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Biomedical subjects

J Boman

Publications and source records attributed to J Boman.

At least 37 records · Page 2Linked to original sources

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↗

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↗

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↗

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↗

Small-bowel obstruction secondary to malignant disease: an 11-year audit.

OBJECTIVE: To determine the efficacy and long-term prognosis for operative versus nonoperative treatment of small-bowel obstruction (SBO) secondary to malignant disease. DESIGN: A chart review. SETTING: A university-affiliated teaching hospital. PATIENTS: The medical records of all patients with malignant disease as the established etiology of their obstruction who presented to the Sir Mortimer B. Davis-Jewish General Hospital, Montreal, between 1986 and 1996 were reviewed. There were 32 patients accounting for 74 admissions. INTERVENTIONS: Selective nonoperative management and exploratory laparotomy, immediate or delayed. MAIN OUTCOME MEASURES: The value of nonoperative management and need for operation. RESULTS: Colorectal and ovarian neoplasms were the principal primary malignant diseases that led to SBO. The median time between diagnosis of the malignant disease and SBO was 1.1 years. At their initial presentation, 80% of patients were treated by operation, but 47% of these patients had an initial trial of nonoperative treatment. Reobstruction occurred in 57% of patients who were operated on compared with 72% of patients who were not. The median time to reobstruction was 17 months for patients who underwent operation compared with 2.5 months for patients who did not. Also, 71% of patients were alive and symptom free 30 days after discharge from operative treatment compared with 52% after nonoperative treatment. Postoperative morbidity was 67%. Mortality was 13%, and 94% of patients eventually died from complications of their primary disease. CONCLUSIONS: SBO secondary to malignant disease usually indicates a grim prognosis. Operative treatment has better outcome than nonoperative management in terms of symptom free interval and reobstruction rates. However, it is marked by high postoperative morbidity. We recommend that, after short trial of nasogastric decompression, patients with obstruction secondary to malignant disease be operated on if clinical factors indicate they they will survive the operation.

Adult↗

Chlamydia pneumoniae DNA detection in peripheral blood mononuclear cells is predictive of vascular infection.

Abdominal aortic aneurysm tissue and peripheral blood mononuclear cells (PBMC) of 41 consecutive subjects undergoing abdominal aortic aneurysm surgery were analyzed by polymerase chain reaction (PCR) for the presence of Chlamydia pneumoniae, Mycoplasma pneumoniae, and Helicobacter pylori DNA. Twenty patients (49%) were positive for C. pneumoniae DNA-16 (39%) in both PBMC and aneurysm tissue, 3 (7.3%) in PBMC only, and 1 (2.4%) in the artery specimen only. Previous exposure to C. pneumoniae was confirmed in 19 (95%) of the 20 PCR positive subjects by C. pneumoniae-specific serology, using the microimmunofluorescence test. None was positive for H. pylori or M. pneumoniae DNA, either in the PBMC or in the artery specimens. In conclusion, carriage of C. pneumoniae DNA is common both in PBMC and in abdominal aortic tissue from patients undergoing abdominal aneurysm surgery. Blood PCR may be a useful tool for identifying subjects carrying C. pneumoniae in the vascular wall.

Aged↗

Chlamydia pneumoniae antibodies and high lipoprotein(a) levels do not predict ischemic cerebral infarctions. Results from a nested case-control study in Northern Sweden.

BACKGROUND AND PURPOSE: An association between high lipoprotein(a) [Lp(a)] levels and positive Chlamydia pneumoniae IgG titers in coronary artery disease has been described. The possibility of predicting ischemic stroke by measurements of plasma Lp(a) and C pneumoniae antibodies was investigated. METHODS: This incident case-control study included 101 case subjects (cases) who had suffered ischemic cerebral infarctions and 201 matched control subjects (controls). The study population was nested within the Västerbotten Intervention Program or the WHO MONICA project. Plasma samples were measured for C pneumoniae-specific IgG and IgA antibodies and Lp(a). RESULTS: A significantly higher mean Lp(a) level was found in female cases than in female controls. However, plasma Lp(a) was unable to predict ischemic cerebral infarctions in either women or men. The proportion of individuals with positive C pneumoniae-specific IgG or IgA titers did not differ between cases and controls. Antibody titers were unable to predict a future stroke. The proportion of individuals with a positive C pneumoniae IgG titer in combination with a high Lp(a) level did not differ significantly between cases and controls. CONCLUSIONS: These data suggest that there is no association between baseline plasma Lp(a) levels, presence of C pneumoniae antibodies, and future ischemic cerebral infarctions. Furthermore, no evidence of an interactive effect between high Lp(a) levels and C pneumoniae IgG titers was found. However, selection bias and a recent C pneumoniae epidemic may have influenced the results.

Antibodies, Bacterial↗

[Arteriosclerosis caused by infection? A possible link between Chlamydia pneumoniae and atherosclerosis].

Infection as a possible underlying cause of atherosclerosis has aroused increasing interest in recent years, Chlamydia pneumoniae being one of the organisms upon which attention has been focused. Newly published results of antibiotic treatment of vascular disease not only appear to provide further support for the infection hypothesis, but also suggest a quite different approach to the treatment of atheromatous cardiovascular disease. However, confirmatory clinical trials will be needed before antibiotic treatment can be considered in such cases.

Animals↗

Sero-epidemiological association between human-papillomavirus infection and risk of prostate cancer.

Some epidemiological studies of prostate cancer have suggested the existence of a sexually transmitted risk factor, and some studies have reported the presence of human papillomavirus (HPV) DNA in prostate-cancer tissue. To perform a sero-epidemiological evaluation of whether HPV infection is associated with increased risk for prostate cancer, we performed a nested case-control study within a serum bank containing samples from 20,243 healthy Finnish men. We identified 165 cases of prostate cancer that were diagnosed up to 24 years after donation of the serum sample. Two control subjects per case were selected, matched for gender, age and municipality of residence. Serum samples were analyzed for the presence of IgG antibodies against 4 HPV types and against Chlamydia. The presence of antibodies against HPV type 18 was associated with a 2.6-fold increased risk of developing prostate cancer during follow-up (p < 0.005). HPV type 16 tended to be associated with subsequent prostate-cancer occurrence (relative risk: 2.4, p = 0.06), whereas seropositivity for HPV type 11 or type 33 or for Chlamydia was not associated with risk. The results suggest that infection with oncogenic HPV might be involved in the etiology of a minority of prostate cancers.

Adult↗

Chlamydia pneumoniae in human abdominal aortic aneurysms.

OBJECTIVES: To investigate the presence of Chlamydia pneumoniae DNA in the wall of infrarenal abdominal aortic aneurysms, and in the wall of non-aneurysmal infrarenal abdominal aortas. DESIGN: Case-control study. MATERIALS AND METHODS: The study group consisted of 40 patients operated transperitoneally for an infrarenal abdominal aortic aneurysm (IAAA) (eight females, 32 males; mean age 69 years, median age 68 years). Specimens from the aneurysm wall were taken peroperatively under sterile conditions. The control group consisted of 40 deceased persons without aortic aneurysms (14 females, 26 males; mean age 71 years, median age 70 years). Specimens from the non-aneurysmal infrarenal aortas (NIAA) were collected within 48 h after death. The specimens from both groups were frozen at -70 degrees C immediately after collection. A nested polymerase chain reaction (PCR) method, using two sets of primers designed to detect a fragment of the major outer membrane protein gene of C. pneumoniae, was used. RESULTS: The detection of C. pneumoniae-specific DNA was significantly higher in the study group (14/40 = 35%) than in the control group (2/40 = 5%); (p = 0.001). No clinical factor predicting the presence of C. pneumoniae in the aneurysm wall, could be found. CONCLUSION: Chlamydia pneumoniae was detected at a significantly higher frequency in the wall of IAAAs than in the wall of NIAAs. Although this finding does not prove that C. pneumoniae causes IAAAs, further studies on the possible role of C. pneumoniae in the pathogenesis of aneurysms should be performed.

Aged↗

High prevalence of Chlamydia pneumoniae DNA in peripheral blood mononuclear cells in patients with cardiovascular disease and in middle-aged blood donors.

Nested polymerase chain reaction (nPCR) demonstrated the presence of Chlamydia pneumoniae-specific DNA in peripheral blood mononuclear cells (PBMC). PBMC samples were obtained from 103 consecutive patients (62 male, 41 female) aged 22-85 years (mean, 64) admitted for coronary angiography because of suspected coronary heart disease and from 52 blood donors (43 male, 9 female) aged 40-64 years (mean, 49). Of the 101 evaluable patients, 60 (59%) were identified by nPCR assay as C. pneumoniae DNA carriers; C. pneumoniae-specific microimmunofluorescence (MIF) serology confirmed exposure to the bacterium in 57 (95%) of the 60 nPCR-positive patients. Among the 52 blood donors, the nPCR assay identified 24 (46%) C. pneumoniae DNA carriers, all of whom were positive by C. pneumoniae-specific serology. Thirty-two patients (32%) and 23 blood donors (44%) were MIF antibody-positive but repeatedly nPCR-negative; Bartonella henselae- or Bartonella quintana-specific antibodies were not detected among any of these subjects. In this study, C. pneumoniae DNA was common in PBMC of patients with coronary heart disease and in middle-aged blood donors.

Adult↗

Rapid diagnosis of respiratory Chlamydia pneumoniae infection by nested touchdown polymerase chain reaction compared with culture and antigen detection by EIA.

Chlamydia pneumoniae is a common cause of respiratory tract infection and community-acquired pneumonia. During an extensive outbreak of C. pneumoniae in northern Sweden, 319 respiratory samples from 129 persons were collected. Sputum, throat, and nasopharyngeal samples were obtained and analyzed by nested touchdown polymerase chain reaction (PCR), EIA, and culture in Hep-2 and McCoy cells. Serology was performed by complement fixation and microimmunofluorescence tests. By PCR, 30 patients were diagnosed with C. pneumoniae compared with 26 positive by EIA and 23 by culture. The finding of C. pneumoniae in the respiratory samples was accompanied by serology indicating acute infection in 26 (96%) of 27 patients for whom adequate sera were available. Nested PCR was sensitive and reliable for diagnosing acute respiratory C. pneumoniae infection. Sputum samples had the highest diagnostic efficacy, and the nested type of PCR was superior to one-step PCR. EIA and culture were less sensitive than nested PCR.

Acute Disease↗

Failure to detect Chlamydia trachomatis in cell culture by using a monoclonal antibody directed against the major outer membrane protein.

Two commercially available monoclonal antibodies for cell culture confirmation of Chlamydia trachomatis were compared in two prospective studies and one large retrospective study. In total, more than 33,000 genital specimens were cultured in parallel and stained with both antibodies, one of which was directed against the major outer membrane protein (MOMP) and one of which was directed against the lipopolysaccharide (LPS). We found the anti-LPS-based assay to be more sensitive and as specific as the anti-MOMP-based assay for C. trachomatis cell culture confirmation of genital specimens.

Antibodies, Bacterial↗

Glomerular basement membrane antibodies in hantavirus disease (hemorrhagic fever with renal syndrome).

The prevalence of antibodies against glomerular basement membrane (GBM) antigens in sera from 47 patients with serologically verified hantavirus (Puumala serotype) infection were investigated. Antibodies were measured by immunoassays using as antigen a crude human GBM preparation and the NC1 portion of type IV collagen (Goodpasture antigen), respectively. Seventy-seven percent of the patients had IgM antibodies against the non-Goodpasture glomerular basement membrane (non-GP GBM) in their acute phase serum samples as compared to only 4% seropositivity rate in convalescent phase samples. However, there was no correlation between the non-GP GBM IgM antibody levels and the decrease in GFR as measured by Cr EDTA clearance. None of the patients had antibodies against the Goodpasture antigen. In a control group of 10 patients with influenza and parainfluenza infections serum IgM against non-GP GBM could not be demonstrated, neither in acute phase nor in convalescent phase sera. The possible pathophysiological implications of these findings are discussed.

Adult↗

Low density lipoprotein receptor-related protein-2 expression in efferent duct and epididymal epithelia: evidence in rats for its in vivo role in endocytosis of apolipoprotein J/clusterin.

Apolipoprotein J/clusterin/sulfated glycoprotein-2 (apo J) disassociates from spermatozoa and is endocytosed by epithelial cells lining the efferent ducts and epididymis. The low density lipoprotein receptor-related protein-2/megalin (LRP-2) has been shown to bind to apo J and mediates its endocytosis and lysosomal degradation in cultured cells. In this study, immunocytological techniques were used to localize LRP-2 in rat efferent ducts and epididymis and to determine whether its expression correlated with those epithelial cells involved in apo J endocytosis. Pronounced LRP-2 immunochemical staining was observed on the apical surfaces of epithelial cells lining the efferent ducts and in the intermediate zone, proximal caput, and corpus and cauda regions of the epididymis. Single immunogold labeling at the electron microscopic level showed LRP-2 to be present within coated pits, endocytic vesicles, and early endosomes of the nonciliated cells of the efferent ducts and the principal cells of the epididymis. In efferent ducts, double immunogold labeling showed both LRP-2 and apo J to be present in endocytic compartments including coated pits, endocytic vesicles, and early endosomes of nonciliated cells. However, while apo J was detected in late endosomes and lysosomes of nonciliated cells, LRP-2 was not. Apical tubules, possibly emerging from late endosomes, contained labeling for LRP-2 but not for apo J. Ciliated cells lying adjacent to nonciliated cells displayed no labeling for either LRP-2 or apo J. These results are consistent with the possibility that LRP-2 serves as an endocytic receptor for apo J in vivo and that after endocytosis the LRP-2 is recycled back to the cell surface while apo J is delivered to the lysosomes for degradation. To provide additional evidence implicating LRP-2 in apo J endocytosis, a receptor-associated protein (RAP), an antagonist of apo J binding to LRP-2, was injected into the efferent duct lumen. Subsequent immunocytological analysis of the efferent duct showed that the RAP treatment abolished the endocytosis of apo J by the nonciliated cells. Taken together, these data indicate that LRP-2 is a likely mediator of apo J endocytosis by the nonciliated efferent duct cells.

Animals↗