User-centered development process of an operating interface to couple a robotic glove with a virtual environment to optimize hand rehabilitation following a stroke.

Introduction: Task-specific neurorehabilitation is crucial to optimize hand recovery shortly after a stroke, but intensive neurorehabilitation remains limited in resource-constrained healthcare systems. This has led to a growing interest in the use of robotic gloves as an adjunct intervention to intensify hand-specific neurorehabilitation. This study aims to develop and assess the usability of an operating interface supporting such a technology coupled with a virtual environment through a user-centered design approach. Methods: Fourteen participants with hand hemiparesis following a stroke were invited to don the robotic glove before browsing through the operating interface and its functionalities, and perform two mobility exercises in a virtual environment. Feedback was collected for improving technology usability. Participants completed the System Usability Scale and ABILHAND questionnaires and their recommendations were gathered and prioritized in a Pugh Matrix. Results: The System Usability Scale (SUS) score for the operating interface was excellent (M = 87.0 SD = 11.6). A total of 74 recommendations to improve the user interface, calibration process, and exercise usability were identified. Conclusion: The application of a full cycle of user-centred design approach confirms the high level of usability of the system which is perceived by end users as acceptable and useful for intensifying neurorehabilitation.

Impact of a checklist used by pharmacists on hospital antimicrobial use: a patient-level interrupted time series study.

BACKGROUND: Antimicrobial misuse leading to drug resistance is a growing concern for clinicians. Improving antimicrobial stewardship programmes through development of new tools could be part of the solution. AIM: To evaluate antimicrobial use in hospitalized patients after implementation of an antimicrobial checklist for ward-based clinical pharmacists. METHODS: A checklist based on quality indicators of optimal antimicrobial use was implemented to standardize hospital pharmacists' assessments of antimicrobial therapy. Antimicrobial use metrics from adults hospitalized during the control and intervention periods were assessed in an interrupted time series analysis of individual patient data. The primary endpoint was days of therapy (DOT) for all antimicrobials per 1000 days present for included patients. Secondary endpoints were the DOT of extended-spectrum antimicrobials (DOT-ES), length of therapy of all antimicrobials (LOT) and the number of pharmacist interventions. FINDINGS: One-thousand six-hundred and nineteen patients were included: 800 and 819 in the pre- and post-checklist implementation periods, respectively. As indicated by the point estimates and their 95% confidence intervals (CIs), there were no changes in trend for DOT, DOT-ES or LOT. A change in level was not found for the DOT, while a change of -118 DOT-ES [-209,-28] and -51 LOT [-97,-4] was documented. Furthermore, pharmacists' interventions regarding antimicrobials increased by 18.7% (14.0, 23.5) and progress notes by 32.3% (27.8, 36.8). CONCLUSION: An antimicrobial checklist used by ward-based clinical pharmacists did not decrease DOT for all antimicrobials, but decreased DOT-ES and LOT upon its implementation.

A Wireless Optoelectronic Neuroscience Platform for Chronic Fluorescence Sensing in Freely Behaving Rodents.

We present a new head mountable wireless fiber biophotometry microsystem conceived to detect fluorescent signal fluctuations correlated with neuronal activity. The proposed system incorporates all aspects of a conventional tethered fiber-based biophotometry system encompassed into a wireless microsystem. The interface includes an LED as excitation light source, a custom designed CMOS biosensor, a multimode fiber, a microcontroller (MCU), and a wireless data transceiver enclosed within a 3D-printed, small and light weight, plastic housing. Precisely, the system incorporates a new optoelectronic biosensor merging two individual building blocks, namely a low-noise sensing front-end and $\mathrm {a}2 ^{nd}$ order continuous-time $\Sigma \Delta $ modulator (CTSDM), into a single module for enabling high-sensitivity and high energy-efficiency photo-sensing. The proposed CMOS biosensor is implemented in $\mathrm {a}0 .18- \mu m$ CMOS technology, consuming $41 \mu W$ from $\mathrm {a}1 .8- V$ supply voltage, while achieving a peak dynamic range of $86 dB$ over a $50- Hz$ input bandwidth at a 20-kS/s sampling rate. This new interface opens new avenues for conducting in-vivo experiments with live animals.

Subgroup effects in a randomised trial of different types and doses of exercise during breast cancer chemotherapy.

BACKGROUND: The Combined Aerobic and Resistance Exercise Trial tested different types and doses of exercise in breast cancer patients receiving chemotherapy. Here, we explore potential moderators of the exercise training responses. METHODS: Breast cancer patients initiating chemotherapy (N=301) were randomly assigned to three times a week, supervised exercise of a standard dose of 25-30 min of aerobic exercise, a higher dose of 50-60 min of aerobic exercise, or a higher dose of 50-60 min of combined aerobic and resistance exercise. Outcomes were patient-reported symptoms and health-related fitness. Moderators were baseline demographic, exercise/fitness, and cancer variables. RESULTS: Body mass index moderated the effects of the exercise interventions on bodily pain (P for interaction=0.038), endocrine symptoms (P for interaction=0.029), taxane/neuropathy symptoms (P for interaction=0.013), aerobic fitness (P for interaction=0.041), muscular strength (P for interaction=0.007), and fat mass (P for interaction=0.005). In general, healthy weight patients responded better to the higher-dose exercise interventions than overweight/obese patients. Menopausal status, age, and baseline fitness moderated the effects on patient-reported symptoms. Premenopausal, younger, and fitter patients achieved greater benefits from the higher-dose exercise interventions. CONCLUSIONS: Healthy weight, fitter, and premenopausal/younger breast cancer patients receiving chemotherapy are more likely to benefit from higher-dose exercise interventions.

Immunologic and structural analysis of eight novel domain-deletion beta3 integrin peptides designed for detection of HPA-1 antibodies.

BACKGROUND: The single-nucleotide polymorphism (SNP) rs5918 in the ITGB3 gene defines the human platelet antigen-1 (HPA-1) system encoding a Leu (HPA-1a) or Pro (HPA-1b) at position 33. HPA-1 antibodies are clinically the most relevant in the Caucasoid population, but detection currently requires alpha(IIb)beta3 integrin from the platelets of HPA-genotyped donors. OBJECTIVES: We set out to define the beta3 integrin domains required for HPA-1a antibody binding and produce recombinant soluble beta3 peptides for HPA-1 antibody detection. METHODS: We designed two sets (1a and 1b) of four soluble beta3 domain-deletion peptides (deltaSDL, deltabetaA, PSIHybrid, PSI), informed by crystallography studies and computer modeling. The footprints of three human HPA-1a-specific phage antibodies were defined by analyzing binding patterns to the beta3 peptides and canine platelets, and models of antibody-antigen interfaces were derived. Specificity and sensitivity for HPA-1a detection were assessed using sera from 140 cases of fetomaternal alloimmune thrombocytopenia (FMAIT). RESULTS: Fusion of recombinant proteins to calmodulin resulted in high-level expression in Drosophila S2 cells of all eight beta3 peptides. Testing of FMAIT samples indicated that deltabetaA-Leu33 is the superior peptide for HPA-1a antibody detection, with 96% sensitivity and 95% specificity. The existence of type I and II categories of HPA-1a antibodies was confirmed by the study of HPA-1a phage antibody footprints and the reactivity pattern of clinical samples with the four beta3-Leu33 peptides, but there was no correlation between antibody category and clinical severity of FMAIT. CONCLUSIONS: Soluble recombinant beta3 peptides can be used for detection of clinical HPA-1a antibodies.

Safe cooling limits from exercise-induced hyperthermia.

We evaluated the cooling rate of hyperthermic subjects, as measured by three estimates of deep core temperatures (esophageal, rectal and aural canal temperatures), during immersion in a range of water temperatures. The objective of the study was to compare the three indices of core temperature and define safe cooling limits when using rectal temperature to avoid the development of hypothermia. On 4 separate days, seven subjects (four males, three females) exercised for 45.4+/-4.1 min at 65% V(O2)max at an ambient temperature of 39 degrees C, RH: 36.5%, until rectal temperature (T (re)) increased to 40.0 degrees C (39.5 degrees C for two subjects). Following exercise, the subjects were immersed in a circulated water bath controlled at 2, 8, 14 and 20 degrees C until T (re) returned to 37.5 degrees C. When T (re) reached normothermia during the cooling period (37.5+/-0.05 degrees C), both esophageal (T (es)) (35.6+/-1.3 degrees C) and aural canal (T (ac)) (35.9+/-0.9 degrees C) temperatures were approaching or reaching hypothermia, particularly during immersion in 2 degrees C water (T (es)=34.5+/-1.2 degrees C). On the basis of the heat loss data, the heat gained during the exercise was fully eliminated after 5.4+/-1.5, 7.9+/-2.9, 10.4+/-3.8 and 13.1+/-2.8 min of immersion in 2, 8, 14 and 20 degrees C water, respectively, with the coldest water showing a significantly faster cooling rate. During the immersion in 2 degrees C water, a decrease of only 1.5 degrees C in T (re) resulted in the elimination of 100% of the heat gained during exercise without causing hypothermia. This study would therefore support cooling the core temperature of hyperthermic subjects to a rectal temperature between 37.8 degrees C (during immersion in water >10 degrees C) and 38.6 degrees C (during immersion in water <10 degrees C) to eliminate the heat gained during exercise without causing hypothermia.

Effect of water temperature on cooling efficiency during hyperthermia in humans.

We evaluated the cooling rate of hyperthermic subjects, as measured by rectal temperature (T(re)), during immersion in a range of water temperatures. On 4 separate days, seven subjects (4 men, 3 women) exercised at 65% maximal oxygen consumption at an ambient temperature of 39 degrees C until T(re) increased to 40 degrees C (45.4 +/- 4.1 min). After exercise, the subjects were immersed in a circulated water bath controlled at 2, 8, 14, or 20 degrees C until T(re) returned to 37.5 degrees C. No difference in cooling rate was observed between the immersions at 8, 14, and 20 degrees C despite the differences in the skin surface-to-water temperature gradient, possibly because of the presence of shivering at 8 and 14 degrees C. Compared with the other conditions, however, the rate of cooling (0.35 +/- 0.14 degrees C/min) was significantly greater during the 2 degrees C water immersion, in which shivering was seldom observed. This rate was almost twice as much as the other conditions (P < 0.05). Our results suggest that 2 degrees C water is the most effective immersion treatment for exercise-induced hyperthermia.

Moderate exercise increases the post exercise resting warm thermoregulatory response thresholds.

BACKGROUND: The purpose of this study was to evaluate the effect of exercise on the subsequent post-exercise core temperature thresholds for vasodilation and sweating. METHODS: On two separate days, with 6 subjects (3 males and 3 females), a whole-body water-perfused suit decreased mean skin temperature until the threshold for vasoconstriction was demonstrated. Mean skin temperature was then slowly increased (approximately 5.0 degrees C x h(-1)) until thresholds for vasodilation and sweating were clearly established. Subjects were cooled by decreasing water temperature until both esophageal and mean skin temperatures returned to near baseline values. Subjects then either performed 15 min of cycle ergometry (60% V(O2max)) followed by 30 min of recovery (Exercise), or remained seated with no exercise for 45 min (Control). Subjects were then cooled again until the onset of cutaneous vasoconstriction followed by a second warming period. The core temperature thresholds for vasodilation and sweating increased significantly by 0.49 degrees C and 0.19 degrees C post-exercise, respectively (p < 0.05). In order to compare thresholds between conditions in which both esophageal and mean skin temperatures were changing, we mathematically compensated for changes in skin temperatures using the established linear cutaneous contribution of skin to the control of vasodilation and sweating (10%). RESULTS: The calculated core temperature threshold (at a designated skin temperature of 36.0 degrees C) for vasodilation increased significantly from 36.56 +/- 0.12 degrees C to 37.11 +/- 0.21 degrees C post-exercise (p < 0.01). Likewise, the sweating threshold increased from 36.79 +/- 0.18 degrees C to 37.05 +/- 0.23 degrees C postexercise (p < 0.01). In contrast, sequential measurements, without exercise, demonstrate a time-dependent decrease (0.18 degrees C) in the sweating threshold, with no difference in the vasodilation threshold. CONCLUSION: These data indicate that exercise has a prolonged effect by increasing the post-exercise thresholds for both warm thermoregulatory responses.

Increasing exercise duration does not affect the postexercise elevation in esophageal temperature.

It has previously been observed that (a) following 15 min of intense exercise, esophageal temperature (Tes) remains elevated at a plateau value equal to that at which active vasodilation had occurred during exercise (i.e., esophageal temperature threshold for cutaneous vasodilation [ThVD]); and (b) exercise/recovery cycles of identical intensity and duration, when sequential, result in progressively higher Tes at the beginning and end of exercise. In the latter case, parallel increases in both the exercise ThVD and postexercise plateau of Tes were noted. This study was conducted to determine if the elevated postexercise Tes is related to increases in whole-body heat content. On separate occasions, 9 subjects completed 3 bouts of treadmill exercise at 70% VO2 max, 29 degrees C ambient temperature. Each exercise bout lasted either 15, 30, or 45 min and was followed by 60 min of inactive recovery. Esophageal temperatures were similar at the start of each exercise bout, but the rise in Tes during exercise nearly doubled from 1.0 degree C after 15 min of exercise to 1.9 degrees C after 45 min of exercise. There were no intercondition differences among the exercise ThVD (approximately 0.36 degree C above baseline) or postexercise plateau values for Tes (approximately 0.40 degree C above baseline). Thus the relationship between the ThVD during exercise and the postexercise Tes did not appear to be dependent on changes in whole-body heat content as produced by endogenous heating during exercise of different duration.

The effect of dynamic exercise on resting cold thermoregulatory responses measured during water immersion.

The purpose of this study was to evaluate the effect of exercise on the subsequent post-exercise thresholds for vasoconstriction and shivering measured during water immersion. On 2 separate days, seven subjects (six males and one female) were immersed in water (37.5 degrees C) that was subsequently cooled at a constant rate of approximately 6.5 degrees C x h(-1) until the thresholds for vasoconstriction and shivering were clearly established. Water temperature was then increased to 37.5 degrees C. Subjects remained immersed for approximately 20 min, after which they exited the water, were towel-dried and sat in room air (22 degrees C) until both esophageal temperature and mean skin temperature (Tsk) returned to near-baseline values. Subjects then either performed 15 min of cycle ergometry (at 65% maximal oxygen consumption) followed by 30 min of recovery (Exercise), or remained seated with no exercise for 45 min (Control). Subjects were then cooled again. The core temperature thresholds for both vasoconstriction and shivering increased significantly by 0.2 degrees C Post-Exercise (P < 0.05). Because the Tsk at the onset of vasoconstriction and shivering was different during Pre- and Post-Exercise Cooling, we compensated mathematically for changes in skin temperatures using the established linear cutaneous contribution of skin to the control of vasoconstriction and shivering (20%). The calculated core temperature threshold (at a designated skin temperature of 32.0 degrees C) for vasoconstriction increased significantly from 37.1 (0.3) degrees C to 37.5 ( 0.3) degrees C post-exercise (P < 0.05). Likewise, the shivering threshold increased from 36.2 (0.3) degrees C to 36.5 (0.3) degrees C post-exercise (P < 0.05). In contrast to the post-exercise increase in cold thermal response thresholds, sequential measurements demonstrated a time-dependent similarity in the Pre- and Post-Control thresholds for vasoconstriction and shivering. These data indicate that exercise has a prolonged effect on the post-exercise thresholds for both cold thermoregulatory responses.

Moderate exercise increases postexercise thresholds for vasoconstriction and shivering.

The purpose of this study was to evaluate the effect of exercise on the subsequent postexercise thresholds for vasoconstriction and shivering. On two separate days, with six subjects (3 women), a whole body water-perfused suit slowly decreased mean skin temperature (approximately 7.0 degreesC/h) until thresholds for vasoconstriction and shivering were clearly established. Subjects were then rewarmed by increasing water temperature until both esophageal and mean skin temperatures returned to near-baseline values. Subjects either performed 15 min of cycle ergometry (65% maximal O2 consumption) followed by 30 min of recovery (Exercise) or remained seated with no exercise for 45 min (Control). Subjects were then cooled again. We mathematically compensated for changes in skin temperatures by using the established linear cutaneous contribution of skin to the control of vasoconstriction and shivering (20%). The calculated core temperature threshold (at a designated skin temperature of 30.0 degreesC) for vasoconstriction increased significantly from 36.64 +/- 0.20 to 36.89 +/- 0.22 degreesC postexercise (P < 0.01). Similarly, the shivering threshold increased from 35.73 +/- 0.13 to 36.13 +/- 0.12 degreesC postexercise (P < 0.01). In contrast, sequential measurements, without exercise, demonstrate a time-dependent decrease in both the vasoconstriction (0.10 degreesC) and shivering (0.12 degreesC) thresholds. These data indicate that exercise has a prolonged effect by increasing the postexercise thresholds for both cold thermoregulatory responses.

Relationship between body image and percent body fat among male and female college students enrolled in an introductory 14-week weight-training course.

Students (39 men and 27 women) from a southern university, who were enrolled in a 14-wk. introductory weight-training course, were administered a 20-item body-image questionnaire and subsequently underwent skinfold measurements to assess percent body fat. Mean scores were correlated with percent body fat. For men, women, and both sexes combined correlations were significant and inverse (rs = -.68, -.41, -.66, respectively). Body image as measured was inversely related to percent body fat among these college students. Researchers should examine how dietary and exercise-induced changes in adiposity (pre-post design) influence scores on body image.

Human monoclonal Fab fragments recovered from a combinatorial library bind specifically to the platelet HPA-1a alloantigen on glycoprotein IIb-IIIa.

BACKGROUND AND OBJECTIVES: Certain clinical conditions are related to the presence of platelet-specific alloantibodies in the patient's serum. We studied the molecular diversity of HPA-1a antibodies to analyze some peculiarities of this antibody response. MATERIALS AND METHODS: Human antibody Fab fragments that bind to the platelet alloantigen HPA-1a on glycoprotein IIb-IIIa (GPIIbIIIa) were generated by using a recombinant phage display system. We established an immunoglobulin G1, kappa combinatorial library from the peripheral blood lymphocytes of a person undergoing a severe posttransfusion purpura. RESULTS: Characterization of Fab clones selected from the fifth round of antigen-specific panning of this library demonstrates a highly specific reactivity to the HPA-1a alloantigen. The nucleotide sequence analysis of representative HPA-la-specific clones reveals at least 3 distinct V1 and 3VH gene segments that present an extensive degree of mutation as demonstrated by comparison of gene usage and homologies to the nearest germline genes. CONCLUSIONS: These human HPA-la-specific Fab reagents should allow us to better understand the molecular mechanism involved in HPA-la alloimmunization.

Presence in peripheral blood of healthy individuals of autoreactive T cells to a membrane antigen present on bone marrow-derived cells.

Intrathymic clonal deletion is thought to be the major mechanism responsible for tolerance to nonsequestered antigens such as the ones expressed by bone marrow-derived cells. In the case of sequestered antigens that potentially do not come in contact with T cells in the thymus, it is thought that autoreactive T cells are present in periphery but are tightly regulated to prevent autoimmune disease. Indeed, autoreactive T cells to sequestered antigens can be isolated in healthy individuals. However, the presence of autoreactive T cells to nonsequestered circulating antigens had not been observed. In this report, we present evidence for the presence, in the periphery of all healthy individuals tested (n = 25), of autoreactive T cells to GpIIb-IIIa, a membrane antigen present on bone marrow-derived cells that is expressed on circulating platelets and on the cell surface of the epithelial cells of the thymic stroma early in intrauterine life. Using an in vitro T-cell proliferation assay, we have demonstrated that activation of these specific GpIIb-IIIa autoreactive alpha beta TCR+ CD4+ CD8- T cells requires internalization and processing of the GpIIb-IIIa by antigen-presenting cells and its presentation by HLA-DR class II molecules in the presence of exogenous interleukin 2 (IL-2). This indicates that some autoreactive T cells directed against membrane antigens present on bone marrow-derived cells and also expressed in the thymus are not necessarily eliminated by intrathymic deletion.

Analysis of immunoglobulin class, IgG subclass and titre of HPA-1a antibodies in alloimmunized mothers giving birth to babies with or without neonatal alloimmune thrombocytopenia.

We analysed the titre and isotype composition of antibodies produced by mothers giving birth to babies with or without neonatal alloimmune thrombocytopenic purpura (NAITP) and patients with post-transfusion purpura (PTP). All these individuals produced an antibody specific for the HPA-1a allotype present on the platelet glycoprotein IIb-IIIa (GPIIb-IIIa). Sera from mothers who gave birth to thrombocytopenic babies (group 1, n = 36), non-thrombocytopenic babies (group 2, n = 4) or from PTP patients (group 3, n = 3) were tested by an indirect-ELISA. Results indicated no evident differences in the isotype composition or titre of the antibodies from the three groups of sera. The antibody titre ranged from 1:120 to 1:3500. Antibodies with the IgG1 subclass were present in all sera. Most sera contained IgG1 alone (24/43 sera tested) or in combination with IgG3 (10/43). IgG2 was never present and only three sera showed intermediate reactivity with anti-IgG4 MAb. Few sera (nine sera from groups 1 and 2) were weakly positive when tested with the anti-IgM antibodies. These results suggest that neither the titre nor the isotype composition can be used to predict the severity or the occurrence of thrombocytopenia in newborns.

Outer membrane proteins P1 and P2 of Haemophilus influenzae type b: structure and identification of surface-exposed epitopes.

The outer membrane proteins (OMPs) P1 and P2 of Haemophilus influenzae type b exhibit molecular size and antigenic variation. Their structural genes have been cloned from prototype isolates of the most common disease-producing clonal groups. The derived amino acid sequences of P1 from strains of OMP subtypes 1H, 3L, and 6U have three variable regions between highly conserved regions. An immunodominant surface-exposed epitope was identified near the carboxyl terminus of P1 proteins from subtype 1H and 3L strains. The P2 genes from subtype 1H, 1L, and 3L isolates were identical. The P2 gene sequence from a subtype 6U isolate differs from the subtype 1H P2 gene by 13 nucleotides, resulting in 10 amino acid changes. The P2 gene from a subtype 2L isolate differs by 1 nucleotide from the subtype 1H P2 gene, resulting in 1 amino acid change at position 166. Two surface-exposed epitopes of OMP P2 were identified, one each between residues 158 and 174 and residues 319 and 341.

Epitope analysis of an immunodominant domain on the P1 protein of Haemophilus influenzae type b using synthetic peptides and anti-idiotypic antibodies.

Synthetic peptides, anti-idiotypic antibodies (anti-Id) and human and murine monoclonal antibodies (mAbs) were used to further define a major antigenic domain on the outer membrane P1 protein (OMP) of Haemophilus influenzae type b (Hib). Synthetic peptides were elaborated from the known primary sequences of the P1 protein of prototype Hib strains MinnA (OMP subtype 1H) and 8358 (OMP subtype 6U). By peptide mapping, antibodies are categorized into three groups: A, B and C. A first epitope on the P1 from strain MinnA was identified by the reactivity of one set of murine anti-P1 mAbs with the two overlapping peptides 11H and 13H, corresponding to amino acid residues 384-412 and 400-437, respectively. On the basis of their reactivity with both peptides, these mAbs were designated as group A. Anti-Id obtained from mice immunized with two group A mAbs reacted specifically with all group A mAbs. A second epitope on the same P1 protein was identified by the reactivity of the peptide 13H with another distinct set of murine anti-P1 mAbs assigned to group B. This group of mAbs did not recognize the peptide 11H. Murine anti-Id which were prepared against one group B mAb inhibited the attachment of this mAb to outer membrane preparations, whereas the binding of the other group B mAbs was not affected, suggesting that these mAbs represent a heterologous group of mAbs. The epitope(s) recognized by two human anti-P1 mAbs was (were) distinct from the ones recognized by murine mAbs since no reactivity with the peptides was observed. Similarly, the binding of the two human mAbs to the P1 antigen was not inhibited by anti-Id raised against group A or B mAbs. Interestingly, an epitope on a different P1 protein recovered from strain 8358 was identified by the reactivity of group C murine mAbs with the peptide 13U, which occupies the same position on the P1 protein as 13H but differs from the latter by 10 amino acid residues. Our studies demonstrated the presence of several distinct surface-exposed B-cell epitopes within the antigenic domain which was defined previously on the P1 protein of Hib MinnA. Furthermore, we showed the immunodominance of this region on two different P1 proteins. None of the mAbs, however, had a bacteriolytic or protective activity against Hib strains. We suggest that the surface-exposed immunodominant region on the OMP P1 of Hib do not induce protective antibodies against Hib infection.

Localization of conserved B-cell epitopes among encapsulated and non-encapsulated Haemophilus influenzae P2 porin proteins using synthetic peptides.

The P2 outer membrane protein of Haemophilus influenzae belongs to a class of apparently ubiquitous proteins in Gram-negative bacteria that function as porins. Murine hybridomas raised to the P2 protein and synthetic peptides were used to investigate the structural and antigenic relationships among P2 proteins of encapsulated and non-encapsulated H. influenzae. Three monoclonal antibodies (mAbs), P2-17, P2-18 and P2-19, recognizing epitopes on the P2 protein, as shown by Western immunoblotting of outer membrane preparations, and purified and recombinant P2 proteins are described. The epitopes reactive with the mAbs were widely distributed among H. influenzae strains since 70-100% of strains of encapsulated and non-encapsulated isolates collected worldwide were recognized by individual mAbs. None of the mAbs reacted with H. parainfluenzae or other bacterial species. The peptide composition of P2 epitopes was determined by analysis of mAb reactivity with a series of overlapping synthetic peptides that covered the amino acid sequences of H. influenzae type b. The domains recognized by these mAbs were completely distinct. mAb P2-18, reactive with an epitope conserved among all H. influenzae P2 porin molecules which were screened, recognized a peptide corresponding to the N-terminal segment (residues 1-14). The P2-17- and P2-19-specific epitopes were located between residues 28 and 55, and 101 and 129, respectively. None of the epitopes were exposed on the cell surface since no mAbs bound to intact live bacteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of a surface-exposed immunodominant epitope on outer membrane protein P1 of Haemophilus influenzae type b.

Eight murine monoclonal antibodies (MAbs) directed against outer membrane protein P1 of Haemophilus influenzae type b were generated and characterized. Seven of the eight MAbs reacted with recombinant P1 and purified P1 protein from H. influenzae type b strains MinnA and 1613; MAb P1.8 was specific for the latter strain. A panel of 32 nontypeable and 140 encapsulated Haemophilus strains recovered worldwide representing the major clonal families of serotypes a, b, and d was used to evaluate the distribution among Haemophilus strains of the epitopes identified by the P1-specific MAbs. The epitope reactive with the seven MAbs which recognized P1 from strains MinnA and 1613 was shared by 92% of the encapsulated Haemophilus isolates tested. The epitope is present in the H. influenzae type b strains from clonal families commonly recovered from cases of invasive disease in North America and Europe. A series of nested 5' and 3' deletions of the P1 gene were constructed and analyzed to localize the determinants on P1 recognized by the MAbs. MAbs P1.2, P1.4, P1.5, P1.6, and P1.7 recognized an epitope localized to the carboxy-terminal portion of P1. Murine MAbs P1.1 and P1.3 and two human MAbs, HiH-7 and HiH-10, recognized a complex epitope which was partially localized to the carboxy-terminal portion of the P1 protein. These data indicate that an immunodominant surface-exposed epitope is present on the carboxy-terminal portion of the P1 protein of type b Haemophilus isolates responsible for the majority of invasive disease in North America.