Search PubMed⌕ Search

Biomedical subjects

L E Fenelon

Publications and source records attributed to L E Fenelon.

15 recordsLinked to original sources

Production of specific monoclonal antibodies to Aspergillus species and their use in immunohistochemical identification of aspergillosis.

Two anti-Aspergillus murine monoclonal antibodies (MAbs), designated 164G and 611F, have been produced; both specifically recognize cytoplasmic antigens of A. fumigatus, A. flavus, and A. niger by enzyme-linked immunosorbent assay. The MAbs can identify Aspergillus spp. both in frozen sections by immunofluorescence and in paraffin-embedded clinical specimens by immunofluorescence and immunoperoxidase staining.

Animals↗

Postpartum coma.

Explore the source record for details and available documents.

Adult↗

Protective isolation: who needs it?

Infection continues to be a major cause of morbidity and mortality in neutropenic patients following chemotherapy or bone marrow transplantation (BMT). Concerted efforts have been made to protect these patients from infection during the neutropenic period. Elaborate protocols to protect the patient from both intrinsic and extrinsic pathogens have been devised, ranging from simple single room isolation to laminar air flow units (LAFs), in association with varying degrees of antibiotic decontamination of the digestive tract. Comparative rates of infection using these techniques have varied in different studies, and their use has been somewhat controversial. More recently, prophylactic quinolone administration to neutropenic patients has significantly decreased the incidence of both Gram-negative septicaemia and pyrexial episodes, probably superseding any advantages which may have been conferred by previous regimens. LAFs with high efficiency particulate air filtration still appear to be the best means of protection against aspergillosis, but are expensive and would not be available for the majority of neutropenic patients. They should probably be allocated to patients who are most at risk; BMT recipients or others who may be expected to have a prolonged neutropenic period.

Bone Marrow Transplantation↗

An audit of ciprofloxacin use in a district general hospital.

An audit of ciprofloxacin use at Southmead Hospital, Bristol was carried out for forty patients treated in early 1992 employing a modified Delphi technique with six assessors. Most patients assessed (20/40, 50%) had urinary tract infections (UTIs), 5/40 (12.5%) had chest infections, 4/40 (10%) had bacterial gastroenteritis and 3/40 (7.5%) had either bacteraemia or infection following an orthopaedic procedure. A likely bacterial pathogen was isolated from 32/40 (80%) of patients; 14/32 (44%) had Pseudomonas aeruginosa infections and from the remainder Enterobacteriaceae including Salmonella spp. (non-typhoid) were cultured. Oral therapy with ciprofloxacin was used in 37 (93%) of the 40 patients, and the three others received iv treatment. In 21/35 (60%) of patients where an assessment was made by majority scoring, a quinolone was felt to be clinically justified. A quinolone was least likely to be thought justified if the patient had a chest infection. The assessors had few concerns about the effectiveness or toxicity of ciprofloxacin but for 41% (14/34) of patients, where there was a majority opinion, a cheaper alternative was felt to be available; most of these patients had hospital-acquired UTIs caused by Enterobacteriaceae. The duration of therapy was felt to be too long in 35% (10/29) of patients, mainly because of prolonged treatment of UTIs. In some cases of P. aeruginosa infection the assessors would have used higher doses than those prescribed. Ciprofloxacin was the quinolone of choice in 24/32 (75%) of assessable cases. Norfloxacin was chosen to treat UTI due to multi-resistant Enterobacteriaceae in 6.2% (2/32) cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Infective Agents↗

Lack of vessel wall elastolysis in human invasive pulmonary aspergillosis.

In experimental studies, the apparent ability of Aspergillus fumigatus isolates to produce elastase in agar plates correlates with their ability to cause invasive pulmonary aspergillosis in mice pretreated with cortisone. Thus, elastase production may govern the pathogenicity of particular isolates. If this is so, then disruption of the elastic layers within blood vessel walls in invasive aspergillosis would be expected. To test this hypothesis, tissue blocks were prepared from nine patients with invasive pulmonary aspergillosis. Separate but immediately adjacent histological sections were stained by the Grocott and periodic acid-Schiff methods for fungal hyphae and by the elastic van Gieson technique for elastic tissue. Comparison of those segments of vessel walls infiltrated by hyphae with those not infiltrated by hyphae showed no overall loss of elastic tissue. Material from five of the cases was also stained with an unconventional combination of histochemical stains, allowing accurate identification of both fungal hyphae and elastic laminae in the same histological sections. The results showed no more disruption of elastic laminae than would be expected from simple physical displacement of elastic laminae. We conclude that if elastolysis contributes at all to invasion of vessel walls by aspergilli, then it seems to be very localized and/or transient.

Adult↗

Production of species-specific murine monoclonal antibodies against Cryptococcus neoformans which recognize a noncapsular exoantigen.

Three monoclonal antibodies (MAbs), designated 7C5, 7C9, and 5G8, against a cytoplasmic antigen of Cryptococcus neoformans were produced. MAbs 7C5 and 7C9 recognize culture filtrate antigen (exoantigen) of both encapsulated and nonencapsulated isolates of this pathogen, which suggests that they do not recognize capsular polysaccharide material. This is supported by immunofluorescence data which show reactivity of all 3 MAbs to cytoplasm and cell membranes only. MAb 7C9 also recognized C. neoformans var. gattii antigens but no other fungal pathogens tested in an enzyme-linked immunosorbent assay, while 7C5 and 5G8 recognized antigens of the cross-reactive pathogen Trichosporon beigelii but did not recognize either C. neoformans var. gattii isolates or any other fungal antigens. By Western blot (immunoblot), 7C9 detected antigen at 110 to 120, 65 to 70, 45 to 50, and 36 to 38 kDa; in addition to the latter band, the other two MAbs recognized a band at approximately 30 kDa. All three MAbs were of the immunoglobulin G1 subclass. The two MAbs which are capable of reacting with noncapsular culture supernatant antigen have possible uses in serodiagnosis, particularly in AIDS patients infected with C. neoformans, since in this group the present latex agglutination test has some limitations.

Acquired Immunodeficiency Syndrome↗

The in-vitro antibiotic susceptibility of Chlamydia pneumoniae.

A cell culture technique was used to test the in-vitro susceptibility of the type strain of Chlamydia pneumoniae to 23 antibiotics including macrolides, tetracyclines and quinolones. The activity of the antibiotics tested was similar to previous findings with C. trachomatis. Clarythromycin had the lowest MIC overall (0.007 mg/l). Other macrolides were found to have similar MICs to erythromycin (0.06 mg/l). Both the macrolides and the tetracyclines were more active than the quinolones. It is proposed that the tetracyclines and erythromycin should be the drugs of choice for treating infections with C. pneumoniae; however several other antibiotics need to be evaluated.

4-Quinolones↗

A murine monoclonal antibody exhibiting high species specificity for Histoplasma capsulatum var. capsulatum.

A monoclonal antibody (mAb) exhibiting a high degree of species specificity for the yeast phase of the dimorphic fungus Histoplasma capsulatum was produced by a modification of the standard mAb production protocol. The technique for generating mAbs involved the use of the immunosuppressive drug cyclophosphamide to diminish the response in mice to immunodominant cross-reactive epitopes. This mAb exhibited clear specificity and did not react by ELISA with the closely related genera Blastomyces, Paracoccidioides and Sporothrix. In Western blots it recognized a linear determinant on a 70-75 kDa molecule in H. capsulatum antigen, with an extremely faint reactivity to antigens of identical molecular mass derived from Sporothrix and Paracoccidioides, and no reactivity against Blastomyces antigen.

Animals↗

Evidence that the M antigen of Histoplasma capsulatum var. capsulatum is a catalase which exhibits cross-reactivity with other dimorphic fungi.

A panel of monoclonal antibodies (Mabs) was raised against histoplasmin, the antigen derived from the mycelial phase of Histoplasma capsulatum var. capsulatum which contains the diagnostically useful H and M antigens. A number of Mabs were obtained which recognized a 70-75 kD component of an antigenic preparation of H. capsulatum var. capsulatum by Western blotting. When reacted with histoplasmin by Western blotting the Mabs recognized a similar 70-75 kD band, together with a series of higher molecular mass bands at approximately 130, 190 and 230 kD, a pattern which correlates strongly with both the published relative molecular mass (Mr) of the M antigen and the known subunit structure of the enzyme catalase. These Mabs were also shown to recognize a commercial preparation of Aspergillus niger catalase by ELISA. Other dimorphic fungi were also reactive with these Mabs by Western blotting, indicating the presence of common epitopes on the catalase molecules of these species.

Antibodies, Monoclonal↗

Murine monoclonal antibodies recognizing a non-capsular antigen that distinguishes between Cryptococcus neoformans var. neoformans and C. neoformans var. gattii.

A panel of 4 monoclonal antibodies (mabs) of the IgG1 subclass have been made against a cytoplasmic antigen of Cryptococcus neoformans. Mab 4E2 recognized isolates of C. neoformans var. gatti by enzyme-linked immunosorbent assay (ELISA), whilst the other antibodies did not recognize these antigens. By Western blot 4E2 recognized determinants at 110-125, 65-70, 45-50 and 36-38 kDa. Mabs 9E6, 7C7 and 5D9 recognized bands at 36-38 and approximately 30 kDa. All 4 mabs (4E2, 9E6, 7C7 and 5D9) recognized both non-encapsulated and encapsulated isolates of C. neoformans var. neoformans by ELISA, and in addition showed reactivity to only the cytoplasm and cell membrane of yeasts by immunofluorescence. Mab 7C7 recognized antigens of the closely related fungus Trichosporon beigelii by ELISA but did not recognize any other fungal antigens. The other 3 mabs showed no recognition of T. beigelii or any other fungal pathogens tested.

Animals↗