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Biomedical subjects

J D Perry

Publications and source records attributed to J D Perry.

At least 37 records · Page 2Linked to original sources
PubMed2001

Synthesis and evaluation of novel fluorogenic substrates for the detection of bacterial beta-galactosidase.

AIMS: A widely used coumarin derivative is 7-hydroxy-4-methylcoumarin-beta-D-galactoside (4-methylumbelliferone-beta-D-galactoside; 4-MU-GAL). This galactoside is utilized as a substrate for the detection of the beta-galactosidase activity of coliform bacteria in water analysis. The intense fluorescence of coumarin-based molecules has enabled them to be incorporated into enzyme-based tests for the quantitative assay of indicator bacteria. The aim of this present study was to evaluate the potential of other coumarin derivatives, by synthesis of a selection of core coumarin molecules. METHODS AND RESULTS: Several coumarin derivatives were found to be more promising than 4-MU, with ethyl-7-hydroxycoumarin-3-carboxylate (EHC) giving a combination of greater fluorescence over a broad pH range and reduced growth inhibition with 12 representative coliform strains. On conversion to a beta-galactoside derivative, EHC-GAL generated a more rapid fluorescence than any other tested substrate. CONCLUSIONS: When tested in a broth assay format, based on most probable number (MPN), low numbers of coliforms were detected with EHC-GAL around 1 h earlier than with 4-MU-GAL. SIGNIFICANCE AND IMPACT OF THE STUDY: The present study suggests that EHC-GAL should be evaluated as a substrate for the detection of coliforms in water analysis, due to a combination of the following favourable features: (i) reduced toxicity; (ii) increased fluorescence; (iii) pH stability of fluorescence; and (iv) rapid detection.

Bacteriological Techniques↗
PubMed2001

Fluorogenic substrates for the detection of microbial nitroreductases.

AIMS: To synthesize and evaluate fluorogenic substrates for the detection of microbial nitroreductases. These substrates, all based on 7-nitrocoumarin, may be reduced to form fluorescent aminocoumarins. METHODS AND RESULTS: Thirty pathogenic microbial strains, including both bacteria and yeasts, were examined for nitroreductase activity in a whole-cell assay. All strains readily reduced each of the seven substrates to generate fluorescence, suggesting the widespread presence of nitroreductase activity in pathogenic bacteria. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: These novel substrates facilitate the direct detection of nitroreductase activity and have potential as sensitive indicators of microbial growth.

Bacteria↗
PubMed2001

Treatment of Staphylococcus aureus endocarditis using moxifloxacin.

The conventional treatment of staphylococcal endocarditis requires in-patient administration, is inconvenient, and is potentially toxic. Increasing experience with well-absorbed, well-tolerated and highly active agents such as the new quinolones has prompted interest in their use as therapeutic alternatives for the treatment of such infections. We describe a case of staphylococcal endocarditis which failed to respond to conventional therapy, but where the addition of moxifloxacin, an 8-methoxyquinolone, was curative.

Adult↗
PubMed2000

Transcaruncular approach to the medial orbit and orbital apex.

OBJECTIVE: To present a versatile approach to the medial orbit and orbital apex through the caruncle. DESIGN: Retrospective, noncomparative, case series with description of surgical technique. PARTICIPANTS: Twenty-five consecutive patients underwent orbital surgery by use of a transcaruncular approach. INTERVENTION: Inferior and medial wall fracture repair or orbital decompression by means of a transcaruncular or combined transfornix-transcaruncular approach. MAIN OUTCOME MEASURES: The surgical indications and complications were recorded for each patient. RESULTS: Ten patients (10 orbits) underwent combined inferior and medial orbital wall fracture repair through a combined transfornix-transcaruncular approach. In 8 of 10 (80%) orbits, the inferior oblique muscle was disinserted during surgery. Fifteen patients (24 orbits) underwent orbital decompression surgery for dysthyroid orbitopathy. An isolated transcaruncular approach was used in 5 of 24 orbits, and a combined transfornix-transcaruncular approach was used in 19 of 24 orbits. There were no complications related to either approach. CONCLUSIONS: Orbital bone removal and fracture reduction may be safely completed through a combined transfornix-transcaruncular approach. The transcaruncular approach provides excellent and safe exposure of the medial orbital wall, and it avoids scarring associated with the Lynch approach.

Decompression, Surgical↗
PubMed2000

Alizarin-beta-D-galactoside: a new substrate for the detection of bacterial beta-galactosidase.

We describe the synthesis of a new substrate for the detection of bacterial beta-galactosidase. This substrate, alizarin-beta-D-galactoside, is readily hydrolysed to release alizarin which complexes with various metal ions to form brightly coloured chelates. A total of 367 strains of Gram-negative bacteria were examined for their ability to hydrolyse three chromogenic substrates: alizarin-beta-D-galactoside (Aliz-gal), cyclohexenoesculetin-beta-D-galactoside (CHE-gal) and 5-bromo-4-chloro-3-indolyl-beta-D-galactoside (X-gal). A total of 182 strains (49.6%) were found to hydrolyse at least one of the three substrates. All of these 182 strains (100%) hydrolysed Aliz-gal whereas only 170 (93.4%) and 173 (95.1%) hydrolysed CHE-gal and X-gal, respectively. We conclude that alizarin-beta-D-galactoside is a highly sensitive substrate for the demonstration of beta-galactosidase.

Anthraquinones↗
PubMed2000

The safety and applications of acellular human dermal allograft in ophthalmic plastic and reconstructive surgery: a preliminary report.

PURPOSE: To describe the uses and determine the safety of a commercially available acellular dermal allograft in ophthalmic plastic and reconstructive surgery. The existing literature regarding current applications and results using acellular dermal allograft is reviewed. METHODS: The study design was a retrospective, noncomparative case series. Participants consisted of 63 consecutive patients undergoing ophthalmic plastic and reconstructive surgery using an acellular dermal matrix graft. The main intervention was placement of a dermal allograft. Outcome measures included the degree of clinical improvement and complications for each patient. RESULTS: We used AlloDerm (LifeCell Corporation, The Woodlands, TX, U.S.A.) as a posterior lamellar conjunctival spacer graft, a soft tissue interpositional graft, and an orbital implant wrapping material. Clinical improvement was noted in all cases. There were no complications attributable to the acellular dermal matrix material. CONCLUSIONS: We describe several novel ophthalmic plastic and reconstructive surgical applications using acellular dermal allograft tissue. This material may be used safely as a posterior lamellar conjunctival spacer graft, a soft tissue interpositional graft, and a wrapping material. Clinically, the allograft appears to be biocompatible, nontoxic, and nonallergenic in the orbit, eyelid, and midfacial tissues. Long-term data and studies comparing the efficacy of acellular dermal allograft with conventional materials are necessary.

Coated Materials, Biocompatible↗
PubMed2000

Strabismus after balanced medial plus lateral wall versus lateral wall only orbital decompression for dysthyroid orbitopathy.

PURPOSE: This study aimed to determine the relative incidence and time course of new-onset strabismus after balanced medial plus lateral wall orbital decompression versus decompression of the lateral wall alone for dysthyroid orbitopathy. METHODS: The study design was a retrospective nonrandomized comparative case series. Thirty-two consecutive patients underwent balanced medial plus lateral wall orbital decompression or lateral wall orbital decompression for dysthyroid orbitopathy. The incidence, duration, and treatment of postoperative strabismus was recorded for each patient. RESULTS: Significant preoperative strabismus was present in 31% (4/13 patients) of the balanced decompression group and in 26% (5/19 patients) of the lateral wall decompression group. Only 25% (1/4) of cases of preexisting strabismus in the balanced decompression group resolved postoperatively without muscle surgery, whereas 60% (3/5) of cases in the lateral wall decompression group resolved postoperatively without surgery. Preoperative strabismus was absent in 69% (9/13) of patients in the balanced decompression group and in 74% (14/19) of patients in the lateral wall decompression group. New-onset, persistent postoperative strabismus developed in 33% (3/9) of patients in the balanced decompression group and in 7% (1/14) of patients in the lateral wall decompression group. CONCLUSION: Lateral wall orbital decompression may produce less new-onset, persistent postoperative strabismus than balanced medial plus lateral wall orbital decompression for dysthyroid orbitopathy.

Adult↗
PubMed2000

Evaluation of p-naphtholbenzein-beta-D-galactoside as a substrate for bacterial beta-galactosidase.

We describe the synthesis of a new substrate for the detection of beta-galactosidase and evaluate its performance in comparison with 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal) and cyclohexenoesculetinbeta-D-galactoside (CHE-Gal). Of 206 Enterobacteriaceae strains able to hydrolyze X-Gal, 194 (94.2%) hydrolyzed CHE-Gal and 192 (93.2%) hydrolyzed p-naphtholbenzein-beta-D-galactoside (PNB-Gal). We conclude that PNB-Gal is an effective substrate for the detection of beta-galactosidase.

Chromogenic Compounds↗
PubMed1999

Visual dysfunction in patients receiving vigabatrin: clinical and electrophysiologic findings.

BACKGROUND: Vigabatrin is an antiepileptic drug that, although relatively well tolerated, is associated with visual field constriction and other visual disturbances of unclear origin. METHODS: We performed a complete neuroophthalmologic examination and electrophysiologic studies on 39 patients receiving vigabatrin and on 11 control patients. RESULTS: Nearly 50% of patients receiving vigabatrin had constricted visual fields compared with control patients. Some of the vigabatrin patients also had reduced visual acuity and abnormal color vision. In addition, most vigabatrin patients had abnormal electroretinographic results, the severity of which correlated strongly with the degree of visual field constriction. CONCLUSIONS: Vigabatrin can cause electrophysiologic evidence of retinal dysfunction and clinically detectable disturbances of visual sensory function.

Adult↗
PubMed1999

Bilateral ocular ischemic syndrome secondary to giant cell arteritis progressing despite corticosteroid treatment.

PURPOSE: To report the development of a bilateral ocular ischemic syndrome despite corticosteroid treatment in a patient with giant cell arteritis. METHOD: Case report. RESULTS: Despite receiving high-dose intravenous methylprednisolone and oral prednisone for biopsy-proven giant cell arteritis that presented as a severe anterior ischemic optic neuropathy in the right eye, a patient developed progressive ocular ischemia in that eye as well as an ocular ischemic syndrome in the fellow eye. CONCLUSIONS: Some patients with giant cell arteritis, possibly patients with other underlying systemic vasculopathies, are refractory to what should be adequate treatment with systemic corticosteroids and may develop a bilateral ocular ischemic syndrome.

Administration, Oral↗
PubMed1999

Evaluation of tube coagulase and a fluorogenic substrate for rapid detection of methicillin-resistant Staphylococcus aureus from selective enrichment broth in an outbreak of EMRSA 15.

We investigated the use of tube coagulase and a fluorescent substrate, N-t-BOC-val-pro-arg-7-amido-4-methylcoumarin for the rapid detection of MRSA in selective broth enrichment cultures during an outbreak. These methods were compared with direct plating of swabs and plating a selective broth enrichment culture using 200 screening swabs collected from forty patients during the investigation of an outbreak of E-MRSA 15. Overall 66 swabs were positive for MRSA following subculture of broth enrichment culture. Direct plating detected 25 (38%) positives, tube coagulase 37 (56%), and fluorescent substrate 49 (74%) respectively, although nine of the 49 turned out to be false reactions. When detection from individual patients was analyzed, selective broth subculture identified 28 patients colonized with MRSA. Direct plating detected only 12 (43%) of these patients. The tube coagulase and fluorescence methods detected MRSA in 17 (60%) and 19 (68%) patients respectively. The tube coagulase method was found to be 100% specific for MRSA suggesting its use as a rapid method for the detection of MRSA from selective enrichment broth.

Bacteriological Techniques↗
PubMed1999

Phototoxicity of rose bengal in mycological media--implications for laboratory practice.

The effects of Rose Bengal (RB) on plate counts of the bacteria Escherichia coli and Pseudomonas aeruginosa, and the yeast Saccharomyces cerevisiae, were studied under natural sunlight and artificial fluorescent lighting. While RB was not inherently toxic in darkness at concentrations found in mycological media, the illumination of media containing RB caused a decrease in colony counts in all cases, and especially for surface spread plates. A negative synergy was observed between chloramphenicol, RB and illumination using a spring water sample containing substantial numbers of Gram-negative bacteria. Exposure of media containing RB to moderate amounts of light during standard laboratory procedures may inhibit microbial growth, with positive benefits in relation to the suppression of contaminant bacteria, or negative implications where fungi are inhibited.

Anti-Bacterial Agents↗
PubMed1999

Glycopeptide tolerance in bacteria causing endocarditis.

Glycopeptides have been recommended as therapy for endocarditis. MICs and MBCs of vancomycin and teicoplanin were compared for 100 isolates from patients with proven bacterial endocarditis. MICs were generally lower for teicoplanin and tolerance to both agents was common. Almost all isolates of enterococci were tolerant to both glycopeptides. Among the streptococci, 78% were tolerant to teicoplanin and 57% to vancomycin. Similar findings were demonstrated for staphylococci. Although isolates appear sensitive to glycopeptides, bactericidal activity cannot always be predicted. If a glycopeptide is indicated for treatment of endocarditis, combination therapy with a suitable aminoglycoside should be considered unless MBC testing can be performed.

Anti-Bacterial Agents↗