Electron Signatures of Reconnection in a Global eVlasiator Simulation.

Geospace plasma simulations have progressed toward more realistic descriptions of the solar wind-magnetosphere interaction from magnetohydrodynamic to hybrid ion-kinetic, such as the state-of-the-art Vlasiator model. Despite computational advances, electron scales have been out of reach in a global setting. eVlasiator, a novel Vlasiator submodule, shows for the first time how electromagnetic fields driven by global hybrid-ion kinetics influence electrons, resulting in kinetic signatures. We analyze simulated electron distributions associated with reconnection sites and compare them with Magnetospheric Multiscale (MMS) spacecraft observations. Comparison with MMS shows that key electron features, such as reconnection inflows, heated outflows, flat-top distributions, and bidirectional streaming, are in remarkable agreement. Thus, we show that many reconnection-related features can be reproduced despite strongly truncated electron physics and an ion-scale spatial resolution. Ion-scale dynamics and ion-driven magnetic fields are shown to be significantly responsible for the environment that produces electron dynamics observed by spacecraft in near-Earth plasmas.

Reliability and construct validity of the modified Finnish version of the 9-item patient health questionnaire and its associations within the biopsychosocial framework among female health-care workers with sub-acute or recurrent low back pain.

BACKGROUND: Health-care workers have an increased risk for chronic low back pain (LBP) leading to reduced workability. Depression, a highly prevalent, costly and disabling condition, is commonly seen in patients with sub-acute LBP. This study investigated the psychometric properties and construct-validity of a modified 9-item Patient Health Questionnaire (PHQ-9-mFIN) in female health-care workers with sub-acute LBP. METHODS: Reliability (internal consistency, test-retest repeatability) was assessed using standard methods. Construct validity of the PHQ-9-mFIN was assessed as level of depressive symptoms (PHQ-9-mFIN: 0-4 none, 5-9 mild, ≥10 at least moderate) against the RAND 36 Health Survey, a valid measure of health-related quality of life (HRQoL). Additionally, the strength of the association between the levels of PHQ-9-mFIN and selected biopsychosocial factors was determined. RESULTS: The internal consistency of the PHQ-9-mFIN was high (Cronbach's α = 0.82) and the test-retest repeatability scores (n = 64) were moderate: Pearson's correlation was 0.73 and Intraclass Correlation Coefficient (ICC) 0.73 (95% CI: 0.58 to 0.82). Construct validity (Spearman correlation) against the Physical and Mental component items and their summary scales of the RAND 36 were much higher for the Mental (range, - 0.40 to - 0.67 and - 0.64) than for the Physical (range, - 0.08 to - 0.43 and - 0.22). There was a clear stepwise association (p < 0.001) between the levels of depressive symptoms and General health (physical component, range, 59.1 to 78.8). The associations with all items of the Mental components were strong and graded (p < 0.001). All participants had low scores for Bodily pain, regardless of the level of depressive symptoms. There was a strong association (p ≤ 0.003) between the levels of PHQ-9-mFIN and multisite pain, lumbar exertion and recovery after workdays, neuromuscular fitness in modified push-ups, workability, and fear of pain related to work. CONCLUSIONS: The PHQ-9-mFIN showed adequate reliability and excellent construct validity among female health-care workers with recurrent LBP and physically strenuous work. TRIAL REGISTRATION: NCT01465698 .

Reliable recognition of lying, sitting, and standing with a hip-worn accelerometer.

Hip-worn accelerometers are widely used to estimate physical activity (PA), but the accuracy of acceleration threshold-based analysis is compromised when it comes to identifying stationary and sedentary behaviors, let alone classifying body postures into lying, sitting, or standing. The purpose of this study was to devise a novel method for accurate classification of body posture using triaxial data from hip-worn accelerometer and to evaluate its performance in free-living conditions against a thigh-worn accelerometer. The posture classification rested on 2 facts: constant Earth's gravity vector and upright walking posture. Thirty healthy adults wore a hip-mounted accelerometer and underwent an array of lying, sitting, standing, and walking tasks. Task type, their order, and length were randomly assigned to each participant. During walking, the accelerometer orientation in terms of gravity vector was taken as reference, and the angle for posture estimation (APE) was determined from the incident accelerometer orientation in relation to the reference vector. Receiver operating characteristic (ROC) curve yielded an optimal cut-point APE of 64.9° (sensitivity 100% and specificity 100%) for lying and sitting and 11.6° (94.2%; 94.5%) for sitting and standing. In free-living conditions, high agreement (89.2% for original results and 90.4% for median-filtered results) in identifying sedentary periods (sitting and lying) was observed between the results from hip- and thigh-worn accelerometers. Walking provides a valid reference activity to determine the body posture. The proposed APE analysis of the raw data from hip-worn triaxial accelerometer gives accurate and specific information about daily times spent lying, sitting, and standing.

Self-reported health-enhancing physical activity recommendation adherence among 64,380 finnish adults.

The Finnish recommendations for health-enhancing physical activity (PA) for adults (≥18 years) recommend: (i) ≥150 minutes of moderate-to-vigorous-intensity physical activity (MVPA) and (ii) activities that develop muscle strength and balance ≥2 days/week. However, adherence to these recommendations among the Finnish adults is currently unknown. This study reports on the self-reported adherence to the PA recommendations and associations with sociodemographic factors among Finnish adults. Data were used from the Finnish "Regional Health and Well-being Study." In 2013-2014, postal questionnaires were sent to 132,560 persons, with 69,032 responding (response rate =52.1%). The weighted proportions adhering to the: (i) MVPA recommendation, (ii) sufficient muscle-strengthening activity (≥2 days/week), (iii) sufficient balance training (≥2 days/week), and (iv) Finnish health-enhancing PA recommendations (Finnish recommendations) were calculated. Associations with sociodemographic variables (eg, age, education level, self-rated health) were assessed using multiple logistic regression analyses. Of 69,032 respondents, 92.6% (n=64,380, response rate =48.6%, 18-98 years) reported on their physical activity levels. A total of 31.2% (95% CI: 30.8%-31.6%) met the aerobic MVPA recommendation, 17.2% (95% CI: 16.9%-17.6%) reported sufficient muscle-strengthening activity, 6.7% (95% CI: 6.4%-6.9%) reported sufficient balance training, and 10.8% (95% CI: 10.5%-11.1%) met the Finnish recommendations. In the adjusted analysis, those with poorer self-rated health, older age, lower education levels, and those classified overweight or obese were independently associated with lower odds of meeting the Finnish recommendations. The vast majority of Finnish adults do not meet the full PA recommendations. Public health action is needed to increase PA in Finland.

Primary care-based facial pain unit in Vantaa: the first experiences 2003­2009.

As an attempt to tackle the challenge in serving facial pain patients, the first primary care-based facial pain unit was founded in 2003 as part of public dental primary care of Vantaa, Finland. Data were collected, consisting of sex, age, sources of referrals, reasons for seeking care, diagnoses made, therapeutic procedures, and numbers of visits to dentists and phone consultations. To describe the development of the present pain management system, we divided the observation periods into two parts: 2003-2006 and 2007-2009 and compared frequencies of the studied parameters between the two follow-up periods. During 2003-2006, 370 patients were examined and the number of visits was 659, corresponding patients' number was 437 and visits' number 960 during 2007-2009. Referrals to the primary care facial pain unit came from primary care dentists (80%), respective primary care pain unit GPs (6%), oral hygienists (3%) and ordinary GPs (2%). Four percentage of the patients' referrals came from secondary and tertiary care clinics of various types and 5% from private sector dentists and specialists. The average number of telephone consultations per year increased from 51 to 300 between study periods. During the follow-up period, the main reason for seeking care from our unit was temporomandibular disorders. Education in self-care, oral appliance therapy and physiotherapy were mostly used as management for these pain problems. The facial pain management unit in primary health care could be a useful model to serve increasing numbers of chronic facial pain patients.

Review of 36,537 patient records for tooth health and longevity of dental restorations.

To develop an automatic system for utilizing electronic dental records, a data mining system to extract the diagnostic and treatment codes from the records for an intermediate file and automatic drawing of Kaplan-Meier-type survival curves was first created. Then this intermediate file was analyzed with SAS software for the scientific determination of Kaplan-Meier survival of tooth/surface-specific healthy time and survival of restorations in each permanent tooth, health center, and age cohort and also combined. All patients born in 1985, 1990 or 1995 in 28 health centers in Finland were analyzed. Patients classified as caries-active were those who had caries in any first permanent molar under the age of 8 years, while resistant patients did not have caries in these teeth before 10 years. In the younger age cohorts, a shortening of survival of caries-free teeth was seen. The shortest caries-free survival was seen in mandibular and maxillary molars in the youngest age cohort. Occlusal surfaces of molars determined their caries onsets and proximal caries occurred equally in molars, incisors and premolars, whereas canines or mandibular incisors did not have caries in these age cohorts. Caries-prone subjects had the shortest survival in all their teeth. The median longevity of all restorations was 11.7 years, with great variation between health centers and teeth. Because of the great variation between individual teeth, the tooth-specific approach seems appropriate in both caries epidemiology and material sciences.

Acceptance of oral health promotion programmes by dental hygienists and dental nurses in public dental service.

OBJECTIVES: The aim of this study was to analyse how dental hygienists and in-service trained dental nurses accepted new health promotion programmes, how did they experience them in practice, and how did these programmes affect their attitudes to work. METHODS: The subjects were all the dental hygienists and in-service trained dental nurses (n = 28) involved in health promotion of small children. Education and written instructions on two new programmes had been given to the professionals in two areas of Vantaa and those in the third area used the routine programme. The transtheoretical model (TTM) was selected as the theoretical framework for counselling. A structured questionnaire of 31-35 items was sent to all subjects. Independent samples Mann-Whitney U and Fisher's exact tests were used as statistical methods. RESULTS: The response rate was 89%. All respondents felt that the work they had carried out had always been important during their working career. Twenty-one of 25 respondents reported that the instructions and education were suitable for oral health promotion. The respondents within the new programmes felt they had advanced more as health professionals (P = 0.020) and acquired more confidence from the education (P = 0.018) compared with the routine programme. CONCLUSIONS: The new programmes for small children were well accepted by the dental hygienists and the in-service trained dental nurses, and the majority of them gained some new practices for their work.

Reliability of field-based fitness tests in youth.

The objective of this systematic review was to study the reliability of the existing field-based fitness tests intended for use with children and adolescents. The medical electronic databases MEDLINE, SCOPUS and SPORTS DISCUS were screened for papers published from January 1990 to December 2009. Each study was classified as high, low or very low quality according to the description of the participants, the time interval between measurements, the description of the results and the appropriateness of statistics. 3 levels of evidence were constructed according to the number of studies and the consistency of the findings. 32 studies were finally included in the present review. The reliability of tests assessing cardiorespiratory fitness (9 studies), musculoskeletal fitness (12 studies), motor fitness (3 studies), and body composition (10 studies) was investigated. Although some fitness components warrant further investigation, this review provides an evidence-based proposal for most reliable field-based fitness tests for use with children and adolescents: 20-m shuttle run test to measure cardiorespiratory fitness; handgrip strength and standing broad jump tests to measure musculoskeletal fitness; 4×10 m shuttle run test for motor fitness; and height, weight, BMI, skinfolds, circumferences and percentage body fat estimated from skinfold thickness to measure body composition.

Criterion-related validity of field-based fitness tests in youth: a systematic review.

The objective of this systematic review was to comprehensively study the criterion-related validity of the existing field-based fitness tests used in children and adolescents. The studies were scored according to the number of subjects, description of the study population and statistical analysis. Each study was classified as high, low and very low quality. Three levels of evidence were constructed: strong evidence, when consistent findings were observed in three or more high quality studies; moderate evidence, when consistent findings were observed in two high quality studies; and limited evidence when consistency of findings and/or the number of studies did not achieve the criteria for moderate. The results of 73 studies (50 of high quality) addressing the criterion-related validity of field-based fitness tests in children and adolescents indicate the following: that there is strong evidence indicating that the 20 m shuttle run test is a valid test to estimate cardiorespiratory fitness, that the hand-grip strength test is a valid measure of musculoskeletal fitness, that skin fold thickness and body mass index are good estimates of body composition, and that waist circumference is a valid measure to estimate central body fat. Moderate evidence was found that the 1-mile run/walk test is a valid test to estimate cardiorespiratory fitness. A large number of other field-based fitness tests presented limited evidence, mainly due to a limited number of studies (one for each test). The results of the present systematic review should be interpreted with caution due to the substantial lack of consistency in reporting and designing the existing validity studies.

A practice-based study of the variation of diagnostics of dental caries in new and old patients of different ages.

Data mining of digital dental records provides possibilities for analysing the variation between dentists when diagnosing caries. A total of 71,317 male and 82,302 female subjects visited the health centres in Vantaa and Kemi during the 'digital era' (1994-2005). As subjects were classified as 'new patients' at the first examination, all re-examinations of the same subjects thereafter by the same dentist produced 'old patients'. A mean number of decayed surfaces (DS) was counted as a function of the age of the subject during the follow-up. The significance of the difference between old and new patients was determined by the Mann-Whitney test for each age cohort at the cross sections, and for the whole follow-up. Caries was seen to affect new patients more than the old ones in both health centres after the age of 20 years. The mean DS values were the same, reaching about 1 for new and old patients at the age of 15 years. The mean DS had a peak for new patients in both health centres at the age of 25 years and another peak around 45-50 years in Kemi. With a few exceptions there was a significant difference between the DS values of new and old patients at most cross sections and for the whole follow-up time. Evidently dentists examine new patients more carefully than their old patients. After the age of 18 years patients may have changed their dentists because they have finished the free-of-charge treatment period.

Predictive validity of health-related fitness in youth: a systematic review.

The objective of the present systematic review was to investigate whether physical fitness in childhood and adolescence is a predictor of cardiovascular disease (CVD) risk factors, events and syndromes, quality of life and low back pain later in life. Physical fitness-related components were: cardiorespiratory fitness, musculoskeletal fitness, motor fitness and body composition. Adiposity was considered as both exposure and outcome. The results of 42 studies reporting the predictive validity of health-related physical fitness for CVD risk factors, events and syndromes as well as the results of five studies reporting the predictive validity of physical fitness for low back pain in children and adolescents were summarised. Strong evidence was found indicating that higher levels of cardiorespiratory fitness in childhood and adolescence are associated with a healthier cardiovascular profile later in life. Muscular strength improvements from childhood to adolescence are negatively associated with changes in overall adiposity. A healthier body composition in childhood and adolescence is associated with a healthier cardiovascular profile later in life and with a lower risk of death. The evidence was moderate for the association between changes in cardiorespiratory fitness and CVD risk factors, and between cardiorespiratory fitness and the risk of developing the metabolic syndrome and arterial stiffness. Moderate evidence on the lack of a relationship between body composition and low back pain was found. Due to a limited number of studies, inconclusive evidence emerged for a relationship between muscular strength or motor fitness and CVD risk factors, and between flexibility and low back pain.

Efficacy of six months neuromuscular exercise on lumbar movement variability - A randomized controlled trial.

INTRODUCTION: Lumbar movement variability during heavy, repetitive work may be a protective mechanism to diminish the progression of lumbar disorders and maintain neuromuscular functional integrity. The effect of neuromuscular exercise (NME) on the variability of lumbar movement is still to be determined. METHODS: A randomised controlled trial was conducted on a population of nursing personnel with subacute LBP. Following randomization, the NME group participants completed an NME program of six months duration. The participants in the control group only attended the assessment sessions. The outcomes were assessed at: baseline; after six months intervention; 12 months. The primary outcome was lumbar movement variability based on angular displacement and velocity. RESULTS: A positive treatment effect on lumbar movement variability was seen after six months of NME intervention. Angular displacement improved, and angular velocity remained constant. At the 12-month follow up, however, the effect faded in the NME group. Lumbar movement variability worsened in the control group over all time periods. CONCLUSION: NME may improve lumbar movement variability in the short term and may indicate improved neuromuscular functional integrity. The design of an optimal NME program to achieve long-term improvement in lumbar movement variability is a subject worthy of further research.

The effect of muscle fatigue and low back pain on lumbar movement variability and complexity.

INTRODUCTION: Changes in movement variability and complexity may reflect an adaptation strategy to fatigue. One unresolved question is whether this adaptation is hampered by the presence of low back pain (LBP). This study investigated if changes in movement variability and complexity after fatigue are influenced by the presence of LBP. It is hypothesised that pain free people and people suffering from LBP differ in their response to fatigue. METHODS: The effect of an isometric endurance test on lumbar movement was tested in 27 pain free participants and 59 participants suffering from LBP. Movement variability and complexity were quantified with %determinism and sample entropy of lumbar angular displacement and velocity. Generalized linear models were fitted for each outcome. Bayesian estimation of the group-fatigue effect with 95% highest posterior density intervals (95%HPDI) was performed. RESULTS: After fatiguing %determinism decreased and sample entropy increased in the pain free group, compared to the LBP group. The corresponding group-fatigue effects were 3.7 (95%HPDI: 2.3-7.1) and -1.4 (95%HPDI: -2.7 to -0.1). These effects manifested in angular velocity, but not in angular displacement. DISCUSSION: The effects indicate that pain free participants showed more complex and less predictable lumbar movement with a lower degree of structure in its variability following fatigue while participants suffering from LBP did not. This may be physiological responses to avoid overload of fatigued tissue, increase endurance, or a consequence of reduced movement control caused by fatigue.

Immunosuppression in homosexual men seronegative for HTLV-III.

Clinical, microbiological, and lifestyle patterns in homosexual men showing in vitro immunological abnormalities were studied and related to the susceptibility to human T-lymphotropic virus type III (HTLV-III) infection. In a cohort of male homosexual volunteers in Finland, 90% were HTLV-III antibody negative. Ten % of the HTLV-III negative cases showed decreased T-helper/suppressor cell ratios, mostly due to elevated numbers of T-suppressor cells. In this immunosuppressed group, more signs of diarrhea, intestinal giardiasis, genital warts, and hepatitis B were observed than in the other HTLV-III antibody-negative study subjects. The type of sexual practice was not associated with the in vitro immune abnormalities. During a follow-up of up to 16 months, 4 initially HTLV-III antibody negative cases showed seroconversion. Three of these had inverted T-helper/suppressor cell ratios prior to the seroconversion. It is concluded that persons showing in vitro immunosuppression are more susceptible to HTLV-III infection when being exposed to the virus or else alteration in T-cell subsets signals a pre-antibody-positive or early phase of HTLV-III infection.

Pain intensity attenuates movement control of the lumbar spine in low back pain.

INTRODUCTION: Pain intensity attenuates muscular activity, proprioception, and tactile acuity, with consequent changes of joint kinematics. People suffering from low back pain (LBP) frequently show movement control impairments of the lumbar spine in sagittal plane. This cross-sectional, observational study investigated if the intensity of LBP attenuates lumbar movement control. The hypothesis was that lumbar movement control becomes more limited with increased pain intensity. METHODS: The effect of LBP intensity, measured with a numeric rating scale (NRS), on lumbar movement control was tested using three movement control tests. The lumbar range of motion (ROM), the ratio of lumbar and hip ROM as indicators of direction specific movement control, and the recurrence and determinism of repetitive lumbar movement patterns were assessed in ninety-four persons suffering from LBP of different intensity and measured with an inertial measurement unit system. Generalized linear models were fitted for each outcome. RESULTS: Lumbar ROM (+ 0.03°, p = 0.24) and ratio of lumbar and hip ROM (0.01, p = 0.84) were unaffected by LBP intensity. Each one point increase on the NRS resulted in a decrease of recurrence and determinism of lumbar movement patterns (-3.11 to -0.06, p ⩽ 0.05). DISCUSSION: Our results indicate changes in movement control in people suffering from LBP. Whether decreased recurrence and determinism of lumbar movement patterns are intensifiers of LBP intensity or a consequence thereof should be addressed in a future prospective study.

Concurrent validity and reliability of a novel wireless inertial measurement system to assess trunk movement.

INTRODUCTION: Assessment of movement dysfunctions commonly comprises trunk range of motion (ROM), movement or control impairment (MCI), repetitive movements (RM), and reposition error (RE). Inertial measurement unit (IMU)-systems could be used to quantify these movement dysfunctions in clinical settings. The aim of this study was to evaluate a novel IMU-system when assessing movement dysfunctions in terms of concurrent validity and reliability. METHODS: The concurrent validity of the IMU-system was tested against an optoelectronic system with 22 participants. The reliability of 14 movement dysfunction tests were analysed using generalizability theory and coefficient of variation, measuring 24 participants in seven trials on two days. RESULTS: The IMU-system provided valid estimates of trunk movement in the primary movement direction when compared to the optoelectronic system. Reliability varied across tests and variables. On average, ROM and RM were more reliable, compared to MCI and RE tests. DISCUSSION: When compared to the optoelectronic system, the IMU-system is valid for estimates of trunk movement in the primary movement direction. Four ROM, two MCI, one RM, and one RE test were identified as reliable and should be studied further for inter-subject comparisons and monitoring changes after an intervention.

Highly immunoreactive antigenic site in a hydrophobic domain of HIV-1 gp41 which remains undetectable with conventional immunochemical methods.

A synthetic pentadecapeptide (A15; env residues 599-613: SGKLICTTAVPWNAS), derived from a hydrophobic region in the transmembrane protein gp41 of HIV-1 and comprising a highly immunoreactive antigenic site in eliciting antibody responses during HIV-1 infection in humans, was used to purify, by affinity, the corresponding anti-peptide antibodies from HIV-1-infected patient sera. The purified antibodies to peptide A15 reacted specifically with the peptide in EIA, but not in whole virus EIA. These antibodies were immunoreactive with the corresponding peptide-albumin conjugates in immunoblotting but not with gp41 molecules. The results suggest that the peptide A15 sequence is not exposed in intact gp41, but will be exposed and is antigenic in the course of HIV-1 infection in humans.

Identification of antigenic components of Toxoplasma gondii by an immunoblotting technique.

Proteins of Toxoplasma gondii were separated by SDS-polyacrylamide gel electrophoresis with subsequent transfer to a nitrocellulose sheet by electrophoretic blotting. Immunologically reactive polypeptides were detected by human sera with previously known toxoplasma antibody levels. Heavy chain-specific, peroxidase-conjugated anti-human immunoglobulins were used as the indicator antibodies for the separate identification of IgG and IgM reactive polypeptides. IgG toxoplasma antibodies reacted with several antigens of Mr approximately 27 000-67 000, while toxoplasma-specific IgM seemed to detect only a few polypeptides. The Mr of 35 000 for the dominating IgM reactive polypeptide was observed.

Zidovudine reduces intrathecal immunoactivation in patients with early human immunodeficiency virus type 1 infection.

OBJECTIVE: To evaluate the effect of zidovudine on human immunodeficiency virus type 1 (HIV-1)-associated central nervous system infection in Centers for Disease Control and Prevention stage II or III disease. DESIGN: In an open-ended trial, patients received 500 mg of zidovudine twice a day for 12 months. Lumbar punctures, neurological, neuropsychological, and neuroradiological examinations were repeatedly performed during the trial period and were compared with pretrial values. In 11 patients post-trial neurological follow-up of 10 to 20 months was performed. PATIENTS: Initially, 14 volunteers with stage II or III disease and intrathecal synthesis of HIV-1-specific antibodies were enrolled. Additionally, patients had slight neuropsychological disturbance or brain atrophy unrelated to other agents than HIV-1. Two patients dropped out because of poor compliance. MAIN OUTCOME MEASURES: Intrathecal and systemic immune and virological responses, cognitive performance, and brain images were repeatedly monitored. RESULTS: After 6 weeks of zidovudine therapy, initial low-grade pleocytosis and elevated levels of beta 2-microglobulin, both in cerebrospinal fluid and in serum samples, declined. Intrathecal HIV-1 antibody synthesis could no longer be detected in half of the patients after 12 months of zidovudine therapy. Patients with defective cognition transiently improved cognitive speed and flexibility after 6 months of therapy. Slight atrophic brain changes, however, remained unchanged. CONCLUSIONS: Zidovudine reduces intrathecal immuno-activation and transiently improves cognitive functioning in HIV-1-infected subjects who show evidence of central nervous system involvement by HIV-1 but are otherwise asymptomatic.

Intrathecal humoral immunologic response in neurologically symptomatic and asymptomatic patients with human immunodeficiency virus infection.

We analyzed the intrathecal humoral immunologic response in 42 human immunodeficiency virus (HIV)-infected patients. Eighteen patients had clinical neurologic abnormalities, while the remaining 24 patients were neurologically symptom-free. Nine of the neurologically symptomatic patients at early infection had slight neurologic dysfunction; in nine other subjects at late infection, the neurologic impairment was moderate or severe. When compared with symptom-free patients, neurologically symptomatic patients had increased intra-blood-brain barrier (BBB) HIV-specific IgG (p less than 0.001) and total IgG synthesis (p less than 0.01) with oligoclonal bands (OCBs) in the CSF and/or serum (11/18 versus 3/24). At early stages of the infection, neurologically symptomatic patients showed increased total intrathecal IgG synthesis (9/9) coincident with OCBs in the CSF and serum (7/9) and slight mononuclear pleocytosis (7/9), but less frequent HIV-specific IgG production within the CNS (6/9). In advanced infection, the number of neurologically symptomatic patients with intrathecal HIV-specific IgG synthesis (8/9) was higher, while the number of those with increased total intra-BBB IgG synthesis (5/9; p less than 0.01), OCBs (4/9), and increased CSF leukocyte count (1/9; p less than 0.001) was lower than at early infection. Our data suggest humoral intra-BBB immunoactivation at early stages of HIV infection followed by declining B cell response within the CNS at advanced infection.