Biomedical subjects

Malcolm A Finkelman

Publications and source records attributed to Malcolm A Finkelman.

5 recordsLinked to original sources

PubMed2006

Reactivity of (1-->3)-beta-d-glucan assay with commonly used intravenous antimicrobials.

Forty-four intravenous antimicrobials were tested for the presence of (1-->3)-beta-d-glucan (BG). Colistin, ertapenem, cefazolin, trimethoprim-sulfamethoxazole, cefotaxime, cefepime, and ampicillin-sulbactam tested positive for BG at reconstituted-vial concentrations but not when diluted to usual maximum plasma concentrations. False-positive BG assays may occur when some antimicrobials are administered; however, this needs to be confirmed.

Anti-Bacterial Agents↗

PubMed2006

beta-Glucans in standardized allergen extracts.

BACKGROUND: Allergen extracts contain variable quantities of bacterial endotoxin. Recent studies have suggested that (1-->3)-beta-D-glucans (beta-glucans), also microbial cell wall components, may have adjuvant properties that could affect allergen immunotherapy. OBJECTIVE: To determine the quantities of beta-glucans in standardized allergen extracts. MATERIALS AND METHODS: Ninety-four lots of 13 standardized allergen extracts were tested for beta-glucan content by Glucatell assay, and for endotoxin content by a specific, chromogenic formulation of the Limulus amebocyte lysate test. RESULTS: Standardized allergen extracts contain variable quantities of endotoxins and beta-glucans. As in our previous work, endotoxin activity was greatest in cat pelt and Dermatophagoides farinae, and least in the pollens. There was no correlation between endotoxin and beta-glucan levels (r = 0.1887; P = 0.07). beta-Glucan content was highest for grass pollen (median content, 10.6 ng/ml; range, 0.4-41.8 ng/ml), ragweed pollen (32.9 ng/ml; range, 6.5-41.2 ng/ml), and cat pelt (25.5 ng/ml; range, 16.7-41.1 ng/ml), and lowest for cat hair (4.9 ng/ml; range, 1.2-10.3 ng/ml), D. farinae (1.2 ng/ml; range, 0.4-5.2 ng/ml) and Dermatophagoides pteronyssinus (1.8 ng/ml; range, 0.4-6.7 ng/ml). CONCLUSIONS: beta-Glucans are present in standardized allergen extracts. The effects of these quantities of beta-glucans on allergen immunotherapy and allergen skin testing require further study.

Allergens↗

PubMed2005

Multicenter clinical evaluation of the (1-->3) beta-D-glucan assay as an aid to diagnosis of fungal infections in humans.

BACKGROUND: Measurement of (1-->3)-beta-D-Glucan (BG) has emerged as an adjunct diagnostic strategy for invasive fungal infections (IFI). METHODS: Subjects at 6 clinical sites in the United States were enrolled as either fungal infection-negative subjects (n = 170) or subjects with proven or probable IFI according to European Organization for the Research and Treatment of Cancer/Mycoses Study Group criteria (n = 163). A central laboratory and 4 sites performed assays. A single sample was obtained per patient and was evaluated using an assay to detect serum BG derived from fungal cell walls (range, 0 to > 7000 pg/mL). RESULTS: At a cutoff of 60 pg/mL, the sensitivity and specificity of the assay were 69.9% and 87.1%, respectively, with a positive predictive value (PPV) of 83.8% and a negative predictive value (NPV) of 75.1%. At a cutoff value of 80 pg/mL, the sensitivity and specificity were 64.4% and 92.4%, respectively, with a PPV of 89% and an NPV of 73%. Of the 107 patients with proven candidiasis, 81.3% had positive results at a cutoff value of 60 pg/mL, and 77.6% had positive results at a cutoff value of 80 pg/mL. Of the 10 patients with aspergillosis, 80% had positive results at cutoff values of 60 and 80 pg/mL. The 3 subjects diagnosed with Fusarium species had positive results at a cutoff value of 60 pg/mL. Patients infected with Mucor or Rhizopus species (both of which lack BG) had negative results at both cutoff values, and of the 12 patients with Cryptococcus infection, 3 had positive results at a cutoff value of 60 pg/mL, and 2 had positive results at a cutoff value of 80 pg/mL. Of the subjects with proven positive results who were receiving antifungal therapy (n = 118), 72.9% had results positive for BG at a cutoff value of 60 pg/mL, and 69.5% had results positive for BG at a cutoff value of 80 pg/mL. The interlaboratory sample test r2 was 0.93. CONCLUSION: Reproducible assay results with high specificity and high PPV in a multicenter setting demonstrate that use of an assay to detect serum BG derived from fungal cell walls is a useful diagnostic adjunct for IFI.

Adult↗

PubMed2004

Beta-D-glucan as a diagnostic adjunct for invasive fungal infections: validation, cutoff development, and performance in patients with acute myelogenous leukemia and myelodysplastic syndrome.

The Glucatell (1-->3)- beta-D-glucan (BG) detection assay (Associates of Cape Cod) was studied as a diagnostic adjunct for invasive fungal infections (IFIs). On the basis of findings from a preliminary study of 30 candidemic subjects and 30 healthy adults, a serum BG level of >or=60 pg/mL was chosen as the cutoff. Testing was performed with serial serum samples obtained from 283 subjects with acute myeloid leukemia or myelodysplastic syndrome who were receiving antifungal prophylaxis. At least 1 serum sample was positive for BG at a median of 10 days before the clinical diagnosis in 100% of subjects with a proven or probable IFI. IFIs included candidiasis, fusariosis, trichosporonosis, and aspergillosis. Absence of a positive BG finding had a 100% negative predictive value, and the specificity of the test was 90% for a single positive test result and >or=96% for >or=2 sequential positive results. The Glucatell serum BG detection assay is highly sensitive and specific as a diagnostic adjunct for IFI.

Adult↗

PubMed2002

Production of recombinant endotoxin neutralizing protein in Pichia pastoris and methods for its purification.

Production of recombinant Limulus endotoxin neutralizing protein (rENP) was attained with the GS115 methylotrophic strain of Pichia pastoris transformed with a plasmid, bearing multiple ENP gene copies. The synthetic gene for Limulus ENP was cloned into the integrative plasmid pAO815 under the control of a methanol-inducible promoter. Clones containing a single enp insert were used to construct cassettes bearing 2 and 3 tandem copies of enp. These were then integrated at the HIS locus of P. pastoris GS115 (his4). Clones were chosen for their ability to produce rENP upon methanol induction in shaker flasks, and then the 1x, 2x, and 3x-enp strains were analyzed by Southern blot for the presence of the ENP gene(s). Isolate 3 x 5q, containing a 3x-enp cassette, was the best producer of rENP. Under optimal conditions this strain grown in a fed-batch mode produced yields of >500 mg rENP/L with an average of 5.46 mg rENP/g DCW. Purification of rENP from the clarified broth resulted in a yield of 35% and a purity of >86%. Glycosylated rENP, the main contaminant, was removed with a concanavalin-A column and characterized. The pure rENP neutralized lipopolysaccharide and had the mass, amino-acid composition and N-terminal sequence expected from the cloned gene.

Animals↗