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W Bossart

Publications and source records attributed to W Bossart.

At least 19 recordsLinked to original sources
PubMed2006

[Povidone-iodine for treatment of adenoviral conjunctivitis: an in vitro study].

BACKGROUND: Adenoviral conjunctivitis causes high socioeconomic costs due to high contagiousness and therefore the need for extended quarantine. To date the only potentially active, topical antiviral agent is povidone-iodine (PVI). The aim of this study was to investigate the effect of diluted PVI on free adenovirus and adenoviral infected cells as well as to evaluate the cellular toxicity of PVI on non-infected cells. MATERIAL AND METHODS: PVI was diluted to a final concentration of 0.0008 %. Virucidal activity was measured IN VITRO using adenovirus 8 and A549 human epithelial cell cultures. Cytotoxicity effects on healthy cells after short- and long-term exposure to diluted PVI were measured in A549 cell cultures. RESULTS: Exposure to PVI at a concentration of 1:10 (0.8 %) completely extinguishes infectivity of free adenovirus after an exposure time of 10 minutes. PVI is less effective against intracellular adenovirus resulting in a decreased infectivity and viral activity for approximately one day with a narrow spectrum between toxicity and virucidal activity. Healthy epithelial cells can be exposed to PVI for up to 6 hours without a cytotoxic effect. CONCLUSIONS: PVI is highly effective against free adenovirus but less effective against intracellular adenoviral particles in already infected cell. Short- and long-term exposure of PVI causes little cytotoxicity for healthy cells. Therefore, administration of diluted PVI at a concentration of 1:10 is a potential option to reduce contagiousness in cases of adenoviral infections.

Adenoviridae↗
PubMed2003

[Fever after a tick bite: clinical manifestations and diagnosis of acute tick bite-associated infections in northeastern Switzerland].

BACKGROUND: Different tick-borne infections can cause an acute febrile illness. The study objectives were to investigate the clinical manifestations and diagnosis of infections among patients who presented with fever after a tick-bite, and to detect newly described pathogens, including Ehrlichia, Babesia and Rickettsia helvetica, in North-Eastern Switzerland. PATIENTS AND METHODS: : We studied 75 patients (41 male, 34 female, median age 38 years, among them 10 children) who had fever within 3 weeks after a tick-bite. Paired sera were tested for antibodies to Borrelia burgdorferi, tick-borne encephalitis virus, Anaplasma (Ehrlichia) phagocytophila, Babesia microti, B. divergens, and Rickettsia helvetica. In addition, microscopy and polymerase chain reaction was used to detect Ehrlichia. Clinical data were obtained at baseline and at 1 and 2 year follow-up. RESULTS: Tick-borne infections were confirmed or possible in 36 (48 %) patients: 7 (9 %) Erythema migrans, 6 (8 %) other specific manifestations of Lyme borreliosis, 6 (8 %) Lyme borreliosis presenting as non-specific febrile illness, 8 (11 %) tick-borne encephalitis, 7 (10 %) granulocytic ehrlichiosis, 1 B. microti infection in a traveler from the US and 6 (8 %) dual infections. In 8 (11 %) patients serological findings were suggesting possible acute or past R. helvetica infection. CONCLUSION: Among patients with fever after a tick-bite, Lyme borreliosis was most frequently found. There was no evidence for babesiosis among the resident population. Serologic data suggest that human granulocytic ehrlichiosis and R. helvetica infections may be endemic in Switzerland. Among 50 % of the patients no tick-borne infections could be diagnosed.

Acute Disease↗
PubMed2001

Polyclonal proliferation of large granular lymphocytes during cytomegalovirus primary infection in a human immunodeficiency virus-infected patient receiving antiretroviral therapy.

We report the first case of a patient infected with HIV in whom polyclonal CD8+/CD57- T lymphocyte large granular lymphocyte (LGL) proliferation was observed in association with cytomegalovirus primary infection. Because the differential diagnosis of an increased number of LGLs includes both monoclonal LGL leukemia and polyclonal proliferation of LGL, patients in whom LGL proliferation is detected always need close hematological and clinical observation to determine whether therapeutic intervention is necessary.

AIDS-Related Opportunistic Infections↗
PubMed2001

Phase I clinical trial with HIV-1 gp160 plasmid vaccine in HIV-1-infected asymptomatic subjects.

The aim of the study was to investigate the safety of an HIV-1 gp160 plasmid vaccine. Four asymptomatic HIV-1-infected subjects with CD4+ lymphocyte counts >500/microl were injected with four times 400 microg of HIV-1 modified gp160 env and rev coding DNA vaccine at 0, 4, 10 and 28 weeks. Safety parameters, including autoimmune antibodies as well as CD4+/CD8+ cell counts and HIV-1 plasma concentrations, were monitored for 52 weeks after the first vaccine application. Follow-up data for more than 3 years are now available. The DNA vaccine proved to be safe and, specifically, did not induce anti-DNA autoimmune antibodies. Vaccination had no long-term effects on the CD4+/CD8+ lymphocyte counts, plasma HIV-1 RNA concentrations or disease progression. The present data supplement published data from Philadelphia, USA, where a dose-escalating study (30-300 microg) with the same HIV-1 DNA vaccine was performed.

AIDS Vaccines↗
PubMed2001

Community-acquired pneumonia in children due to Mycoplasma pneumoniae: diagnostic performance of a seminested 16S rDNA-PCR.

A 16S rDNA-PCR assay for Mycoplasma pneumoniae applied to nasopharyngeal secretion (NPS) or pharyngeal swab (PS) from children with community-acquired pneumonia (CAP) was prospectively compared to serological tests including complement fixation (CF) test, a mu-capture enzyme immuno assay (EIA) for the detection of specific IgM, and an EIA for the detection of specific IgG. During a 24-months-period diagnosis of active M. pneumoniae infection was established in 32 (12.6%) of 253 patients for whom paired sera were available. In the acute phase, the sensitivities of PCR from NPS and PS, CF test, IgM EIA, and IgG EIA were 90.0%, 79.3%, 46.9%, 78.1%, and 59.4%, respectively. The corresponding specificities were 98.1%, 98.6%, 97.6%, 87.1%, and 72.4%, respectively. Thus, the 16S rDNA-PCR assay provides a highly sensitive and accurate tool for the rapid diagnosis of M. pneumoniae infection in children with CAP.

Adolescent↗
PubMed2001

Reliable detection of respiratory syncytial virus infection in children for adequate hospital infection control management.

By using a rapid test for respiratory syncytial virus (RSV) detection (Abbott TestPack RSV), a number of patients were observed, showing repeatedly positive results over a period of up to 10 weeks. A prospective study was initiated to compare the rapid test with an antigen capture enzyme immunoassay (EIA) and a nested reverse transcriptase PCR (RT-PCR) protocol for detection of RSV serotypes A and B. Only respiratory samples from children exhibiting the prolonged presence of RSV (> or =5 days) as determined by the rapid test were considered. A total of 134 specimens from 24 children was investigated by antigen capture EIA and nested RT-PCR. Using RT-PCR as the reference method, we determined the RSV rapid test to have a specificity of 63% and a sensitivity of 66% and the antigen capture EIA to have a specificity of 96% and a sensitivity of 69% for acute-phase samples and the homologous virus serotype A. In 7 (29%) of 24 patients, the positive results of the RSV rapid test could not be confirmed by either nested RT-PCR or antigen capture EIA. In these seven patients a variety of other respiratory viruses were detected. For general screening the RSV rapid test was found to be a reasonable tool to get quick results. However, its lack of specificity in some patients requires confirmation by additional tests to rule out false-positive results and/or detection of other respiratory viruses.

Adolescent↗
PubMed2001

Dynamics of Epstein-Barr virus DNA levels in serum during EBV-associated disease.

A real-time polymerase chain reaction assay for quantitation of Epstein-Barr virus (EBV) DNA in serum was developed. This assay detected EBV DNA in 24 (89%) of 27 sera from patients with infectious mononucleosis, but only in 9 (18%) of 51 sera from EBV carriers (P < 0.001) and in none of the sera from 32 EBV-seronegative individuals. EBV DNA levels were higher in sera from infectious mononucleosis (median 8,000, range 1833-150,069 copies/ml) than from carriers (median < 2, range < 2-2980; P < 0.001). In sera of 36 children with infectious mononucleosis followed prospectively, EBV DNA levels correlated inversely with the duration of symptoms. Among 18 children with tumors including Hodgkin's disease (n = 7), non-Hodgkin's lymphoma (n = 6), Burkitt's lymphoma (n = 1), lymphoproliferative disorder (n = 4), and osteosarcoma (n = 1), EBV DNA was detected in serum from those 9 (100%) expressing EBV in the tumor (Hodgkin's disease, 3; non-Hodgkin's lymphoma, 2; lymphoproliferative disorder, 4), the levels peaking at diagnosis and correlating with disease activity. Quantitation of EBV DNA in serum may offer a simple means of monitoring patients at risk of EBV-associated lymphoproliferation.

Bone Neoplasms↗
PubMed2000

[Diagnosis and course of myocarditis: a survey in the medical clinics of Zurich University Hospital 1980 to 1998].

The clinical picture of myocarditis/myopericarditis is of importance in differential diagnosis, especially in younger patients with suspected myocardial infarction. Myocarditis/myopericarditis commonly presents with chest pain, and the diagnosis is usually established on clinical grounds. However, endomyocardial biopsy is necessary to confirm the diagnosis. We evaluated the characteristics of acute myocarditis over the years 1980-1998 in 54 patients of the Department of Medicine of the University Hospital, Zurich. Two to 6 patients per year were hospitalised with this diagnosis. In most cases the diagnosis was established by a combination of criteria, such as a preceding infection of the upper respiratory tract, thoracic pain, ST segment elevations in different precordial leads followed by T wave inversions, arrhythmias, elevation of cardiac enzymes, reversible hypokinesia by echocardiography and normal coronary arteries. At least 3 of 5 criteria were requested. In a first step we analysed retrospectively all patients with acute myocarditis/myopericarditis in the years 1980-1993. Among 30 cases of acute myocarditis/myopericarditis the following causes could be identified: one influenza B, one Toxoplasma gondii infection, 2 Epstein-Barr infections and one bacterial myocarditis with gram-negative rods. The aetiology of the other 25 cases remained unknown. The majority of myocarditis/myopericarditis healed without complications. One patient with Epstein-Barr myocarditis and one with Toxoplasma gondii infection died. Two patients developed dilated cardiomyopathy. In a second phase we analysed prospectively all cases with acute myocarditis/myopericarditis over the period 1994-1998: 24 patients with acute myocarditis/myopericarditis were hospitalised. At that time coronary angiography and endomyocardial biopsies were performed more frequently. We found 2 patients with giant cell myocarditis and 2 with Toxoplasma gondii infection and HIV, all of whom died. In addition, there were 2 patients with eosinophilic myocarditis, one with Lyme carditis, one with Epstein-Barr myocarditis, one with myopericarditis after Campylobacter enteritis and one histologically proven myocarditis after pneumonia with Haemophilus influenzae. The aetiology of the remaining 13 cases with myocarditis/myopericarditis could not be established. Three patients with probable viral myocarditis developed cardiogenic shock requiring intraaortic balloon pump, and fully recovered. The patient with Lyme carditis manifested with total atrioventricular block and was treated with a temporary pacemaker. One patient with lymphocytic myocarditis required heart transplantation because of terminal heart failure and one female patient with histologically proven diffuse lympho-monocytic myocarditis died of cardiogenic shock. All the other cases healed without complications. Serologies are of little diagnostic value and should be restricted to serologies with therapeutic implications. We believe that the apparent increase in myocarditis/myopericarditis in recent years is a result of better diagnostic tools, such as more specific cardiac enzyme tests, coronary angiography and endomyocardial biopsies. In most cases the therapy remains symptomatic. In elected, severe cases steroids and other immunosuppressive drugs are sometimes used.

Acute Disease↗
PubMed2000

Rapid detection of Mycoplasma pneumoniae in clinical samples by real-time PCR.

M. pneumoniae is a common causative agent of community-acquired pneumonia in children. The diagnosis of such infections is usually based on serology using complement fixation or, more recently, enzyme-immuno assays. PCR has been shown to be a promising alternative. We have evaluated a real-time PCR assay targeting the P1 adhesion protein gene and compared it to a conventional semi-nested PCR assay with the 16S rDNA as target. Comparison of 147 specimens from 48 patients showed an overall agreement of 97.4%. Real-time PCR proved to be of equal value on clinical specimens as conventional PCR regarding sensitivity and specificity, but is clearly advantageous regarding speed, handling and number of samples that can be analyzed per run.

Adolescent↗
PubMed1999

Two-centre study comparing DNA preparation and PCR amplification protocols for herpes simplex virus detection in cerebrospinal fluids of patients with suspected herpes simplex encephalitis.

In a two-centre study, the routine DNA preparation and PCR amplification protocols were compared for herpes simplex virus (HSV) detection in cerebrospinal fluids (CSFs) of 43 patients with suspected herpes simplex encephalitis (HSE). The combined clinical, radiological and laboratory results indicated HSE in 6/43 (14%) patients. Discrepant PCR results between the two centres were obtained in 8 (18%) cases consisting of 5 false-positive and 3 false-negative results. Seven out of 8 (88%) discrepant results were associated with the method of CSF preparation using protease K digestion followed by heat inactivation. In contrast, CSF digestion with proteinase K followed by DNA purification on silica spin columns was better yielding discrepant PCR results in only 1 of 78 analyses (1.3%). The results point to the need for standardization and inter-laboratory quality control for routine clinical work.

DNA, Viral↗
PubMed1999

Detection and quantification of cell-free Epstein-Barr virus by polymerase chain reaction and subsequent DNA enzyme immunoassay.

Amplification by polymerase chain reaction and subsequent DNA enzyme immunoassay (DEIA) were employed to determine the number of genome equivalents of cell-free Epstein Barr virus (EBV) DNA in peripheral blood. The assay detected cell-free EBV DNA in the serum of 14 out of 18 patients with primary, productive EBV infection (sensitivity 77.7%) but not in healthy EBV carriers with latent infection (specificity 100%). Our assay has the potential for a clinical diagnostic tool to monitor patients at risk for EBV reactivation and productive infection with subsequent EBV-induced lymphoproliferative diseases.

Base Sequence↗
PubMed1998

[Clinical evaluation of impression cytology in diagnosis of superficial viral infections].

BACKGROUND: Impression cytology is a non invasive technique for the diagnosis of external eye disease. As infected epithelial cells are losing their adhesion to neighbouring cells they are an ideal target for impression cytology. Despite its diagnostic potential impression cytology has not yet become a routine diagnostic tool because of technical inconvenience in use of conventional membranes. The aim of this study was to evaluate a practicable technique of impression cytology for the rapid diagnosis of superficial viral eye disease. MATERIAL AND METHODS: 52 patients with suspected viral conjunctivitis or keratitis underwent impression cytology with a Biopore membrane device. After air fixation immunologic detection tests using either peroxidase antiperoxidase or fluorescent techniques were performed directly on the membrane. RESULTS AND CONCLUSIONS: 21 of 38 patients with suspected Herpes-simplex-virus (HSV), 3 of 4 patients with suspected Varicella-Zoster-virus (VZV) and 2 of 10 patients with suspected Adenovirus infection had a positive result on the impression cytology membrane. These results were confirmed by virus cultures or polymerase chain reactions (PCR) a few days later. No patient with a negative impression cytology had a positive culture result. Using impression cytology and an immunodetection test results became available within 1 to 4 hours. CONCLUSIONS: Impression cytology combined with immunologic detection tests is a rapid, sensitive and practicable diagnostic test for superficial viral eye diseases.

Adenovirus Infections, Human↗
PubMed1997

Surveillance of cytomegalovirus after solid-organ transplantation: comparison of pp65 antigenemia assay with a quantitative DNA hybridization assay.

In a multicenter study, 113 blood samples from 19 organ transplant patients were analyzed for cytomegalovirus by the pp65 antigenemia assay and a quantitative DNA hybridization assay. Overall, there was 84% agreement among the results obtained by the two tests. Fifteen of 16 episodes of active infection were detected by both assays. One episode was missed by the pp65 assay, and one patient showed significant DNA-emia but only low-level antigenemia.

Antigens, Viral↗
PubMed1997

Improved impression cytology techniques for the immunopathological diagnosis of superficial viral infections.

BACKGROUND: For epidemiological and therapeutic reasons early diagnosis of superficial viral infections is crucial. Conventional microbiological techniques are expensive, time consuming, and not sufficiently sensitive. In this study impression cytology techniques were evaluated to analyse their diagnostic potential in viral infections of the ocular surface. METHOD: A Biopore membrane device instead of the original impression cytology technique was used to allow better quality and handling of the specimens. The impressions were processed, using monoclonal antibodies and immunoperoxidase or immunofluorescence techniques to assess the presence of herpes simplex virus, varicella zoster virus, or adenovirus antigens. Ocular surface specimens from healthy individuals (n = 10) and from patients with suspected viral surface disease (n = 19) were studied. Infected and non-infected cell cultures served as controls. RESULTS: This modified technique of impression cytology allowed the collection of large conjunctival and corneal epithelial cell layers with excellent morphology. Immunocytological staining of these samples provided diagnostic results for all three viruses in patients with viral surface disease. CONCLUSIONS: The use of Biopore membrane devices for the collection of ocular surface epithelia offers new diagnostic possibilities for external eye diseases. Immunopathological methods that are applied directly on these membrane devices can provide virological results within 1-4 hours. This contributes considerably to the clinical management of patients with infectious diseases of the ocular surface.

Antigens, Viral↗
PubMed1996

[Fever and headache].

A 30-year-old male patient was admitted to our outpatient clinic because of fever, headache and cerebellar symptoms. Clinically he presented with a slight meningism. After exclusion of a focal intracerebral process by head scanning, a first diagnosis of an aseptic meningitis was made by the analysis of the cerebrospinal fluid. With the hint of repeated tick bites, the diagnosis of an early-summer meningoencephalitis was confirmed. The patient recovered without neurological residua within two months. The clinical course, dates of new epidemiologic studies and problems of vaccination are discussed.

Adult↗
PubMed1996

Severe tick-borne encephalitis following passive immunization.

UNLABELLED: We report on a 5-year-old girl with an unusually severe course of tick-borne encephalitis following passive immunization with specific hyperimmune globulin after a tick bite in an endemic area. Serial investigations of the CSF revealed intrathecal production of specific antibodies paralleled by increasing numbers of B-cells after initial T-cell pleocytosis. Focal central lesions were evident on MRI. CONCLUSION: The severity of the presented case questions the benefit of passive immunization and rather justifies consideration of vaccine recommendation to residents and travellers to areas endemic for tick-borne encephalitis virus.

Child, Preschool↗