A novel promoter polymorphism in the gene encoding complement component 5 receptor 1 on chromosome 19q13.3 is not associated with asthma and atopy in three independent populations

BACKGROUND

The inflammatory functions of complement component 5 (C5) are mediated by its receptor, C5R1, which is expressed on bronchial, epithelial, vascular endothelial and smooth muscle cells. A susceptibility locus for murine allergen-induced airway hyper-responsiveness was identified in a region syntenic to human chromosome 19q13, where linkage to asthma has been demonstrated and where the gene encoding C5R1 is localized.

OBJECTIVE

The aim of this study was to screen for novel polymorphisms in the C5R1 gene and to determine whether any identified polymorphisms are associated with asthma and/or atopy and whether they are functional.

METHODS

Single-nucleotide polymorphism (SNP) detection in the gene encoding C5R1 was performed by direct sequencing. Genotyping was performed in three populations characterized for asthma and/or atopy: (1) 823 German children from The Multicenter Allergy Study; (2) 146 individuals from Tangier Island, Virginia, a Caucasian isolate; and (3) asthma case-parent trios selected from 134 families (N=783) in Barbados. Functional studies were performed to evaluate differences between the wild-type and the variant alleles.

RESULTS

We identified a novel SNP in the promoter region of C5R1 at position -245 (T/C). Frequency of the -245C allele was similar in the German (31.5%) and Tangier Island (36.3%) populations, but higher in the Afro-Caribbean population (53.0%; P=0.0039 to <0.0001). We observed no significant associations between the -245 polymorphism and asthma or atopy phenotypes. Upon examination of the functional consequences of the -245T/C polymorphism, we did not observe any change in promoter activity.

CONCLUSION

This new marker may provide a valuable tool to assess the risk for C5a-associated disorders, but it does not appear to be associated with asthma and/or atopy.

Evaluation of a triple-lumen central venous heparin-coated catheter versus a catheter coated with chlorhexidine and silver sulfadiazine in critically ill patients

OBJECTIVE

To compare the incidence of catheter colonization and catheter-related bloodstream infections between heparin-coated catheters and those coated with a synergistic combination of chlorhexidine and silver sulfadiazine.

DESIGN

Randomized, controlled clinical trial.

SETTING

A 20-bed medical-surgical intensive care unit.

PATIENTS

A total of 180 patients requiring the insertion of a trilumen central venous catheter. INTERVENTIONS. Patients were randomized to receive either a trilumen heparin or chlorhexidine and silver sulfadiazine-coated catheter.

MEASUREMENTS

Catheter colonization was defined by a semiquantitative catheter tip culture yielding 15 or more colony-forming units or quantitative culture of 1,000 or more colony-forming units/ml. Catheter-related bloodstream infection as the isolation of the same microorganism from a peripheral blood culture and catheter tip.

RESULTS

A total of 260 catheters were cultured. Out of 132 heparin-coated catheters, 29 were colonized and out of 128 chlorhexidine and silver sulfadiazine-coated catheters, 13 were colonized ( p=0.03), relative risk RR=2.16 (1.18-3.97). This represents an incidence of 23.5 and 11.5 episodes of catheter colonization per 1,000 catheter-days, respectively ( p=0.0059), RR=2.04 (1.05-3.84). Microorganisms isolated in catheter colonization from heparin-coated catheters were gram-positive cocci 23, gram-negative bacilli 7, and Candida spp 4. In chlorhexidine and silver sulfadiazine-coated catheters were gram-positive cocci 6 and gram-negative bacilli 11 ( p=0.009). The incidence of catheter-related bloodstream infections per 1,000 catheter-days was 3.24 in heparin-coated catheters and 2.6 in chlorhexidine and silver sulfadiazine-coated catheters ( p=0.79), RR=1.22 (0.27-5.43).

CONCLUSIONS

In critically ill patients the use of trilumen central venous catheters coated with chlorhexidine and silver sulfadiazine reduced the risk of catheter colonization due to prevention of gram-positive cocci and Candida spp.

Live liver donation: a prospective analysis of exclusion criteria for healthy and potential donors

INTRODUCTION

Living donor liver transplantation represents a controversial option to increase the donor pool.

DESIGN

Prospective and descriptive clinical study.

OBJECTIVE

(1) To identify risk factors (exclusion criteria) for live donation; (2) to determine the rate of recipients that benefit from a living donor.

METHODS

Between May 1995 (first adult-to-adult living donor liver transplantation in Spain) and November 2002, we evaluated 74 healthy volunteers and performed 12 living donor liver transplants (no donor mortality).

RESULTS

All actual donors and volunteers are alive and healthy. After a mean time of 3.2+/-0.5 weeks, 72% of potential donors were considered unsuitable for live donation. Exclusion criteria were grouped in three categories: (primary) donor safety reasons (68%); (secondary): ABO mismatch (17%) and (tertiary): cadaveric graft transplantation (15%). Consequently, just 43.7% of the recipients presenting to us with a potential living donor, did finally benefit from these organs. The mortality rate was 8.3% for 43 recipients presenting with a living donor in comparison to 15% for those who did not (321 recipients between May 1995 and November 2001).

CONCLUSIONS

ALDLT can benefit a significant number of recipients on the waiting list (43.7% of those presenting with a donor). The most frequent exclusion criteria concern donor safety, namely, unsuspected chronic liver diseases and unsuspected thrombophilic disorders.

The challenges of conducting clinical research: one research team's experiences

Conducting clinical research is an exciting and a rewarding endeavor. Each project is unique and, because of this uniqueness, research studies require considerable planning. Regardless of all the upfront planning, challenges will occur throughout the life of the study. Clinical research projects are rife with obstacles that range from the lack of administrative and physician support to subject attrition. Some of the challenges, such as subject dropout, are not unexpected, whereas other unanticipated issues can blindside a research team. This case study examines several such challenges experienced in one longitudinal study and presents the solutions engineered by the research team to keep the project on track.

Presence of granulocytic ehrlichia in ticks and serological evidence of human infection in La Rioja, Spain

In order to estimate the risks of human granulocytic ehrlichiosis (HGE) in an endemic area for Lyme disease in the North of Spain (La Rioja), we collected and investigated by PCR specific to the E. phagocytophila group DNA, a total of 6870 Ixodes ricinus ticks. We also used an indirect immunofluorescence (IFI) test to study the presence of antibodies to the HGE agent in 147 human serum samples including patients with Lyme disease (LD), forestry workers, and persons with history of previous tick bite. Fifty serum samples from healthy people resident in urban areas and with no history of tick-bite disorder and without tick exposure were used as controls. Four of 76 adults and 49 of 203 nymphs pools carried E. phagocytophila DNA. This result, and the finding of 1.4% of sera reacting in the IFI test confirms that this tick-borne agent is present in La Rioja, and that humans show evidence of contact with it. HGE should be considered in the differential diagnosis of flu-like syndromes in the study area in the north of Spain.

Anomalous coronary artery origin associated with bicuspid aortic valve in a patient with rheumatic mitral stenosis: a case report

A rare case of an anomalous left coronary artery arising from the right sinus of Valsalva associated with bicuspid aortic valve is presented. This case is unique because these congenital anomalies were associated with rheumatic mitral stenosis. This anomalous coronary origin was found at catheterization before balloon mitral valvuloplasty. The clinical significance of this finding is discussed.

Molecular cloning and expression patterns of mouse cartilage oligomeric matrix protein gene

OBJECTIVE

To develop transgenic mice harboring mutations in the COMP gene as animal models for pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED), autosomal dominant disorders characterized by early onset osteoarthritis and epiphyseal abnormalities. As a first step in generating a mouse model for COMP mutations, we have cloned the cDNA of mouse COMP and examined its tissue expression pattern.

DESIGN

Total mRNA was isolated from the skeletal tissues of newborn C57BL/6j mice and used as a template for oligo(dT) first-strand cDNA synthesis. The cDNA was used for PCR amplification of COMP using three oligonucleotide primer pairs designed from the published rat COMP cDNA sequence. Nested PCR was used to complete the sequence between the amplified fragments. The entire cDNA was sequenced and the expression pattern of the corresponding transcripts examined by Northern hybridizations.

RESULTS

A full-length COMP cDNA was isolated. Analysis showed that the entire translated region of the mouse COMP gene is 2268 bp and the derived amino acid sequence shows 90% homology to human COMP. Of eight adult mouse non-cartilage tissues tested, COMP expression was detected only in testis.

Pemphigus vulgaris induced by D-penicillamine therapy in a patient with systemic sclerosis

D: -Penicillamine-induced pemphigus occurs infrequently, typically in patients with rheumatoid arthritis. We describe a patient with systemic sclerosis who experienced this complication 3 months after starting D -penicillamine therapy. Nikolsky's sign, histopathologic findings, and direct immunofluorescence all confirmed the diagnosis. Termination of disease progression required intravenous pulse glucocorticoids, azathioprine, and 3 courses of plasmapheresis. The presentation, treatment, and etiology of D -penicillamine-induced pemphigus are reviewed, and the incidence of this complication in scleroderma patients is examined.

Culture of Blomia tropicalis and IgE immunoblot characterization of its allergenicity

Blomia tropicalis is an important triggering factor for allergic diseases such as asthma, rhinitis and atopic dermatitis in tropical and subtropical regions, which climate favours the growth of this species. Our previous mite fauna study revealed that Blomia tropicalis is the most dominant species present in Singapore house dust The main objective of this study is to establish a mass culture of Blomia tropicalis for further characterization of the antigenic and molecular properties of this mite. Approximately one gram of mites could be obtained for every 300-gram of culture medium by culturing under natural condition with a mean annual temperature of 30 degrees C and a mean relative humidity of 80%, and harvested by modified Tullgren funnel. Allergen characterization by IgE immunoblot analysis with crude mite extracts showed some IgE reactivity differences between Blomia tropicalis mite extract from Singapore and Colombia. The possible reasons for these findings are the quality and source of the mite protein extracts used, or selective differences in the population under evaluation. Further, the atopic sera tested showed differences in the pattern and Intensity of IgE immunoblot reactivity to crude extracts of Blomia tropicalis and Dermatophagoides pteronyssinus, the other highly prevalent mite in Singapore. These data support the existence of species-specific allergens. In conclusion, we have been successful in setting up B. tropicalis mass cultures and have prepared extracts of high allergenicity.

A review of the collaborative exercises on DNA typing of the Spanish and Portuguese ISFH Working Group. International Society for Forensic Haemogenetics

Since 1992 the Spanish and Portuguese Working Group (GEP) of the International Society for Forensic Haemogenetics (ISFH) has been organizing collaborative exercises on DNA profiling with the aim of making progress on standardization and discussing technical and statistical problems in DNA analysis. A total of four exercises (GEP-92 to GEP-95) have been carried out until now. A consequence of these exercises was the creation of a quality control programme in Spain and Portugal in 1995 which was carried out simultaneously with the GEP-95 exercise. The number of participating laboratories increased from 10 in the first exercise (GEP-92) to 19 in the last exercise (GEP-95). Despite this increasing number of participating laboratories, results remained satisfactory. In the last exercises, all the laboratories used PCR-based DNA polymorphisms with an increasing number of markers obtaining good results. SLPs were used by only 30% of laboratories in the last two exercises but the results indicated a good level of expertise in most of these laboratories. The reasons for these successful results are the common use of the EDNAP protocol for SLP analysis and commercially available kits or common sequenced allelic ladders for PCR-based DNA polymorphisms.

Cloning and IgE binding of a recombinant allergen from the mite Blomia tropicalis, homologous with fatty acid-binding proteins

To characterize the allergens of Blomia tropicalis, a cDNA library was constructed and screened with allergic sera from asthmatic patients. One clone, Bt6, was subcloned and sequenced. The nucleotide sequence of 934 bp length shows a 390-bp reading frame which encodes a 130-amino acid protein with a MW 14.8 kD. No potential glycosylation site was found in the predicted protein. The inferred amino acid sequence has no homology to known allergens. It has a cytosolic fatty acid-binding protein (FABP) signature at 5-22 amino acid residues, 42.3% identity with the Sm14-FABP of Schistosoma mansoni and 36% identity with FABPs from rat, mouse, bovine and human. The protein was expressed as a GST fusion protein and the purified GST-Bt6 used for dot blot, RAST and RAST inhibition assays. The frequency of IgE binding of allergic sera to Bt6 was low (11%) and usually weak. One positive serum did, however, show strong reactivity by RAST and dot blot and Bt6 could inhibit 60% of the IgE binding of this serum to the B. tropicalis extract. These data show that Bt6 encodes a mite FABP with allergenic properties, which are pronounced in some atopic subjects.

Biochemical evidence of thiamine depletion during the Cuban neuropathy epidemic, 1992-1993

During an epidemic outbreak of neuropathy in Cuba during 1992-1993, blood and urine samples were collected from 107 persons with confirmed neuropathy, from 106 control subjects without clinical abnormality who were broadly matched with the affected persons by age and domicile, and from 537 unmatched subjects, also free from clinical abnormality. The unmatched subjects lived in two locations in Cuba; at each location they were drawn from two age ranges: 11-15-y-old secondary school students and 16-64-y-old adults. Measurements of urinary thiamine and blood transketolase and its activation with thiamine pyrophosphate were made. For the neuropathy subjects, these measurements were repeated after 3 wk of rehabilitation. All groups showed biochemical evidence of thiamine depletion affecting 30-70% of their members, which is a high prevalence. Severity of biochemical depletion was, however, no greater in the neuropathy subjects than in the control subjects (P > 0.05). However, it was greater in Pinar del Rio, where the incidence of disease was higher, than in the city of Havana, where less disease was seen. Although the majority of the affected subjects responded biochemically to a daily oral multivitamin supplement containing thiamine (P < 0.001), in some cases normal biochemical status was not achieved even after 3 wk of intensive treatment. In the affected group, thiamine status was inversely correlated with the amount of alcohol consumed (P = 0.007). Thiamine status at the outset was correlated with clinical outcome after treatment. Although neither thiamine depletion nor alcohol abuse were likely to have been the sole cause of the neuropathy epidemic, they may have been contributory factors. Thiamine supplementation or food fortification may therefore be necessary in Cuba.

The relationship of thoracic lymphadenopathy to pulmonary interstitial disease in diffuse and limited systemic sclerosis: CT findings

OBJECTIVE

Mediastinal lymphadenopathy is frequently associated with interstitial lung disease (ILD) in patients with systemic sclerosis (SSc). This study compared the extent of lymphadenopathy in diffuse and limited SSc with the presence and type of ILD found on CT scans.

SUBJECTS AND METHODS

Seventy-three patients with diffuse and limited SSc underwent thoracic CT. The presence of lymphadenopathy was correlated with the frequency and type of ILD.

RESULTS

Fifty-eight percent (18/31) of patients with diffuse cutaneous SSc and 40% (17/42) of patients with limited cutaneous SSc had lymphadenopathy. A significant relationship was found between lymphadenopathy and the presence of interstitial disease (p = .0002). Seventy-two percent (18/25) of patients with a ground-glass parenchymal pattern of interstitial disease and 74% (14/19) of patients with a honeycomb pattern had lymphadenopathy.

CONCLUSION

Lymphadenopathy is prevalent in patients with SSc and ILD regardless of clinical subtype or interstitial pattern. Lymphadenopathy appears to increase as a function of the profusion rather than the morphology of ILD.

Lung involvement in systemic sclerosis (scleroderma): relation to classification based on extent of skin involvement or autoantibody status

Lung involvement accounts for significant morbidity and is a leading cause of mortality in patients with systemic sclerosis (SSc). It has been shown that different patterns of pulmonary involvement are seen in different subtypes of SSc. This paper reports a retrospective review of 72 patients with SSc to determine whether disease classification according to the extent of skin involvement alone (diffuse vs. limited) or autoantibody status was predictive of pulmonary parenchymal involvement. The diagnosis of interstitial lung disease was based on pulmonary function tests and chest radiographs. Restrictive lung disease was common in both limited SSc (lSSc) and diffuse SSc (dSSc), occurring in 30% and 50% of these patients respectively (P = 0.16). Radiographic evidence of significant interstitial disease was also comparable between the groups [nine of 32 lSSc patients (28%) vs. six of 17 dSSc patients (32%), P = n.s.]. No significant difference in mean lung function was found between patients with anti-Scl 70 antibody (n = 12) compared to those without (n = 60) (TLC 79.0 +/- SE 5.1% predicted vs. 82.8 +/- 2.2, P = n.s.; DLCO 63.0 +/- 5.1 vs. 59.7 +/- 2.5, P = n.s.). By contrast, statistically significant differences in mean lung function were found between patients with anticentromere antibody (ACA) (n = 24) and those without ACA (n = 48) (TLC 98.6 +/- SE 3.9% predicted vs. 79.7 +/- 3.1%, P < 0.001); and less frequent radiographic evidence of severe interstitial disease (0 of 17 with significant interstitial changes on chest radiograph vs. 15 of 32 (47%), P = 0.002). It is concluded that classification of SSc patients on the basis of the distribution of skin involvement poorly predicts the occurrence of interstitial lung disease. On the other hand, ACA is highly associated with the absence of interstitial lung disease.

Autoantibodies in sera from patients with L-tryptophan-associated eosinophilia-myalgia syndrome. Demonstration of unique antigen-antibody specificities

The purpose of this study was to determine whether specific autoantibodies could be identified that are associated with eosinophilia-myalgia syndrome (EMS). Sera from 44 patients with EMS were tested by indirect immunofluorescence, immunodiffusion against calf thymus extract, and immunoprecipitation from HeLa cell extract. Antinuclear antibodies were detected in the sera of 24/39 patients with EMS (61.5%) by indirect immunofluorescence against HEp-2 cells. Seven patients (16%) were demonstrated to have specific autoantibodies by immunoprecipitation in which at least two shared patterns were noted. In three sera immunoprecipitation identified a similar 63-kDa band (Ab-1). An additional four sera shared a pattern of bands consisting of a strong 110-kDa protein and a weak 95-kDa protein (Ab-2). Absorption of HeLa extract with a strongly positive Ab-2 serum confirmed that the four patients shared the same antibody. In conclusion, the detection of these autoantibodies provides evidence of autoimmunity in EMS, and may distinguish this syndrome from clinically related conditions.