Arthrosonography of hip and knee joints in the follow up of juvenile rheumatoid arthritis

OBJECTIVE

To evaluate sensitivity of arthrosonography of hip and knee joints for monitoring disease activity in juvenile rheumatoid arthritis (JRA).

METHODS

Twenty eight patients with JRA with active disease at entry in 15 hips and 38 knee joints were followed up three times in intervals of 4-6 weeks. Sonographic, clinical, and laboratory findings were documented at the same time in clinically active and inactive disease. As controls of the sonographic variables 10 children without a history of arthritis were examined by ultrasound.

RESULTS

In active arthritis of the hip joint 19/31 (61%) examinations showed a pathological widening of the synovial joint space. There was no significant correlation between sonographic and clinical measures of disease activity in coxitis. Marked effusion within the suprapatellar pouch was seen in 87% and thickening of the synovial membrane in 92% of cases of active gonarthritis in patients with JRA. There was a significant difference in the number of patients with joint effusion and in the mean joint effusion between patients with clinically active gonarthritis at entry and inactive arthritis at follow up (p<0.001). In contrast, synovial thickening persisted in about 80% after induction of clinical remission.

CONCLUSION

The data confirm the high sensitivity of arthrosonography in imaging changes in hip and knee joints of patients with JRA. Sonographic effusion of the knee provided the highest correlation with measures of clinical disease activity. Further prospective studies should evaluate whether persistent thickening of the synovial membrane detected by ultrasound in clinically inactive arthritis indicates residual inflammatory activity and an increased risk of relapse.

[Pulmonary aspergillosis as initial manifestation of septic granulomatosis (chronic granulomatous disease, CGD) in a premature monozygotic female twin and FDG-PET diagnosis of spread of the disease]

PURPOSE

To present the unusual case of chronic granulomatous disease (CGD) manifestating as pulmonal aspergillosis in female enzygotic twins during the neonatal period. To demonstrate and to discuss the complex diagnosis and the diagnostic value of FDG-PET in monitoring the spread and activity of the disease.

PATIENTS

Plain chest x-ray and CT of the lung showed multiple, mostly round lesions in one of the former preterm twins at the age of 8 weeks. The girl with known ASD II was then suffering from dyspnoea and recurrent pulmonary infections. Because of the imaging findings invasive pulmonary aspergillosis due to an underlying immunodeficiency was suspected.

RESULTS

Aspergillosis was confirmed histologically and microbiologically by specimens taken from an open lung biopsy. Because of coexisting granulocytic dysfunction the diagnosis of CGD was made. This diagnosis was equally confirmed by noninvasive methods in the asymptomatic sister. FDG-PET did not show any evidence of extra-pulmonary spread of disease.

CONCLUSION

CGD can present as isolated pulmonal aspergillosis even in the neonatal period when an immunodeficiency is discussed. In enzygotic twins screening of the asymptomatic twin is mandatory. FDG-PET is a useful tool in screening for spread of the disease and in evaluating disease activity.

Periventricular cystic lesions in a preterm infant after a car accident during pregnancy

We report on a preterm infant born at 30+5/7 gestational weeks who developed severe cystic cerebral lesions after exposure to a car accident one day before delivery. The literature on car accidents during pregnancy is reviewed with specific focus on neonatal neurological outcome.

Acute and long-term effects of booster immunisation on frequencies of antigen-specific memory B-lymphocytes

In search for a parameter that is predictive of long-term immunity, we analysed the influence of booster immunisations on frequencies of circulating memory B-lymphocytes. Specific IgG-secreting B-cells were determined by ELISPOTassay in 13 healthy adults, using diphtheria and tetanus toxoid as model antigens. Our results show that memory B-cells accumulate with every immunisation dose and remain elevated over several years. In addition, secondary B-cell responses were studied during the first 90 days after diphtheria re-immunisation. A significant indirect correlation was found between the number of previous boosters and the magnitude of specific B-cell expansion. In contrast, effects of booster immunisations did not correlate likewise with antigen-specific serology. Hence, this study illustrates that frequencies of antigen-specific B-lymphocytes can be used as an indirect measure for immunological memory. This parameter could be helpful to find scientifically based immunisation strategies for currently available and novel vaccines.

Interaction of Neisseria meningitidis with human dendritic cells

Infection with Neisseria meningitidis serogroup B is responsible for fatal septicemia and meningococcal meningitis. The severity of disease directly correlates with the production of the proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1), IL-6, and IL-8. However, the source of these cytokines has not been clearly defined yet. Since bacterial infection involves the activation of dendritic cells (DCs), we analyzed the interaction of N. meningitidis with monocyte-derived DCs. Using N. meningitidis serogroup B wild-type and unencapsulated bacteria, we found that capsule expression significantly impaired neisserial adherence to DCs. In addition, phagocytic killing of the bacteria in the phagosome is reduced by at least 10- to 100-fold. However, all strains induced strong secretion of proinflammatory cytokines TNF-alpha, IL-6, and IL-8 by DCs (at least 1,000-fold at 20 h postinfection [p.i.]), with significantly increased cytokine levels being measurable by as early as 6 h p.i. Levels of IL-1beta, in contrast, were increased only 200- to 400-fold at 20 h p.i. with barely measurable induction at 6 h p.i. Moreover, comparable amounts of cytokines were induced by bacterium-free supernatants of Neisseria cultures containing neisserial lipooligosaccharide as the main factor. Our data suggest that activated DCs may be a significant source of high levels of proinflammatory cytokines in neisserial infection and thereby may contribute to the pathology of meningococcal disease.

Mannose-binding lectin regulates the inflammatory response of human professional phagocytes to Neisseria meningitidis serogroup B

The influence of the innate immune protein mannose-binding lectin (MBL) on the response of human phagocytes to Neisseria meningitidis was investigated. MBL increased the association of killed meningococci with neutrophils, monocytes, and macrophages by increasing the proportion of cells that recognized bacteria. MBL down-regulated the normal change in expression of the leukocyte adhesion molecules CD11b and CD62L. In an ex vivo model, the addition of MBL to the blood of MBL-deficient donors influenced the production of monocyte-derived inflammatory cytokines. The addition of high concentrations of MBL (>6 microg/mL) profoundly decreased the production of interleukin (IL)-6, IL-1beta, and tumor necrosis factor-alpha by monocytes in response to meningococci, whereas lower concentrations enhanced the production of IL-6 and IL-1beta. These results suggest that MBL not only is involved in complement activation but also is a potent regulator of inflammatory pathways and, as such, may affect the severity of meningococcal disease.

Effect of the growth medium on the in vitro antifungal activity of micafungin (FK-463) against clinical isolates of Candida dubliniensis

Micafungin (FK-463), a member of the new candin family of antifungal agents, was highly active against clinical isolates of Candida albicans and Candida dubliniensis. The in vitro activity of micafungin suggested that it was more potent than fluconazole, flucytosine, amphotericin B or voriconazole against C. albicans, and comparable or moderately less effective against C. dubliniensis isolates when high-resolution medium (HR) was used. Lower MICs of micafungin were recorded when RPMI 2% or AM3 2% media were used, indicating an influence of the growth medium on the MIC.

Analysis of transcriptional control mechanisms of capsule expression in Neisseria meningitidis

The major virulence factor which contributes to the survival of Neisseria meningitidis in the blood stream and the cerebrospinal fluid is the capsular polysaccharide. Expression of the capsule genes of N. meningitidis serogroups B, C, W-135 and Y is controlled by an intergenic region separating the capsule biosynthesis operon (siaA-D) and the capsule transport operon (ctrA-D). To further investigate capsule expression in N. meningitidis we amplified and sequenced the intergenic region of 42 meningococcal isolates of different serogroups. Sequence variations were found mainly in a repeat region preceding the siaA start codon. Correlation between sequence variation and serogroup could not be observed. To measure the transcriptional and translational activity of the respective intergenic regions we performed transcriptional and translational fusions with the lacZ gene integrated into the chromosome of N. meningitidis. Sequence variations preceding the siaA start codon had no effect on beta-galactosidase activity. Different in vitro growth conditions such as temperature, glucose concentration, osmolarity, pH and iron concentration also did not influence beta-galactosidase activity. Sequential deletions of the intergenic region showed that an Up-like element adjacent to the predicted -35 box is necessary for full transcriptional activity. The deletion of the untranslated region preceding the siaA start codon led to a threefold higher beta-galactosidase activity compared with the full-length construct suggesting that the respective region may be involved in capsule regulation.

Platelet glycoprotein complex Ia/IIa antibodies cause neonatal alloimmune thrombocytopenia but do not inhibit megakaryopoiesis and platelet recovery after allogeneic cord blood stem cell transplantation

A sibling cord blood (CB) transplantation was performed in a boy with Wiskott-Aldrich syndrome. The CB (31 x 10(6) CD34(+) cells) derived from a newborn sister with neonatal alloimmune thrombocytopenia (NAIT) with 40,000 platelets/microl, caused by a maternal anti-HPA-5b and HLA-A2 antibody. Maternal serum did not inhibit clonogenicity after in vitro testing of megakaryopoiesis. Accordingly, this CB was accepted for sibling transplantation. The transplantation showed a good course with fast and sustained hematopoietic reconstitution (granulocytes >500/microl on day +16, platelets >50,000/microl on day +30). This case demonstrates a successful CB transplantation from a donor suffering from NAIT.

Selective cell loss in Edinger-Westphal in asymptomatic elders and Alzheimer's patients

Exaggerated pupillary response to a low concentration of cholinergic antagonists has been suggested as an early marker for Alzheimer's Disease (AD). To examine the anatomic basis of this phenomenon, we determined possible neuropathological changes in the Edinger-Westphal (EW) nucleus, a midbrain neural center with a significant functional role in the control of pupil size. Stereologically determined neuronal numbers within the EW were counted in individuals with pathologically confirmed AD, control cases with no AD-type pathology, and subjects with AD pathology not meeting diagnostic criteria for AD. The EW of AD patients displayed a marked and striking neuronal loss when compared with controls. In contrast, the number of neurons in the somatic portion of the nucleus of the third cranial nerve (NCNIII) remained intact. The EW in brains from clinically normal individuals with evidence of early AD-type pathology also displayed a significant and selective loss of neurons. The magnitude of EW neuronal loss in the latter group was smaller than that observed in AD. These findings suggest that pupillary hypersensitivity in AD may be caused by abnormalities in the EW. Neuronal loss and pathology within the EW in a subpopulation of clinically silent controls with pathologic findings consistent with early-stage AD constitutes a possible explanation for the reported exaggerated pupil response in some normal elderly subjects.

Autologous peripheral blood stem cell transplantation and anti-B-cell directed immunotherapy for refractory auto-immune haemolytic anaemia

We report the clinical course of a 6.5-year-old boy with refractory auto-immune haemolytic anaemia. Due to failure of conventional immunosuppressive therapy, an autologous peripheral blood stem cell transplantation was performed. The conditioning regimen consisted of cyclophosphamide and anti-thymocyte globulin. The patient was reinfused with 2.6 x 10(6) CD34 positive selected, B- and T-cell-depleted peripheral blood stem cells per kg body weight. He showed a partial response with a reduced demand for red blood cell transfusions. However, due to persistence of the haemolytic process he was started on rituximab therapy on day +40 post-transplant. Following two doses of rituximab, the patient improved rapidly and developed a sustained complete response. After 10 months, haemolysis recurred and responded again to rituximab therapy without the necessity for red blood cell transfusions. 15 months after initial antibody treatment, however, the patient developed a second relapse which was now refractory to rituximab therapy although CD20+ B-lymphocytes were cleared from the peripheral blood.

CONCLUSION

Our case report suggests that rituximab and autologous peripheral blood stem cell transplantation are important though not curative elements in the treatment of patients with severe auto-immune haemolytic anaemia who are refractory to conventional immunosuppressive therapy.

Complex O-acetylation in Legionella pneumophila serogroup 1 lipopolysaccharide. Evidence for two genes involved in 8-O-acetylation of legionaminic acid

A putative gene encoding an O-acetyl transferase, lag-1, is involved in biosynthesis of the O-polysaccharide (polylegionaminic acid) in some Legionella pneumophila serogroup 1 strains. To study the effect of the presence and absence of the gene on the O-polysaccharide O-acetylation, lag-1 from strain Philadelphia 1 was expressed in trans in the naturally lag-1-negative OLDA strain RC1, and immunoblot analysis revealed that the lag-1-encoded O-acetyl transferase is active. O-Polysaccharides of different size were prepared from the lipopolysaccharides of wild-type and transformant strains by mild acid degradation followed by gel-permeation chromatography. Using NMR spectroscopy and MALDI-TOF mass spectrometry, it was found that O-acetylation of the first three legionaminic acid residues next to the core occurs in the short-chain O-polysaccharide (<10 sugars) from both strains. Hence, there is another O-acetyl transferase encoded by a gene different from lag-1. In the longer-chain O-polysaccharide, a legionaminic acid residue proximal to the core is N-methylated and could be further 8-O-acetylated in the lag-1-dependent manner. Only strains expressing a functional lag-1 gene were recognized in Western blot analysis by monoclonal antibody 3/1 requiring 8-O-acetylated polylegionaminic acid for binding. The highly O-acetylated outer core region of the lipopolysaccharide is involved in the epitope of another serogroup 1-specific monoclonal antibody termed LPS-1. The O-acetylation pattern of the L. pneumophila serogroup 1 core oligosaccharide was revised using MALDI-TOF mass spectrometry. lag-1-independent O-acetylation of the core and short-chain O-polysaccharide was found to be a common feature of L. pneumophila serogroup 1 strains. The biological importance of conserved lag-1-independent and variable lag-1-dependent O-acetylation is discussed.

Molecular techniques for the investigation of meningococcal disease epidemiology

Meningococcal disease remains a major cause of childhood morbidity and mortality world wide and no comprehensive vaccine is available against the causative organism, Neisseria meningitidis. Molecular studies of the diversity of this bacterium have provided a number of key insights into its biology, which have implications for control of meningococcal disease. These have included the identification of hyperinvasive lineages and the correlation of genetic type with antigenic type and disease epidemiology. In practical terms, such studies have enabled the application of DNA-based technologies in the development of improved methods for diagnosis and epidemiological monitoring. These data are of especial importance with the current, and ongoing, development and introduction of new meningococcal vaccines.

Use of recombinant mitogillin for improved serodiagnosis of Aspergillus fumigatus-associated diseases

During human infection, Aspergillus fumigatus secretes a 18-kDa protein that can be detected as an immunodominant antigen in the urine of infected patients. Recently, this protein was shown to be mitogillin, a ribotoxin that cleaves a single phosphodiester bond of the 29S rRNA of eukaryotic ribosomes. We proved the immunogenic capacity of mitogillin in a rabbit animal model, indicating its usefulness as an antigen for serological diagnosis of invasive aspergillosis. The mitogillin gene from A. fumigatus was transferred from plasmid pMIT+ to expression vector pQE30 and expressed in Escherichia coli as a fusion protein. Purified recombinant mitogillin was recognized by serum immunoglobulin G (IgG) of polyclonal rabbit sera that were obtained by immunization with purified native mitogillin. Consequently, we developed an enzyme-linked immunosorbent assay for detection of IgG, IgM, and IgA antibodies to recombinant mitogillin. In serum samples of patients suffering from aspergilloma (AO; n = 32), invasive pulmonary aspergillosis (IPA; n = 42), or invasive disseminated aspergillosis (IDA; n = 40), a good correlation of production of IgG antibody against mitogillin and clinical disease was observed (for patients with AO, 100% [32 of 32] were positive; for patients with IPA, 64% [31 of 42] were positive; for patients with IDA, 60% [24 of 40] were positive). In contrast, positive titers for serum IgG and IgM antibodies against mitogillin were found in only 1.3% of the serum samples of healthy volunteers and positive titers for IgA antibody were found in only 1.0% of the serum samples of healthy volunteers (n = 307; specificity = 95.4%). These results indicate that recombinant mitogillin expressed in E. coli can be used for improvement of the serodiagnosis of A. fumigatus-associated diseases.

Genetic diversity of Neisseria lactamica strains from epidemiologically defined carriers

We assessed the genetic diversity of 26 Neisseria lactamica strains from epidemiologically related sources, i.e., groups of kindergartens and primary schools in three Bavarian towns, by the partial sequencing of the argF, rho, recA, and 16S ribosomal genes. We found a total of 17 genotypes, of which 12 were found only in one strain. The genotypes comprised 5 alleles of the argF gene, 9 of rho, 8 of recA, and 10 of the 16S ribosomal DNA. Sequence analysis by determination of homoplasy ratios and split decomposition analysis revealed abundant recombination within N. lactamica.

Genetic isolation of meningococci of the electrophoretic type 37 complex

Neisseria meningitidis (the meningococcus) is a naturally competent bacterial species in which intra- and interspecific horizontal gene transfer is a major source of genetic diversity. In strains of the electrophoretic type 37 (ET-37) complex and of the A4 cluster, we identified genomic DNA coding for a novel restriction-modification system and for the tail of a previously unidentified prophage. Furthermore, a novel 7.2-kb DNA segment restricted to clones of the ET-37 complex and the A4 cluster was isolated and shown to occur both as a plasmid (pJS-B) and as a chromosomal integration. Neither the genomic loci nor pJS-B was present in ET-5 complex, lineage 3, or serogroup A meningococci. The differential distribution of the DNA segments described herein, as well as of opcA, porB, nmeAI, nmeBI, and nmeDI described previously, supports the concept of genetic isolation of hypervirulent lineages responsible for most cases of serogroup C disease worldwide.

Molecular and phenotypic identification of the yeast pathogen Candida dubliniensis

Candida dubliniensis is an emerging yeast pathogen generally misclassified as Candida albicans by standard diagnostic procedures. This study examined the efficiency of molecular identification, based on a discriminative PCR test, in a prospective study on the prevalence of C. dubliniensis among 103 oropharyngeal isolates from HIV-infected individuals or transplant recipients, and 30 vaginal isolates. All of the isolates had been classified as C. albicans by standard laboratory procedures. The PCR was evaluated in a blinded fashion against classification achieved by sequencing rDNA. Sequencing results corresponded 100% to the results of the discriminative PCR, indicating the validity of this rapid test. Twenty-one C. dubliniensis isolates were identified, all of them from HIV-infected individuals (prevalence 30%). The internal transcribed spacer regions of the C. dubliniensis isolates were sequenced. Phenotypic features of C. dubliniensis, namely abundant chlamydospore formation, atypical color on CHROMagar, growth defect at 45 degrees C, and colony morphology on Staib agar, were evaluated in a blinded fashion with respect to their discriminative potential, facilitating the design of further epidemiological studies. Carbohydrate assimilation patterns were determined for C. dubliniensis with a novel automated system showing that, in contrast to previous reports, C. dubliniensis is able to utilize D-xylose and trehalose. In evaluating these tests we present a rational approach to identification of the new species and characterization of C. dubliniensis isolates.

Diagnostics of neisseriaceae and moraxellaceae by ribosomal DNA sequencing: ribosomal differentiation of medical microorganisms

Fast and reliable identification of microbial isolates is a fundamental goal of clinical microbiology. However, in the case of some fastidious gram-negative bacterial species, classical phenotype identification based on either metabolic, enzymatic, or serological methods is difficult, time-consuming, and/or inadequate. 16S or 23S ribosomal DNA (rDNA) bacterial sequencing will most often result in accurate speciation of isolates. Therefore, the objective of this study was to find a hypervariable rDNA stretch, flanked by strongly conserved regions, which is suitable for molecular species identification of members of the Neisseriaceae and Moraxellaceae. The inter- and intrageneric relationships were investigated using comparative sequence analysis of PCR-amplified partial 16S and 23S rDNAs from a total of 94 strains. When compared to the type species of the genera Acinetobacter, Moraxella, and Neisseria, an average of 30 polymorphic positions was observed within the partial 16S rDNA investigated (corresponding to Escherichia coli positions 54 to 510) for each species and an average of 11 polymorphic positions was observed within the 202 nucleotides of the 23S rDNA gene (positions 1400 to 1600). Neisseria macacae and Neisseria mucosa subsp. mucosa (ATCC 19696) had identical 16S and 23S rDNA sequences. Species clusters were heterogeneous in both genes in the case of Acinetobacter lwoffii, Moraxella lacunata, and N. mucosa. Neisseria meningitidis isolates failed to cluster only in the 23S rDNA subset. Our data showed that the 16S rDNA region is more suitable than the partial 23S rDNA for the molecular diagnosis of Neisseriaceae and Moraxellaceae and that a reference database should include more than one strain of each species. All sequence chromatograms and taxonomic and disease-related information are available as part of our ribosomal differentiation of medical microorganisms (RIDOM) web-based service (http://www.ridom.hygiene.uni-wuerzburg.de/). Users can submit a sequence and conduct a similarity search against the RIDOM reference database for microbial identification purposes.

Chromosomal insertion and excision of a 30 kb unstable genetic element is responsible for phase variation of lipopolysaccharide and other virulence determinants in Legionella pneumophila

We recently described the phase-variable expression of a virulence-associated lipopolysaccharide (LPS) epitope in Legionella pneumophila. In this study, the molecular mechanism for phase variation was investigated. We identified a 30 kb unstable genetic element as the molecular origin for LPS phase variation. Thirty putative genes were encoded on the 30 kb sequence, organized in two putative opposite transcription units. Some of the open reading frames (ORFs) shared homologies with bacteriophage genes, suggesting that the 30 kb element was of phage origin. In the virulent wild-type strain, the 30 kb element was located on the chromosome, whereas excision from the chromosome and replication as a high-copy plasmid resulted in the mutant phenotype, which is characterized by alteration of an LPS epitope and loss of virulence. Mapping and sequencing of the insertion site in the genome revealed that the chromosomal attachment site was located in an intergenic region flanked by genes of unknown function. As phage release could not be induced by mitomycin C, it is conceivable that the 30 kb element is a non-functional phage remnant. The protein encoded by ORF T on the 30 kb plasmid could be isolated by an outer membrane preparation, indicating that the genes encoded on the 30 kb element are expressed in the mutant phenotype. Therefore, it is conceivable that the phenotypic alterations seen in the mutant depend on high-copy replication of the 30 kb element and expression of the encoded genes. Excision of the 30 kb element from the chromosome was found to occur in a RecA-independent pathway, presumably by the involvement of RecE, RecT and RusA homologues that are encoded on the 30 kb element.

Capsular operons

The major factor determining the different pathogenicities of meningococci and their close relatives, the gonococci, is the polysaccharide capsule. The capsule protects meningococci from complement attack and phagocytosis and is indispensable for systemic spread of the bacteria during sepsis and meningitis (1-5). The influence of the capsule on transmission of the bacteria, colonization of the human host, entry into the bloodstream, and passage of the blood-brain barrier (BBB), respectively, is less well-understood. Colonizing meningococci may be acapsular (6,7), and at least in serogroup B meningococci, there is evidence that transient loss of encapsulation owing to genetic-switching mechanisms facilitates entry into epithelial cells (8,9). Characterization of meningococcal capsules in disease and carrier isolates is important as part of the meningococcal typing scheme of outbreak isolates. Typing is performed to determine the transmission of index strains. Capsular serogrouping is of particular importance in the assessment of the suitability of vaccination in outbreak management (reviewed in ref. 10). This chapter describes serological and molecular techniques used for the determination of serogroups and capsular genotypes.

mRNA trans-splicing in the human parasitic cestode Echinococcus multilocularis

An identical 36-nucleotide exon was identified at the 5' termini of different mRNAs from the cestode Echinococcus multilocularis. We provide evidence that this exon constitutes a new spliced leader (SL) that is obviously trans-spliced to echinococcal pre-mRNAs, donated by a non-polyadenylated, trimethylguanosine-capped SL-RNA of 104 nucleotides. Sequence comparisons indicated that cestode and trematode SLs are likely to be derived from a common ancestor gene. No conservation was, however, observed concerning the spectrum of mRNAs that is trans-spliced in cestodes and trematodes, indicating that trans-splicing of a particular flatworm mRNA is not correlated with the function of the encoded protein. We also show that the echinococcal gene elp, encoding a member of the ezrin/radixin/moesin protein family, is expressed via two alternative transcripts, spliced either cis or trans at an identical splice acceptor site. This was accompanied by the formation of different elp primary transcripts, harboring a complete or a truncated upstream intron, which supports the hypothesis that alternative cis/trans-splicing depends on the presence or absence of an upstream splice donor site. A putative SL gene was also identified on chromosomal DNA of Echinococcus granulosus, indicating widespread utilization of trans-splicing in the genus.

Twenty-four hour intraesophageal pH monitoring in children and adolescents with scleroderma and mixed connective tissue disease

OBJECTIVE

To investigate esophageal dysmotility and gastroesophageal reflux, which are important, but often occult features of gastrointestinal (GI) involvement in children and adolescents with mixed connective tissue disease (MCTD) and scleroderma.

METHODS

We carried out intraesophageal 24 h pH monitoring of 14 patients with scleroderma and MCTD.

RESULTS

We observed an elevated reflux index in 64% of the patients. An increased number of reflux events was found in 85%. Reflux events > 5 min were noted in 50% of the patients, which is indicative of possible development of esophagitis. Only 3 patients presented clinical symptoms. Four of 5 patients with localized scleroderma revealed a pathological reflux index. We found no relationship between gastroesophageal reflux, age of patients, duration of disease, and Raynaud's phenomenon.

CONCLUSION

GI involvement in children with scleroderma or MCTD is more frequent than clinical symptoms indicate. An active diagnostic investigation for GI dysmotility and gastroesophageal reflux is necessary to detect these complications.

A subgroup-specific evaluation of the efficacy of intraarticular triamcinolone hexacetonide in juvenile chronic arthritis

OBJECTIVE

To determine the subgroup-specific differences of intraarticular triamcinolone hexacetonide (TH) in the treatment of joint inflammation in patients with juvenile chronic arthritis (JCA).

METHODS

A retrospective review of 194 children of all subgroups of JCA, treated by a single or repeated TH injection between 1989 to 1994. Efficacy and duration of benefit were evaluated after a mean duration of 3, 15, 30, and 64 weeks.

RESULTS

In all, 1439 TH injections were given to 194 patients; 368 of these were reinjections. The median duration of improvement of all injections was 74 weeks. Responses were significantly different among subgroups (p = 0.0001): there were 121 weeks of efficacy in early-onset pauciarticular JCA type I (223 injections), 47 weeks in late-onset pauciarticular JCA type II (190 injections), 105 weeks in rheumatoid factor negative polyarticular JCA (445 injections), 63 weeks in rheumatoid factor positive polyarticular JCA (127 injections), and 36 weeks in systemic JCA (413 injections). Forty-one injections were done in other rheumatic diseases. In relation to this result there were also differences with regard to joint groups, antinuclear antibody (ANA) and HLA-B27 status, and sex. Side effects were rare: infections of skin or joints were not noted; skin and lipoatrophy were seen after 15 injections, necrosis of the hip in one case, luxation of 2 shoulders of one patient, and periarticular calcification in 3 patients.

CONCLUSION

Intraarticular TH is an effective therapy for inflammatory joint disease in all subgroups of JCA. The risk of major complications is low. The median duration of improvement depends on the subgroup of the disease.

Successful treatment of mycobacterium avium osteomyelitis and arthritis in a non-immunocompromised child

In non-immunocompromised children, infections with mycobacterium avium complex (MAC) are rare, except for cervical lymphadenitis. We report here a 34-month-old boy who developed osteomyelitis and septic arthritis due to MAC. No findings could be revealed for immunodeficiency. He was treated successfully for 12 months with combined therapy consisting of clarithromycin, rifabutin and protionamid.

[Musculoskeletal pain]

BACKGROUND

In paediatrics, numerous diseases present with the leading symptom of muscular, articular, or bone-related pain. The pain as such is seldom diagnostic with regard to pain etiology. Regularly, the significance of inflammatory as well as non-inflammatory pain is underestimated.

CLASSIFICATION OF MUSCULOSKELETAL DISEASES

We present 4 case reports, illustrating the classification of musculoskeletal diseases into 4 main groups, being the basis for the modelling of disease, and pain treatment.

THERAPY

Pain therapy is either symptomatic or based on specific pathophysiology. Pain therapy consists of the moduls analgesics, antiphlogistics, physiotherapy, psychosocial support, and complementary therapies. We give advice on differential therapy. A transparent team-oriented concept comprising physicians, physiotherapists, ergotherapists, psychologists, and social workers is the basis for any successful long-term therapy. Regular outpatient visits in consent with the family doctor are mandatory as are education and treatment periods on ward. We encourage our patients to join formal self-supportive patient groups.

Molecular responses to changes in the environmental pH are conserved between the fungal pathogens Candida dubliniensis and Candida albicans

In this work we cloned CdPHR1 and CdPHR2 from the human fungal pathogen Candida dubliniensis. The two genes are homologues to the pH-regulated genes PHR1 and PHR2 from Candida albicans. The pH-dependent pattern of expression of CdPHR1 and CdPHR2 was conserved in C. dubliniensis. CdPHR1 could be shown to be functionally equivalent to PHR1. The pH-regulated mode of expression was maintained when CdPHR1 was integrated in C. albicans. This indicates a fundamentally similar mode of expressional regulation in the two species. CdPHR1 was furthermore capable of reversing the aberrant phenotype of a Saccharomyces cerevisiae GAS1 deletion mutant. In this species, however, expression of CdPHR1 was no longer under control of the external pH. Expression of CdPHR1 was not detected when it was introduced into Aspergillus nidulans. In conclusion, C. dubliniensis and C. albicans respond to changes in the environmental pH with a change in cell shape and differential gene expression.

Dominant active alleles of RIM101 (PRR2) bypass the pH restriction on filamentation of Candida albicans

Morphological development of the fungal pathogen Candida albicans is profoundly affected by ambient pH. Acidic pH restricts growth to the yeast form, whereas neutral pH permits development of the filamentous form. Superimposed on the pH restriction is a temperature requirement of approximately 37 degrees C for filamentation. The role of pH in development was investigated by selecting revertants of phr2Delta mutants that had gained the ability to grow at acid pH. The extragenic suppressors in two independent revertants were identified as nonsense mutations in the pH response regulator RIM101 (PRR2) that resulted in a carboxy-terminal truncation of the open reading frame. These dominant active alleles conferred the ability to filament at acidic pH, to express PHR1, an alkaline-expressed gene, at acidic pH, and to repress the acid-expressed gene PHR2. It was also observed that both the wild-type and mutant alleles could act as multicopy suppressors of the temperature restriction on filamentation, allowing extensive filamentation at 29 degrees C. The ability of the activated alleles to promote filamentation was dependent upon the developmental regulator EFG1. The results suggest that RIM101 is responsible for the pH dependence of hyphal development.

Activities of the EM10 protein from Echinococcus multilocularis in cultured mammalian cells demonstrate functional relationships to ERM family members

The ezrin-radixin-moesin (ERM) homolog EM10 is expressed by the larval stage of the parasite E. multilocularis and shows 46.9% overall identity in the primary structure with human ezrin. To determine whether EM10 has similar activities to ERM proteins, we investigated properties of the protein expressed in mammalian cells. In particular, we transiently expressed haemagglutinin-tagged (HA-tagged) versions of the full-length EM10 as well as the amino- and the carboxy-terminal halves of EM10 in HtTA-1 cells. In addition we stably transfected NIH-3T3 cells with untagged full-length EM10. The data demonstrate that EM10 polypeptides behave like their corresponding portions of radixin when transiently expressed in mammalian cells. The full-length and amino-terminal EM10 polypeptides were localized to cortical structures. Cells expressing the carboxy-terminal polypeptide of EM10 showed long actin-filled protrusions. Cells expressing full-length EM10 showed a reduction in endogenous moesin-staining at cortical structures. In stably transfected NIH-3T3 cells EM10 was not crisply localized but rather was diffuse throughout the cytoplasm. These cells showed a conspicuous loss of stress-fibers, a phenotype that was not seen in analogous experiments with ERM proteins. The results demonstrate both similarities and differences between the functional properties of EM10 and ERM proteins expressed in vertebrate cells.

Candida glabrata shuttle vectors suitable for translational fusions to lacZ and use of beta-galactosidase as a reporter of gene expression

The functionality of beta-galactosidase encoded by the E. coli lacZ gene as a reporter of gene expression in C. glabrata was investigated. C. glabrata/E. coli shuttle vectors were constructed, containing both a C. glabrata CEN-ARS cassette, to allow regular segregation and episomal replication of the plasmids, and the lacZ coding sequence of E. coli. The functionality of beta-galactosidase in C. glabrata was verified by inserting the promoter and the 5' coding region of the HIS3 gene from C. glabrata directionally upstream of the lacZ gene. By fusing the promoter of the copper-controlled MTII gene to the lacZ reporter, we showed that beta-galactosidase activity can be differentially induced in C. glabrata. beta-galactosidase reporter activities were detected qualitatively by an indirect filter assay and quantitatively from permeabilized cells.

Distribution of the meningococcal insertion sequence IS1301 in clonal lineages of Neisseria meningitidis

The distribution of the meningococcal insertion sequence IS1301 was analysed in 496 strains of different serogroups and clonal lineages of Neisseria meningitidis, and in 64 neisserial strains other than N. meningitidis. IS1301 was found in meningococci, but not in apathogenic Neisseria sp. and Neisseria gonorrhoeae. The copy numbers of IS1301 varied between 2 and 17 per genome. IS1301 positive strains were mostly found among the serogroups 29E, W135, X, and Y. Clonal lineages of serogroup A, B, and C meningococci associated with epidemic meningococcal disease were rarely positive for IS1301.

The siaA gene involved in capsule polysaccharide biosynthesis of Neisseria meningitidis B codes for N-acylglucosamine-6-phosphate 2-epimerase activity

The capsule polysaccharide of Neisseria meningitidis serogroup B is composed of a homopolymer of alpha-2-->8 linked N-acetyl-neuraminic acid (sialic acid). The enzymes required for sialic acid biosynthesis and polymerization are encoded in region A of the capsule gene complex. We here describe the enzymatic activity of the siaA gene product as determined by biochemical analysis. siaA was overexpressed in Escherichia coli and the SiaA protein was purified to homogeneity. Enzymatic assays revealed that SiaA did not accept N-acetyl-glucosamine as substrate, but only N-acetyl-glucosamine-6-phosphate (EC 5.1.3.9). SiaA catalyzes the isomerization of N-acetyl-glucosamine-6-phosphate to form N-acetyl-mannosamine-6-phosphate. This reaction represents the first step in capsule biosynthesis of N. meningitidis B.

Differential distribution of novel restriction-modification systems in clonal lineages of Neisseria meningitidis

Using representational difference analysis, we isolated novel meningococcal restriction-modification (R-M) systems. NmeBI, which is a homologue of the R-M system HgaI of Pasteurella volantium, was present in meningococci of the ET-5 complex and of lineage III. NmeAI was found in serogroup A, ET-37 complex, and cluster A4 meningococci. NmeDI was harbored by meningococci of the ET-37 complex and of cluster A4, but not by serogroup A meningococci. Two of the R-M systems, NmeBI and NmeDI, were located at homologous positions between the phenylalanyl-tRNA synthetase genes pheS and pheT, which appeared to be a preferential target for the insertion of foreign DNA in meningococci. The distribution of the three R-M systems was tested with 103 meningococcal strains comprising 49 sequence types. The vast majority of the strains had either NmeBI, NmeAI, or both NmeAI and NmeDI. Using cocultivation experiments, we could demonstrate that NmeBI, which was present in ET-5 complex meningococci, was responsible for a partial restriction of DNA transfer from meningococci of the ET-37 complex to meningococci of the ET-5 complex.

Myeloid-related proteins 8 and 14 are specifically secreted during interaction of phagocytes and activated endothelium and are useful markers for monitoring disease activity in pauciarticular-onset juvenile rheumatoid arthritis

OBJECTIVE

To analyze which physiologic stimuli induce secretion of myeloid-related protein 8 (MRP8) and MRP14, two S100 proteins expressed in neutrophils and monocytes, and to determine whether serum concentrations of these proteins are reliable parameters for monitoring inflammatory activity in pauciarticular juvenile rheumatoid arthritis (JRA).

METHODS

Secretion of MRP8 and MRP14 was analyzed using a coculture system of endothelial cells and monocytes. Concentrations of MRP8/MRP14 in the serum and synovial fluid of JRA patients or culture medium were determined by enzyme-linked immunosorbent assay. The expression of MRP8 and MRP14 by leukocytes in synovial tissue or fluid was investigated using immunohistochemistry.

RESULTS

MRP8 and MRP14 were specifically released during interaction of activated monocytes with tumor necrosis factor-stimulated endothelial cells. Secretion was mediated via an increase in intracellular calcium levels in monocytes. In contrast, contact with resting endothelium inhibited protein kinase C-induced secretion of the proteins by monocytes. In JRA patients, MRP8 and MRP14 were strongly expressed in infiltrating neutrophils and monocytes within the inflamed joints and could be found in significantly higher concentrations in synovial fluid (mean 42,800 ng/ml) compared with serum (2,060 ng/ml). Concentrations of MRP8/MRP14 in serum correlated well with those in synovial fluid (r = 0.78) and showed a strong correlation with disease activity (r = 0.62). After intraarticular triamcinolone therapy, the serum concentrations of MRP8/MRP14 decreased significantly in therapy responders, whereas no differences were found in patients who showed no clinical benefit.

CONCLUSION

MRP8 and MRP14 are specifically released during the interaction of monocytes with inflammatory activated endothelium, probably at sites of local inflammation. Their serum concentrations represent a useful marker for monitoring local inflammation in JRA.

Cloning and functional characterization of a 30 kb gene locus required for lipopolysaccharide biosynthesis in Legionella pneumophila

The spontaneous Legionella pneumophila lipopolysaccharide (LPS) mutant 137, which did not bind the LPS-specific mAb 2625, was complemented with a genomic library from the parental wild-type strain. Transformants were screened for reconstitution of the wild-type LPS phenotype, able to bind mAb 2625. By this strategy, a 32,661 bp region comprising 30 open reading frames (Orfs) was identified. Orfs with significant homologies to genes encoding enzymes required for LPS or capsule biosynthesis of Gram-negative bacteria were located on the gene locus. The mutation of strain 137 could be assigned to a deletion of a cytosine residue in Orf 8. The protein encoded by Orf 8 exhibited homology to bacterial methyl-transferases. The L. pneumophila LPS gene locus included genes with deduced products likely to be involved in LPS core oligosaccharide biosynthesis (rmlA-D, rhamnosyl-transferases, acetyl-transferase) as well as LPS O-chain biosynthesis and translocation (mnaA, neuB, neuA, wecA, wzt, wzm). The neuA (Orf 25) and neuB (Orf 24) gene products were functionally characterized by complementation of the capsule negative E. coli K1 mutants EV5 and EV24, respectively. By introduction of the L. pneumophila neuA gene into E. coli EV5 and the neuB gene into EV24, expression of the K1 polysialic acid capsule could be restored. We, therefore, conclude that the biosynthesis pathway of legionaminic acid, the structural unit of the L. pneumophila Sg1 O-antigen, might be similar to the biosynthesis of sialic acid. Southern blot analysis indicated the entire gene locus to be present in L. pneumophila serogroup (Sg)1 strains, whereas only parts of the DNA stretch hybridized to DNA from Sg2 to Sg14 strains.

Expression of myeloid related proteins (MRP) 8 and 14 and the MRP8/14 heterodimer in rheumatoid arthritis synovial membrane

OBJECTIVE

Myeloid related proteins (MRP) 8 and 14 and the heterodimer MRP8/14 are myeloid differentiation markers present on infiltrating tissue macrophages in inflammation but not on resident tissue macrophages. We determined the pattern of expression of MRP8, MRP14, and the MRP8/14 heterodimer (27E10 antigen) in rheumatoid arthritis (RA) synovial membrane (SM).

METHODS

SM samples were obtained from patients with RA at joint replacement surgery or at arthroscopy and patients without joint disease (healthy subjects) and immunostained for MRP8, MRP14, 27E10 antigen (MRP8/14 heterodimer), and CD68. Positive cell staining was measured by quantitative analysis.

RESULTS

SM from 8 patients with RA, including 7 who had paired samples from both adjacent to the cartilage-pannus junction (CPJ) and an area remote from the CPJ, and 2 healthy controls were analyzed. In RA, CD68+ cells accumulated in greater numbers adjacent to the CPJ than remote from the CPJ [mean +/- standard error of the mean (SEM) 488+/-103 and 286+/-76 cells/mm2, respectively; p = 0.01]. SM lining layer (LL) MRP8, MRP14, and 27E10 staining was observed predominantly adjacent to the CPJ and only in patients with active disease. Minimal or absent LL MRP staining was observed in non-CPJ sections. Synovial sublining layer (SL) MRP8, MRP14, and 27E10 staining was also observed only in patients with active disease, but in contrast to the LL, SL staining was observed predominantly in sections remote from the CPJ.

CONCLUSION

MRP antigens, representing activation markers on SM macrophages, were observed predominantly in the LL of sections adjacent to the CPJ samples. These original observations suggest altered activation and differentiation of lining layer macrophages at the site of maximal cartilage destruction in RA.

Endothelial adhesion molecule expression and its inhibition by recombinant bactericidal/permeability-increasing protein are influenced by the capsulation and lipooligosaccharide structure of Neisseria meningitidis

Vascular endothelial injury is responsible for many of the clinical manifestations of severe meningococcal disease. Binding and migration of activated host inflammatory cells is a central process in vascular damage. The expression and function of adhesion molecules regulate interactions between leukocytes and endothelial cells. Little is known about how meningococci directly influence these receptors. In this study we have explored the effect of Neisseria meningitidis on endothelial adhesion molecule expression and found this organism to be a potent inducer of the adhesion molecules CD62E, ICAM-1, and VCAM-1. Exposure of endothelium to a serogroup B strain of Neisseria meningitidis, B1940, and a range of isogenic mutants revealed that lipooligosaccharide (LOS) structure and capsulation influence the expression of adhesion molecules. Following only a brief exposure (15 min) to the bacteria, there were large differences in the capacity of the different mutants to induce vascular cell adhesion molecules, with the unencapsulated and truncated LOS strains being most potent (P < 0.05). Furthermore, the pattern of cell adhesion molecule expression was different with purified endotoxin from that with intact bacteria. Meningococci were more potent stimuli of CD62E expression than was endotoxin, whereas endotoxin was at least as effective as meningococci in inducing ICAM-1 and VCAM-1. The effect of bactericidal/permeability increasing protein (rBPI(21)), an antibacterial molecule with antiendotoxin properties, was also dependent on LOS structure. The strains which possessed a truncated or nonsialylated LOS, whether capsulated or not, were more sensitive to the inhibitory effects of rBPI(21). These findings could have important implications for the use of antiendotoxin therapy in meningococcal disease.

Escherichia coli O157:H7 and O157:H(-) strains that do not produce Shiga toxin: phenotypic and genetic characterization of isolates associated with diarrhea and hemolytic-uremic syndrome

We have isolated one sorbitol-nonfermenting (SNF) Escherichia coli O157:H7 isolate and five sorbitol-fermenting (SF) E. coli O157:H(-) isolates that do not contain Shiga toxin (Stx) genes (stx). Isolates originated from patients with diarrhea (n = 4) and hemolytic-uremic syndrome (HUS) (n = 2). All isolates harbored a chromosomal eae gene encoding gamma-intimin as well as the plasmid genes E-hly and etp. The E. coli O157:H7 isolate was katP and espP positive. Respective sera obtained from the patient with HUS contained antibodies to the O157 lipopolysaccharide antigen. The stx-negative E. coli O157:H7 isolate is genetically related to stx-positive SNF E. coli O157:H7. All stx-negative SF E. coli O157:H(-) isolates belong to the same genetic cluster and are closely related to stx-positive SF E. coli O157:H(-) isolates. Our data indicate that stx-negative E. coli O157:H7/H(-) variants may occur at a low frequency and cannot be recognized by diagnostic methods that target Stx.

An epidemiologic survey of human alveolar echinococcosis in southwestern Germany. Römerstein Study Group

The inhabitants of a rural community in southwestern Germany were examined for alveolar echinococcosis (AE). The study was prompted by the recent increase of the prevalence of the parasite in foxes and the increase of fox populations: in the study area, 75% of the foxes carried Echinococcus multilocularis. The human population was screened using hepatic ultrasound and serology. All participants were interviewed for demographic and potential risk factors. Of 2,560 participants, one was identified with active AE, while 3 others had suspicious liver lesions. Another 9 participants were seropositive for specific antibodies without detectable lesions. Demographic and behavioral factors were not correlated with active or suspected cases nor with seropositivity. If the prevalence of 40/100,000 (95% confidence interval = 15-295/100,000) for active cases would be representative for the rural population in high endemicity areas, the current number of AE cases in southwestern Germany is considerably higher than previously suspected.

The contrasting mechanisms of serum resistance of Neisseria gonorrhoeae and group B Neisseria meningitidis

Neisseria gonorrhoeae and Neisseria meningitidis have evolved intricate mechanisms to evade complement-mediated killing. Sialylation of gonococcal lipooligosaccharide (LOS) results in conversion of previously serum sensitive strains to unstable serum resistance, which is mediated by factor H binding. Porin (Por) is also instrumental in mediating stable serum resistance in gonococci. The 5th loop of certain gonococcal PorlAs binds factor H, which efficiently inactivates C3b to iC3b. Factor H glycan residues may be essential for factor H binding to certain Por1A strains. Por1A strains can also regulate the classical pathway by binding to C4b-binding protein (C4bp) probably via the 1st loop of the Por molecule. Certain serum resistant Por1 B strains can also regulate complement by binding C4bp through a loop other than loop 1. Purified C4b can inhibit binding of C4bp to Por 1B, but not Por1A, suggesting different binding sites on C4bp for the two Por types. Unlike serum resistant gonococci, resistant meningococci have abundant C3b on their surface, which is only partially processed to iC3b. The main mechanism of complement evasion by group B meningococci is inhibition of membrane attack complex (MAC) insertion by their polysaccharide capsule. LOS structure may act in concert with capsule to prevent MAC insertion. Meningococcal strains with Class 3 Por preferentially bind factor H, suggesting Class 3 Por acts as a receptor for factor H.

Eye-hand coordination in uni- and bimanual goal-oriented tasks

Two different drawer tasks were investigated with the aim of assessing the role of eye movements in well-coordinated hand movements. In an unimanual step-tracking task, which had a predictive and an unpredictive movement, a two-way repeated-measures ANOVA showed a significant effect of prediction on the onset of grip-force (GF) rate (300+/-39 ms for the predictive condition versus 394+/-53 ms for the non-predictive condition, P<0.0001). Correlation coefficients, computed from the eye and the hand movements were low for the right and the left hand. The saccade was more coupled with the visual step change than with the action of the hand per se. In a second bimanual pull-and-pick task, the instruction was to pull a drawer with the left hand from a closed position to a LED-cued open position and then to grasp and reinsert a small peg in the drawer with the right hand. Correlation coefficients, computed from the latencies of saccades and of the leading left hand or of the right hand, were significant in four of five subjects. Intermanual correlations were significant in all five subjects. In conclusion, we found that the initial saccade in the unimanual task was best related with the visual step change, but was poorly correlated with the pulling/pushing hand. In the bimanual task, a moderate, but significant temporal coupling between the eyes and hand events was observed. This coupling was, however, less tight than that between both hands.