PubMed Health⌕ Search

Biomedical subjects

T Ziegler

Publications and source records attributed to T Ziegler.

At least 73 records · Page 4Linked to original sources

Pneumonia in childhood: etiology and response to antimicrobial therapy.

A prospective eight-month study was carried out in 50 children admitted to hospital for radiologically confirmed community-acquired pneumonia. A potential causative agent of infection was identified in 44 (88%) cases. Using virus isolation, virus antigen detection and enzyme immunoassay serology, respiratory virus infection was diagnosed in 30 (60%) patients. Antibody assays for seven bacteria and antigen detection from serum and urine for Streptococcus pneumoniae produced evidence of bacterial infection in 31 (62%) cases. Streptococcus pneumoniae (38%), respiratory syncytial virus (30%) and Mycoplasma pneumoniae (20%) were the most common causative agents. A mixed infection was diagnosed in 25 (50%) episodes. Nine patients failed to respond to antibiotics within 24 h after onset of treatment. Three of them had a pure viral infection, three a mixed viral-bacterial infection, two a Mycoplasma pneumoniae infection mixed with other bacteria and one a pure Mycoplasma pneumoniae infection. All three Mycoplasma pneumoniae infections were initially treated with penicillin.

Adolescent↗

Influenza vaccination in the prevention of acute otitis media in children.

We studied a new approach to the prevention of acute otitis media through the administration of influenza vaccine to 187 day-care center children aged 1 to 3 years before the influenza A epidemic of 1988-1989. The control group consisted of 187 unvaccinated children of similar age and background. During the 6-week study period, influenza A infection was diagnosed in five (3%) of 187 vaccinees and in 29 (16%) of 187 controls. Acute otitis media developed in three (60%) of five vaccinees with an influenza A infection compared with 18 (67%) of 27 controls (excluded were two children with a double viral infection). The incidence of acute otitis media associated with influenza A was reduced by 83% in the vaccinees. The total number of children with acute otitis media in the vaccine group was 35, compared with 55 in the control group, disclosing a 36% reduction among the vaccinees. We conclude that influenza vaccination decreases the incidence of acute otitis media in children during an influenza A epidemic, suggesting also that other vaccines against respiratory viruses may be an effective way to reduce the incidence of acute otitis media.

Causality↗

Recurrent wheezy bronchitis and viral respiratory infections.

Fifty four patients aged from 1 to 6 years who had had recurrent attacks of wheezy bronchitis were prospectively followed up for three months to find out if there was an association between different viral respiratory infections and episodes of wheezing. Of the 115 episodes of upper or lower respiratory tract symptoms, virus or Mycoplasma pneumoniae infection were diagnosed in 52 (45%). Thirty four of rhinoviruses. The patients had an average of 2.1 episodes of respiratory tract symptoms the total mean (SD) duration of which was 30 (2) days of the 92 days that followed. Wheezing occurred during 76 (66%) of the 115 episodes and during a third of these the patient was admitted to hospital because of severe dyspnoea. Wheezing started a mean (SD) of 43 (7) hours after the first symptoms of respiratory infection and persisted for 3.8 (4.2) days in patients in whom virus infection was diagnosed. The incidence of wheezing was not associated with IgE mediated atopy, with positive virological tests, or with fever during virus infection, but was associated with parental smoking and more than one sibling.

Bronchitis↗

Synthesis of specifically deoxygenated ligands related to (1----6)-beta-D-galacto-oligosaccharides, and studies on their binding to monoclonal antigalactan antibodies.

Synthetic deoxygenated derivatives of methyl beta-glycosides of (1----6)-beta-D-galacto-oligosaccharides were prepared, and their binding to antigalactan monoclonal antibodies X24 and J539 (Fab') was studied. The results suggest the involvement of an additional, critical hydrogen bond in the highest affinity subsite (A), which now appears to require two hydrogen bonds from the 2- and 3-hydroxyls of the galactosyl residue to the protein, and one from the protein to O-4 of that residue. The data obtained with a series of oligosaccharides deoxygenated at position 3(1), 3(2), 3(3), 4(1), 4(2), or 4(3) support the binding patterns and subsite-arrangement inferred previously from studies with large numbers of deoxyfluoro-substituted ligands and this family of antibodies.

Antibodies, Monoclonal↗

A synthetic heptasaccharide reveals the capability of a monoclonal antibody to read internal epitopes of a polysaccharide antigen.

The binding of the synthetic heptasaccharide,beta-D-Galp-(1----3)-beta-D-Galp-(1----6)-beta-D-Galp-(1 ----6)-beta-D-Galp-(1----6)-beta-D-Galp-1-OCH3 (10) with two monoclonal IgAs of the X24 gene-family has been investigated. The ligand 10 was synthesized by silver triflate mediated coupling of O-(2,3,4,6-tetra-O-benzoyl-beta-D-galactopyranosyl)-(1----3)-O-(2,4,6,-t ri-O-benzoyl-beta-D-galactopyranosyl)-(1----3)-2,4,6-tri-O-benzoyl-alpha -D-galactopyranosyl chloride (5) to the benzoylated, all-beta-(1----6)-linked methyl galactotetraoside 13, having O-6(4) free, followed by debenzoylation of the formed, fully protected methyl galactoheptaoside. The blockwise synthesis of the nucleophile 13 from readily available monosaccharides, and the synthesis of 5 from the corresponding beta-1-O-benzoylated trisaccharide, is also described. Heptasaccharide 10 binds with the (1----6)-beta-D-galactan-specific monoclonal antibodies X-24 and J539 with essentially the same Ka-values (5.4 x 10(5) M-1 and 6.4 x 10(5) M-1, respectively) as does the methyl beta-glycoside of all-beta-(1----6)-linked galactotetraose 14 (5.7 x 10(5) M-1 and 5.9 x 10(5) M-1, respectively). Of the series of homologous oligosaccharides studied previously (di- through a hexa-saccharide), 14 was found to show the highest affinity of interaction with both these immunoglobulins. The beta-(1----3)-linked galactotriose, which forms the bulky terminus of 10, does not appear to bind to these IgA. Thus, the observation that the affinity of 10 is the same as that of 14 confirms that these immunoglobulins bind internal tetrasaccharide sequences of the antigenic (1----6)-beta-D-galactopyranan.

Antibodies, Monoclonal↗

Identification of rhinoviruses by cDNA probes.

We have used nucleic acid hybridization for the detection and grouping of human rhinoviruses (HRV) according to their genetic relationships. Fifteen rhinovirus reference strains, seventy-one clinical isolates and four enteroviruses were propagated in cell cultures, spotted onto membrane filters and hybridized with radioactively labelled cDNA probes covering different parts of the genomes of HRV-1B, HRV-2, HRV-14, HRV-85 and HRV-89. When the rhinovirus and enterovirus reference strains were tested, the 5' probe of HRV-2 hybridized with thirteen of the fifteen HRV reference strains, with poliovirus type 3 and with ECHO virus 11. The HRV-14 5' probe reacted with eleven HRV reference strains and with all the enteroviruses studied. Sixty-nine of the 71 clinical isolates were recognised by the HRV-2 5' probe, whereas the HRV-14 probe from the same part of the genome hybridized with 54 field isolates. One of the two isolates that remained negative with the HRV-2 5' probe was detected with the HRV-2 probe that derived from the P2 region of the genome, and the other isolate was not detected by any of the probes. Probes from other parts than the 5' end of the genome were generally more specific, and clusters could be formed based on the reactivity of the HRV strains with these probes.

DNA Probes↗

Genomic variation of herpes simplex virus type 2 isolates analysed by hybridization after electroblotting from polyacrylamide gels.

Genomic variation of herpes simplex virus type 2 (HSV-2) strains was analysed by polyacrylamide gradient gel electrophoresis and subsequent hybridization to cloned HSV-2 sequences. Two probes were used, one from the L-segment and one from the S-segment of the HSV-2 genome. The probes did not contain a-repeat sequences. Hybridization to the specific sequences in individual DNA fragments obtained by use of the frequently cleaving restriction endonuclease Alu I revealed variations in the genome not detectable by analysing the fragment size only. The use of 35S-labelled deoxynucleotide in the radioactive labelling of the probe further improved the resolution of the method.

DNA, Viral↗

Respiratory virus infection as a cause of prolonged symptoms in acute otitis media.

We studied respiratory viruses in 22 children with acute otitis media who had failed to improve after at least 48 hours of antimicrobial therapy. The mean duration of preenrollment antimicrobial therapy was 4.8 days. For comparison we studied 66 children with newly diagnosed acute otitis media. Respiratory viruses were isolated from middle ear fluid or from the nasopharynx, or both, significantly more often in the patients unresponsive to initial antimicrobial therapy than in the comparison patients (68% vs 41%, p less than 0.05). Viruses were recovered from the middle ear fluid in 32% of the study patients and from 15% of the comparison group. Bacteria were isolated from the middle ear fluid of four (18%) children in the study group; one child had an isolate resistant to initial antimicrobial therapy. All four children with bacteria in the middle ear fluid had evidence of concomitant respiratory virus infection. Our results indicate that respiratory virus infection is often present in patients with acute otitis media unresponsive to initial antimicrobial therapy, and may explain the prolongation of symptoms of infection. Resistant bacteria seem to be a less common cause of failure of the initial treatment.

Acute Disease↗

Rapid detection of respiratory syncytial virus and influenza A virus in cell cultures by immunoperoxidase staining with monoclonal antibodies.

Peroxidase-labeled monoclonal antibodies against respiratory syncytial virus (RSV) and influenza A virus were used for immunoperoxidase staining (IPS) of cell cultures inoculated with nasopharyngeal aspirates. Cells were grown in 24-well plates, and specimens were inoculated by low-speed centrifugation. Cultures were incubated for 2 days at 37 degrees C and then fixed, stained, and observed by light microscopy. IPS was compared with standard virus isolation by using cultures of human diploid fibroblasts and Vero, HEp-2, and HeLa cell lines for RSV and Madin-Darby canine kidney cells for influenza A virus; these cultures were inoculated with specimens that were previously stored at -70 degrees C. Of 40 known RSV-positive specimens, 30 were found to be positive on reinoculation by both methods, and an additional 5 specimens were found to be positive by IPS only. Of 190 specimens tested for influenza A virus, 14 were positive by IPS and in tubes, and a further 8 specimens were positive by IPS only. IPS was also compared with direct detection of viral antigens in nasopharyngeal aspirates by a time-resolved fluoroimmunoassay (TR-FIA). Fresh nasopharyngeal aspirates were inoculated into human diploid fibroblasts and Madin-Darby canine kidney cells and tested for RSV and influenza A virus, respectively, by IPS. Of 110 specimens tested for RSV, 37 were positive in total, 32 were positive by IPS, and 33 were positive by TR-FIA. Of 150 specimens tested for influenza A virus, 39 were positive in total, 35 were positive by IPS, and 34 were positive by TR-FIA. IPS of cultures inoculated by centrifugation and incubated for 2 days is a sensitive method for the diagnosis of respiratory virus infections, and 24-well plates allow for the easy processing of a large number of specimens.

Animals↗

Rhinovirus in otitis media with effusion.

We studied rhinovirus in the middle ear fluid of 61 children with subacute or chronic otitis media with effusion. Rhinovirus was recovered from the middle ear fluid of 5 children with subacute otitis media with effusion. The minimum duration of effusion was 32 to 60 days. Additionally, 1 patient had middle ear fluid that was positive for adenovirus. Bacterial pathogens were cultured from the middle ear fluid of 20 of 61 patients. Our finding that rhinovirus can be isolated from middle ear fluid after an asymptomatic period of several weeks suggests its possible role in the development of otitis media with effusion.

Bacteria↗

Clinical role of respiratory virus infection in acute otitis media.

The clinical characteristics of acute otitis media in relation to coexisting respiratory virus infection were studied in a 1-year prospective study of 363 children with acute otitis media. Respiratory viruses were detected using virus isolation and virus antigen detection in nasopharyngeal specimens of 42% of the patients at the time of diagnosis. Rhinovirus (24%) and respiratory syncytial virus (13%) were the two most common viruses detected. Adenovirus, parainfluenza viruses, and coronavirus OC43 were found less frequently. The mean duration of preceding symptoms was 5.9 days before the diagnosis of acute otitis media. Ninety-four percent of the children had symptoms of upper respiratory tract infection. Fever was reported in 55% and earache in 47% of cases. Patients with respiratory syncytial virus infection had fever, cough, and vomiting significantly more often than patients with rhinovirus infection or virus-negative patients. No significant differences were found in the appearance of the tympanic membrane and outcome of illness between virus-negative and virus-positive patients with acute otitis. Most patients respond well to antimicrobial therapy despite the coexisting viral infection. If the symptoms of infection persist, they can be due to the underlying viral infection, and viral diagnostics preferably with rapid methods may be clinically useful in these patients.

Acute Disease↗

Selective bromoacetylation of alkyl hexopyranosides: a facile preparation of intermediates for the synthesis of (1----6)-linked oligosaccharides.

Bromoacetylation of methyl beta-D-galacto- (1), alpha-D-galacto- (6), beta-D-gluco- (18), (22), and alpha-D-manno-pyranoside (31), and benzyl beta-D-glucopyranoside (27), gave the corresponding 6-O-bromoacetyl derivatives 2, 7, 19, 23, 32, and 28 in 50-60% yields. Bromoacetylation of methyl 3-O-benzyl-beta-D-galactopyranoside (11) afforded methyl 3-O-benzyl-6-O-bromoacetyl-beta-D-galactopyranoside (12, 60%) as well as methyl 3-O-benzyl-2,6-di-O-bromoacetyl-beta-D-galactopyranoside (13, 14%). Compounds 2, 7, 19, 23, 32, 28, and 12 were benzoylated and the fully protected derivatives obtained were dehaloacetylated with thiourea to afford the methyl 2,3,4-tri-O-benzoyl-D-glycopyranosides of beta-galactose (5), alpha-galactose (9), beta-glucose (21), alpha-glucose (25), and alpha-mannose (34), as well as benzyl 2,3,4-tri-O-benzoyl-beta-D-glucopyranoside (30) and methyl 3-O-benzyl-2,4-di-O-benzoyl-beta-D-galactopyranoside (15). These compounds can be used as nucleophiles for the synthesis of (1----6)-linked oligosaccharides. The conversion 1----5 could be performed without isolation of the intermediates. The treatment of bromoacetyl derivatives with benzoyl chloride in pyridine resulted in the benzoylation of the remaining free hydroxyl groups and the simultaneous substitution of bromine by chlorine, yielding the corresponding mono-O-chloroacetyl derivatives. Benzoylations with benzoyl bromide avoided this secondary event. Glycosyl donors differentially substituted to allow further extension of the oligosaccharide chain at position 6 of D-glucose, D-galactose, and D-mannose, and sequentially at positions 6 and 3 in the case of the D-galactosyl donor derived from 15, were readily obtained by treatment of the appropriate, fully protected methyl glycosides with 1,1-dichloromethyl methyl ether in the presence of a catalytic amount of zinc chloride.

Acetylation↗

Pharyngitis in adults: the presence and coexistence of viruses and bacterial organisms.

STUDY OBJECTIVE: To determine the presence and coexistence of viruses and bacterial organisms causing pharyngitis in adults. DESIGN: Open study using diagnostic methods, including rapid antigen-detection techniques, to test for the presence of viruses of the respiratory tract, as well as Mycoplasma pneumoniae. Chlamydia trachomatis, the Chlamydia species strain TWAR, and beta-hemolytic streptococci. SETTING: Open health care. PATIENTS: One hundred six consecutive adult patients, 15 to 65 years old, whose chief complaint was sore throat. MAIN RESULTS: Of the 106 patients, beta-hemolytic streptococci were found in only 24 patients (5 patients with group A streptococci, 13 with group C, 5 with group G, and 1 with group F); M. pneumoniae was found in 10 patients, the Chlamydia species strain TWAR in 9 patients, and viruses in 27 patients. Two microbes were simultaneously isolated in 3 patients, and no microbial findings were detected in 33 patients. CONCLUSION: Because 19 patients were infected with the Chlamydia species strain TWAR and M. pneumoniae, and 24 patients were infected with beta-hemolytic streptococci, the diagnostic procedures and therapies for adult patients with pharyngitis need to be reconsidered. The results of our study also confirm earlier suggestions that the Chlamydia species strain TWAR alone is a causative agent for pharyngitis in adults.

Adolescent↗

Herpes simplex virus detection by macroscopic reading after overnight incubation and immunoperoxidase staining.

Human diploid foreskin fibroblast cells grown in 24-well plates were inoculated with clinical specimens by centrifugation at 1,000 X g for 45 min. Cultures were incubated at 37 degrees C overnight, fixed, and stained with peroxidase-labeled monoclonal antibodies against herpes simplex virus types 1 and 2. Stained plaques of infected cells were large enough to be detected with the naked eye, and microscopic examination did not reveal any further positive specimens. The method was compared with standard isolation in human fibroblasts grown in shell vials and inoculated by centrifugation at 4,000 X g, observed microscopically for the occurrence of typical cytopathogenic effect three times a week for 10 days, and then typed by enzyme immunoassay. Of the 289 specimens tested, 105 were positive and 174 were negative by both methods. Six specimens were positive by standard isolation only, two of them containing varicella-zoster virus, and two specimens were stored frozen before being tested by immunoperoxidase staining. Two specimens found negative by standard isolation were positive by immunoperoxidase staining. For two specimens negative by immunoperoxidase staining, the standard isolation cultures were lost due to microbial contamination. Forty-two specimens found positive by standard isolation were clearly positive when stained only 8 h after inoculation. By standard isolation, positive results were reported on the average 3 to 4 days after inoculation, whereas by immunoperoxidase staining the result was available within less than 24 h. Immunoperoxidase staining of infected cells is a sensitive method for rapid laboratory diagnosis of herpes simplex virus infections, and 24-well plates are convenient for the handling of a large number of specimens.

Antibodies, Monoclonal↗