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J Boman

Publications and source records attributed to J Boman.

At least 19 recordsLinked to original sources
PubMed2001

Standardizing Chlamydia pneumoniae assays: recommendations from the Centers for Disease Control and Prevention (USA) and the Laboratory Centre for Disease Control (Canada).

Chlamydia pneumoniae has been associated with atherosclerosis and several other chronic diseases, but reports from different laboratories are highly variable and "gold standards" are lacking, which has led to calls for more standardized approaches to diagnostic testing. Using leading researchers in the field, we reviewed the available approaches to serological testing, culture, DNA amplification, and tissue diagnostics to make specific recommendations. With regard to serological testing, only use of microimmunofluorescence is recommended, standardized definitions for "acute infection" and "past exposure" are proposed, and the use of single immunoglobulin (Ig) G titers for determining acute infection and IgA for determining chronic infection are discouraged. Confirmation of a positive culture result requires propagation of the isolate or confirmation by use of polymerase chain reaction (PCR). Four of 18 PCR assays described in published reports met the proposed validation criteria. More consistent use of control antibodies and tissues and improvement in skill at identifying staining artifacts are necessary to avoid false-positive results of immunohistochemical staining. These standards should be applied in future investigations and periodically modified as indicated.

Bacteriological Techniques↗
PubMed2001

Application of blood-based polymerase chain reaction for detection of Chlamydia pneumoniae in acute respiratory tract infections.

The aim of this study was to investigate whether blood-based polymerase chain reaction could serve as a diagnostic tool to identify individuals with acute respiratory Chlamydia pneumoniae infection. Respiratory specimens and peripheral blood mononuclear cells of 58 patients were analyzed using nested polymerase chain reaction and cell culture. Fifteen patients were polymerase chain reaction-positive for Chlamydia pneumoniae. Nine patients were positive in only the respiratory specimen; two in both the respiratory and blood sample (time intervals between onset of symptoms and sample collection, 3-10 days and 3-4 weeks, respectively); and four in only the blood sample. Detection of Chlamydia pneumoniae DNA in peripheral blood mononuclear cells does not seem to be a suitable marker for acute respiratory Chlamydia pneumoniae infection.

Acute Disease↗
PubMed2001

In vitro degradation of aortic elastin by Chlamydia pneumoniae.

OBJECTIVES: to investigate whether Chlamydia pneumoniae (C. pneumoniae) may increase elastin degradation in the aortic wall. MATERIALS AND METHODS: eighteen full thickness aortic wall samples from non-aneurysmal infrarenal abdominal aortas were collected from autopsies. Two adjacent and equally large pieces were cut out of each aortic sample. From each sample, one piece was incubated in a HEp-2 cell culture infected with C. pneumoniae and the other piece was incubated in an uninfected HEp-2 cell culture. The incubation time was one week at 35 degrees C. The concentration of elastin-derived peptides (EDP) (ng/ml) in the medium of each cell culture was measured in duplicate. For each paired sample, delta-EDP (EDP in HEp-2 cell culture infected with C. pneumoniae- EDP in uninfected HEp-2 cell culture) was calculated. RESULT: there was a significantly increased degradation of aortic elastin, estimated by EDP concentrations in cell culture conditioned medium, when aortic wall samples were incubated in C. pneumoniae cultures compared with uninfected cultures (p=0.025, Wilcoxon signed ranks test). CONCLUSION: these results indicate that there is a relationship between the presence of C. pneumoniae and increased elastin degradation in the aortic wall in vitro. This suggests C. pneumoniae in the aortic wall directly or indirectly leads to the degradation of aortic elastin.

Aged↗
PubMed2001

Multicenter comparison trial of DNA extraction methods and PCR assays for detection of Chlamydia pneumoniae in endarterectomy specimens.

The reported rate of detection of Chlamydia pneumoniae DNA within atherosclerotic lesions by PCR varies between 0 and 100%. In this study, identical sets of coded experimental atheroma samples (n = 15) and spiked controls (n = 5) were analyzed by 16 test methods in nine centers by means of PCR. The positive controls were correctly identified to levels of 1, 0.1, and 0.01 inclusion bodies of C. pneumoniae/ml of tissue homogenate by 16 (100%), 11 (69%), and 3 (19%) of the test methods, respectively. Three out of 16 negative controls (19%) were rated positive. Positivity rates for atheroma samples varied between 0 and 60% for the different test methods, with the maximum concordant result for positivity being only 25% for one carotid artery sample. There was no consistent pattern of positive results among the various laboratories, and there was no correlation between the detection rates and the sensitivity of the assay used.

Arteriosclerosis↗
PubMed2000

A preliminary evaluation of a new enzyme immunoassay to detect Chlamydia pneumoniae-specific antibodies.

New enzyme immunoassays (EIAs) for determination of specific IgG, IgA, and IgM antibody titers to Chlamydia pneumoniae were evaluated independently in three research laboratories. Specificity of the EIAs was enhanced by removing LPS from the chlamydial antigen. The performance of these EIAs was evaluated in comparison with the microimmunofluorescence (MIF) test using specimens from: (i) a group of adult patients with community-acquired pneumonia (CAP) previously diagnosed as having an acute chlamydial infection by the complement fixation test or the whole inclusion fluorescence test; (ii) from a group of adult patients with acute respiratory tract infections; and (iii) from a group of young children consecutively presenting with acute respiratory tract infections. The MIF test and the EIAs detected acute infections in paired serum specimens from 12 of 14 patients from the first group. Eleven of these 12 patients were positive in both tests. The MIF test detected seven acute infections in single convalescence serum specimens from eight patients. Two of these were also positive in the EIAs. Paired serum specimens from the second group of adult patients (n=12) were collected during an epidemic of C. pneumoniae. The EIAs detected six acute infections. The MIF test detected two additional patients with acute infections. From the group of young children (n=30), the EIAs detected two patients with acute infections. Our conclusion from this preliminary evaluation is that these EIAs could be useful for laboratory diagnosis of acute C. pneumoniae infections. Comprehensive prospective studies should provide suitable data to calculate the sensitivity, specificity, and predictive values.

Adult↗
PubMed2000

Etiology of small bowel obstruction.

BACKGROUND: Small bowel obstruction (SBO) is a major cause of morbidity and financial expenditure in hospitals around the world. The leading cause of SBO in the western world has become adhesions. The goal of this study was to determine the causes of SBO. METHODS: The medical records of all patients admitted to one hospital between 1986 and 1996 with the diagnosis of SBO were reviewed retrospectively. This included 552 patients accounting for 1,001 admissions. RESULTS: The etiology of SBO was adhesions (74%), Crohn's disease (7%), neoplasia (5%), hernia (2%), radiation (1%), and miscellaneous (11%). Patients with Crohn's disease were younger than patients with other etiologies. Surprisingly, recurrence rates were similar for patients treated operatively as for those treated nonoperatively with the exception in the hernia group where higher recurrence rates were noted for patients initially treated in a nonoperative manner. CONCLUSION: The most common cause of SBO is adhesions followed by Crohn's disease and neoplasia.

Adolescent↗
PubMed2000

Asthma, skin symptoms, and allergy in a condom factory.

BACKGROUND: Cases of occupational asthma have been reported in condom factories in the UK and France, but there has been no epidemiologic study of groups of workers in such factories. This investigation aimed to study the prevalence of symptoms in a Swedish condom factory, to determine groups at special risk, and to suggest preventive measures. METHODS: A questionnaire was mailed to 35 employees, 29 women and six men with mean ages of 37 and 32 years, respectively. All subjects were interviewed by a physician and underwent skin prick test with latex and epicutaneous testing with 39 substances, and blood samples were taken for allergy testing. RESULTS: Phadiatop was positive in 23%, RAST against Lycopodium in 31%, and RAST against latex in one of these 11. Ten subjects (29%) had work-related nose/eye symptoms; of these, eight had positive RAST to Lycopodium; three also had symptoms of occupational asthma and contact urticaria. Only one had positive RAST to latex. Five of the nine subjects with positive Phadiatop also had positive RAST to Lycopodium. All those with RAST positive to Lycopodium had worked in packaging, the area of the factory with the greatest exposure. The results of the patch tests did not correlate with the work-related symptoms. CONCLUSIONS: In a Swedish condom factory, there were a high prevalence of rhinoconjunctivitis and a small number of cases of asthma and contact urticaria caused by allergy to Lycopodium.

Adult↗
PubMed2000

Natural history of patients with adhesive small bowel obstruction.

BACKGROUND: Small bowel obstruction (SBO) is a major cause of morbidity and financial expenditure. The goals of this study were to determine factors predisposing to adhesive SBO, to note the long-term prognosis and recurrence rates for operative and non-operative treatment, to elicit the complication rate of operations and to highlight factors predictive of recurrence. METHODS: The medical records of all patients admitted to one hospital between 1986 and 1996 with the diagnosis of SBO were reviewed retrospectively. This included 410 patients accounting for 675 admissions. RESULTS: The frequency of previous operation by procedure type was colorectal surgery (24 per cent), followed by gynaecological surgery (22 per cent), herniorrhaphy (15 per cent) and appendicectomy (14 per cent). A history of colorectal surgery (odds 2.7) and vertical incisions (odds 2.5) tended to predispose to multiple matted adhesions rather than an obstructive band. At initial admission 36 per cent of patients were treated by means of operation. As the number of admissions increased, the recurrence rate increased while the time interval between admissions decreased. Patients with an adhesive band had a 25 per cent readmission rate, compared with a 49 per cent rate for patients with matted adhesions (P<0.004). At the initial admission 36 per cent of patients were treated surgically. Patients treated without operation had a 34 per cent readmission rate, compared with 32 per cent for those treated surgically (P not significant), a shorter time to readmission (median 0.7 versus 2.0 years; P<0.05), no difference in reoperation rate (14 versus 11 per cent; P not significant) and fewer inpatient days over all admissions (4 versus 12 days; P<0.0001). CONCLUSION: The likelihood of reobstruction increases and the time to reobstruction decreases with increasing number of previous episodes of obstruction. Patients with matted adhesions have a greater recurrence rate than those with band adhesions. Non-operative treatment for adhesions in stable patients results in a shorter hospital stay and similar recurrence and reoperation rates, but a reduced interval to reobstruction when compared with operative treatment.

Humans↗
PubMed2000

The proatherogenic properties of lipoprotein(a) may be enhanced through the formation of circulating immune complexes containing Chlamydia pneumoniae-specific IgG antibodies.

AIMS: To investigate a possible relationship between the atherogenic properties of lipoprotein(a) (Lp(a)) and Chlamydia pneumoniae infections. METHODS AND RESULTS: The study population was nested within the Västerbotten Intervention Program or the WHO MONICA project. In this incident case-control study, 78 patients who had suffered acute myocardial infarction and 156 matched controls were included. The contents of circulating immune complexes were analysed for C. pneumoniae IgG antibodies and Lp(a). A significantly larger proportion of cases than controls had >/=13 mg. l(-1)Lp(a) and a C. pneumoniae specific IgG antibody titre >/=1/2 in circulating immune complexes (odds ratio=3.8). CONCLUSION: The proatherogenic effects of Lp(a) may be enhanced and/or partly mediated through the formation of circulating immune complexes containing C. pneumoniae -specific IgG antibodies. The connection between chronic C. pneumoniae infections and atherosclerosis may, at least in part, be explained by an interaction with Lp(a) through the formation of circulating immune complexes.

Antibodies, Bacterial↗
PubMed2000

Chlamydia pneumoniae serology: interlaboratory variation in microimmunofluorescence assay results.

The lack of standardization in chlamydia serology has made interpretation of published data difficult. This study was initiated to determine the extent of interlaboratory variation of microimmunofluorescence (MIF) test results for the serodiagnosis of Chlamydia pneumoniae infections. Identical panels of 22 sera were sent to 14 laboratories in eight countries for the determination of IgG and IgM antibodies by MIF. Although there was extensive variation in the numeric titer values, the overall percentage agreement with the reference standard titers from the University of Washington was 80%. For results by serodiagnostic category, the best agreement was for four-fold rise in IgG titers, while the lowest agreement was for negative or low IgG titers. Agreement for IgM titers was 50%-95%. Four laboratories failed to discern false-positive IgM titers possibly because of the presence of rheumatoid factor. Further studies are underway to determine the source of interlaboratory variation for the MIF test.

Antibodies, Bacterial↗
PubMed2000

Polymerase chain reaction detection of Chlamydia pneumoniae in circulating white blood cells.

Several recently published studies suggest that Chlamydia pneumoniae may represent a risk factor for atherosclerosis or its complications. In order to establish whether C. pneumoniae is causally linked to atherosclerotic diseases, clinical intervention trials may be needed. However, to identify eligible subjects with a persistent C. pneumoniae infection and to monitor the effect of antibiotic therapy, there is a need for a reliable diagnostic marker. Blood-based polymerase chain reaction assays may be of value for identifying patients persistently infected with C. pneumoniae and for assessing the microbiologic efficacy of antichlamydial therapy in clinical intervention trials.

Animals↗
PubMed2000

Comparison of five serologic tests for diagnosis of acute infections by Chlamydia pneumoniae.

Serology is often used to diagnose acute infections by Chlamydia pneumoniae. In this study paired sera from patients with acute respiratory tract infection during an epidemic of C. pneumoniae infections were examined by five different antibody tests. These tests were the complement fixation (CF) test, the microimmunofluorescence (MIF) test, a recombinant enzyme immunoassay (rEIA) (Medac) based on a recombinant lipopolysaccharide of chlamydia and measuring antibodies to a common chlamydial antigen, and two tests that utilize preparations of C. pneumoniae organisms, the SeroCp-EIA (Savyon) (with preserved lipopolysaccharide) and the LOY-EIA (Labsystems) (without this antigen). Both of the last two tests should measure specific antibodies to C. pneumoniae, although cross-reacting antibodies may also be detected by the SeroCp-EIA. Acute infection of C. pneumoniae was serologically confirmed in 44% of the cases by at least two different tests. Using an expanded "gold standard," i.e., the presence of significant reactions in at least two tests, the sensitivity of the CF test was 69%, that of the MIF test was 88%, that of the rEIA was 89%, that of the LOY-EIA was 96%, and that of the SeroCp-EIA was 92%. Specificity was high for all methods, but adjustments of diagnostic criteria were made to several of the tests. The basis for these adjustments and supportive data are presented. Infections of C. pneumoniae were detected in patients from 8 to 83 years of age. Two peaks in the incidence of such infections were observed: one among young teenagers and a second in adults 30 to 45 years of age, corresponding to parents of young teen-agers. The tests were equally sensitive in different age groups. Reinfections seemed to be rare.

Acute Disease↗
PubMed2000

Is Chlamydia pneumoniae present in brain lesions of patients with multiple sclerosis?

We investigated the presence of Chlamydia pneumoniae in 81 normal and pathological specimens obtained from postmortem brain tissues of patients with multiple sclerosis and with other neurological or nonneurological diseases. The assays used included PCR amplification of all DNA samples in the initial study. Culture and a second PCR amplification of the organism in a subset of 19 brain specimens were also performed in two separate laboratories. All results were negative. Thus, this study on a large number of brain tissues suggests that C. pneumoniae is not involved in inflammatory demyelination.

Brain↗
PubMed2000

Touchdown enzyme time release-PCR for detection and identification of Chlamydia trachomatis, C. pneumoniae, and C. psittaci using the 16S and 16S-23S spacer rRNA genes.

Three touchdown enzyme time release (TETR)-PCR assays were used to amplify different DNA sequences in the variable regions of the 16S and 16S-23S spacer rRNA genes specific for Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci as improved tests for sensitive diagnosis and rapid species differentiation. The TETR-PCR protocol used 60 cycles of amplification, which provided improved analytical sensitivity (0.004 to 0.063 inclusion-forming unit of Chlamydia species per PCR). The sensitivity of TETR-PCR with primer set CTR 70-CTR 71 was 96.7%, and the specificity was 99.6%, compared to those of the AMPLICOR PCR for the detection of C. trachomatis in vaginal swab samples. TETR-PCR for C. pneumoniae with primer set CPN 90-CPN 91 was 90% sensitive and 93.3% specific compared with a nested PCR with primer set CP1/2-CPC/D for clinical respiratory samples. TETR-PCR for C. psittaci with primer set CPS 100-CPS 101 showed substantial agreement with cell culturing (kappa, 0.78) for animal tissue samples. Primer sets were then combined into a single multiplex TETR-PCR test. The respective 315-, 195-, and 111-bp DNA target products were precisely amplified when DNA from each of the respective Chlamydia species or combinations of them was used. Multiplex chlamydia TETR-PCR correctly identified one strain of each of the 15 serovars of C. trachomatis, 22 isolates of C. pneumoniae, and 20 isolates of C. psittaci. The primer sets were specific for each species. No target products were amplified when DNA from C. pecorum or a variety of other microorganisms was tested for specificity. TETR-PCR with primers selected for specific sequences in the 16S and 16S-23S spacer rRNA genes is a valuable test that could be used either with individual primers or in a multiplex assay for the identification and differentiation of Chlamydia species from culture isolates or for the detection of chlamydiae in clinical samples.

Base Sequence↗