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Biomedical subjects

P L Andersen

Publications and source records attributed to P L Andersen.

At least 19 recordsLinked to original sources
PubMed2001

Risk of hospitalization for cardiovascular disease after use of macrolides and penicillins: a comparative prospective cohort study.

Chlamydia pneumoniae has been associated with cardiovascular diseases, and C. pneumoniae infection is treatable with macrolides. In this comparative cohort study, 634 users of macrolides and 3827 users of penicillins were identified from the Danish Health Service Registry of Prescriptions and followed up for an average of 6 months. The patients were then linked to the Regional Hospital Discharge Registry to assess the outcome of hospitalization for cardiovascular disease. In the first 3 months, the relative risk (RR) of admission for a cardiovascular disease was 0.48 (95% confidence interval, 0.27-0.88) in users of macrolides compared with users of penicillins. No difference was seen after 3 months. Interaction analyses indicated that the lower risk seen in users of macrolides could be more pronounced in patients without versus those with a previous cardiovascular disease (RR, 0.39 vs. 0.52), in patients >or=60 versus <60 years old (RR, 0.39 vs. 0.64), and in men versus women (RR, 0.35 vs. 0.67).

Aged↗
PubMed2001

The impact of CMV on the respiratory burst of macrophages in response to Pneumocystis carinii.

Infection of human monocyte-derived macrophages with CMV decreased the respiratory burst when cells were stimulated with opsonized zymosan or Pneumocystis carinii (P. carinii). Such an effect, though smaller, was also seen with heat-inactivated CMV, but only when triggered by zymosan. The effect was most pronounced in cells obtained from CMV antibody-negative donors. Dexamethasone further reduced the respiratory burst, both in uninfected and CMV-infected cells. Interferon-gamma increased the response in uninfected cells and, to a lesser extend, in cells treated with heat-inactivated CMV, whereas no effect was seen with infective CMV. No overt productive infection or cytopathology could be detected, however, the monocytes incubated with infective but also heat-inactivated CMV formed clusters, a phenomenon that was equally pronounced in cultures from CMV antibody positive and negative-donors. These results might help explain the worse prognosis of P. carinii pneumonia in patients coinfected with CMV and receiving dexamethasone.

Animals↗
PubMed2001

Antibodies against Chlamydia pneumoniae predict the need for elective surgical intervention on small abdominal aortic aneurysms.

OBJECTIVE: to compare the ability of two independent Chlamydia pneumoniae antibody tests to predict need for small abdominal aortic aneurysm (AAA) repair. PATIENTS AND METHODS: annual scans were offered to 149 screening diagnosed small AAA (<5 cm). Serum samples were collected for measuring IgA and IgG-antibodies to C. pneumoniae by microimmunofluorescence (MIF) test and the new ELISA (Labsystems). RESULTS: a significant concordance was found between MIF and ELISA titres with Kappa values of 0.29 for S-IgA and 0.42 for S-IgG. IgG antibodies measured by ELISA were most predictive for cases expanding operation recommendable sizes with a sensitivity and specificity of 80% and 66%, respectively. CONCLUSION: the simpler EIA has a high correlation with the MIF test and both were predictive for the natural history of AAA. Chlamydia antibody test may be used to identify individuals who might benefit from follow-up and anti-chlamydia treatment.

Aged↗
PubMed2000

[Zoonoses among immigrants].

During the last ten years Denmark has received an increasing number of immigrants, especially from the Balkans, the Middle East, and Somalia. Some of these may suffer from the zoonoses occurring in their country of origin. But apart from echinococcosis, zoonoses in these immigrants do not seem to pose a quantitatively greater problem than in Danes who have visited these areas. However it is important to have a knowledge of the symptoms and mode of transmission of zoonoses occurring in areas where the immigrants come from.

Brucellosis↗
PubMed2000

Divergent regulation of GAP-43 expression and CNS neurite outgrowth by cyclic AMP.

Robust process outgrowth and high expression of the growth-associated protein GAP-43 seem to be intrinsic features of neurons, but both are down-regulated after axonal contact of target cells. We report that chronic exposure of the serotonergic CNS cell line RN46A to cyclic AMP analogs, forskolin, or cholera toxin represses GAP-43 expression in a dose dependent manner. Thus, cAMP could mediate a GAP-43 repressive signal that is initiated extracellularly. Activation of the cyclic AMP pathway by these same reagents, however, enhances the rate that RN46A cells extend neurites. This stimulation of neurite growth can occur during inhibition of new transcription, and in the absence of high levels of GAP-43. These findings demonstrate that a GAP-43-repressing intracellular signaling pathway exists, that repression of GAP-43 expression by cAMP is not directly coupled to inhibition of neurite growth, and that acceleration of growth cone advancement by cAMP is not dependent on the presence of GAP-43.

1-Methyl-3-isobutylxanthine↗
PubMed2000

[Amebiasis].

Amoebiasis caused by the enteric protozoan Entamoeba histolytica is a widespread parasitic disease, which causes 40,000 to 100,000 deaths per year. Cases diagnosed in Denmark are always imported. Infection results from ingestion of amoebic cysts, which after excystation form trophozoits in the small intestine, colonize the bowel lumen and invade the intestinal epithelium resulting in amoebic colitis. Spread to the liver and formation of amoebic liver abscesses occurs in one third of the cases, whereas other extraintestinal manifestations are rare. Amoebic colitis and liver abscess have a good prognosis when treated with metronidazole, whereas complications such as necrotizing colitis, peritonitis and pericarditis have a high mortality. An early diagnosis and treatment is therefore important. Intestinal amoebiasis is diagnosed by demonstration of E. histolytica cysts or amoebae in the stools, whereas serology is of value in diagnosing extraintestinal amoebiasis in nonendemic regions.

Animals↗
PubMed2000

Cyclic AMP prevents an increase in GAP-43 but promotes neurite growth in cultured adult rat dorsal root ganglion neurons.

High expression of the growth-associated protein GAP-43 in neurons is correlated with developmental and regenerative axon growth. It has been postulated that during development and after injury, GAP-43 expression is elevated due to the unavailability of a target-derived repressive signal, but that GAP-43 expression then declines upon target contact. Here we examine the cyclic AMP second messenger signaling pathway to determine if it might mediate retrograde transmission of a signal which represses GAP-43 expression and inhibits growth. Cultures of adult rat dorsal root ganglia were chronically exposed to membrane-permeable analogs of cyclic AMP and activators of adenyl cyclase. These treatments caused GAP-43 protein levels to decrease in a dose-dependent manner, although neuronal survival was not affected. GAP-43 mRNA was also decreases by cyclic AMP. GAP-43 protein levels were not repressed by neurotrophins, cytokines, or other agents. Surprisingly, cyclic AMP caused an increase in the rate of neurite outgrowth, even though the neurons were partially depleted of GAP-43. Growth stimulation was quickly inducible and reversible, could occur in the presence of transcription inhibitors, and did not entail alterations in branching pattern. These findings suggest that axon growth involving high levels of GAP-43 is distinct from the growth stimulation which is rapidly induced by cyclic AMP.

Animals↗
PubMed2000

Chlamydia pneumoniae infection in adults with chronic cough compared with healthy blood donors.

In a small uncontrolled study, persistent cough has recently been found to be associated with serological evidence of acute Chlamydia pneumoniae infection. In order to assess whether C. pneumoniae plays a role in chronic cough, the prevalence of C. pneumoniae infection in 201 adult patients with chronic cough was compared with the prevalence in 106 healthy blood donors without respiratory tract symptoms in the preceding 3 months. A microimmunofluorescence antibody test was used to determine C. pneumoniae antibodies in the immunoglobulin (Ig)M, IgG and IgA fractions. Further, nasopharyngeal aspirates from the 201 patients were examined for C. pneumoniae deoxyribonucleic acid by polymerase chain reaction (PCR). As judged by serology, nine patients (4%) and one control (1%) had acute C. pneumoniae infection, and 92 patients (46%) and 42 controls (40%) had previous or chronic C. pneumoniae infection. Of the nine patients with acute infection, three were C. pneumoniae PCR positive, and they all had an IgM antibody titre response. The remaining six patients had either an IgG antibody titre of > or =512 (five patients) or an IgA antibody titre of > or =512 (one patient). None of these six patients had detectable IgM antibodies. The mean cough period for the five IgG positive patients (10.8 weeks) was significantly longer than the mean cough period for the remaining patient population (6.4 weeks; p=0.004). It is concluded that Chlamydia pneumoniae infection was not statistically significantly more prevalent in patients with chronic cough than in healthy blood donors, and that Chlamydia pneumoniae appears to have a minor role in patients with chronic cough. Direct detection of Chlamydia pneumoniae by polymerase chain reaction on nasopharyngeal aspirates is highly correlated with detectable immunoglobulin M antibodies, but in the late stages of prolonged cough serological testing of immunoglobulin G and immunoglobulin A may be more beneficial for obtaining a microbiological diagnosis.

Adult↗
PubMed2000

Migration of mononuclear cells in the modified Boyden chamber as evaluated by DNA quantification and flow cytometry.

In vitro migration of mononuclear cells in the modified Boyden chamber was evaluated using flow cytometry and DNA quantification (Hoechst 33258) of all adherent and nonadherent cells. The effects of different membrane pore sizes, cell concentrations and incubation times were studied. Pore sizes of 3 and 5 microm resulted in a reduction in the number of nonadherent cells compared with a pore size of 8 microm. Reducing the incubation time from 60 to 40 and 20 min resulted in too few migrating monocytes for analysis by flow cytometry. Flow cytometry showed that both monocytes and lymphocytes migrated and adhered to the membrane when using peripheral blood mononuclear cells (PBMC) to study monocyte migration. Migration of lymphocytes under these conditions is a novel observation. A substantial number of migrated cells could be identified by flow cytometry and quantified by DNA measurement as nonadherent below the membrane. Samples of synovial fluid (n = 49) and plasma (n = 133) as chemoattractants analysed in triplicate resulted in mean coefficient of variation (CV) values of 11 and 9%, respectively. Variation from assay to assay on the same day, using N-formyl-methionyl-leucyl-phenylanine (fMLP) 10(-7) M as chemoattractant resulted in a CV of 13%. Day-to-day variation, using fMLP 10(-7) M as chemoattractant and the same well on three different days, resulted in a CV of 21%. These results were obtained using a pore size of 5 microm, a PBMC concentration of 3 x 10(6)/ml and 60 min of incubation. The combination of DNA quantification and flow cytometry thus allowed characterization and quantification of subsets of migrating adherent as well as nonadherent mononuclear cells.

Antigens, CD↗
PubMed1999

Search for agents causing atypical pneumonia in HIV-positive patients by inhibitor-controlled PCR assays.

Pneumonia is one of the most frequent complications in acquired immunodeficiency syndrome-patients with Pneumocystis carinii as the leading cause. The true prevalence of atypical agents such as Chlamydia pneumoniae, C. trachomatis, Legionella pneumophila and Mycoplasma pneumoniae in this population of patients is unknown as the currently used method for diagnosing these agents is measurement of antibody levels. However, this method is of limited value in human immunodeficiency virus (HIV)-positive patients who may have a compromised antibody response. To evaluate the prevalence of Chlamydia spp., Legionella spp. and M. pneumoniae in HIV-infected patients with pulmonary disease, this retrospective study has applied inhibitor-controlled polymerase chain reaction analyses on 103 bronchoalveolar lavage (BAL) fluids representing 103 episodes of pneumonia in 83 HIV-positive patients. L. pneumophila was detected in 1% of the BAL fluids and M. pneumoniae was found as a coexisting pathogen in 2% of the samples. Chlamydia spp. could not be detected in any of the BAL fluids. By culture and staining methods 106 other microorganisms were detected with P. carinii and Streptococcus pneumoniae as the most frequently occurring. Pneumonia due to Chlamydia pneumoniae, Legionella pneumophila or Mycoplasma pneumoniae seems to be rare in Danish human immunodeficiency virus-infected patients, but might be considered as a possible cause in cases of treatment failure.

Bronchoalveolar Lavage Fluid↗
PubMed1999

Bordetella pertussis and chronic cough in adults.

To evaluate Bordetella pertussis as a cause of persistent cough in adults, we examined 201 patients who had a cough for 2-12 weeks and no pulmonary disease. We obtained the following at presentation: medical history, chest radiograph, respiratory function measurement, nasopharyngeal aspirate for polymerase chain reaction (PCR), nasopharyngeal swab specimen for culture, and a blood sample (acute serum). Four weeks later a second blood sample (convalescent serum) was obtained. Control sera were obtained from 164 age-matched healthy blood donors with no history of cough during the previous 12 weeks. Four patients were B. pertussis culture-positive; 11 (including the culture-positive patients) were B. pertussis PCR-positive; and 33, including 10 of the 11 PCR-positive patients, had serological evidence of recent B. pertussis infection. Pertussis-positive and -negative patients could not be discriminated by a history of cough. We conclude that B. pertussis infection is a common cause of persistent cough in adults. This is of concern, because these patients may be B. pertussis reservoirs from which transmission may occur to infants, in whom the disease can be devastating.

Adolescent↗
PubMed1998

[Castleman's disease--difficult diagnosis].

A case of Mb. Castleman of the localized plasma cell type is reported. This disease expresses several symptoms from different organ systems and therefore an extensive investigation program is often performed. Diagnosis is possible through consideration of all clinical components at the same time: Refractory anaemia, high and refractory SR, weight loss, B-symptoms, but at the same time a relatively good health. CT-scan-demonstration of a localized tumour is an important clue. Histopathologically, the tumour shows vascular hyperproliferation and plasmacytosis of varying maturation. Immunophenotyping of the plasma cells and immunoblasts usually reveals a polyclonal population. Needle biopsies from several regions may be necessary to detect the polyclonality, because monoclonality is often widespread locally in the tumour. HHV8 is correlated to the multicentric PC-type of Mb. Castleman. However, no HHV8 was found in this case.

Adult↗
PubMed1998

Low levels of IgG antibodies against pneumocystis carinii among HIV-infected patients.

IgG antibodies against Pneumocystis carinii (P. carinii) were detected by an ELISA method using urea-extracted material from human and rat P. carinii as the antigen. Carbohydrate formed a major part of the antigen responsible for reactivity in the ELISA assay, since periodate treatment reduced the reactivity of most sera tested. Cross-reactivity between human and rat P. carinii was detected. However, human serum recognized antigens specific for human P. carinii. With the ELISA method IgG antibody levels were compared between blood donors (n = 40), asymptomatic HIV-antibody positive patients (n = 30) and AIDS patients with (n=22) and without previous P. carinii pneumonia (PCP) (n=21). HIV-infected patients had significantly lower antibody reactivity against the microorganism compared with blood donors. Among HIV-antibody positive patients the highest antibody reactivity was seen in PCP patients. The antibody response to PCP was impaired, since an equal number of patients had an increase and a decrease in antibody reactivity. In conclusion, carbohydrate formed an important part of the P. carinii immunogenic antigen. Cross-reactivity between rat and human P. carinii was demonstrated, but reactivity was somewhat lower using antigen from rats. The antibody level was lower in HIV-infected patients and the ability to mount an antibody response to the infection was impaired, suggesting that the poor antibody response may contribute to the liability of HIV-infected patients to have PCP.

AIDS-Related Opportunistic Infections↗
PubMed1998

A randomized controlled trial of acyclovir versus netivudine for treatment of herpes zoster. International Zoster Study Group.

Oral acyclovir has become the standard of care for treatment of acute herpes zoster. Netivudine is a novel antiviral with greater in-vitro activity against varicella zoster virus. It was compared with acyclovir in a randomized, double-blind, controlled trial in immunocompetent adults with herpes zoster. Patients with rash for less than 72 h were assigned to receive either acyclovir or netivudine, then assessed regularly for 6 months. No evidence for a dose response with netivudine was found, so intent-to-treat analyses of all 511 enrolled patients compared acyclovir with netivudine. The time to complete cessation of pain (P = 0.007) and to cessation of moderate to excruciating pain (P = 0.005) was accelerated in acyclovir recipients. Rash outcomes and adverse event profiles were similar for both treatments. This study has confirmed the efficacy of acyclovir in decreasing the duration and severity of pain following herpes zoster. Greater in-vitro activity of newer agents may not necessarily provide greater benefit in humans.

Acyclovir↗
PubMed1998

Viremia in chronic hepatitis C patients evaluated by the Amplicor RT-PCR, a nested RT-PCR, and transaminase levels.

A commercially available kit, Amplicor, was compared with a locally developed nested reverse-transcriptase (RT) PCR for qualitative detection of HCV-RNA. Sixty-one serum samples from sixty-one patients with liver disease, and 60 samples from 60 hemophiliacs without symptoms, but known to have been heavily exposed to hepatitis C virus, were investigated. There was a high degree of concordance between the two diagnostic tests (97%), the Amplicor kit being slightly more sensitive than the in-house PCR, when evaluated using serial dilutions of samples showing discrepant results. The relationship between viremia and abnormal ALT levels was studied in the two groups of patients. Among those with chronic liver disease, 8.3% of patients with viremia had normal ALT levels, whereas transaminases were normal in 20% of hemophiliacs with viremia. This points to ALT as being a poor marker of ongoing viral replication.

Adolescent↗
PubMed1997

[Yellow fever vaccination as prophylaxis of herpes labialis].

At some vaccination centres, it seems to be a clinical observation, that there is a reduction in the number of attacks of herpes labialis following yellow fever vaccination. We therefore conducted a double blind, prospective, randomized study to evaluate the efficacy of yellow fever vaccination against recurrent herpes labialis. Twenty-four patients with culture proven herpes labialis were allocated to either yellow fever vaccination or placebo (saline), with 12 persons in each group. After vaccination/ placebo the patients were followed for one year. The patients returned a letter every other month with information concerning the number of attacks during the period. Comparison of the data from the two groups after one year revealed no significant difference in the number of attacks between the two groups. In conclusion evaluation of the data from this study does not confirm the clinical observation that yellow fever vaccination may act as prophylaxis against herpes labialis.

Adult↗
PubMed1997

Quantitative analysis of GAP-43 expression by neurons in microcultures using cell-ELISA.

A cell-ELISA technique is described which allows the quantification of GAP-43 protein in a large number of microcultures of adult dorsal root ganglion neurons. GAP-43 is measured in the 1-10 ng range, corresponding to the amount of GAP-43 present in fewer than 500 DRG neurons. Specificity of the assay is confirmed using Western blotting and immunocytochemistry. The GAP-43 content of adult DRG microcultures rises during 2 weeks in culture, although the number of surviving neurons decreases. The GAP-43 content of cultured adult DRG neurons is not increased by chronic exposure to added nerve growth factor after 7 days in vitro. However, GAP-43 is increased in DRG taken from animals with prior peripheral nerve injury, and is decreased by chronic exposure to dibutyryl cyclic AMP after 7 days in vitro. The method affords the sensitivity and statistical power to document modest changes in GAP-43 protein abundance in complex cultures.

Animals↗