractures are associated with a substantial increase in mortality among a group of relatively healthy older women.

A low-cost approach to prospective identification of impending high cost outcomes

OBJECTIVES

The overall objective of this study was to define and evaluate patterns of use of medical services in the care of patients with chronic illness that represent circumstances which, if modified, might lead to reduction in risk of acute-level care.

METHODS

This was a retrospective observational study. The study population consisted of Kaiser Permanente enrollees at four sites during January 1993 through June 1995, who were 20 to 64 years of age and had two of three chronic diseases (diabetes, circulatory disorders, obstructive pulmonary disorders). Using logistic regression, the effect of primary care visit patterns and therapeutically risky drug combinations on likelihood of hospital admission in a subsequent 3-month period is adjusted for age, gender, and disease state in the prior 12-month period.

RESULTS

Enrollees with visits to three or more different primary care physicians were 46% more likely to be admitted than expected (P < 0.01) according to their age, gender, and disease state, and those with therapeutically risky drug combinations were 34% more likely to be admitted (P < 0.01).

CONCLUSIONS

The risk adjustment models evaluated in this study defined care processes associated with increased risk of subsequent acute-level services. Those processes may represent nascent acute disease states or suboptimal organization of care delivery. The results of these models can be used to inform changes in organization and delivery of outpatient care that might improve patient outcomes.

Osteoarthritis and risk of falls, rates of bone loss, and osteoporotic fractures. Study of Osteoporotic Fractures Research Group

OBJECTIVE

To examine the association between osteoarthritis (OA), as defined by radiographic evidence and self report, and osteoporotic fractures, falls, and bone loss in a cohort of elderly white women.

METHODS

A cohort of 5,552 elderly women from the Study of Osteoporotic Fractures was followed up prospectively for a mean of 7.4 years. Self-reported, physician-diagnosed OA was recorded at interview, and radiologic OA of the hip and hand were defined from pelvis and hand radiographs obtained at baseline by validated techniques. Prevalent and incident vertebral fractures were detected by vertebral morphometry, and data on incident fractures and falls were collected by postcard surveys; fractures were confirmed by radiography. Bone mineral density (BMD) was measured on 2 occasions at the hip, lumbar spine, and calcaneus, and rates of bone loss were calculated.

RESULTS

Women with radiographic hip OA had a reduced risk of recurrent falls in the first year (relative risk [RR] 0.7, 95% confidence interval [95% CI] 0.5-0.95). However, those with self-reported OA had an increased risk of falls (RR 1.4, 95% CI 1.2-1.5). Radiographic hip OA was associated with reduced bone loss in the femoral neck compared with controls (mean +/- SD -0.29+/-0.09%/year versus -0.51+/-0.03%/year; P = 0.018). However, radiographic hip OA showed nonsignificant trends toward increased bone loss at the calcaneus and lumbar spine. There was no significant association between self-reported OA or radiographic hand OA with bone loss. No definition of OA was associated with incident nonvertebral fracture, hip fracture, or vertebral fracture.

CONCLUSION

Despite having increased BMD compared with controls, subjects with OA did not have a significantly reduced risk of osteoporotic fracture, although there was a trend toward a reduced risk of femoral neck fractures in subjects with severe radiographic OA. The failure of the observed increase in BMD to translate into a reduced fracture risk may be due, in part, to the number and type of falls sustained by subjects with OA. Patients with OA should not be considered to be at a lower risk of fracture than the general population. Physicians should be aware that a high BMD in patients with OA may be falsely reassuring.

Serum vitamin D levels and incident changes of radiographic hip osteoarthritis: a longitudinal study. Study of Osteoporotic Fractures Research Group

OBJECTIVE

The purpose of this study was to determine the relationship of serum levels of 25-vitamin D and 1,25-vitamin D to incident changes of radiographic hip osteoarthritis (OA) among elderly white women.

METHODS

Baseline and followup hip radiographs of 237 subjects were obtained an average of 8 years apart. Hips were scored for individual radiographic features (IRF) and assigned a summary grade based on the number and type of IRF present. Serum 25- and 1,25-vitamin D levels from baseline samples were analyzed by radioimmunoassay. Logistic and linear regression were used to examine the association of 25- and 1,25-vitamin D levels with radiographic changes, adjusting for age, health status, physical activity, weight, vitamin D supplement use, and calcaneal bone mineral density.

RESULTS

The risk of incident hip OA defined as the development of definite joint space narrowing was increased for subjects who were in the middle (odds ratio [OR] 3.21, 95% confidence interval [95% CI] 1.06, 9.68) and lowest (OR 3.34, 95% CI 1.13, 9.86) tertiles for 25-vitamin D compared with subjects in the highest tertile. Vitamin D levels were not associated with incident hip OA defined as the development of definite osteophytes or new disease according to the summary grade. No association between serum 1,25-vitamin D and changes in radiographic hip OA was found.

CONCLUSION

Low serum levels of 25-vitamin D may be associated with incident changes of radiographic hip OA characterized by joint space narrowing.

Telemedicine in Micronesia

Distance and isolation profoundly affect the delivery of health care in the islands of Micronesia. The lack of specialty services on most of the islands has led to a costly off-island referral system that strains health care budgets. Care providers there have incorporated advances in telecommunications to create a telemedicine network amongst themselves and with a tertiary care hospital in Hawaii. They developed an interactive video conferencing system, a still-image transmission network, and a data transfer network for use principally in patient care and continuing education. Patients now receive earlier evaluation by off-island specialists as part of an effort to improve the appropriateness of off-island referrals. Regularly scheduled medical lectures are broadcast from Pohnpei, a main island, to physicians in several more remote locations. Transmission costs are kept low by using, when possible, preexisting public-service satellites, such as the PEACESAT system that serves the entire Pacific basin. The telemedicine system is evolving, and its success depends greatly on the cooperative relationships among the partners.

Recreational physical activity and the risk of osteoarthritis of the hip in elderly women

OBJECTIVE

The relationship between recreational physical activity and the risk of osteoarthritis (OA) of the hip in women is uncertain. We examined the cross sectional association of radiographic OA of the hip and past recreational and sports related physical activity in elderly women who are participants in the Study of Osteoporotic Fractures.

METHODS

An anteroposterior pelvic radiograph of 5818 subjects was assessed for hip OA using reliable measurements of individual radiographic features. Hips were graded on a summary scale of 0 (no findings) to 4 (severe OA) based on the number and type of radiographic features present. Logistic regression was used to examine the association of self-reported recreational physical activity (times/week) as a teenager, at age 30, and at age 50 with hip OA. All analyses were adjusted for age and body mass index at age 25 years.

RESULTS

The risk of moderate to severe radiographic hip OA in elderly women was modestly increased in elderly women who were in the highest quartile for all physical activities performed as a teenager (odds ratio 1.7, 95% confidence interval 1.1, 2.4), at age 50 (OR 1.4, 95% CI 1.0, 1.9) and weight bearing activities at age 30 (OR 1.4, 95% CI 1.0, 1.9) compared to women in the lowest quartile of activity. The risk of symptomatic hip OA (grade > or =2 hip OA + hip pain) was modestly increased in women who were in the highest quartile for all physical activities as a teenager (OR 2.0, 95% CI 1.2, 3.4), at age 50 (OR 1.6, 95% CI 1.0, 2.4), and weight bearing activities at age 30 (OR 1.6, 95% CI 1.0, 2.4) compared to women in the lowest quartile of activity.

CONCLUSION

Recreational physical activities performed by women before menopause may increase the risk of radiographic and symptomatic hip OA.

Molecular cloning and functional expression of a cDNA encoding the major endoplasmic reticulum-associated calcium-binding protein, calreticulin, from Philippine strain Schistosoma japonicum

We describe the cloning of a full length calreticulin (CR)-encoding cDNA clone isolated by immunoscreening of a cDNA library prepared with mRNA from adult worms of the Philippine strain of Schistosoma japonicum, the cause of Asian schistosomiasis. The sequence of the cDNA is presented, and its molecular characterisation and functional expression as a Ca2+-binding protein described. The potential role of CR in inducing protective immunity in the schistosomes is discussed.

Identification of novel 70-kDa heat shock protein-encoding cDNAs from Schistosoma japonicum

A diverse range of organisms respond to a variety of chemical, physiological and temperature-associated stresses by a rapid and transient increase in the synthesis of heat shock proteins. We immunoscreened a Uni-ZAP XR cDNA library, prepared from mRNA isolated from the Philippine strain of the Asian bloodfluke, Schistosoma japonicum, using hyperimmune rabbit sera raised against soluble adult S. japonicum proteins. Six 70-kDa heat shock protein-encoding cDNA clones were identified which, upon further analysis, were separated into two distinct protein groups within the 70-kDa heat shock protein family, the 70-kDa heat shock proteins and the immunoglobulin heavy chain-binding proteins/glucose-related proteins (Grp78). A representative from both groups was fully sequenced and compared with homologous sequences available in the GenBank/EMBL database as the first stage in determining the role of their expression products in the regulation of S. japonicum development, in the induction of immunity, and whether they act as molecular chaperones capable of modulating the correct folding or repair of proteins within this species of schistosome.

Characterization of the rat adrenal medulla cultured in vitro

A wide variety of experimental animal models have been used to investigate the mechanisms of synthesis, storage, and release of catecholamines. Whereas in vivo experimental models are situated at one end of the spectrum, cell culture models are situated at the other end. In the present study, we have characterized various aspects of the rat adrenal medulla cultured in vitro as a whole tissue, aiming to establish a new experimental model in between in vivo animal models and cell culture models. We adapted a bottle rotator system commonly used for culturing rodent whole embryos. Changes in histology, activities and mRNA levels of catecholamine-synthesizing enzymes, and concentrations of catecholamines in the adrenal medulla were studied. In addition, the effects of cholinergic stimulation on catecholamine release from the adrenal medulla were examined. Overall the results indicate that various aspects of the adrenal medulla become stable after 4 d of culture and the adrenal medulla at this stage releases catecholamines in response to cholinergic stimulation. The whole adrenal medulla culture system may be a useful tool for investigating catecholamine-related functions dependent on intercellular reactions or communications.

Effect of alendronate on risk of fracture in women with low bone density but without vertebral fractures: results from the Fracture Intervention Trial

CONTEXT

Alendronate sodium reduces fracture risk in postmenopausal women who have vertebral fractures, but its effects on fracture risk have not been studied for women without vertebral fractures.

OBJECTIVE

To test the hypothesis that 4 years of alendronate would decrease the risk of clinical and vertebral fractures in women who have low bone mineral density (BMD) but no vertebral fractures.

DESIGN

Randomized, blinded, placebo-controlled trial.

SETTING

Eleven community-based clinical research centers.

SUBJECTS

Women aged 54 to 81 years with a femoral neck BMD of 0.68 g/cm2 or less (Hologic Inc, Waltham, Mass) but no vertebral fracture; 4432 were randomized to alendronate or placebo and 4272 (96%) completed outcome measurements at the final visit (an average of 4.2 years later).

INTERVENTION

All participants reporting calcium intakes of 1000 mg/d or less received a supplement containing 500 mg of calcium and 250 IU of cholecalciferol. Subjects were randomly assigned to either placebo or 5 mg/d of alendronate sodium for 2 years followed by 10 mg/d for the remainder of the trial.

MAIN OUTCOME MEASURES

Clinical fractures confirmed by x-ray reports, new vertebral deformities detected by morphometric measurements on radiographs, and BMD measured by dual x-ray absorptiometry.

RESULTS

Alendronate increased BMD at all sites studied (P<.001) and reduced clinical fractures from 312 in the placebo group to 272 in the intervention group, but not significantly so (14% reduction; relative hazard [RH], 0.86; 95% confidence interval [CI], 0.73-1.01). Alendronate reduced clinical fractures by 36% in women with baseline osteoporosis at the femoral neck (>2.5 SDs below the normal young adult mean; RH, 0.64; 95% CI, 0.50-0.82; treatment-control difference, 6.5%; number needed to treat [NNT], 15), but there was no significant reduction among those with higher BMD (RH, 1.08; 95% CI, 0.87-1.35). Alendronate decreased the risk of radiographic vertebral fractures by 44% overall (relative risk, 0.56; 95% CI, 0.39-0.80; treatment-control difference, 1.7%; NNT, 60). Alendronate did not increase the risk of gastrointestinal or other adverse effects.

CONCLUSIONS

In women with low BMD but without vertebral fractures, 4 years of alendronate safely increased BMD and decreased the risk of first vertebral deformity. Alendronate significantly reduced the risk of clinical fractures among women with osteoporosis but not among women with higher BMD.

Differential antigen-stimulated proliferation of human mononuclear cells by recombinant Schistosoma japonicum antigens in a Chinese population

Peripheral blood mononuclear cells (PBMC) from 117 individuals living on two islands in an area (Dongting Lake) endemic for schistosomiasis japonica in China, and 15 control individuals from a non-endemic area of China, were assessed for antigen-stimulated proliferation against five recombinant Schistosoma japonicum antigens of recognized interest in the development of immunity to schistosomiasis. Two recombinant antigens, paramyosin and 28-kD glutathione-S-transferase, stimulated cellular proliferation (stimulation index > or = 3.0) in 38.5% and 42.5% of subjects, respectively, a level similar to that induced by a soluble whole parasite extract (51.3%). In contrast, three other recombinant antigens tested--a fatty acid binding protein, 22-kD tegumental membrane-associated antigen, and glyceraldehyde-3-phosphate dehydrogenase--stimulated PBMC proliferation in only 3-8% of subjects. Moreover, we also identified a positive association between the degree of exposure, and cellular proliferation following stimulation with recombinant paramyosin or whole parasite extract. Highly significant differences in antigen-stimulated proliferation were also observed between the two islands, Niangashan and Qingshan. The whole parasite extract stimulated proliferation in 90% of subjects from Niangashan island compared with only 42.1% of subjects from Qingshan island (chi2 = 16.88, P = 0.00004), while glutathione-S-transferase stimulated proliferation in 77.3% of subjects from Niangashan island compared with only 34.7% of subjects from Qingshan island (chi2 = 13.09, P = 0.003). A similar, but not significant, trend was observed for paramyosin and the fatty-acid binding protein. The identification of differential cellular proliferative responses to specific schistosome antigens within an infected human population may have important practical implications for vaccine development against schistosomiasis japonica.

Mapping of linear B-cell epitopes on the 14-kDa fatty-acid binding protein of Chinese Schistosoma japonicum

The 14-kDa fatty-acid binding protein (FABP) of schistosomes is of recognised importance as a potential vaccine and/or drug target against schistosomiasis, but little is known of its antigenicity. In this study, we have identified and compared linear B-cell epitopes present on the FABP of Chinese strain Schistosoma japonicum, using sera obtained from experimentally infected mice, or from mice immunised with the functionally active recombinant antigen (rSjFABP). Sera from three strains of mice, CBA, C57BL/6 and BALB/c, representing different genetic backgrounds, were reacted with a series of overlapping peptides in epitope-scanning studies. Sera from experimentally infected mice reacted predominantly with peptides 9-12, encoding amino acids 91-132, in the C-terminal region of the molecule. This was in contrast to sera from mice immunised with rSjFABP, which reacted predominantly with peptides 4-9, encoding amino acids 41-101, in the central portion of the molecule. The results presented here describing the epitope mapping of this molecule may prove important in research aimed at further defining immune responses to schistosomal antigens. They indicate that epitopes recognised during vaccination with functionally active rSjFABP, at least in the murine model, differ from those recognised during natural infection.

Gene expression of catecholamine synthesizing enzymes and beta adrenoceptor subtypes during rat embryogenesis

Timed-pregnant Sprague-Dawley rats were killed between gestational day (GD) 8 and 10, and embryos were explanted and separated into developmental stages according to a modified Theiler's system. Total RNA from each stage was isolated and subjected to reverse transcription-polymerase chain reaction (RT-PCR) assays to examine gene expression of catecholamine synthesizing enzymes and three subtypes of beta adrenoceptors. Expression of these genes was detected at much earlier stages than previously reported, and each enzyme and receptor subtype showed a different pattern of gene expression. For example, mRNA for tyrosine hydroxylase, the rate-limiting enzyme for catecholamine synthesis, was detected as early as stage 10a, late GD 8, before the neural crest cells appear (stage 12, mid GD 10). This contradicts the common belief that catecholamines are produced only in the cells of sympathoadrenal lineage which originate from the neural crest cells and the cells of central nervous system. Results from the present study indicate that catecholamine synthesis is not limited to the cells of sympathoadrenal lineage.

DNA-based vaccination using Schistosoma japonicum (Asian blood-fluke) genes

We have examined the efficacy of nucleic acid vaccination in inducing immunity to the multicellular parasite, Schistosoma japonicum, a trematode worm responsible for causing schistosomiasis in humans and other mammalian species. A panel of Schistosoma japonicum cDNAs were cloned into eukaryotic expression vectors, injected into animals, and tested for immunogenicity. The cDNAs tested encoded 26- and 28-kDa glutathione-S-transferases, calreticulin, glyceraldehyde-3-phosphate dehydrogenase, a 22.6 kDa membrane-associated antigen, a 14 kDa fatty-acid binding protein, fragments of paramyosin, full-length paramyosin, and a novel gene comprising the 26 kDa glutathione-S-transferase fused to a fragment of paramyosin cDNA. The paramyosin gene constructs, including the fusion, were all able to induce anti-paramyosin antibodies; with the fragments of paramyosin these were of the IgG1, IgG2a and IgG2b isotypes. In contrast, none of the other schistosome cDNAs tested were able to induce detectable antibody responses. The anti-paramyosin antibodies did not protect mice challenged with cercariae of S. japonicum.

Kaiser Colorado's Cooperative Health Care Clinic: a group approach to patient care

A Kaiser Permanente pilot project demonstrates that managing health status with patients on a group basis versus one-on-one office visits can improve health care delivery services and reduce unnecessary resource utilization. Kaiser's Cooperative Health Care Clinic (CHCC) in Denver, Colorado, uses a multidisciplinary team to successfully provide care to elderly members with chronic conditions.

Molecular genetic analysis of human cystic hydatid cases from Poland: identification of a new genotypic group (G9) of Echinococcus granulosus

We have used nuclear (ribosomal ITS1) and mitochondrial (ND1) sequences to characterize human and pig isolates of Echinococcus granulosus collected by fine needle aspiration biopsy (FNAB) in Poland. The data indicate clearly that the Polish patients were not infected with the common sheep strain (G1 genotype) of E. granulosus, normally associated with human cystic hydatid infection. Instead, the hydatid parasite infecting the Polish patients shares very similar ND1 sequence with the previously characterized pig (G7) genotype but it also exhibits some clear differences. In particular, E. granulosus DNA from the Polish patients amplified a single ITS1 fragment in PCR and distinct ITS1-RFLP patterns were obtained after restriction digestion. The form of hydatid isolated from the Polish patients appears, therefore, to represent a distinct, previously undescribed genotype (designated G9) of E. granulosus.

Validity of self-reported rheumatoid arthritis in elderly women

OBJECTIVE

To determine the validity of a self-reported physician diagnosis of rheumatoid arthritis (RA) in elderly women.

METHODS

Women with self-reported RA were contacted and permission requested to contact their physician. Physicians were mailed a questionnaire requesting information on the subject's arthritic condition. Hand radiographs obtained at study entry were read for changes of RA.

RESULTS

The self-reported diagnosis of RA could be confirmed in 26 (21%) individuals.

CONCLUSION

The positive predictive value of self-reported RA was low in this cohort. Caution needs to be exercised in the use and interpretation of self-report data concerning arthritic conditions in epidemiologic studies.

Association of estrogen replacement therapy with the risk of osteoarthritis of the hip in elderly white women. Study of Osteoporotic Fractures Research Group

OBJECTIVE

To determine whether postmenopausal estrogen replacement therapy is associated with a reduced risk of radiographic findings of osteoarthritis (OA) of the hip.

DESIGN

Cross-sectional study.

SUBJECTS

White women (N = 4366; age, > or = 65 years) who were participants in a cohort study of osteoporotic fractures.

MEASUREMENTS AND METHODS

Radiographs of the pelvis that were obtained in all subjects were assessed for radiographic features of OA of the hip on a summary scale of 0 (none) to 4 (severe OA). Postmenopausal estrogen use was assessed by interview. The association of current and past oral estrogen use with OA of the hip was analyzed by using logistic regression, adjusting for potential confounding variables (eg, indicators of osteoporosis and correlates of estrogen use).

RESULTS

Five hundred thirty-nine women (12.3%) had mild or greater radiographic findings of OA of the hip in at least 1 hip, and 214 women (4.9%) had moderate to severe findings; 17% and 24% of the women were current and past users of oral estrogen, respectively. Women who were currently using oral estrogen had a significantly reduced risk of any OA of the hip (adjusted odds ratio [OR], 0.62; 95% confidence interval [CI], 0.49-0.86) and moderate to severe manifestation of disease (OR, 0.54; 95% CI, 0.33-0.88). Current users who had taken estrogen for 10 years or longer had a greater reduction in the risk of any OA of the hip (OR, 0.57; 95% CI, 0.40-0.82) compared with that of users for less than 10 years (OR, 0.75; 95% CI, 0.47-1.24). Current estrogen use for 10 years or longer was associated with a nonsignificant trend for a reduced risk of moderate to severe symptomatic disease (OR, 0.59; 95% CI, 0.28-1.29).

CONCLUSION

Postmenopausal estrogen replacement therapy may protect against OA of the hip in elderly white women.

Smoking and mortality among older women: the study of osteoporotic fractures

BACKGROUND

Relatively few studies have been focused on the effect of smoking among older individuals. The goal of this study is to investigate the relationship between smoking status and cause-and age-specific mortality among elderly women.

METHODS

Women aged 65 years and older and living in four geographical areas (Baltimore, Md, Minneapolis, Minn, Pittsburgh, Pa, and Portland, Ore) were recruited from various population-based listings for participation in the multicenter Study of Osteoporotic Fractures between September 1986 and October 1988 (N=9704). During a mean follow-up of 4.9 years (<99% complete), 751 deaths occurred. The date and cause of death were ascertained, and the relationship between mortality and current and past smoking status was analyzed using Cox proportional hazards modeling techniques.

RESULTS

Compared with nonsmokers, women smokers aged 65 to 74 years have a more than twofold increase in mortality attributable to increases in both cardiovascular and cancer mortality; death from smoking-related cancers increased eight- to 10-fold. Women 75 years and older who smoke have a small overall increased relative risk (RR) of mortality (RR=1.4; 95% confidence interval [CI], 0.9 to 2.3), but more than five-fold increased risk of dying from a smoking-related cancer (RR=5.2; 95% CI, 1.6 to 16.8). All-cause and cardiovascular death rates approach those of nonsmokers within 10 years after a woman quits smoking; morality from smoking-related cancers remains elevated for at least 23 years.

CONCLUSIONS

The harmful effects of continuing to smoke are apparent even among women aged 75 years and older.

The association of radiographic changes of osteoarthritis of the hand and hip in elderly women

OBJECTIVE

To examine the association of radiographic features of hand and hip osteoarthritis (OA) in elderly women.

METHODS

Hand and hip radiographs were read for changes of OA from a sample of 1422 women aged 65 and above who were participants in the Study of Osteoporotic Fractures. Definite hip OA required the presence of 2 or more of the following: moderate or large osteophytes, moderate or severe joint space narrowing, subchondral sclerosis, cysts, and femoral head deformity. Definite hand OA required moderate or large osteophytes at 2 or more of the following 6 sites: 2nd and 3rd distal and proximal interphalangeal joints and 1st interphalangeal and carpometacarpal joints. Data were analyzed using multiple logistic regression adjusting for age, weight at age 50, and current height.

RESULTS

Overall, 147 (10.4%) women had radiographic changes of definite hip OA and 68 (4.8%) had severe hip OA; 56 had bilateral and 87 had unilateral disease. Definite hand OA was present in 732 (51.4%) women. Hand OA was significantly associated with definite hip OA [odds ratio (OR) = 3.25, 95% confidence intervals (CI) 2.19, 4.84], and severe hip OA (OR = 3.23, 95% CI 1.82, 5.73). Hand OA was significantly associated with bilateral hip OA (OR = 3.54, 95% CI 1.87, 6.73) as well as unilateral hip OA (OR = 3.06, 95% CI 1.84, 5.08).

CONCLUSION

These data are consistent with the inclusion of radiographically defined hip OA in the construct of generalized OA, particularly in elderly women.

Radiographic osteoarthritis of the hip and bone mineral density. The Study of Osteoporotic Fractures Research Group

OBJECTIVE

To examine the cross-sectional association between radiographic features of hip osteoarthritis (OA) and bone mineral density (BMD) of the hip, spine, and appendicular skeleton among Caucasian women ages 65 and older who were participating in the Study of Osteoporotic Fractures.

METHODS

Pelvis radiographs of 4,855 subjects were assessed for individual radiographic features of hip OA: osteophytes, joint space narrowing, subchondral sclerosis, cysts, and femoral head deformity. Hips were graded on a summary scale of 0 (no OA) to 4 (severe OA) based on the number of radiographic features present. Appendicular BMD was measured in all subjects, and hip and spine BMD in 84% of the group. We used linear regression to examine the association of BMD with hip OA, and to adjust for age, weight, and other determinants of bone mass.

RESULTS

Three hundred fifty-one women (7.2%) had mild (grade 2) and 228 (4.7%) had moderate to severe (grade 3-4) radiographic evidence of hip OA. Women with grade 3-4 hip OA had a higher age-adjusted BMD at the femoral neck and Ward's triangle (9-10%; P < 0.0001), trochanter (4%; P < 0.01), lumbar spine (8%; P < 0.0001), and distal radius and calcaneus (5%; P < 0.0001 [for each comparison]) compared with those with grade 0-1 OA in the worse hip. Elevations in BMD were greatest in the femoral neck of hips with OA, in women with bilateral hip OA, and in women with hip osteophytes. These findings were essentially unchanged by adjustment for determinants of bone mass.

CONCLUSION

Elderly Caucasian women with moderate to severe radiographic hip OA had higher BMD in the hip, spine, and appendicular skeleton than did women without hip OA. Our findings are consistent with a role of elevated BMD in the pathogenesis of hip OA.

Gene cloning and complete nucleotide sequence of philippine Schistosoma japonicum paramyosin

The development of an effective vaccine is recognised as a necessary adjunct to the control of schistosomiasis japonica, a disease affecting several million people in China and the Philippines. Currently, recombinant Schistosoma japonicum molecules are considered most suitable for large scale vaccine production and a number of genes encoding vaccine candidate polypeptides have been cloned and expressed (see Waine et al., 1993a). One of the molecules providing most promise as a vaccine target is paramyosin (Butterworth, 1992), a major structural protein of thick filaments in the muscle of most invertebrates; paramyosin genes have now been cloned from a range of parasitic helminths, including schistosomes (Limberger and McReynolds, 1990; Laclette et al., 1991; Dahmen et al., 1993; Landa et al., 1993; Mühlschlegel et al., 1993, Nara et al., 1994). The cloning and nucleotide sequence of S. Japonicum paramyosin is described.

Survey of global telemedicine

The number and scope of telemedicine projects and applications world-wide are growing rapidly along with exponential expansions in national and international information infrastructures and computer capabilities to support them. To track these rapid changes, the Center for Public Service Communications (CPSC) of Arlington, VA, developed the Telemedicine and Information Technologies in Health Care: Project Tracking Document for the National Aeronautics and Space Administration (NASA). This document is maintained by CPSC and frequently updated. It tracks the following areas in telemedicine and health care informatics: (1) major existing Federal grant and other assistance programs and activities; (2) legislation effecting policy in these areas; (3) projects using various technologies throughout the US; and (4) telemedicine projects/interests in other nations. This paper is a survey of international (global) telemedicine activities that are outlined in that document.

Smoking, alcohol, and neuromuscular and physical function of older women. Study of Osteoporotic Fractures Research Group

OBJECTIVE

To determine the associations of current and lifetime smoking and alcohol use with physical function in an older population.

DESIGN

Survey.

SETTING

Four clinic centers in the United States.

PARTICIPANTS

A total of 9704 community-dwelling, ambulatory white women 65 years or older recruited from four areas of the United States.

MAIN OUTCOME MEASURES

Twelve performance tests of muscle strength, agility and coordination, gait and balance, and self-reported functional status.

RESULTS

Compared with women who never smoked, current smokers had significantly poorer function on all of the performance measures except grip strength after adjusting for age, history of stroke, body mass index, clinic site, physical activity, and alcohol use (P < .05). This decrease in function was 50% to 100% as great as that associated with a 5-year increase in age, and most measures worsened with increasing numbers of pack-years. Compared with current moderate drinkers, nondrinkers had significantly poorer function on all of the performance measures except tandem walk (P < .05). Evaluation of a dose effect with alcohol was limited by the small number of heavy drinkers in the study.

CONCLUSIONS

In this population, women who currently smoke are weaker and have poorer balance and poorer performance on measures of integrated physical function than nonsmokers. Smoking is associated with a decline in physical function. Current moderate drinkers have better physical function compared with nondrinkers, but associations of function with heavy drinkers could not be assessed.

Deficient expression of co-stimulatory molecules on Leishmania-infected macrophages

Co-stimulatory signals are necessary for the full activation of T cells for growth and effector function. As co-stimulatory molecules are normally regulated in their expression, it has been suggested that microorganisms enhance their expression on host antigen-presenting cells (APC), thus allowing efficient generation of anti-microbial immunity. We here describe experiments which demonstrate that infection of macrophages, both in vitro and in vivo, by the protozoan parasite Leishmania donovani fails to trigger expression of co-stimulatory molecules B7-1 and heat-stable antigen on these APC. Furthermore, infection with this parasite inhibits the macrophage response to normal regulatory signals, such as bacterial lipopolysaccharide. These changes in the cell surface are mirrored in functional studies of co-stimulation in vitro. Together, these data suggest a further facet of parasite interference in host immunity, but also indicate a potential new target for immunotherapy.

Purification of a recombinant Schistosoma japonicum antigen homologous to the 22-kDa membrane-associated antigen of S. mansoni, a putative vaccine candidate against schistosomiasis

We describe the cDNA cloning, overproduction and purification of a 22.6-kDa antigen from the human blood fluke Schistosoma japonicum. A 777-bp cDNA (C32) was isolated from a S. japonicum lambda ZAPII cDNA expression library immuno-screened with hyperimmune rabbit serum (HRS) raised against soluble adult S. japonicum proteins. The open reading frame of C32 encodes a protein of 191 amino acids (aa) which exhibits 71% identity to a 22.6-kDa membrane-associated antigen of S. mansoni, a putative vaccine candidate for schistosomiasis. We have identified a sequence motif known as an EF-hand calcium-binding domain in both the S. japonicum and S. mansoni aa sequences, suggesting that the 22.6-kDa antigens are able to bind Ca2+. Further, we have, for the first time, obtained the 22.6-kDa antigen in purified, non-denatured, recombinant form, and in sufficient quantity to assess the protective value of the molecule in vaccination/challenge experiments. This was achieved by synthesizing the schistosome antigen with a short polyhistidine tag fused to the N-terminus which was then used for subsequent affinity purification. The recombinant protein was purified under non-denaturing conditions using nickel-chelate affinity chromatography.