International standards to document remaining autonomic function after spinal cord injury

This is the first guideline describing the International Standards to document remaining Autonomic Function after Spinal Cord Injury (ISAFSCI). This guideline should be used as an adjunct to the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) including the ASIA Impairment Scale (AIS), which documents the neurological examination of individuals with SCI. The Autonomic Standards Assessment Form is recommended to be completed during the evaluation of individuals with SCI, but is not a part of the ISNCSCI. A web-based training course (Autonomic Standards Training E Program (ASTeP)) is available to assist clinicians with understanding autonomic dysfunctions following SCI and with completion of the Autonomic Standards Assessment Form (www.ASIAlearningcenter.com).

Identification of enolases and aldolases as important fish allergens in cod, salmon and tuna: component resolved diagnosis using parvalbumin and the new allergens

BACKGROUND

The majority of fish-allergic patients are sensitized to parvalbumin, known to be the cause of important IgE cross-reactivity among fish species. Little is known about the importance of fish allergens other than parvalbumin.

OBJECTIVE

The aim of this study was to characterize hitherto undefined fish allergens in three commonly consumed fish species, cod, salmon and tuna, and to evaluate their importance for in vitro IgE-diagnosis in addition to parvalbumin and fish gelatin.

METHODS

Sixty-two patients were diagnosed by clinical history, skin prick tests and specific IgE to fish extracts. Two new fish allergens from cod, salmon and tuna were identified by microsequencing. These proteins were characterized by immunoblot, ELISA and mediator release assay. Purified parvalbumin, enolase, aldolase and fish gelatin were used for quantification of specific IgE in ELISA.

RESULTS

Parvalbumin and two other allergens of 50 and 40 kDa were detected in IgE-immunoblots of cod, salmon and tuna extracts by most patient sera. The 50 and 40 kDa proteins were identified as beta-enolase and fructose-bisphosphate aldolase A respectively. Both purified enzymes showed allergenic activity in the mediator release assay. Indeed, 72.6% of the patients were sensitized to parvalbumin, 20% of these had specific IgE to salmon parvalbumin only. IgE to enolases were found in 62.9% (0.5-95.0 kUA /L), to aldolases in 50.0% (0.4-26.0 kUA /L) and to fish gelatin in 19.3% (0.4-20.0 kUA /L) of the patients. Inter-species cross-reactivity, even though limited, was found for enolases and aldolases by IgE-inhibition ELISA.

CONCLUSIONS AND CLINICAL RELEVANCE

Fish enolase and aldolase have been identified as important new fish allergens. In fish allergy diagnosis, IgE to enolase and aldolase are especially relevant when IgE to parvalbumin are absent.

Development of a functional in vitro assay as a novel tool for the standardization of allergen extracts in the human system

BACKGROUND

Biochemical and immunochemical methods used for batch control of allergen extracts rely on the binding of IgE molecules to allergens. They do not measure the ability of a protein to induce type I allergic reactions. Therefore, a biological assay was established that is based on the cellular mechanisms of allergies in order to assess the cross-linking capacity of allergens.

METHODS

Rat basophilic leukaemia cells were transfected with cDNA coding for the human high affinity IgE receptor chains. The surface expression of the IgE-binding alpha-chain was detected by FACS analysis and the functional integration of the 'humanized' receptors into the signal transduction cascade was addressed by intracellular calcium mobilization. Mediator release was measured in response to human IgE and a variety of cross-linking allergen preparations.

RESULTS

Several clones were obtained that were able to bind allergen-specific human IgE. The results of the biological assay were compared with those obtained by immunochemical methods. The biological assay was used to determine the potency of allergen extracts, including highly diluted products that cannot be analysed by conventional methods.

CONCLUSION

A stable 'humanized' basophil cell line was established that will be a useful tool for the standardization and batch control of allergen extracts. Because of its high sensitivity, it can also be used to detect minute quantities of potentially allergenic proteins, e.g. in processed foods. In addition, the test may support the development of novel allergy vaccines, such as recombinant hypoallergenic molecules.

IgE recognition patterns in peanut allergy are age dependent: perspectives of the EuroPrevall study

BACKGROUND

We tested the hypothesis that specific molecular sensitization patterns correlate with the clinical data/manifestation in a European peanut-allergic population characterized under a common protocol.

METHODS

Sixty-eight peanut-allergic subjects and 82 tolerant controls from 11 European countries were included. Allergy to peanut and lowest symptom-eliciting dose was established by double-blind placebo-controlled food challenge in all but anaphylactic subjects. Information of early or late (before or after 14 years of age) onset of peanut allergy was obtained from standardized questionnaires. IgE to peanut allergens rAra h 1-3, 6, 8-9, profilin and CCD was determined using ImmunoCAP.

RESULTS

Seventy-eight percent of peanut allergics were sensitized to peanut extract and 90% to at least one peanut component. rAra h 2 was the sole major allergen for the peanut-allergic population. Geographical differences were observed for rAra h 8 and rAra h 9, which were major allergens for central/western and southern Europeans, respectively. Sensitization to rAra h 1 and 2 was exclusively observed in early-onset peanut allergy. Peanut-tolerant subjects were frequently sensitized to rAra h 8 or 9 but not to storage proteins. Sensitization to Ara h 2 ≥ 1.0 kUA /l conferred a 97% probability for a systemic reaction (P = 0.0002). Logistic regression revealed a significant influence of peanut extract sensitization and region on the occurrence of systemic reactions (P = 0.0185 and P = 0.0436, respectively).

CONCLUSION

Sensitization to Ara h 1, 2 and 3 is usually acquired in childhood. IgE to Ara h 2 ≥ 1.0 kUA /l is significantly associated with the development of systemic reactions to peanut.

Nitration Enhances the Allergenic Potential of Proteins

BACKGROUND

Recent investigations have shown that proteins, including Bet v 1a, are nitrated by exposure to polluted urban air. We have investigated immunogenic and allergenic properties of in vitro nitrated allergens in in vivo models.

METHODS

Untreated and nitrated samples of ovalbumin or Bet v 1a were compared for their ability to stimulate proliferation and cytokine secretion in splenocytes from DO11.10 or from sensitized BALB/c mice, and for their ability to induce specific immunoglobulin (Ig)G1, IgG2a and IgE in sensitized mice. Additionally, sera from birch pollen-allergic individuals were analysed for IgE and IgG specific for nitrated Bet v 1a.

RESULTS

Upon splenocyte stimulation with nitrated as compared with unmodified allergens, proliferation as well as interleukin 5 and interferon-gamma production were enhanced. Sera of mice sensitized with nitrated allergens showed elevated levels of specific IgE, IgG1 and IgG2a, compared with sera from mice sensitized with unmodified allergens. Moreover, cross-reactivity of antibodies against unrelated, nitrated allergens was observed in mice. We also found higher amounts of functional, specific IgE against nitrated than against untreated Bet v 1a in sera from birch pollen-allergic patients.

CONCLUSIONS

Our findings suggest that nitration enhances allergic responses, which may contribute to an increased prevalence of allergic diseases in polluted urban environments.

Recommendations for translation and reliability testing of International Spinal Cord Injury Data Sets

OBJECTIVE

To provide recommendations regarding translation and reliability testing of International Spinal Cord Injury (SCI) Data Sets.

SETTING

The Executive Committee for the International SCI Standards and Data Sets.

RECOMMENDATIONS

Translations of any specific International SCI Data Set can be accomplished by translation from the English version into the target language, and be followed by a back-translation into English, to confirm that the original meaning has been preserved. Another approach is to have the initial translation performed by translators who have knowledge of SCI, and afterwards controlled by other person(s) with the same kind of knowledge. The translation process includes both language translation and cultural adaptation, and therefore shall not be made word for word, but will strive to include conceptual equivalence. At a minimum, the inter-rater reliability should be tested by no less than two independent observers, and preferably in multiple countries. Translations must include information on the name, role and background of everyone involved in the translation process, and shall be dated and noted with a version number.

CONCLUSION

By following the proposed guidelines, translated data sets should assure comparability of data acquisition across countries and cultures. If the translation process identifies irregularities or misrepresentation in either the original English version or the target language, the working group for the particular International SCI Data Set shall revise the data set accordingly, which may include re-wording of the original English version in order to accomplish a compromise in the content of the data set.

Mediator release assays based on human or murine immunoglobulin E in allergen standardization

BACKGROUND

The biological potency of allergens can be measured by provoking mediator release from effector cells. As established immunochemical methods in allergen standardization only determine inhibition potency or major allergen content, routine tests for biological potency may enhance standardization and batch control of allergen products.

OBJECTIVE

The general performance and application potential of biological in vitro assays in batch control and standardization of allergens and as a tool for verifying activity and stability of allergen standards were analysed.

METHODS

Allergen extracts of five clinically relevant allergens from three to five different manufacturers were investigated. A CAP-IgE-inhibition assay was compared with mediator release assay (MRA)s based on murine or human basophils. Rat basophilic leukaemia (RBL) cells were passively sensitized with pooled murine allergen-specific IgE-containing sera. Humanized RBL cells and human-stripped basophils were sensitized with pooled patient's sera, which were also used for the CAP-IgE-inhibition assay. Allergen specificity of the sera was determined by immunoblotting.

RESULTS

A good batch-to-batch consistency was found with each assay among all manufacturers and allergens tested. Between different manufacturers, the products showed differences in activity and the various assays indicated an almost identical ranking. However, the biological assays revealed qualitative differences of biological activity or composition of allergen preparations undetectable by IgE-inhibition assay.

CONCLUSIONS

MRAs provide refined information on allergen activity, either confirming the results of IgE-inhibition assay, or indicating differences requiring further investigation, and represent a highly sensitive novel tool in allergen standardization. By using permanently cultivated cell lines, repeated venepuncture to obtain human basophils is avoided. As in the RBL assay, the coefficient of variation for the release values were below 15% and for the ED50 below 25%, the assay is suitable to determine differences that are relevant for batch control purposes.

Structural, immunological and functional properties of natural recombinant Pen a 1, the major allergen of Brown Shrimp, Penaeus aztecus

BACKGROUND

Recombinant allergens are considered the basis for new diagnostic approaches and development of novel strategies of allergen-specific immunotherapy. As Pen a 1 from brown shrimp Penaeus aztecus is the only major allergen of shrimp and binds up to 75% of all shrimp-specific IgE antibodies this molecule may be an excellent model for the usage of allergens with reduced IgE antibody-binding capacity for specific immunotherapy.

AIM

The aim was to clone, express and characterize a full-length recombinant Pen a 1 molecule and compare it with natural Pen a 1 in regard to structural and immunological parameters such as IgE antibody capacity and ability to induce IgE-mediated mediator release.

METHODS

Total RNA was isolated from P. aztecus and a rapid amplification of cDNA ends (5' RACE) was performed to obtain full-length cDNA coding for Pen a 1. Using a gene-specific primer, PCR was performed and full-length cDNA was cloned and sequenced. Recombinant His-tagged Pen a 1 was isolated from Escherichia coli under native conditions by immobilized metal affinity chromatography. Secondary structure of natural and recombinant Pen a 1 was compared by circular dichroism (CD) spectroscopy, and the IgE antibody-binding capacity evaluated by RAST. The allergenic potency was tested by the capability of natural and recombinant Pen a 1 to induce mediator release in a murine and human in vitro model of IgE-mediated type I allergy.

RESULTS

The deduced amino-acid sequence was 284 residues long and amino-acid sequence identities with allergenic and non-allergenic tropomyosins ranged from 80% to 99% and 51% to 58%, respectively. The analysis of the secondary structure of natural and recombinant Pen a 1 by CD spectroscopic analysis showed that both nPen a 1 and rPen a 1 had alpha-helical conformation that is typical for tropomyosin. The IgE antibody binding capacities of nPen a 1 and r Pen a1 were found to be essentially identical by RAST. The mediator release experiments using both wild-type and humanized rat basophilic leukaemia 30/25 cells showed that rPen a 1 and nPen a 1 induced a similar level of mast cell activation.

CONCLUSIONS

Recombinant Pen a 1 and natural Pen a 1 are structurally and immunologically identical and rPen a 1 may be used as the basis for component-resolved diagnosis and the generation of modified shrimp tropomyosin for allergen-specific immunotherapy. The results of the animal studies indicate that C3H/HeJ mice that were sensitized with shrimp extract in combination with cholera toxin as adjuvant may be a suitable model to study shrimp allergy.

MPLA shows attenuated pro-inflammatory properties and diminished capacity to activate mast cells in comparison with LPS

BACKGROUND

Monophosphoryl lipid A (MPLA), a nontoxic TLR4 ligand derived from lipopolysaccharide (LPS), is used clinically as an adjuvant in cancer, hepatitis, and malaria vaccines and in allergen-specific immunotherapy. Nevertheless, its cell-activating effects have not been analyzed in a comprehensive direct comparison including a wide range of different immune cells. Therefore, the objective of this study was the side-by-side comparison of the immune-modulating properties of MPLA and LPS on different immune cells.

METHODS

Immune-activating properties of MPLA and LPS were compared in human monocytes and mast cells (MCs), a mouse endotoxin shock model (ESM), and mouse bone marrow (BM)-derived myeloid dendritic cells (mDCs), T cells (TCs), B cells, and MCs.

RESULTS

In a mouse in vivo ESM and a human ex vivo monocyte activation test (MAT), MPLA induced the same cytokine secretion pattern as LPS (ESM: IL-6, IL-12, TNF-α; MAT: IL-1β, IL-6, TNF-α), albeit at lower levels. Mouse mDCs and ex vivo isolated B cells stimulated with MPLA required a higher threshold to induce TRIF-dependent cytokine secretion (IL-1β, IL-6, IL-10, and TNF-α) than did LPS-stimulated cells. In mDC:DO11.10 CD4 TC cocultures, stimulation with MPLA, but not with LPS, resulted in enhanced OVA-specific IL-4 and IL-5 secretion from DO11.10 CD4 TCs. Unexpectedly, in both human and mouse MCs, MPLA, unlike LPS, did not elicit secretion of pro-inflammatory cytokines.

CONCLUSIONS

Compared to LPS, MPLA induced a qualitatively similar, but less potent pro-inflammatory immune response, but was unable to activate human or mouse MCs.

Assessment of three human FcepsilonRI-transfected RBL cell-lines for identifying IgE induced degranulation utilizing peanut-allergic patient sera and peanut protein extract

Specific IgE sera screening studies are employed to investigate protein cross-reactivity. Such nonfunctional immunochemical methods cannot measure the biological activity of proteins. Therefore, an assay using RBL cells transfected with human FcepsilonRI was developed. Our objective was to evaluate the degranulation of three cell-lines expressing either the alpha-(RBL-hEI(a)-2B12 and RBL-30/25cells) or alpha-, beta-, and gamma-subunits (RBL SX-38) of the human FcepsilonRI by beta-hexosaminidase release. Purified human IgE and serum-derived polyclonal IgE from peanut-allergic subjects following challenge with anti-IgE or peanut protein extract, respectively, were utilized. Robust degranulation was induced in all three: RBL-30/25 (84%), -hEI(a)-2B12 (54%), SX-38 (94%), respectively, using purified IgE+anti-human IgE. Good release (18%, 40-45%, and 65%, respectively) occurred for one peanut-allergic subject+peanut extract with all cell-lines. With serum from three other peanut-allergic subjects, no beta-hexosaminidase release occurred with RBL-hEI(a)-2B12 cells+peanut extract, while only serum from one subject induced good degranulation, 30% and 60%, respectively, with RBL-30/25 and RBL SX 38 cells. Consistent degranulation with a potent food allergen (peanuts) was not observed. The assay's utility in safety assessment, predictive value and reproducibility for evaluating the cross-reactivity of proteins with allergens needs further investigation with additional proteins and well-characterized sera.

Determinants of intensity of participation in leisure and recreational activities by youth with cerebral palsy

OBJECTIVE

To test a model of determinants of intensity of participation in leisure and recreational activities by youth with cerebral palsy (CP).

DESIGN

Prospective cohort study.

SETTING

Children's hospitals (N=7).

PARTICIPANTS

Youth with CP (N=205; age, 13-21y) and their parents. The sample included 107 (57.2%) males and 26 (12.7%) to 57 (27.8%) youth in each of the 5 levels of the Gross Motor Function Classification System (GMFCS).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Youth completed the Children's Assessment of Participation and Enjoyment by means of an interview. Parents completed the Pediatric Outcomes Data Collection Instrument, Family Environment Scale, Coping Inventory, Measure of Processes of Care, a demographic questionnaire, and a services questionnaire.

RESULTS

Structural equation modeling was used to test the model. Fit statistics indicate good model fit. The model explains 35% of the variance in intensity of participation. Path coefficients (P ≤ .05) indicate that higher physical ability, higher enjoyment, younger age, female sex, and higher family activity orientation are associated with higher intensity of participation. GMFCS level and caregiver education have indirect effects on intensity of participation. The path between services and intensity of participation was not significant.

CONCLUSIONS

Participation by youth with CP is influenced by multiple factors. The influence of physical activity supports the importance of activity accommodations and assistive technology for youth who are not capable of improving physical ability. Knowledge of family activity orientation is important for identifying opportunities for participation. The unexplained variance suggests that the model should include other determinants, such as physical accessibility and availability of transportation and community leisure and recreational activities.

Fine mapping of outer membrane protein P2 antigenic sites which vary during persistent infection by Haemophilus influenzae

Antigenic drift of the major outer membrane protein (MOMP) P2 of nonencapsulated Haemophilus influenzae as observed during persistent infections in patients with chronic bronchitis was mimicked in a rabbit model in which H. influenzae persisted in subcutaneous cages. The antigenic drift resulted from amino acid substitutions in potentially surface-exposed loops of MOMP P2. Since in a rabbit model the appearance of antigenic variants was associated with the presence of strain-specific bactericidal antibodies (L. Vogel, B. Duim, F. Geluk, P. Eijk, H. Jansen, J. Dankert, and L. van Alphen, Infect. Immun. 64:980-986, 1996), we determined the epitope specificities of these bactericidal antibodies. The eight loops of MOMP P2 of H. influenzae d1 were separately expressed as fusion proteins with glutathione S-transferase. Sera of rabbits persistently infected with H. influenzae reacted with the loop 5 and loop 6 fusion proteins in immunoblotting and enzyme-linked immunosorbent assay. For fine mapping of the epitopes with pepscan analysis, overlapping synthetic peptides consisting of 12 amino acids were made. Rabbit sera contained antibodies reacting with peptides derived from loop 5 and peptides containing amino acids of the side of loop 6. In addition, MOMP P2 variant-specific reactions with the amino acids located at the tip of loop 6 were detected. The rabbit sera showed variant-specific complement-dependent bactericidal activities, which were eliminated by affinity chromatography with fusion proteins of loop 6 but not of loop 5. We conclude that, during persistence of H. influenzae in rabbits, variant-specific bactericidal antibodies are elicited to the variable tip of MOMP P2 loop 6.

Molecular and immunological characterization of novel weed pollen pan-allergens

BACKGROUND

Pan-allergens like profilins, calcium-binding proteins (CBPs), and nonspecific lipid transfer proteins have been suggested as possible specific markers for multiple pollen sensitizations, and could be used to predict cross-sensitization/poly-sensitization to several pollen allergens. Therefore, the purification and characterization of cross-reacting allergens in pollen is an extremely important task towards correct allergy diagnosis.

METHODS

New pan-allergens were identified by screening a ragweed pollen cDNA library with sera of patients allergic to mugwort pollen. Resulting proteins were cloned, expressed, purified and characterized.

RESULTS

We report complete cDNA sequences of two profilin isoforms (Amb a 8.01 and Amb a 8.02), two isoforms of a 2EF-hand CBP (Amb a 9.01 and Amb a 9.02), a new 3EF-hand CBP (Amb a 10) from ragweed pollen and a 2EF-hand CBP from mugwort (Art v 5). All these proteins were expressed in Escherichia coli, purified to homogeneity and characterized by biochemical and immunological means.

CONCLUSIONS

The identified proteins are novel pan-allergens and can be used as diagnostic markers for polysensitization and used in component-resolved diagnosis.

Chicken embryo model for type III group B beta-hemolytic streptococcal septicemia

A lethal septicemia was induced in 11- and 12-day-old chicken embryos with intravenous inoculation of relatively small numbers of a clinical isolate (GBBHS-III-Bell) or a reference strain (GBBHS-III-D136-C) of group B beta-hemolytic streptococci (GBBHS). GBBHS-III-Bell was more virulent than GBBHS-III-D136-C, and 11-day-old chicken embryos were more susceptible than 12-day-old chicken embryos. Type-specific rabbit antisera protected the embryos from bacterial challenge, and this protective effect was absorbed with homologous but not heterologous GBBHS strains. A heterologous antiserum and normal rabbit sera provided some protection, which could be absorbed with either homologous or heterologous GBBHS strains. The chicken embryo is a suitable animal model for the study of infection and immunity with GBBHS type III.

Birch pollen-related food allergy to legumes: identification and characterization of the Bet v 1 homologue in mungbean (Vigna radiata), Vig r 1

BACKGROUND

Recently allergic reactions to legumes mediated by Bet v 1-homologous food allergens were described for soy and peanut. In this study we assessed allergic reactions to another legume, to mungbean seedlings, and identified its Bet v 1-homologous allergen Vig r 1.

METHODS

Ten patients were selected who had a history of allergic reactions to mungbean seedlings and a respiratory allergy to birch pollen. The Bet v 1 homologue in mungbean seedlings, Vig r 1, was cloned by a PCR strategy, expressed in Escherichia coli, and purified by preparative SDS-PAGE. In all sera, specific IgE against birch pollen, Bet v 1, Bet v 2, Vig r 1, and the Bet v 1 homologues in soy (Gly m 4) and cherry (Pru av 1) was determined by CAP-FEIA. Cross-reactivity of specific IgE with Vig r 1, Bet v 1, Gly m 4, and Pru av 1 was assessed by immunoblot inhibition. Expression of Vig r 1 during development of mungbean seedlings and under wounding stress was analysed by immunoblotting. The Vig r 1 double band was analysed by matrix-assisted laser desorption/ionization time-of-flight and liquid chromatography/tandem mass spectrometry (LC/MS/MS).

RESULTS

All patients were sensitized to birch pollen and Bet v 1, 20% to Bet v 2, and 90% to Gly m 4. Seventy percent of the patients showed IgE binding to a double band at 15 kDa in mungbean extract that was inhibited after pre-incubation of sera with rBet v 1. PCR cloning revealed that the mungbean homologue of Bet v 1 had a molecular weight of 16.2 kDa, a calculated pI of 4.6% and 42.8% amino acid sequence identity with Bet v 1. MS analysis confirmed similarity of the double band with the deduced Vig r 1 sequence, but also indicated the existence of other Vig r 1 isoforms. ImmunoCAP analysis detected IgE against Vig r 1 in 80% of the sera. IgE binding to Vig r 1 was inhibited with Gly m 4 in six of six and with rPru av 1 in four of six patients. Vig r 1 expression occurred during development of seedlings and was increased by wounding stress.

CONCLUSIONS

Food allergy to mungbean seedlings can be caused by primary sensitization to birch pollen and is mediated by Vig r 1 in the majority of the patients with birch pollen-related allergy to mungbean seedlings.

Immunologic characterization of isoforms of Car b 1 and Que a 1, the major hornbeam and oak pollen allergens

BACKGROUND

Birch pollen allergy is one of the most common causes of spring pollinosis often associated with hypersensitivity reactions to pollen of other Fagales species. Yet, only the major disease eliciting allergens of alder and hazel have been fully characterized. Therefore, the aim of this study was to perform cloning, expression and immunologic characterization of the Bet v 1 homologues from oak (Que a 1) and hornbeam (Car b 1).

METHODS

The isoform pattern of Car b 1 and Que a 1 was analyzed by proteomics using 2D gel electrophoresis and LC ESI-QTOF MS. Isoallergens showing high IgE-binding were cloned and expressed in Escherichia coli. IgE-binding activity of the recombinant proteins was determined by enzyme-linked immunosorbent assay (ELISA) and basophil mediator release assays using serum samples from patients mainly exposed either to oak and hornbeam or to birch pollen. Cross-reactivity of the allergens was further investigated at the T-cell level.

RESULTS

Dominant isoforms of Car b 1 and Que a 1, identified by mass spectrometry, showed different IgE-binding properties when testing Fagales pollen-allergic patients living in birch-free areas as compared to birch-sensitized individuals.

CONCLUSION

Tree pollen-allergic patients who are primarily exposed to Fagales pollen other than birch reacted stronger with rCar b 1 and rQue a 1 than with rBet v 1, as determined by inhibition ELISA and basophil mediator release assays. Thus, rCar b 1 and rQue a 1 allergens should be considered for improving molecule-based diagnosis and therapy of tree pollen allergies manifesting in birch-free areas.

Infections due to gentamicin-resistant Staphylococcus aureus strain in a nursery for neonatal infants

An apparently homogeneous strain of Staphylococcus aureus resistant to gentamicin (Gmr), kanamycin, tobramycin, and sisomicin, but susceptible to amikacin and netilmicin, caused multiple infections in neonatal infants in a special care nursery. Nasal cultures revealed a high rate of carriage of the Gmr staphylococcus in infants without clinical infection. Segregating patients according to a modified cohort system and use of careful aseptic techniques led to apparent elimination of the Gmr strain. The resistance to aminoglycosides in this strain was mediated by an aminoglycoside 6'-N-acetyltransferase and a gentamicin phosphotransferase. Genetic determinants for these enzymes were borne on a circular covalently closed plasmid of approximately 11 megadaltons. These resistance determinants closely resemble those found in isolates of S. aureus that have caused nosocomial infections in patients in Europe.

Opsonic antibodies to outer membrane protein P2 of nonencapsulated Haemophilus influenza are strain specific

The ability of monoclonal antibodies (MAbs) specific for variable and conserved epitopes of outer membrane protein (OMP) P2 (b,c) of nonencapsulated Haemophilus influenza to promote opsonophagocytosis of this bacterium by human polymorphonuclear leucocytes (PMNs) was determined by flow cytometry. MAbs rendering PMNs fluorescent because of association with fluorescein isothiocyanate-labelled bacteria were defined as stimulating opsonophagocytosis. Opsonophagocytosis was dependent on the presence of both antibodies and complement. Of the 14 MAbs directed to the variable parts of OMP P2 (L. van Alphen, P. Eijk, L. Geelen-van den Broek, and J. Dankert, Infect. Immun. 59:247-252, 1991), 9 stimulated opsonophagocytosis. Four of the five nonopsonophagocytic MAbs that were immunoglobulin G1 were unable to cause complement activation. The MAbs promoting opsonophagocytosis included MAbs specific for one or more OMP P2 antigenic variants of H. influenzae strains isolated from patients with chronic bronchitis during persistent infection. MAbs cross-reacting in enzyme-linked immunosorbent assays with nonrelated H. influenzae did not promote opsonophagocytosis of strains from other patients. Opsonophagocytosis was not observed in the presence of three MAbs reacting with OMP P2 epitopes common in H. influenzae. These results indicate that OMP P2-dependent opsonophagocytosis of nonencapsulated H. influenzae is strictly strain specific.

Performance of phenotypic and genotypic methods to determine the clinical relevance of serial blood isolates of staphylococcus epidermidis in patients with septicemia

Five typing methods, including biotyping (API ID32; BioMérieux, Marcy l'Etoile, France), quantitative antibiogram typing based on actual zone sizes, plasmid typing, randomly amplified polymorphic DNA (RAPD) analysis (with primer M13 and primer set ERIC-2-1026), and pulsed-field gel electrophoresis (PFGE), were compared with a previously performed method of DNA fingerprinting by AFLP (amplified fragment length polymorphism analysis) for their performance in the typing of blood isolates of Staphylococcus epidermidis. Sixteen epidemiologically unrelated strains and 11 sets of four blood culture isolates from 11 patients with septicemia were used. The stabilities and reproducibilities of the patterns, the discriminatory capacities of the methods, and the ability to apply the methods to blood culture isolates were used as performance criteria. All strains tested were typeable by each method, and the patterns were stable and reproducible. The numbers of different types within the collection of 16 epidemiologically different isolates were 5 by biotyping, 14 by antibiogram typing, 4 by plasmid typing, 9 by the RAPD assay (combination of results with primer M13 and primer set ERIC-2-1026), and 16 by PFGE. Within the 11 sets of four blood culture isolates the types found by quantitative antibiogram typing, plasmid typing, and PFGE were unique for each set, whereas by biotyping and RAPD analysis some types were observed in more than one set. The results of biotyping did not correspond with the results of the other methods or the results of AFLP. For 6 of the 11 sets, the results of all methods except those of biotyping corresponded completely. Quantitative antibiogram typing, PFGE, and AFLP proved to be the most accurate of the six typing methods tested.