Wegener's granulomatosis and parvovirus B19 infection.
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Adolescent↗
Biomedical subjects
J Mertsola
Publications and source records attributed to J Mertsola.
Effects of thermocyclers and primers on the reproducibility of banding patterns in randomly amplified polymorphic DNA analysis.
The effects of thermocyclers and primers on the reproducibility of banding patterns in randomly amplified polymorphic DNA analysis were tested. Purified Bordetella pertussis DNA was analysed with four primers (12-mer), which did not differ from each other in their GC-content. Three different thermocycler models from two manufacturers were tested. Three of the primers produced consistent banding patterns in separate wells of the reaction plates of individual thermocyclers, and in different thermocycler models. In contrast, the fourth primer showed extensive between-instrument variation, and the within-instrument variation with this primer was acceptable only when the most advanced thermocycler model was used. We conclude that only primers that provide consistent banding patterns in different environments should be chosen for interlaboratory use in randomly amplified polymorphic DNA analysis. The primers showing variability in banding patterns can only be used if they produce consistent results in the thermocycler used.
Base Sequence↗
Sensitive and specific polymerase chain reaction assays for detection of Bordetella pertussis in nasopharyngeal specimens.
Polymerase chain reaction (PCR) assays that amplify segments of a repeated gene element and a toxin promoter gene of Bordetella pertussis were compared with a culture established for the diagnosis of pertussis. Of 44 nasopharyngeal (NP) aspirates collected during a pertussis outbreak, repeated gene element PCR showed a positive result in 21 (48%), including all three patients with positive culture results. Results of toxin promoter gene PCR were positive in eight (18%) cases, and the pathogen was not detected in one patient with a positive culture result. A more sensitive nested PCR assay, based on repeated gene element PCR, was then developed. During a second outbreak two different transportation systems were tested in 146 duplicate NP swabs. Transportation of swabs in empty tubes proved to be better than in transport media for PCR. A total of 190 NP specimens from the two outbreaks were tested, and in 56 the results were shown to be positive by PCR, including all 16 cases confirmed as positive by culture. We conclude that the PCR assay is more sensitive than culture in the diagnosis of pertussis; NP swabbing is a simple, practical, and reliable method of collecting clinical specimens for PCR assays and cultures.
Adult↗
Subacute multiple-site osteomyelitis caused by Borrelia burgdorferi.
In a pediatric case of severe multiple-site osteomyelitis caused by Borrelia burgdorferi, the presence of spirochetes in a bone lesion was documented both by culture and by the polymerase chain reaction (PCR). Positive PCR results were also obtained with culture fluid yielding spirochetal growth and with acute-phase serum. Although the disease evidently was a late manifestation of Lyme borreliosis, antibodies to B. burgdorferi were low in titer and were restricted to the IgM class. The distribution of osteomyelitic lesions in multiple bones and the positive PCR results obtained with serum argue for hematogenous spread of the spirochetes. Before the specific diagnosis was established, the patient received several potent antimicrobial drugs, without a favorable outcome. In contrast, therapy with ceftriaxone led to a rapid cure that persisted thereafter. We conclude that infection due to B. burgdorferi must be considered a possible cause of subacute pediatric osteomyelitis.
Bone and Bones↗
Antibodies to filamentous hemagglutinin of Bordetella pertussis and protection against whooping cough in schoolchildren.
A pertussis outbreak was studied prospectively in an elementary school with 39 pupils. All had been immunized with at least three doses of Finnish diphtheria-tetanus toxoid-pertussis vaccine. Diagnosis of pertussis was based on culture, polymerase chain reaction results, and EIA serology using filamentous hemagglutinin (FHA), pertussis toxin, and 69-kDa outer membrane protein as antigens. At the first sampling, 21 children had symptoms suggestive of pertussis, and 18 were healthy. Of the latter, 8 remained healthy without any antibiotic treatment and 9 developed clinical pertussis 1-22 days later. One child developed cough later, but this symptom did not meet criteria for pertussis. The mean levels of IgG, IgM, and IgA antibodies to FHA were significantly higher in 8 healthy children than in 9 children who developed pertussis after the first sampling (P < .001, P = .027, and P = .011, respectively). The results show that antibodies to FHA of Bordetella pertussis in immunized schoolchildren correlate with protection against pertussis.
Adhesins, Bacterial↗
Outcomes of Bordetella pertussis infection in different age groups of an immunized population.
Outcomes of Bordetella pertussis infection were studied in 3 age groups (1-3, 4-6, and 7-15 years) during outbreaks in one day care center (n = 29) and in two elementary schools (n = 210). A total of 76 children were confirmed as having B. pertussis infection; 74 were confirmed by polymerase chain reaction (PCR) and 18 by culture. A positive PCR result was less common in children 1-3 years old than in those 4-6 (P = .006). Asymptomatic B. pertussis infection was more common in preschool children than in schoolchildren (P < .001), whereas schoolchildren presented with symptoms compatible with clinical pertussis more often than preschool children (60/210 vs. 3/29, P = .029). In the community of 12,691, the attack rate (laboratory-confirmed patients/100,000) was 317 in children < 4 years, 1838 in children 4-6 years, 2535 in children 7-15 years, and 248 in persons > 15 years. The protection provided by conventional pertussis vaccine is evidently rather short-lived, and booster vaccinations are needed to eradicate pertussis among schoolchildren and adults.
Age Factors↗
Respiratory syncytial virus infection in children.
Molecular epidemiologic studies have shown that during respiratory syncytial virus (RSV) epidemics several subgroups of viruses cocirculate. On the other hand, very similar strains can be found from widely separated countries at the same time. Nosocomial outbreaks make no exception because multiple sources of virus have also been found within one outbreak. Management of RSV infections has thus far varied largely but based on the recent reports some conclusions can be drawn. Beta-Sympathomimetics have been shown to be of benefit in the treatment of bronchiolitis whereas there is no data to support the use of systemic corticosteroids. Use of ribavirin cannot be recommended in common practice but it seems to have some beneficial effect in the high-risk patients. Mortality risk in the high-risk patients seems to have decreased in latest analyses compared with earlier reports. This has been attributed to improved supportive intensive care management and advances in cardiac surgery. Gammaglobulin has potential both in short-term prophylaxis and treatment of RSV infections. Development of a safe and effective vaccine is one of the main topics in RSV research. Despite some encouraging reports of active prophylaxis, such as use of recombinant fusion protein or temperature-sensitive mutants, we will probably not see a vaccine in clinical practice in the near future.
Child↗
Primers are decisive for sensitivity of PCR.
A sufficient sensitivity of PCR is a prerequisite for its use in the diagnosis of infectious diseases. We have used PCR for detecting gene elements of Borrelia burgdorferi, mycobacteria and Bordetella pertussis. With all these microbe groups, difficulties were encountered in achieving the demanded sensitivity with the primer pairs primarily selected. An extensive testing of various reaction parameters did not improve the sensitivity. Subsequently, we synthesized more primers derived from slightly different positions of the original target sequences. When the original and new primers were tested in possible combinations, some primer pairs reached 100-fold to 1000-fold higher sensitivity than the primary pairs. We conclude that in optimizing the sensitivity of PCR, more emphasis should be put on testing of several primer pairs than on the extensive screening of reaction parameters. Thus far, a trial-and-error approach has to be used, because there is no means to predict the sensitivity properties of a selected primer pair.
Base Sequence↗
Evaluation of pooled and individual components of Bordetella pertussis as antigens in an enzyme immunoassay for diagnosis of pertussis.
Six different antigen preparations for use in an enzyme immunoassay (EIA) to detect IgM, IgA and IgG antibodies to Bordetella pertussis were evaluated using sera from 13 randomly selected culture-positive patients and from 87 patients with suspected pertussis during a pertussis outbreak. Based on results in 80 healthy control sera a specificity limit of 99.9% was selected. Sera from all culture-positive patients reacted with at least one of the antigens. The sensitivity of the EIA using the individual antigen preparations was 85% for filamentous hemagglutinin, 92% for pertussis toxin, 62% for 69 kDa outer membrane protein, 85% for a pool of these three antigens, 54% for sonicated whole bacteria and 69% for 21 kDa pertussis toxin subunit S1. In the outbreak patient group 49 (56%) of the initial sera reacted with at least one of five antigen preparations. The EIA using sonicated bacteria detected only 41% of all seropositive cases compared with 51% using filamentous hemagglutinin, 61% using pertussis toxin, 65% using 69 kDa OMP and 65% using pooled antigen. It is concluded that either the pooled antigen or pertussis toxin antigen are suitable antigen preparations for use in the EIA for diagnosis of pertussis.
Adhesins, Bacterial↗
Detection of enterobacterial lipopolysaccharides and experimental endotoxemia by means of an immunolimulus assay using both serotype-specific and cross-reactive antibodies.
The immunolimulus (IML) assay system uses solid-phase endotoxin antibodies to capture lipopolysaccharide (LPS), which is then quantified by a modification of the chromogenic limulus amebocyte lysate (CLAL) method. Monoclonal antibodies (MAbs) reactive with selected O antigen serotypes of Escherichia coli (O18) and Salmonella typhimurium (O9, 12), when used in the IML, were shown to be highly specific in detecting their respective endotoxins in purified form and in plasma samples from experimentally infected animals. A murine MAb that was broadly cross-reactive with E. coli, Salmonella, and Shigella endotoxins also proved to be highly effective in the IML assay for capturing LPS molecules from both E. coli and S. typhimurium strains. These results indicate that IML assays can detect smooth-type enterobacterial endotoxins in plasma and suggest that such assays have potential for use in the rapid diagnosis of sepsis and endotoxemia caused by different enterobacterial species.
Animals↗
Regional blood flow and oxygen transport in septic shock.
OBJECTIVE: To measure the blood flow distribution and regional oxygen transport in hyperdynamic septic shock during hypotension and after correction by vasopressor doses of dopamine or norepinephrine. DESIGN: Prospective, randomized, controlled trial. SETTING: Tertiary care center. PATIENTS: Ten patients with hyperdynamic septic shock (ages ranging from 45.1 +/- 16.6 yrs) and a control group of 11 postoperative cardiac surgery patients (ages ranging from 54.8 +/- 7.9 yrs). INTERVENTIONS: Systemic and regional hemodynamics and oxygen transport were measured in ten patients with hyperdynamic septic shock during hypotension and after vasopressor therapy (norepinephrine or dopamine). Oxygen consumption (VO2) was measured by indirect calorimetry and splanchnic and leg blood flow with indocyanine green infusion. MEASUREMENTS AND MAIN RESULTS: Splanchnic blood flow and VO2 (p < .05) were increased in septic shock during hypotension and during vasopressor therapy. Both dopamine and norepinephrine increased systemic blood flow and VO2 independently of the arterial lactate level. Despite the relatively small changes in systemic oxygen transport, major regional changes occurred in oxygen delivery and VO2, and these changes were unpredictable from systemic changes. CONCLUSIONS: Regional changes in oxygen transport in septic shock cannot be predicted from the changes in the whole body. The increased oxygen demand in the splanchnic region is the main risk factor for splanchnic tissue hypoxia in septic shock.
Adolescent↗
Comparison of polymerase chain reaction with culture and enzyme immunoassay for diagnosis of pertussis.
A polymerase chain reaction (PCR) assay amplifying a segment of a repeated gene element of Bordetella pertussis was compared with culture and enzyme immunoassay (EIA) for the diagnosis of pertussis. The PCR assay was specific for B. pertussis in tests with a panel of other bacteria and with an extensive collection of specimen material from healthy persons and children with respiratory infections other than pertussis. The PCR assay was used in the analysis of 117 nasopharyngeal swabs collected from children at an elementary school at which a pertussis outbreak occurred. Fifty-six (48%) of the 117 swabs were positive, including those for all six culture-positive cases. The PCR method was then applied to analyze another pertussis outbreak. Of 40 nasopharyngeal aspirates taken from 37 clinically susceptible pertussis patients and from three asymptomatic contacts, the PCR identified 18 (45%), including all 3 culture-positive and 5 (35%) of the 14 seropositive patients. The most consistent and reliable diagnosis by positive PCR result was observed with those patients experiencing symptoms within 1 to 6 weeks of sample collection. We conclude that PCR is a rapid, sensitive, and specific means of diagnosing pertussis, especially during the first weeks of disease. The assay can be performed with both nasopharyngeal swabs and aspirates.
Adolescent↗
Endotoxin concentrations in cerebrospinal fluid correlate with clinical severity and neurologic outcome of Haemophilus influenzae type B meningitis.
Endotoxin concentrations were measured in paired samples of cerebrospinal fluid from 38 patients with Haemophilus influenzae type b meningitis. On admission, the median concentration of endotoxin in cerebrospinal fluid was 104 ng/mL and decreased rapidly in follow-up samples. From 17 to 48 hours after admission, 50% of the patients had concentrations of less than 1 ng/mL. Endotoxin concentrations correlated significantly with concentrations of interleukin 1 beta, protein, and glucose in cerebrospinal fluid, duration of secondary fever, and neurologic abnormalities during hospitalization and on follow-up examinations. Twenty-eight percent of patients with endotoxin concentrations of 100 ng/mL or more on admission had long-term complications, compared with none of those with lower endotoxin concentrations (relative risk, 2.31; 95% confidence interval, 1.53 to 3.48). These results indicate that quantitation of endotoxin in cerebrospinal fluid could be a valuable aid in identifying those children at increased risk of complications during Haemophilus influenzae type b meningitis and provide additional evidence that the Haemophilus influenzae type b meningitis lipo-oligosaccharide is important in the pathogenesis of meningitis.
Animals↗
Cytokines in the pathogenesis of bacterial meningitis.
Adjunctive dexamethasone therapy to antibiotic therapy for bacterial meningitis has been shown in several studies to be beneficial. The roles of interleukin 1 beta and tumour necrosis factor alpha (TNF-alpha) in bacterial meningitis and in an experimental rabbit model are reviewed; both cytokines play a pivotal role in induction of meningitis. Using dexamethasone with the initial dose of antibiotics caused a decrease in TNF-alpha and modulated the inflammatory response. Early use of adjunctive dexamethasone is important in therapy of bacterial meningitis.
Animals↗
Detection of experimental Haemophilus influenzae type b bacteremia and endotoxemia by means of an immunolimulus assay.
The rapid quantitation of bacteria in blood was achieved by using a novel assay method for gram-negative bacterial lipopolysaccharide (endotoxin, LPS). The assay involves the capture of specific LPS onto microtiter plates by means of monoclonal antibodies directed against the oligosaccharide region of the LPS, followed by detection of the bound LPS by a chromogenic Limulus amebocyte lysate (LAL) system. This immunolimulus (IML) assay combines the specificity of monoclonal antibodies with the sensitivity of the LAL system to achieve the first specific, sensitive quantitation of bioactive endotoxin in plasma. In the animal model tested, Haemophilus influenzae type b (Hib) bacteremia in infant rats, there was a strong correlation between IML results and the concentration of Hib colony-forming units in blood samples (r = .845, P less than .001). Using antibodies with appropriate specificities, this approach should be useful for rapid detection of a wide range of gram-negative bacteria and endotoxins in blood.
Animals↗
In vivo and in vitro expression of Haemophilus influenzae type b lipooligosaccharide epitopes.
An indirect immunofluorescence system involving monoclonal antibodies (MAbs) directed against surface epitopes of Haemophilus influenzae type b (Hib) lipooligosaccharide (LOS) was used to examine individual Hib cells in cerebrospinal fluid (CSF) from infants with Hib meningitis. In four of five CSF samples studied, 100% of the bacteria bound at least one LOS-directed MAb. When the bacteria from these CSF samples were grown in broth, most of these cells lost some or all of their ability to bind the MAb(s) that were bound by the same organisms present in human CSF. When in vitro-grown cells were used for intracisternal injection of rabbits, the populations of Hib cells observed in rabbit CSF after the development of meningitis generally resembled those of the respective broth-grown inocula in terms of their LOS antigenic characteristics. Hib cell populations recovered in infant rat CSF after intranasal challenge again had LOS antigenic characteristics similar to those of the in vitro-grown challenge inocula. These results indicate that a population of Hib cells growing in the infected human host may be quite different, with regard to its LOS antigenic characteristics, from the same Hib strain growing in vitro or in vivo in animal models.
Animals↗